36 results on '"Luyu Wang"'
Search Results
2. Improved Vth Stability and Gate Reliability of GaN-Based MIS-HEMTs by Employing Alternating O2 Plasma Treatment
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Xinling Xie, Qiang Wang, Maolin Pan, Penghao Zhang, Luyu Wang, Yannan Yang, Hai Huang, Xin Hu, and Min Xu
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AlGaN/GaN MIS-HEMT ,threshold voltage stability ,gate reliability ,Chemistry ,QD1-999 - Abstract
The Vth stability and gate reliability of AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) with alternating O2 plasma treatment were systematically investigated in this article. It was found that the conduction band offset at the Al2O3/AlGaN interface was elevated to 2.4 eV, which contributed to the suppressed gate leakage current. The time-dependent dielectric breakdown (TDDB) test results showed that the ALD-Al2O3 with the alternating O2 plasma treatment had better quality and reliability. The AlGaN/GaN MIS-HEMT with the alternating O2 plasma treatment demonstrated remarkable advantages in higher Vth stability under high-temperature and long-term gate bias stress.
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- 2024
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3. Phosphorus‐Doped Porous Carbon Coated Graphite Felt as An Efficient and Reusable Cathode for Electro‐Fenton Degradation of Parabens
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Jia Shen, Yating Zhu, Fengmei Zhou, Luyu Wang, Dr. Manli Guo, and Dr. Yujuan Cao
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doping ,electro-Fenton ,environmental chemistry ,graphite felt ,parabens ,Industrial electrochemistry ,TP250-261 ,Chemistry ,QD1-999 - Abstract
Abstract Pharmaceuticals and personal care products (PPCPs) are currently drawing significant attention due to their environmental impact. Electro‐Fenton, one of the advanced oxidation processes (AOPs), is an efficient and comprehensive technology to degrade all kinds of organic pollutants, but the degradation efficiency relies on cathode material. In this work, phosphorus‐doped porous carbon material coated graphite felt (P‐GF) was prepared by adopting phytic acid as a phosphorus source through high temperature solid‐state method. The microstructure and the elements composition of this fabricated material were investigated by SEM, BET and XPS. With phosphorus doping and plenty of carbon porous structures, the hydrophilicity and infiltrating property of the P‐GF had been greatly improved. The prepared P‐GF material enhanced the electrochemical reduction of O2 and could significantly enhance the yield of H2O2. It was used as a cathode to degrade pollutants under a constant potential, and methylparaben (MePa) was chosen as a research model for optimizing the experimental conditions and analyzing the possible degradation pathway. The P‐GF cathode achieved an excellent ability of degrading nearly 100 % of methylparaben within 3 h. The simultaneous removal ability of the P‐GF to four parabens was impressed. Additionally, the P‐GF material exhibited outstanding reusability.
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- 2023
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4. A Novel Atomic-Level Post-Etch-Surface-Reinforcement Process for High-Performance p-GaN Gate HEMTs Fabrication
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Luyu Wang, Penghao Zhang, Kaiyue Zhu, Qiang Wang, Maolin Pan, Xin Sun, Ziqiang Huang, Kun Chen, Yannan Yang, Xinling Xie, Hai Huang, Xin Hu, Saisheng Xu, Chunlei Wu, Chen Wang, Min Xu, and David Wei Zhang
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etch induced damage ,surface reinforcement ,interface state ,p-GaN gate HEMTs ,Chemistry ,QD1-999 - Abstract
A novel atomic-level post-etch-surface-reinforcement (PESR) process is developed to recover the p-GaN etching induced damage region for high performance p-GaN gate HEMTs fabrication. This process is composed of a self-limited surface modification step with O2 plasma, following by an oxide removal step with BCl3 plasma. With PESR process, the AlGaN surface morphology after p-GaN etching was comparable to the as-epitaxial level by AFM characterization, and the AlGaN lattice crystallization was also recovered which was measured in a confocal Raman system. The electrical measurement further confirmed the significant improvement of AlGaN surface quality, with one-order of magnitude lower surface leakage in a metal-semiconductor (MS) Schottky-diode and 6 times lower interface density of states (Dit) in a MIS C-V characterization. The XPS analysis of Al2O3/AlGaN showed that the p-GaN etching induced F-byproduct and Ga-oxide was well removed and suppressed by PESR process. Finally, the developed PESR process was successfully integrated in p-GaN gate HEMTs fabrication, and the device performance was significantly enhanced with ~20% lower of on-resistance and ~25% less of current collapse at Vds,Q bias of 40 V, showing great potential of leverage p-GaN gate HEMTs reliability.
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- 2023
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5. A Novel Si Nanosheet Channel Release Process for the Fabrication of Gate-All-Around Transistors and Its Mechanism Investigation
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Xin Sun, Dawei Wang, Lewen Qian, Tao Liu, Jingwen Yang, Kun Chen, Luyu Wang, Ziqiang Huang, Min Xu, Chen Wang, Chunlei Wu, Saisheng Xu, and David Wei Zhang
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nanosheet ,gate-all-around ,transistor ,channel release ,isotropic dry etch ,high selectivity ,Chemistry ,QD1-999 - Abstract
The effect of the source/drain compressive stress on the mechanical stability of stacked Si nanosheets (NS) during the process of channel release has been investigated. The stress of the nanosheets in the stacking direction increased first and then decreased during the process of channel release by technology computer-aided design (TCAD) simulation. The finite element simulation showed that the stress caused serious deformation of the nanosheets, which was also confirmed by the experiment. This study proposed a novel channel release process that utilized multi-step etching to remove the sacrificial SiGe layers instead of conventional single-step etching. By gradually releasing the stress of the SiGe layer on the nanosheets, the stress difference in the stacking direction before and after the last step of etching was significantly reduced, thus achieving equally spaced stacked nanosheets. In addition, the plasma-free oxidation treatment was introduced in the multi-step etching process to realize an outstanding selectivity of 168:1 for Si0.7Ge0.3 versus Si. The proposed novel process could realize the channel release of nanosheets with a multi-width from 30 nm to 80 nm with little Si loss, unlocking the full potential of gate-all-around (GAA) technology for digital, analog, and radio-frequency (RF) circuit applications.
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- 2023
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6. Investigation of Nonlinear Flow in Discrete Fracture Networks Using an Improved Hydro-Mechanical Coupling Model
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Qun Sui, Weizhong Chen, and Luyu Wang
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nonlinear flow ,discrete fractured network ,stress ,rock ,excavation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Fractures commonly exist in rock masses; the coalescence of fractures provides fluid flow pathways in a fractured rock mass and greatly increases the flow capacity of fractured rock. This work aims to study the characteristics of nonlinear flow in fractures. A series of tests were conducted and indicated that the Forchheimer law performed well when describing the nonlinear relationship between hydraulic gradient and flow. The test results also indicate that higher water pressure may induce stronger nonlinearity. Additionally, the linear and nonlinear coefficients of the Forchheimer law increase with a decrease in the particle size of the filling material in fractures. On the basis of the laboratory results, the classical Forchheimer law was modified by considering the influence of stress on the variation of fracture aperture. A hydro-mechanical coupling model for fractured rock masses was built and programmed with a subroutine through ABAQUS. Furthermore, a random discrete fracture network was generated and simulated to prove that a high flow velocity will result in a nonlinear flow, not only in a single fracture, but also in a fracture network. The numerical results from fractured rock masses show that a ratio of the flow to the hydraulc gradient will change the flow from linear to weak nonlinearity and, finally, to strong nonlinearity with an increase in the hydraulic gradient. It also shows that the linear and nonlinear coefficients increase with an increase in the confining pressure and that they decrease with an increase in the aperture. Due to the complexity of fracture channels, a nonlinear flow is likely to occur in a fractured rock mass. Finally, the developed model was applied to simulate the flow behavior of underground engineering; the results show that the smaller the hydraulic aperture is, the higher the water pressure is required to be in order to change the flow regime from linear to nonlinear.
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- 2022
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7. Superhydrophobic Polymerized n‑Octadecylsilane Surface for BTEX Sensing and Stable Toluene/Water Selective Detection Based on QCM Sensor
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Luyu Wang, Xiaoli Cha, Yunling Wu, Jin Xu, Zhixuan Cheng, Qun Xiang, and Jiaqiang Xu
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Chemistry ,QD1-999 - Published
- 2018
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8. Analysis of Local Damages Effect on Mechanical Responses of Underwater Shield Tunnel via Field Testing and Numerical Simulation
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Xuyan Tan, Weizhong Chen, Luyu Wang, and Jianping Yang
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underground structure ,mechanical response ,damage ,nondestructive testing ,numerical simulation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The investigation of concrete structural performance is crucial to maintain the stability of infrastructure. In order to assess structural stability, this work focuses on the development of an integrated framework to detect damaged conditions in the field and analyze their effect on mechanical performance through nondestructive testing (NDT) technology and numerical models. First, a ground penetrating radar (GPR) and an infrared camera work collaboratively to identify the damaged positions of the concrete structure, with parameters calibrated by laboratory experiments. Then, a finite element model is established to study structural mechanical performance based on field conditions and detected results. In addition, the influenced regions induced by local damage are studied under different boundary conditions. As a case study, the devised method was employed in the Nanjing Yangtze River tunnel for stability assessment and disaster prevention. The detected results of the damaged conditions agree well with the actual conditions in the field. Numerical results show that the circumferential stress component is more significant than that observed longitudinally. The effect of local damage on stress implies a positive correlation with the rise of water pressure, in which the maximum stress response to the variation of water level is 45KPa per meter.
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- 2020
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9. Effects of Fe3O4 nanoparticles on anaerobic digestion enzymes and microbial community of sludge
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Jianbo Liu, Jin Wang, Lei Gong, Jun Zhou, You Xiaogang, Ying Zhou, Xiaoqi Yang, Tong Zuo, Haonan Zhang, Luyu Wang, and Qinwei Jia
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chemistry.chemical_classification ,Protease ,biology ,Chemistry ,Microorganism ,medicine.medical_treatment ,technology, industry, and agriculture ,Dehydrogenase ,General Medicine ,Cellulase ,Coenzyme F420 ,Anaerobic digestion ,Acetic acid ,chemistry.chemical_compound ,Enzyme ,biology.protein ,medicine ,Environmental Chemistry ,Food science ,Waste Management and Disposal ,Water Science and Technology - Abstract
Fe3O4 nanoparticles (NPs) have potential effects on the anaerobic digestion of excess sludge. The effects of different concentrations of Fe3O4 NPs (0, 100, 200, 400 and 600 mg/L) on enzymes and microorganisms in anaerobic digestion were studied to explore the mechanism of the effect of Fe3O4 NPs on anaerobic digestion. The results showed that 100, 200 and 400 mg/L Fe3O4 NPs could promote anaerobic digestion, and 200 mg/L Fe3O4 NPs had the most obvious promoting effect. The activities of protease, cellulase, dehydrogenase, acetic kinase and coenzyme F420 in the 200 mg/L Fe3O4 NPs group reached 120 U/mg VS, 71.75 U/g VS, 135 U/mL, 94 mol/L, 1.37 umol/g VSS, respectively, which were 3.8 times, 1.5 times, 1.2 times, 1.2 times and 1.6 times of the blank group, respectively. However, when the concentration of Fe3O4 NPs reached 600 mg/L, the activities of cellulase, dehydrogenase and acetic kinase were lower than those of the blank group, and anaerobic digestion was inhibited. The above conclusions can also be confirmed by high-throughput sequencing. The abundance of longilinea and ornatilina in the 200 mg/L Fe3O4 NPs group was 8.8% and 4.1% respectively, and methanthrix abundance was 69%, which was more conducive to decomposition acetic acid into CH4.
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- 2021
10. Effect of Fe3O4 nanoparticles on the performance of anaerobic digestion through electrochemical analysis
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Luyu Wang, Jianbo Liu, Jin Wang, Yi Qian, Xiaoqi Yang, Qinwei Jia, Haonan Zhang, Jun Zhou, Tong Zuo, Lei Gong, and Ying Zhou
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Chemistry ,0208 environmental biotechnology ,technology, industry, and agriculture ,Nanoparticle ,02 engineering and technology ,General Medicine ,Electrolyte ,010501 environmental sciences ,Electrochemistry ,01 natural sciences ,020801 environmental engineering ,chemistry.chemical_compound ,Anaerobic digestion ,Electrode ,Environmental Chemistry ,Waste Management and Disposal ,Anaerobic exercise ,Sodium acetate ,health care economics and organizations ,0105 earth and related environmental sciences ,Water Science and Technology ,Nuclear chemistry ,Graphite electrode - Abstract
In view of the high cost and complex operation of the traditional chemical method for the determination of the anaerobic digestion (AD) process, this study investigated the feasibility of using electrochemistry analysis to determine the effect of Fe3O4 nanoparticles (NPs) on the AD process. The quantity of electric charge of Fe3O4 NPs modified graphite electrode in sodium acetate electrolyte was higher than that of graphite electrode. The addition of Fe3O4 NPs was beneficial to improve the electrochemical activity of the electrode. On this basis, enzymes and microorganisms were extracted from anaerobic reactors containing different concentrations of Fe3O4 NPs to make electrodes respectively to further investigate the effects of Fe3O4 NPs on enzyme and microbial activities in AD. The electrochemical analysis results of the enzyme electrodes and microbial electrodes showed that the quantity of electric charge produced by the group of 200 mg/L Fe3O4 NPs was the highest. The cumulative biogas production of 200 mg/L Fe3O4 NPs was 809 mL/g VS, and better than other groups. These results showed that 200 mg/L Fe3O4 NPs was the best dosage, and the electrochemical analysis has higher sensitivity in the AD detection.
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- 2021
11. Hydroxyapatite nanorods: a nanobiomaterial for chemical detection of aniline vapor
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Yunling Wu, Jia Song, Luyu Wang, and Bing Wang
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chemistry.chemical_compound ,Materials science ,Aniline ,Chemical engineering ,chemistry ,Xylene ,Nanorod ,General Chemistry ,Quartz crystal microbalance ,BTEX ,Benzene ,Toluene ,Ethylbenzene - Abstract
Selective chemical detection of aniline vapor from benzene, toluene, ethylbenzene, and xylene (BTEX) is still a challenge. Here, we deliberately design a hydroxyapatite (HAP) nanorods nanobiomaterial modifying on the quartz crystal microbalance transducer for highly efficient detection of aniline from aniline/BTEX mixture. Besides, at room temperature, HAP nanorods perform excellent sensitivity of aniline, and the corresponding detection limit can reach down to 5 part per billion (ppb). The stability of HAP nanorods in the sensing process is also satisfactory. The sensing mechanism, as unveiled by the theoretical basis and the enthalpy extraction experiment, is due to the moderate acid–base absorptive interaction between aniline molecule and the HAP structure. The molecular formula of hydrate C6H7N·βH2O existing in wet air (with 50–90% relative humidity) can be obtained as C6H7N·1.36∼1.93H2O based on quantitatively measurement data.
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- 2021
12. Dual-enzymatically cross-linked gelatin hydrogel enhances neural differentiation of human umbilical cord mesenchymal stem cells and functional recovery in experimental murine spinal cord injury
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Junni Zhang, Fangxia Guan, Feng Gao, Minghao Yao, Luyu Wang, Shanshan Ma, and Jinrui Li
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food.ingredient ,Biomedical Engineering ,02 engineering and technology ,Gelatin ,Umbilical Cord ,Mice ,03 medical and health sciences ,0302 clinical medicine ,food ,Tissue engineering ,Animals ,Humans ,General Materials Science ,Spinal Cord Injuries ,Chemistry ,Regeneration (biology) ,Mesenchymal stem cell ,Neurogenesis ,Hydrogels ,Mesenchymal Stem Cells ,General Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,Cell biology ,Transplantation ,Self-healing hydrogels ,Stem cell ,0210 nano-technology ,030217 neurology & neurosurgery - Abstract
Recently, an advanced stem cell and tissue engineering approach has been recognized as an emerging and fascinating strategy to promote neural repair in spinal cord injury (SCI). Hydrogels can be properly engineered to encapsulate cells, enhance cell viability and neural differentiation, and provide the advantage of flexible adaptation to irregular defects. In this study, a dual-enzymatically cross-linked gelatin hydrogel with hydrogen horseradish peroxidase (HRP) and galactose oxidase (GalOx) was proposed to combine human umbilical cord mesenchymal stem cells (hUC-MSCs) for facilitating nerve regeneration post-SCI. In vitro, hUC-MSCs in this 3D gelatin hydrogel displayed good viability, proliferation, and neuronal differentiation. To further evaluate the neural regeneration effect of hUC-MSCs loaded into gelatin hydrogels in vivo, a clinically-relevant and force-controlled contusion model of mouse spinal cords was established. We found that implantation of a hydrogel loaded with hUC-MSCs significantly promoted the motor function recovery evaluated by Basso Mouse Scale (BMS) and footprint tests. Further histological analysis showed that the hydrogel and hUC-MSC combined transplantation dramatically decreased inflammation, inhibited apoptosis and promoted neurogenesis. Overall, implantation of this dual-enzymatically cross-linked and MSC-laden 3D gelatin hydrogel is a promising therapeutic strategy for SCI treatment.
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- 2021
13. In situ growth of MoS2 on three-dimensional porous carbon for sensitive electrochemical determination of bisphenol A
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Yanlong Feng, Feng Ye, Manli Guo, Ying Yu, Luyu Wang, Fuyue Wang, Lei Yanming, and Yujuan Cao
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Detection limit ,Nanocomposite ,Materials science ,General Chemical Engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,Electrode ,Materials Chemistry ,Differential pulse voltammetry ,0210 nano-technology ,Molybdenum disulfide ,Wet chemistry - Abstract
Three-dimensional porous carbon network (3D-C) was used as the substrate for the in situ growth of molybdenum disulfide (MoS2) through a wet chemistry method. The obtained 3D-C@MoS2 nanocomposite exhibited a porous structure, high surface area and good electrical conductivity. By using the 3D-C@MoS2 nanocomposite as a novel electrode modifier, the electrochemical oxidation peak current of bisphenol A (BPA) was greatly enhanced with a lowered background current. The improved sensitivity benefits from adsorption of BPA onto MoS2 surface, the large surface area and good conductivity of the 3D-C@MoS2 nanohybrid. By using differential pulse voltammetry (DPV), we observed a good linearity with BPA levels in the range of 0.001–10 μM, with a detection limit estimated to be 0.5 nM (S/N = 3). The 3D-C@MoS2 modified electrode could be reused for several times in spite of the accumulation of BPA, and the fabrication reproducibility is excellent. The prepared 3D-C@MoS2 modified electrode showed higher selectivity to BPA than several other phenolic compounds due to their different electrochemical oxidation potentials and the enhanced accumulation property of BPA at the 3D-C@MoS2 surface. The BPA contents in plastic product and environmental water samples were determined with the proposed method.
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- 2020
14. One-Pot Synthesis of Benzimidazo[2,1-b]thiazoline Derivatives through an Addition/Cyclization/Oxidative Coupling Reaction
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Xin Lv, Honglan Kang, Haofeng Wang, Guodong Shen, Tao Tong, Erfei Li, Jian-Wu Xie, Xin Wu, Luyu Wang, and Xiaoyu Li
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chemistry.chemical_compound ,chemistry ,Thiazoline ,Intramolecular force ,Organic Chemistry ,One-pot synthesis ,Surface modification ,Oxidative coupling of methane ,Combinatorial chemistry - Abstract
A novel and efficient approach to the synthesis of benzimidazo[2,1-b]thiazoline derivatives has been developed through an addition/cyclization/intramolecular oxidative C–H functionalization process...
- Published
- 2020
15. Graphene Oxide/Carbon Nanocoil Composite for High‐performance Humidity Sensor
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Luyu Wang, Junkuo Gao, Jinguli Wen, and Yuhang Wu
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Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Graphene ,law ,Composite number ,Oxide ,chemistry.chemical_element ,Humidity ,Carbon ,law.invention - Published
- 2020
16. Superhydrophobic hierarchical porous divinylbenzene polymer for BTEX sensing and toluene/water selective detection
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Luyu Wang, Shen Bing, Jiaqiang Xu, Jiawei Kong, and Yang Chen
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chemistry.chemical_classification ,Materials science ,Xylene ,02 engineering and technology ,General Chemistry ,BTEX ,Quartz crystal microbalance ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Divinylbenzene ,01 natural sciences ,Toluene ,Ethylbenzene ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,0210 nano-technology ,Benzene - Abstract
This work reports a superhydrophobic divinylbenzene polymer with hierarchical porous structure as sensing material to modify the quartz crystal microbalance (QCM) to detect benzene, toluene, ethylbenzene, and xylene (BTEX) vapor. Notably, sensing results toward toluene vapor in different relative humidities indicates that this superhydrophobic polymer has favorable toluene/water selective detection performance. Besides, the limit of detection toward toluene is lower than 1 ppm.
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- 2020
17. One-pot synthesis of 2-azolylimidazole derivatives through a domino addition/A3 coupling/cyclization process under copper catalysis
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Xiaoyu Li, Guodong Shen, Haofeng Wang, Luyu Wang, Honglan Kang, Erfei Li, Xin Lv, Xin Wu, Yifan Lin, and Liejin Zhou
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Quinazoline derivatives ,Organic Chemistry ,One-pot synthesis ,chemistry.chemical_element ,Biochemistry ,Copper ,Combinatorial chemistry ,Domino ,Catalysis ,Coupling (electronics) ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Physical and Theoretical Chemistry ,Paraformaldehyde - Abstract
A novel one-pot approach for the synthesis of multi-substituted 2-imidazolylimidazoles, 2-pyrazolylimidazoles and 2-indazolylimidazoles was developed through a domino addition/A3 coupling/cyclization process under copper catalysis. A variety of aminoethyl- or hydroxylethyl-tethered 2-azolylimidazole derivatives were conveniently and efficiently assembled in one pot using N-propargylcarbodiimides, azoles, paraformaldehyde and secondary amines as starting materials. The products containing an o-iodoaryl group could be further converted to imidazo[1,2-c]imidazo[1,2-a]quinazoline derivatives through a copper-catalyzed intramolecular C-H arylation.
- Published
- 2020
18. Impact of Ballast Fouling on the Mechanical Properties of Railway Ballast: Insights from Discrete Element Analysis
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Luyu Wang, Hani S. Mitri, and Mohamed A. Meguid
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Ballast ,Materials science ,0211 other engineering and technologies ,Modulus ,Bioengineering ,02 engineering and technology ,TP1-1185 ,Shear strength (soil) ,021105 building & construction ,micro-mechanical parameters ,medicine ,Chemical Engineering (miscellaneous) ,railway ballast fouling ,ballast degradation ,Geotechnical engineering ,shear strength ,QD1-999 ,021101 geological & geomatics engineering ,Fouling ,Process Chemistry and Technology ,Chemical technology ,Stiffness ,Shear (sheet metal) ,Chemistry ,Particle ,Direct shear test ,medicine.symptom - Abstract
Ballast fouling is a major factor that contributes to the reduction of shear strength of railway ballast, which can further affect the stability of railway supporting structure. The major sources of ballast fouling include infiltration of foreign fines into the ballast material and ballast degradation induced by train movement on the supported tracks. In this paper, a discrete element model is developed and used to simulate the shear stress–strain response of fouled ballast assembly subjected to direct shear loading. A simplified computational approach is then proposed to model the induced ballast fouling and capture the mechanical response of the ballast at various levels of contamination. The approach is based on the assumption that fine particles comprising the fouling material will not only change the interparticle friction angle, but also the contact stiffness between the ballast particles. Therefore, both the interparticle friction coefficient and effective modulus are adjusted based on a fouled ballast model that is validated using experimental results. The effect of ballast degradation is also investigated by gradually changing the particle size distribution of the ballast assembly in the discrete element model to account for the increased range of particle sizes. Using the developed model, the effect of ballast degradation on the shear strength is then evaluated. Conclusions are made to highlight the suitability of these approximate approaches in efficiently modeling ballast assemblies under shear loading conditions.
- Published
- 2021
19. La doped AlPO-5: Enhenced NH3 sensing properties, thermodynamic investigation and humidity-enhanced effect
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Luyu Wang, Jia Song, Yunling Wu, and Junkuo Gao
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Work (thermodynamics) ,Materials science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Inorganic Chemistry ,Ammonia ,chemistry.chemical_compound ,law ,Materials Chemistry ,Calcination ,Physical and Theoretical Chemistry ,Crystallization ,Doping ,Humidity ,Quartz crystal microbalance ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,Chemical engineering ,Ceramics and Composites ,0210 nano-technology ,Selectivity - Abstract
Solid AlPO-5 and La doped AlPO-5 (La/AlPO-5) were synthesized by a hydrothermal treatment followed by crystallization and calcination. The ammonia (NH3) sensing properties of AlPO-5 and La/AlPO-5 were evaluated by using quartz crystal microbalance (QCM) platform to work out the enhanced effect of La doping treatment. La/AlPO-5 possessed a higher response to NH3 than that of AlPO-5 with same concentration. In addition to the favorable sensitivity, La/AlPO-5 based sensor also showed prominent repeatability and selectivity. We also explored the thermodynamics and humidity-enhanced effect in the NH3 sensing process.
- Published
- 2019
20. Photoreceptors in a mouse model of Leigh syndrome are capable of normal light-evoked signaling
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Mikael Klingeborn, Amanda M. Travis, Vadim Y. Arshavsky, Alexander V. Kolesnikov, Luyu Wang, Sidney M. Gospe, and Vladimir J. Kefalov
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0301 basic medicine ,Light Signal Transduction ,genetic structures ,Mitochondrial disease ,Biology ,Biochemistry ,Retinal ganglion ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Neurobiology ,Electroretinography ,medicine ,Animals ,Humans ,Molecular Biology ,Mice, Knockout ,Retina ,Electron Transport Complex I ,Retinal pigment epithelium ,030102 biochemistry & molecular biology ,medicine.diagnostic_test ,Retinal Degeneration ,NDUFS4 ,Retinal ,Cell Biology ,medicine.disease ,eye diseases ,Cell biology ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,sense organs ,Leigh Disease ,Photoreceptor Cells, Vertebrate ,Visual phototransduction - Abstract
Mitochondrial dysfunction is an important cause of heritable vision loss. Mutations affecting mitochondrial bioenergetics may lead to isolated vision loss or life-threatening systemic disease, depending on a mutation's severity. Primary optic nerve atrophy resulting from death of retinal ganglion cells is the most prominent ocular manifestation of mitochondrial disease. However, dysfunction of other retinal cell types has also been described, sometimes leading to a loss of photoreceptors and retinal pigment epithelium that manifests clinically as pigmentary retinopathy. A popular mouse model of mitochondrial disease that lacks NADH:ubiquinone oxidoreductase subunit S4 (NDUFS4), a subunit of mitochondrial complex I, phenocopies many traits of the human disease Leigh syndrome, including the development of optic atrophy. It has also been reported that ndufs4(−/−) mice display diminished light responses at the level of photoreceptors or bipolar cells. By conducting electroretinography (ERG) recordings in live ndufs4(−/−) mice, we now demonstrate that this defect occurs at the level of retinal photoreceptors. We found that this deficit does not arise from retinal developmental anomalies, photoreceptor degeneration, or impaired regeneration of visual pigment. Strikingly, the impairment of ndufs4(−/−) photoreceptor function was not observed in ex vivo ERG recordings from isolated retinas, indicating that photoreceptors with complex I deficiency are intrinsically capable of normal signaling. The difference in electrophysiological phenotypes in vivo and ex vivo suggests that the energy deprivation associated with severe mitochondrial impairment in the outer retina renders ndufs4(−/−) photoreceptors unable to maintain the homeostatic conditions required to operate at their normal capacity.
- Published
- 2019
21. QCM formaldehyde sensing materials: Design and sensing mechanism
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Luyu Wang, Junkuo Gao, and Jiaqiang Xu
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Gaseous formaldehyde ,Materials science ,Metals and Alloys ,Formaldehyde ,Nanotechnology ,02 engineering and technology ,Quartz crystal microbalance ,Materials design ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Electrochemical gas sensor ,chemistry.chemical_compound ,Low energy ,chemistry ,Materials Chemistry ,Surface acoustic wave sensor ,Electrical and Electronic Engineering ,Semiconductor sensor ,0210 nano-technology ,Instrumentation - Abstract
Gaseous formaldehyde (HCHO) sensing is indispensable because HCHO is hazardous to health and widely exists in newly decorated house and newly painted furniture. Multitudinous HCHO sensors based on various platforms, such as semiconductor sensor, electrochemical sensor, surface acoustic wave sensor (SAW), fluorescent sensor, have been fabricated over the last few years. Except these sensors, quartz crystal microbalance (QCM) sensors have received increasing attention because of their high sensitivity, convenient operation, low energy consumption, and excellent modifiable property. Recently, based on QCM, many efforts have been made to design chemical sensing materials to detect HCHO gas sensitively and selectively. In this review, we summary the scientific researches of gaseous HCHO detection based on QCM platform, and introduce the related works of sensing HCHO carried out by our group as well as the exploration of sensing mechanism.
- Published
- 2019
22. Facile preparation of N-rich functional polymer with porous framework as QCM sensing material for rapid humidity detection
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Xiaohong Wang, Jiaqiang Xu, Jin Xu, Zhixuan Cheng, and Luyu Wang
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Materials science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Materials Chemistry ,Deposition (phase transition) ,Molecule ,Relative humidity ,Electrical and Electronic Engineering ,Porosity ,Instrumentation ,chemistry.chemical_classification ,Polypropylene ,Metals and Alloys ,Humidity ,Polymer ,Quartz crystal microbalance ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Chemical engineering ,0210 nano-technology - Abstract
Although many humidity sensing materials have satisfactory properties based on quartz crystal microbalance (QCM) transducer, their synthesis processes are complex. Herein, we report an effective and facile method to modify porous polypropylene microfiltration membrane (PPMM) evenly via the deposition of N-rich functional polymer (PDA-PEI), which was easily synthesized by crosslinking polydopamine (PDA) and polyethyleneimine (PEI). The PDA-PEI modified PPMM well retained the pore structure and was first employed to detect relative humidity based on QCM featured with rapid response, satisfactory repeatability and stability. Compared with PDA modified PPMM, the humidity sensing performance of PDA-PEI modified PPMM is improved considerably. Furthermore, the sensing mechanism study based on Gaussian 09 software reveals that the interaction between PDA-PEI and water molecules belongs to weak chemical adsorption. Such a comprehensive research foresees the potential application of PDA-PEI modified PPMM for fast detection of humidity indoor and outdoor.
- Published
- 2019
23. Dual-enzymatically crosslinked and injectable hyaluronic acid hydrogels for potential application in tissue engineering
- Author
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Luyu Wang, Junni Zhang, Dan Zhang, Feng Gao, Shanshan Ma, Fangxia Guan, Minghao Yao, and Jinrui Li
- Subjects
biology ,General Chemical Engineering ,Regeneration (biology) ,General Chemistry ,Horseradish peroxidase ,chemistry.chemical_compound ,chemistry ,Tissue engineering ,In vivo ,Hyaluronic acid ,Drug delivery ,Self-healing hydrogels ,biology.protein ,Cytotoxicity ,Biomedical engineering - Abstract
Recently, in situ formed injectable hydrogels have shown great potential in biomedical applications as therapeutic implants or carriers in tissue repair and regeneration. They can seal or fill the damaged tissue to function as cell/drug delivery vehicle perfectly through a minimally invasive surgical procedure. In this study, hyaluronic acid (HA) is functionalized with tyramine to produce an injectable hydrogel dual-enzymatically crosslinked by horseradish peroxidase (HRP) and galactose oxidase (GalOX). This new tyramine-modified HA (HT) hydrogel exhibited good injectability, favorable cytocompatibility to mice bone marrow mesenchymal stem cells (BMSCs), and low inflammatory response verified by cytotoxicity assay in vitro and an in situ subcutaneous injection study in vivo. In addition, the gelation time, swelling behavior, and degradation rate of the HT hydrogel could be adjusted through varying the concentrations of HT and GalOX in a certain range. These encouraging results suggest that such biocompatible HT hydrogels might have potential application in three-dimensional stem cell culture and tissue engineering.
- Published
- 2019
24. A 3D Calcium Spirobifluorene Metal–Organic Framework: Single-Crystal-to-Single-Crystal Transformation and Toluene Detection by a Quartz Crystal Microbalance Sensor
- Author
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Zhiming Duan, Xueting Fang, Xiang He, Jiaqiang Xu, and Luyu Wang
- Subjects
chemistry.chemical_element ,02 engineering and technology ,Quartz crystal microbalance ,Calcium ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Co2 adsorption ,01 natural sciences ,Toluene ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Physical chemistry ,Metal-organic framework ,Physical and Theoretical Chemistry ,0210 nano-technology ,Porosity ,Single crystal ,Shrinkage - Abstract
A new 3D metal–organic framework Ca-SBF based on a zigzag-shaped tetranuclear calcium oxocluster and 9,9′-spirobi[9H-fluorene]-2,2′,7,7′-tetracarboxylic acid was obtained and exhibited flu topology. Ca-SBF underwent a single-crystal-to-single-crystal transformation to form Ca-SBF-1 with a slight structure shrinkage. Activated Ca-SBF showed permanent porosity and CO2 adsorption properties. A Ca-SBF-modified quartz crystal microbalance sensor demonstrated selective response to toluene vapor.
- Published
- 2018
25. PODS-covered PDA film based formaldehyde sensor for avoiding humidity false response
- Author
-
Zhixuan Cheng, Luyu Wang, Jin Xu, Jiaqiang Xu, Yongpeng Yu, and Qun Xiang
- Subjects
Materials science ,Environmental humidity ,Metals and Alloys ,Formaldehyde ,Humidity ,Nanotechnology ,02 engineering and technology ,Quartz crystal microbalance ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Electrical and Electronic Engineering ,Composite material ,0210 nano-technology ,Instrumentation - Abstract
To avoid false response caused by increase of environmental humidity is important for hydrophilic polydopamine (PDA) based QCM formaldehyde sensor. In order to achieve this purpose, superhydrophobic polymerized n -octadecylsiloxane (PODS) nanostructure is used to cover the surface of PDA film to prevent false response from happening. Compared with pristine PDA based QCM sensor, the sensor based on PODS-PDA composite sensing material shows satisfactory performance on avoiding false response and long-term stable formaldehyde sensing properties. This novel strategy offers a new method to reduce probability of false response resulted from humidity change.
- Published
- 2018
26. Antiferromagnetic Copper(II) Metal–Organic Framework Based Quartz Crystal Microbalance Sensor for Humidity
- Author
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Zhuoqiang Zhou, Xiang He, Luyu Wang, Zhao-Xi Wang, Ming-Xing Li, and Tao Chi
- Subjects
Diffraction ,Analytical chemistry ,chemistry.chemical_element ,Infrared spectroscopy ,02 engineering and technology ,General Chemistry ,Quartz crystal microbalance ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Copper ,Dimethylacetamide ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Antiferromagnetism ,General Materials Science ,Metal-organic framework ,Relative humidity ,0210 nano-technology - Abstract
A novel copper metal–organic framework (MOF) [Cu3L2(H2O)2.75]·0.75H2O·1.75DMA (H3L = 4-(2-carboxyphenoxy)-isophthalic acid, DMA = dimethylacetamide) has been synthesized and structurally characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 shows a three-dimensional architecture with a sqc topology net where the [Cu2(COO)4] unit was viewed as a node. Magnetic studies indicate that strong antiferromagnetic coupling with J = −159.0(9) cm–1 dominates in the compound. As a sensor, the compound based on quartz crystal microbalance (QCM) exhibits good linearity humidity sensing properties after being exposed to various relative humidity environments at room temperature. The resulting sensitivity is about 28.7 Hz/%RH with a good linearity coefficient of 0.993.
- Published
- 2017
27. One novel humidity-resistance formaldehyde molecular probe based hydrophobic diphenyl sulfone urea dry-gel: Synthesis, sensing performance and mechanism
- Author
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Zhixuan Cheng, Yang Chen, Luyu Wang, Qun Xiang, Ye Zhu, and Jiaqiang Xu
- Subjects
chemistry.chemical_classification ,Diphenyl sulfone ,Inorganic chemistry ,Metals and Alloys ,Formaldehyde ,02 engineering and technology ,Quartz crystal microbalance ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Aldehyde ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Adsorption ,chemistry ,Materials Chemistry ,Urea ,Amine gas treating ,Electrical and Electronic Engineering ,0210 nano-technology ,Instrumentation ,Tetrahydrofuran - Abstract
The work designs a novel hydrophobic organic dry-gel named diamino diphenyl sulfone (DDS) urea for selectively detecting formaldehyde in air. It is synthesized by using octadecylisothiocyanate and diamino diphenyl sulfone as reactants in tetrahydrofuran solution at 70 °C. The dry-gel is obtained by freezing drying. Sulfanilamide urea dry-gel acts as the contrastive material which is synthesized in a similar condition. The dry-gel coated Quartz Crystal Microbalance (QCM) sensor exhibits a rapid and reversible selective response towards formaldehyde gas. Repeated measurement results show high sensitivity and low detection limit (1 ppm) for formaldehyde detection. The gas sensing and contact angle tests indicate its stability under different humidity conditions. Based on the adsorption isotherm experiments, it reveals that adsorption enthalpy change between DDS urea dry-gel and HCHO molecules locates the range of chemical adsorption, endowing the sensor satisfactory selectivity and reversibility. Sensing mechanism of formaldehyde sensor has been proved by a simulation calculation based on a quantum chemistry software Gaussian though comparing the interaction between amine group or carbamido and formaldehyde. The calculation results reveal that Schiff base interaction between the amine group and aldehyde group is more responsible for formaldehyde sensing instead of hydrogen bond interaction between carbamido and aldehyde group.
- Published
- 2017
28. A NiCo2 O4 Shell on a Hollow Ni Nanorod Array Core for Water Splitting with Enhanced Electrocatalytic Performance
- Author
-
Jialei Zhang, Luyu Wang, Changdong Gu, Xiang Ge, Jiangping Tu, and Hongyi Zhu
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Oxygen evolution ,Energy Engineering and Power Technology ,Nanotechnology ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Bifunctional catalyst ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Electrode ,Materials Chemistry ,Water splitting ,Nanorod ,0210 nano-technology ,Bifunctional - Abstract
Nickel cobaltite (NiCo2O4) nanostructures have been considered as promising bifunctional electrocatalyst materials for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte. However, the activity of these materials toward overall water splitting is still unsatisfactory because a larger voltage is needed to drive the reactions. This study shows that more-efficient bifunctional catalysts based on NiCo2O4 materials can be obtained by adopting an integrated composite electrode with robust hollow structures. This novel electrode is constructed by the growth of hollow Ni@NiCo2O4 nanorod arrays on three-dimensional (3D) Ni foam. The interlayer of Ni hollow nanorods is conformally covered by NiCo2O4 nanosheets, providing large surface area and fast electron transport. Benefiting from these integrated characteristics, the hollow Ni@NiCo2O4 electrode as an oxygen evolution electrocatalyst can deliver a low overpotential of 270 mV at 10 mA cm−2 and present excellent electrochemical durability. Meanwhile, the HER performance also impressive, with an overpotential of about 87 mV at 10 mA cm−2. As a result, the hollow Ni@NiCo2O4 electrode as a bifunctional catalyst can achieve a current density of 10 mA cm−2 with a voltage of only 1.58 V, showing promise for high performance yet cheap electrocatalysts for the overall water splitting reactions.
- Published
- 2017
29. Endogenous bioactive compounds of naked oats (Avena nuda L.) inhibit α-amylase and α-glucosidase activity
- Author
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Xuanxuan Cheng, Yanwen Wu, Luyu Wang, Jie Ouyang, Mengjie Wei, and Minyue Tang
- Subjects
0106 biological sciences ,chemistry.chemical_classification ,biology ,Chemistry ,Saponin ,Endogeny ,Mixed inhibition ,04 agricultural and veterinary sciences ,biology.organism_classification ,Inhibitory postsynaptic potential ,040401 food science ,01 natural sciences ,Ferulic acid ,chemistry.chemical_compound ,Hydrolysis ,0404 agricultural biotechnology ,Biochemistry ,010608 biotechnology ,biology.protein ,Avena nuda ,Amylase ,Food Science - Abstract
This study aims to investigate the inhibitory effects of free and bound bioactive extracts from naked oat on amylase and glucosidase activity. The free compound extract mainly included kaempferol-3-O-galactoside-6″-rhamnoside-3‴-rha, hesperetin-7-O-neohesperidoside, ginsenoside Re and soyasaponin Ba. Ten substances were detected in the bound compound extract, including ferulic acid, oxyacanthine, and trans-4-coumaric acid. The free and bound compound extracts showed dose-dependent inhibitory effects on α-amylase and α-glucosidase; the inhibition of α-amylase was reversible anti-competitive inhibition, and the inhibition of α-glucosidase was reversible linear mixed inhibition. The saponin ginsenoside Re had poor inhibitory effects on α-amylase and α-glucosidase; the saponin soyasaponin Ba had a poor inhibitory effect on α-amylase but a good inhibitory effect on α-glucosidase. After adding the extracts to the different starches, the hydrolysis rates all decreased significantly (p
- Published
- 2021
30. High performance formaldehyde detection based on a novel copper (II) complex functionalized QCM gas sensor
- Author
-
Jiaqiang Xu, Qun Xiang, Zhaoxi Wang, Luyu Wang, Zhiming Duan, and Yang Chen
- Subjects
Inorganic chemistry ,Analytical chemistry ,Formaldehyde ,chemistry.chemical_element ,Infrared spectroscopy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Materials Chemistry ,Molecule ,Electrical and Electronic Engineering ,Instrumentation ,Detection limit ,Chemistry ,Metals and Alloys ,Quartz crystal microbalance ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Copper ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Physical vapor deposition ,Electrode ,0210 nano-technology - Abstract
In order to construct highly sensitive and stable QCM gas sensor, we present an innovative strategy. Firstly, we employ a physical vapor deposition (PVD) method to coat a thin layer of copper on the surface of QCM silver electrode. Then, a novel metal complex as sensing material, [Cu(DDS) 2 (Cl) 2 (MeOH) 2 ], is grown in-situ on the copper layer to ensure a strong coupling between metal complex sensing materials and QCM electrode. The sensing material is characterized through following instruments: elemental analysis, single crystal XRD, SEM, PXRD, IR spectra and TGA. The sensing test results indicate that the QCM sensor exhibit high sensitivity and selectivity toward gaseous formaldehyde because of a reversible interaction between amino group and HCHO molecule. The detection limit reaches down to 50 ppb. This implies the facile-fabricated sensor has a great potential in the area of rapid, stable, sensitive, and selective formaldehyde on-site detection. Based on the temperature-varying micro-gravimetric experiment, enthalpy change is quantitatively obtained, which indicates that the interaction between the complex and HCHO molecules belongs to chemical adsorption. The values of ΔH calculated by Gaussian 09 indicate that chemical adsorption between NH 2 group and aldehyde group play a leading role in detecting selectively formaldehyde gas.
- Published
- 2017
31. Non-starch constituents influence the in vitro digestibility of naked oat (Avena nuda L.) starch
- Author
-
Luyu Wang, Xuanxuan Cheng, Jie Ouyang, Yanwen Wu, and Minyue Tang
- Subjects
food.ingredient ,beta-Glucans ,Avena ,Starch ,Flour ,01 natural sciences ,Plant Proteins, Dietary ,Analytical Chemistry ,chemistry.chemical_compound ,Crystallinity ,0404 agricultural biotechnology ,food ,Food science ,Resistant starch ,biology ,fungi ,010401 analytical chemistry ,food and beverages ,04 agricultural and veterinary sciences ,General Medicine ,biology.organism_classification ,040401 food science ,Lipids ,In vitro ,0104 chemical sciences ,Glycemic index ,chemistry ,Solubility ,Glycemic Index ,Avena nuda ,Digestion ,Food Science - Abstract
The present study investigated the effects of proteins, lipids and β-glucan in naked oat flour (NOF) on the in vitro digestibility of starch. The content of rapidly digested starch (RDS) increased, and the content of resistant starch (RS) decreased in NOF after removing the non-starch constituents. The estimated glycemic index (eGI) of starch in NOF increased after the removal of the non-starch constituents, with a decreasing order of naked oat starch (NOS) > de-β-glucan flour > de-proteins flour > de-lipids flour > NOF. NOS was found to have an A-type crystalline pattern, but the removal of proteins or β-glucan rendered NOS a V-type crystalline pattern. The relative crystallinity decreased after removing non-starch constituents. The in vitro digestibility was positively correlated with the short-range molecular order and negatively correlated with the relative crystallinity. These results clearly illustrate the effects of non-starch constituents on the low digestibility of naked oat.
- Published
- 2019
32. Superhydrophobic n-octadecylsiloxane (PODS)-functionalized PDA-PEI film as efficient water-resistant sensor for ppb-level hexanal detection
- Author
-
Yunling Wu, Hui Xu, Gaojie Li, Junkuo Gao, Luyu Wang, and Qichun Zhang
- Subjects
Detection limit ,chemistry.chemical_classification ,Water resistant ,Materials science ,Hydrogen bond ,General Chemical Engineering ,Parts-per notation ,02 engineering and technology ,General Chemistry ,Quartz crystal microbalance ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Hexanal ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Copolymer ,Environmental Chemistry ,0210 nano-technology - Abstract
The detection of hexanal vapor in ppb (part per billion) concentration is an unresolved and indispensable issue. Here we report a polydopamine-polyethyleneimine (PDA-PEI) copolymer film with rich imino groups to sense 50 ppb hexanal vapor through the formation of the reversible hydrogen bonds with hexanal. We found that the water-resistance could be further improved by attaching superhydrophobic n-octadecylsiloxane (PODS) onto the surface of PDA-PEI film. The chemical adsorption mode and the core role of imino group for the hexanal detection have been validated by combining experiment methods with theory calculations. A quartz crystal microbalance (QCM) platform modified with this film was employed as a hexanal vapor sensor under ambient conditions, which possessed several advantages including the high response of 34.8 Hz to 250 ppb hexanal, low detection limit of 50 ppb hexanal at 25 °C, and good water-resistance.
- Published
- 2020
33. Enhanced NH3 sensing properties of carboxyl functionalized carbon nanocoil
- Author
-
Jia Song and Luyu Wang
- Subjects
Biomaterials ,Ammonia ,chemistry.chemical_compound ,Materials science ,Polymers and Plastics ,chemistry ,Chemical engineering ,Metals and Alloys ,chemistry.chemical_element ,Quartz crystal microbalance ,Carbon ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Based on Quartz Crystal Microbalance (QCM) sensing platform, modifying functional groups was usually used to improve the performance of sensing materials. In this work, we reported a novel sensing material, carboxyl functionalized carbon nanocoil by acidification treatment. It was found that carboxyl functionalized carbon nanocoil had excellent reversible response to ammonia (NH3), and the response to 50 ppm NH3 was as high as 8.1 Hz. As a contrast, pristine carbon nanocoil had only 2 Hz response to 50 ppm NH3. The enhanced response should be ascribed to the hydrogen bond adsorption between carboxyl gropus and NH3 molecules. These results demonstrated that carboxyl functionalization could improve the NH3 sensing performance of carbon nanocoil, which has potential in monitoring NH3 in the future.
- Published
- 2020
34. Dual-enzymatically crosslinked hyaluronic acid hydrogel as a long-time 3D stem cell culture system
- Author
-
Dan Zhang, Luyu Wang, Feng Gao, Fangxia Guan, Jinrui Li, Minghao Yao, and Junni Zhang
- Subjects
Scaffold ,Magnetic Resonance Spectroscopy ,Biocompatibility ,Cell Survival ,Polymers ,0206 medical engineering ,Cell Culture Techniques ,Biomedical Engineering ,Biocompatible Materials ,Bioengineering ,02 engineering and technology ,Regenerative Medicine ,Regenerative medicine ,Biomaterials ,3D cell culture ,chemistry.chemical_compound ,Tissue engineering ,Hyaluronic acid ,Humans ,Hyaluronic Acid ,Cells, Cultured ,Horseradish Peroxidase ,Tissue Engineering ,Tissue Scaffolds ,Chemistry ,Stem Cells ,Mesenchymal stem cell ,Hydrogels ,Mesenchymal Stem Cells ,021001 nanoscience & nanotechnology ,020601 biomedical engineering ,Cell biology ,Alcohol Oxidoreductases ,Microscopy, Fluorescence ,Stem cell ,0210 nano-technology - Abstract
Stem cell-based tissue engineering shows enormous potential for regenerative medicine. Three-dimensional (3D) stem cell culture is the most basic aspect of tissue engineering. However, achievement of a perfect scaffold for highly efficient 3D cell culture is currently still limited. Herein, a new hyaluronic acid hydrogel dual-enzymatically crosslinked by horseradish peroxidase and choline oxidase is developed as a 3D stem cell culture system. This hydrogel possesses superior stability over two months, controllable biodegradability with hyaluronidases, a high swelling ratio exceeding 6000%, and excellent cytocompatibility in vitro and biocompatibility in vivo. More importantly, a long-time and highly cellular activity 3D culture of bone marrow-derived mesenchymal stem cells was achieved in vitro over 20 days. All these encouraging results highlight the great potential of this new hydrogel for 3D culture and tissue engineering.
- Published
- 2020
35. Recent progress in metal-organic frameworks-based hydrogels and aerogels and their applications
- Author
-
Hui Xu, Qichun Zhang, Junkuo Gao, Luyu Wang, and Juming Yao
- Subjects
Supercapacitor ,010405 organic chemistry ,Graphene ,Chemistry ,Nanoparticle ,Nanotechnology ,Aerogel ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,law.invention ,Inorganic Chemistry ,law ,Self-healing hydrogels ,Materials Chemistry ,Metal-organic framework ,Physical and Theoretical Chemistry - Abstract
In recent years, metal-organic frameworks (MOFs) have attracted incredible chemical and material research interests because of their prominent properties and charming structures. The reliable production of a wide variety of MOFs materials and MOF derivatives, such as MOF-metal nanoparticles composites and MOFs-polymers hybrids, offers many possibilities to develop MOF-based applied materials. Although MOFs have many unique features, including abundant pore structures and multiple functional ligands, their applied performance is limited by intrinsic fragility and powdered crystalline state, as well as unsatisfied stability and processability. By this, MOF-based hydrogels and aerogels have achieved unparalleled results, outperforming ungelated MOFs materials in many aspects. This review presents current developments of MOF-based hydrogels and aerogels with emphasis on the specific categories and the synergistic effects of MOF-derived aerogels between MOFs and additional materials. Particular emphasis is placed on discussing the advantages of MOF-based hydrogels and aerogels in applications such as sensors, batteries, supercapacitors, adsorbents, catalysts etc. MOF-based hydrogels and aerogels can provide valuable guidance for the investigation of MOFs towards practical applications with processability, stability, and easy handling. Specifically, we will summary recent progress of pure MOF hydrogels, MOF@biology derived organic macromolecules hydrogels, MOF@biocompatible hydrogels, MOF@ graphene hydrogels, pure MOF aerogels, MOF@silica aerogel composites, MOF@ graphene aerogel composites, MOF@cellulose aerogel composites, and aerogel composites containing MOFs-derived materials. In addition, their applications are also discussed. We hope that this review will be helpful for those who want quick access to valuable references about MOF-based hydrogels and aerogels and their applications.
- Published
- 2019
36. Functionalized N-Doped Porous Carbon Nanofiber Webs for a Lithium–Sulfur Battery with High Capacity and Rate Performance
- Author
-
Songcan Wang, Juan Yang, Jingjing Tang, Xiangyang Zhou, Jing Xie, Youlan Zou, Luyu Wang, and Feng Chen
- Subjects
Battery (electricity) ,Materials science ,Composite number ,chemistry.chemical_element ,Lithium–sulfur battery ,Nanotechnology ,Polypyrrole ,Electrochemistry ,Sulfur ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,General Energy ,chemistry ,Chemical engineering ,Nanofiber ,Specific surface area ,Physical and Theoretical Chemistry - Abstract
Functionalized N-doped porous carbon nanofiber webs/sulfur (N-PCNF/S) composites are first proposed as the cathode materials for an advanced lithium–sulfur battery. The functionalized N-doped porous carbon nanofiber webs (N-PCNF) with an appropriate N doping (4.32 wt %) are synthesized by a facile approach, which consists of pyrolyzation of polypyrrole nanofiber and a subsequent KOH activation. Instrumental analysis shows that N-PCNF possesses a large specific surface area (2642 m2 g–1) and a high inner pore volume (1.31 cm3 g–1). When evaluating its electrochemical properties in a lithium–sulfur battery, the N-PCNF/S composite with 77.01 wt % sulfur content displays an excellent electrochemical performance. The specific discharge capacity still reaches 749.8 mAh g–1 after 180 cycles at 0.2 C. At a higher rate of 1 C, the capacity stabilizes at 666.0 mAh g–1 after 200 cycles. This work demonstrates that combining the favorable aspects of N doping modification and one-dimensional nanostructure in the carbo...
- Published
- 2014
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