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排序方式: 共有491条查询结果,搜索用时 15 毫秒
21.
A novel silane coupling agent bearing sulfobetaine group, N,N-diethyl-N-(3-sulfopropyl)-aminopropyl- trimethoxysilane (DESATS), was first designed, synthesized and characterized. Its solution property was studied by means of dynamic light scattering. DESATS was successfully bonded onto the surface of the glass and proved by ESCA. Platelet adhesion assay in vitro indicated that the nonthrombogenicity of glass slide modified with DESATS is greatly improved. 相似文献
22.
23.
Considering a single-mode laser system with cross-correlated additive colored noise and multiplicative colored noise, we study the effects of correlation among noises on the normalized intensity correlation function C(s).C(s) is derived by means of the projection operator method. 相似文献
24.
姚奎 《浙江大学学报(理学版)》1999,(1)
本文考虑用TchebychefFourier级数的ValéePousin平均逼近函数类Lipα,在f(x)∈C[-1,1]时获得了逼近阶及逼近误差的表达式,推广并较大地改进了文献[1,2]中的有关结果. 相似文献
25.
Frances Y. Jackson W. A. J. Luxemburg 《Proceedings of the American Mathematical Society》2003,131(1):185-199
We characterize the first three sundual spaces of , with respect to the translation group of .
26.
Jonathan M. Bennett Ana Vargas 《Proceedings of the American Mathematical Society》2003,131(1):117-127
We explore decay estimates for circular means of the Fourier transform of a measure on in terms of its -dimensional energy. We find new upper bounds for the decay exponent. We also prove sharp estimates for a certain family of randomised versions of this problem.
27.
曲文孝 《核聚变与等离子体物理》2000,20(3):129-135
在TFTR及TEXF等装置上观测到的边界电子冷脉冲的输运现象是通常基于局部热导的瞬态输运理论所无法解释的。利用一个与电子温度剖面不变性相「容的且与在ρ=ρL(ρL≈0.7~0.8)处的局部电子热导相关的非局部电子热导模型来描述边界冷脉冲引起的电子温度变化的瞬态过程,发现此模型可定性地解释边界冷脉冲实验现象的几乎所有主要特征。 相似文献
28.
Feng Dai 《Constructive Approximation》2005,22(3):417-436
Let $\sigma_k^\delta$ denote the Cesaro means of order $\delta > -1$ of the spherical harmonic expansions on the unit sphere $S^{d-1}$, and let $E_j(f, H^1)$ denote the best approximation of $f$ in the Hardy space $H^1(S^{d-1})$ by spherical polynomials of degree at most $j$. It is known that $\lambda:= (d-2)/2$ is the critical index for the summability of the Cesaro means on $H^1(S^{d-1})$. The main result of this paper states that, for $ f\in H^1(S^{d-1})$, $$\sum_{j=0}^N \f 1{j+1} \|\sigma_j^\lambda (f) -f\|_{H^1}\approx \sum_{j=0}^N \f 1{j+1} E_j(f, H^1),$$ where “$\approx$” means that the ratio of both sides lies between two positive constants independent of $f$ and $N$. 相似文献
29.
Essaid Zerrad Richard Triplett Anjan Biswas 《International Journal of Theoretical Physics》2009,48(6):1583-1588
A new numerical method of solving integro-differential equations appearing in the theory of atomic and nuclear scattering
systems has been devised. It is termed Singular Value Decomposition Method (SVD). It consists in expanding the exchange kernel
into a number of separable terms by means of the Singular Value Decomposition and then iterating over the remainder. In this
paper, we extend our SVD method to the scattering of low energy electron-helium which has been the subject of interest, both
theoretically and experimentally. We compare our results with the Moments Method which is widely used. The Moments Method
consists of making an expansion of the solution into an especially favorable basis that takes care of the non-exchange part
of the Hamiltonian. 相似文献
30.
We design a novel X-ray image detector by lens coupling a Gd2O2S:Tb intensifying screen with a high performance low-light-level (L3,which often means luminescence less than 10-3 Lux) image intensifier.Different coupling effects on imaging performance between zoom lens and fix-focus lens are analyzed theoretically.In experiment,for designing a detector of 15-inch visual field,the system coupled by zoom lens is of 12.25-1p/cm resolution,while the one with fix-focus lens is 10 lp/cm.The superiority of zoom lens is validated.It is concluded that zoom lens preserves the image information better than fix-focus lens and improves the imaging system's performance in this design,which is referential to the design of other optical imaging systems. 相似文献