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CATALYTIC DEBROMINATION OF DIPHENYL BROMOMETHANE UNDER HETEROPHASE CONDITIONS USING POLYMERS WITH VIOLOGEN STRUCTURE
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作者 Fu Tian LIU Xian Da Yu Shu Ben LI Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou730000 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第7期577-580,共4页
The debromination of diphenyl bromomethane (Ph_2CHBr) using polymers with viologen structure as electron--transfer catalyst (ETC) afforded tetraphenylethane in good yields under het- erophase conditions.
关键词 PVA than CATALYTIC DEBROMINATION OF DIPHENYL BROMOMETHANE UNDER HETEROPHASE conditions USING POLYMERS WITH VIOLOGEN STRUCTURE
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Entropy Formulation for Triply Nonlinear Degenerate Elliptic-Parabolic-Hyperbolic Equation with Zero-Flux Boundary Condition
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作者 Mohamed Karimou Gazibo 《Journal of Applied Mathematics and Physics》 2023年第4期933-948,共16页
In this note, we investigated existence and uniqueness of entropy solution for triply nonlinear degenerate parabolic problem with zero-flux boundary condition. Accordingly to the case of doubly nonlinear degenerate pa... In this note, we investigated existence and uniqueness of entropy solution for triply nonlinear degenerate parabolic problem with zero-flux boundary condition. Accordingly to the case of doubly nonlinear degenerate parabolic hyperbolic equation, we propose a generalization of entropy formulation and prove existence and uniqueness result without any structure condition. 展开更多
关键词 Degenerate Elliptic-Parabolic Hyerbolic Equation Zero-Flux Boundary Condition Structure Condition Entropy Formulation Multi-Step Approximation Nonlinear Semigroup Theories Integral and Mild Solution
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Structured condition numbers and statistical condition estimation for the LDU factorization 被引量:1
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作者 Mahvish Samar Aamir Farooq MU Chun-lai 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2020年第3期332-348,共17页
In this article, we consider the structured condition numbers for LDU, factorization by using the modified matrix-vector approach and the differential calculus, which can be represented by sets of parameters. By setti... In this article, we consider the structured condition numbers for LDU, factorization by using the modified matrix-vector approach and the differential calculus, which can be represented by sets of parameters. By setting the specific norms and weight parameters, we present the expressions of the structured normwise, mixed, componentwise condition numbers and the corresponding results for unstructured ones. In addition, we investigate the statistical estimation of condition numbers of LDU factorization using the probabilistic spectral norm estimator and the small-sample statistical condition estimation method, and devise three algorithms. Finally, we compare the structured condition numbers with the corresponding unstructured ones in numerical experiments. 展开更多
关键词 LDU factorization Structured condition number Normwise condition number Mixed condition number Componentwise condition number
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Fluorescence Properties and Crystal Structures of Metal-organic Coordination Complexes Based on the 2,6-Naphthalenedicarboxylic Acid 被引量:1
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作者 胡兵相 周磊 +1 位作者 周泽宇 汪芳明 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第6期971-976,共6页
Two metal-organic coordination complexes, [Zn(2,6-ndc)(1,2-bix)]n(1) and [Zn(2,6-ndc)(1,3-bix)]n(2)(2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene and 1,3-... Two metal-organic coordination complexes, [Zn(2,6-ndc)(1,2-bix)]n(1) and [Zn(2,6-ndc)(1,3-bix)]n(2)(2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene and 1,3-bix = 1,3-bis(imidazole-1-ylmethyl)-benzene) have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions(π-π packing interactions) only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365(λ(ex) = 329 nm) and 367 nm(λex = 344 nm), respectively. 展开更多
关键词 fluorescence properties hydrothermal condition crystal structure
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THE EFFECT OF THE NEGATIVE ENTROPY FLOW ON THE ORGANIZATION OF ATMOSPHERIC DISSIPATIVE STRUCTURES IN NON-EQUILIBRIUM CONDITIONS
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作者 柳崇健 《Acta meteorologica Sinica》 SCIE 1989年第1期76-82,共7页
The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calc... The entropy balance equation that describes the entropy budget of atmospheric systems is derived from the Gibbs relation.The distribution of the entropy flows of a west-Pacific typhoon and a Bengal-Bay cyclone is calculated and thus the dissipativity of the atmospheric systems is revealed. 展开更多
关键词 THE EFFECT OF THE NEGATIVE ENTROPY FLOW ON THE ORGANIZATION OF ATMOSPHERIC DISSIPATIVE STRUCTURES IN NON-EQUILIBRIUM conditions Bay CSI GMT
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Structure condition under initial enlargement of filtration 被引量:1
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作者 CHOULLI Tahir DENG Jun 《Science China Mathematics》 SCIE CSCD 2017年第2期301-316,共16页
We address the question of how the structure condition is affected when one possesses some additional information at the very beginning of the investment period.The structure condition represents essentially an altern... We address the question of how the structure condition is affected when one possesses some additional information at the very beginning of the investment period.The structure condition represents essentially an alternative to non-arbitrage conditions for the Markowitz’s portfolio optimization framework,and is crucial for the existence of the optimal portfolio in quadratic utility settings.Herein,we provide practical assumption on the initial market model and the additional information to preserve the structure condition.The stochastic tools that drive this result are a generalization of the Lazaro-Yor representation by Lazaro and Yor(1978)and optional stochastic integral. 展开更多
关键词 structure condition initial enlargement of filtration optional stochastic integral
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Towards Fast and Efficient Algorithm for Learning Bayesian Network 被引量:2
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作者 LI Yanying YANG Youlong +1 位作者 ZHU Xiaofeng YANG Wenming 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2015年第3期214-220,共7页
Learning Bayesian network structure is one of the most exciting challenges in machine learning. Discovering a correct skeleton of a directed acyclic graph(DAG) is the foundation for dependency analysis algorithms fo... Learning Bayesian network structure is one of the most exciting challenges in machine learning. Discovering a correct skeleton of a directed acyclic graph(DAG) is the foundation for dependency analysis algorithms for this problem. Considering the unreliability of high order condition independence(CI) tests, and to improve the efficiency of a dependency analysis algorithm, the key steps are to use few numbers of CI tests and reduce the sizes of conditioning sets as much as possible. Based on these reasons and inspired by the algorithm PC, we present an algorithm, named fast and efficient PC(FEPC), for learning the adjacent neighbourhood of every variable. FEPC implements the CI tests by three kinds of orders, which reduces the high order CI tests significantly. Compared with current algorithm proposals, the experiment results show that FEPC has better accuracy with fewer numbers of condition independence tests and smaller size of conditioning sets. The highest reduction percentage of CI test is 83.3% by EFPC compared with PC algorithm. 展开更多
关键词 Bayesian network learning structure conditional independent test
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Application of Moore-Penrose Inverse in Deciding the Minimal Martingale Measure
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作者 Luo-gen Yao Gang Yang Xiang-qun Yang 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2010年第4期653-660,共8页
The Moore-Penrose inverse is an important tool in algebra.This paper shows that the MoorePenrose inverse is also an effcient technique in determining the minimal martingale measure if a security price follows a semi-m... The Moore-Penrose inverse is an important tool in algebra.This paper shows that the MoorePenrose inverse is also an effcient technique in determining the minimal martingale measure if a security price follows a semi-martingale which satisfies some structure condition.We extend a result of Dzhaparidze and Spreij concerning the Moore-Penrose inverse to the case that the Moore-Penrose inverse of any matrix-valued predictable process is still predictable.Furthermore,we obtain an explicit formula of the minimal martingale measure by employing the Moore-Penrose inverse.Specifically,the minimal martingale measure in a generalized Black-Scholes model is found. 展开更多
关键词 Moore-Penrose inverse minimal martingale measure semi-martingales structure condition
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STRUCTURED CONDITION NUMBERS FOR THE TIKHONOV REGULARIZATION OF DISCRETE ILL-POSED PROBLEMS
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作者 LingshengMeng Bing Zheng 《Journal of Computational Mathematics》 SCIE CSCD 2017年第2期169-186,共18页
The possibly most popular regularization method for solving the least squares problem rain ‖Ax - b‖2 with a highly ill-conditioned or rank deficient coefficient matrix A is the x Tikhonov regularization method. In ... The possibly most popular regularization method for solving the least squares problem rain ‖Ax - b‖2 with a highly ill-conditioned or rank deficient coefficient matrix A is the x Tikhonov regularization method. In this paper we present the explicit expressions of the normwise, mixed and componentwise condition numbers for the Tikhonov regularization when A has linear structures. The structured condition numbers in the special cases of nonlinear structure i.e. Vandermonde and Cauchy matrices are also considered. Some comparisons between structured condition numbers and unstructured condition numbers are made by numerical experiments. In addition, we also derive the normwise, mixed and componentwise condition numbers for the Tikhonov regularization when the coefficient matrix, regularization matrix and right-hand side vector are all perturbed, which generalize the results obtained by Chu et al. [Numer. Linear Algebra Appl., 18 (2011), 87-103]. 展开更多
关键词 Tikhonov regularization Discrete ill-posed problem Structured least squaresproblem Structured condition number.
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Markov branching processes with immigration-migration and resurrection 被引量:6
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作者 LI JunPing LIU ZaiMing 《Science China Mathematics》 SCIE 2011年第5期1043-1062,共20页
We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in deta... We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in detail. The explicit expressions for the extinction probabilities and mean extinction times are presented. The ergodicity and stability properties of the process incorporating with resurrection structure are then investigated. The conditions for recurrence, ergodicity and exponential ergodicity are obtained. An explicit expression for the equilibrium distribution is also presented. As a preparation, the criteria for regularity and uniqueness for such structure are firstly established. 展开更多
关键词 Markov branching process immigration migration resurrection regularity extinction recurrence ergodicity收藏本站首页期刊全文库学位论文库会议论文库吾喜杂志注册|登录|我的账户基础科学|工程科技I辑|工程科技II辑|医药卫生科技|信息科技|农业科技|哲学与人文科学|社会科学I辑|社会科学II辑|经济管理高级搜索: 用" Markov branching process immigration "到知网平台检索 点击这里搜索更多...《Science China(Mathematics)》 2011年05期 加入收藏 获取最新 Markov branching processes with immigration-migration and resurrection【摘要】: We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in detail. The explicit expressions for the extinction probabilities and mean extinction times are presented. The ergodicity and stability properties of the process incorporating with resurrection structure are then investigated. The conditions for recurrence ergodicity and exponential ergodicity are obtained. An explicit expression for the equilibrium distribution is also presented. As a preparation the criteria for regularity and uniqueness for such structure are firstly established.【关键词】 Markov branching process IMMIGRATION MIGRATION RESURRECTION REGULARITY EXTINCTION recur- rence ergodicity Keywords Markov branching process immigration migration resurrection regularity extinction recur-rence ergodicity
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