CLONING, EXPRESSION AND CHARACTERIZATION OF Pro3 GENE OF YEAST Saccharomyces cerevisiae

The proline biosynthetic pathway and Pro genes in Saccharomyces cerevisiae have just begun to be studied recently. In our laboratory, Pro2 gene of S. cerevisiae had been cloned in yeast. As described in this paper, yeast Pro3 gene was also cloned, which can complement yeast Pro3 mutants, and be expressed efficiently in E. coli. The high activities of this gene product, L-pyrroline-5-carboxylate (P5C) reductase, can be detected in both organisms. The activity of the Pro3 gene product in multiple copy plasmids is not higher than that of single copy genes in chromosomes in both yeast and E. coll. The preliminary characterization of the gene is also reported.     

ALTERATION IN CHROMATIN CONFORMATION OF PROLIFERATING AND DIFFERENTIATING ENZYME GENES IN NORMAL MOUSE LIVER AND ASCITES HEPATOMA CELLS AND ITS RELATION TO THE GENE EXPRESSION OF ENZYMES

Nuclei from the normal mouse liver were partially digested with micrococcal nuclease, followed by DNA extraction, agarose gel clectrophoresis and dot blot hybridization with ~(32)P-labeled cDNA probes of CPS_1 and ACT complex, It was clearly shown that the CPS_1 genes were distributed on the monomer, dimer. and trimer of nucleosomes, while the genes coding for ACT complex were distributed on the condensed oligonucleosomes. An opposite manner of distribution of CPS_1 and ACT complex genes was, however, noted in the case of ascites hepatoma cells, in which the specific activity of ACT was 13 times higher than that in the normal liver, while that of CPS_1 was remarkably reduced. Similar patterns of change in mRNA level of CPS_1 and ACT complex were observed in the normal mouse liver and ascites hepatoma cells, indicating a close relationship between chromatin structure and gene expression of these enzymes.     

EFFECTS OF SOURCE PROPERTIES ON CUTOFF FREQUENCY f_(max)

The cutoff frequency f_(max) of radiation from earthquakes is one of the important parameters for studying the source process. By theoretical analysis and numerical experiments on acceleration Fourier spectrum it is suggested that f_(max) mainly depends on the lower values of slip rise time. This result can be used to explain the observational fact that the greater the earthquake magnitude, the smaller the value of f_(max).     

Nd^3＋：YAlO3晶体折射率温度系数的表示式

建立了Nd~(3+):YAlO_3(Nd:YAP)晶体折射率温度系数的表示式,该式得到的结果与测量值间具有较好的一致性。利用这个式子可以计算0.5398μm～1.0795μm波长范围311K～455K温度范围内Nd:YAP晶体的折射率温度系数。     

Y分岔波导热光控制工作机构

对Y分岔K~+离子交换沟道波导热光控制作用的工作机构进行了理论分析。计算结果表明,只有在Ti薄膜热子下面的区域形成了独立的热光波导,才可能解释实验测得的高消光比值。在器件的制作过程中采用了特殊的SiO_2抬离工艺,     

光纤中稳态受激喇曼散射弧波研究

本文结出了描述光纤中受激喇曼散射过程的方程,通过对这些方程的讨论,得到了在稳态受激喇曼散射过程中可以存在弧波解的结论.这一理论可用于超短脉冲的产生.     

线性三原子分子转动-振动能谱的李群处理方法

本文利用李代数方法与二次量子化理论计算了线性三原子分子的转动-振动能谱.结果表明,如果将分子的转动与振动均看作是谐振子,则可以导致这种分子的转动-振动能谱公式.     

辐射场的压缩的混沌态——Ⅰ. 特征函数和压缩性质

本文用Wigner特征函数方法将压缩的概念推广到一般量子态;详细讨论了一类新的光场状态——压缩的混沌态的量子统计性质,并提出辐射场与其共轭场的光子配组的概念作为其压缩性质的物理解释.     

用互补向量修正阈值的光电混合联想存储器模型

本文提出了一种在联想存储中评价向量间相似程度的新判据.并完成了一种采用互补向量修正阈值的光电混合联想存储器模型的实验研究,该模型可以控制读出向量的精度,能够消除向量的误读.     

反射式全息图的衍射光谱

实验表明,反射全息图的衍射光谱呈现出明显的非对称性,并伴随着一系列次峰的出现。本文报道了多种情况下的实验结果,同时对光谱的特性进行了分析。