Radiation-induced fermion resonance

The Dirac equation is solved for two novel terms which describe the interaction energy between the half-integral spin of a fermion and the classical, circularly polarized, electromagnetic field. A simple experiment is suggested to test the new terms and the existence of radiation-induced fermion resonance.     

A characterization of the \Sigma_1-definable functions of KP\omega + (uniform\; AC)

The subject of this paper is a characterization of the -definable set functions of Kripke-Platek set theory with infinity and a uniform version of axiom of choice: . This class of functions is shown to coincide with the collection of set functionals of type 1 primitive recursive in a given choice functional and . This goal is achieved by a G?del Dialectica-style functional interpretation of and a computability proof for the involved functionals. Received October 9, 1996     

选择性远程DEPT~(13)C NMR新技术用于新阔叶千里光碱氮氧化合物的结构测定和谱峰归属研究

从湖北蟹甲草根茎中分得一个新的生物碱,选择性远程DEPT~(13)C NMR新技术用于识别NMR信号归属和连接被季碳及杂原子分割的质子自旋系统,确定其结构为新阔叶千里光碱的氮氧化物,如(1)所示。     

基团共轭效应研究Ⅱ：^13C核磁共振的化学位移与取代基的共轭效应强度

引言在定量和定性研究有机化合物的结构与性质的关系中,最广泛使用的是Hammett等所提出的σ_m、σ_p等取代基常数以及基团的诱导(场)效应和共轭效应常数。在建立基团的共轭效应常数方面,人们做了大量的工作,但多数工作是基于对基团的Hammett常数σ的人为分解上,建立的模型和分解方式(系数因子)不同,则得到不同的结果。另一方面纯理论计算工作大多引入较多参数,使计算复杂和使用不便。作者曾在建立表征诱导效应大小的     

The Modified Group Expansions for Construction of Solutions to the BBGKY Hierarchy

A solution to the BBGKY hierarchy for nonequilibrium distribution functions is obtained within modified boundary conditions. The boundary conditions take into account explicitly both the nonequilibrium one-particle distribution function as well as local conservation laws. As a result, modified group expansions are proposed. On the basis of these expansions, a generalized kinetic equation for hard spheres and a generalized Bogolubov–Lenard–Balescu kinetic equation for a dense electron gas are derived within the polarization approximation.     

反光板(合作目标)反射率测量仪

本文介绍了反光板（合作目标）反射率测量仪的研制。仪器采用对称双光路比较测量法，给定两束相等光通量的光束，分别作为参考光束和测试光束，并用分束器实现原光路取样，从而解决了合作目标反光板入射光线与反射光线重合不能用常规测试方法来检测的难题。由于采用对称双光路的方法，入射光通量是相对恒定的，不受外界因素影响，从而使反射率测量仪达到精度高、重复性好和环境要求低的设计要求。     

Topological order in the phase diagram for high-temperature superconductors with point defects

Applying a Lindemann like criterion obtained previously by Kierfeld et al. [J. Kierfeld, T. Nattermann, T. Hwa, Phys. Rev. B 55 (1997) 626], we estimate the magnetic field and temperature for a high-T_c superconductor, at which a topologically ordered vortex glass phase becomes unstable with respect to a disorder-induced formation of dislocations. The employed criterion is shown to be equivalent to a conventional phenomenological Lindemann criterion including the values for the numerical factors, i.e., for the Lindemann number. The positional correlation length of the topologically ordered vortex glass is calculated.     

Thermal Analysis of the Conformational Disorder in SCLC Polymers with Rigid Backbone Glass transition studies

Bis [(ω-(4′-cyanobiphenyl)-4-yl)oxy-n-alkyl]norborn-5-ene-2,3-dicarboxylate was polymerised via ring opening metathesis polymerisation (ROMP). Two disubstituted polynorbornene derivatives both of cis configuration with different length of the side-chain were studied. Differential scanning calorimetry (DSC) was used to study the effect of thermal history on the assignment of the glass transition event associated with the biaxial orientation of a smectic phase. Glass transition temperatures, the change of isobaric specific heats at T_g and the enthalpies of isotropisation were calculated. The DSC traces only show the classic step-wise change in T_g in some cases, giving the evidence that the amorphous domains are constrained and highly restricted in movement due to the morphology developed as a result of the biaxial stretching. Based on the literature data of mono- and disubstituted polynorbornene derivatives and our calorimetric experiments, the shape of T_g dependence on number of (CH₂) units is interpreted. The origin of this shape is discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

分布耦合系数对线性啁啾光栅色散的影响

本文从光栅反向耦合波方程出发,经相位共轭变换用Runge-Kuta-Gil方法对其数值求解。针对线性啁啾光栅耦合系数变化服从不同的分布,分析了各种分布对光栅反射谱特性和色散特性的影响。