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排序方式: 共有224条查询结果,搜索用时 237 毫秒
121.
In this paper we describe two limiting processes for families of Banach spaces closely related to the standard definition of projective and inductive limits. These processes lead again to Banach spaces. Information about linear operators and duality between basic families of spaces is carried over to the corresponding limit spaces. The abstract results are shown to be applicable to Campanato spaces and Sobolev-Campanato spaces. In particular, we obtain the existence and a characterization of predual spaces. Some imbedding relations are investigated in more detail. 相似文献
122.
Traditional 3D‐quantitative structure–activity relationship (QSAR)/structure–activity relationship (SAR) methodologies are sensitive to the quality of an alignment step which is required to make molecular structures comparable. Even though many methods have been proposed to solve this problem, they often result in a loss of model interpretability. The requirement of alignment is a restriction imposed by traditional regression methods due to their failure to represent relations between data objects directly. Inductive logic programming (ILP) is a class of machine‐learning methods able to describe relational data directly. We propose a new methodology which is aimed at using the richness in molecular interaction fields (MIFs) without being restricted by any alignment procedure. A set of MIFs is computed and further compressed by finding their minima corresponding to the sites of strongest interaction between a molecule and the applied test probe. ILP uses these minima to build easily interpretable rules about activity expressed as pharmacophore rules in the powerful language of first‐order logic. We use a set of previously published inhibitors of factor Xa of the benzamidine family to discuss the problems, requirements and advantages of the new methodology. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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The polymerization of vinyl chloride with Cp*TiX3/MAO (X = OCH3, OC4H9, OPh, Cl) catalysts in CH2Cl2 was investigated. The activity of the Cp*TiX3/MAO catalytic systems depends on ligand X in that increased activity was found for increasing electron‐donating capacity of X. The relationship between Hammet's σm of ligand X and polymer yield gave a straight line, indicating that the electronic effect of X plays an important role. 相似文献
125.
以串联型感应电能传输(IPT)系统为例,用非线性动力学的方法研究了IPT系统的多谐振点的判断及稳定性分析问题.建立了系统的频闪映射模型,根据不动点理论推导出了系统的稳态响应分段解析函数式,并在此基础上,给出了系统谐振工作点的理论判据,结合系统庞加莱映射的雅可比矩阵特征值分布情况,给出了谐振点的稳定性判据.结合具体实例系统,讨论了其多谐振点现象,并通过仿真和实验进行了验证,证明了本文理论分析结果的正确性.本文所提出的分析方法也可为其他类似谐振变换电路的建模及稳态工作点分析提供一定的理论参考.
关键词:
感应电能传输(IPT)
频闪映射
雅可比矩阵
稳定性 相似文献
126.
In the first part of this paper we discuss the completeness of two general classes of weighted inductive limits of spaces of ultradifferentiable functions. In the second part we study their duals and characterize these spaces in terms of the growth of convolution averages of their elements. This characterization gives a canonical way to define a locally convex topology on these spaces and we give necessary and sufficient conditions for them to be ultrabornological. In particular, our results apply to spaces of convolutors for Gelfand–Shilov spaces. 相似文献
127.
Degradation and breakdown behaviors of SGTs under repetitive unclamped inductive switching avalanche stress
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Chenkai Zhu 《中国物理 B》2022,31(9):97303-097303
The repetitive unclamped inductive switching (UIS) avalanche stress is conducted to investigate the degradation and breakdown behaviors of conventional shield gate trench MOSFET (C-SGT) and P-ring SGT MOSFETs (P-SGT). It is found that the static and dynamic parameters of both devices show different degrees of degradation. Combining experimental and simulation results, the hot holes trapped into the Si/SiO2 interface and the increase of crystal lattice temperature should be responsible for the degradation and breakdown behaviors. Moreover, under repetitive UIS avalanche stress, the reliability of P-SGT overcomes that of C-SGT, benefitting from the decreasing of the impact ionization rate at bottom of field oxide caused by the existence of P-ring. 相似文献
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Jinlu Li 《Optimization》2018,67(5):565-583
In this paper, we introduce the concept of isotone cones in Banach spaces. Then, we apply the order monotonic property of the metric projection operator to prove the existence of best approximations for some operators without continuity conditions in partially ordered Banach spaces. 相似文献