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141.
Gas-phase CS2 activation by M+ (M = Ta, W, Re) was studied by the B3LYP density functional method.The geometries for reactants, transition states, and products were completely optimized. CS2 activation mediated by M+ (M = Ta, W, Re) were found to be a spin-forbidden process as a result of the crossing among the multistate energetic profiles. On the basis of the Hammond postulate, this was a typical two-state reactivity reaction. Among the different potential energy surfaces, the crossing points had been explored. The spin–orbit coupling (SOC) was also calculated between the electronic states of different multiplicities at the crossing point to estimate the intersystem crossing probability. For CP1, CP2, and CP4, the computed SOC constants were 80.28, 128.65, and 526.77 cm?1, which obtained by using one-electron spin–orbit Hamiltonian in Gaussian 09. 相似文献
142.
143.
Presently, we develop a simplified corticothalamic(SCT) model and propose a single-pulse alternately resetting stimulation(SARS) with sequentially applying anodic(A, "+") or cathodic(C, "-") phase pulses to the thalamic reticular(RE) nuclei,thalamus-cortex(TC) relay nuclei, and cortical excitatory(EX) neurons, respectively.Abatement effects of ACC-SARS of RE, TC, and EX for the 2 Hz–4 Hz spike and wave discharges(SWD) of absence seizures are then concerned. The m∶n on-off ACC-SARS protocol is sh... 相似文献
144.
It is commonly accepted that realistic networks can display not only a complex topological structure, but also a heterogeneous distribution of connection weights. In addition, time delay is inevitable because the information spreading through a complex network is characterized by the finite speeds of signal transmission over a distance. Weighted complex networks with coupling delays have been gaining increasing attention in various fields of science and engineering. Some of the topics of most concern in the field of weighted complex networks are finding how the synchronizability depends on various parameters of the network including the coupling strength, weight distribution and delay. On the basis of the theory of asymptotic stability of linear time-delay systems with complex coefficients, the synchronization stability of weighted complex dynamical networks with coupling delays is investigated, and simple criteria are obtained for both delay-independent and delay-dependent stabilities of the synchronization state. Finally, an example is given as an illustration testing the theoretical results. 相似文献
145.
146.
Wu Daming Meng Qingyun Liu Ying Ding Yumei Chen Weihong Xu Hong Ren Dongyun 《Journal of Polymer Science.Polymer Physics》2003,41(10):1051-1058
An in situ bubble‐stretching (ISBS) model has been proposed on the basis of an analysis of the dispersion process of inorganic additives in polymers. The ISBS model is applicable to a dispersion of solid granular aggregates in polymer melts because the dispersed phase itself serves as a nucleation agent, giving rise to bubbles that expand at the surface of the microgranules and their aggregates. In terms of bidirectional stretching, the ISBS process can increase the degrees of freedom of granule dispersion, which favors more homogeneous dispersion. According to theoretical predictions and indirect experimental estimations of the dispersion of nanoscale CaCO3 and nanoscale hydrotalcite in high‐density polyethylene (HDPE), when the bubble expands, the stretching rate of the polymer melt on the bubble wall can reach 105–106 s?1. The field emission scanning electron microscopic images indicated that the granular size of dispersed CaCO3 and hydrotalcite in HDPE with the ISBS method is about 60–80 nm, two orders of magnitude smaller than that attained with a shearing rate of 103 s?1 in a capillary rheometer. It is also predicted that elastic bubble oscillations may be generated through suitable control of process parameters and that their oscillatory frequency can be in the ultrasound range. This type of bubble oscillation can also promote dispersion. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1051–1058, 2003 相似文献
147.
基于吴方法的立体视觉方法 总被引:1,自引:0,他引:1
本文把机器证明的吴方法创造性地应用到立体视觉领域。给出了线画图对间边线型匹配约束条件、轮廓线型对应约束条件以及曲线型约束条件,并由此给出了重建三维景物的一种整体立体视觉方法,理论分析和实验结果都表明此方法具有速度快、精度高等特点。 相似文献
148.
The mechanism of the cyclic reaction N2O(1∑) + CO(1∑+) → N2(1∑ g + ) + CO2(1∑ g + ) catalyzed by Re+ has been investigated on quintet and septet potential energy surfaces (PES). The reactions were studied by the B3LYP density functional method and the CCSD(T) theory. The calculated results of different PES show that the reaction proceeds in a two-step manner and spin crossing between different PES occurs. The involving crossing points (CPs) between the quintet and septet PES have been discussed by means of the intrinsic reaction coordinate approach. And the O-atom affinities testified that Re+ can capture O from N2O and transfer O atom to CO in the two spin state, which are thermodynamically allowed. Furthermore, the spin–orbit coupling (SOC) is calculated between electronic states of different multiplicities at the CPs. For CP1 and CP2, the computed SOC constants are 8.34 and 10.09 cm?1, respectively, obtained by using one-electron spin–orbit Hamiltonian in GAMESS. Therefore, the intersystem crossing at CP1 and CP2 occurs with a little probability because of the small SOC involved. 相似文献
149.
详细报道了以工业布龙酸(2-氨基-6-萘磺酸)为原料合成染料中间体2-氨基-6-萘磺酰甲胺的方法,对反应条件进行了研究,产物经元素分析、红外、核磁、质谱测定,与结构相符,并用液相色谱分析了产品的纯度. 相似文献
150.
With increasing public attention on product quality, supply chain quality management has been the focus of considerable research attention in recent years. However, only a few published articles have considered reference effects in supply chain quality management. In practice, reference effects influence consumer purchasing behaviours. Therefore, we have developed a dynamic model that incorporates the effects of the reference quality and reference price on the demand function of a ‘single-supplier single-manufacturer’ supply chain system. In our model, the demand function is assumed to be influenced by the reference price and reference quality. The reference price formation is assumed to be affected by the gap between quality and the reference quality. By utilizing differential game theory, we calculate and compare the open-loop equilibrium quality levels in two different scenarios: (i) Each channel member makes decisions within a subsidy programme and (ii) the supplier vertically integrates with the manufacturer. In addition, a total cost-sharing contract based on quality improvement efforts is proposed and proven to be effective in the supply chain system that is under consideration. 相似文献