Methyl hydrogen peroxide dimer: A structural study

Methyl hydrogen peroxide (MHP) exhibits a tendency to form a stable dimer by hydrogen-bonding. Ab initio theoretical investigations on methyl hydrogen peroxide dimer (MHPD) carried out herein lead to several energetically stable structures that have a direct bearing on the reactivity of the monomer in terms of its molecular electrostatic potential (MESP). To gauge the role played by the electron-correlation in lending stability to MHP and its dimer, we employ the density functional theory (DFT) (as implemented by B3LYP-functional), and subsequently second order Møller-Plesset (MP2) perturbation theory, using the basis sets 6-31G(d, p) and 6-311++G(2d, 2p). Simulated infra-red vibrational spectra lead to spectral intensity redistribution upon dimerization. Energetically the lowest MHPD is endowed with inversion symmetry and has two hydrogen bonds, while three other structures emerge: one energetically very close with two H-bonds, and the two others, with three H-bonds each, yet higher by about 2 kcal mol⁻¹.     

Pd-Y微团簇的结构与性质研究

在相对论有效原子实势近似下，用密度泛函理论方法，对Pd_n(n=2,3,4)，Y_n（n=2,3,4）,Pd_nY(n=1,2,3,4)，PdY_n(n=2,3,4)，Pd₂ Y_n(n=2,3,4)团簇的各种可能的几何构型进行全优化计算,得到它们的基态结构和 光谱性质.结果表明，由于 Jahn-Teller效应， Pd₄和Y₄的基态结 构为C_s构型，P d₃和Y₃为C_2v 构型；混合微团簇Pd₃Y，Pd ₄Y，PdY₃，PdY₄ 和 Pd₂Y₄基态为C_s构型.最后计算了团簇的能级分布和最 高占据轨道与最低空轨道之间的能级间隙,分析了团簇的化学活性. 关键词： Pd-Y团簇 有效原子实势 密度泛函     

Ar＋TlF体系的转动非弹性散射

本文用一种新的方法求解A+BC体系的转动非弹性散射问题,即在径向耦合方程的势能耦合项中只取对角项,并用Morse势拟合Lennard-Jones势,从而可得去耦合径向方程的两个解集。渐近分析表明,此两个解集分别相应于入射波和出射波。将总波函数按总角动量的本征函数展开,展开系数为常数乘以上述得到的径向函数。再将总波函数代入Schrdinger方程,则可得到散射矩阵。计算结果表明,本法比IOS法更接近CC法,但计算量比后者少得多,且方法严谨。     

Recording of PIV images on photothermoplastic plates

In this paper we explore the possibility of utilizing commercially available photothermoplastic plates as recording support in Particle Image Velocimetry (PIV), to allow real time analysis of recorded data. An experimental apparatus has been developed which allows holographic recording and reconstruction of simulated PIV images. We show that double exposed photothermoplastic plates can successfully be analysed provided that a suitable recording/reconstruction scheme is used.     

实验评估全息凹面光栅平场摄谱仪

阐述ＳＰＤ－Ｉ型全息凹面衍射光栅平场摄谱仪的基本工作原理和仪器结构，详细报导了该仪器的适用波长范围、平直谱面长度、倒数线色散率和光谱带宽等主要技术性能的光学测试方法和实验结果。测量结果表明在设计波长范围（４００至８００ｍｍ）内像差校正良好，获得的平直谱面可与光敏面长度为一英寸（２３．５ｃｍ）的多通道探测器相配；仪器的色散相当均匀（约１７ｎｍ／ｍｍ），在５７９．９６ｎｍ波长处测得的光谱带宽为１ｎｍ，能满足一般光学多通道分析仪的要求。     

流体的塔阱状态方程及其对迁移性质的推算

流体的塔阱状态方程及其对迁移性质的推算曾向东，严家（哈尔滨工业大学能源科学与工程学院哈尔滨１５０００６）牛文科，韩立中（哈尔滨船舶锅炉涡轮机研究所哈尔滨）关键词势能模型，配分函数，状态方程，平衡性质，迁移性质１流体的塔阱状态方程Ｐｒｉｇｏｇｉｎｅ认为...     

一种不含自由参数的正电子吸收势

在准自由电子气模型的基础上得到一种不含自由参数的正电子吸收势，把它作为光学势的虚部，计算了能量在最小非弹性阀值到１００ｅＶ范围内正电子被Ｈｅ、Ｎｅ、Ａｒ原子散射的总截面和能量为２００ｅＶ和３００ｅＶ时的散射微分截面，计算结果与实验进行了比较。     

AC transport current loss of assembled conductor of HTS tapes

We study experimentally and theoretically the AC transport current loss characteristics of a tape in multiple tapes assembled in single layer and subject to external field produced by transport currents of adjacent tapes. We measured the AC transport current losses of a Bi2223 silver-sheathed tape in a single layer arrangement of three tapes using our newly developed potential leads arrangement to avoid spurious loss components caused by the magnetization in the adjacent tapes. In the paper, the influence of the external AC field produced by adjacent tapes on the loss characteristics is studied based on the experimental results and theoretical analysis.     

Holographic Storage Parametric Optimization of the Crystal LiNbO3∶Fe Based on One-center Model

Based on one-center model, the effects of the doping amount and the degrees of reduction and oxidation on the dynamic range M, the response time and the photorefractive sensitivity in the crystal LiNbO3∶Fe are analyzed in detail. The principle of material optimization is discussed. The best crystal thickness (about 1.4～2.6 mm) for the maximum dynamic range M is calculated for the different doping amounts. The results show that the more the doping amount, the lighter the reduction of the crystal should be chosen, and that the heavier the reduction of the crystal, the less effect the doping amount has on the response time. The dynamic range M is in conflict with the response time. Due to the difficulty of processing crystals, the thickness is increased to 5 mm at the cost of decreasing the dynamic range M by 0.3～0.5.