四原子分子的转动-振动能级的李代数处理-Ⅰ线性X_2Y_2型分子

本大利用李代数方法与二次量子化理论计算了四原子分子的转动—振动能级.结果表明,如果将分子的转动与振动均看作是谐振子,则可以导出线性X_2V_2型分子的转动—振动能级公式。     

三组元超导复合线绕磁体的快速励磁特性

采用强迫励磁和在额定电流下突然合闸两种励磁方式,研究了国产Nb-Ti-Cu-Cu-Ni三组元超导复合线绕磁体的快速励磁特性.得到了在临界电流不发生明显退化时的最大励磁速率.提出了改善材料稳定性的建议.     

“直接线性变换”用于爆破过程高速立体摄影解析的可行性和精度问题

高速摄影作为研究岩土爆破过程的观测手段已有数十年的应用历史,观测内容主要是爆破介质的破裂和运动。研究爆破介质的运动大多是研究其整体的移动—岩(土)体表面的鼓包运动或破碎介质群体的抛掷。     

用“冲击电流计测高电阻”实验的改进

本文用电子线路控制器代替复杂的手工操作，使实验数据可靠，误差减小．     

多把钥匙问题的一般情形

在计数问题中常常遇到多把钥匙开锁问题.主要解决下列三个问题:(1)计算至少需要几把锁;(2)每人至少要掌握几把钥匙;(3)如何将钥匙进行适当的分配.本文引进了内集族及与之相应的外集族、临界集族的概念,把多把钥匙开锁问题推广到一般情形,并在一般情形时解决了前述三个问题.本文还对集族中两两互不包含的集合的基数作出了估计.     

初中化学“铁和其他金属”的教学法

根据教学大纲及课本体会到本章的教学目的有下列几点: 1.使学生初步认识钢铁和几种重要有色金属的性质、用途,以及它们在国民经济中所起的作用。 2.介绍从矿石中冶炼铸铁的基本原理,与主要的生产过程,给学生以化学冶金初步的基本知识。 3.使学生明了“合金”的概念,并知道几种最重要的合金的组成性质和用途。 4.通过我国和苏联钢铁工业发展状况,和它在经济建设和国防建设上所起的作用,说明我国在社会主义工业化首先发展重工业的重大意义。     

Growth of Semi-Insulating GaN by Using Two-Step AIN Buffer Layer

Semi-insulating GaN is grown by using a two-step A1N buffer layer by metalorganic chemical vapour deposition. The sheet resistance of as-grown semi-insulating GaN is dramatically increased to 10^13 Ω/sq by using two-step A1N buffer instead of the traditional low-temperature GaN buffer. The high sheet resistance of as-grown GaN over 10^13 Ω/sq is due to inserting an insulating buffer layer （two-step A1N buffer） between the high-temperature GaN layer and a sapphire substrate which blocks diffusion of oxygen and overcomes the weakness of generating high density carrier near interface of GaN and sapphire when a low-temperature GaN buffer is used. The result suggests that the high conductive feature of unintentionally doped GaN is mainly contributed from the highly conductive channel near interface between GaN and the sapphire substrate, which is indirectly manifested by room-temperature photoluminescence excited by an incident laser beam radiating on growth surface and on the substrate. The functions of the two-step A1N buffer layer in reducing screw dislocation and improving crystal quality of GaN are also discussed.     

Semiclassical calculation of Rydberg He2^＋ molecular of recurrence spectra ion in a magnetic field

Making use of the molecular closed-orbit theory and a new model potential for the Rydberg molecule, we have calculated the recurrence spectra of He^2＋ molecular ion in a magnetic field for different quantum defects. The Fourier transform spectra of He^2＋ molecular ion may be used to perform a direct comparison between peaks in the spectra and the scaled action values of closed orbits of the excited electron in external fields. We find that the spectral modulations can be analysed in terms of the scattering of the excited electron on the molecular core. Unlike the case of the Rydberg atom where the elastic scattering is predominant, modulations produced by inelastic scattering are also vital to the photoabsorption spectrum of the Rydberg molecule. Our results are in good agreement with the quantum results, which suggests that our method is correct.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

共价抑制剂的研究进展

共价抑制剂因其具有的优异的药代动力学特征,在近期的药物研发领域中起到了关键作用.共价抑制剂是一类有机小分子,能与特定的靶蛋白相互作用并形成共价键,导致蛋白质构象的改变,从而抑制蛋白质的活性.除了部分例外,通过共价抑制剂进行的蛋白质修饰通常是不可逆的.重点讨论通过迈克尔加成、亲核取代以及二硫键与蛋白质相互作用的商业共价抑制剂.有关于共价抑制剂中各种类型弹头的讨论,可以激发未来合理药物设计的灵感.