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Enhancing thermoelectric performance in P-type Mg_(3)Sb_(2)-based Zintls through optimization of band gap structure and nanostructuring

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Journal of Materials Science & Technology 2024年第3期170卷 25-32页

作者： Yi-bo zhang Ji-sheng Liang Chengyan Liu Qi Zhou Zhe Xu Hong-bo Chen Fu-cong Li Ying Peng Lei Miao Guangxi Key Laboratory of Information Material Engineering Research Center of Electronic Information Materials and DevicesMinistry of EducationSchool of Material Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China Guangxi Key Laboratory for Relativity Astrophysics Center on Nanoenergy ResearchGuangxi Key Laboratory of Processing for Nonferrous Metal and Featured MaterialsSchool of Physical Science&TechnologyGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic TechnologySchool of Information and CommunicationGuilin 541004China

P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low ***,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE *** this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi *** a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi ***,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi *** synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.

关键词： Thermoelectric materials Band engineering Nanostructuring P-type Mg_(3)Sb_(2) Ag and Bi Co-doping

Modeling Regional and Local-scale Permafrost Distribution in Qinghai-Tibet Plateau Using Equivalent-elevation Method

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Chinese Geographical Science 2012年第3期22卷 278-287页

作者： LI Jing sheng Yu WU Jichun WANG Jie zhang bo YE Baisheng zhang Xiumin QIN Xiang State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Yunnan Institute of Water Resources and Hydropower Research Kunming 650228 China State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Qilian Shan Station of Glaciology and Ecologic Environment State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general permafrost-distribution patterns in regional and local-scale *** is found that the Gaussian curve―an empirical model describing the relation between variations of altitudinal permafrost lower limit (PLL) and latitude in the Northern Hemisphere―could be applied in regional-and local-scale areas in the Qinghai-Tibet Plateau in a latitude-sensitive interval of 30°-50°*** curve was then used to evaluate the latitudinal effect on permafrost distribution through transforming the latitudinal effect into a kind of altitudinal difference of *** study then calculated the local equivalent-elevation value by overlaying the altitudinal difference of PLL onto real elevation at a certain *** equivalent-elevation method was verified in an experimental subwatershed of the Qinghai-Tibet ***,feasibility of the method should be further tested in order to extend for future *** use of equivalent-elevation values can build a platform for comparing the regional general permafrost distribution in the plateau,and for basing further evaluations of local factors' effects on regional permafrost distribution.

关键词： equivalent-elevation method permafrost distribution permafrost lower limit (PLL) Gaussian curve plat- form function Qinghai-Tibet Plateau

Alleviation of Chromium Toxicity by Silicon Addition in Rice Plants

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Agricultural Sciences in China 2011年第8期10卷 1188-1196页

作者： ZENG Fan-rong ZHAO Fu-sheng QIU bo-yin OUYANG You-nan WU Fei-bo zhang Guo-ping Department of Agronomy College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310029P.R.China College of Agronomy Guizhou UniversityGuiyang 550025P.R.China China National Rice Research Institute Fuyang 310041P.R.China

The alleviatory effect of silicon （Si） on chromium （Cr） toxicity to rice plants was investigated using a hydroponic experiment with two Cr levels （0 and 100μmol L-1）,three Si levels （0,1.25,and 2.5 mmol L-1） and two rice genotypes,differing in grain Cr accumulation （Dan K5,high accumulation and Xiushui 113,low accumulation）.The results showed that 100μmol L-1 Cr treatment caused a marked reduction of seedling height,dry biomass,soluble protein content,and root antioxidant enzyme activity,whereas significantly increased Cr concentration and TBARS （thiobarbituric acid reactive substances） ***,the reductions of seedling height,dry biomass,and soluble content were greatly alleviated due to Si addition to the culture *** with the plants treated with Cr alone,Si addition markedly reduced Cr uptake and translocation in rice *** significant differences were observed between the two Si treatments （1.25 and 2.5 mmol L-1） in shoot Cr concentration and Cr translocation *** the treatment of 100μmol L-1 Cr＋2.5 mmol L-1 Si,higher root Cr concentration but lower shoot Cr concentration and Cr translocation factor were observed in Dan K5 than those in Xiushui 113,indicating that the beneficial effect of Si on inhibiting Cr translocation was more pronounced in Dan K5 than in Xiushui *** addition also alleviated the reduction of antioxidative enzymes （superoxide dismutase （SOD） and ascorbate peroxidase （APX） in leaves;catalase （CAT） and APX in roots） and the increase of TBARS content in the Cr-stressed ***,the beneficial effects of Si on activities of antioxidative enzymes under Cr stress were *** highest activities of SOD,POD （guaiacol peroxidase）,CAT,and APX in leaves occurred in the treatment of 100μmol L-1 Cr＋2.5 mmol L-1 Si for Xiushui 113 and in the treatment of 100μmol L-1 Cr＋1.25 mmol L-1 Si for Dan *** beneficial effect of Si on alleviating oxidative stress was much more pronounced in Dan K5 than

关键词： antioxidant enzyme chromium lipid peroxidation Oryza sativa L. silicon translocation

Minimum Amount of Extracting Solvent of (A_(1)A_(2)…A_(t−1))/(A_(2)A_(3)…A_(t)) Separation When Using Non-barren Extracting Solvent

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Chinese Journal of Chemistry 2014年第10期32卷 1022-1028页

作者： Fu-Xiang Cheng sheng Wu Song-Ling Wang bo zhang Yan Liu Chun-sheng Liao Chun-Hua Yan Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Lab on Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871China China Minmetals(Beijing)Research Institute of RE Co. LtdBeijing 100085China

Hyperlink extraction technology,by virtue of its remarkable advantage of decreasing the use of chemicals in multi-component separation,has been extensively employed in rare earth separation industry in *** hyperlink processes,non-barren extracting solvent and scrubbing agent solution which contain the component(s)involved in starting feed are employed in order to save both alkali for saponification and acid for *** amount of extracting solvent(denoted as S_(min))and that of scrubbing agent solution(denoted as W_(min))are important parameters to determine the consumption amounts of alkali and acid for a given countercurrent extraction *** article therefore discusses the influence of using non-barren extracting solvent and scrubbing agent solution on S_(min) and W_(min) of an(A_(1)A_(2)…A_(t−1))/(A_(2)A_(3)…A_(t))*** equations for S_(min) and W_(min) are derived,and the variation of the composition of final raffinate as well as that of final extract are determined,which will provide a valuable guidance for the design of hyperlink extraction processes of multi-component separation,such as rare earths separation.

关键词： minimum amount of extracting solvent rare earths hyperlink process multi-component separation

Total synthesis of proposed structures ofjiangrines C and D

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Science China Chemistry 2016年第9期59卷 1205-1210页

作者： Zhijiang zhang bo Liu Key Laboratory of Green Chemistry & Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 China State Key Laboratory of Natural Medicines China Pharmaceutical University Nanjing 210009 China

On the basis of the proposed structures of jiangrines C and D, a synthetic strategy was initiated from D-glyceraldehyde acetonide,a readily available chiral material. Through a linear seven-step synthesis, the target molecules were accomplished. However, all characteristic data of the synthetic 3 and 4 were found to be different from those of natural jiangrines C and D. Accordingly, the molecular structures of jiangrines should be revised and a possible molecular skeleton for them was proposed.

关键词： pyrrole alkaloid jiangrine total synthesis

A Note about Minimal Hypercones

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Acta Mathematica Sinica,English Series 2021年第11期37卷 1794-1802页

作者： Yong sheng zhang School of Mathematical Sciences&IAS Tongji UniversityShanghai 200092P.R.China

This short note is concerned with a measure version criterion for hypersurfaces to be *** natural flows and associated reflections for many minimal hypercones,including minimal isoparametric hypercones and area-minimi... 详细信息

关键词： Minimal hypercone measure invariant flow foliation

On Coleman Automorphisms of Finite Nilpotent Groups by Cyclic Groups

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Acta Mathematica Sinica,English Series 2016年第12期32卷 1459-1464页

作者： Jin Ke HAI sheng bo GE College of Mathematics and Statistics Qingdao University

Let G be a finite group and let N be a nilpotent normal subgroup of G such that G/N is cyclic. It is shown that under some conditions all Coleman automorphisms of G are inner. Interest in such automorphisms arose from... 详细信息

关键词： Coleman automorphism the normalizer property nilpotent group

Efficient Concurrent L1-Minimization Solvers on GPUs

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Computer Systems Science & Engineering 2021年第9期38卷 305-320页

作者： Xinyue Chu Jiaquan Gao bo sheng Jiangsu Key Laboratory for NSLSCS School of Computer and Electronic InformationNanjing Normal UniversityNanjing 210023China Department of Computer Science University of Massachusetts BostonMA 02125USA

Given that the concurrent L1-minimization(L1-min)problem is often required in some real applications,we investigate how to solve it in parallel on GPUs in this ***,we propose a novel self-adaptive warp implementation of the matrix-vector multiplication(Ax)and a novel self-adaptive thread implementation of the matrix-vector multiplication(ATx),respectively,on the *** vector-operation and inner-product decision trees are adopted to choose the optimal vector-operation and inner-product kernels for vectors of any ***,based on the above proposed kernels,the iterative shrinkage-thresholding algorithm is utilized to present two concurrent L1-min solvers from the perspective of the streams and the thread blocks on a GPU,and optimize their performance by using the new features of GPU such as the shuffle instruction and the read-only data ***,we design a concurrent L1-min solver on multiple *** experimental results have validated the high effectiveness and good performance of our proposed methods.

关键词： Concurrent L1-minimization problem dense matrix-vector multiplication fast iterative shrinkage-thresholding algorithm CUDA GPUs

Subgroup Analysis for Longitudinal Data via Semiparametric Additive Mixed Effects Model

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Journal of Systems Science & Complexity 2023年第5期36卷 2155-2185页

作者： bo Xiaolin zhang Weiping Department of Statistics and Finance University of Science and Technology of ChinaHefei 230026China

This paper proposed a general framework based on semiparametric additive mixed effects model to identify subgroups on each covariate and estimate the corresponding regression functions simultaneously for longitudinal data,thus it could reveal which covariate contributes to the existence of subgroups among population.A backfitting combined with k-means algorithm was developed to detect subgroup structure on each covariate and estimate each semiparametric additive component across subgroups.A Bayesian information criterion is employed to estimate the actual number of *** efficacy and accuracy of the proposed procedure in identifying the subgroups and estimating the regression functions are illustrated through numerical *** addition,the authors demonstrate the usefulness of the proposed method with applications to PBC data and Industrial Portfolio's Return data and provide meaningful partitions of the populations.

关键词： Additive model backfitting mixed effects subgroup identification