Nucleon Compton Scattering in the Perturbative Limit

The paper presents results of perturbative calculations for nucleon Compton scattering. The results are given for the real incoming photon and for the virtual incoming photon.     

实二次函数域基本单位的范

作为Ｈ．Ｆ．Ｔｒｏｔｔｅｒ［３］中一个结果的模拟，本文给出实二次函数域Ｋ中基本单位ε的范为Ｎ（ε）＝ｇ的一些充分必要条件，其中ｇ为Ｋ的常数域Ｆｑ的非零乘法群Ｆｑ＾＊的生成元（２├ｑ）。利用图论的语言，本文还给出了Ｎ（ε）＝ｇ的一些充分条件，这些条件对于数域也同样地适用，从而推广了Ｔｒｏｔｔｅｒ［３］和前人工作中关于充分条件的结果。     

聚丙烯微孔膜的等离子体接枝聚合改性

利用拉伸时的晶型转变致孔特性,从β晶相聚丙烯经单向或双向拉伸制得了新型聚丙烯微孔膜、用等离子体接枝聚合技术接上了亲水性聚合物如聚丙烯酸、聚丙烯腈等。研究了等离子体处理时间、单体性质对得到的亲水膜的亲水性、离子/溶质渗透性的影响。发现接枝聚丙烯酸的双向拉伸膜对Na~+、Mg~(++),尿素有较大的渗透性,并具有优良的形状稳定性。     

Intramolecular motion and isotope effects in muonium‐substituted chloroalkyl radicals

Muon irradiation of pure liquid 3‐chloropropene, CH₂=CH-CH₂Cl, yields a primary radical, \dot\mboxCH₂-CHMu-CH₂Cl, and a secondary radical, MuCH₂-\rm\dot\mboxCH-CH₂Cl. 2‐methyl‐3‐chloropropene yields only the tertiary radical, MuCH₂-\rm\dot\mboxC(CH₃)-CH₂Cl. These three chloroalkyl radicals have been characterized by μSR and μLCR, and the hyperfine coupling constants (hfcs) have been determined over a range of temperatures, either in the pure liquid precursor or in concentrated solution. The temperature variation of the hfcs has been analyzed to obtain estimates of the barrier to internal rotation about the C_\alpha-C_\beta axis for various alkyl groups, and also their minimum energy conformations, i.e. their orientations with respect to the axis of the 2p_z orbital of the unpaired electron. The tertiary radical is particularly interesting because all three methyl‐like groups, -CH₃,-CH₂Cl and -CH₂Mu, are represented. The results can be compared to electron spin resonance data for analogous radicals, to provide information on the effects of Mu substitution for H. This revised version was published online in August 2006 with corrections to the Cover Date.     

The layered compound poly[μ2‐4,4′‐bipyridyl‐di‐μ2‐chlorido‐mercury(II)]

The title compound, [HgCl₂(C₁₀H₈N₂)]_n, features two‐dimensional [HgCl₂(4,4′‐bipy)]_n neutral networks (4,4′‐bipy is 4,4′‐bipyridine), based on an octahedral Hg atom coordinated by four μ₂‐Cl atoms and two μ₂‐4,4′‐bipy ligands in trans positions, yielding a HgCl₄N₂ octahedron. The structure has mmm symmetry about the Hg atoms, with most of the atoms on at least one mirror plane, but the unsubstituted C atoms of the 4,4′‐bipy rings are disordered across a mirror plane. Photoluminescent investigations reveal that the title compound displays a strong emission in the green region, which probably originates from a ligand‐to‐ligand charge‐transfer transition.     

Measurement of small-signal and large-signal responses of packaged laser modules at high temperature

In this paper, the pulsed injection method is extended to measure the chip temperature of various packaged laser modules, such as the DFB laser modules, the FP laser modules, and the EML laser modules. An optimal injection condition is obtained by investigating the dependence of the lasing wavelength on the width and period of the injection pulse in a relatively wide temperature range. The small-signal frequency responses and large-signal performances of packaged laser modules at different chip temperature are measured. The adiabatic small-signal modulation characteristics of packaged LD are first extracted. In the large-signal measurement, the effects of chip temperature, bias current and driving signal on the performances of the laser modules are discussed. It has been found that the large-signal performances of the EML modules depend on the different red-shift speeds of the DFB and EAM sections as chip temperature varying, and the optimal characteristics may be achieved at higher temperature.