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1.
Absolute total electron scattering cross sections for carbon dioxide have been measured at low electron energies using a photoelectron
source. The measurements have been carried out at 27 electron energies varying from 0.91–9.14 eV with an accuracy of ±3%.
The cross sections obtained in the present experiment have been compared with other measurements and theoretical computations. 相似文献
2.
There is a high correlation between molecular surface area (TSA) of triorganotin and triorganolead compounds and their toxicity towards a bacterium (Escherichia coli) and an alga (Selenastrum capricornutum). Parallel attempts to correlate other Group IVA organometals incorporating silicon or germanium were unsuccessful. It was further demonstrated, however, that a high correlation was obtainable between certain series of compounds with the same organic substituent but different metal centers involving all Group IVA elements. In both instances, the inability to obtain a quantitative structure-activity relationship (QSAR) for all systems studied appears to be a function of the solubility of the compounds. While organotin TSA values have been found to correlate well with their toxicities toward various organisms, this study clearly suggests that this type of QSAR can be readily extended to include other organometal systems, provided that there is no solubility problem and the toxicity is a function of the hydrophobicity of the organometal compounds. 相似文献
3.
The generalized Mycielskians (also known as cones over graphs) are the natural generalization of the Mycielski graphs (which were first introduced by Mycielski in 1955). Given a graph G and any integer m?0, one can transform G into a new graph μm(G), the generalized Mycielskian of G. This paper investigates circular clique number, total domination number, open packing number, fractional open packing number, vertex cover number, determinant, spectrum, and biclique partition number of μm(G). 相似文献
4.
刘国志 《数学的实践与认识》2006,36(12):1-5
提出一个新的具有积压定单的关于模糊订购量的模糊存储模型.在模糊函数原理下,给出了模糊总存储成本.为了寻找最优解,把最优模糊存储模型转化为双目标最优化模型,利用L ingo8.0求解不等式约束问题,我们发现最优解都是确定的实数.此外,当模糊订购量和模糊总需求都是三角形(或权重均为1/2梯形)模糊数时,我们提出模型的最优解与经典的具有积压定单存储模型具有相同的结果. 相似文献
5.
Applied Biochemistry and Biotechnology - 相似文献
6.
给定一组工件的加工时间与工期,要求确定这些工件在一台机器上的加.工排列,使相应的总延误达到最小,这就是总延误问题.该问题在近年已被证明是NP困难的.由Wilkermn和Irwin(1971),林勋(1983)等所研究的顺时安排法能得到相邻交换意义下的局部解.在本文中,我们进一步证明该算法能得到前移邻域意义下的局部解,并确定了该算法的性能比. 相似文献
7.
全变差有界函数列的一致(R)可积性 总被引:4,自引:0,他引:4
给出了一致有界单调函数列一致可积性定理 ,由此得出全变差序列有界的收敛函数列的一致可积性 .说明了该结论可判断一些非一致收敛函数列的逐项积分性质 . 相似文献
8.
Theoretical concerns about the use of cemented and press-fit stems in revision total knee arthroplasty (TKA) include stress
shielding with adverse effects on prosthesis fixation. Radiological studies have showed distal femoral bone resorption after
revision TKA. The revision with use of stems can place abnormal stresses. These stresses can promote the effect of bone stress
shielding and may contribute to bone loss. Experimental quantification of strain shielding in the distal synthetic femur following
TKA is the main purpose of the present study. Three different constructs of TKA were assessed. The first construct included
a stemless femoral component. The other two included a press-fit and a cemented femoral stem. Cortical bone strains were measured
experimentally with tri-axial strain gauges in synthetic femurs before and after in-vitro knee surgery. The difference between
principal strains of implanted and intact femur was calculated for each strain gauge position. This study indicates that the
use of stems in distal femur changes the distribution and magnitude of bone strains. The press-fit stem provoked relevant
bone area (stem length) subjected to strain shielding and also originated the highest reduction of strains in the distal region,
which can potentially induce bone resorption. The stemless implanted femur produced minor bone strain changes relatively to
the intact femur. The use of distal femur stems increases initial stability in the bone, but the observed reduction of strains
in this region, relative to the intact femur, provokes strain shielding that can induce bone resorption and may compromise
the long term implant stability. 相似文献
9.
10.
一个图G的全色数χT(G)是使得V(G)∪E(G)中相邻或相关联元素均染不同颜色的最少颜色数.文中证明了,若图G只有唯一的一个4度最大度点,则χT(G)=Δ(G)+1. 相似文献