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71.
An efficient method for computing the quantum theory of atoms in molecules (QTAIM) topology of the electron density (or other scalar field) is presented. A modified Newton–Raphson algorithm was implemented for finding the critical points (CP) of the electron density. Bond paths were constructed with the second‐order Runge–Kutta method. Vectorization of the present algorithm makes it to scale linearly with the system size. The parallel efficiency decreases with the number of processors (from 70% to 50%) with an average of 54%. The accuracy and performance of the method are demonstrated by computing the QTAIM topology of the electron density of a series of representative molecules. Our results show that our algorithm might allow to apply QTAIM analysis to large systems (carbon nanotubes, polymers, fullerenes) considered unreachable until now. © 2012 Wiley Periodicals, Inc.  相似文献   
72.
73.
The electron energy distribution function (EEDF) for a magnetically filtered dusty plasma is studied in a dusty double plasma device where the electron energy can be varied from 0.15 eV to ~ 2.8 eV and plasma density from 10 6 cm-3 to 10 9cm-3 . The characteristics of EEDF for these ranges of plasma parameters are investigated in a pristine plasma as well as in a dusty plasma. The results show that in the presence of dust, there is a drastic modification in EEDF patterns in a plasma with higher electron temperature and density than those in a low temperature and low density plasma produced by the magnetic filter.  相似文献   
74.
The recent study of He and You [P.-S. He and W.-L. You, Int. J. Mod. Phys. B26, 1250107 (2012)] on the relation between superfluid and condensate densities in a two-dimensional weakly interacting Boson system assumed a δ(x???x′) interaction between two particles at sites x and x′. The main purpose of this article is to point out the sensitivity of the conclusions of He and You to the choice of interaction. Thus, it is known for logarithmic interactions that one can have superfluidity without a condensate. Finally, some related ideas are mentioned in relation to superfluidity in liquid 4 He at exceedingly low temperatures.  相似文献   
75.
《合成通讯》2012,42(24):3510-3527
Abstract

A series of novel indoline-(thio)urea were designed and prepared using indoline(s) as a new platform and tested as organocatalysts in the Michael and Morita–Baylis–Hillman reactions. Most of the compounds were found to be very active catalysts although they did not promote the enantioselectivity. As agents for the conversion of thiocarbonyl compounds into carbonyl compounds, potentials of PIFA and DDQ were also displayed. Furthermore, DFT calculations rationalized the experimentally observed non-enantioselectivity of the catalysts.  相似文献   
76.
Four MnIII-porphyrin complexes, chloro(tetraphenylporphinato)MnIII(1,6-diaminohexane), bromo(tetraphenylporphinato)MnIII(1,6-diaminohexane), azido(tetraphenylporphinato)MnIII(1,6-diaminohexane), and thiocyanato(tetraphenylporphinato)MnIII(1,6-diaminohexane), have been synthesized. These complexes have been characterized using UV-Vis, IR, ESI-mass spectra, elemental analyses, magnetic susceptibility measurements, and conductivity measurement. The molar conductance values of these complexes in ethanol indicate non-electrolytes. The utility of these complexes in de-polymerization of coal using humic acid as the coal model has been tested by the optical density method.  相似文献   
77.
The nonhydrolyzable fluorescent diether analog of phosphatidylcholine, 1-O-hexadecyl-2-0-pyrenedecyl-sn-glycero-3-phosphocholine, has been synthesized as a stable probe for the determination of phospholipid transfer to different lipoprotein classes with potential phospholipase activities. After incubation of total human serum with the new probe at 37°C for 3 hours a characteristic partition equilibrium between the main lipoprotein fractions was observed. The fluorescent lipid was not degraded under these conditions and, therefore, served as a marker for choline glycerophospholipid distribution between and transport to serum lipoproteins.  相似文献   
78.
本文研究了MgB4O7中Ce^3+,Mn^2+光致发光性质与浓度的关系,并讨论了Ce^3+→Mn^2+能量传递的机理。  相似文献   
79.
 专门设计了用脉冲-回波-重合法在不同静水压下测量液体声速的装置,并对石油醚在0.1~650 MPa流体静压力范围内测量了其超声声速和衰减系数。还通过测量体积压缩量和质量得到石油醚密度ρ随流体静压力的变化。最后,给出了石油醚的绝热压缩系数β与流体静压力的关系。  相似文献   
80.
从具有随机频率与随机相位的随机谐和函数出发,证明了当随机频率与相位均为均匀分布而随机幅值与功率谱密度平方根成正比时,该随机过程的功率谱即精确地等于目标功率谱.进而表明:只需遍历频率区间,即可由单一谐和函数激励下的响应幅值给出响应的功率谱密度,从而揭示了虚拟激励法的物理意义.研究还表明:为了给出结构响应的功率谱密度,实际...  相似文献   
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