31 results on '"Yuan, Qiang"'
Search Results
2. Effect of unidirectional temperature conduction on the strength evolution of shotcrete in a high geothermal environment.
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Yuan, Qiang, Xue, Kaiwei, Zhang, Suhui, Tian, Yi, Hu, Chaolong, and Liu, Xiao
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SHOTCRETE , *TEMPERATURE effect , *POROSITY , *TEMPERATURE distribution , *ETTRINGITE - Abstract
The high geothermal environment causes a temperature gradient inside shotcrete, which affects the development of its mechanical strength. This research investigated the strength evolution of shotcrete in simulated high geothermal environment by applying a unidirectional heat source. The influence of temperature gradient on the pore structure, morphology, phase composition, and hydration degree of shotcrete was also studied. It was found that the early strength of shotcrete was improved but that the later strength was reduced in the high geothermal environment. It was attributed to the increase in harmful porosity and total porosity of the concrete caused by the high-temperature curing. Cracks and pores can be observed in the microstructure near the heat source region. Besides, the ettringite content in shotcrete was lower than that under standard curing environment and presented gradient distribution in the direction of the temperature gradient. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Domperidone inhibits cell proliferation via targeting MEK and CDK4 in esophageal squamous cell carcinoma.
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Yuan, Qiang, Shi, Yunshu, Zhang, Yuhan, Shi, Yaqian, Hussain, Zubair, Zhao, Jimin, jiang, Yanan, Qiao, Yan, Guo, Yaping, Lu, Jing, Dong, Ziming, Dong, Zigang, Wang, Junyong, and Liu, Kangdong
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SQUAMOUS cell carcinoma , *INHIBITION of cellular proliferation , *DOMPERIDONE , *CYCLIN-dependent kinases , *GASTROINTESTINAL motility disorders - Abstract
Background: Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of digestive system tumor related death in the world. Unfortunately, effective chemopreventive agent is lack for patients with ESCC in clinical practice, which leads to the extremely high mortality rate. Methods: A library of prescribed drugs was screened for finding critical anti-tumor properties in ESCC cells. The phosphoproteomics, kinase array, pulldown assay and drug affinity responsive target stabilization assay (DARTS) were applied to explore mechanisms and searched for synergistic targets. Established models of PDX in mice were used to determine the therapeutic effect of domperidone. Results: After screening a library of prescribed drugs, we discovered that domperidone has anti-tumor properties. Domperidone, acting as a gastroprokinetic agent, has been widely used in clinic for gastrointestinal motility disorders. Despite limited research, there are indications that domperidone may have anti-tumor properties. In this study, we determined that domperidone significantly inhibited ESCC proliferation in vitro and in vivo. We employed phosphoproteomics to reveal p-ERK, and p-SMAD3 down-regulation upon domperidone treatment. Then, the results of kinase assay and pulldown assay further validated that domperidone directly combined with MEK1/2 and CDK4, leading to the inhibition of their kinase activity. Furthermore, our results revealed that MEK/ERK and CDK4/SMAD3 signal pathway were major pathways in domperidone against ESCC. Conclusion: Collectively, these findings suggest that domperidone serves as an effective "multi-target" inhibitor of MEK1/2 and CDK4, offering potential benefits for the chemoprevention of ESCC. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Investigation on deformation behavior and bearing capacity of a segmental ring based on the horizontal convergence.
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Yuan, Qiang, Zhao, Xu, Li, Yang, and Yuan, Bingxiang
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In this study, a refined numerical model, which contains the detailed geometric construction of the longitudinal joints, is established to investigate the bearing performance of the segmental ring based on the horizontal convergence. Firstly, the model is verified by comparing it with the reported results of a documented full‐scale model test. Then, according to the load‐structure method, this numerical model is employed to investigate the deformation behavior and bearing capacity of the segmental ring. Moreover, the effects of the coefficient of lateral pressure and subgrade reaction are extensively taken into consideration through comprehensive numerical analyses. According to the numerical results, a bilinear model is proposed to describe the relation between the convergent displacement and the stratum pressure, which could be used to preliminarily estimate the convergence after the completion of tunnel construction. Otherwise, the development of structural defects, such as the joint opening and the water leakage, has close association with the horizontal convergence. Therefore, a simple evaluation method for tunnel structure safety assessment is proposed using horizontal convergence deformation as an indicator to predict the tunnel service state. Since this indicator is easy to obtain during the tunnel operation, it is convenient for the engineers to assess the bearing capacity of the segmental ring and the service state of the tunnel structure quickly. [ABSTRACT FROM AUTHOR]
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- 2024
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5. PtCu/Pt core/atomic-layer shell hollow octahedra for oxygen reduction and methanol oxidation electrocatalysis.
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Zhou, Yi and Yuan, Qiang
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OXIDATION of methanol , *OXYGEN reduction , *PROTON exchange membrane fuel cells , *METHANOL as fuel , *OXIDATION-reduction reaction , *ELECTROCATALYSIS , *METHANOL , *OCTAHEDRA - Abstract
Engineering effective bifunctional electrocatalysts that outperform the benchmark Pt/C for direct methanol proton exchange membrane fuel cells is desired and challenging. Here, we designed H-PtCu/PtL OH catalysts with a sub-nanometer Pt(111) shell layer featuring Cu- and Co-vacancies, which exhibited high activity in acidic oxygen reduction and methanol oxidation reactions. [ABSTRACT FROM AUTHOR]
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- 2024
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6. W7Nb4O31 Nanorods with a Mixed Crystal Structure: A Very Fast‐ and Stable‐Charging Anode Material for Aqueous Lithium‐Ion Batteries.
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Yuan, Qiang, Zhu, Xiangzhen, Zhao, Yan, Wang, Lei, Lei, Yi, Liu, Xuehua, and Lin, Chunfu
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Aqueous lithium‐ion batteries (ALIBs) have attracted extensive interest since the safety problems of traditional lithium‐ion batteries are waived. Although the energy density of ALIBs is improved, their rate capability and power density are still poor due to the slow Li+ diffusivity of the existing anode materials, and their cyclic stability is also poor. Here, W7Nb4O31 nanorods with very fast‐ and stable‐charging capability are explored as a new anode material for ALIBs for the first time. This material owns different tetragonal tungsten bronze (TTB) structures together with 4 × 4 ReO3‐type blocks confined by TTB matrices, allowing abundant pentagonal and quadrangular tunnels for Li+ transport. These large‐sized tunnels combine with the large interlayer spacing (≈3.95 Å) not only lead to extremely fast Li+ diffusivity but also small unit‐cell volume variations (maximum 2.1%) during lithiation/delithiation, thereby enabling the LiMn2O4//W7Nb4O31 full cell to possess excellent rate capability with a 50C versus 1C capacity ratio of 68.3%, ultrahigh power density of 9854 W kg–1, and superior cyclic stability with capacity retention of 89.7/66.7/72.0% at 1C/5C/50C over 1000/10 000/10 000 cycles. This comprehensive study demonstrates that the W7Nb4O31 nanorods are highly promising for fast‐ and stable‐charging ALIBs. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Mechanism of concrete damage under the coupled action of freeze-thaw cycle and low-stress impact fatigue load:From pore structure to energy dissipation.
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Xu, Yanqun, Yuan, Qiang, De Schutter, Geert, Xiang, Gongkun, Hu, Chaolong, and Chen, Lei
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POROSITY , *FREEZE-thaw cycles , *ENERGY dissipation , *HIGH cycle fatigue , *DETERIORATION of concrete , *ECCENTRIC loads , *CONCRETE - Abstract
The interaction mechanism behind concrete damage induced by the combined effects of freeze-thaw cycles and fatigue load (FTF) remains insufficiently understood. This study aims to shed light on this mechanism by employing three sets of specimens, each subjected to different conditions: freeze-thaw cycles alone, low-stress impact fatigue (LIF) load alone, and FTF coupled action. Macro performance and microstructural changes of these specimens were measured after each testing round to analyze the evolution of concrete damage. Additionally, the influence of load duration on the damage under the coupled action was also explored. Results indicated that under FTF action, when LIF loading is applied for a short duration, freeze-thaw cycles play a dominant role in concrete damage, while the influence of LIF loading is minimal. However, when LIF loading is sustained for an extended period coupled with freeze-thaw cycles, it can accelerate concrete degradation. This can be attributed to the accumulation of micro-cracks during longer loading duration, eventually manifesting as visible cracks. These cracks link adjacent pores and increase the number of interconnected pores. This, coupled with freeze-thaw damage increasing the probability of crack forming, results in accelerated deterioration of concrete. The mechanism underlying this concrete deterioration was also analyzed from an energy dissipation prospect. • A setup was designed to simultaneously implement low-stress impact fatigue and freeze-thaw cycle. • The mechanisms of concrete damage under FTF action were discussed from the perspectives of pore structure and energy dissipation. • the influence of load duration on the concrete damage under the coupled action was explored. • The evolution of macro performance and microstructure properties were explored. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Understanding the water transport behaviors of hydrophobic cement mortar by paraffin modification.
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Yuan, Qiang, Zhong, Fuwen, Zuo, Shenghao, Xie, Zonglin, Xue, Kaiwei, and Yao, Hao
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MORTAR , *PARAFFIN wax , *ALKANES , *CEMENT , *WATER distribution , *CONTACT angle , *OIL spill cleanup - Abstract
The water transport behaviors of cement-based materials are altered after hydrophobic modification. The influence of hydrophobic modification on the water transport behaviors of mortar was investigated through 1H NMR and the absorption test. The results indicate that the incorporation of paraffin significantly reduces both the capillary and moisture absorption masses of mortar. The ratio of moisture absorption mass to capillary absorption mass increases with higher hydrophobicity, attributed to the paraffin coverage around the pores and the subsequent increase in contact angle. When incorporating 10 wt% paraffin, the increase in capillary absorption mass of mortar is mainly attributed to vapor diffusion and capillary condensation, accounting for 90.3 %. And the content of interlayer water, gel water, and inter-hydrate water in the two mentioned specimens is approximately equal, attributed to increased resistance to the ingress of liquid water. The reinforcement corrosion protection performance improves by one to two orders of magnitude due to the alteration of water transport behaviors. • Hydrophobic modification alters the proportion of various water transport behaviors. • 1H NMR is employed to characterize the distribution of water content in different water absorption environments. • When the hydrophobicity of the mortar increases, the capillary and moisture absorption specimens exhibit similar mass increments and absorption rates. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Corrigendum to "Experimental study of anchor bolt stress evaluation with hybrid optical fiber monitoring" [YOFTE 80C (2023) 103415].
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Fan, Jinsong, Yuan, Qiang, Wei, Like, Zhang, Long, Zhang, Dingding, Zhang, Dingshan, and Wang, Yi
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- 2024
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10. Spindle unit thermal error modeling and compensation based on digital twin.
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Liu, Jialan, Ma, Chi, and Yuan, Qiang
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The thermal error in the spindle unit is substantial and necessitates mitigation. Current models, being predominantly static in nature, have limited efficacy in error control. Integrating digital twin technology for modeling and controlling spindle unit thermal error holds promise in enhancing the machining accuracy of machine tools. Yet, the notion of a digital twin system specifically tailored for spindle unit thermal characteristics remains uncharted territory. To navigate these challenges, this study introduces a novel digital twin system tailored for spindle unit thermal characteristics. This system is poised to revolutionize thermal error modeling and compensation by harnessing the capabilities of digital twin technology. Within this digital twin framework, both the thermal error control model and the analytical thermal characteristic model are seamlessly integrated. The control model is devised as an exponential function, utilizing operational time, inherent time constants, and both initial and equilibrium thermal errors as parameters. Delving deeper, the analytical thermal characteristic model for the spindle system is rooted in a thermal resistance network approach. This leads to a closed-loop thermal characteristic modeling process, culminating in the derivation of a steady-state thermal error. Intricate heat transfer dynamics between spindle components are dissected, and a comprehensive thermal equilibrium equation set is formulated for the spindle unit. This equation set comprehensively accounts for dynamic variations in key parameters such as preload, lubricant viscosity, thermal load intensity, thermal contact resistance, and convective coefficients. To ascertain the time constant, a meticulously designed set of thermal characteristic experiments is executed. Subsequently, the digital twin system embarks on predictive modeling of thermal errors across varied operational conditions. This prediction then forms the foundation for thermal error compensation. With the integration of the present model into the digital twin system, the results are impressive: the absolute average and maximum deviations in thermal elongation, post-error control, stand at approximately 0.40 μm and 1.24 μm, respectively. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Confined water redistribution governs nanomechanical property changes of cement pastes curing at different air pressures.
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Zuo, Shenghao, Yuan, Qiang, Zhang, Kai, Huang, Tingjie, Xie, Zonglin, Shi, Jinyan, and Fang, Hongyuan
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CEMENT , *AIR pressure , *BENDING strength , *CURING , *WATER pressure , *HUMIDITY , *NANOINDENTATION - Abstract
The water status within concrete under low air pressure (AP) condition has been reported to affect the long-term properties of concrete in plateau regions, however, the underlying mechanism for the microstructural changes is not fully understood yet. In this paper, the confined water statuses within cement pastes curing at 98% RH and different APs (i.e. 101 kPa, 60 kPa, and 20 kPa) were first demonstrated and then correlated to the nanomechanical property changes of calcium-silicate-hydrates (C-S-H) phase by means of the 1H NMR relaxometry and nanoindentation techniques. The results show that low AP conditions increase the evaporable water content and drive the water movement from interlayer spaces to gel pores during wetting at 98% RH. According to the nanoindentation investigations, low AP conditions increase the volume fraction of high-density (HD) C-S-H and improve the nanomechanical and creep characteristics and bending strength of hardened cement pastes, which is attributed to the water redistribution within C-S-H phase. • Water statuses within cement pastes were identified by 1H NMR relaxometry. • Low air pressures drove water redistribution from interlayer space to gel pores. • Low air pressures changed nanomechanical characteristics of cement pastes. • Nanomechanical characteristics changed with water statuses of cement pastes. [ABSTRACT FROM AUTHOR]
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- 2024
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12. CO2 utilization and sequestration in ready-mix concrete—A review.
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Zhang, Suhui, Yuan, Qiang, Ni, Jun, Zheng, Keren, Xu, Yanqun, and Zhang, Jiaoling
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- 2024
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13. Fe,Co co-implanted dendritic CeO2/CeF3 heterostructure@MXene nanocomposites as structurally stable electrocatalysts with ultralow overpotential for the alkaline oxygen evolution reaction.
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Mao, Yunwei, Yang, Xiaotong, Dong, Kaiyu, Sheng, Tian, and Yuan, Qiang
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OXYGEN evolution reactions , *WATER electrolysis , *GREEN fuels , *ELECTROCATALYSTS , *OVERPOTENTIAL , *ACTIVATION energy , *ARTIFICIAL seawater - Abstract
A novel Fe, Co-CeO 2 /CeF 3 @MXene heterostructure with Fe-Co dual active sites and oxygen vacancies has been prepared for alkaline water/real seawater OER. [Display omitted] • Fe, Co-CeO 2 /CeF 3 @MXene heterostructure with Fe-Co dual active sites was synthesized by energy-free consumption co-deposition method. • Fe,Co-CeO 2 /CeF 3 @MXene can function as highly effective electrocatalyst toward OER. • The adsorption evolution mechanism and the lattice oxygen mechanism synergistically enhanced the OER activity. • Wind and solar-energy-assisted water electrolysis devices show their promising prospects for green hydrogen production sustainably. Exploring low-cost, high-activity, and structurally stable nonprecious metal electrocatalysts for sluggish oxygen evolution reaction (OER) is paramount for water electrolysis. Herein, we successfully prepare a novel Fe,Co-CeO 2 /CeF 3 @MXene heterostructure with Fe–Co dual active sites and oxygen vacancies for alkaline OER using an energy-free consumption co-deposition method. Impressively, Fe,Co-CeO 2 /CeF 3 @MXene achieves an ultralow overpotential of 192 mV and a long-term stability of 110 h at 10 mA cm−2 without structural changes, thereby outperforming the commercial IrO 2 (345 mV). In addition, Fe,Co-CeO 2 /CeF 3 @MXene exhibits much superior activity (271 mV) and durability to IrO 2 (385 mV) in the real seawater OER. Wind- and solar energy-assisted water electrolysis devices show their promising prospects for sustainable green hydrogen production. Characterization techniques and theoretical calculations reveal that the Fe,Co co-implanted CeO 2 /CeF 3 heterostructure effectively degrades the energy barrier of the OER and optimizes the adsorption strength of *OH, *O, and *OOH intermediates. It exhibits the dual coupling mechanism of the adsorbed evolution and lattice oxygen mechanisms, which synergistically improves the OER performance. This work provides a facile and efficacious strategy for synthesizing a new class of heterostructures to achieve significant enhancement in the activity and stability of OER catalysts. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Combined vacuum-assisted geotextile and geomembrane tubes for sludge dewatering: a theoretical switching point.
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Zhang, Hao, Sun, Hong-lei, Liu, Si-jie, Geng, Xue-yu, Deng, Yong-feng, and Cai, Yuan-qiang
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VACUUM tubes , *TUBES , *CHEST tubes , *GEOSYNTHETICS , *ANALYTICAL solutions , *TWO-dimensional models , *DESIGN services - Abstract
Treating the high water-content sludge with vacuum-assisted prefabricated horizontal drains (PHDs) placed inside, geotextile tubes have the advantage of multiple drainage paths, and geomembrane tubes have the superiority of high vacuum maintenance. Therefore, converting the geotextile tube into a geomembrane tube during slurry dewatering is an effective measure for greater dewatering efficiency and better dehydration effect. In this study, a profound plane-strain consolidation model considering two-dimensional seepage is developed for explaining the dewatering mechanism of sludge in the geo-tubes. Analytical solutions are given and validated by the experiment. The impact of major variables on tube efficiency is further discussed to reference the practice design. Parametric analyses reveal the critical time corresponding to the optimal efficiency of the geotextile tube, after which its consolidation efficiency decreases significantly. However, the consolidation efficiency of a geomembrane tube increases throughout the duration. Consequently, a switching point corresponding to the iso-efficiency state of the geotextile tube and geomembrane tube can be determined for the tube conversion. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Effect of carbon dioxide mineralization curing on mechanical properties and microstructure of Portland cement–steel slag–granulated blast furnace slag ternary paste.
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Cheng, Xu, Tian, Wei, Yuan, Qiang, Chen, Wensu, Wan, Jiahao, Guo, Jian, and Cai, Jiqi
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CARBON dioxide , *SLAG , *MICROSTRUCTURE , *MINERALIZATION , *CARBON fixation , *PASTE , *PORTLAND cement - Abstract
To investigate the synergistic effects of steel slag (SS) and granulated blast furnace slag (GBFS) on cementitious systems during carbon dioxide (CO 2) mineralization curing. Ternary paste specimens containing SS, GBFS, and Portland cement (PC) were prepared to analyze the influence of drying pre-treatment time and SS–GBFS mixing ratios on mechanical properties, CO 2 fixation rate, and microstructure evolution. Results emphasize the significance of appropriate drying pre-treatment in enhancing mineralization degree and compressive strength. At 60 °C drying pre-treatment temperature, extending drying pre-treatment time up to 12 h enhances both compressive strength and CO 2 fixation rate. However, beyond 12 h, a decline is observed in both parameters. Moreover, under the optimal drying pre-treatment time, the compressive strength of ternary paste specimens post-mineralization increases with higher SS content, with SS exerting a more pronounced positive effect on CO 2 fixation rate and compressive strength compared to GBFS. After 4 h of mineralization curing, specimens with 50% SS and 10% GBFS demonstrate a 13.16% increase in compressive strength and a 9.16% increase in CO 2 fixation rate compared to specimens with 10% SS and 50% GBFS. Microscopic test results reveal that the primary crystalline product in ternary paste specimens after mineralization is calcite, with traces of aragonite. The SS–GBFS mixing ratio has minimal effect on the type of reaction products but has a predominant influence on the total content and crystallinity of calcarea carbonica. • The increase of steel slag content can improve the degree of mineralization curing. • Increasing blast furnace slag reduces calcite crystallinity. • Steel slag boosts carbon fixation more than blast furnace slag. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Early Intraventricular Antibiotic Therapy Improved In-Hospital-Mortality in Neurocritical Patients with Multidrug-Resistant Bacterial Nosocomial Meningitis and Ventriculitis.
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Li, Zhiqi, Yang, Weijian, Ye, Xiangru, Yuan, Qiang, Zhao, Jianlan, Du, Zhuoying, Yu, Jian, Sun, Yirui, Wu, Xuehai, and Hu, Jin
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Background: Hospital-acquired multidrug-resistant (MDR) bacterial meningitis and/or ventriculitis (MEN) is a severe condition associated with high mortality. The risk factors related to in-hospital mortality of patients with MDR bacterial MEN are unknown. We aimed to examine factors related to in-hospital mortality and evaluate their prognostic value in patients with MDR bacterial MEN treated in the neurointensive care unit. Methods: This was a single-center retrospective cohort study of critically ill neurosurgical patients with MDR bacterial MEN admitted to our hospital between January 2003 and March 2021. Data on demographics, admission variables, treatment, time to start of intraventricular (IVT) therapy, and in-hospital mortality were analyzed. Both univariate and multivariable analyses were performed to identify determinants of in-hospital mortality. Results: All 142 included patients received systemic antibiotic therapy, and 102 of them received concomitant IVT treatment. The median time to start of IVT treatment was 2 days (interquartile range 1–5 days). The time to start of IVT treatment had an effect on in-hospital mortality (hazard ratio 1.17; 95% confidence interval 1.02–1.34; adjusted p = 0.030). The cutoff time to initiate IVT treatment was identified at 3 days: patients treated within 3 days had a higher cerebrospinal fluid (CSF) sterilization rate (81.5%) and a shorter median time to CSF sterilization (7 days) compared with patients who received delayed IVT treatment (> 3 days) (48.6% and 11.5 days, respectively) and those who received intravenous antibiotics alone (42.5% and 10 days, respectively). Conclusions: Early IVT antibiotics were associated with superior outcomes in terms of the in-hospital mortality rate, time to CSF sterilization, and CSF sterilization rate compared with delayed IVT antibiotics and intravenous antibiotics alone. [ABSTRACT FROM AUTHOR]
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- 2024
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17. High‐refraction index glasses with ultra‐high Young's modulus and high hardness fabricated by containerless processing.
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Ma, Kaicheng, Yu, Jianding, Li, Qin, He, Huan, Ni, Jinqi, Fang, Jinghong, Xiong, Yifei, Yuan, Qiang, Zhang, Qian, and Li, Tongtong
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YOUNG'S modulus , *GLASS , *HARDNESS , *VICKERS hardness , *REFRACTIVE index , *METALLIC oxides - Abstract
High‐refractive index glasses with ultra‐high Young's modulus and superior hardness have significant application in optical lenses. Research indicates that high‐entropy glasses, enriched with high dissociation energy and high‐field strength components, enhance the mechanical properties of glass. In this study, we tailored high‐entropy glasses to achieve superior optical and mechanical attributes by optimizing heavy metal oxide components and adjusting the Al2O3 content. The resultant 10RE2O3‐10Gd2O3‐32Al2O3‐36Ta2O5‐12ZrO2 (RE = La, Tm, Lu) glass demonstrates a refractive index of 2.028, a Young's modulus of 186.2 GPa, and a Vickers hardness of 9.18 GPa. The glass was colorless and widely transparent, in the visible‐to‐infrared region from 312.5 to 6674 nm, and the maximum transmittance reach up to 79.3%. These results indicate that the 10RE2O3‐10Gd2O3‐32Al2O3‐36Ta2O5‐12ZrO2 glass would be useful for camera and detector lenses. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Hardened property changes due to the pumping process of self-consolidating concrete.
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Li, Fumin, Shen, Wenkai, Yuan, Qiang, Chen, Zheng, Zhang, Shuqing, Ji, Youhong, Zeng, Rong, Wu, Youwu, Lao, Lilin, and Shi, Caijun
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SELF-consolidating concrete , *ELASTIC modulus , *COMPRESSIVE strength , *CONCRETE , *CRACKING of concrete - Abstract
Pumping of self-consolidating concrete (SCC) is a vital construction technique. Curiosities are aroused by the effect of this intense physical process on the hardened properties of SCC. To examine this issue, a total of seven SCC mixtures are pumped at constant flow rates in pipelines with lengths of 324, 600, and 912 m. Parameters related to the hydration stages, air-void system, compressive strength, elastic modulus, and shrinkage at early ages are tested on specimens made of concrete before and after pumping. Results of tested samples find that the spacing factor grows, but the specific surface lessens after pumping. Also, in most cases, the compressive strength and elastic modulus decrease due to the pumping. The variations of these two factors are linearly related to the pumping distance in most cases. Additionally, the variations in the early age of shrinkage cracking show a dependency on the concrete compositions, temperature, and pumping characteristics. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Exploring dark matter spike distribution around the Galactic centre with stellar orbits.
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Shen, Zhao-Qiang, Yuan, Guan-Wen, Jiang, Cheng-Zi, Tsai, Yue-Lin Sming, Yuan, Qiang, and Fan, Yi-Zhong
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DARK matter , *VERY large telescopes , *SUPERMASSIVE black holes , *ORBITS (Astronomy) , *STELLAR dynamics , *STELLAR orbits - Abstract
Precise measurements of the stellar orbits around Sagittarius A* have established the existence of a supermassive black hole (SMBH) at the Galactic centre (GC). Due to the interplay between the SMBH and dark matter (DM), the DM density profile in the innermost region of the Galaxy, which is crucial for the DM indirect detection, is still an open question. Among the most popular models in the literature, the theoretical spike profile proposed by Gondolo & Silk (GS hereafter) is well adopted. In this work, we investigate the DM spike profile using updated data from the Keck and Very Large Telescope (VLT) telescopes considering that the presence of such an extended mass component may affect the orbits of the S-stars in the GC. We examine the radius and slope of the generalized Navarro–Frenk–White (NFW) spike profile, analyse the Einasto spike, and discuss the influence of DM annihilation on the results. Our findings indicate that an initial slope of γ ≳ 0.92 for the generalized NFW spike profile is ruled out at a 95 per cent confidence level. Additionally, the spike radius R sp larger than 21.5 pc is rejected at 95 per cent probability for the Einasto spike with α = 0.17, which also contradicts the GS spike model. The constraints with the VLT/GRAVITY upper limits are also projected. Although the GS NFW spike is well constrained by the Keck and VLT observation of S2, an NFW spike with a weak annihilation cusp may still be viable, as long as the DM annihilation cross-section satisfies |$\left\langle \sigma v \right\rangle \gtrsim 7.7\times 10^{-27}~{\rm cm^3\, s^{-1}} (m_{\rm DM}/100~{\rm GeV})$| at 95 per cent level. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Overview of Health-Monitoring Technology for Long-Distance Transportation Pipeline and Progress in DAS Technology Application.
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Wu, Yuyi, Gao, Lei, Chai, Jing, Li, Zhi, Ma, Chenyang, Qiu, Fengqi, Yuan, Qiang, and Zhang, Dingding
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PIPELINE transportation , *ENVIRONMENTAL risk , *TECHNOLOGY transfer , *POLLUTION , *HEALTH literacy - Abstract
There are various health issues associated with the different stages of long-distance pipeline transportation. These issues pose potential risks to environmental pollution, resource waste, and the safety of human life and property. It is essential to have real-time knowledge of the overall health status of pipelines throughout their entire lifecycle. This article investigates various health-monitoring technologies for long-distance pipelines, providing references for addressing potential safety issues that may arise during long-term transportation. This review summarizes the factors and characteristics that affect pipeline health from the perspective of pipeline structure health. It introduces the principles of major pipeline health-monitoring technologies and their respective advantages and disadvantages. The review also focuses on the application of Distributed Acoustic Sensing (DAS) technology, specifically time and space continuous monitoring technology, in the field of pipeline structure health monitoring. This paper discusses the process of commercialization development of DAS technology, the main research progress in the experimental field, and the open research issues. DAS technology has broad application prospects in the field of long-distance transportation pipeline health monitoring. [ABSTRACT FROM AUTHOR]
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- 2024
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21. Machine learning models for early prediction of potassium lowering effectiveness and adverse events in patients with hyperkalemia.
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Huang, Wei, Zhu, Jian-Yong, Song, Cong-Ying, and Lu, Yuan-Qiang
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MACHINE learning , *HYPERKALEMIA , *DIASTOLIC blood pressure , *POTASSIUM , *GLOMERULAR filtration rate , *PREDICTION models - Abstract
The aim of this study was to develop a model for early prediction of adverse events and treatment effectiveness in patients with hyperkalemia. We collected clinical data from patients with hyperkalemia in the First Hospital of Zhejiang University School of Medicine between 2015 and 2021. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to analyze the predictors on the full dataset. We randomly divided the data into a training group and a validation group, and used LASSO to filter variables in the training set. Six machine learning methods were used to develop the models. The best model was selected based on the area under the curve (AUC). Shapley additive exPlanations (SHAP) values were used to explain the best model. A total of 1074 patients with hyperkalemia were finally enrolled. Diastolic blood pressure (DBP), breathing, oxygen saturation (SPO2), Glasgow coma score (GCS), liver disease, oliguria, blood sodium, international standardized ratio (ISR), and initial blood potassium were the predictors of the occurrence of adverse events; peripheral edema, estimated glomerular filtration rate (eGFR), blood sodium, actual base residual, and initial blood potassium were the predictors of therapeutic effect. Extreme gradient boosting (XGBoost) model achieved the best performance (adverse events: AUC = 0.87; therapeutic effect: AUC = 0.75). A model based on clinical characteristics was developed and validated with good performance. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Machine learning models for early prediction of potassium lowering effectiveness and adverse events in patients with hyperkalemia.
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Huang, Wei, Zhu, Jian-Yong, Song, Cong-Ying, and Lu, Yuan-Qiang
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MACHINE learning , *HYPERKALEMIA , *DIASTOLIC blood pressure , *POTASSIUM , *GLOMERULAR filtration rate , *PREDICTION models - Abstract
The aim of this study was to develop a model for early prediction of adverse events and treatment effectiveness in patients with hyperkalemia. We collected clinical data from patients with hyperkalemia in the First Hospital of Zhejiang University School of Medicine between 2015 and 2021. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to analyze the predictors on the full dataset. We randomly divided the data into a training group and a validation group, and used LASSO to filter variables in the training set. Six machine learning methods were used to develop the models. The best model was selected based on the area under the curve (AUC). Shapley additive exPlanations (SHAP) values were used to explain the best model. A total of 1074 patients with hyperkalemia were finally enrolled. Diastolic blood pressure (DBP), breathing, oxygen saturation (SPO2), Glasgow coma score (GCS), liver disease, oliguria, blood sodium, international standardized ratio (ISR), and initial blood potassium were the predictors of the occurrence of adverse events; peripheral edema, estimated glomerular filtration rate (eGFR), blood sodium, actual base residual, and initial blood potassium were the predictors of therapeutic effect. Extreme gradient boosting (XGBoost) model achieved the best performance (adverse events: AUC = 0.87; therapeutic effect: AUC = 0.75). A model based on clinical characteristics was developed and validated with good performance. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Long-term efficacy of microwave ablation for multifocal papillary thyroid microcarcinoma: a 5-year follow-up study.
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Dong, Peng, Teng, Deng-Ke, Sui, Guo-Qing, Lin, Yuan-Qiang, Luo, Qiang, Wang, Qi-Meihui, Li, He-Qun, and Wang, Hui
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PAPILLARY carcinoma , *THYROIDECTOMY , *THYROID cancer , *MICROWAVES , *WATCHFUL waiting , *LYMPHATIC metastasis , *TREATMENT effectiveness - Abstract
Objectives: Microwave ablation (MWA) has achieved excellent long-term efficacy in treating unifocal papillary thyroid microcarcinoma (UPTMC). The therapeutic effect of this treatment on multifocal papillary thyroid microcarcinoma (MPTMC) is unknown. Therefore, we evaluated the long-term efficacy of MWA for low-risk MPTMC and to provide evidence-based medicine for the revision of clinical guidelines. Methods: This study included 66 MPTMC patients with a total of 158 lesions, all of whom received MWA. We collected and retrospectively analyzed the patients' follow-up data before MWA, at 1, 3, 6, and 12 months posttreatment and every 6 months thereafter until 5 years posttreatment. We evaluated the MWA complication rate, technical success rate (TSR), lesion volume reduction rate (VRR), and complete disappearance rate (CDR) during follow-up and in those patients with tumor progression and delayed surgery. Results: After 60 months of follow-up, all 158 lesions disappeared in 66 patients, and the volume was reduced from 43.82 mm3 to 0.00 mm3. The TSR and VRR were both 100%. The CDRs at 1 year, 2 years, and 3 years were 57.59%, 93.67%, and 100%, respectively. The complication rate was 3.03% (2/66), and the incidence of tumor progression was 3.03% (2/66), including one new intrathyroidal lesion and one cervical lymph node metastasis (LNM). These lesions were retreated with MWA, and the lesions disappeared during the follow-up period. Conclusions: Ultrasound-guided MWA for low-risk MPTMC is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance (AS). Clinical relevance statement: This study concludes that ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance. Key Points: • Ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective. • During 5 years of follow-up, multifocal papillary thyroid microcarcinoma patients treated with microwave ablation had a favorable prognosis. • To provide evidence-based medicine for the revision of clinical guidelines. [ABSTRACT FROM AUTHOR]
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- 2024
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24. The clinical trajectory of peripheral blood immune cell subsets, T-cell activation, and cytokines in septic patients.
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Lu, Xuan, Song, Cong-Ying, Wang, Ping, Li, Li, Lin, Li-Ying, Jiang, Shuai, Zhou, Jia-Ning, Feng, Meng-Xiao, Yang, Yun-Mei, and Lu, Yuan-Qiang
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BLOOD cells , *T cells , *REGULATORY T cells , *KILLER cells , *B cells - Abstract
Objective and design: Changes in the immune status of patients with sepsis may have a major impact on their prognosis. Our research focused on changes in various immune cell subsets and T-cell activation during the progression of sepsis. Methods and subjects: We collected data from 188 sepsis patients at the First Affiliated Hospital of Zhejiang University School of Medicine. The main focus was on the patient's immunocyte subset typing, T-cell activation/Treg cell analysis, and cytokine assay, which can indicate the immune status of the patient. Results: The study found that the number of CD4+ T cells, CD8+ T cells, NK cells, and B cells decreased early in the disease, and the decrease in CD4+ and CD8+ T cells was more pronounced in the death group. T lymphocyte activation was inhibited, and the number of Treg cells increased as the disease progressed. T lymphocyte inhibition was more significant in the death group, and the increase in IL-10 was more significant in the death group. Finally, we used patients' baseline conditions and immunological detection indicators for modeling and found that IL-10, CD4+ Treg cells, CD3+HLA-DR+ T cells, and CD3+CD69+ T cells could predict patients' prognosis well. Conclusion: Our study found that immunosuppression occurs in patients early in sepsis. Early monitoring of the patient's immune status may provide a timely warning of the disease. [ABSTRACT FROM AUTHOR]
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- 2024
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25. Unveiling the impact of organic phase aging on the long-term damping capacity of cement-styrene butadiene rubber composites.
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Xie, Zonglin, Xiang, Gongkun, Zhong, Fuwen, Tian, Yi, Li, Haiyang, Lei, Jinshan, and Yuan, Qiang
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POLYBUTADIENE , *DAMPING capacity , *MOLECULAR structure , *DOUBLE bonds , *HYDROXYL group - Abstract
Given the crucial role of cement-styrene butadiene rubber (SBR) composites in the application of damping structural materials, their long-term damping performance needs to incorporate a focused examination of organic phase aging. This study investigated the changes in the dynamic mechanical properties of these composites subjected to thermo-oxidative and ultraviolet aging, and explored the damping degradation mechanisms specific to SBR. The results demonstrated a significant reduction in the damping capability of the composites under aging, exceeding 19.5 %, 33.9 %, and 46.0 % after 1, 2, and 4 years of service, respectively. The decrease is attributed to the alteration in the molecular structure of SBR, which includes the oxidation of the α-H double bond to a hydroxyl group, followed by a dehydrogenation reaction leading to the formation of aldehyde. Furthermore, the study utilized a three-element standard solid model to elucidate the frequency-dependent dynamic mechanical properties of the cement-SBR composites. • The dynamic mechanical properties of cement-SBR composites were monitored under aging processes. • The aging mechanism of SBR polymer was investigated under aging processes. • A three-element standard solid model was proposed to elucidate the dynamic mechanical properties of the cement-SBR composites. [ABSTRACT FROM AUTHOR]
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- 2024
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26. Early-age thermo-hydro-mechanical properties of reinforced concrete bridge piers on the plateau.
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Zhang, Kai, Lei, Jinshan, Zuo, Shenghao, Li, Qiuyi, Zhang, Wangzhao, Wu, Haibo, and Yuan, Qiang
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REINFORCED concrete , *BRIDGE foundations & piers , *CONCRETE bridges , *HEAT of hydration , *CENTER of mass , *THERMAL insulation - Abstract
The reinforced concrete (RC) piers located on the plateau suffer a thermo-hydro-mechanical response at an early age, which severely damages the safety and durability of bridges. In this research, five RC piers were constructed on a plateau (altitude: 4360 m) to explore the development of bridge pier early-age temperature and strain. Thermo-hydro-mechanical finite element analyses were then performed to investigate the early-age temperature, moisture, and deformation properties of the RC pier on the plateau. The findings demonstrate that employing thermal insulation curing, modifying the cement ultimate hydration heat, and minimizing the concrete w/c ratio could mitigate the pier early-age temperature gradient and moisture loss. The concrete hydration degree and compressive strength are often greater around the pier gravity center than in other situations. After 96 h of curing, the compressive strength of the concrete at the pier gravity center is approximately 1.766 times that of the pier surface concrete. The most unfavorable locations for bridge piers are at the arc surface and the bottom of the plane. • Early-age thermo-hydro-mechanical properties of bridge piers on the plateau were investigated. • A thermo-hydro-mechanical analysis methodology is suggested to examining the early-age properties of RC structures. • Several solutions were suggested for minimizing the early-age damage of RC pier on the plateau. [ABSTRACT FROM AUTHOR]
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- 2024
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27. Improving the air bubble stability of air-entrained mortar in low air pressure environments via adopted rheology and surface tension methods.
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Xie, Zonglin, Zuo, Shenghao, Chen, Lei, Zhong, Fuwen, Tian, Yi, and Yuan, Qiang
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RHEOLOGY , *OSTWALD ripening , *AIR pressure , *MTV Video Music Awards , *CEMENT - Abstract
Air bubble stability in cementitious materials in low air pressure (AP) environments is influenced by the Ostwald ripening process, which causes coarsening behavior of air bubbles. This research reports the enhancement of air bubble stability in low AP via the adoption of rheology and surface tension methods. Besides, the evolution of air bubbles during the cement early hydration process is proposed. It was found that incorporating viscosity-modifying agents (VMAs) and shrinkage-reducing admixtures (SRAs) resulted in improving air bubble stability by 37.7 % and 23.4 %, upon undergoing AP change from 100 to 60 kPa. Calculation of air bubbles via ripening equations under low AP revealed that VMA induced a notable decrease in the effective diffusion flux within fresh cement mortar, leading to a reduction of 9.8 % in air bubble ripening within 120 min. Conversely, SRAs were primarily aimed at reducing the initial dimensions of air bubbles. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Using metakaolin to improve properties of aged Portland cement: Effectiveness and the mechanism.
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Li, Mengya, Zheng, Keren, Chen, Lou, Prateek, Ghimire, Zhou, Xiaofeng, and Yuan, Qiang
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KAOLIN , *PORTLAND cement , *ATMOSPHERIC carbon dioxide , *HYDRATION kinetics , *HUMIDITY , *AGE groups - Abstract
Aging of Portland cement, due to its reaction with moisture and atmospheric CO 2 prior to regular use, has the potential to severely impair its hydration reactivity. The effectiveness of using metakaolin to improve the properties of aged Portland cement exposed to a laboratory conditions (RH=65 %, 20 °C) as well as the associated mechanism are studied. The incorporation of 5–10 % metakaolin changes the early-stage hydration kinetics of aged cement obviously by enhancing reactions of both C 3 S and C 3 A through the filler effect at the early hydration stage, thereby mitigating detrimental influences of aging on setting time and early-age strength development (up to 7 days). Metakaolin exhibits significant effectiveness on enhancing 28-day strength of aged cement, and the enhancement arises from the synergic reaction between metakaolin and CaCO 3 , which converts CaCO 3 resulting from aging into carboaluminate phases and produces secondary C-S-H. The incorporation of 5 % metakaolin increases the 28-day compressive strength of the sample with cement aged for one month to a comparable level as that of fresh cement. • Aging leads to relaxation and reconstruction of the cement surface can hinder the activity of the cement. • The filler effect caused by metakaolin promotes the reaction of C 3 S and C 3 A in aged cement. • The synergistic reaction between metakaolin and CaCO 3 formed in aged cement improves the mechanical property. [ABSTRACT FROM AUTHOR]
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- 2024
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29. In sight the behavior of natural Bletilla striata polysaccharide hydrocolloids by molecular dynamics method.
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Liu, Ju-Zhao, Wang, Lu, Jiang, Li-Jie, Lyu, Hong-Chang, Yuan, Qiang, Wang, Guang-Fu, Fu, Yu-Jie, and Cui, Qi
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- *
MOLECULAR dynamics , *HYDROCOLLOIDS , *HIGH temperatures , *DIHEDRAL angles , *LOW temperatures , *AQUEOUS solutions , *POLYSACCHARIDES , *XANTHAN gum - Abstract
Plant polysaccharides, distinguished by diverse glycosidic bonds and various cyclic sugar units, constitute a subclass of primary metabolites ubiquitously found in nature. Contrary to common understanding, plant polysaccharides typically form hydrocolloids upon dissolution in water, even though both excessively high and low temperatures impede this process. Bletilla striata polysaccharides (BSP), chosen for this kinetic study due to their regular repeating units, help elucidate the relationship between polysaccharide gelation and temperature. It is suggested that elevated temperatures enhance the mobility of BSP molecular chains, resulting in a notable acceleration of hydrogen bond breakage between BSP and water molecules and consequently, compromising the conformational stability of BSPs to some extent. This study unveils the unique relationship between polysaccharide dissolution processes and temperature from a kinetics perspective. Consequently, the conclusion provides a dynamical basis for comprehending the extraction and preparation of natural plant polysaccharide hydrocolloids, pharmaceuticals and related fields. • The structure and conformation of Bletilla striata polysaccharide (BSP) composed of glucose and mannose residues was studied. • RMSD, Rg, FEL, RMSF, hydrogen bond, RDF, SASA, dihedral angle characteristics of BSP in aqueous solutions were investigated. • Elevated temperatures increased hydrogen bond-breaking rate between BSP and water molecules, destabilizing its conformation. • This study unveils the unique relationship between polysaccharides dissolution processes and temperature. • Studying the dynamic behavior of polysaccharide enhances cognition of the formation mechanism of polysaccharide hydrocolloid. [ABSTRACT FROM AUTHOR]
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- 2024
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30. Retraction: TGF-β1 Regulation of Estrogen Production in Mature Rat Leydig Cells.
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Liu, Man-Li, Wang, Huan, Wang, Zong-Ren, Zhang, Yu-Fen, Chen, Yan-Qiu, Zhu, Fang-Hong, Zhang, Yuan-Qiang, Ma, Jing, and Li, Zhen
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LEYDIG cells , *ESTROGEN regulation , *RATS - Abstract
This document is a retraction notice for an article titled "TGF-β1 Regulation of Estrogen Production in Mature Rat Leydig Cells." The authors of the article have requested to retract it due to unresolved issues with one of the figures and the unavailability of data. The authors stand by the findings of the article but are unable to be accountable for the reported work. They apologize for the issues with the published article. [Extracted from the article]
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- 2024
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31. Pressure-based analysis of rheological equilibrium distances of pumped self-consolidating concrete (SCC).
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Li, Fumin, Shen, Wenkai, Ji, Youhong, Zeng, Rong, Wu, Youwu, Lao, Lilin, Shi, Caijun, and Yuan, Qiang
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SELF-consolidating concrete , *EQUILIBRIUM , *YIELD stress , *VISCOSITY , *HEMORHEOLOGY , *PREDICTION models - Abstract
The influence of pumping on the rheological properties of self-consolidating concrete (SCC) is widely recognized, but there is still limited understanding of its behavior within the pipeline. In this study, we propose a novel approach using equilibrium distances to investigate the evolution of rheological properties along the pipeline. Full-scale horizontal pumping circuits spanning 328 m were established to assess the axial development of SCC's rheological properties. Thirteen mixtures, with water-to-cement (w/c) ratios ranging from 0.22 to 0.27, were pumped at discharge rates varying from 5.77 to 12.69 L/s. Our findings show that for pumping setups and material studied, both the w/c ratio of SCC and the discharge rate significantly affected the influence of rheological equilibrium distances on pressure loss gradient changes. In all tested samples, viscosity values required the entire length of the pipeline to reach post-pumping levels, while yield stress values rapidly achieved their fully developed state upon entering the pipeline. Importantly, the predicted pressure loss displayed a strong correlation with experimental measurements, with an accuracy of 89.42% across all tested mixtures. Our predictive model showed an average improvement of 4.6% in accuracy compared to the linear approach, with the most significant enhancement observed in samples with higher w/c ratios. This research sheds new light on the behavior of SCC during pumping and provides valuable insights for optimizing the pumping process. • The equilibrium distance of rheology is introduced to describe SCC flow behavior along the pipeline. • Horizontal pumping circuits spanning 328 m is used. • Factors affecting the equilibrium distance of rheology are discussed. • The prediction accuracy of the model is validated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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