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排序方式: 共有4458条查询结果,搜索用时 15 毫秒
861.
ABSTRACT Azo dyes are a group of chemical moieties joined by azo (-N=N-) group with potential usefulness in different industrial applications. But these dyes are not devoid of hazardous consequence because of poor affinity for the fibre and discharge into the water stream. The chemical aspects of 72 azo dyes towards cellulose fibre in terms of their affinity by QSPR have been explored in the present work. We have employed two approaches, namely balance of correlation without IIC (TF1) and balance of correlation with IIC (TF2), to generate 16 QSAR models from 8 splits. The determination coefficient of calibration and validation set was found higher when the QSPR models were developed using the index of ideality correlation (IIC) parameter (TF2). The model developed with TF2 for split 3 was considered as a prominent model because the determination coefficient of the validation set was maximum (r 2 = 0.9468). The applicability domain (AD) was also analysed based on ‘statistical defect’, d(A) for a SMILES attribute. The mechanistic interpretation was done by identifying the SMILES attributes responsible for the promoter of endpoint increase and promoter of endpoint decrease. These SMILES attributes were applied to design 15 new dyes with higher affinity for cellulose fibre. 相似文献
862.
863.
864.
Yu. Vassilevski 《Numerical Linear Algebra with Applications》2004,11(4):327-341
A new two‐level black‐box preconditioner based on the hybrid domain decomposition technique is proposed and studied. The preconditioner is a combination of an additive Schwarz preconditioner and a special smoother. The smoother removes dependence of the condition number on the number of subdomains and variations of the diffusion coefficient and leaves minor sensitivity to the problem size. The algorithm is parallel and pure algebraic which makes it a convenient framework for the construction parallel black‐box preconditioners on unstructured meshes. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
865.
Bernd Flemisch Barbara I. Wohlmuth 《Numerical Methods for Partial Differential Equations》2004,20(3):374-387
A one directionally coupled problem on two nested domains is analyzed. The global domain and the subdomain are discretized by two triangulations that do not match on the subdomain. The connection between the two grids is established by using a stable projection operator onto the interface. An a priori error analysis is carried out and several numerical examples are given. The method is ideally suited for the case of a moving subdomain. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 20: 374–387, 2004. 相似文献
866.
椭圆芯手征光纤的基模特性研究 总被引:4,自引:1,他引:3
对椭圆芯手征光纤进行了严格的求解,得到了模式场的解析解;推了了模式特征方程;并对基模的偶模和奇模特征方程进行数值求解,研究了手征参数对不同椭圆比下基模的色散曲线,双折射,模间色散等特性的影响。 相似文献
867.
Diffusion theory of slow responses 总被引:1,自引:0,他引:1
When an action is applied to a macroscopic substance, there is a particular sort of slow response besides the well-known fast
response. Using diffusion theory, the characteristics of slow response in dielectric, elastic, piezoelectric, and pyroelectric
relaxation may be explained. A time domain spectroscopy method suitable for slow and fast responses in linear and nonlinear
effects is given. Every relaxation mechanism contributes a peak in differential spectroscopy, and its position, height, and
line shape show the dynamical properties of the mechanism. The method of frequency domain spectroscopy is suitable only for
linear fast response. Time domain spectroscopy is another nonequivalent powerful method. The theory is confirmed by a lot
of experimental data.
Project supported by the National Natural Science Foundation of China and the Science Foundation of Zhongshan University. 相似文献
868.
非重叠区域分解算法在于建立和求解相关的界面方程.建立界面方程在理论上虽。然容易推导,例如某些问题可用Gauss块消去法,但在实际计算时并不可行,所以界面方程在一些算法中是陷式的.而求解界面方程一般要进行预处理,本提出一种区域分解算法,可得出界面方程的显式表达.算法是完全并行的,所得出的界面方程的系数矩阵的条件数已与网参数无关,事实上就是(Sh^(1))^-1Sh,进而可直接用收敛速度较快的Chebyshev加速算法求解该界面方程,在充分应用并行计算方法的条件下,本算法与[4]中的算法相比计算效率提高. 相似文献
869.
M. Naftaly A. P. Foulds R. E. Miles A. G. Davies 《International Journal of Infrared and Millimeter Waves》2005,26(1):55-64
Terahertz time-domain spectroscopy is used to study properties of non-polar materials. Terahertz absorption spectra and refractive indices are measured in a number of glasses, lubricating oils, and types of paper. The results are correlated with material properties. 相似文献
870.
Kurt Engesser 《Mathematical Logic Quarterly》1995,41(1):49-64
We study modal logics based on neighbourhood semantics using methods and theorems having their origin in topological model theory. We thus obtain general results concerning completeness of modal logics based on neighbourhood semantics as well as the relationship between neighbourhood and Kripke semantics. We also give a new proof for a known interpolation result of modal logic using an interpolation theorem of topological model theory. 相似文献