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71.
以满江红鱼腥藻(Aac)提取总DNA为模板,通过PCR技术,扩增得到其谷氨酰胺合成酶基因(glnA)上游区.经酶切得到409bp的片段,并将其连接到pBluescriptⅡks+上测序.将测序结果与Anabaena7120调控序列比较,有982%的同源性.在上游调控中也具有niflike和E.colilike启动子,值得注意的是,调节蛋白VF1的结合位点正好位于niflike启动子上.所克隆的片段不但对蓝藻固氮、泌氨的基因调控研究具有意义,也对表达载体的构建具有实用价值. 相似文献
72.
提出了一种使用非线性循环数列解决堆栈问题的算法,对研究栈的性质和求解栈的输出序列具有一定的实用价值。 相似文献
73.
Genomic organization of EDSV strain AA-2 总被引:1,自引:0,他引:1
Liyu Zeng Qi Jin Jinggang Zhang Maoxiang Li Hong Li Lei Zhu Zhen Yin Yunde Hou 《科学通报(英文版)》1998,43(7):594-594
The genomic organization of egg drop syndrome virus strain AA-2 isolated in China is reported here. The genome was found to be 32 838 bp in length, approximately 2 kb shorter than those of the human subgenus C adenoviruses. Analysis of open reading frames indicated that the genes for major viral structural proteins (55 K, Penton base, pⅦ, pⅩ, pⅥ, Hexon, 100 K, pⅧ and Fiber), as well as EP, DNA polymerase and ⅣaⅡ are present in the expected locations in the genome. EDSV possesses no identifiable E3 and E4 regions and most proteins encoded by E3 and E4 regions of other adenoviruses genome were not presented in EDSV. 相似文献
74.
For double arrays of constants {a
ni, 1≤i≤k
n, n≥1} and NA r.v. 's {X
n, n≥1}, conditions for almost sure convergence of
are given. Both casesk
n ↑ ∞ andk
n=∞ are treated. A Marcinkiewicz-type theorem for i. d. NA sequences is obtained as a special case.
Supported by the National Natural Science Foundation of China
Cheng Riyan: born in 1968, MS student 相似文献
75.
谢惠民 《苏州大学学报(医学版)》1993,9(2):112-118
For unimodal maps on the interval we prove that, if the kneading sequences (KS) are eventually periodic, then their formal languages are regular ones. The finite automata for such languages are constructed. Comparing with the languages generated by periodic KS, it is shown that the languages here are not finite complement languages. 相似文献
76.
The microstructure of a series of high conversion copolymers of methyl acrylate (MA) and N-vinylcarbazole (NVC) was characterized by NMR. 1H- and 13C-NMR spectra were assigned by comparison to the homopolymers and by using heteronuclear shift correlation spectroscopy. MA-centered triad distributions were obtained from the carbonyl carbon. Distributions of NVC sequences were determined from aromatic carbons 1 and 8a, and aromatic proton 1 These experimentally determined sequence distributions were compared to those calculated from reactivity ratios approximated from the copolymer compositions. Agreement was very good for low NVC content copolymers. Three signals were particularly useful in providing rapid assessment of the distribution of NVC units within low NVC content copolymers: proton 1 and carbon 1 of NVC and the carbonyl carbon of MA. © 1992 John Wiley & Sons, Inc. 相似文献
77.
The glass transition temperature of a copolymer depends not only on chemical composition but also on its comonomer sequences. This experimental fact is explained by Barton's and Johnston's equations. Their equations, though complicated, become simple, if a suitable parameter is used to describe the comonomer sequences. It is shown that with these new expressions, their equations can be used to understand glass transition temperatures of two additional types of copolymers, compatible multiblock copolymers and homopolymers with various tacticities treated as steric copolymers.Dedicated to Professor Bernhard Wunderlich on the occasion of his 65th birthdayWe wish to thank the reviewer for his/her kind linguistic improvement of this article. 相似文献
78.
This paper applies discrete wavelet transform (DWT) with various protein substitution models to find functional similarity of proteins with low identity. A new metric, 'S' function, based on the DWT is proposed to measure the pair-wise similarity. We also develop a segmentation technique, combined with DWT, to handle long protein sequences. The results are compared with those using the pair-wise alignment and PSI-BLAST. 相似文献
79.
Jae Ha Kim Young Tae Jeong Seong Ihl Woo 《Journal of polymer science. Part A, Polymer chemistry》1994,32(15):2979-2987
Highly active catalysts for copolymerization have been prepared by the precipitation of MgCl2/ToCl4 complex with or without high surface area silica. Copolymerization of ethylene and 1-butene has been tested by using the prepared catalysts at various concentrations of 1-butene. The catalytic activities are 20–80 kg/g Ti h. The rate of copolymerization is strongly affected by the addition of 1-butene. The decay rate of copolymerization is first order with respect to time. Analyses of copolymers with solvent extraction, DSC, IR, XRD, and NMR were performed. Ethylene reactivity ratio (k11) for TiCl4/MgCl2/THF catalyst is calculated to be about 26 by NMR spectrum. © 1994 John Wiley & Sons, Inc. 相似文献
80.
The conformational properties and elastic behaviors of protein-like single chains in the process of tensile elongation were investigated by means of Monte Carlo method. The sequences of protein-like single chains contain two types of residues: hydrophobic (H) and hydrophilic (P). The average conformations and thermodynamics statistical properties of protein-like single chains with various elongation ratio λ were calculated. It was found that the mean-square end-to-end distance r increases with elongation ratio,λ. The tensor eigenvalues ratio of : decreases with elongation ratio λ for short (HP)x protein-like polymers, however, the ratio of : increases with elongation ratioλ,especially for long (H)x sequence. Average energy per bond increases with elongation ratioλ, especially for(H)x protein-like single chains. Helmholtz free energy per bond also increases with elongation ratioλ. Elastic force (f), energy contribution to force (fU) and entropy contribution to force (fs) for different protein-like single chains were also calculated.These investigations may provide some insights into elastic behaviors of proteins. 相似文献