106 results on '"Zhou, Yuhao"'
Search Results
2. Normal fat intake with high MUFA content and an appropriate SFA/MUFA/PUFA ratio improved the health of rats.
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Zhou, Yuhao, Yang, Ligang, Chu, Chu, Chen, Shiqing, Yue, Danwei, Hao, Yoong Jun, Sun, Guiju, and Xia, Hui
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EDIBLE fats & oils , *FREE fatty acids , *FAT , *MONOUNSATURATED fatty acids , *SATURATED fatty acids , *UNSATURATED fatty acids , *GLUTATHIONE peroxidase - Abstract
The quantity and quality of dietary fats have a significant impact on human health. This study aimed to investigate the effects of different cooking oils (olive oil (OO), soybean oil (SO), and blended oil (BO)) on growth, glucolipid metabolism, inflammation, and oxidative stress of rats fed normal and high‐fat diets. The results showed that the OO‐fed group had lower concentrations of serum triglyceride (TG), low‐density lipoprotein cholesterol (LDL‐C), malondialdehyde (MDA), oxidized LDL‐C (ox‐LDL‐C), and serum total cholesterol (TC) than the normal‐fat SO‐fed group, and rats in the BO‐fed group had lower values of serum interleukin‐6 (IL‐6), high‐sensitivity C‐reactive protein (hs‐CRP), tumor necrosis factor (TNF‐α), and nonesterified fatty acids (NEFA) than the normal‐fat SO‐fed groups. However, higher serum glutathione peroxidase (GSH‐Px) activity was observed in the OO‐fed group, while those fed with BO had higher serum superoxide dismutase (SOD) and GSH‐Px activities. Generally, most health‐beneficial fatty acid profiles have a high content of monounsaturated fatty acids (MUFAs), an appropriate saturated fatty acid (SFA)/MUFA/poly unsaturated fatty acid (PUFA) ratio, and a low n‐6/n‐3 PUFA ratio, while diets contained a high content of fat is detrimental to health. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Design of a high-efficient metamaterial X-band absorber composed of a dielectric cylinder combined with a thin magnetic cylinder unit.
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Liu, Yutong, Zhou, Yuhao, Si, Kaixuan, Bie, Shaowei, and Jiang, Jianjun
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DIELECTRIC materials , *DIELECTRICS , *METAMATERIALS , *MAGNETIC materials , *DIELECTRIC loss , *MAGNETIC flux leakage - Abstract
High-efficient microwave absorbers (MAs) with excellent absorption performance and lightweight characteristics have important applications in the military and civil. Here, we propose a dielectric-magnetic hybrid microwave absorber composed of a lattice of dielectric cylinders combined with thin magnetic cylinders backed by a perfect electrical conductor ground plane. The dielectric material that is designed as the dielectric cylinder is based on multi-walled carbon nanotubes-epoxy (MWCNT-EP). The MWCNT-EP is prepared and the S-parameters are measured by the standard transmission/reflection (T/R) method. The thin magnetic cylinder is based on a commercial magnetic material with a height of only 1 mm. With the coaction of magnetic loss and dielectric loss, the proposed microwave absorber's reflection loss is less than −20 dB under normal incident with a total height of 5 mm in the X-band. Besides, the dielectric-magnetic microwave absorber can maintain good absorption performance with different incident angles and polarizations. In this work, we provide a method to combine the properties of magnetic and dielectric material to construct the MA with high-efficient absorption performance. [ABSTRACT FROM AUTHOR]
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- 2022
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4. Perspectives of High‐Performance Li–S Battery Electrolytes.
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Liu, Jing, Zhou, Yuhao, Yan, Tianying, and Gao, Xue‐Ping
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LITHIUM sulfur batteries , *POLYMER colloids , *POLYELECTROLYTES , *SOLID electrolytes , *ELECTROLYTES , *ENERGY density , *ENERGY storage , *DENDRITIC crystals - Abstract
Lithium–sulfur batteries with high energy density are considered to be one of the most promising candidates for the next‐generation energy storage devices. Electrolyte as the medium for Li+ transportation between the electrodes, also plays a crucial role in inhibiting the dissolution and diffusion of lithium polysulfides in Li–S batteries. The working mechanism of Li–S batteries in different electrolytes is classified into "solid‐liquid‐solid" and "solid‐solid" conversions. Under the "solid‐liquid‐solid" conversion, Li–S batteries would inevitably face the challenges such as "shuttle effect" that lead to poor cycle performance, and under the "solid‐solid" conversion, they would face interface mismatch that limits the utilization of sulfur with low energy density, while both conversion mechanisms cause uncontrollable Li dendrites on anode. According to the conversion mechanism, electrolytes can be divided into ether‐based, ionic liquid‐based, gel polymer electrolytes, and polymer‐based solid‐state electrolytes with "solid‐liquid‐solid" conversion, as well as carbonate‐based electrolytes and oxide/sulfide‐based solid‐state electrolytes with "solid‐solid" conversion. Based on the conversion mechanism of active materials in different electrolytes, the current status on the strategies from multiple perspectives are summarized to improve the electrochemical performance, with the hope to provide a comprehensive guideline toward the development of suitable electrolytes for Li–S batteries. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Simulated microgravity attenuates skin wound healing by inhibiting dermal fibroblast migration via F‐actin/YAP signaling pathway.
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Zhou, Yuhao, Lv, Wenjun, Peng, Xiufen, Cheng, Yansiwei, Tu, Yun, Song, Guanbin, and Luo, Qing
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HEALING , *REDUCED gravity environments , *CELLULAR signal transduction , *YAP signaling proteins , *FIBROBLASTS - Abstract
Skin and its cell components continuously subject to extrinsic and intrinsic mechanical forces and are mechanical sensitive. Disturbed mechanical homeostasis may lead to changes in skin functions. Gravity is the integral mechanical force on the earth, however, how gravity contributes to the maintenance of skin function and how microgravity in space affects the wound healing are poorly understood. Here, using microgravity analogs, we show that simulated microgravity (SMG) inhibits the healing of cutaneous wound and the accumulation of dermal fibroblasts in the wound bed. In vitro, SMG inhibits the migration of human foreskin fibroblast cells (HFF‐1), and decreases the F‐actin polymerization and YAP (yes‐associated protein) activity. The SMG‐inhibited migration can be recovered by activating YAP or F‐actin polymerization using lysophosphatidic acid (LPA) or jasplakinolide (Jasp), suggesting the involvement of F‐actin/YAP signaling pathway in this process. In SMG rats, LPA treatment improves the cutaneous healing with increased dermal fibroblasts in the wound bed. Together, our results demonstrate that SMG attenuates the cutaneous wound healing by inhibiting dermal fibroblast migration, and propose the crucial role of F‐actin/YAP mechano‐transduction in the maintenance of skin homeostasis under normal gravity, and YAP as a possible therapeutic target for the skin care of astronauts in space. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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6. Arbuscular mycorrhizal fungi improve growth and tolerance of Platycladus orientalis under lead stress.
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Zhou, Yuhao, Wei, Man, Li, Yanpeng, Tang, Ming, and Zhang, Haoqiang
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VESICULAR-arbuscular mycorrhizas , *LEAD , *FUNGAL growth , *SUPEROXIDE dismutase , *HOST plants , *PHOTOSYNTHESIS - Abstract
Platycladus orientalis is a significant woody plant for phytoremediation in heavy metals contaminated soils. The growth and tolerance of host plants under the lead (Pb) stress were enhanced by arbuscular mycorrhizal fungi (AMF). To evaluate the adjustment by AMF on growth and activity of antioxidant system of P. orientalis under Pb stress. The two-factor pot experiment was conducted with three AM fungal treatments (noninoculated, Rhizophagus irregularis, and Funneliformis mosseae) and four Pb levels (0, 500, 1000, and 2000 mg kg−1). AMF increased dry weight, phosphorus uptake, root vitality, and total chlorophyll content of P. orientalis in spite of Pb stress. Compared with nonmycorrhizal treatments, mycorrhizal P. orientalis had lower H2O2 and malondialdehyde (MDA) contents under Pb stress. AMF increased Pb uptake in roots and decreased the Pb translating to the shoots yet under Pb stress. Total glutathione and ascorbate in roots of P. orientalis were decreased by AMF inoculation. Mycorrhizal P. orientalis had higher superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S-transferase (GST) activities in shoots and roots than nonmycorrhizal counterparts. Mycorrhizal P. orientalis under Pb stress showed higher expression of PoGST1 and PoGST2 in roots than that in CK treatments. Future studies will explore the function of induced tolerance genes by AMF of P. orientalis under Pb stress. Arbuscular mycorrhizal fungi (AMF) decreased the reduced toxicity of lead to Platycladus orientalis under lead stress, including improving growth, root activity, photosynthesis, and antioxidant system activity, while reducing its oxidative damage. At the same time, lead inhibited the symbiosis between AMF and Platycladus orientalis. Inoculation of AMF improved the growth of P. orientalis and decreased the Pb accumulation and damage to P. orientalis under Pb stress. AMF improved the antioxidant system and relevant genes expression of P. orientalis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. A semismooth Newton based augmented Lagrangian method for nonsmooth optimization on matrix manifolds.
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Zhou, Yuhao, Bao, Chenglong, Ding, Chao, and Zhu, Jun
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NONSMOOTH optimization , *NEWTON-Raphson method , *PRINCIPAL components analysis , *NONLINEAR functions , *SUBMANIFOLDS , *RIEMANNIAN manifolds - Abstract
This paper is devoted to studying an augmented Lagrangian method for solving a class of manifold optimization problems, which have nonsmooth objective functions and nonlinear constraints. Under the constant positive linear dependence condition on manifolds, we show that the proposed method converges to a stationary point of the nonsmooth manifold optimization problem. Moreover, we propose a globalized semismooth Newton method to solve the augmented Lagrangian subproblem on manifolds efficiently. The local superlinear convergence of the manifold semismooth Newton method is also established under some suitable conditions. We also prove that the semismoothness on submanifolds can be inherited from that in the ambient manifold. Finally, numerical experiments on compressed modes and (constrained) sparse principal component analysis illustrate the advantages of the proposed method. [ABSTRACT FROM AUTHOR]
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- 2023
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8. Ink‐Assisted Laser‐Induced Heterogeneous Permanent/Erasable Nanostructures on Metals.
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Li, Ruihao, Zhou, Yuhao, Liu, Shiting, Huang, Min, and Jiang, Shaoji
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POLARITONS , *STRUCTURAL colors , *LASER plasmas , *NANOSTRUCTURES , *PRECIOUS metals , *IRRADIATION , *METALS - Abstract
Structural color fabrication attracting significant interest for science and art is usually restricted by costly and time‐consuming structuring processes or inerasable characteristics of structures. Herein, by developing a universal, low‐cost technical solution—the nanosecond laser irradiation of ink (Solvent Black 7) layers coated on metal—laser‐induced heterogeneous permanent/erasable nanostructures (LIHPEN) are produced successfully on multiple metals, especially noble metals, without ablation damage to intrinsic surfaces. LIHPEN consist of uniform laser‐induced periodic surface structures produced by surface plasmon polariton excitation of metals and can be extended into 2D hybrid micro/nanostructures by introducing the direct laser interference patterning technique. LIHPEN technology operated under a large processing parameter window can realize space‐selective erasability of prepared structures by controlling processing parameters, which determine the ink‐layer carbonization degree and thus the permanent or erasable characteristic. Because ink layers can be coated manually, in addition to realizing digital scanning patterns, LIHPEN technology can be integrated with traditional artistic techniques to solidify and color artworks without risk of information loss and leakage in digital copying. LIHPEN with good durability can exhibit vivid structural colors on metals, demonstrating its great potential in fields of artwork iridescent coloring, encryption, and anti‐counterfeiting, particularly those requiring customization, personalization, and rewritability. [ABSTRACT FROM AUTHOR]
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- 2023
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9. Shrinkage, Fatigue and Microstructural Characteristics of Vibration Mixing Cement Stabilized Macadam.
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Li, Xuelian, Zhou, Yuhao, Zhou, Zihan, Ning, Zuofei, Wang, Suiyuan, and Diab, Aboelkasim
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FATIGUE limit , *FATIGUE cracks , *FATIGUE life , *CEMENT mixing , *SERVICE life - Abstract
The cement stabilized macadam (CSM) is widely used in pavement bases in China and different countries, but it is prone to shrinkage and fatigue cracking, resulting in a decrease in the service life and quality of the pavement. The resistance to shrinkage and fatigue cracking substantially affects the durability of CSM base. The objective of this study is to investigate the effect of the vibration mixing technology on the cracking resistance and microstructural characteristics of vibration mixing CSM. The drying shrinkage, temperature shrinkage, and fatigue tests of the vibration mixing CSM and traditional two-cylinder continuous mixing (TTCM) CSM were carried out to analyze their shrinkage strain and fatigue life. The microstructure of the vibration mixing was inspected by the scanning electron microscopy (SEM). The results showed that the dry and temperature shrinkage performance as well as fatigue performance of the cement stabilized macadam can be improved by the utilization of vibration mixing technology. The long-term shrinkage properties of the vibrating mixing cement stabilized macadam were also better than those of traditional mixing. The temperature shrinkage coefficient of CSM was greatly decreased with the vibration mixing technology, which was more obvious from − 25 to − 10 °C. The fatigue life of the CSM had improved with the vibration mixing technology. The possible reason for the improved shrinkage performance and fatigue characteristics is that the mechanism of the vibration mixing promotes for better distribution of the hydration products, and a three-dimensional network structure is formed in the CSM. In short, the durability and service life of the pavement can be improved with the vibration mixing technology. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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10. Rapid Rotation of an Erupting Prominence and the Associated Coronal Mass Ejection on 13 May 2013.
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Zhou, Yuhao, Ji, Haisheng, and Zhang, Qingmin
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CORONAL mass ejections , *SOLAR cycle , *HELIOSEISMOLOGY , *CYLINDRICAL shells , *MAGNETIC flux , *ROTATIONAL motion , *OBSERVATORIES , *MOTION - Abstract
In this paper, we report the multiwavelength observations of an erupting prominence and the associated coronal mass ejection (CME) on 13 May 2013. The event occurs behind the western limb in the field of view of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) spacecraft. The prominence is supported by a highly twisted magnetic flux rope and shows rapid rotation in the counterclockwise direction during the rising motion. The rotation of the prominence lasts for ∼ 47 minutes. The average period, angular speed, and linear speed are ∼ 806 sec, ∼ 0.46 rad min−1, and ∼ 355 km s−1, respectively. The total twist angle reaches ∼ 7 π , which is considerably larger than the threshold for kink instability. Writhing motion during 17:42 – 17:46 UT is clearly observed by SWAP in 174 Å and Extreme-UltraViolet Imager (EUVI) on board the behind Solar Terrestrial Relations Observatory (STEREO) spacecraft in 304 Å after reaching an apparent height of ∼ 405 Mm. Therefore, the prominence eruption is most probably triggered by kink instability. A pair of conjugate flare ribbons and post-flare loops are created and observed by STA/EUVI. The onset time of writhing motion is consistent with the commencement of the impulsive phase of the related flare. The 3D morphology and positions of the associated CME are derived using the graduated cylindrical shell (GCS) modeling. The kinetic evolution of the reconstructed CME is divided into a slow-rise phase (∼ 330 km s−1) and a fast-rise phase (∼ 1005 km s−1) by the writhing motion. The edge-on angular width of the CME is a constant (60∘), while the face-on angular width increases from 96∘ to 114∘, indicating a lateral expansion. The latitude of the CME source region decreases slightly from ∼ 18∘ to ∼ 13∘, implying an equatorward deflection during propagation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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11. An Efficient Power Optimization Approach for Fixed Polarity Reed–Muller Logic Circuits Based on Metaheuristic Optimization Algorithm.
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Zhou, Yuhao, He, Zhenxue, Chen, Chen, Wang, Tao, Xiao, Limin, and Wang, Xiang
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METAHEURISTIC algorithms , *DIFFERENTIAL evolution , *LOGIC circuits , *MATHEMATICAL optimization , *COMBINATORIAL optimization , *LOGIC design - Abstract
With the emergence of the multicore architecture and the increase of chip operating frequency, power optimization has become a key step of circuit logic synthesis. Aiming at the XNOR/OR circuits, with the goal of minimizing power, construct the optimal polarity fixed-polarity Reed–Muller (FPRM) circuits power optimization scheme. However, the power optimization for FPRM circuits is a multipeak combinatorial optimization problem, we first propose a metaheuristic optimization algorithm (MOA), which includes the global exploration optimizer, local deep exploitation optimizer, and initial population and uses the proposed differential evolution optimization, fierce wolf siege algorithm-based tabu search, and improved skew tent map to make the population evolve. Based on the proposed Huffman tree construction algorithm and MOA, we propose an efficient power optimization approach (EPOA) to find the minimum power FPRM circuit. Experimental results on the benchmark circuits confirm the effectiveness of EPOA. [ABSTRACT FROM AUTHOR]
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- 2022
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12. Mechanisms of hormetic effects of ofloxacin on Chlorella pyrenoidosa under environmental-relevant concentration and long-term exposure.
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Zhou, Yuhao, Chen, Xinyang, Zhu, Yan, Pan, Xiangjie, Li, Wei, and Han, Jiangang
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- 2024
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13. Hybrid periodic microstructures fabricated on chromium films by SLM-assisted nanosecond laser processing.
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Zhou, Yuhao, Li, Ruihao, Liu, Shiting, Jiang, Shaoji, and Huang, Min
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DIFFRACTION gratings , *SPATIAL light modulators , *STRUCTURAL colors , *LASER machining , *THICK films , *TRANSMITTANCE (Physics) - Abstract
• A SLM-assisted ns-laser processing technique is proposed for fabricating large-area, uniform, and well-arranged periodic structures on Cr films. • 2. For 1000-nm thick Cr films, the processed surface exhibits hybrid periodic microstructures comprised by modulated grating (MG) and laser induced periodic surface structures (LIPSS), that is, MG-LIPSS, which displays vivid anisotropic structural colors. • 3. For 200-nm thick Cr films, the processed hybrid structures are a combination of MG and cracks, that is, MGC, which can be utilized as a transmission grating with diffraction effects. An effective technique for preparing different hybrid periodic structures on chromium (Cr) films of different thicknesses using a 1064-nm nanosecond laser assisted by spatial light modulator (SLM) is proposed. For 1000-nm Cr films, by combining periodic modulated grating (MG) patterned by SLM with laser-induced periodic surface structures (LIPSS), regular dual-scale MG-LIPSS can be fabricated, with the morphological characteristics controlled by laser fluence, effective pulse number, and MG period. Due to diffraction effects of MG and LIPSS, MG-LIPSS patterned surfaces exhibit vivid anisotropic structural colors. In contract to MG-LIPSS, complex periodic structures consisting of MG and cracks (MGC) are fabricated on 200-nm Cr films due to the more significant thermal stress of a thinner film. Although the cracks of MGC distributed randomly, MGC show a long-range order characteristic with a certain transmittance, which can be utilized as a transmission grating with diffraction effects. These results demonstrate that optical field modulated laser machining based on SLM offers an efficient, cost-effective, and controllable method for fabricating large-area periodic structures on Cr films. Moreover, variations in film thickness can be employed to explore hybrid microstructures with specific properties, and thus utilized in diverse applications, such as optical components and anti-counterfeiting measures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle.
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Zhou, Yuhao, Ruan, Jiongming, Hong, Guotong, and Miao, Zheng
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RANKINE cycle , *DYNAMIC models , *THERMAL efficiency , *FLUID flow , *GASES , *QUANTUM cascade lasers , *WORKING fluids - Abstract
The control strategy is crucial for the effective and safe operation of the ORC system. A transient model of the ORC system was developed in the present work and validated by the experimental data of a 4 kW ORC prototype. Then, the effect of heat source temperature on the dynamic response and operation characteristics of the ORC system were analyzed. Five control strategies were compared: the constant working fluid mass flow rate mode, constant vapor superheat mode, constant vapor temperature mode, constant evaporation pressure mode and constant output power load mode. Under the constraint that the working fluid at the expander inlet should be superheated, we found that the constant vapor superheat mode enabled the safe operation with the largest range of heat source temperature, while the other four modes were only available for a certain temperature range. Apart from the constant output power mode, the constant evaporation pressure mode can also provide a relatively stable performance for the ORC unit. The variation of the thermal efficiency was limited when the heat source temperature was higher than 125 °C, except for the constant vapor temperature mode. Considering the high performance and stable operation of the ORC system, it is necessary to have different operation modes combined in the control strategy according to the specific working scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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15. Adaptive fuzzy command filtering control for nonlinear MIMO systems with full state constraints and unknown control direction.
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Zhou, Yuhao and Wang, Xin
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ADAPTIVE fuzzy control , *NONLINEAR systems , *MIMO systems , *ADAPTIVE control systems , *FUZZY logic , *NONLINEAR functions - Abstract
In this paper, the command-filter-based adaptive control strategy is proposed for a class of unknown nonlinear multiple input multiple output (MIMO) systems with full state constraints and unknown control direction, whose unknown nonlinear function is approximated by the fuzzy logic system (FLS). First, the fuzzy logic system (FLS) act as the universal approximator of the unknown nonlinear function and the command-filtered backstepping control method is utilized to handle the difficulty induced by the explosion of differentiation, as well as the compensating signals are designed to make up for the command filter error. Besides, the appropriate barrier Lyapunov function and the Nussbaum-type functions are employed to deal with the constraints violation and the unknown direction control gains, respectively. It is proved that the practical tracking performance of the system can be achieved with the designed protocols and all signals in the closed-loop system are semiglobal uniformly ultimately bounded. Finally, the simulation example is performed to verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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16. Multi-Objective Optimization of the Basic and Regenerative ORC Integrated with Working Fluid Selection.
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Zhou, Yuhao, Ruan, Jiongming, Hong, Guotong, and Miao, Zheng
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WORKING fluids , *THERMAL efficiency , *HEAT transfer , *RANKINE cycle , *COST control , *HEAT pipes - Abstract
A multi-objective optimization based on the non-dominated sorting genetic algorithm (NSGA-II) is carried out in the present work for the basic organic Rankine cycle (BORC) and regenerative ORC (RORC) systems. The selection of working fluids is integrated into multi-objective optimization by parameterizing the pure working fluids into a two-dimensional array. Two sets of decision indicators, exergy efficiency vs. thermal efficiency and exergy efficiency vs. levelized energy cost (LEC), are adopted and examined. Five decision variables including the turbine inlet temperature, vapor superheat degree, the evaporator and condenser pinch temperature differences, and the mass fraction of the mixture are optimized. It is found that the turbine inlet temperature is the most effective factor for both the BORC and RORC systems. Compared to the reverse variation of exergy efficiency and thermal efficiency, only a weak conflict exists between the exergy efficiency and LEC which tends to make the binary objective optimization be a single objective optimization. The RORC provides higher thermal efficiency than BORC at the same exergy efficiency while the LEC of RORC also becomes higher because the bare module cost of buying one more heat exchange is higher than the cost reduction due to the reduced heat transfer area. Under the heat source temperature of 423.15 K, the final obtained exergy and thermal efficiencies are 45.6% and 16.6% for BORC, and 38.6% and 20.7% for RORC, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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17. FLSGD: free local SGD with parallel synchronization.
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Ye, Qing, Zhou, Yuhao, Shi, Mingjia, and Lv, Jiancheng
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ARTIFICIAL neural networks , *SYNCHRONIZATION , *DISTRIBUTED computing , *TIMEKEEPING - Abstract
Synchronous parameters algorithms with data parallelism have been successfully utilized to accelerate the distributed training of deep neural networks (DNNs). However, a prevalent shortcoming of the synchronous methods is computation waste resulted from the mutual waiting among the computational workers with different performance and the communication delays at each synchronization. To alleviate this drawback, we propose a novel method, free local stochastic gradient descent (FLSGD) with parallel synchronization, to eliminate the waiting and communication overhead. Specifically, the process of distributed DNN training is firstly modeled as a pipeline which assembly consists of three components: dataset partition, local SGD, and parameter updating. Then, a novel adaptive batch size and dataset partition method based on the computational performance of the node is employed to eliminate the waiting time by keeping the load balance of the distributed DNN training. The local SGD and the parameter updating including gradients synchronization are parallelized to eliminate the communication cost by one-step gradient delaying, and the stale problem is remedied by an appropriate approximation. To our best knowledge, this is the first work focusing on decreasing both distributed training load balancing and communication overhead Extensive experiments are conducted with four state-of-the-art DNN models on two image classification datasets (i.e., CIFAR10 and CIFAR100) to demonstrate that the effectiveness of FLSGD outperforms the synchronous methods. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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18. Numerical analysis of the GaN trench MIS barrier Schottky diodes with high dielectric reliability and surge current capability.
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Zhou, Yuhao, Wu, Qianshu, Zhang, Qi, Li, Chengzhang, Zhang, Jinwei, Liu, Zhenxing, Zhang, Ke, and Liu, Yang
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SCHOTTKY barrier diodes , *GALLIUM nitride , *NUMERICAL analysis , *SCHOTTKY barrier , *DIELECTRICS , *BREAKDOWN voltage - Abstract
The commercialization of GaN-based Schottky barrier diodes in middle- and high- voltage applications still faces many challenges, in which the lack of an effective selective area p-type doping method is one of the main obstacles. This paper proposes novel vertical GaN-based Schottky diodes with trench MIS structure and an embedded p-GaN protection layer (junction-trench MIS barrier Schottky diodes, J-TMBS). The trench structure and lateral p-n junctions can be achieved by selectively etching the very thin p-GaN and then regrowing n-GaN. Therefore, the fabrication technology avoids the selective area p-type doping process, and the dry etching damage and poor sidewall regrowth interface issue, which are serious in GaN Merged pn/Schottky (MPS) diodes, can also be alleviated for the proposed J-TMBS. Compared with the optimized GaN trench MIS barrier Schottky (TMBS) diodes, the surge current capability and dielectric reliability of the proposed J-TMBS are significantly improved (the electric field of the dielectric layer and maximum lattice temperature under the surge test can be reduced by 448% and 202%, respectively). In addition, the specific on-resistance (Ron,sp) and breakdown voltage remain basically unchanged compared with TMBS. Compared with the optimized GaN MPS diodes, the proposed structure improves the specific on-resistance by 17.2% benefiting from the reduced area of the JFET region without degrading the reverse I–V characteristics and surge current capability. The proposed J-TMBS exhibits potential in practical high voltage (>600 V) application of GaN Schottky power diodes. [ABSTRACT FROM AUTHOR]
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- 2022
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19. Event-Triggered Adaptive Fault-Tolerant Control for a Class of Nonlinear Multiagent Systems With Sensor and Actuator Faults.
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Wang, Xin, Zhou, Yuhao, Huang, Tingwen, and Chakrabarti, Prasun
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FAULT-tolerant control systems , *MULTIAGENT systems , *NONLINEAR systems , *ACTUATORS , *CLOSED loop systems - Abstract
This paper investigates the leader-following consensus control problem for a class of nonlinear multiagent systems subject to sensor and actuator faults under a fixed directed graph. First, a fault compensation mechanism is proposed because of multiple faults wherein the adaptive parameters substitute the fault coefficients. Then, the command filtering method is employed to avoid the burst of complexity rendered by the duplicative differentiation of the virtual control signal. Furthermore, the neural networks-based state observers are designed to reconstruct the unmeasurable states of the nonlinear multiagent systems. According to the given design approach, a switching threshold-based event-triggered adaptive fault-tolerant control strategy is developed and ensures all the signals in the closed-loop system are semiglobally uniformly ultimately bounded (SGUUB). Finally, the simulation result is provided to demonstrate the validity of the presented method. [ABSTRACT FROM AUTHOR]
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- 2022
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20. Acoustic Multi-Parameter Early Warning Method for Transformer DC Bias State.
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Zhou, Yuhao and Wang, Bowen
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DC transformers , *WARNINGS , *POWER transformers - Abstract
The acoustic signal in the operation of a power transformer contains a lot of transformer operation state information, which is of great significance to the detection of DC bias state. In this paper, three typical parameters used for DC bias state detection are selected by comparing the acoustic variation of a 500 kV Jingting transformer substation No. 2 transformer with that of the core model built in the laboratory; then, acoustic samples of the 162 EHV normal state transformers are collected, and the distribution regularity of three typical parameters in normal state is given. Finally, according to the distribution regularity, clear warning threshold of typical parameters are given, and the DC bias cases from the 500 kV Jingting transformer substation are used to verify the effectiveness of the threshold. [ABSTRACT FROM AUTHOR]
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- 2022
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21. Command-filter-based adaptive neural tracking control for a class of nonlinear MIMO state-constrained systems with input delay and saturation.
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Zhou, Yuhao, Wang, Xin, and Xu, Rui
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MIMO systems , *KALMAN filtering , *ADAPTIVE control systems , *LYAPUNOV functions , *ADAPTIVE fuzzy control - Abstract
This paper investigates the problem of adaptive tracking control for a class of nonlinear multi-input and multi-output (MIMO) state-constrained systems with input delay and saturation. During the process of the control scheme, neural network is employed to approximate the unknown nonlinear uncertainties and the appropriate barrier Lyapunov function is introduced to prevent violation of the constraint. In addition, for the issue of input saturation with time delay, a smooth non-affine approximate function and a novel auxiliary system are utilized, respectively. Moreover, adaptive neural tracking control is developed by combining the command filtering backstepping approach, which effectively avoids the explosion of differentiation and reduces the computation burden. The introduced filtering error compensating system brings a significant improvement for the system tracking performance. Finally, the simulation result is presented to verify the feasibility of the proposed strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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22. DeFTA: A plug-and-play peer-to-peer decentralized federated learning framework.
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Zhou, Yuhao, Shi, Minjia, Tian, Yuxin, Ye, Qing, and Lv, Jiancheng
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FEDERATED learning , *RELIABILITY in engineering , *MACHINE learning , *DATA security , *DATA privacy , *SECURITY systems , *DENIAL of service attacks , *DEFECTORS - Abstract
Federated learning (FL) is a pivotal catalyst for enabling large-scale privacy-preserving distributed machine learning (ML). By eliminating the need for local raw dataset sharing, FL substantially reduces privacy concerns and alleviates the isolated data problem. However, in reality, the success of FL is predominantly attributed to a centralized framework called FedAvg [1] , in which workers are responsible for model training, and servers are in control of model aggregation. Nevertheless, FedAvg's centralized worker-server architecture has raised new concerns, including low scalability of the cluster, risk of data leakage, and central server failure or even defection. To overcome these challenges, we propose De centralized F ederated T rusted A veraging (DeFTA), a decentralized FL framework that serves as a plug-and-play replacement for FedAvg , bringing instant improvements to security, scalability, and fault-tolerance in the federated learning process. In essence, it primarily consists of a novel model aggregating formula with theoretical performance analysis, and a decentralized trust system (DTS) to significantly enhance system robustness. Extensive experiments conducted on six datasets and six basic models suggest that DeFTA not only exhibits comparable performance with FedAvg in a more realistic setting, but also achieves remarkable resilience even when 67% of workers are malicious. • A novel model aggregating formula is proposed that eliminates the aggregating bias in decentralized FL. • Selfish workers are introduced to the decentralized FL setting, which is simple and robust against backdoor attacks. • A general decentralized FL framework is proposed that features a drop-in replacement for the centralized FedAvg algorithm. • This replacement leads to improvements in data security and system reliability, with negligible model performance loss. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Preparation, pungency and bioactivity transduction of piperine from black pepper (Piper nigrum L.): A comprehensive review.
- Author
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Zou, Ruixuan, Zhou, Yuhao, Lu, Yujia, Zhao, Yuchen, Zhang, Na, Liu, Jing, Zhang, Yuhao, and Fu, Yu
- Subjects
- *
BLACK pepper (Plant) , *GENETIC transduction , *FOOD science , *EXTRACTION techniques , *TRPV cation channels , *FUNCTIONAL foods , *ANTIDEPRESSANTS , *NEUROPROTECTIVE agents - Abstract
Piperine, derived from black pepper (Piper nigrum L.), is responsible for the pungent sensation. The diverse bioactivities of piperine underscores its promising potential as a functional food ingredient. This review presents a comprehensive overview of the research progress in extraction, synthesis, pungency transduction mechanism and bioactivities of piperine. Piperine can be extracted through various methods, such as traditional, modern, and innovative extraction techniques. Its synthesis mainly included both chemical and biosynthetic approaches. It exhibits a diverse range of bioactivities, including anticancer, anticonvulsant, antidepressant, anti-inflammatory, antioxidant, immunomodulatory, anti-obesity, neuroprotective, antidiabetic, hepatoprotective, and cardiovascular protective activities. Piperine can bind to TRPV1 receptor to elicit pungent sensation. Overall, the present review can provide a theoretical reference for advancing the potential application of piperine in the field of food science. [Display omitted] • Piperine can be effectively obtained by extraction and synthesis methods. • Piperine exhibits various bioactivities in vitro and in vivo. • The binding of piperine to TRPV1 receptor elicits a pungent sensation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Comparative investigation of fatigue properties between additively and conventionally manufactured Invar 36 alloy.
- Author
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Liu, Xinxi, Zhou, Yuhao, Chen, Jie, An, Dayong, Li, Xifeng, and Chen, Jun
- Subjects
- *
ALLOY fatigue , *FATIGUE limit , *CRACK initiation (Fracture mechanics) , *MATERIAL plasticity , *HIGH cycle fatigue , *CRACK propagation (Fracture mechanics) , *FATIGUE cracks - Abstract
[Display omitted] • Tensile and fatigue properties of CM and PBF-LB samples are compared. • Integrated characterization approaches are employed to reveal fatigue mechanisms. • The importance of cellular structures on fatigue properties is highlighted. • The difference in fatigue properties between PBF-LB and CM samples is explained. The mechanical properties of ASTM F1684 (Invar 36) alloy manufactured via laser beam powder-bed-fusion (PBF-LB) technique are strongly influenced by the non-equilibrium solidification microstructure. Due to the complexity of printed microstructure, e.g. , the presence of melted pools, nano-precipitates, and high-density dislocations, it is very challenging to disentangle the specific mechanisms responsible for the fatigue properties. Here, a comparative investigation of the fatigue properties between PBF-LB and conventionally manufactured (CM) samples was conducted. Dedicated characterizations, including electron channeling contrast imaging (ECCI), and high-angular resolution EBSD (HR-EBSD), were performed. The mid-cycle (104–105 cycles) fatigue behaviors of both samples are comparable, while the fatigue resistance of PBF-LB sample becomes inferior at high-cycle range (≥ 106 cycles). This disparity can be ascribed to the competing effect between crack nucleation and propagation. PBF-LB samples are more susceptible to fatigue crack initiation due to the printed macro-defects. Whereas, the homogeneous plastic deformation and the grain fragmentation, both triggered by the ultrafine cellular structure, efficiently mitigate crack propagation rates. Based on these findings, the current understanding of the underlying mechanisms governing the fatigue performance of PBF-LB Invar 36 alloy is deepened, emphasizing the significant advantages of non-equilibrium solidification microstructure in retarding fatigue crack propagation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Insight into the multi-scale structure and retrogradation of corn starch by partial gelatinization synergizing with epicatechin/epigallocatechin gallate.
- Author
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Luo, Yunmei, Zhou, Yuhao, Liu, Haocheng, Liu, Xuwei, Xie, Xinan, and Li, Lu
- Subjects
- *
CORNSTARCH , *EPIGALLOCATECHIN gallate , *GELATION , *EPICATECHIN , *HYDROGEN bonding interactions , *FOOD quality , *STARCH - Abstract
Starch retrogradation is of great importance to the quality of starch-based food. This study investigated the effect of partial gelatinization (PG) synergizing with polyphenol (epicatechin, EC; epigallocatechin gallate, EGCG) on the multi-scale structure and short/long-term retrogradation of corn starch (CS). The PG synergizing with EC/EGCG substantially suppressed the short/long-term retrogradation properties of CS. These could be confirmed by the decreased storage modulus and viscosity, the relative crystallinity (1.54%, 3.56%), and the retrogradation degree (9.99%, 20.18%) of CS during storage for 1, 14 days after PG synergizing with EGCG and EC, respectively. This is because PG treatment promoted the hydrogen bond interaction between disordered starch molecules and EC/EGCG. These were proven by the larger aggregation, more and brighter fluorescents, and the reduced long/short-range order structures in CS after PG synergizing with EC/EGCG. This study is helpful for the development of foods with enhanced nutrition and low-retrogradation. [Display omitted] • PG (partial gelatinization) synergizing with polyphenol effectively delays retrogradation of corn starch. • The synergistic effects of epicatechin and epigallocatechin gallate with PG on starch retrogradation is different. • PG treatment promotes the hydrogen bond interaction between starch and polyphenol. • PG synergizing with polyphenol decreases the formation of crystalline structures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Revealing the superior oxidation resistance of alloy 690 in deaerated supercritical water at 600 °C through advanced characterization.
- Author
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Wang, Jiamei, Zhou, Yuhao, Wu, Yule, Han, Zhongli, Zhang, Lefu, Chen, Kai, and Shen, Zhao
- Subjects
- *
SUPERCRITICAL water , *OXIDATION kinetics , *CRYSTAL grain boundaries , *ALLOYS , *WEIGHT gain , *BOUNDARY layer (Aerodynamics) - Abstract
The corrosion behavior of a well-polished Alloy 690 in deaerated supercritical water at 600 °C was examined. The study found that the weight gain follows a near-cubic rate law. A key observation was that the direct external oxidation and the rapid transition from internal to external oxidation within the initial 24-h exposure are responsible for its superior oxidation resistance. As exposure time increases, the transformation of Cr-rich spinel oxides and Ni-rich networks in the internal oxidation zone into Cr 2 O 3 leads to the expansion of the protective chromia layer, effectively slowing down the oxidation process. Conversely, the Cr 2 O 3 layer at the grain boundaries (GBs) was less effective at preventing oxidation, resulting in a significantly faster oxidation rate in these areas compared to the bulk grains. The extensive GB oxidation exhibits little consequential correlation with carbides. • The oxidation kinetics of Alloy 690's in deaerated supercritical water (SCW) at 600 °C were investigated. • The rapid transition to external oxidation and the expansion of compact chromia layer are responsible for the superior oxidation resistance. • The severe GB oxidation proceeds about six times faster than the bulk matrix due to its faster elemental diffusivity along the migrated GB. • GB carbides does not exhibit any consequential relationship with the depth of Diffusion-induced grain migration or the extent of GB oxidation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Physiological-biochemical responses and transcriptomic analysis reveal the effects and mechanisms of sulfamethoxazole on the carbon fixation function of Chlorella pyrenoidosa.
- Author
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Zhou, Yuhao, Yue, Yujiao, Chen, Xinyang, Wu, Feifan, Li, Wei, Li, Pingping, and Han, Jiangang
- Published
- 2024
- Full Text
- View/download PDF
28. Tailoring molecular structures for enhanced anchoring of polysulfides in lithium–sulfur batteries.
- Author
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Liu, Jing, Zhou, Yuhao, Xiao, Zhenxue, Xue, Mengyuan, Liu, Sheng, and Yan, Tianying
- Subjects
- *
LITHIUM sulfur batteries , *MOLECULAR structure , *MULTIWALLED carbon nanotubes , *POLYSULFIDES , *ENERGY storage , *CARBONYL group - Abstract
The functional 2-fluorobenzamide is introduced onto carboxylic multiwalled carbon nanotubes to craft sulfur hosting materials with precisely tailored functional interfaces for Li–S batteries. The semi-ionic C–F bonds and carbonyl functional groups present a synergistic strategy via Li···O and Li···F bonds for anchoring LiPSs, resulting in outstanding electrochemical performance of the sulfur cathode. [Display omitted] • The feasibility of cooperative trapping of lithium polysulfides is demonstrated by strategically designed organic molecules using density functional theory. • Based on theoretical guidance, a series of benzamide-based organic molecules with semi-ionic C-F bonds and carbonyl functional groups were grafted onto carbon nanotubes as sulfur host materials for Li–S batteries. • The semi-ionic C-F bonds and carbonyl functional groups in organic molecules present a synergistic strategy to anchor lithium polysulfides through Li···O and Li···F bonds, resulting in enhanced electrochemical performance. Lithium–sulfur (Li–S) batteries, with promising potential for high energy density, remain compelling candidates for next-generation energy storage systems. However, they still suffer from huge challenges such as severe shuttle effects and sluggish redox kinetics. A strategic approach involves the meticulous design of host materials at the molecular level, emphasizing the construction of efficient sulfiphilic organic molecules as anchoring sites for lithium polysulfides (LiPS). In this study, a series of benzamides (benzamide, 2-fluorobenzamide, and 2,6-difluorobenzamide) are introduced onto carboxylic multiwalled carbon nanotubes (C-CNT) to graft sulfur hosting materials with tailored functional interfaces for Li–S batteries. Through a comparative study, we identify the semi-ionic C−F bond and carbonyl functional group as active centers, presenting a synergistic strategy via Li···O and Li···F bonds for anchoring LiPS. The optimized cathode material of sulfur-based carbon nanotubes grafted with 2-fluorobenzamide exhibits outstanding electrochemical activity, achieving a high reversible capacity of 944.8 mAh/g under a high sulfur loading (5.5 mg cm−2) and low electrolyte usage (8 µL mg−1). Our study underscores the potential of tailoring the molecular structure of host materials to effectively immobilize LiPS for high-performance Li–S batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Multi-condition operating characteristics and optimization of a small-scale ORC system.
- Author
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Xiao, Meng, Zhou, Yuhao, Miao, Zheng, Yan, Peiwei, Zhang, Manzheng, and Xu, Jinliang
- Subjects
- *
THERMAL efficiency , *RANKINE cycle , *FLUID flow , *WORKING fluids , *SPRING - Abstract
The multi-condition operating characteristics of an organic Rankine cycle (ORC) are crucial to the development of the practical unit. This work developed a steady-state model of a small-scale ORC prototype built and tested in the lab. The influence of heat source/sink parameters, component design, and operation strategies are analyzed. It is found that the optimal output power and thermal efficiency correspond to the similar expander rotating speed but diverse working fluid mass flow rate. The higher mass flow rate is beneficial to the output power whereas deteriorates the thermal efficiency. Heat source temperature and flow rates mainly affect the unit output power while the ambient temperature and humidity influence both the output power and thermal efficiency. The condenser fouling resistance leads to a significant reduction of expander output power and system thermal efficiency. However, the effect of the evaporator fouling resistance could be neglected due to its sufficient redundant area. The long-term climate conditions and operating strategies profoundly impact the unit's off-design performance. The annual constant output power operation can be achieved by adjusting the working fluid mass flow rate. The thermal efficiency of the unit is damaged while pursuing the output power stability in winter and spring. • A small-scale ORC prototype using R245fa is built and tested. • A steady-state model of the ORC prototype is developed and validated. • The influence of heat source/sink parameters, component design is analyzed. • Multi-condition operating characteristics under two control strategies are compared. • Annual performance of the system applied for different scenarios is predicted. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Experimental investigation of mechanical properties of NiTi superelastic shape memory alloy cables.
- Author
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Lian, Ming, Zhou, Yuhao, Wang, Yankai, and Su, Mingzhou
- Subjects
- *
SHAPE memory alloys , *STRAINS & stresses (Mechanics) , *NICKEL-titanium alloys , *CYCLIC loads , *CABLES , *LOADING & unloading - Abstract
As a self-centering element in a recoverable functional structure, shape memory alloys (SMAs) usually require a large diameter to provide sufficient bearing capacity, and pre-strain is applied to obtain good self-centering performance and initial stiffness. This study aims to explore the mechanical properties of large-diameter NiTi SMA cables and their potential applications in recoverable functional structures. Through the uniaxial tensile test of 11 SMA cables with 7 × 7 × 1.0 mm, the mechanical properties of SMA cables under different strain amplitudes, cyclic loading effects, loading rates, and different pre-strain modes were evaluated. The results indicate that the energy dissipation capacity of SMA cable increases with the increase of strain amplitude, but at the same time, it will reduce its self-centering capabilities. The equivalent viscous damping ratio decreases after the SMA cable enters the martensitic hardening stage. The residual strain of SMA cable depends on the combined effect of strain amplitude and number of cycles. The larger the strain amplitude and the number of cycles, the more significant the degradation of self-centering performance. After 20 times of constant amplitude loading and unloading, the mechanical properties of SMA cable are relatively stable. The reverse phase transformation stress of the pre-strained SMA cable gradually decreases with the increase of the tensile strain amplitude. The pre-strained SMA cable exhibits a stable restoring force strength in the sub-cycle, and the residual strain is zero. The test results support experimental data for applying large-diameter SMA cables in recoverable functional structures. • The equivalent viscous damping ratio decreases after the SMA cable enters the martensitic hardening stage. • The residual strain of an SMA cable is contingent upon the combined influence of strain amplitude and the number of cycles. • Faster loading raises reverse transformation stress, with little effect on forward transformation levels. • The reverse phase transformation stress in a pre-strained SMA cable decreases as the tensile strain amplitude increases. • In the sub-cycle, the pre-strained SMA cable maintains a stable restoring force strength, and the residual strain is zero. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Whole-Exome Sequencing Reveals Novel Variations in Patients with Familial Von Hippel−Lindau Syndrome.
- Author
-
Zhou, Yuhao, Liu, Jian, Chu, Liangzhao, Dong, Minghao, and Feng, Luqian
- Subjects
- *
GENETIC variation , *VON Hippel-Lindau disease , *GENETIC mutation - Abstract
Von Hippel−Lindau (VHL) syndrome is a rare disease that occurs in an autosomal-dominant genetic pattern. Due to the high genetic variability of VHL diseases, current studies have limited clinical value. Moreover, casual genetic variations in patients with VHL syndrome are still unclear. Here, we performed whole-exome sequencing of 25 individuals to identify reliable disease-related variations. Systemic computational analysis was performed for variant detection, and Sanger sequencing was used to validate detected mutations. Most of the known mutations in the VHL gene were observed in the studied population. In addition, a large fragment deletion in VHL exon 2 in the immediate family members of the last family was detected. This had not been reported earlier. Moreover, we identified 3 novel mutation sites in the MAP2K3 gene that may be involved in the occurrence and development of the VHL disease. These results demonstrated that the heterogeneous nature of VHL syndrome and novel mutational signatures may help to improve the diagnostic ability of VHL syndrome. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. In-situ template cooperated with thiourea to prepare oxygen/nitrogen co-doped porous carbons with adjustable pore structure for supercapacitors.
- Author
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Zhou, Yuhao, Ren, Xue, Song, Mingyuan, Du, Yueyao, Wan, Jiafeng, Wu, Guang, and Ma, Fangwei
- Subjects
- *
SODIUM alginate , *THIOUREA , *CARBON , *NITROGEN , *OXYGEN , *ELECTRIC capacity - Abstract
The exploration of preparing hierarchically porous carbons with adjustable pore structure from renewable biomass has attracted increasing attention by researchers. In this paper, the hierarchically porous carbon with excellent electrochemical properties is synthesized using renewable sodium alginate as a carbon source by in-situ pyrolysis of 'egg-box' structure with the addition of thiourea. The type/concentration of template resources and the thiourea additive have an important influence on the regulation of pore structure and the content of heteroatom here. More importantly, the doping of graphitic-N is conducive to enhancing the cycle stability of the electrode material. The PCNS–Zn sample has the most outstanding electrochemical performance with the high specific capacitance of 350 F g−1 at 1 A g−1 and the good rate capability of 82% capacitance retention at 50 A g−1. In addition, PCNS–Zn electrode shows a prominent cycle life with the capacitance retention rate of 90.4% at 5 A g−1 after 5000 cycles. From the perspective of sustainability, low cost and easy operation, this scheme has a broad development prospect for preparing porous carbon with controllable pore structure. • Porous carbons have been prepared by assembling of alginate and divalent cationic. • The template sources have an influence on the pore structure and nitrogen species. • Thiourea could regulate the size of template nano particles. • The doping of graphitic-N is conducive to enhance the cycle stability. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
33. In-situ template cooperated with thiourea to prepare oxygen/nitrogen co-doped porous carbons with adjustable pore structure for supercapacitors.
- Author
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Zhou, Yuhao, Ren, Xue, Song, Mingyuan, Du, Yueyao, Wan, Jiafeng, Wu, Guang, and Ma, Fangwei
- Subjects
- *
SODIUM alginate , *THIOUREA , *CARBON , *NITROGEN , *OXYGEN , *ELECTRIC capacity - Abstract
The exploration of preparing hierarchically porous carbons with adjustable pore structure from renewable biomass has attracted increasing attention by researchers. In this paper, the hierarchically porous carbon with excellent electrochemical properties is synthesized using renewable sodium alginate as a carbon source by in-situ pyrolysis of 'egg-box' structure with the addition of thiourea. The type/concentration of template resources and the thiourea additive have an important influence on the regulation of pore structure and the content of heteroatom here. More importantly, the doping of graphitic-N is conducive to enhancing the cycle stability of the electrode material. The PCNS–Zn sample has the most outstanding electrochemical performance with the high specific capacitance of 350 F g−1 at 1 A g−1 and the good rate capability of 82% capacitance retention at 50 A g−1. In addition, PCNS–Zn electrode shows a prominent cycle life with the capacitance retention rate of 90.4% at 5 A g−1 after 5000 cycles. From the perspective of sustainability, low cost and easy operation, this scheme has a broad development prospect for preparing porous carbon with controllable pore structure. • Porous carbons have been prepared by assembling of alginate and divalent cationic. • The template sources have an influence on the pore structure and nitrogen species. • Thiourea could regulate the size of template nano particles. • The doping of graphitic-N is conducive to enhance the cycle stability. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
34. The Design of a Remote Online Holistic Monitoring System for a Wind Turbine.
- Author
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Zhao, Long, Zhou, Yuhao, Matsuo, Igor B. M., Korkua, Suratsavadee Koonlaboon, and Lee, Wei-Jen
- Subjects
- *
SYSTEM downtime , *WIND turbines , *ONLINE monitoring systems , *RENEWABLE energy sources , *RENEWABLE natural resources , *INDUCTION generators , *UNINTERRUPTIBLE power supply , *FIELD programmable gate arrays - Abstract
As one of the most promising renewable energy resources, a large amount of wind energy has been implemented all around the world since 1990s. Increasing the size of the wind turbines and the harsh operating environment lead to the higher failure rates on the wind turbines compared with the other renewable resources. As a result, not only unplanned maintenance and repairments increases but also the downtime of the wind turbine increases the operational cost significantly. In addition, the long-distance transmission lines are required to transfer the wind generation power to the load centers due to the remote operation location of the wind farms. To improve the power transfer capability, the series-compensated lines are adopted in many cases. However, subsynchronous control interactions (SSCI) could happen between the series-compensated transmission lines and the wind turbines. This may damage the wind turbine components severely and cause stability issues in the power grids. Currently, various condition monitoring systems have been developed and applied for the wind turbines. Different SSCI detection mechanisms are also proposed in many studies. This article proposes a field-programmable gate array CPU-based holistic monitoring system which not only provides both condition and SSCI monitoring functions simultaneously in real time but also records the necessary data for the postevent analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
35. Potential of the Commercial Sector to Participate in the Demand Side Management Program.
- Author
-
Zhao, Long, Zhou, Yuhao, Quilumba, Franklin L., and Lee, Wei-Jen
- Subjects
- *
LOAD management (Electric power) , *PUBLIC utilities , *ELECTRIC power distribution grids , *SMART power grids , *ENERGY storage , *ELECTRIC power conservation - Abstract
The demand side management (DSM) has been conceived to improve the efficiency and flexibility of the power grids. Currently, different types of DSM programs, such as demand response, the efficiency of power delivery, heating, ventilation, and air conditioning (HVAC) improvements and distributed energy storage, have been developed and implemented by different utility companies. Since DSM is not a one-size-fit-all program, detailed consumers’ consumption data are required to both develop and improve effective DSM programs for different consumers. The rapid expansion of the advanced metering infrastructure in recent years has produced an enormous amount of data which can be utilized by utility companies for the DSM applications. Based upon the consumption characteristics of different types of consumers, various DSM programs can be developed and applied accordingly. This article analyzes and studies the practical smart meter data of commercial consumers from New York City considering the potential of commercial consumers’ participation for DSM applications, and it provides a better understanding of the power consumption pattern of commercial consumers in the urban area. Both utility companies and commercial consumers could benefit from this article to develop and participate in DSM programs, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
36. A Dynamic Weighted Aggregation Equivalent Modeling Approach for the DFIG Wind Farm Considering the Weibull Distribution for Fault Analysis.
- Author
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Zhou, Yuhao, Zhao, Long, Matsuo, Igor B. M., and Lee, Wei-Jen
- Subjects
- *
WIND power plants , *WEIBULL distribution , *INDUCTION generators , *WIND speed , *WIND power , *OFFSHORE wind power plants - Abstract
The developing process of the aggregated dynamic equivalent model (DEM) for doubly-fed induction generator (DFIG) wind farms could be less computational and more efficient compared with the multimachine DEM, but less accurate when wind speed differences exist inside the wind farm. In addition, the wind speed differences contribute to the different activation patterns of the crowbar systems of DFIGs. Therefore, a dynamic weighted aggregation modeling approach is proposed in this paper to improve the applicability of the aggregated DEM for DFIG wind farm. First, the Gaussian density distance clustering algorithm is applied to segment the wind speed power curve into different zones such that each segmented zone is corresponded to one equivalent aggregated machine. Then the dynamic weighted aggregation equivalent model could be developed based on the conventional aggregated DEM, where the weighting factors for each generator are calculated according to the Weibull distribution of wind speeds. Different scenarios are simulated in MATLAB/Simulink environment to analyze the applicability of the proposed dynamic weighting equivalent model. The simulation results show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
37. A Multistage Dynamic Equivalent Modeling of a Wind Farm for the Smart Grid Development.
- Author
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Zhou, Yuhao, Zhao, Long, Hsieh, Ting-Yen, and Lee, Wei-Jen
- Subjects
- *
OFFSHORE wind power plants , *WIND power plants , *PHASOR measurement , *DYNAMIC models , *PARAMETER identification , *MODAL analysis - Abstract
With high penetration level of wind generation, it is critical to establish a robust dynamic equivalent model (DEM) of the wind farm for system's stability analysis and smart grid development. Since wind farms may have a multistage development and are installed with different wind turbines from different technologies and/or venders, in this paper, a wind farm model with different types of wind generators (WGs) is constructed according to Western Electricity Coordinating Council generic WG models. In order to describe the dynamic behavior of the wind farm during system disturbances, by applying the data from phasor measurement units, a multistage hierarchical parameter identification process based on heuristic algorithms is proposed to develop a DEM for the wind farm. Different scenarios are simulated to validate the effectiveness and robustness of the proposed equivalent model. In addition, the modal analysis is performed to further validate the proposed approach by comparing the eigenvalues between the detailed wind farm model and the equivalent model. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
38. Ultra‐Soft Neural Probe with a Temporary High‐Strength U‐Section Coating by Picosecond Laser Micromachining.
- Author
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You, Xiaoli, Sun, Fanqi, Zhou, Yuhao, Wang, Minghao, Xu, Mengfei, Yuan, Xichen, Chang, Honglong, Liu, Jingquan, and Ji, Bowen
- Subjects
- *
MICROMACHINING , *LASER beam cutting , *SURFACE coatings , *POLYETHYLENE glycol , *ELECTRICAL engineers - Abstract
This paper reports an ultra‐soft neural probe with a temporary high‐strength U‐section coating of polyethylene glycol (PEG) for the first time. Its fabrication is compatible with MEMS processes, and an ultrathin U‐section coating over the probe's back and sidewall is precisely formed by spinning and cold laser cutting. With this novel coating, the probe has both minimized cross‐sectional area and sufficient mechanical strength for low‐invasive penetration into the brain. Besides, the remained ultra‐soft deformable probe after PEG dissolution is expected to be the next generation of neural implants for chronic recording. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Exploring structural origins responsible for the exceptional mechanical property of additively manufactured 316L stainless steel via in-situ and comparative investigations.
- Author
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An, Dayong, Zhou, Yuhao, Liu, Xinxi, Wang, Haoliang, Li, Shilei, Xiao, Yao, Li, Rui, Li, Xifeng, Han, Xianhong, and Chen, Jun
- Subjects
- *
MECHANICAL behavior of materials , *MECHANICAL properties of metals , *MATERIAL plasticity , *STRAIN hardening , *DISLOCATION density - Abstract
• In-situ observation of the dislocation-scaled and grain-scaled microstructures evolution in the additively manufactured 316L stainless steel. Revealing of emission of abundant stacking faults from cellular structures at the yielding stage, for the first time, in the bulk samples. • Quantification of the total dislocation density (∼1015 m−2), the geometrically necessary dislocation density (1.5–2 × 1014 m−2) and the misorientation angle (0.05–0.1°) of the cellular structures using high-resolution electron backscatter diffraction combined with electron channeling contrast imaging. • Identification of the intrinsic dislocation configurations of cellular structures as faulted dipoles, which significantly modulating the dislocation/twining behaviors of additively manufactured 316L sample. • The extremely fine slip band spacing rising high passing stress, playing a decisive role in the high macroscopic yield strength of additively manufactured 316L sample. • Instead of work hardening capability, the maintained ductility of additively manufactured 316L sample attributed to a complex interplay of several modulated plastic deformation mechanisms regulated by the hierarchical microstructure. The laser beam powder-bed-fusion (PBF-LB) technique offers the possibility to fabricate metallic materials with unparalleled mechanical properties. However, due to the complexity of nonequilibrium solidification structures, untangling the role of specific structural features in influencing mechanical properties through post-mortem analysis remains a significant challenge. Here, we tracked the complete evolution of deformation microstructures in PBF-LB 316L stainless steel (SS) and conventionally manufactured (CM) counterparts using in-situ electron channeling contrast imaging (ECCI) in conjunction with high-angular resolution electron backscatter diffraction (HR-EBSD). Our findings underscore the importance of the intrinsic dislocation configuration, i.e. , faulted dipole, in modulating the plastic deformation behaviors of the PBF-LB sample. The periodic arrangement of faulted dipoles triggers a widespread activation of stacking faults (SFs) with extremely fine spacing at the yielding stage, resulting in a high passing stress (∼433 MPa) that is responsible for the high yield strength. Meanwhile, such configuration facilitates uniform plastic deformation and mediates twinning propensity, thereby alleviating stress concentrations and enhancing ductility. Moreover, by correlating the mechanical response with microstructural evolution, we establish a modified model for multiple strengthening mechanisms in the PBF-LB sample. Additionally, we examine the effect of nonequilibrium solidification structures on the strain rate sensitivity of PBF-LB samples. Taking 316L SS as an exemplar, our results extend the current understanding of the structural origins responsible for the exceptional mechanical properties of metals manufactured by PBF-LB. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Hydrophobic modification of cationic microblocked polyacrylamide and its enhanced flocculation performance for oily wastewater treatment.
- Author
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Zhou, Yuhao, Zheng, Huaili, Huang, Yaoyao, Zheng, Xinyu, Liu, Zenan, An, Yanyan, Zhao, Chun, and Liu, Yongzhi
- Subjects
- *
POLYACRYLAMIDE , *NUCLEAR magnetic resonance spectroscopy , *WASTEWATER treatment , *FLOCCULATION , *FOURIER transform infrared spectroscopy , *INTRINSIC viscosity - Abstract
In this study, a novel amphiphilic flocculant TP-ADL was synthesized using acrylamide, methacryloxyethyltrimethyl ammonium chloride and lauryl acrylate as monomers through UV-light-initiating template copolymerization technology. Copolymerization conditions were optimized towards higher intrinsic viscosity and conversion rate. The Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy (NMR) analysis confirms the functional groups composition in TP-ADL, and the thermogravimetric (TGA) analysis indicates its good thermal stability. Furthermore, the detailed 1H NMR and TGA analysis confirms the microblock structure in polymer chain. The amphiphilic rheological characteristics of copolymer were detected according to apparent viscosity. TP-ADL displayed superior flocculation efficiency towards oily wastewater in terms of oil and turbidity removal rate, and zeta potential. The median floc size (d50) and fractal dimension (Df) results indicate a large and compact floc structure. The synergistic effect between cationic microblock structure and inter-molecular hydrophobic association is the main reason for the better treatment efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
41. Biowaste-based porous carbon for supercapacitor: The influence of preparation processes on structure and performance.
- Author
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Song, Mingyuan, Zhou, Yuhao, Ren, Xue, Wan, Jiafeng, Du, Yueyao, Wu, Guang, and Ma, Fangwei
- Subjects
- *
SUPERCAPACITORS , *POWER capacitors , *MUNG bean , *BIOCHAR , *MICROPORES , *MICROPORE filling - Abstract
Graphical abstract Abstract Here, a series of porous carbon based supercapacitor electrode materials have been synthesized by means of pyrolysis and hydrothermal methods combining with KOH activation using the biomass wastes mung bean husks as resources. The influence of synthesis process on the morphology, structure and supercapacitor performance of mung bean husks derived porous carbons has been investigated systematically. Especially, it is found that these oxygen-containing groups on the biochar play a crucial role in fabricating the three-dimensional (3D) hierarchical porous structure carbon. The original bio-structured porous carbon (PC 3-600), the 3D architecture porous carbon (HPC 2-700) and the porous carbon block (HPPC 2-700) have a high specific surface area, and the former mainly contains micropores and the latter two possess multistage pores. The specific capacitance of PC 3-600 , HPC 2-700 and HPPC 2-700 is respectively up to 390 F g−1, 353 F g−1, 304 F g−1 at 1 A g−1, and still maintains as high as 287 F g−1, 270 F g−1 and 235 F g−1 with corresponding retention ratio of 73.5%, 76.48%, 77.3% even at a high current density of 50 A g−1. HPC 2-700 //HPC 2-700 symmetric supercapacitor achieves a high energy density of 20.4 Wh kg−1 at 872 W kg−1 in 1 M Na 2 SO 4 electrolyte. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. Robustness Analysis of Dynamic Equivalent Model of DFIG Wind Farm for Stability Study.
- Author
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Zhou, Yuhao, Zhao, Long, and Lee, Wei-Jen
- Subjects
- *
WIND power , *ELECTRIC power distribution grids , *WIND power plants , *ALGORITHMS - Abstract
With the wind power energy largely interconnected with power grid, it is necessary to develop a robust dynamic equivalent model of the wind farm for the system stability analysis and control. In this paper, a detailed wind farm model with doubly fed induction generators is established according to Western Electricity Coordinating Council benchmark test system. Then, the parameters identification process based on aggregation technique consisting of a hybrid algorithm combined improved-particle swarm optimization with improved-genetic algorithm is proposed for dynamic equivalent model development by using the measurement data from phasor measurement unit at the point of interconnection. Additionally, the robustness of the developed equivalent model is analyzed. The simulation results of the benchmark test system and IEEE-9 bus system demonstrate the effectiveness and robustness of the proposed equivalent modeling and identification methodology. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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43. One-step synthesis of FeS nanoparticles embedded in nitrogen-doped porous carbon for improved lithium storage properties.
- Author
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Zhou, Yuhao, Liu, Kun, Sun, Xiaodong, Zhang, Ning, Liu, Wenlong, Yang, Zhimo, Tao, Kairui, and Sun, Juncai
- Subjects
- *
LITHIUM , *DOPING agents (Chemistry) , *POROUS materials , *ELECTRIC conductivity , *ELECTRODE potential , *NITROGEN - Abstract
• FeS nanoparticles embedded in N -doped porous C is prepared by one-step strategy. • The N -doped C can improve conductivity, introduce defects and more active sites. • The FeS/NC electrode displays superior lithium-ion storage performance. • The electrochemical reaction mechanism is studied by ex-situ XPS. The electrode materials with simple preparation methods, good electrochemical performance, and cheap cost have broad application prospects in the field of electrochemistry. Herein, we propose one-step method for the direct sulfuration of iron-phthalocyanine (FePc) to produce FeS nanoparticles embedded in nitrogen-doped porous carbon (FeS/NC). Introducing porous carbon materials into the FeS nanoparticles can significantly restrain the huge volume expansion and enhance electrical conductivity. Nitrogen doping can further improve the electrical conductivity and introduce defects in the carbon host. The results show that the FeS/NC-750 demonstrates a discharge capacity of 834 mA h g−1after 100 cycles at 200 mA g−1. The FeS/NC anode still has a high discharge specific capacity of 612.4 mAh g−1 even after 500 cycles at 1000 mA g−1. The simple strategy provides an inexpensive and straightforward strategy for conversion of FePc into available FeS/NC anode materials, which presents that FeS/NC electrode has potential application value in lithium-ion batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. Deep eutectic solvents as new media for green extraction of food proteins: Opportunity and challenges.
- Author
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Zhou, Yuhao, Wu, Wei, Zhang, Na, Soladoye, Olugbenga P., Zhang, Yuhao, and Fu, Yu
- Abstract
[Display omitted] • The recent research progress on extraction of food proteins by DES is reviewed. • DES can exhibit high extraction efficiency in the extraction of food proteins. • The structure and activity of extracted proteins can completely be retained by DES-based method. • DES with low viscosity, high selectivity and back-extraction efficiency is needed. The constantly improved quality of life leads to increasing demand for high-quality food proteins. Thus, the high-efficiency extraction methods of food proteins are highly needed. However, the traditional alkali-solution and acid-isolation method employs a large amount of corrosive acid/alkaline solution, which not only pollutes the environment, but also causes denaturation of proteins. Therefore, developing a novel green extraction method is of great significance. Deep eutectic solvents (DES), characterized by good biodegradability, sustainability and low toxicity, have become a green solvent in the past years. Extraction of food proteins by DES can overcome the shortcomings of corrosive solvents (e.g. NaOH, HCl and H 2 SO 4) used in traditional methods, making it a promising novel green extraction method. In this work, the information on DES was firstly recapped. Furthermore, the latest research progress on the extraction of food proteins by DES was emphatically reviewed. In addition, the challenges and future perspectives for DES-assisted extraction were discussed. Overall, the DES-based methods exhibit high extraction efficiency in extracting animal and plant proteins, amino acids, and enzymes, while the extracted proteins were non-denatured. However, DES-based protein extraction method still faces some challenges, such as high viscosity, poor extraction selectivity and inefficient back-extraction method. The present work can provide a theoretical reference for applying DES in the green extraction of food proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. In situ investigation on plastic deformation behaviors in austenite-ferrite heterostructured stainless steel.
- Author
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Zhou, Yuhao, Xiao, Yao, Li, Rui, Gong, Weijia, and An, Dayong
- Subjects
- *
MATERIAL plasticity , *STAINLESS steel , *STRAIN hardening , *TENSILE tests , *STRESS concentration - Abstract
Heterostructured (HS) materials have attracted extensive attention due to their superior mechanical properties. However, there are still many fundamental issues to be solved, like the microstructural evolution process of the hetero-zones during deformation. Here we reported a HS 316L stainless steel generated by exploiting the chemical heterogeneity strategy via thermomechanical processing. The plastic deformation behaviors of the hetero-zones were investigated using three-point bending tests and interrupted tensile tests characterized by electron channeling contrast imaging (ECCI) combined with electron backscattered diffraction (EBSD) techniques. These in situ observations demonstrate the evolution of hetero deformation-induced (HDI) stress field near the austenite/ferrite interfaces in terms of geometrically necessary dislocation (GND) pileups, which can modulate the plastic deformation behaviors of both austenite and ferrite phases. At the early deformation regime, the imposed plastic deformation can be well maintained by the dense and homogeneous activation of slip systems in austenite phases and the stress concentration near austenite/ferrite interfaces can be alleviated by the gradual activation of plastic deformation in the ferrite phases. At the large deformation stage, a progressive twinning-induced plasticity (TWIP) effect caused by the chemical heterogeneity can provide a stable work hardening ability in a broad strain range, which can significantly enhance the ductility. At the late stage of deformation, strain-induced α′-martensite is also triggered, which provides an additional work-hardening ability. The strategy of micro-tuning deformation mechanisms by chemical heterogeneity is versatile and can be applied to many alloys. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. An integrated framework based on deep learning algorithm for optimizing thermochemical production in heavy oil reservoirs.
- Author
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Zhou, Yuhao and Wang, Yanwei
- Subjects
- *
HEAVY oil , *PETROLEUM reservoirs , *MACHINE learning , *DEEP learning , *OIL field flooding , *PETROLEUM engineering , *REINFORCEMENT learning - Abstract
The development of heavy oil reservoirs with active edge and bottom water is one of the most challenging problems in petroleum engineering. In response to the limited thermal recovery of these reservoirs, a multi-phase and multi-component numerical simulation model for thermal and chemical recovery is proposed. An edge-water assisted chemical flooding (EAC flooding) is proposed, which can improve oil displacement efficiency and sweep efficiency by rational utilization of edge-water energy when compounding multi-component chemical system. Then, a deep reinforcement learning algorithm is proposed to predict dynamic production parameters and determine the optimal working system to maximize the oil recovery according to the above mathematical model. The deep reinforcement learning (DRL) model can predict the dynamic production curves according to given states with optimal strategy. At the same time, the proposed model can determine the best conversion timing from cyclic steam stimulation to EAC flooding. Finally, the DRL model can automatically obtain the optimal working system, effectively improving the oil recovery while considering the economic benefits. Thus, the DRL model can solve traditional numerical simulation's time-consuming and labor-intensive challenges and accurately give the optimal working system for developing heavy oil reservoirs with edge water in the field. • A deep reinforcement learning-based model is developed to provide an optimal working system. •The DRL model can predict production performance with optimal strategy. •The model can predict the best conversion timing for different production stages. •The model can be used as a screening or decision-making tool for projects in the field. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. Correction to: FLSGD: free local SGD with parallel synchronization.
- Author
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Ye, Qing, Zhou, Yuhao, Shi, Mingjia, and Lv, Jiancheng
- Subjects
- *
SYNCHRONIZATION - Published
- 2022
- Full Text
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48. Improving PageRank using sports results modeling.
- Author
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Zhou, Yuhao, Wang, Ruijie, Zhang, Yi-Cheng, Zeng, An, and Medo, Matúš
- Subjects
- *
SPORTS tournaments , *RECOMMENDER systems , *INFORMATION filtering , *SPORTS , *EVALUATION methodology , *FUZZY numbers - Abstract
How to rank participants of a sports tournament is of fundamental importance. While PageRank has been extensively used for this task, the algorithm's superiority over simpler ranking methods has never been clearly demonstrated. We address this knowledge gap by comparing the performance of multiple ranking methods on synthetic datasets where the true ranking is known and the methods' performance can be thus quantified by standard information filtering metrics. Using sports results from 18 major leagues, we calibrate a state-of-art model, a variation of the classical Bradley–Terry model, for synthetic sports results. We identify the relevant range of parameters under which the model reproduces statistical patterns found in the analyzed empirical datasets. Our evaluation of ranking methods on the synthetic datasets shows that PageRank outperforms the benchmark ranking by the number of wins only early in a tournament when a small fraction of all games have been played yet. Increased randomness in the data due to home team advantage, for example, further reduces the range of PageRank's superiority. We propose a new PageRank variant that combines forward and backward propagation on the directed network representing the input sports results. The new method outperforms PageRank in all evaluated settings and, when the fraction of games played is sufficiently small and the sport is not too random, it outperforms also the ranking by the number of wins. Beyond the presented comparison of ranking methods, our work paves the way for designing optimal ranking algorithms for sports results data. • PageRank is often applied on sports data to rank teams or individuals. • We set up and calibrate a model to create synthetic sports results. • Synthetic data are used to assess various ranking algorithms. • We find that PageRank performs well only when there is little randomness in data. • We propose a PageRank variant that outperforms PageRank in all evaluated settings. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. Investigating the Action Mechanism of Titanium in Alumina–Magnesia Castables by Adding Different Ti-Bearing Compounds.
- Author
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Tang, Hai, Zhou, Yuhao, and Yuan, Wenjie
- Subjects
- *
TITANIUM , *THERMAL shock , *CRYSTAL lattices , *HEAT treatment , *THERMAL resistance - Abstract
To investigate the action mechanism of titanium, the effects of different Ti-bearing compounds, including CaTiO3, MgTiO3, and nano-TiO2, on the properties of alumina–magnesia castables were studied. By analyzing the phase compositions, microstructures, and physical and mechanical properties of the castables, it was demonstrated that an intermediate product, CaTiO3, was first generated. This was then consumed by solid-solution reactions, and titanium was involved in the liquid formation as the temperature increased. The solid-solution reaction of CA6 (CaAl12O19) was more prominent due to the incorporation of more titanium in the crystal lattice of CA6 instead of spinel (MgAl2O4). Moreover, the liquid formation was strongly promoted when more titanium accompanied the calcium, which finally accelerated the densification and improved the strengths of alumina–magnesia castables. On the whole, castables with CaTiO3 addition presented higher bulk density and excellent strength after the heat treatment. Besides, the castables with 2 wt.% CaTiO3 contents were estimated to possess greater thermal shock resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. Simulated Microgravity Inhibits Rodent Dermal Fibroblastic Differentiation of Mesenchymal Stem Cells by Suppressing ERK/β-Catenin Signaling Pathway.
- Author
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Cheng, Yansiwei, Zhou, Yuhao, Lv, Wenjun, Luo, Qing, and Song, Guanbin
- Subjects
- *
MESENCHYMAL stem cell differentiation , *CELLULAR signal transduction , *WNT signal transduction , *CATENINS , *EXTRACELLULAR signal-regulated kinases , *REDUCED gravity environments , *MESENCHYMAL stem cells , *PROTEIN kinases - Abstract
Studies have shown that bone marrow-derived mesenchymal stem cells (BMSCs) can differentiate into dermal fibroblasts to participate in skin-repairing. However, at present, little is known about how microgravity affects dermal fibroblastic differentiation of BMSCs in space. The aim of this study was to investigate the effect of simulated microgravity (SMG) on the differentiation of BMSCs into dermal fibroblasts and the related molecular mechanism. Here, using a 2D-clinostat device to simulate microgravity, we found that SMG inhibited the differentiation and suppressed the Wnt/β-catenin signaling and phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2). After upregulating the Wnt/β-catenin signaling with lithium chloride (LiCl) treatment, we found that the effect of the differentiation was restored. Moreover, the Wnt/β-catenin signaling was upregulated when phosphorylation of ERK1/2 was activated with tert-Butylhydroquinone (tBHQ) treatment. Taken together, our findings suggest that SMG inhibits dermal fibroblastic differentiation of BMSCs by suppressing ERK/β-catenin signaling pathway, inferring that ERK/β-catenin signaling pathway may act as a potential intervention target for repairing skin injury under microgravity conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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