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Synergistically enhanced thermoelectric properties of Bi_(2)S_(3) bulk materials via Cu interstitial doping and BiCl_(3) alloying

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Rare Metals 2022年第3期41卷 931-941页

作者： Jun Guo Zi-Yuan Wang Yu-Ke Zhu Lin chen Jing Feng zhen-hua Ge Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

Bi_(2)S_(3)is composed of inexpensive and environ-mental friendliness elements,which has received extensive interests and been investigated as a promising mid-tempera-ture thermoelectric material for *** pure Bi_(2)S_(3)pos-sesses a high Seebeck coefficient and low thermal conductivity,its low electrical conductivity leads to a lowfigure of merit(ZT)*** this work,Bi_(2)S_(3)fabricated by solid-state melting combined with spark plasma sintering can significantly enhance the thermoelectric performance via introducing small amounts of Cu and BiCl_(3).Cu interstitial doping and Cl substitution on S site result in a large increase in electrical ***,the enhanced phonon scattering is derived from the point defects caused by element doping,the grain boundaries,and the small amount of sec-ondary phase,which leads to the low thermal ***,a high ZT value of 0.7 is obtained at 773 K and reaches a large average ZT of 0.36 in the temperature range from room temperature(RT)to 773 K for the Cu-interstitial-doped and BiCl_(3)-alloyed(Cu_(0.01)Bi_(2)S_(3)+0.175 mol%BiCl_(3))***,the mechanical properties of the Cu_(0.01)Bi_(2)S_(3)+0.175 mol%BiCl_(3)sample are lower than those of other Bi_(2)S_(3)samples,which stem from the weak chemical bonding strength.

关键词： Bismuth sulfide Cu–Cl co-doping Electrical conductivity Mechanical properties

Characterization of Multi-layer Weld Metal and Creep–Rupture Behavior of Modified 10Cr–1Mo Welded Joint

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Acta Metallurgica Sinica(English Letters) 2020年第6期33卷 808-820页

作者： Chang-zhen Zhang chen-Dong Shao Hai-Chao Cui hua-Li Xu Feng-Gui Lu Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The rupture behavior of the modified 10Cr–1Mo steel multi-layer welded joint is determined by the fine-grain zones of the weld metal adjacent to the fusion line during the long-term creep test at 620℃. The microstructures of multi-layer weld metal before and after the creep tests were characterized in detail, and its role in creep behavior was systematically investigated. Most grain boundaries of subgrains represented the low-angle boundaries in the weld metal adjacent to the fusion line both before and after the creep test. The widths of grains in the fine-grain zones were about 0.5–1 μm. The fracture morphology appeared as "wave" structure due to the cracking initiating from multi-layer grain boundaries in the fine-grain zones. Some W elements that melted into weld metal adjacent to the fusion line altered the thermodynamic and kinetic conditions of the Laves phase formation during long-term creep exposure. Laves phase particles mainly distributed along the grain boundaries due to the faster diffusion and segregation of Mo, W, and Si elements. Moreover, higher-density grain boundaries in the fine-grain zones led to easier nucleation and growth of Laves phase particles. Compared with other areas in the welded joint, the size of Laves phase particles in the fine-grain zones of the weld metal adjacent to the fusion line was the largest ones. The interface between Laves phase particles and the matrix acted as the nucleation site of creep micro-cavities. The creep micro-cavities grew up at the expense of fine-grain boundaries and even grew across the grain boundary deeply into adjacent grains, and then developed to cracks in the fine-grain zones.

关键词： 10Cr–1Mo Welded joint Fine grains Multi-layer Creep rupture

Exploring the Constrained Maximum Edge-weight Connected Graph Problem

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Acta Mathematicae Applicatae Sinica 2009年第4期25卷 697-708页

作者： zhen-ping Li Shi-hua Zhang Xiang-Sun Zhang Luo-nan chen School of Information Beijing Wuzi University Beijing 101149 China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Institute of Systems Biology Shanghai University Shanghai 200444 China Department of Electrical Engineering and Electronics Osaka Sangyo University Osaka 574-8530 Japan

Given an edge weighted graph, the maximum edge-weight connected graph （MECG） is a connected subgraph with a given number of edges and the maximal weight sum. Here we study a special case, i.e. the Constrained Maximum Edge-Weight Connected Graph problem （CMECG）, which is an MECG whose candidate subgraphs must include a given set of k edges, then also called the k-CMECG. We formulate the k-CMECG into an integer linear programming model based on the network flow problem. The k-CMECG is proved to be NP-hard. For the special case 1-CMECG, we propose an exact algorithm and a heuristic algorithm respectively. We also propose a heuristic algorithm for the k-CMECG problem. Some simulations have been done to analyze the quality of these algorithms. Moreover, we show that the algorithm for 1-CMECG problem can lead to the solution of the general MECG problem.

关键词： connected subgraph integer linear programming model network flow constraint Steiner network maximum edge weight, heuristic algorithm

Leaching of Copper and Zinc in a Garden Soil Receiving Poultry and Livestock Manures from Intensive Farming

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Pedosphere 2008年第1期18卷 69-76页

作者： HAO Xiu-zhen ZHOU Dong-Mei chen huai-Man DONG Yuan-hua State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) Graduate School of the Chinese Academy of Sciences Beijing 100049 (China)

The leaching characteristics of a garden soil may be greatly affected by application of poultry and livestock manures from intensive farming. Packed soil columns of a garden soil （CK） and the soils after respectively receiving 2% pig manure （PM）, chicken manure （CM）, and commercial organic manure （OM） were leached with 0.05 mol L^-1 Ca（NO3）2 and 0.01 mol L 1 EDTA solutions. The leachate EC （electric conductivity） values gradually increased at the beginning and then reached a stable value when the soil columns were leached with 0.05 mol L^-1 Ca（NO3）2 solution. The leachate EC values showed a peak-shape when leached with 0.01 mol L^-1 EDTA solution. In all the soil columns, the pH values of the leachates decreased with increase of displacement volumes when the Ca（NO3）2 solution was used. The total amounts of Cu and Zn eluted from the four soil columns were significantly correlated with the extracted soil Cu and Zn concentrations by 1.0 mol L^-1 NH4NO3, but were not correlated with the leachate dissolved organic carbon （DOC） contents. The Zn concentration in the leachate of the PM-treated soil column with 0.05 mol L^-1 Ca（NO3）2 solution was above the Quality Standard III for Ground Water of China （GB/T 14848-93, Zn 〈 1.0 mg L^-1）. When compared with 0.05 mol L^-1 Ca（NO3）2, the EDTA solution significantly accelerated Cu and Zn elutions in the manure-treated columns. This suggested that applying poultry and livestock manures from intensive farming to farmland might pose a threat to the groundwater quality.

关键词： copper garden soil leaching manures zinc

A New Kind of Biomaterials—Bullfrog Skin Collagen

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Chinese Chemical Letters 2003年第11期14卷 1146-1149页

作者： He LI Bai Ling LIU hua Lin chen Li zhen GAO chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041

Pepsin-soluble collagen was prepared from bullfrog skin and partially characterized. This study revealed interesting differences, such as molecular weight, amino acid composition, denaturation temperature (Td), in the frog skin collagen when compared to the known vertebrate collagens. This study gives hints that bullfrog skin can be a potential, safe alternative source of collagen from cattle for use in various fields.

关键词： Bullfrog skin collagen denaturation temperature.

Stochastic Optimal Control Problem in Advertising Model with Delay

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Journal of Systems Science & Complexity 2020年第4期33卷 968-987页

作者： chen Li WU zhen School of Science China University of Mining&TechnologyBeijing 100083China School of Mathematics Shandong UniversityJinan 250100China

This paper investigates the optimal control problem arising in advertising model with delay. The authors reformulate the problem in Hilbert space by stochastic evolution equation and consider the optimal control problem of controlled stochastic evolution system. The necessary and sufficient optimality conditions of the control are established. The proposed approach is different from most existing studies of optimal advertising policy problem with delay. These results are applied to the optimal advertising policy problem under two different structures and the optimal advertising strategies are obtained.

关键词： optimal stochastic Optimal

激光诱导荧光技术与地下水重金属原位检测应用进展

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岩矿测试 2025年第1期44卷 19-34页

作者：毛康薛家奇陈卓张华中国科学院地球化学研究所环境地球化学国家重点实验室贵州贵阳550081

对地下水重金属污染进行现场检测,是快速识别重金属种类和评价污染程度的重要手段。激光诱导荧光技术(LIF)利用特定荧光探针,在目标重金属存在下,通过激光诱导荧光探针产生/猝灭荧光,从而完成对重金属的识别和检测,具有快速甄别地下水... 详细信息

对地下水重金属污染进行现场检测,是快速识别重金属种类和评价污染程度的重要手段。激光诱导荧光技术(LIF)利用特定荧光探针,在目标重金属存在下,通过激光诱导荧光探针产生/猝灭荧光,从而完成对重金属的识别和检测,具有快速甄别地下水重金属污染特性和无损获取其价态的优势。本文在简述LIF检测重金属原理和LIF原位检测地下水重金属装备基础上,重点从荧光探针合成及其在重金属传感检测方法的构建上总结了基于不同荧光探针的LIF现场检测重金属的研究进展。目前可用于重金属检测的荧光探针包括以小分子探针、有机大分子和聚集诱导发光为主的有机荧光探针和以金纳米簇、量子点和金属有机框架材料为代表的纳米荧光探针。这些探针的合成及其对应的传感检测方法的构建表明LIF技术在地下水重金属检测中具有巨大优势。而针对地下水重金属检测的LIF设备研发方面的成果虽不如荧光传感检测方法丰富,但已研制出部分重金属的传感器和检测装备,表现出良好的应用前景。未来研究将会聚焦在地下水重金属主控因子识别和抗干扰技术研发、荧光探针合成与LIF检测方法构建、重金属传感部件和检测装备集成研制,以及检测技术标准化,为后续场地地下水典型重金属LIF检测技术的研究提供参考。

关键词：地下水重金属激光诱导荧光荧光探针现场检测

Nitrogen spraying affects seed Bt toxin concentration and yield in Bt cotton

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Journal of Integrative Agriculture 2021年第5期20卷 1229-1238页

作者： ZHANG Xiang ZHOU Ming-yuan LI Ya-bing LIU zhen-yu chen Yuan chen De-hua Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009P.R.China Cotton Research Institute Chinese Academy of Agricultural SciencesAnyang 455000P.R.China

Cotton bolls exhibit the lowest insecticidal efficacy among all organs of Bt cotton,which would ultimately affect the yield *** objective of this study was to investigate the effects of different urea concentrations on the seed Bt protein contents,seed cotton yield and the corresponding protein metabolism *** experiments were conducted during 2017–2018 cotton growing *** cultivars,Sikang 3(hybrid,SK3)and Sikang 1(conventional,SK1),were treated with six urea concentrations and their seed Bt protein contents were compared during boll formation *** urea spray concentration had a significant effect on the seed Bt toxin content and seed cotton *** of either 5 or 6%urea led to higher insecticidal protein contents and higher seed cotton yield for both ***,the highest amino acid and soluble protein contents,as well as GPT and GOT activities,and lower protease and peptidase activities were observed at the 5 to 6%urea *** positive correlations between the seed Bt toxin and amino acid contents,and between the seed Bt toxin content and GPT activities were *** lower boll worm number and hazard boll rate were also observed with the 5 to 6%urea treatments,which may be the reason why nitrogen spraying increased the seed cotton ***,our results suggested that the seed Bt toxin content and insect resistance were impacted markedly by external nitrogen application,and 5 to 6%urea had the greatest effect on insect resistance.

关键词： Bt cotton external nitrogen application urea concentration Bt toxin protein metabolism

Synthesis and characterization ofα-{3-[(2,3-dihydroxy) propoxy]propyl}-ω-butylpolydimethylsiloxanes

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Chinese Chemical Letters 2009年第6期20卷 729-732页

作者： Xiao Li Zhan zhen huan Luo Qing hua Zhang Bi chen Feng Qiu chen Department of Chemical and Biochemical Engineering. Zhejiang University Hangzhou 310027 China

Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-l,2-propanediol, and after subsequently alcoholyzed, α-{3-[（2,3-dihydroxy）propoxy]propyl}-ω- butyl-polydimethylsiloxanes with varying number of （（Si（CH3）2-O） unit were obtained. At each step, the produced compounds were carefully characterized. The results showed that each step was successfully carried out and target products were achieved.

关键词： Polydimethylsiloxane Anionic ring-opening polymerization Hydrosilylation Alcoholysis