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51.
Let G be a finite group. Fix a prime divisor p of IGI and a Sylow p-subgroup P of G, let d be the smallest generator number of P and Ma(P) denote a family of maximal subgroups P1, P2 , Pd of P satisfying ∩^di=1 Pi = Ф(P), the Frattini subgroup of P. In this paper, we shall investigate the influence of s-conditional permutability of the members of some fixed .Md(P) on the structure of finite groups. Some new results are obtained and some known results are generalized. 相似文献
52.
Cementations formed in geological timescale are observed in various stiff clays.A micromechanical stress strain model is developed for modeling the effect of cementation on the deformation behavior of stiff clay.The proposed approach considers explicitly cementations at intercluster contacts,which is different from conventional model.The concept of inter-cluster bonding is introduced to account for an additional cohesion in shear sliding and a higher yield stress in normal compression.A damage law for inter-cluster bonding is proposed at cluster contacts for the debonding process during mechanical loading.The model is used to simulate numerous stress-path tests on Vallericca stiff clay.The applicability of the present model is evaluated through comparisons between the predicted and the measured results.In order to explain the stress-induced anisotropy arising from externally applied load,the evolution of local stresses and local strains at inter-cluster planes are discussed. 相似文献
53.
利用作者根据饱和多孔介质动力学方程快、 慢纵波解耦求得的集中力作用下饱和多孔介
质Green函数解答, 通过柱坐标变换, 运用Sommerfeld积分, 再根据自由表面应力为零的特
征, 添加自由表面影响场, 从而求得半无限空间集中力作用下饱和多孔介质动力学问题的解
答. 其结果与Philippacopoulos解答结果一致; 当饱和多孔蜕化为单相时与Lamb的方程一
致. 整个推导过程明了, 物理意义也较为清晰; 方法符合常规解法. 因此, 该方法为简化与
规范饱和多孔介质动力学问题的解答提供了基础; 并且能为一直未解决的半无限空间饱和多
孔介质动力学问题的流相解答(诸如孔隙压、排水量)提供解决途径. 相似文献
54.
使用飞秒时间分辨抽运-探测透射光谱技术,实验研究了GaAs体材料中光激发载流子的超快弛豫动力学的波长依赖.在相同的光激发载流子浓度和抽运/探测比时,发现760 nm和780 nm两中心波长处的瞬态透射变化延迟扫描信号出现负的和振荡的信号.与模拟计算结果对比,判定该实验瞬态信号是错误的.分析探测器输出波形,发现是由于反相波形导致的,而引起反相波形的原因在于样品中存在长寿命的吸收过程.指出通过提高探测器上的抽运/探测比能够矫正反相波形,从而获得正确的瞬态透射变化动力学.提高探测器上的抽运/探测比与目前的应尽量减小抽运光对探测器的散射贡献的观点是对立的.文章的研究结果对应用抽运-探测时间分辨光谱技术正确地测量超快瞬态动力学过程具有重要的参考价值.
关键词:
时间分辨抽运-探测透射光谱
饱和吸收
吸收增强
GaAs体材料 相似文献
55.
The liquid phase acetolysis of epichlorohydrin (ECH) with acetic acid was studied over bentonite clay catalysts and was found
to be very active for the selective formation of 1-acetoxy-3-chloro-2-propanol. The reaction followed first order kinetics
with respect to epichlorohydrin and obeyed the Langmuir-Hinshelwood mechanism. 相似文献
56.
Ya‐Chen Chen 《Journal of Graph Theory》2009,61(2):111-126
A graph is C5‐saturated if it has no five‐cycle as a subgraph, but does contain a C5 after the addition of any new edge. We prove that the minimum number of edges in a C5 ‐saturated graph on n≥11 vertices is sat(n, C5)=?10(n?1)/7??1 if n∈N0={11, 12, 13, 14, 16, 18, 20} and is ?10(n?1)/7? if n≥11 and n?N0. © 2009 Wiley Periodicals, Inc. J Graph Theory 相似文献
57.
58.
Cordierite porous ceramics Z, X, and K were prepared using three mixtures of clay minerals: Z from kaolinite, talc, and aluminum
hydroxide, X from kaolinite, talc, vermiculite, and aluminum hydroxide, and K from kaolinite, talc, and magnesium oxide. Ceramics
were different in porosity, specific surface area, cordierite polymorphs, and secondary crystalline phases. Vermiculite influenced
textural architecture of calcined cordierite ceramics X and predestinated crystallization of the high-temperature hexagonal
α-cordierite with secondary minerals enstatite, spinel and corundum. Ceramics Z contained low-temperature orthorhombic β-cordierite,
enstatite, and corundum, K was diphase of β-cordierite and forsterite. Total pore area (TPA) and specific surface area (SSA)
of X, in spite of the higher porosity and the pore size distribution in the range of 300–1000 nm, were smaller in comparison
with TPA and SSA of Z. Ceramics K retained high porosity, two maxima at 300–1000 nm and 50–200 nm in the pores size distribution,
and the highest TPA and SSA compared to those observed in ceramics Z and X.
Presented at the 8th Conference on Solid State Chemistry, 6-11 July 2008, Bratislava, Slovak Republic. 相似文献
59.
The direct electrochemistry of glucose oxidase (GOD) was achieved based on the immobilization of GOD on a natural nano‐structural attapulgite (ATP) clay film modified glassy carbon (GC) electrode. The immobilized GOD displayed a pair of well‐defined quasi‐reversible redox peaks with a formal potential (E0′) of ?457.5 mV (vs. SCE) in 0.1 mol·L?1 pH 7.0 phosphate buffer solution. The peak current was linearly dependent on the scan rate, indicating that the direct electrochemistry of GOD in that case was a surface‐controlled process. The immobilized glucose oxidase could retain bioactivity and catalyze the oxidation of glucose in the presence of ferrocene monocarboxylic acid (FMCA) as a mediator with the apparent Michaelis‐Menten constant Kappm of 1.16 mmol·L?1. The electrocatalytic response showed a linear dependence on the glucose concentration ranging widely from 5.0×10?6 to 6.0×10?4 mol·L?1 (with correlation coefficient of 0.9960). This work demonstrated that the nano‐structural attapulgite clay was a good candidate material for the direct electrochemistry of the redox‐active enzyme and the construction of the related enzyme biosensors. The proposed biosensors were applied to determine the glucose in blood and urine samples with satisfactory results. 相似文献
60.