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半Σ准投射模自同态环的幂替换性质
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作者 魏加群 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2003年第1期41-44,共4页
证明了若半Σ准投射模分别是弱幂满投射的和弱幂同构投射的,则其自同态环分别具有弱右幂替换性质和幂替换性质,从而部分推广了WuTongsuo的一个主要结果.
关键词 自同态环 半∑准投射模 替换性质 弱幂满投射 弱幂同构投射
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完备同余关系的一个等价定义
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作者 张玉琦 《内蒙古师范大学学报(自然科学汉文版)》 CAS 1999年第4期272-276,共5页
定义了链传递关系,并且得出如下结果:(1) 设L 是完备格,θ是L上的完备同余关系θ是链传递的同余关系;(2) 设θ是L 上链传递关系,则θ是完备同余关系当且仅当θ满足替换性质(the Substitution Prope... 定义了链传递关系,并且得出如下结果:(1) 设L 是完备格,θ是L上的完备同余关系θ是链传递的同余关系;(2) 设θ是L 上链传递关系,则θ是完备同余关系当且仅当θ满足替换性质(the Substitution Property) . 展开更多
关键词 完备同余关系 链传递关系 替换性质 完备格
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The Logical Properties of Filters of Lattice Implication Algebra 被引量:3
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作者 王伟 徐扬 宋振明 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第3期8-13,共6页
In this paper, we discuss some propertie s of lattice implication algebra and difine the transitivity of implication in a set, we show the transitivity of implication and the substitution Theorem hold i n filters. S... In this paper, we discuss some propertie s of lattice implication algebra and difine the transitivity of implication in a set, we show the transitivity of implication and the substitution Theorem hold i n filters. So every filter of lattice implication algebra satisfies the Syllogis m and substitution Theorem of propositional logic. 展开更多
关键词 lattice implication algebra FILTER TRANSITIVITY
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First-principles calculation of electronic properties of N-and X(X=S,Se,Te)-codoped anatase TiO_2
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作者 李昌盛 任君 +3 位作者 郭海燕 彭兴 王建龙 曹端林 《Journal of Measurement Science and Instrumentation》 CAS 2014年第1期88-95,共8页
The impact of N-and X(X=S,Se,Te)-codoping on electronic properties of anatase TiO2 has been systematically investigated using density functional theory (DFT).The optimized geometry shows that there is large lattic... The impact of N-and X(X=S,Se,Te)-codoping on electronic properties of anatase TiO2 has been systematically investigated using density functional theory (DFT).The optimized geometry shows that there is large lattice expansion for the codoped anatase TiO2 due to large atomic radius of the codoped atom.The calculated substitution energies indicate that incorporation of X(X =S,Se,Te) into N-doped bulk TiO2 can not promote synergistic effect on N after substituting for Ti,whcreas it is bctter after substituting for O.According to the total density of states (DOS) and corresponding partial DOS (PDOS),it can be seen that substituting X(X =S,Se,Te) for O,N 2p orbital is strongly hybridized with impurity states (S 3p,Se 4p,Te 5p).After substituting X(X=S,Se,Te) for Ti,conduction band is mainly dominated by Ti 3d orbit and S 3p (Se 4p or Te 5p)-N 2p-Ti 3d hybridized states are formed.Based on Bader analysis,it can be indicated that the electron transfer is from N to X(X=S,Se,Te) if substituting X(X=S,Se,Te) for O,but it is opposite if substitute X(X=S,Se,Te) for Ti. 展开更多
关键词 anatase TiO2 electronic properties substitution energy CODOPING
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Investigation on Mechanical Properties of CMSLDS/Acrylate Copolymeric Blending Films for Warp Sizing
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作者 乔志勇 祝志峰 张斌 《Journal of Donghua University(English Edition)》 EI CAS 2010年第1期36-40,共5页
Carboxymethyl starch with lower degree of substitution was, blended with acrylate copolymer for revealing the relation between mechanical properties and chemical structure of blending film. Effects of carboxymethy... Carboxymethyl starch with lower degree of substitution was, blended with acrylate copolymer for revealing the relation between mechanical properties and chemical structure of blending film. Effects of carboxymethylation of starch, acrylate constituent units of acrylate copolymers, and copolymer content of the film on the properties were investigated. The mechanical properties were evaluated in terms of tensile strength, breaking elongation, abrasion resistance, and flex-fatigue resistance. Film morphology was examined with X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscope (AFM). It was found that the properties depended on the degree of substitution of carboxymethyl starch, chemical structure of acrylate units, and content of acrylate copolymer. Phase-separation of the two ingredients occurred within film matrix and the separation was decreased after starch carboxymethylation. Breaking elongation and flex-fatigue resistance of the film reached maximmns when acrylate copolymer content was 50%. Excessively increasing the content of acrylate copolymer reduced the film properties. 展开更多
关键词 carboxymethyl starch acrylate copolymer blending film mechanical properties degree of substitution
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Rough Set中正区域的若干性质 被引量:4
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作者 叶东毅 陈昭炯 《福州大学学报(自然科学版)》 CAS CSCD 2002年第5期521-523,共3页
分析了不同正区域之间的关系 ,在此基础上给出有关正区域计算的若干新的性质 ,如记录过滤性质、替换计算性质和分解计算性质等 .利用这些性质可以降低正区域动态计算的计算量 .
关键词 ROUGH SET 粗糙集理论 正区域 记录过滤性质 替换计算性质 分解计算性质 计算量
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正交模格上关于同余关系的格等式的证明
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作者 韩荣梅 《阴山学刊(自然科学版)》 2016年第2期5-6,共2页
介绍了正交模格上关于同余关系的格等式。通过证明格等式可知,在正交模格上的一个自反的对称的二元运算θ是同余关系,当且仅当θ对交并运算具有替换性质,并且在正交模格上的一种同余关系是由它的核所决定的。
关键词 正交模格 同余关系 替换性质
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