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排序方式: 共有748条查询结果,搜索用时 31 毫秒
722.
Cai Tie De‐Wen Zhang Hong‐Xu Chen Sen‐Lin Song Xin‐Xiang Zhang 《Journal of mass spectrometry : JMS》2012,47(11):1429-1434
With the combination of high separation ability of capillary electrophoresis (CE) and strong identification ability of mass spectrometry (MS), CE/MS is becoming a powerful tool for polar and ionic analytes analysis. Different interfaces have been developed to enhance the sensitivity and reliability since the first introduction of CE/MS in 1987. A sheathless porous interface based on a new ions transferring electric connection technique was reported to be with high sensitivity and reliability. In this work, a series of optical and electrochemical experiments were designed to study the electric connection process. The results indicated that closing CE electrical circuit and applying MS spray voltage were achieved by the small ions transferring through the interface porous wall. The new electric connection method significantly enhanced the sensitivity, resolution and stability of the CE/MS analysis. The interface was applied in CE/MS detection of morphine and 6‐monoacetylmorphine in urine sample and showed an equal sensitivity to LC/MS. With the significant improvement of sensitivity and stability, the CE/MS with the new interface showed strong potential for the determination of low abundance analytes. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
723.
For a finite simple edge-colored connected graph G (the coloring may not be proper), a rainbow path in G is a path without two edges colored the same; G is rainbow connected if for any two vertices of G, there is a rainbow path connecting them. Rainbow connection number, rc(G), of G is the minimum number of colors needed to color its edges such that G is rainbow connected. Chakraborty et al. (2011) [5] proved that computing rc(G) is NP-hard and deciding if rc(G)=2 is NP-complete. When edges of G are colored with fixed number k of colors, Kratochvil [6] proposed a question: what is the complexity of deciding whether G is rainbow connected? is this an FPT problem? In this paper, we prove that any maximal outerplanar graph is k rainbow connected for suitably large k and can be given a rainbow coloring in polynomial time. 相似文献
724.
Francesco M. Malvestuto 《Discrete Mathematics》2009,309(13):4287-234
Known properties of “canonical connections” from database theory and of “closed sets” from statistics implicitly define a hypergraph convexity, here called canonical convexity (c-convexity), and provide an efficient algorithm to compute c-convex hulls. We characterize the class of hypergraphs in which c-convexity enjoys the Minkowski-Krein-Milman property. Moreover, we compare c-convexity with the natural extension to hypergraphs of monophonic convexity (or m-convexity), and prove that: (1) m-convexity is coarser than c-convexity, (2) m-convexity and c-convexity are equivalent in conformal hypergraphs, and (3) m-convex hulls can be computed in the same efficient way as c-convex hulls. 相似文献
725.
The concept of fuzzy Galois connections is defined on fuzzy posets with Bělohlávek's fuzzy Galois connections as a special case. The properties of fuzzy Galois connections are investigated. Then the relations between fuzzy Galois connections and fuzzy closure operators, fuzzy interior operators are studied. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
726.
应用数学机械化方法研究欧氏空间中$SU(2)$ Yang-Mills规范场的存在性问题.首先对YM--方程的结构进行了讨论,说明YM--方程由它的奇部份和偶部份联立组成.对于YM--方程构造了一类线性微分变换,称之为$SU(2)$规范场的示性变换.经示性变换,将非线性的YM--方程的奇部份变为一组Laplace方程,实现了$SU(2)$规范场方程的线性化.从而证明了$SU(2)$规范场存在3个独立的Yang-Mills规范场. 相似文献
727.
任新安 《数学物理学报(B辑英文版)》2009,29(2):447-455
In [6], a global solution of Yang-Mills equation on de-Sitter spacetime with conformal fiat metric was given by Prof. Lu. In this article, Yang-Mills equation on ndimensional de-Sitter space with Beltrami-Hua-Lu metric is discussed and a global solution is obtained. 相似文献
728.
K¨ahler Finsler Metrics Are Actually Strongly K¨ahler 总被引:6,自引:1,他引:5
In this paper, the Kahler conditions of the Chern-Finsler connection in complex Finsler geometry are studied, and it is proved that Kahler Finsler metrics are actually strongly Kahler. 相似文献
729.
研究了属性权重范围已知,方案主观偏好值为语言变量,决策信息为不确定语言决策矩阵的多属性决策问题.在给出不确定语言变量转换为二元联系数的公式以及二元联系数距离公式的基础上,将方案主观偏好语言评价值转换为二元联系数,将不确定语言决策矩阵转换为二元联系数决策矩阵,从而得到方案的二元联系数综合属性值,通过最小化方案的二元联系数综合属性值和主观偏好值之间距离,建立多目标优化模型,并将其转换为一个单目标规划模型计算出属性权重.然后,通过对方案的二元联系数综合属性值进行不确定性分析,得到各方案的排序总数,利用排序总数对方案进行排序择优.应用实例表明该决策方法可行有效. 相似文献
730.
HSU Jong-Ping 《中国物理 C》2012,(5):403-409
Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T (4) × [SU (3)] color in flat space-time, we have a unified model of chromo-gravity with a new tensor gauge field, which couples universally to all gluons, quarks and anti-quarks. The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same ’effective Riemann metric tensors’ in the geometric-optics (or classical) limit. The emergence of ef f ective metric tensors in the classical limit is essential for the unified model to agree with experiments. The unified model suggests that all gravitational, strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework. 相似文献