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2,2-双[4-(3-氨基苯氧基)苯基]丙烷制备及其可溶性聚酰亚胺的研究 被引量:30
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作者 虞鑫海 胡志强 《绝缘材料》 CAS 北大核心 2001年第6期3-6,共4页
本文以 2 ,2 -双 [4- (3-硝基苯氧基 )苯基 ]丙烷 (3- BNPOPP)为原料 ,在活性炭 ,六水氯化铁 (Fe Cl3 · 6 H2 O)和水合肼 (H2 NNH2·H2 O)的共同作用下还原制得 2 ,2 -双 [4- (3-氨基苯氧基 )苯基 ]丙烷 (3- BNPOPP)。经熔点... 本文以 2 ,2 -双 [4- (3-硝基苯氧基 )苯基 ]丙烷 (3- BNPOPP)为原料 ,在活性炭 ,六水氯化铁 (Fe Cl3 · 6 H2 O)和水合肼 (H2 NNH2·H2 O)的共同作用下还原制得 2 ,2 -双 [4- (3-氨基苯氧基 )苯基 ]丙烷 (3- BNPOPP)。经熔点测试、红外光谱、核磁共振和元素分析等手段对其进行了表征。以 3- BNPOPP为单体 ,合成了可溶性好 。 展开更多
关键词 2 2-双[4-(3-氨基苯氧基)苯基]丙烷 合成 聚酰亚胺 可溶性 绝缘材料
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Uniform supersaturated design and its construction 被引量:8
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作者 方开泰 葛根年 刘民千 《Science China Mathematics》 SCIE 2002年第8期1080-1088,共9页
Supersaturated designs are factorial designs in which the number of main effects is greater than the number of experimental runs. In this paper, a discrete discrepancy is proposed as a measure of uniformity for supers... Supersaturated designs are factorial designs in which the number of main effects is greater than the number of experimental runs. In this paper, a discrete discrepancy is proposed as a measure of uniformity for supersaturated designs, and a lower bound of this discrepancy is obtained asa benchmark of design uniformity. A construction method for uniform supersaturated designs via resolvable balanced incomplete block designs is also presented along with the investigation of properties of the resulting designs. The construction method shows a strong link between these two different kinds of designs. 展开更多
关键词 discrepancy resolvable BALANCED INCOMPLETE block design supersaturated design uniformity.
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基于MRTD信道宽度的热成像系统性能评价理论研究 被引量:7
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作者 王吉晖 金伟其 +1 位作者 王霞 王岭雪 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2007年第4期256-260,共5页
热成像系统与人眼之间存在最佳匹配问题,存在一个最佳的角放大率使人眼与成像系统达到最佳的匹配状态,使系统性能达到最佳.本文提出一种基于信噪比模型的热成像系统性能评价方法,导出了一个基于MRTD信道宽度的热成像系统评价参量.通过... 热成像系统与人眼之间存在最佳匹配问题,存在一个最佳的角放大率使人眼与成像系统达到最佳的匹配状态,使系统性能达到最佳.本文提出一种基于信噪比模型的热成像系统性能评价方法,导出了一个基于MRTD信道宽度的热成像系统评价参量.通过对实际热成像系统的观察实验和分析比较,表明使用这个评价参量,可以获得热成像系统的最佳角放大率或最佳观察距离,使系统与人眼视觉得到最佳的匹配状态.结果对于进一步发展光电成像系统的性能评价理论具有理论意义,而且可望对实际系统的设计提供理论指导. 展开更多
关键词 热成像系统 最优化 最小可分辨温差MRTD(Minimum resolvable Temperature Difference) 角放大率 观察距离
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Tripling Construction for Large Sets of Resolvable Directed Triple Systems 被引量:3
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作者 Jun Ling ZHOU Yan Xun CHANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2006年第1期311-318,共8页
In this paper, we first define a doubly transitive resolvable idempotent quasigroup (DTRIQ), and show that aDTRIQ of order v exists if and only ifv ≡0(mod3) and v ≠ 2(mod4). Then we use DTRIQ to present a trip... In this paper, we first define a doubly transitive resolvable idempotent quasigroup (DTRIQ), and show that aDTRIQ of order v exists if and only ifv ≡0(mod3) and v ≠ 2(mod4). Then we use DTRIQ to present a tripling construction for large sets of resolvable directed triple systems, which improves an earlier version of tripling construction by Kang (J. Combin. Designs, 4 (1996), 301-321). As an application, we obtain an LRDTS(4·3^n) for any integer n ≥ 1, which provides an infinite family of even orders. 展开更多
关键词 Doubly transitive resolvable idempotent quasigroup resolvable directed triple system Large set Tripling construction
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More Large Sets of Resolvable MTS and DTS with Even Orders
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作者 Qing-de Kang Rong-jia Xu 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2008年第2期233-252,共20页
In this paper, we first introduce a special structure that allows us to construct a large set of resolvable Mendelsohn triple systems of orders 2q + 2, or LRMTS(2q + 2), where q = 6t + 5 is a prime power. Using a... In this paper, we first introduce a special structure that allows us to construct a large set of resolvable Mendelsohn triple systems of orders 2q + 2, or LRMTS(2q + 2), where q = 6t + 5 is a prime power. Using a computer, we find examples of such structure for t C T = {0, 1, 2, 3, 4, 6, 7, 8, 9, 14, 16, 18, 20, 22, 24}. Furthermore, by a method we introduced in [13], large set of resolvable directed triple systems with the same orders are obtained too. Finally, by the tripling construction and product construction for LRMTS and LRDTS introduced in [2, 20, 21], and by the new results for LR-design in [8], we obtain the existence for LRMTS(v)and LRDTS(v), where v = 12(t + 1) mi≥0(2.7mi+1)mi≥0(2.13ni+1)and t∈T,which provides more infinite family for LRMTS and LRDTS of even orders. 展开更多
关键词 Large set resolvable Mendelsohn triple system tripling construction resolvable directed triple system
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RESOLVABLE TWOFOLD TRIPLE SYSTEMS WITHOUT REPEATED TRIPLES
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作者 沈灏 《Chinese Science Bulletin》 SCIE EI CAS 1990年第2期89-92,共4页
Ⅰ. INTRODUCTIONA triple system S<sub>λ</sub>(2, 3, v)is an ordered pair (V,), where Vis a v-set, is a collection of 3-subsets (called triples ) of V such that each pair of distinct dements of V is ... Ⅰ. INTRODUCTIONA triple system S<sub>λ</sub>(2, 3, v)is an ordered pair (V,), where Vis a v-set, is a collection of 3-subsets (called triples ) of V such that each pair of distinct dements of V is contained in exactly λ triples. An S<sub>2</sub>(2, 3, v)is called a twofold triple system. 展开更多
关键词 twofold TRIPLE system resolvable ALMOST resolvable simple.
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A SURVEY OF ORTHOGONAL ARRAYS OF STRENGTH TWO 被引量:1
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作者 刘璋温 井淑夫 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1995年第3期308-317,共10页
The purpose of this paper is to survey the construction of orthogonal arrays of strength two by using difference sets. Some methods for constructing difference set D(2p.2p,p,2), where p is a prime or a prime power, ar... The purpose of this paper is to survey the construction of orthogonal arrays of strength two by using difference sets. Some methods for constructing difference set D(2p.2p,p,2), where p is a prime or a prime power, are given. It is shown that the Kronecker sum of a difference set D(λ1p, k1, p, 2) and an orthogonal array(λ2p2, k2, p, 2) leads to another orthogonal array (λ1λ2p3 .k1k2+1 ,p, 2). This enables us to construct orthogonal arrays[2p(n+1)、1+2(p+p2 +…+pn),p,2],[4p(n+2),1+2p+4(p2+p3+…+p(n+1)),p, 2],and [8p(n+3),1+2P+4p2+8(p3+p4+…+p(n+2)),p,2]where p is a prime or a prime power. 展开更多
关键词 Orthogonal array difference set kronecker sum affine resolvable BIB design
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双循环Kirkman三元系的存在性 被引量:3
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作者 顾宗敏 沈灏 《上海交通大学学报》 EI CAS CSCD 北大核心 2005年第10期1722-1726,共5页
研究了双循环K irkm an三元系的存在性.证明了当<υ300时,除去υ=207、243和261这3个可能的例外,双循环KTS(υ)存在的充分必要条件是:υ≡3(m od 6)且v/3不是形如q≡5(m od 6)的素数.
关键词 Steiner三元系 双循环 可分解 KIRKMAN 三元系
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U-Type Designs via New Generalized Partially Balanced Incomplete Block Designs with <i>m</i>= 4, 5 and 7 Associated Classes
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作者 Imane Rezgui Zebida Gheribi-Aoulmi Hervé Monod 《Applied Mathematics》 2015年第2期242-264,共23页
The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical ind... The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design). 展开更多
关键词 Association Scheme Combinatory Method (s) resolvable PARTIALLY Balanced Incomplete Block DESIGN U-Type DESIGN
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Almost resolvable maximum packings of complete graphs with 5-cycles
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作者 Min ZHOU Haitao CAO 《Frontiers of Mathematics in China》 SCIE CSCD 2015年第2期461-475,共15页
Let X be the vertex set of Kn. A k-cycle packing of Kn is a triple (X, C, L), where C is a collection of edge disjoint k-cycles of Kn and L is the collection of edges of Kn not belonging to any of the k-cycles in C.... Let X be the vertex set of Kn. A k-cycle packing of Kn is a triple (X, C, L), where C is a collection of edge disjoint k-cycles of Kn and L is the collection of edges of Kn not belonging to any of the k-cycles in C. A k-cycle packing (X, C, L) is called resolvable if C can be partitioned into almost parallel classes. A resolvable maximum k-cycle packing of Kn, denoted by k-RMCP(n), is a resolvable k-cycle packing of Kn, (X, C, L), in which the number of almost parallel classes is as large as possible. Let D(n, k) denote the number of almost parallel classes in a k-RMCP(n). D(n, k) for k = 3, 4 has been decided. When n ≡ k (mod 2k) and k ≡1 (mod 2) or n ≡1 (mod 2k) and k e {6, 8, 10, 14} U{m: 5 ≤ m ≤ 49, m ≡1 (mod 2)}, D(n,k) also has been decided with few possible exceptions. In this paper, we shall decide D(n, 5) for all values of n ≥ 5. 展开更多
关键词 Cycle packing resolvable maximum cycle packing cycle frame
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Near generalized balanced tournament designs with block sizes 4 and 5
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作者 SHAN XiuLing1, 2 1 Department of Mathematics, Beijing Jiaotong University, Beijing 100044, China 2 College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050016, China 《Science China Mathematics》 SCIE 2009年第9期1927-1938,共12页
A near generalized balanced tournament design, or an NGBTD(k,m) in short, is a (km+1,k,k-1)-BIBD defined on a (km+1)-set V . Its blocks can be arranged into an m×(km+1) array in such a way that (1) the blocks in ... A near generalized balanced tournament design, or an NGBTD(k,m) in short, is a (km+1,k,k-1)-BIBD defined on a (km+1)-set V . Its blocks can be arranged into an m×(km+1) array in such a way that (1) the blocks in every column of the array form a partial parallel class partitioning V\{x} for some point x, and (2) every element of V is contained in precise k cells of each row. In this paper, we completely solve the existence of NGBTD(4,m) and almost completely solve the existence of NGBTD(5,m) with four exceptions. 展开更多
关键词 near generalized balanced tournament designs frame generalized doubly resolvable packing constructions existence 05B05
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FURTHER RESULTS ON THE EXISTENCE OF LABELED RESOLVABLE BLOCK DESIGNS
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作者 沈灏 沈佳颖 《Journal of Shanghai Jiaotong university(Science)》 EI 1999年第2期52-56,共5页
It was proved in this paper that there exists a labeled resolvable block design LRB (4,3; v ) if and only if v ≡0 (mod 4) and v ≥8, with 8 possible exceptions. It was also proved that there exists a nearly Kirkman s... It was proved in this paper that there exists a labeled resolvable block design LRB (4,3; v ) if and only if v ≡0 (mod 4) and v ≥8, with 8 possible exceptions. It was also proved that there exists a nearly Kirkman system NKS (2,4; v ) if and only if v ≡0 (mod 12) and v ≥24, except possibly when v =264 or 372. 展开更多
关键词 labeled resolvable BLOCK DESIGN NEARLY KIRKMAN system group divisible DESIGN
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Resolvable Spaces and Compactifications
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作者 Monerah Al-Hajri Karim Belaid 《Advances in Pure Mathematics》 2013年第3期365-367,共3页
This paper deals with spaces such that their compactification is a resolvable space. A characterization of space such that its one point compactification (resp. Wallman compactification) is a resolvable space is given.
关键词 resolvable SPACE Alexandroff COMPACTIFICATION Wallman COMPACTIFICATION
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A GLOBAL SPECTRAL MODEL WITH VARIABLE POLES AND ITS APPLICATION TO THE SHALLOW-WATER EQUATIONS
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作者 赵其庚 《Acta meteorologica Sinica》 SCIE 1991年第2期204-214,共11页
Since we find out that the global spectral model with trapezoidal truncation has higher resolution in high latitudes(polar cap)than in low latitudes,this paper presents a global spectral model with variable poles whic... Since we find out that the global spectral model with trapezoidal truncation has higher resolution in high latitudes(polar cap)than in low latitudes,this paper presents a global spectral model with variable poles which can be located at the center of interested area.The transform methods from traditional global spectral model to the new model are given and applied to a shallow-water equation model.The control ex- periments for 72h predictions were carried out.The“northern pole”in the transformed model was located at 15°N,135°E.And the results showed that the predictions of weather systems in the area around the“new pole”(the polar cap,latitudes >60°)were better than those by the traditional model and the root mean square errors were improved. 展开更多
关键词 traditional spectral model variable pole trapezoidal truncation resolvable half wavelength
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Reasoning with Inconsistent Ontologies
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作者 方俊 Zhisheng Huang 《Tsinghua Science and Technology》 SCIE EI CAS 2010年第6期687-691,共5页
Reasoning with inconsistent ontologies involves using an inconsistency reasoner to get meaningful answers from inconsistent ontologies. This paper introduces an improved inconsistency reasoner, which selects consisten... Reasoning with inconsistent ontologies involves using an inconsistency reasoner to get meaningful answers from inconsistent ontologies. This paper introduces an improved inconsistency reasoner, which selects consistent subsets using minimal inconsistent sets and a resolution method, to improve the run-time performance of the reasoning processing. A minimal inconsistent set contains a minimal explanation for the inconsistency of a given ontology. Thus, it can replace the consistency checking operation, which is executed frequently in existing approaches. When selecting subsets of the inconsistent ontology, formulas which can be directly or indirectly resolved with the negation of the query formula are selected because only those formulas affect the consequences of the reasoner. Therefore, the complexity of the reasoning processing is significantly reduced. Tests show that the run-time performance of the inconsistency reasoner is significantly improved. 展开更多
关键词 minimal inconsistent set (MIS) inconsistency reasoner resolvable relevance inconsistent ontologies
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带可分解性质的幂等拟群大集
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作者 周君灵 常彦勋 《中国科学:数学》 CSCD 北大核心 2012年第10期1037-1045,共9页
具有幂单正交侣的幂等拟群称为可分解的.具有幂等正交侣的幂等拟群称为几乎可分解的.若v元集合上的所有分量互不相同的3-向量能够分拆成互不相交(幂等3-向量除外)的v2个v阶幂等拟群,则称之为v阶幂等拟群大集.本文使用t-平衡设计(t=2,3)... 具有幂单正交侣的幂等拟群称为可分解的.具有幂等正交侣的幂等拟群称为几乎可分解的.若v元集合上的所有分量互不相同的3-向量能够分拆成互不相交(幂等3-向量除外)的v2个v阶幂等拟群,则称之为v阶幂等拟群大集.本文使用t-平衡设计(t=2,3)的方法给出了可分解幂等拟群大集、几乎可分解幂等拟群大集及可分解对称幂等拟群大集(即可分解高尔夫设计)的构造方法,给出了其存在性的若干结果. 展开更多
关键词 幂等拟群 对称 有序设计 可分解 几乎可分解 大集
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THE EXISTENCE OF RESOLVABLE BIBD WITH λ = 1
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作者 常彦勋 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2000年第4期373-385,共13页
Let k be any integer and k≥3. In this article it is proved that the necessary condition υ=k (mod k(k-1)) for the existence of an RB(v,k,1) is sufficient whenever u>exp{exp{k12k2}}.
关键词 Pairwise balanced design PBD-closed resolvable BIBD
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α-Resolvable Cycle Systems for Cycle Length 4 被引量:1
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作者 马秀文 田子红 《Journal of Mathematical Research and Exposition》 CSCD 2009年第6期1102-1106,共5页
An m-cycle system of order v and index λ, denoted by m-CS(v,λ), is a collection of cycles of length m whose edges partition the edges of λKv. An m-CS(v,λ) is α-resolvable if its cycles can be partitioned into cla... An m-cycle system of order v and index λ, denoted by m-CS(v,λ), is a collection of cycles of length m whose edges partition the edges of λKv. An m-CS(v,λ) is α-resolvable if its cycles can be partitioned into classes such that each point of the design occurs in precisely α cycles in each class. The necessary conditions for the existence of such a design are m|λv(v-1)/2,2|λ(v -1),m|αv,α|λ(v-1)/2. It is shown in this paper that these conditions are also sufficient when m = 4. 展开更多
关键词 CYCLE cycle system a-resolvable.
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可分解时域信号的采样分析
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作者 冯锦 任长学 《通信学报》 EI CSCD 北大核心 2002年第8期45-51,共7页
模拟信号的数字化一直是信号处理中的基本问题,在这些信号中有一类信号可以分解为一些已知信号的线性和。本文从纯时域角度出发,以线性代数作为工具给出了这类信号的分析理论及相应的推论,同时利用这些结论对典型的带限信号进行了分析... 模拟信号的数字化一直是信号处理中的基本问题,在这些信号中有一类信号可以分解为一些已知信号的线性和。本文从纯时域角度出发,以线性代数作为工具给出了这类信号的分析理论及相应的推论,同时利用这些结论对典型的带限信号进行了分析并初步探讨了这类信号的采样与恢复的实现问题。 展开更多
关键词 可分解 时域信号 采样 线性 基波 信号分析
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(D_(3)(4),λ)-支架和(D_(3)(4),λ)-可分解的可分组设计的存在谱
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作者 杨青 郑义 《淮阴师范学院学报(自然科学版)》 CAS 2022年第1期7-10,16,共5页
利用一些已知结果和递归构造法,证明了型为g^(u)的(D_(3)(4),λ)-支架和(D_(3)(4),λ)-可分解的可分组设计存在的必要条件也是充分的.对任意相遇数λ,解决了这两类设计的存在性.
关键词 G-分解 支架 可分解 可分组设计
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