导电高聚物的EXAFS 研究(Ⅰ)铂氯酸(H2PtCl6·6H2O)掺杂的聚乙炔

在实验室EXAFS装置上测量了一种导电高聚物——H_2PtCl_6·6H_2O掺杂聚乙炔和模型化合物(K_2PtCl_6)的PtL_Ⅲ吸收谱。用高功率的施转阳极靶X射线发生器(RigakuRU-1000)作为X射线源。观测到的EXAFS数据分析表明, Pt原子在试样中有两种配位状态。一种是PtCl_6~(2-)离子, Pt—Cl键长为0.233 nm, 另一种是Pt在0.228 nm附近有两个最近邻的Cl原子。实验结果提供了支持下述观点的直接结构信息: 随着电子从(CH)_x链向铂盐的转移, 发生下列反应:2H_2PtCl_6+2e~-→PtCl_6~(2-)+PtCl_2+4HCl     

退火对Ga_2O_3薄膜特性的影响

采用金属有机物化学气相沉积法在c面蓝宝石衬底上生长了高质量的β-Ga_2O_3薄膜,并将样品分别在真空、氧气、氮气氛围下退火30 min,研究了各类退火工艺对Ga_2O_3薄膜特性的影响,对退火所得的薄膜进行了X射线衍射、光致发光谱、紫外透射谱和原子力显微镜扫描的研究。结果表明,各类退火工艺均能够优化薄膜的晶体质量和表面形貌,同时有效改善了薄膜的光学性质。其中,氧气退火后的样品在可见光波段透射率高达83%,且吸收边更加陡峭;表面粗糙度降至0.564 nm,其表面更为平整。这些结果说明氧气退火对晶体质量的提高最为显著。氮气、真空退火的样品在光致发光谱中出现365 nm的发光峰,这是大量氧空位的存在导致的。     

NEPE推进剂贮存寿命预估方法的比较

在密闭条件下,对两种NEPE推进剂(NA -1和NP -1)进行了不同温度(55、65、75、85、95℃)的加速老化.跟踪测定了质量损失、拉伸强度和有效安定剂含量.分别以质量损失和拉伸强度为变化参量,以质量损失1％所需时间(τ)作为安全贮存寿命的临界点,以拉伸强度下降至0.5 MPa所需时间(τ')作为力学老化寿命的...     

Particle-in-cell simulation of ion-acoustic solitary waves in a bounded plasma

We study some nonlinear waves in a viscous plasma which is confined in a finite cylinder.By averaging the physical quantities on the radial direction in some cases,we reduce this system to a simple one-dimensional model.It seems that the effects of the bounded geometry(the radius of the cylinder in this case)can be included in the damping coefficient.We notice that the amplitudes of both Korteweg–de Vries(KdV)solitary waves and dark envelope solitary waves decrease exponentially as time increases from the particle-in-cell(PIC)simulation.The dependence of damping coefficient on the cylinder radius and the viscosity coefficient is also obtained numerically and analytically.Both are in good agreement.By using a definition,we give a condition whether a solitary wave exists in a bounded plasma.Moreover,some of potential applications in laboratory experiments are suggested.     

Synthesis,crystal structure and electrocatalytic behavior of a copper (II) complex derived from acylpyrazolone double Schiff bases

A new double Schiff base complex, Cu(PMαFP)₂en (HPMαFP = 1‐phenyl‐3‐methyl‐4‐(2‐furoyl)‐5‐pyrazolone, en = ethylenediamine), has been synthesized and characterized by elemental analysis, IR, UV, fluorescence spectra, thermal analysis, X‐ray single crystal diffraction and cyclic voltammetry (CV). Its crystal structure is monoclinic with space group Pbca and cell parameters: a = 22.263(3)Å, b = 13.671(2)Å, c = 10.0920(16)Å, Z = 4, S = 1.028, R₁ = 0.0500 and wR₂ = 0.1285. It was found that the Cu²⁺ ion is located in the coordination center. The Cu(II) has a slightly distorted plane quadrilateral coordination environment with two oxygen atoms and two nitrogen atoms of double Schiff base ligand in the equatorial plane. The complex has a one‐dimensional chain supramolecular structure, which is connected by C H…N bonding interactions. In the electrochemical experiments, the CV curve displays an oxidation peak in the presence of uric acid with Ep = 0.216V in pH = 7.0, showing that the Cu(PMαFP)₂en/glassy carbon modified electrode has an electrocatalytic activity toward uric acid.     

The effect of boron nitride nanotubes size on the HArF interaction by NBO and AIM analysis

Three molecules HArF@BNNT(5,0), HArF@BNNT(6,0), and HArF@BNNT(7,0) have been formed by HArF encapsulated in boron nitride nanotubes (BNNTs) with different sizes. Due to the interaction between the HArF and the BNNTs, the H? Ar bond lengths are in a decrease trend, while the Ar? F bond lengths are in an increase trend compared with those of HArF. To investigate the nature of the interaction between H and Ar and the interaction between Ar and F, the quantum theory of “atoms in molecules” was carried out. The Laplacian (?²ρ_b) values of H? Ar suggest that the covalent interaction plays a key role in the H‐Ar interaction. For Ar? F, the results indicate that the Ar‐F interaction has a dominant noncovalent character. Moreover, the results obtained from the ratio of the kinetic‐energy density (G_b) and the potential‐energy density (V_b) (?G_b/V_b) and the total energy density (H_b) are in good agreement with that of ?²ρ_b values. In addition, the results of natural bond orbital charge and electron density difference between the HArF and BNNTs show that less electrons transfer away from the HArF to BNNTs with the gradual increase in the diameters of the BNNTs. © 2014 Wiley Periodicals, Inc.     

Dioxomolybdenum(VI) complex covalently attached to amino‐modified graphene oxide: heterogeneous catalyst for the epoxidation of alkenes

Transition metal salen complex MoO₂–salen was successfully tethered onto amino‐functionalized graphene oxide (designated as MoO₂–salen–GO), which was tested in the epoxidation of various alkenes using tert‐butylhydroperoxide or H₂O₂ as oxidant. Characterization results showed that dioxomolybdenum(VI) complex was successfully grafted onto the amino‐functionalized graphene oxide and the structure of the graphene oxide was well preserved after several stepwise synthesis procedures. Catalytic tests showed that heterogeneous catalyst MoO₂–salen–GO was more active than its homogeneous analogue MoO₂–salen in the epoxidation of cyclooctene due to site isolation. In addition, the MoO₂–salen–GO catalyst could be reused three times without significant loss of activity. Copyright © 2014 John Wiley & Sons, Ltd.     

中、高能电子被SO2分子散射的微分截面、动量转移截面及弹性积分截面

在考虑分子内成键原子间的电子云重叠效应的基础上, 提出了一种能够准确计算“中、高能电子-分子”散射的微分截面、动量转移截面及弹性积分截面的修正势方法. 利用可加性规则、使用Hartree-Fock波函数并采用被这一方法修正过的复光学势, 在100—1000eV内对电子被SO₂分子散射的微分截面、动量转移截面及弹性积分截面进行了计算, 并将计算结果与实验及其他理论结果进行比较. 结果表明, 利用这一修正过的复光学势及可加性规则获得的微分截面比利用未修正的复光学势及可加性规则得到的结果准 关键词： 可加性规则 微分截面 动量转移截面 电子散射     

MnBi磁性多层膜磁光科尔效应的数值模拟

基于各向异性的平面电磁波传输理论和4×4矩阵法，计算了MnBi，Mn_0.53Bi_0.47，Mn_0.52Bi_0.44Sb_0.04磁性多层膜系列的磁光科尔旋转角、椭圆率随波长、入射角、磁性层厚度变化曲线.计算结果表明，模拟的科尔旋转角、椭圆率随波长变化规律与实验结果吻合很好；在一定波长的垂直入射下，模拟的科尔旋转角、椭圆率随磁性层厚度变化曲线出现科尔谱极大；在磁性层厚度一定的情况下，当入射光以某一角度 关键词： 4×4矩阵法 磁性多层膜 磁光科尔谱 介电张量