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121.
122.
吡嗪化合物因其独特的结构及活性被广泛应用于制药、医学、化学等领域。水热法以水作为溶剂,具有绿色无污染、简单易操作等特点,是合成配合物的首选方法。本文以2,6-双(2-吡嗪基)吡啶-4-对苯甲酸(Hbppc)和CdCl2·2.5H2O为原料,用水热合成法合成了一例新型的配位化合物[Cd(bppc)(H2O)Cl]n,并运用单晶X射线衍射、红外光谱和拉曼光谱分析等手段对配合物的结构进行了表征,结果表明此配合物为一维链状结构。对自由配体2,6-双(2-吡嗪基)吡啶-4-对苯甲酸及配合物[Cd(bppc)(H2O)Cl]n进行荧光分析,结果表明所得配合物具有较好的荧光性质。 相似文献
123.
《Solid State Sciences》2012,14(3):401-408
We have predicted structural, electronic, elastic, thermodynamic and vibration characteristics of TbN, using density functional theory within generalized-gradient (GGA) apraximation. For the total energy calculation we have used the projected augmented plane-wave (PAW) implementation of the Vienna Ab initio Simulation Package (VASP). We have used to examine structure parameter in eight different structures such as in NaCl (B1), CsCl (B2), ZB (B3), Tetragonal (L10), WC (Bh), NiAs (B8), PbO (B10) and Wurtzite (B4). We have performed the thermodynamics properties for TbN by using quasi-harmonic Debye model. We have, also, predicted the temperature and pressure variation of the volume, bulk modulus, thermal expansion coefficient, heat capacities and Debye temperatures in a wide pressure (0–130 GPa) and temperature ranges (0–2000 K). Furthermore, the band structure, phonon dispersion curves and corresponding density of states are computed. Our results are compared to other theoretical and experimental works, and excellent agreement is obtained. 相似文献
124.
We study the curvature-induced bound states and the coherent transport properties for a particle constrained to move on a truncated cone-like surface. With longitudinal hard wall boundary condition, the probability densities and spectra energy shifts are calculated, and are found to be obviously affected by the surface curvature. The bound-state energy levels and energy differences decrease as increasing the vertex angle or the ratio of axial length to bottom radius of the truncated cone. In a two-dimensional (2D) GaAs substrate with this geometric structure, an estimation of the ground-state energy shift of ballistic transport electrons induced by the geometric potential (GP) is addressed, which shows that the fraction of the ground-state energy shift resulting from the surface curvature is unnegligible under some region of geometric parameters. Furthermore, we model a truncated cone-like junction joining two cylinders with different radii, and investigate the effect of the GP on the transmission properties by numerically solving the open-boundary 2D Schrödinger equation with GP on the junction surface. It is shown that the oscillatory behavior of the transmission coefficient as a function of the injection energy is more pronounced when steeper GP wells appear at the two ends of the junction. Moreover, at specific injection energy, the transmission coefficient is oscillating with the ratio of the cylinder radii at incoming and outgoing sides. 相似文献
125.
魏格纳函数在量子力学、量子光学、热力学和量子统计力学中有着重要的地位和非凡的作用,所以在量子力学中研究处于外电磁场中有结构的中性粒子的魏格纳函数具有很高的价值.本文首先介绍了的魏格纳函数的性质和应用,然后在对称规范下给出了极性原子的哈密顿量,最后通过Bopp变换求解了具有Moyal-Weyl星乘的能量本征方程,得到了处于电磁场中的中性极性粒子的能级和魏格纳函数. 相似文献
126.
在酸性条件下,溴化钠对NaIO4-H2O2-甲氧氯普胺弱化学发光具有增敏作用,结合流动注射技术建立了一种测定甲氧氯普胺的新方法。在优化实验条件下,相对化学发光强度与甲氧氯普胺的质量浓度在1.00×10-9~1.20×10-6g/mL范围内呈良好的线性关系,检出限为3.5×10-10g/mL,相对标准偏差(ρ=1.00×10-7g/mL,n=11)为2.5%。该方法已成功用于片剂及加标尿样中甲氧氯普胺含量的测定,回收率为96%~100%,与标准方法相对照,测定结果基本一致。 相似文献
127.
128.
Zhi-Feng Sun Lu-Nan Zhou Yifei Meng Tao Zhang Zhen-Ting Du Huaiji Zheng 《Tetrahedron: Asymmetry》2017,28(11):1562-1567
A concise asymmetric total synthesis of the sex pheromone of the tea tussock moth has been achieved from commercially available starting materials. The chiral moiety was introduced by Evans’ template and the key CC bond construction was accomplished through Julia-Kocienski coupling and Wittig olefination. The salient characteristic of our synthetic route is that it is protecting a group free. 相似文献
129.
The theoretical investigations of the interface optical phonons, electron–phonon couplings and its ternary mixed effects in zinc-blende spherical quantum dots are obtained by using the dielectric continuum model and modified random-element isodisplacement model. The features of dispersion curves, electron–phonon coupling strengths, and its ternary mixed effects for interface optical phonons in a single zinc-blende GaN/AlxGa1−xN spherical quantum dot are calculated and discussed in detail. The numerical results show that there are three branches of interface optical phonons. One branch exists in low frequency region; another two branches exist in high frequency region. The interface optical phonons with small quantum number l have more important contributions to the electron–phonon interactions. It is also found that ternary mixed effects have important influences on the interface optical phonon properties in a single zinc-blende GaN/AlxGa1−xN quantum dot. With the increase of Al component, the interface optical phonon frequencies appear linear changes, and the electron–phonon coupling strengths appear non-linear changes in high frequency region. But in low frequency region, the frequencies appear non-linear changes, and the electron–phonon coupling strengths appear linear changes. 相似文献
130.
Castor oil and ricinoleic acid (an isolate of castor oil) are environmentally friendly bio-based organic surfactants that have been used as capping agents to prepare nearly spherical cadmium sulfide quantum dots (QDs) at 230, 250 and 280 °C. The prepared quantum dots were characterized by Ultra violet–visible (UV–vis), Photoluminescence (PL), Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM) and X-ray diffraction (XRD) giving an overall CdS QDs average size of 5.14±0.39 nm. The broad XRD pattern and crystal lattice fringes in the HRTEM images showed a hexagonal phase composition of the CdS QDs. The calculated/estimated average size of the prepared castor oil capped CdS QDs for various techniques were 4.64 nm (TEM), 4.65 nm (EMA), 5.35 nm (UV–vis) and 6.46 nm (XRD). For ricinoleic acid capped CdS QDs, the average sizes were 5.56 nm (TEM), 4.78 nm (EMA), 5.52 nm (UV–vis) and 8.21 nm (XRD). Optical properties of CdS QDs showed a change of band gap energy from its bulk band gap of 2.42–2.82 eV due to quantum size confinement effect for temperature range of 230–280 °C. Similarly, a blue shift was observed in the photoluminescence spectra. Scanning electron microscope (SEM) observations show that the as-synthesized CdS QDs structures are spherical in shape. Fourier transform infra-red (FTIR) studies confirms the formation of castor oil and ricinoleic acid capped CdS QDs. 相似文献