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A complex variable meshless method for fracture problems

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 46-59页

作者： CHENG Yumin1 & LI Jiuhong2.1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai university, Shanghai 2.0072. china 2. {2. of Building Engineering, xi’an university of Technology, xi’an 710048, china Shanghai Institute of Applied Mathematics Mechanics Shanghai University Shanghai 200072 China department of Building Engineering Xi’an University of Technology Xi’an 710048 China

Based on the moving least-square (MLS) approximation, the complex variable moving least-square approximation (CVMLS) is discussed in this paper. The complex variable moving least-square approximation cannot form ill-conditioned equations, and has greater precision and computational efficiency. Using the analytical solution near the tip of a crack, the trial functions in the complex variable moving least-square approxi- mation are extended, and the corresponding approximation function is obtained. And from the minimum potential energy principle, a complex variable meshless method for fracture problems is presented, and the formulae of the complex variable meshless method are obtained. The complex variable meshless method in this paper has greater precision and computational efficiency than the conventional meshless method. Some examples are given.

关键词： moving least-square approximation, complex variable moving least-square approximation, meshless method, complex variable meshless method, fracture.

Determination of Kinetic Parameters and Metal Ions in Urea-Urease System Based on the Biochemical Reaction Heat Induced Laser Beam Deflection

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Chinese Chemical Letters 2000年第2期11卷 157-160页

作者： Hong Tao YAN xiao Yun ZHU (department of Chemistry, northwest university, xian{2.) NW Univ xian Dept Chem Xian 710069 Peoples R China

A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper. With the method, the Michaelis constant (K-m) of urease and apparent inhibition constant (K-i) of some metal ion inhibitors were measured respectively. This method was also used for the quantitative determination of metal ions with satisfactory result.

关键词： urease kinetic parameter metal ions determination laser beam deflection

Mixed-valence copper coordination polymers based on CuSCN or CuN_(3) as bridging motifs

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Science china Chemistry 2005年第z1期48卷 41-44页

作者： FAN Guang,GAO Shengli,CHEN Sanping,ZENG Minghua & xiE Gang department of Chemistry,northwest {2.,xi’an 710069,china department of Chemistry,Guangxi Normal {2.,Guilin 541000,china NW Univ xian Dept Chem Xian 710069 Peoples R China Guangxi Normal Univ Dept Chem Guilin 541000 Peoples R China

Two novel mixed valence copper coordination polymers, [Cu(2.pac)2.CuN3)(H2.)]n (1) and [Cu(2.pac)2.CuSCN)2.n (2., have been prepared through hydrothermal synthesis and analyzed for structure determination, which exhibit two- and three-dimensional structures respectively. In complex (1), zigzag chains of [CuN3]n running parallel to the c direction are interconnected by Cu(2.ac)2.to form a two-dimensional layer structure. In complex (2., the arrangement of μ-1,1,3 bridging thiocyanate ligand leads to the formation of ten-membered Cu-SCN- Cu-S-Cu-NCS rings, and each Cu atom is further linked by Cu(2.pac)2.to afford a three-dimensional configuration.

关键词： hydrothermal synthesis, crystal structure, 2.pyrazinecarboxylic acid, coordination polymer.

A hybrid mean value related to the Dedekind sums and Kloosterman sums

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Science china Mathematics 2010年第9期53卷 2543-2550页

作者： ZHANG WenPeng & LIU YanNi department of Mathematics,northwest {2.,xi’an 71012.,china 1. department of Mathematics Northwest University Xi’an 710127 China

The main purpose of this paper is using the properties of character sum and the analytic method to study a hybrid mean value problem related to the Dedekind sums and Kloosterman sums,and give some interesting mean val... 详细信息

关键词： Dedekind sum Kloosterman sums Hybrid mean value asymptotic formula identity

Gorenstein projective modules over rings of Morita contexts

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Science china Mathematics 2024年第11期67卷 2453-2484页

作者： Qianqian Guo Changchang xi School of Mathematical Sciences Capital Normal University School of Mathematical Sciences Laboratory of Mathematics and Complex Systems(Ministry of Education of China)Beijing Normal University School of Mathematics and Statistics Shaanxi Normal University

Under semi-weak and weak compatibility conditions of bimodules,we establish necessary and sufficient conditions of Gorenstein-projective modules over rings of Morita contexts with one bimodule homomorphism *** extends greatly the results on triangular matrix Artin algebras and on Artin algebras of Morita contexts with two bimodule homomorphisms zero in the literature,where only sufficient conditions are given under a strong assumption of compatibility of *** application is provided to describe Gorenstein-projective modules over noncommutative tensor products arising from Morita *** results are proved under a general setting of noetherian rings and modules instead of Artin algebras and modules.

关键词： Gorenstein-projective module noetherian ring noncommutative tensor product totally exact complex weakly compatible bimodule

Role of biochar in raising blue carbon stock capacity of salt marshes

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Pedosphere 2024年第1期34卷 19-22页

作者： Yuzhou HUANG xi xiAO Ocean College Zhejiang UniversityZhoushan 316021China Key Laboratory of Marine Ecological Monitoring and Restoration Technologies of the Ministry of Natural Resources of china Shanghai 201306China Donghai Laboratory Zhoushan 316021China Ocean Academy Zhejiang UniversityZhoushan 316021China Key Laboratory of Watershed Non-point Source Pollution Control and Water Eco-security of Ministry of Water Resources College of Environmental and Resources SciencesZhejiang UniversityHangzhou 310058China

Salt marshes are an important blue carbon ecosystem, with surprisingly fast carbon accumulation rates that are 40 times higher than those of terrestrial forests. In recent decades, salt marshes have suffered great degradation and loss all over the world. The idea to enhance carbon stock in salt marshes(so-called blue carbon) using biochar (so-called black carbon) has recently been proposed. Although experiments and observations remain limited, significant enhancements in soil organic carbon and plant growth have been documented in most case studies. However, due to the limited number of observations and their relatively short time window ranging from months to less than one year, there still exists a knowledge gap regarding the process, mechanism, and effect of biochar in enhancing carbon stock in salt marshes. Future research is urgently needed in the following perspectives:1) exploring the relationship between carbon stock enhancement efficiency and biochar properties, 2. optimizing the physical and chemical properties of biochar to boost its efficiency, and 3)studying the in-situ responses of complex carbon pools to biochar addition, especially under tidal conditions and over a longer period of time.

关键词： soil stock char

QUANTITATIVE SUBSIDENCE ANALYSIS OFTHE TENSIVE BASIN AND COMPRESSIVEMOUNTAIN TYPE DIWA BASIN WITH IMPLICATIONS FOR EPISODIC TECTONIC MOVEMENT AND SEDIMENTATION

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Geotectonica et Metallogenia 1999年第2期23卷 125-133页

作者： Yang Minghui and Wei Yongpei(department of geology,{2., xi’ an 710069, china )

This paper presents a quantitative analysis of Jurassic-Quaternary basement subsidence in the Delingha basin, a tensile basin and compressive mountain type diwa basin, and corrected for local sediment loading. Subsidence patterns have been investigated for the effects of erosion induced uplift by means of analytical estimation. The history of the Delingha basin has been divided into four stages: 2.4(?)~130 Ma (SⅠ ), 130~95 Ma (SⅡ ), 67~35 Ma (SⅢ ) and 35~0 Ma (SⅣ ), recording episodic tectonics and sedimentation respectively.

关键词： Tensive basin and compressive mountain diwa basin subsidence analysis depositional system the northern Qaidam basin

Essentially Commuting Truncated Toeplitz Operators

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Acta Mathematica Sinica,English Series 2024年第10期40卷 2453-2480页

作者： xi ZHAO Tao YU School of Mathematics and Science Hebei GEO University School of Mathematical Sciences Dalian University of Technology

A model space is a subspace of the Hardy space which is invariant under the backward shift,and a truncated Toeplitz operator is the compression of a Toeplitz operator on some model space. In this paper we prove a necessary and sufficient condition for the commutator of two truncated Toeplitz operators on a model space to be compact.

关键词： 47B32 47B35 commutator compact operator maximal ideal space model space Truncated Toeplitz operator

Cartesian closedness of categories of completely distributive lattices

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Chinese Science Bulletin 1998年第24期43卷 2059-2063页

作者： ZHANG Dexue 1 and YANG Zhongqiang 2.1. department of Mathematics, Sichuan university, Chengdu 610064,{2. 2. department of Mathematics, Shaanxi Normal university, xi’an 710062.{2. department of Mathematics Sichuan University Chengdu China department of Mathematics Shaanxi Normal University Xi’an China

The category of completely distributive lattices with Scott continuous functions is cartesian closed. Neither the category of completely distributive lattices with arbitrary union preserving mappings nor the category ... 详细信息

关键词： completely distributive lattice continuous lattice cartesian closedness.