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Intermolecular nuclear relaxation studies of real liquids and the results of theoretical calculations for model potential functions have provided significant information on the role of molecular interactions in the structure of liquids. The intermolecular proton-proton paircorrelation function (pcf), obtained from the reference interaction site model (RISM) is used as the equilibrium distribution and is used to obtarn an effective force for the calculation of intermolecular proton relaxation rates in liquid benzene, 1,3,5-trideuterobenzene and ethane. For liquid ethane, better agreement with experiment is observed with the pcf obtained from the Monte Carlo simulation than with the RISM result. 相似文献
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Bo-Cheng Wang Likey Chen Kuei-Jen Lee Chang-Yuan Cheng 《Journal of Molecular Structure》1999,469(1-3):127-134
The spectral analysis indicates that all isomers of C60O, C70O and C60O2 have an epoxide-like structure (an oxygen atom bridging across a C–C bond). According to the geometrical structure analysis, there are two isomers of fullerene monoxide C60O (the 5,6 bond and the 6,6 bond), eight isomers of fullerene monoxide C70O and eight isomers of fullerene dioxide C60O2. In order to simulate the real reaction conditions at 300 K, the calculation of the different isomers of C60O, C60O2 and C70O fullerene oxides was carried out using the semiempirical molecular dynamics method with two different approaches: (a) consideration of the geometries and thermodynamic stabilities, and (b) consideration of the ozonolysis mechanism. According to the semiempirical molecular dynamic calculation analysis, the probable product of this ozonolysis reaction is C60O with oxygen bridging over the 6–6 bond (C2v). The most probable product in this reaction contains oxygen bridging across in the upper part of C70 (6–6 bond in C70O-2 or C70O-4) an epoxide-like structure. C60O2-1, C60O2-3 and C60O2-5 are the most probable products for the fullerene dioxides. All of these reaction products are consistent with the experimental results. It is confirmed that the calculation results with the semiempirical molecular dynamics method are close to the experimental work. The semiempirical molecular dynamics method can offer both the reaction temperature effect by molecular dynamics and electronic structure, dipole moment by quantum chemistry calculation. 相似文献
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Using an improved approximate formula to the centrifugal term, we present arbitrary l-state scattering solutions of the hyperbolic potential. The approximate analytical formula of scattering phase shifts and normalized wavefunctions are presented. All data calculated by the above approximate analytical formula are compared with those obtained by using the numerical integration method in the scattering state cases. We find that this improved approximate formula is better than previous one since the calculated results are in good agreement with those exact ones. 相似文献
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Graphene oxide (GO) was synthesized by an improved Hummers method and then reduced with NaBH4; GO became rGO with regular layered structure. Polyaniline (PANI)/rGO composite was prepared by a adsorption double oxidant method with rGO as a template. Some physical characterization methods (Fourier transform infrared spectroscopy analysis, X-ray diffraction, scanning electron microscope, and transmission electron microscope) were used to analyze the morphology and crystallinity of the composite. The electrochemical properties were characterized by cyclic voltammetry, impedance spectroscopy, galvanostatic charge/discharge, and rate capability. The first discharge specific capacity of the rPANI/rGO and PANI/rGO was 181.2 and 147.8 mAh/g. After 100 cycles, the capacity retention rate was still 90.2 and 88.9% separately, and the coulombic efficiency of batteries is close to 100%. These results demonstrate the composite has exciting potentials for the cathode material of lithium-ion battery. 相似文献
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采用水热法制备了ZnO和不同掺杂浓度的ZnO:Cd纳米棒,通过SEM,XRD、拉曼光谱等的分析,研究了ZnO和ZnO:Cd的微结构并测试分析了其光致发光特性.结果表明,ZnO和ZnO:Cd纳米棒呈六角纤锌矿结构,Cd掺杂使得纳米棒体积更小.由于内部张应力的影响,Cd掺杂使得材料光学带隙减少.当掺杂浓度为2%时,合成的材料光致发光谱中出现了位于2.67 eV处,由导带底和Zn空位(VZn)缺陷能级跃迁造成的蓝光发射峰,并且Cd的掺入使得位于2.90 eV附近的紫光发射峰强度增强,对于研究ZnO蓝紫发光器件具有重要的意义. 相似文献
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Li-Hua Gan Qing Chang Li Xu Zuo-Hua Liu Jun Du Chang-Yuan Tao 《Structural chemistry》2012,23(3):711-715
The carbon cages composed of pentagons and heptagons (F5F7 isomers) are the analogs of fullerenes composed of pentagons and hexagons (F5F6 isomers). To provide insight into the structures and stability of the hydrides of F5F6 and F5F7 isomers, systematical density functional theory calculations are performed on all the 1,812 F5F6–C60H60 and 56 F5F7–C60H60. The calculated results demonstrate that the isomer with lowest/highest energy has most/fewest fused pentagons for both F5F6 and F5F7 hydrides and the stability of these hydrides increase with the number of fused pentagons roughly. The lowest energy F5F6–C60H60 and F5F7–C60H60 are 237.1 and 152.5 kcal/mol lower in energy than the isolated pentagon rule (IPR) C60H60, respectively; however, these two parent cages are 529.6 and 660.0 kcal/mol higher in energy than the IPR C60. The calculations suggest that heptagon-containing cages, not only those violating the IPR can be the candidate cages for
fullerene derivatives and the possible repulsion between the added atoms may play an important role in determining the structures
and stability of the hydrides of carbon cages. 相似文献
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In this paper, exact solutions of scattering states of the Klein-Gordon equation with Coulomb potential plus
a new ring-shaped potential are studied under the condition that
the scalar potential is equal to the vector potential. The normalized
wave functions of scattering states on the “k/2π scale” and the calculation formula of phase shifts are presented. Analytical properties of the scattering amplitude are discussed. 相似文献
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We present a new approximation scheme for the centrifugal term,and apply this new approach to the Schrdinger equation with the modified Pschl-Teller potential in the D-dimension for arbitrary angular momentum states.The approximate analytical solutions of the scattering states are derived.The normalized wave functions expressed in terms of the hypergeometric functions of the scattering states on the k/2π scale and the calculation formula of the phase shifts are given.The numerical results show that our results are in good agreement with those obtained by using the amplitude-phase method(APM). 相似文献