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一个新的单调类定理   总被引:5,自引:0,他引:5  
定义了集类的w类的概念,给出了w类的单调类定理.  相似文献   

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A merozoite vaccine effective against Plasmodium knowlesi malaria   总被引:7,自引:0,他引:7  
G H Mitchell  G A Butcher  S Cohen 《Nature》1974,252(5481):311-313
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研究每个处理挂在两条总线上的多总线结构的容错设计问题,提出了一类新的具有较佳(最佳)容错性和可扩充性的多总线结构.  相似文献   

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Abstract Applying an analysis method to a group of multivariable equations, a new class of variational equations are proved. Thismethod is more concise and more direct than the others. This result can be applied to some stochastic control models.  相似文献   

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A labeling/of a graph G is a bijection from its edge set E(G) to the set {1,2,…,|E(G)|},which is antimagic if for any distinct vertices x anAy,the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y.A graph G is antimagic if G has an f which is antimagic.Hartsfield and Ringel conjectured in 1990 that every connected graph other than K_2 is antimagic.In this paper,we show that if G_1 is an m-vertex graph with maximum degree at most 6r+l,and G_2 is an n-vertex(2r)-regular graph(m≥n≥3),then the join graph G_1 v G_2 is antimagic.  相似文献   

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A new class of GABA agonist.   总被引:33,自引:0,他引:33  
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A new class of angiotensin-converting enzyme inhibitors   总被引:22,自引:0,他引:22  
Much current attention focuses on the renin-angiotensin system in relation to mechanisms controlling blood pressure and renal function. Recent demonstrations (ref. 1, ref. 2 and refs therein) that angiotensin-converting enzyme inhibitors show promising clinical antihypertensive properties have been of particular interest. We now report on the design of a novel series of substituted N-carboxymethyl-dipeptides which are active in inhibiting angiotensin-converting enzyme at nanomolar levels. We suggest that these compounds are transition-state inhibitors and that extensions of this design to other metalloendopeptidases merit further study.  相似文献   

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提出了一类新的求解无约束优化问题的记忆梯度法,在较弱条件下证明了该方法的全局收敛性和线性收敛速率.该算法无需任何线搜索而具有充分下降性,且搜索方向自适应在一个信赖域范围之内;该方法继承了著名PRP方法的一个主要性质:当步长很小时,搜索方向靠近于最速下降方向,避免了连续小步长的产生.初步的数值实验结果表明该方法是有效的.  相似文献   

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根据Klaus Dohmen等提出的图的新双变量色多项式概念,探究了一般图关于此定义的减边公式,利用它反复迭代后可以方便地求得任何图的新双变量色多项式,还利用它深入探讨了一些特殊图的新双变量色多项式公式.同时还探究了运用包含等偏序关系,利用M(o)bius反演法和“格子剖分”法求得图的新双变量色多项式.最后探讨了共点图的新双变量色多项式公式以及图的顶点和边与色多项式的关系.  相似文献   

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研究了位于由两对双曲柱面构成的波导管电磁场里的单电子的性质,得到了单电子在场中狄拉克方程的新一类精确解;计算了极化算符的本征函数。结果表明,自旋系数可用恒定极化算符的本征值确定。这种方法可描述任意类型波导管里的电流磁化。  相似文献   

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A trusted third party introduced in watermarking protocols would decrease the security and affect the implementation of the protocols. In this paper, a new watermarking protocol with an un-trusted third party (UTTP) was proposed. Based on the idea of all-or-nothing disclosure of secret (ANDOS), all of the buyer, the seller and the third party didn't know the exact watermark, which was embedded in a digital content for tracing piracy. The proposed protocol provided mechanisms to trace piracy and protect customer's right. In addition, the problem that a seller colluded with UTTP to frame the buyer, namely, the conspiracy problem, could be avoided.  相似文献   

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图G的CB一划分是指:G的一个顶点划分{V1,V2,…,Vn},使得每个G[Vi]为多重完全二部图(1≤i≤n).结合图的顶点CB-划分条件,确定了一类顶点的度在moalulo 4下值为0,1或3的上可嵌入图类,较完整地刻画了这类图的上可嵌入情况.  相似文献   

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Quorum sensing is a term used to describe cell-to-cell communication that allows cell-density-dependent gene expression. Many bacteria use acyl-homoserine lactone (acyl-HSL) synthases to generate fatty acyl-HSL quorum-sensing signals, which function with signal receptors to control expression of specific genes. The fatty acyl group is derived from fatty acid biosynthesis and provides signal specificity, but the variety of signals is limited. Here we show that the photosynthetic bacterium Rhodopseudomonas palustris uses an acyl-HSL synthase to produce p-coumaroyl-HSL by using environmental p-coumaric acid rather than fatty acids from cellular pools. The bacterium has a signal receptor with homology to fatty acyl-HSL receptors that responds to p-coumaroyl-HSL to regulate global gene expression. We also found that p-coumaroyl-HSL is made by other bacteria including Bradyrhizobium sp. and Silicibacter pomeroyi. This discovery extends the range of possibilities for acyl-HSL quorum sensing and raises fundamental questions about quorum sensing within the context of environmental signalling.  相似文献   

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通过定义一类新的Salagean-type调和单叶函数,得到了该函数类的一个充分条件和偏差定理.  相似文献   

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Lavoie H  Therrien M 《Nature》2011,480(7377):329-330
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一种新的高效大型音乐数据库查询算法   总被引:5,自引:0,他引:5  
在基于哼唱的音乐信息检索领域中,查询处理算法一直是一个重要的研究课题。根据人对乐曲相似理解的实验结果,设计了新的基于单侧连续匹配的可容错的近似匹配的算法.此算法采用n—gram的顺序hash索引,加快了可容错的查询处理速度.还设计了一系列包括各种类型和各种数量错误的查询的实验,来比较该算法和其他两种常用算法的查询处理速度和容错能力.当测试数据集为78000首网上收集的MIDI乐曲段,包含各种错误的查询为1000个时,该算法取得79%的前3位命中率和87%的前10位命中率.这些结果表明,该方法的性能高于现有的算法.表2,参8。  相似文献   

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从Bernstein多项式和参数有理变换出发,构造了一类新型的有理调配函数—有理Bernstein函数类,讨论了它的分析性质;运用该函数类给出了一类有理Bezier曲线的生成方法,研究了一类有理Bezier曲线的几何性质和几种实用的有理Bezier曲线并给出了数值例子。  相似文献   

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