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Thermochemistry on coordination behavior of samaric chloride hydrate with diethylammonium diethyldithiocarbamate

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Rare metals 2004年第3期23卷 203-208页

作者： JIAOBaojuan RENYixia CHENSanping GAOShengli ZHAOFengqi SHIQizhen DepartmentofChemistry ShaanxiKeyLaboratoryofPhysico-InorganicChemistryNorthwestUniversityXi＇an710069China xi＇anModemChemistryresearch{2. Xi＇an710072China DepartmentofChemistry ShaanxiKeyLaboratoryofPhysico-InorganicChemistryNorthwestUniversityXi＇an710069China

The complex of samaric chloride lower hydrate with diethylammoniumdiethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2.tmosphere. The title complex was identified as Et_2.H_2.Sm(S_2.NEt_2._4] by chemical and elementalanalyses, the bonding characteristics of which was characterized by IR. The enthalpies of solutionof samaric chloride hydrate and D-DDC in absolute alcohol at 2.8.15 K and the enthalpies change ofliquid-phase reaction of formation for Et_2.H_2.Sm(S_2.NEt_2._4] at different temperatures weredetermined by mi-crocalorimetry. On the basis of experimental and calculated results, threethermodynamic parameters (the activation enthalpy, the activation entropy, and the activation freeenergy), the rate constant, and three kinetic parameters (the apparent activation energy, thepre-exponential constant, and the reaction order) of liquid phase reaction of formation wereobtained. The enthalpy change of the solid-phase title reaction at 2.8.15 K was calculated by athermochemical cycle.

关键词： inorganic chemistry thermochemistry microcalorimetric method samaricchloride hydrate diethylammonium diethyldithiocarbamate (D-DDC)

A research on the Joining of SiC Composite to 40 Cr Steel

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Journal of University of Science and Technology Beijing 2001年第4期8卷 280-282页

作者： Chengchang Jia, Jianxin Chu, Qingshan Zhao 1) Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 2. Beijing nonferrous {2.s {2. institute, Beijing 100081, China Univ Sci & Technol Beijing Beijing 100083 Peoples R China Beijing nonferrous Met Res Inst Beijing 100081 Peoples R China

SiC composites and 40 Cr Steels were joined with Ag-Cu-Ti solder in order to develop a new method of joining ceramics to metal. Effects of solder component and process parameters on the joining strength were investigated. The results show that some chemical reactions occur on the jointing interface between ceramics and metal. Higher joining strength is achieved when titanium is 0.2. (mass fraction) in the solder. The thickness of solder also affects the joining characteristics, and 0.2.0.3 mm. thickness of solder is the most suitable.

关键词： ceramics metal joint sintering SiC composites Ag-Cu-Ti solder

Status of Fabricated Products of Titanium in China

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Rare metals 1989年第4期9卷 67-73页

作者： Li Qingyun Yin Weihong northwest institute for{2. metals research,Baoji{2. metals Works,P.O.Box 71,Baoji,Shaanxi,China 宝鸡有色金属厂陕西宝鸡

China has had 30 years experience in titanium research,development,production and appli-cation so *** was really a rough and bumpy road for developing Ti working industry,however,since a large amount of work was done and great many achievements were obtained by the scien-tists and engineers in this field,a firm base of Ti working industry has been established in China *** since the beginning of 1980 s,it has been developed to a new *** these bases,afavourable condition to speed up the development of Ti working industry arises in China.

关键词： Ti Status of Fabricated Products of Titanium in China

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L1/2.regularization

Science China(Information Sciences) 2010年第6期53卷 1159-1169页

作者： XU ZongBen 1 , ZHANG Hai 1,2., WANG Yao 1 , CHANG xiangYu 1 & LIANG Yong 3 1 institute of Information and System Science, xi'an Jiaotong University, xi'an 710049, China 2.Department of Mathematics, northwest University, xi'an 710069, China 3 University of Science and Technology, Macau 999078, China 1. institute of Information and System Science Xi’an Jiaotong University Xi’an 710049 China2. Department of Mathematics Northwest University Xi’an 710069 China3. University of Science and Technology Macau 999078 China

In this paper we propose an L1 /2.regularizer which has a nonconvex *** L 1/2.regularizer is shown to have many promising properties such as unbiasedness, sparsity and oracle properties.A reweighed iterative algorithm is proposed so that the solution of the L 1/2.regularizer can be solved through transforming it into the solution of a series of L 1 *** solution of the L 1/2.regularizer is more sparse than that of the L 1 regularizer, while solving the L 1/2.regularizer is much simpler than solving the L 0 *** experiments show that the L 1/2.regularizer is very useful and efficient, and can be taken as a representative of the Lp(0 < p < 1) regularizer.

关键词： machine learning variable selection regularizer compressed sensing

Stable carbon isotope composition and intrinsic water use efficiency in plants along an altitudinal gradient on the eastern slope of Yulong Snow Mountain, China

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Ecological Processes 2024年第2期13卷 218-230页

作者： Feng Jiang Tao Pu Zi-Jing Xue Yan-Wei Ma xiao-Yi Shi Fu-xi Shi College of Geography and Environmental Sciences Zhejiang Normal University Yulong Snow Mountain Glacier and Environment Observation and research Station/State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of Forestry Jiangxi Agricultural University

Background Stable carbon isotope composition(δ13Cp) can be used to estimate the changes in intrinsic water use efficiency（iWUE） in plants,which helps us to better understand plants' response strategies to climate *** study focused on the variations in δ13Cpand iWUE for the different life-form plants（i.e.,herbs,shrubs,and trees）along an altitudinal gradient（3300,3600,3900,4100,4300,and 4500 m） on the eastern slope of Yulong Snow Mountain,southeastern margin of the Qinghai-Tibet *** response mechanisms of δ13Cpand iWUE for different life-form plants to altitude were thoroughly analyzed in this mountain *** The δ13Cpvalues of plants on the eastern slopes of Yulong Snow Mountain ranged from-30.4‰to-2..55‰,with a mean of-2..02.,indicating a dominance of *** δ13Cpand iWUE values varied among different life-form plants in the order of herbs> shrubs> trees,particularly in 3600,3900,and 4300 ***δ13Cpand iWUE values for herbs and shrubs increased with altitude and were mainly controlled by air *** two parameters for trees exhibited a trend of initial decrease followed by an increase with *** 3900 m,the δ13Cpand iWUE values decreased with altitude,influenced by soil ***,above 3900 m,the two parameters increased with altitude,mainly regulated by air *** addition,iWUE was positively correlated with leaf P content but negatively correlated with leaf N:P ratio,especially for herbs and trees,suggesting that P plays a key role in modulating iWUE in this *** The diffe rentiated responses of water availability for different life-form plants to a higher altitudinal gradient are regulated by air temperature,soil moisture,and leaf P content in the Yulong Snow *** results provide valuable insights into understanding the wate r-carbon relationships in high-altitude ecosystems.

关键词： Stable carbon isotope Water use efficiency Altitude Life form Yulong Snow Mountain

Impact of land-use change on hydrological processes in the Maying River basin, China

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Science China Earth Sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3, ZHANG Yu2. LIU Guimin2.& CHEN Lin3 1. institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China 2. Cold and Arid Regions Environmental and Engineering research institute, Chinese Academy of Sciences, Lanzhou 730000, China 3. Resource and Environment School, Lanzhou University, Lanzhou 730000, China 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of China. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest China, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 2..12., a base flow decline of 35.32., a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 2..87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62.-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

An Overview of Mineral Processing in China

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Rare metals 2001年第2期20卷 69-73页

作者： Quanyuan Chen, Jingshen Zhang, Dianzuo Whng (Changsha research institute of Mining and{2.lurgy, Changsha 410012. China General research institute for nonferrous{2.s, Beijing 100088, China) Changsha Res Inst Min & Met Changsha 410012 Peoples R China Gen Res Inst nonferrous Met Beijing 100088 Peoples R China

The latest progress in mineral processing in China is described. It is also pointed out that the existing technology can not meet the needs of economic development. The combined challenges of poor resources, economical benefits and environmental pollution issues require further research to upgrade the separation efficiency economically. The methods of mineral processing should play a more important part in waste treatment such as wastewater treatment, the remediation of contaminated soil and the recycling of wastes. Biomineral technology will be utilised in the near future.

关键词： mineral processing biomineral technology comminution ore waste treatment

MICROSTRUCTURE AND CORROSION BEHAVIOR OF 70Cu-30Ni WELDED PIPE

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中国有色金属学会会刊：英文版 1995年第2期5卷 88-92页

作者： Wang,Jihui Jiang, xiaoxia Li,Shizhuo({2. of metal {2., Chinese Academy of Sciences,Shengyang 110015) Chinese Acad of Sciences Shengyang China

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关键词： cupronickel alloy welding corrosion behavior

Using soil surface gray level to determine surface soil water content

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Science China Earth Sciences 2010年第10期53卷 1527-1532页

作者： ZHU YuanJun1,2.WANG YunQiang1,2.& SHAO MingAn1,2.1 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau,institute of Soil and Water Conservation,northwest A & F University,Yangling 712.00,China 2.institute of Soil and Water Conservation,Chinese Academy of Sciences & Ministry of Water Resources,Yangling 712.00,China 1. State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Institute of Soil and Water Conservation Northwest A & F University Yangling 712100 China2. Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources Yangling 712100 China

How to determine surface soil water content(SWC) quickly and accurately is fundamental in studying eco-hydrological processes and their *** we use laboratory experiments to determine surface SWC using soil surface gray level(SGL) values.A negatively exponential relationship exists between SGL and SWC,i.e.,SGL increases with the decrease of *** can be estimated based on initial SGL value(surface gray level when SWC=0),SWC,and a surface roughness coefficient characterized by mean soil particle *** variation range of SGL was larger than that of SWC,indicating that changes in SWC were enhanced in SGL,and that SGL would thus be sensitive to changes in soil *** the 95% confidence level,SWC can be determined by using the relationship between SWC and SGL established by the *** determination of SWC has a high precision when SWC was between dry and saturated.

关键词： Loess Plateau soil water remote sensing surface roughness