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Construction of a multifunctional Ti_(3)C_(2)T_(x)MXene/g-C_(3)N_(4)artificial protective layer for dendrite-free aqueous Zn-ion batteries

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Rare Metals 2024年第10期43卷 4992-5004页

作者： Wei-Wei Wang Rui Huang yu Tao Peng He Su-Xing tuo yu-Jian Bian Rui-Ting Hu Jun Yan Yan-Jie Liang wen-Chao Zhang The Key Laboratory of Digital Flavour Research of Hunan China Tobacco Industry Co. LtdChangsha 410019China College of Metallurgy and Environment Central South UniversityChangsha 410083China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China

The electrochemical utilization of Zn anodes in aqueous batteries is hampered by the intricate and interconnected issues of Zn dendrite growth,H_(2)evolution and Zn corrosion *** this study,a multifunctional protective layer comprising MXene and graphitic carbon nitride(g-C_(3)N_(4))was constructed using a self-assembly *** MXene/g-C_(3)N_(4)protective layer exhibited robust zincophilic characteristics,which facilitated a uniform distribution of the electric field and ensured a sufficient influx of Zn^(2+).This reduces the Zn^(2+)nucleation barrier and prevents dendrite *** addition,the hydrophobic nature of the protective layer,coupled with its negative charge,can repel SO_(4)^(2-)and select water molecules from the electrolyte,which aids in mitigating corrosion and H_(2)*** symmetric Zn cell coated with the MXene/g-C_(3)N_(4)protective layer showed remarkable stability,achieving over 2000 h of reversible cycling at1 mA·cm^(-2).Furthermore,the MXene/g-C_(3)N_(4)-coated Zn anode paired with a sodium-doped V_(2)O_5cathode(NVO)exhibited enhanced cycling capability over 1500 cycles.

关键词： Ti_(3)C_(2)T_(x)MXene g-C_(3)N_(4) Artificial protective layers Interface stability Dendrite-free Zn anodes

Effect of yttrium addition on microstructure, mechanical and corrosion properties of 20Cr13 martensitic stainless steel

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Journal of Iron and Steel Research International 2020年第4期27卷 451-460页

作者： Qi-yu Zang Yang-fan Jin tuo Zhang Yi-tao Yang School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

The effects of rare-earth yttrium(Y)element on the microstructure,mechanical properties and corrosion properties of 20Cr13 martensitic stainless steel were investigated by optical microscopy,scanning electron microscopy and tensile *** experiments were carried out to study the effect of rare-earth element Y addition on corrosion *** results showed that the addition of 0.02 wt.%rare-earth yttrium to martensitic stainless steel could affect the microstructure transformation,and Ac3 temperature was obviously *** the stainless steel after heat treatment,there were more pro-eutectoid ferrite in the steel with 0.02 wt.%*** mechanical test results showed that the addition of 0.02 wt.%yttrium could significantly improve the tensile strength and elongation of the steel,which was related to the influence of yttrium element on inclusions in the test *** the quenching temperature of 0.02 wt.%yttrium steel increasing,the content of the ferrite in steel was affected and the corrosion resistance was remarkably improved.

关键词： Yttrium Martensitic stainless steel Mechanical property Microstructural characterization Corrosion

Parameter sensitivity analysis for a biochemically-based photosynthesis model

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Research in Cold and Arid Regions 2023年第2期15卷 73-84页

作者： tuo Han Qi Feng TengFei yu Key Laboratory of Eco-Hydrology of Inland River Basin Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)LanzhouGansu 730000China

A challenge for the development of Land Surface Models(LSMs) is improving transpiration of water exchange and photosynthesis of carbon exchange between terrestrial plants and the atmosphere, both of which are governed by stoma in leaves. In the photosynthesis module of these LSMs, variations of parameters arising from diversity in plant functional types(PFTs) and climate remain unclear. Identifying sensitive parameters among all photosynthetic parameters before parameter estimation can not only reduce operation cost, but also improve the usability of photosynthesis models worldwide. Here, we analyzed 13 parameters of a biochemically-based photosynthesis model(FvCB), implemented in many LSMs, using two sensitivity analysis(SA) methods(i.e., the Sobol’ method and the Morris method) for setting up the parameter ensemble. Three different model performance metrics, i.e.,Root Mean Squared Error(RMSE), Nash Sutcliffe efficiency(NSE), and Standard Deviation(STDEV) were introduced for model assessment and sensitive parameters identification. The results showed that among all photosynthetic parameters only a small portion of parameters were sensitive, and the sensitive parameters were different across plant functional types: maximum rate of Rubisco activity(Vcmax25), maximum electron transport rate(Jmax25), triose phosphate use rate(TPU) and dark respiration in light(Rd) were sensitive in broad leafevergreen trees(BET), broad leaf-deciduous trees(BDT) and needle leaf-evergreen trees(NET), while only Vcmax25and TPU are sensitive in short vegetation(SV), dwarf trees and shrubs(DTS), and agriculture and grassland(AG). The two sensitivity analysis methods suggested a strong SA coherence;in contrast, different model performance metrics led to different SA results. This misfit suggests that more accurate values of sensitive parameters, specifically, species specific and seasonal variable parameters, are required to improve the performance of the FvCB model.

关键词： Sobol’method Morris method Photosynthesis Parameters sensitivity analysis FvCB model

Behavior of Nb influence on structure and properties of 30Cr13 cast martensitic stainless steel

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Journal of Iron and Steel Research International 2019年第5期26卷 462-471页

作者： Yang-fan Jin tuo Zhang Qi-yu Zang Yi-tao Yang School of Materials Science and Engineering Shanghai University Shanghai 200444 China

The microstructure, mechanical properties and corrosion resistance of 30Cr13 martensitic stainless steel (MSS) with different Nb contents were investigated by using the optical microscope, scanning electron microscope, X-ray diffractometer, HRC hardness measurement apparatus and tensile testing machine. Nb was found to retard the formation of austenite and promote the precipitation of carbides by calculating. The results showed that the addition of 0.2 wt.% Nb elements could improve the strength and corrosion resistance of 30Cr13 martensitic stainless steels while the reduction in toughness was less because of the inhibited effect on Cr-rich carbides precipitation by Nb addition. Specially, M23C6-type carbides almost disappeared in 0.6Nb-MSS. Moreover, the main existent form of Nb element was NbC and the strong carbide-forming ability of Nb element increased the quantity of carbides with the morphology changing from sphericaltype to chain-type. 0.2Nb-MSS shows excellent strength, adequate toughness and sufficient corrosion resistance for the application.

关键词： Niobium addition Martensitic stainless steel Microstructure Mechanical property Corrosion resistance

On Proximinality of Convex Sets in Superspaces

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Acta Mathematica Sinica,English Series 2016年第6期32卷 633-642页

作者： Li Xin CHENG Zheng Hua LUO wen ZHANG Ben tuo ZHENG School of Mathematical Sciences Xiamen University School of Mathematical Sciences Huaqiao University Department of Mathematical Sciences the University of Memphis

Abstract In this paper, we show that a closed convex subset C of a Banach space is strongly proximinal （proximinal, resp.） in every Banach space isometrically containing it if and only if C is locally （weakly, resp.） compact. As a consequence, it is proved that local compactness of C is also equivalent to that for every Banach space Y isometrically containing it, the metric projection from Y to C is nonempty set-valued and upper semi-continuous.

关键词： Proximinality convex set local compactness Banach space

Health performance assessment modeling and its application to compact medical communities in China

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Health Care Science

Health Care Science 2024年第4期3卷 232-237页

作者： Miao yu Zhongmou Huang Dan Zhang Yansui Yang Ching‐wen Chien Hongwu tuo Institute for Hospital Management Tsinghua UniversityBeijingChina Institute for Hospital Management Shenzhen International Graduate SchoolTsinghua UniversityShenzhenChina Guangzhou College of Technology and Business GuangzhouChina

Some regions in China have already implemented capitation payment or capitation budget management for medical insurance ***,there remains a shortage of adequate tools and methodologies to accurately quantify differences in population health ***,this paper constructs a health performance assessment model that comprises four *** first step is to categorize all participants into health risk groups based on whether they have contracted with a family doctor,their age,sex,and the type of *** second step is to categorize health risk groups based on differences in healthcare resource *** third step is to analyze health performance by examining healthcare resource utilization year over *** fourth step is to apply the assessment results to assist local finance bureaus and medical insurance bureaus in developing incentive *** to cost weights,the health risk groups are split into six classes:insured residents without health care visits,healthy insured person,slightly ill insured patients,ill insured patients,more seriously disease patients,and severely ill insured *** evaluate one compact medical community's health performance by examining changes in the proportion of resource usage group size and *** 2019 to 2021,both the proportion of patients with severe and ultra‐severe diseases and the proportion of costs in the sample increased,according to changes in resource utilization *** result indicates that the population's overall health has not improved and that the compact medical community is still primarily focused on treating diseases,with poor implementation of health maintenance measures and minimal improvement in health performance.

关键词： compact medical community health performance assessment medical insurance

A novel profile modification HPF-Co gel satisfied with fractured low permeability reservoirs in high temperature and high salinity

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Petroleum Science 2024年第1期21卷 683-693页

作者： Ya-Kai Li Ji-Rui Hou Wei-Peng Wu Ming Qu tuo Liang Wei-Xin Zhong yu-Chen wen Hai-Tong Sun Yi-Nuo Pan China University of Petroleum Beijing Beijing102249China PetroChina Tarim Oilfield Company Korla 841000XinjiangChina Key Laboratory of Improving Oil and Gas Recovery of Ministry of Education Northeast Petroleum University Daqing 163318HeilongjiangChina Xi'an Shiyou University Xi'an 710065ShaanxiChina Northwest Oilfield Company SINOPECUrumqi 830011XinjiangChina

Conformance control and water plugging are a widely used EOR method in mature ***,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and high-salinity low permeability ***,a novel conformance control system HPF-Co gel,based on high-temperature stabilizer(CoCl_(2)·H_(2)O,CCH)is *** HPF-Co bulk gel has better performances with high temperature(120℃)and high salinity(1×10^(5)mg/L).According to Sydansk coding system,the gel strength of HPF-Co with CCH is increased to code *** dehydration rate of HPF-Co gel is 32.0%after aging for 150 d at 120℃,showing excellent thermal *** rheological properties of HPF gel and HPF-Co gel are also *** results show that the storage modulus(G′)of HPF-Co gel is always greater than that of HPF *** effect of CCH on the microstructure of the gel is *** results show that the HPF-Co gel with CCH has a denser gel network,and the diameter of the three-dimensional network skeleton is 1.5-3.5μ*** 90 d of aging,HPF-Co gel still has a good three-dimensional *** spectroscopy results show that CCH forms coordination bonds with N and O atoms in the gel amide group,which can suppress the vibration of cross-linked sites and improve the stability at high *** core plugging test determines the optimized polymer gel injection strategy and injection velocity with HPF-Co bulk gel system,plugging rate exceeding 98%.Moreover,the results of subsequent waterflooding recovery can be improved by 17%.

关键词： Low permeability reservoir High-temperature resistant gel Complexation reaction Polymer gel injection strategy Plugging rate Enhanced oil recovery

Phase-field simulation of solidification dendritic segregation in Ti-45Al alloy

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China Foundry 2017年第3期14卷 184-187页

作者： yu-tuo Zhang yun Chi Chun-qing Hu School of Materials Science and Engineering Shenyang Ligong University Shenyang 110159 China Liaoning Academy of Governance Shenyang 110161 China

The microstructures and mechanical properties of Ti Al alloys are directly linked to micro-segregation which cannot be avoided during solidification. So a thorough understanding of the micro-segregation should be a great help to further enhance the mechanical properties of the cast products. Theoretical analysis and experiments have been used to predict the micro-segregation, but it is very difficult to observe and determine the dendritic segregation in the micro region. Phase-field method has been employed for the simulation of dendritic growth. However, due to the complicated quasi-sub regular solution model for Ti-45Al(at.%) alloy, the classic phase-field models have difficulty to deal with the free energy. In this work, a phase-field model by linking thermodynamic calculation was used to simulate solidification dendritic segregation of Ti-45 Al alloy for Liquid→Liquid+β(Ti). The free energies of solid phase and liquid phase for Ti-45 Al alloy were calculated by Thermo-Calc and then coupled with the phase-field equations. The simulation results show the dendritic morphology and Al content variations between liquid and growing solid phase for Ti-45 Al alloy. With the growth of the β(Ti), dendritic segregation is formed in the liquid and solid phases due to the solute partitioning and rejection into the liquid. As a result, the dendrite arms are depleted of Al element, while the inter-dendrites are enriched. The dendritic tip growth velocity decreases with the progress of solidification, whereas the segregation ratio increases.

关键词：阶段地模型树枝状的分离 Ti-45Al 免费精力等温的团结 TP391.92 A

Photoelectric properties ofβ-Ga_(2)O_(3) thin films annealed at different conditions

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Rare Metals 2022年第4期41卷 1375-1379页

作者： tuo Sheng Xing-Zhao Liu Ling-Xuan Qian Bo Xu Yi-yu Zhang School of Microelectronics and Solid-State Electronics University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054China

In this work,metal–semiconductor–metal solar-blind ultraviolet photoconductors were fabricated based on theβ-Ga_(2)O_(3) thin films which were grown on the c-plane sapphire substrates by molecular beam ***,the effects ofβ-Ga_(2)O_(3) annealing on both its material character-istics and the device photoconductivity were ***β-Ga_(2)O_(3) thin films were annealed at 800,900,1000,and 1100°C,***,the annealing time was fixed at 2 h,and the annealing ambients were oxygen,nitro-gen,and vacuum(4.9×10^(-4 )Pa),*** crys-talline quality and texture of theβ-Ga_(2)O_(3) thin films before and after annealing were investigated by X-ray diffraction(XRD),showing that higher annealing temperature can result in a weaker intensity of(402)diffraction peak and a lower device ***,the vacuum-annealed sam-ple exhibits the highest photoresponsivity compared with the oxygen-and nitrogen-annealed samples at the same annealing *** addition,the persistent photoconductivity effect is effectively restrained in the oxygen-annealed sample even with the lowest photoresponsivity.

关键词： Molecular beam epitaxy β-Ga_(2)O_(3)thin fllms Annealing Photoconductor