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Optimized the vanadium electrolyte with sulfate-phosphoric mixed acids to enhance the stable operation at high-temperature

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Frontiers of Chemical Science and Engineering 2024年第2期18卷 13-26页

作者： Ling Ge Tao Liu yimin Zhang Hong Liu School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control Wuhan University of Science and TechnologyWuhan 430081China Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium Resource Wuhan University of Science and TechnologyWuhan 430081China School of Resource and Environmental Engineering Wuhan University of TechnologyWuhan 430070China

Herein, the influence of the concentration design and comprehensive performance of the sulfate-phosphoric mixed acid system electrolyte is investigated to realize an electrolyte that maintains high energy density and stable operation at high temperatures. Static stability tests have shown that VOPO4 precipitation occurs only with vanadium(V) electrolyte. The concentration of vanadium ion of 2.0–2.2 mol·L^(–1), phosphoric acid of 0.10–0.15 mol·L^(–1), and sulfuric acid of 2.5–3.0 mol·L^(–1) are suitable for a vanadium redox flow battery in the temperature range from –20 to 50 ℃. The equations for predicting the viscosity and conductivity of electrolytes are obtained by the response surface method. The optimized electrolyte overcomes precipitation generation. It has 2.8 times higher energy density than the non-phosphate electrolyte, and a coulomb efficiency of 94.0% at 50 ℃. The sulfate-phosphoric mixed acid system electrolyte promotes the electrode reaction process, increases the current density, and reduces the resistance. This work systematically optimizes the concentrations of composition of positive and negative vanadium electrolytes with mixed sulfate-phosphoric acid. It provides a basis for the different valence states and comprehensive properties of sulfate-phosphoric mixed acid system vanadium electrolytes under extreme environments, guiding engineering applications.

关键词： all vanadium redox flow battery mixed-acid vanadium electrolyte concentration optimization response surface methodology high-temperature stability

Enhancing the electrocatalytic performance of nitrate reduction to ammonia by in-situ nitrogen leaching

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Chinese Chemical Letters 2024年第2期35卷 564-569页

作者： Mimi Fu Yini Mao Hua wang Wei Luo yimin Jiang Wei Shen Ming Li Rongxing He College of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China

Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by the lack of highly reactive and selective electrocatalysts .Herein, for the first time, nickel foam supported Co_(4) N was designed as a high-performance NITRR catalyst by an in-situ nonmetal leaching-induced *** the optimal potential, the Co_(4) N/NF catalyst achieves ultra-high Faraday efficiency and NH_(3) selectivity of 95.4% and 99.4%, *** situ X-ray absorption spectroscopy (XAS), together with other experiments powerfully reveal that the nitrogen vacancies produced by nitrogen leaching are stable and play a key role in boosting nitrate reduction to *** calculations confirm that Co_(4) N with abundant nitrogen vacancies can optimize the adsorption energies of NO_(3)^(-) and intermediates, lower the free energy (Δ G ) of the potential-determining step (*NH_(3) to NH_(3) ) and inhibit the formation of N-containing *** addition, we also conclude that the nitrogen vacancies can stabilize the adsorbed hydrogen, making H_(2) quite difficult to produce, and lowering ΔG from *NO to *NOH, which facilitates the selective reduction of *** study reveals significant insights about the in-situ nonmetal leaching to enhance the NITRR activity.

关键词： Co4N Nitrate reduction In-situ nonmetal leaching Nitrogen vacancy Mechanism

Synergy methodology for multi-objective operational control of reservoirs in Yellow River basin

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Science China(Technological Sciences) 2004年第Z1期47卷 212-223页

作者： HUANG Qiang CHANG Jianxia wang yimin PENG Shaoming Hydraulic and Hydrauelectric Institute Xi'an University of Technology Xi'an 710048 China Hydraulic and Hydrauelectric Institute Xi'an University of Technology Xi'an 710048 China Hydraulic and Hydrauelectric Institute Xi'an University of Technology Xi'an 710048 China Hydraulic and Hydrauelectric Institute Xi'an University of Technology Xi'an 710048 China

This paper presents an application of synergy methodology to a multi- objective operational control of reservoirs. This methodology enables a comprehensive consideration of multi-objectives which may be conflicting and non commensurate such as municipal and industrial water supply, flood protection, and hydroelectric power generation etc. On the basis of the synergy theory, a harmony degree model of sub- system was established to describe the coordination magnitude. Combined with information entropy, a harmony degree entropy was proposed to determine the water resources evolvement direction. While implementing the control, an initial scheme for reservoir operation was obtained from simulation first, then control was carried out according to the harmony degree and harmony degree entropy by applying synergy theory. The application of the methodology to reservoir system in the Yellow River was reported in this paper through a case study.

关键词： reservoir system, operational control, synergy theory, harmony degree, harmony degree entropy.

Clinical factors associated with composition of lung microbiota and important taxa predicting clinical prognosis in patients with severe community-acquired pneumonia

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Frontiers of Medicine 2022年第3期16卷 389-402页

作者： Sisi Du Xiaojing Wu Binbin Li yimin wang Lianhan Shang Xu Huang Yudi Xia Donghao Yu Naicong Lu Zhibo Liu Chunlei wang Xinmeng Liu Zhujia Xiong Xiaohui Zou Binghuai Lu Yingmei Liu Qingyuan Zhan Bin Cao China-Japan Friendship Hospital National Clinical Research Center for Respiratory DiseasesNational Center for Respiratory MedicineClinical Center for Pulmonary InfectionsCapital Medical UniversityBeijing 100029China Institute of Respiratory Medicine Chinese Academy of Medical SciencesPeking Union Medical CollegeBeijing 100029China Department of Pulmonary and Critical Care Medicine Center for Respiratory DiseasesChina-Japan Friendship HospitalBeijing 100029China Beijing University of Chinese Medicine Beijing 100029China Beijing Luhe Hospital Beijing 101100China Tsinghua University–Peking University Joint Center for Life Sciences Beijing 100084China

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia(SCAP).We prospectively enrolled consecutive SCAP patients admitted to *** was performed at bedside within 48 h of ICU admission,and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage *** primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following ***-seven patients were *** permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota(R2=0.033;P=0.018),followed by acute kidney injury(AKI;R2=0.032;P=0.011)and plasma MIP-1βlevel(R2=0.027;P=0.044).Random forest identified that the families Prevotellaceae,Moraxellaceae,and Staphylococcaceae were the biomarkers related to the positive bacteria lab test *** Cox regression showed that the increase inα-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical *** positive bacteria lab test results,AKI,and plasma MIP-1βlevel were associated with patients’lung microbiota composition on ICU *** families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.

关键词： severe community-acquired pneumonia lung microbiota clinical improvements 7-category ordinal scale Prevotellaceae

Realtime observation of “spring fracture” like AlGaN/GaN HEMT failure under bias

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Science China(Information Sciences) 2024年第1期67卷 303-305页

作者： Qing ZHU Zhenni wang Yuxiang WEI Ling YANG Xiaoli LU Jiejie ZHU Peng ZHONG yimin LEI Xiaohua MA School of Microelectronics Xidian University State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology Xidian University School of Advanced Materials and Nanotechnology Xidian University

The AlGaN/GaN HEMTs have been considered promising candidates for high-frequency and high-power applications,while the reliability issues greatly limit the commercialization of AlGaN/GaN HEMTs. In the past, the research on the reliability of devices was often based on Raman spectroscopy, cathodoluminescence, and TEM after failure of the devices, which is often considered to be the laborious and complicated “archaeological” kind of analysis [1].

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Circulation Background and Genesis Mechanism of a Cold Vortex over the Tibetan Plateau during Late April 2018

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Advances in Atmospheric Sciences 2024年第6期41卷 1201-1216页

作者： Duming GAO Jiangyu MAO Guoxiong WU yimin LIU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Institute of Plateau MeteorologyChina Meteorological AdministrationChengdu 610072China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China

A cold vortex occurred over the northeastern Tibetan Plateau(TP)on 27 April 2018 and subsequently brought excessive rainfall to the spring farming area in southern China when moving *** study investigates the genesis mechanism of the cold TP vortex(TPV)by diagnosing reanalysis data and conducting numerical *** demonstrate that the cold TPV was generated in a highly baroclinic environment with significant contributions of positive potential vorticity(PV)forcing from the tropopause and diurnal thermodynamic impact from the *** a positive PV anomaly in the lower stratosphere moved towards the TP,the PV forcing at the tropopause pushed the tropospheric isentropic surfaces upward,forming isentropic-isplacement ascent and reducing static stability over the *** descent of the tropopause over the TP also produced a tropopause folding over the northeastern TP associated with a narrow high-PV column intruding downwards over the TPV genesis site,resulting in ascending air in the free ***,in conjunction with the descending air in the valley area during the night,produced air stretching just at the TPV genesis *** the surface cooling at night increased the surface static stability,the aforementioned vertical air-stretching thus converted the produced static stability to vertical ***,the cold TPV was generated over the valley at night.

关键词： tropopause PV forcing air column stretching static stability vertical vorticity

Coalbursts in China: Theory, practice and management

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 1-25页

作者： Yishan Pan yimin Song Hao Luo Yonghui Xiao Institute of Disaster Rock Mechanics Liaoning UniversityShenyang110036China School of Civil Engineering North China University of TechnologyBeijing100144China College of Computer Science Liaoning UniversityShenyang110036China School of Physics Liaoning UniversityShenyang110036China

Coalburst is one of the most serious disasters that threaten the safe production of coal mines, and this disaster is particularly serious in China. This paper presents an overview of coalbursts in China since 1980s. From the "stress and energy" and "regional and local" perspectives, the achievements in the theory, practice and management of coalbursts in China are systematically summarized. A theoretical system of coalbursts has been formed to reveal the deformational behavior of coalbursts and explain the mechanism of coalbursts. The occurrence conditions of coalbursts are put forward and the critical stress is obtained. The stress index method for risk evaluation of coalbursts before mining is proposed, and the deformation localization prediction method of coalbursts is put forward. The relationship between energy release and absorption in the process of coalbursts is found, and the prevention and control methods of coalbursts, including the regional method, the local method and support, are presented. The safety evaluation index of coalburst prevention and control is put forward. The integrated prevention and control method for coal and gas outbursts is proposed. The prevention and control technology and equipment of coalbursts have also been developed. Amongst them, the distribution law of the critical stress in China coalburst mines is discovered. The technology and equipment for monitoring, prevention and control of coalbursts, as well as for integrated prevention and control of combined coalbursts and other disasters, have been developed. The energy-absorbing and coalburst-preventing support technology for roadways is invented, and key engineering parameters of coalburst prevention and control are pointed out. In China, coalburst prevention and control laws and standards have been developed. Technical standards for coalbursts are formulated, statute and regulations for coal mines are established, and regulatory documents are promoted.

关键词： Coalbursts Rockbursts Dynamic disaster Energy-absorbing support Monitoring and early warning

Profitability and Productivity of the Chinese Textile Industry

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China & World Economy 2010年第5期18卷 1-21页

作者： yimin Zhang Tianmu wang China Europe International Business School Shanghai China

This paper considers the cost structure, profitability and productivity of the Chinese textile industry and estimates the impacts of RMB appreciation on this industry. Using data for 1999-2006, we found that the industry has suffered from very low profit margins and returns on capital. Because input prices have been increasing, particularly since 2001, generating profits has become more difficult for the industry. Nevertheless, the industry achieved substantial productivity growth over the period examined. Although at an inadequate level the proJ^tability of the industry did show some signs of improvement. As long as this trend continues, the industry could obtain a decent level of profitability. Since 2005, however, the industry has faced a new challenge： the appreciation of the RMB. Based on 2006 data, we estimated the maximum rate of RMB appreciation that the industry would be able to sustain to be approximately 5percent a year.

关键词： Chinese textile industry productivity profitability RMB exchange rates

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乾隆皇帝御笔书法中的代笔现象初探

故宫博物院院刊 2022年第12期248卷 13-33,138页

作者：王亦旻故宫博物院书画部

本文是对故宫博物院所藏乾隆代笔书法的初步整理和研究。在乾隆一生留下的大量书法作品中,代笔之作所占比重并不高,但却涵盖了其各时期、各方面的书写内容,以及各种形制的作品,对于今天全面认识乾隆君臣在书法创作方面的互动关系具有重... 详细信息

本文是对故宫博物院所藏乾隆代笔书法的初步整理和研究。在乾隆一生留下的大量书法作品中,代笔之作所占比重并不高,但却涵盖了其各时期、各方面的书写内容,以及各种形制的作品,对于今天全面认识乾隆君臣在书法创作方面的互动关系具有重要意义。本文尝试纠正前人在此问题上的模糊认识,使人们对乾隆的代笔书法形成更准确的界定,进而选取各时期较典型的代笔和亲笔作品进行比对,对一些可能的代笔大臣加以考辨。

关键词：乾隆书法词臣代笔张照于敏中董诰