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Hirofumi Hirayama Toshihiro Itoh Yoshihiko Nakaki Takahiko Yoshida 《Artificial Life and Robotics》2005,9(3):144-160
A mathematical method is introduced to characterize the electrokinetic behavior (electrophoresis) of a biomolecular particle which passes through a specific channel pore on an excitable biological membrane. The basic approach was first proposed by Booth (1950). The system was described by an equation of continuity and an equation of motion in which the driving force involves the diffusion effect, the hydrostatic pressure, and the electrostatic potential. By assuming linear relations between the velocity and the applied electrical field, solutions for the potential, pressure, and velocity were given by a series expansion of the charges on the particle. To examine the influence of ions surrounding the particle and forming an ionic cloud, the Debye–Huckel parameter was introduced. As the thickness of the double layer around the particle increased, the potential, velocity, pressure, and viscosity were changed significantly. The maximum influence was obtained when the radius of the particle became equal to the thickness of the double layer. Although this theory is valid for a charged, spherical, nonconducting particle only, the method is available for evaluating the kinetic behavior of a biomolecule that passes through a channel pore on a cellular membrane.This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003 相似文献
2.
茶乳酪分子间氢键与抗过敏分子轨道研究 总被引:1,自引:0,他引:1
应用CNDO/2法研究茶乳酪分子间氢键与抗过敏性的关系.结果表明执过敏性与条乳酪HOMO能量有正变关系。分子间氢键可增加茶环与嘌呤环的共平面。PMO分析表明共平面性可使HOMO具有较高能量,故认为条乳酪可能以电子给予体的形式与酶作用,是茶乳酪产生显著生物学效应的基本条件。 相似文献
3.
HMO法是分子轨道法中一个简化的近似计算方法。它主要应用于共轭分子。由于HMO法比较简单,并且从中还可提供一些有用的物理图象便于直观讨论结构和性能的关系,故为有机化学工作者易于接受。在此,本文将介绍HMO法的基本原理,并结合当前有机化学的教学来说明它在某些方面的应用。 相似文献
4.
Holger Kleinke 《Journal of Alloys and Compounds》1998,270(1-2)
The ternary antimonides Hf6M1−xSb2+x (M=Fe, Co, Ni) were prepared by arc-melting of stoichiometric mixtures of Hf, HfSb2 and M. According to the single crystal structure analyses, performed on Hf6NiSb2 and Hf6Ni0.76Sb2.24, Hf6M1−xSb2+x crystallizes in an ordered variant of the Fe2P structure type with the M and Sb atoms occupying the two P positions on 1b and 2c of space group P
2m, respectively (Zr6CoAl2 type). The 3d metal atoms M can partially be replaced by antimony, leading to significant, anisotropic changes in the lattice dimensions which are a=765.6(1) pm, c=362.10(7) pm, V=183.81(5)×106pm3 for Hf6NiSb2, and a=760.5(1) pm, c=372.40(7) pm, V=186.53(5)×106pm3 for Hf6Ni0.76Sb2.24 as determined by single crystal data. Calculations of the electronic structure of Hf6NiSb2 using the Extended Hückel approximation show strong bonding Hf–Hf, Hf–Ni, and Hf–Sb interactions. 相似文献
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In two previous papers (Kinget al., J. Organomet. Chem.
19, 327, 1969; Pannellet al., Organometallics
9, 859, 1990), the synthesis and X-ray structure of the two tetramethyl disilyl complexes [(5-C5H5) Fe(CO)2]2Si2Me4 (I) and Si2Me4[(5-C5H4) Fe(CO)2CH3]2 (II) were reported. ComplexII is obtained fromI [2]. However, attempts to form other derivatives fromI have generally failed. In the chemical process to getII fromI, an intermediate complex, Si2Me4[(5-C5H4) Fe(CO)2]
2
2–
(III), is probably formed. This is similar to complexII without the two methyl groups bonded to the Fe atoms. Therefore, a theoretical study that may shed some light on the intermediate structure, stability, and reactivity is justified. We have developed theoretical studies consisting of extended Huckel electronic structure calculations on the simulated intermediate geometry. The results obtained from these calculations suggest that it might be stable enough to form during reactions of complexI. The more reactive sites, which suggest reaction alternatives, are pointed out.Presented at the XXVIth Silicon Symposium, Indiana University-Purdue University at Indianapolis, March 26–27, 1993.On sabbatical leave from Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa, 09340 D.F., México. 相似文献
6.
朱云 《西安工业学院学报》1989,(1)
本文应用休克尔分子轨道(HMO)理论,计算了α,β自由基分子轨道的能量,比较了它们的稳定性,进而说明了α-卤代反应优先发生的原因。 相似文献
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