The Structures and Stability of HNOS Isomers

Potential energy surface of HNOS system is investigated by means of MP2 method with 6-311 G(d,p) basis set.The energy for each minimum and saddle point on the potential energy surface is corrected at the QCISD(T)/6-311 G(3df,2p) level of theory with zero-point vibrational energy included.As a result ,eighteen isomers are theoretically predicted and cis-HNSO is found to be global minimum on the potential energy surface,Wherein,fourteen isomers are considered as kinetically stable species,and should be experimentally observed.Comparisons are made for HNOS system with its analogues,HNO2 and NHS2.The nature of bonding and isomers‘ stability of HNOS system are similar to HNS2.The obvious similarities and discrepancies among HNOS,HNO2 and HNS2 are attributed to the hypervalent capacity of sulfur,oxygen and nitrogen atoms.     

Three Novel Isomers of FCH2CP System

Three new isomers of FCH2CP system, F(H)CCPH (1), F-cCPC-H(H) (2) and F-cCC(H)P-H (3), are predicted by means of B3LYP and CCSD(T) (single-point) methods with 6-311 G(d,p) and 6-311 G(2df,2p) basis sets, respectively. The three calculated isomers can isomerize into thermodynamically the most stable species F-cPC(H)C-H, which has been suggested in previous theoretical studies, with relatively higher reaction barriers. In view of their higher thermodynamic and kinetic stability, we believe that the three species can be detected in future experiments.     

断口定量分析中高度参数的扫描电镜测定

在断口定量分析中根据双目成象原理,运用扫描电镜技术,实现对断口上高度参数的测量,将扫描电镜中获得的立体感觉转变为相应的几何参数,从而可以从断口上获得高度参数的定量数据。同时还分别讨论了进行断口高度参数测量的倾转法和剖面法。     

利用面阵CCD测量小角度的研究

分析了采用面阵CCD器件和自准直原理实现二维小角度测量的原理和方法,设计了采用计算机控制的高速数据采集和处理软件,通过使用Visual C 语言实现的界面,可以实时显示测量数据.实验表明,该面阵CCD双坐标自准直仪量程为±3′,分辨率优于0.1",测量误差优于0.7".     

Quasi-variational principles of single flexible body dynamics and their applications

The reasons for studying single flexible body dynamics are that on one hand, it is the basis of flexible multi-body dynamics. If the theory of the single flexible body dynamics has been deeply studied, the theory of flexible multi-body dynamics will be researched easily. On the other hand, it has its unique and important applications. Quasi-variational principle of non-conservative single flexible body dynamics is established under the cross-link of particle rigid body mechanics and deformable body mechanics. Taking the interceptor as an example, this paper has explained the physical meaning of the quasi-stationary value condition of the quasi-variational principle in non-conservative single flexible body dynamics. Taking the launch of rocket as an example, it has illustrated the features of “one force for two effects” in a single flexible body dynamics. With an example of the extending flexible beam coupled with the spacecraft attitude, it has shown the transition from the single flexible body dynamics to the flexible multi-body dynamics. Finally, a number of related problems are discussed. Supported by the National Natural Science Foundation of China (Grant No. 10272034), the Doctoral Education Foundation (Grant No. 20060217020), and the Natural Science Foundation of Harbin Engineering University (Grant No. HEUF04003)     

Charge doping effect on σ-π conjugated copolymers

The charge-doping effect on the geometric and the electronic structures of organosilicon oligomers nSix(C=C)+y has been studied using density functional theory. Charge-doping can significantly lower the excitation energies. Interchain hole hopping mainly occurs between the π-conjugated units. A doped nSix(C=C)+y oligomer can undergo a structural rearrangement. The simulated UV/vis absorption peak of the rearranged structure is located at higher energy than the non-rearranged one. The hole transfer rate is s...     

近场波动的数值模拟

本文评述了近年来波源（或散射体）及其邻域内波动数值模拟的主要研究结果，着重讨论了人工边界条件这一关键问题的研究进展     

Orlicz空间的LURWC条件

本文给出Ｏｒｌｉｃｚ函数空间关于Ｌｕｘｅｍｂｅｒｇ范数ＬＵＲＷＣ点和ＬＵＲＷＣ性质判定准则。     

MEG反源问题的一种数值方法

1引言所谓MEG(脑磁图)反源问题,就是根据头外电磁场数据确定脑内神经电流源的活动情况.此类反问题在生物医学中有着广泛的应用,其最经典的一个应用即利用脑磁图仪器确定癫痫病人脑部病灶的位置.癫痫是由脑部神经元群阵发性异常放电所致,这些神经元群的体积一般都很小,因而可以被近似看作是偶极子源[1,6].本文即是考虑由此衍生的反     

数字／模拟混合硬件描述语言VHDL—AMS

自１９８７年ＶＨＤＬ成为ＩＥＥＥ标准以来，ＶＨＤＬ已被工业界广泛认可，并取得了巨大的成功。对于模拟及数字／模拟混合系统，尚没有一种ＩＥＥＥ标准的硬件描述语言问世。介绍了一种正在标准化进程中的数字／模拟混合硬件描述语言ＶＨＤＬ－ＡＭＳ，该语言以ＶＨＤＬ’９３为基础，在其中加入了可描述模拟系统的对象，类型和结构。