利用双相光栅的激光束相干合成

本文介绍一种采用纯双相光栅进行激光束相干相加的方法。用一光栅能把单一光束高效率地分离成N个相等级次激光束,亦能以相同效率把N个相等级次的激光束转换成单一光束。实验证明,它能以75％的总转换效率将七束激光转换成一个单束激光。本文还描述一种实验装置,将两束氦-氖激光与三束氦-氖激光(波长为3.39μm)的功率合成,其效率可高达83％。     

达草灭对莱茵衣藻(Chlamydomonas reinhardtii) 品系遗传后效应的研究

通过将莱菌衣藻（Chlamydomonas reinhardtii）6种达草灭抗性突变株分别与野生型株、丧失合成叶绿素b能力的cbnI-43等基因突变株和精氨酸依赖型突变株杂交对其后代进行四分析与随机分析，发现在Nfr-4-Nfr-7突变株中达草灭抗性状只有单一核基因遗传的性质，而在Nfr-1、Nfr-3～Nfr-7抗性株的抗性性状都是由同一个nfr-1基因（norflurazon resisanse）的突变所决定的，而Nfr-4抗性株的抗性性状是由另一滚突变等位基因nfr-2所决定的。在Nfr-1和Nfr-3抗性株中除了nfr-1基因的突变还有nfr-3基因突变的参与。     

Critical Point Theorems and Applications to Differential Equations

This paper contains a generalization of the well-known Palais-Smale and Cerami compactness conditions. The compactness condition introduced is used to prove some general existence theorems for critical points. Some applications are given to differential equations.     

Remarks on the Regularity to 3-D Ideal Magnetohydrodynamic Equations

In this paper we are interested in the sufficient conditions which guarantee the regularityof solutions of 3-D ideal magnetohydrodynamic equations in the arbitrary time interval [0,T].Fivesufficient conditions are given.Our results are motivated by two main ideas:one is to control theaccumulation of vorticity alone;the other is to generalize the corresponding geometric conditions of3-D Euler equations to 3-D ideal magnetohydrodynamic equations.     

浅水中污染物扩散的自适应有限元分析法

介绍浅水中污染物扩散分析中的有限元法.分析包括两个部分:1)流场速度、水面高度的计算;2)根据扩散模型计算污染物浓度场.联合使用了自适应网格技术以期提高解的精度,同时减少计算时间和计算机内存的消耗.通过几个有已知解的实例验证了有限元公式和计算机程序.最后,使用这种联合方法分析泰国Chao Phraya河附近海湾中的污染物扩散.     

EFFICIENT SIXTH ORDER P-STABLE METHODS WITH MINIMAL LOCAL TRUNCATION ERROR FOR y"=f(x,y)

1. IntroductionWe consider a class of direct hybrid methods proposed in [11 for solving the second orderinitial value problemy" = f(t,y), y(0),y'(0) given (1.1)The basic method has the formandHere t. = nh and we define t.l.. = t. I aih, i = 1, 2 and n=0,1…     

Acetylene weak bands at 2.5 μm from intracavity Cr:ZnSe laser absorption observed with time-resolved Fourier transform spectroscopy

The spectral dynamics of a mid-infrared multimode Cr(2+):ZnSe laser located in a vacuum sealed chamber containing acetylene at low pressure is analyzed by a stepping-mode high-resolution time-resolved Fourier transform interferometer. Doppler-limited absorption spectra of C(2)H(2) in natural isotopic abundance are recorded around 4000 cm(-1) with kilometric absorption path lengths and sensitivities better than 3 10(-8) cm(-1). Two cold bands are newly identified and assigned to the ν(1)+ν(4) (1) and ν(3)+ν(5) (1) transitions of (12)C(13)CH(2). The ν(1)+ν(5) (1) band of (12)C(2)HD and fourteen (12)C(2)H(2) bands are observed, among which for the first time ν(2)+2ν(4) (2)+ν(5) (-1).     

2-碘-N-甲基苯磺酰胺的合成新方法和分子结构

选用新方法合成了2-碘—N-甲基苯磺酰胺，通过^1H NMR,^13C NMR,^13C DEPT NMR(Distortionless Enhancement by Polarization Transfer NMR)和MS确证的其结构。     

15C的中子晕结构研究

实验测量了83A MeV ^14,15C的核反应总截面(σ_R)及¹⁵C产生^14,15C和¹⁴C产生¹³C的动量分布(P_//). 分析得到了¹⁵C产生¹⁴C和¹³C的动量分布半高宽(FWHM)分别为71±9MeV/c和223±28MeV/c, 而¹⁴C产生¹³C的FWHM为195±21MeV/c. 从¹⁵C和¹⁴C产生¹³C的FWHM与Goldhaber模型的预言基本一致. 而¹⁵C产生¹⁴C的FWHM却要比该模型计算小得多. 同时观测到¹⁵C的σ_R比相邻核有反常增加. 在Glauber模型框架中, 对实验测得的P_//和σ_R进行了探讨. P_//和σ_R的分析结果同时显示¹⁵C的最后一个中主要处于s_1/2态, 具有中子晕结构.     

脉冲星射电光度的估计及其演化规律的研究

本文从极冠模型出发导出辐射束的强度分布和新的光度公式.新的光度公式无需对磁倾角和视线扫过辐射束的部位作出假定,采用新的射电光度值来研究光度的演化规律,发现在周期和周期变率的整个取值范围内射电光度可以用关系式L∝(B/P²)^1.1和L∝Q’^-1.4来描写.这和近几年流行的光度规律不同.