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781.
MaSu-yan CaiDong-han 《武汉大学学报:自然科学英文版》2004,9(3):278-282
The existence and uniqueness of the modified Uzawa-Lucas growth model which incorporates unskilled labor as a distinct factor from human capital are given and the dynamics of the model is presented. Furthermore, the varieties of the time allocation to the physical and human capital production along the optimal path and the affections of fertility and the natural growth rate of human capital on economic growth are discussed. 相似文献
782.
YangChun-hua ZhuGuo-qiang 《武汉大学学报:自然科学英文版》2004,9(3):313-318
In the composed system of a target and rough surface, the electromagnetic scattering mechanism, especially the multipath scattering, is investigated. Using physical optics double bouncing algorithm, the multipath scattering model of the system has been established. Simulated by a wideband radar signal and based on fractal rough surface, the artificial echo of the target has been obtained in virtue of the established multipath scattering model. By simulating to image the target in one dimension using the artificial echo, two kinds of range profiles are attained. It is found that one is from the target and the other is from the multipath scattering effect. 相似文献
783.
JIANGWei-jin XUYu-sheng 《武汉大学学报:自然科学英文版》2004,9(5):735-739
We put forward a chaotic estimating model, by using the parameter of the chaotic system, sensitivity of the parameter to inching and control the disturbance of the system. and estimated the parameter of the model by using the best update option. In the end. we forecast the intending series value in its mutua[[y space. The examp[e shows that it can increase the precision in the estimated process by selecting the best mode[ steps. It not only conquer the abuse of using detention inlay technology alone, but also decrease blindness of using forecast error to decide the input model directly, and the result of it is better than the method of statistics and other series means, 相似文献
784.
SUYun-Xue ZHUYue-fei 《武汉大学学报:自然科学英文版》2004,9(5):745-748
This paper describes the research results and development of fair off-line e~eash systems so far, and points out that in these systems, the bank can compute the doublespender‘s account secret key, thus the bank can impersonate the double-spender to withdraw from the double-spender‘s account. This article utilizes anonymity control and group signature to address this shortcoming. 相似文献
785.
GAOFu-xiang YAOYu LIUQiong LIANGLiang YAOLan ZHAOZhi-bin 《武汉大学学报:自然科学英文版》2004,9(5):760-764
In this paper, a mechanism of bi directional proxy is proposed, which supports authentication based on identity, and endue different users with different network access permissions. This technology is purposed with a new idea towards the implementation of network security, which has a promising future in applications. 相似文献
786.
787.
XuRen-zuo MaRuo-feng LiuLi-na XiongZhong-wei 《武汉大学学报:自然科学英文版》2004,9(1):18-22
The general human factors analysis analyzes human functions, effects and influence in a system. But in a narrow sense, it analyzes human influence upon the reliability of a system, it includes traditional human reliability analysis,human error analysis, man-machine interface analysis, human character analysis, and others. A software development project in software engineering is successful or not to be completely determined by human factors. In this paper, we discuss the human factors intensions, declare the importance of human factors analysis for software engineering by listed some instances. At last, we probe preliminarily into the mentality that a practitioner in software engineering should possess. 相似文献
788.
LIYang WANGLiduo CHANGChun DUANLian QIUYong 《科学通报(英文版)》2004,49(13):1328-1331
The transparent ITO/Ag/ITO multi-layers are developed as anodes on flexible PET (poly(ethylene terephthalate)) substrates. The influence of these anodes on FOLED (Flexible Organic Light-emitting Diodes) is investigated. From the results of research, it can be seen that the multi-layer anode has optimum characteristics, whose sheetresistance is 11 Ω and optical transmittance is about 80%,when the thickness of Ag sandwiched by two ITO layers is in the range of 14--18 nm. It is demonstrated that the OLED devices with multi-layer anodes give better luminescence and higher efficiency compared with those with single ITO anodes. 相似文献
789.
YUXuping ZHUJunli YAOXunping HEShicheng HUANGHaining CHENWeiliang LIDebao 《科学通报(英文版)》2004,49(13):1370-1375
To understand the antagonistic mechanism of the broad spectrum antagonistic Enterobacter cloacae B8,Tn5 transposon-mediated mutagenesis is performed using suicide plasmid pZJ25. Two mutant strains that lost antagonistic character are isolated. Tagging with kanr gene on Tn5,an antagonistic related DNA fragment, the F fragment, right of the Tn5 insertion site is cloned in a plasmid named pTLF,from one of the mutant strains B8F. The 733 bp F fragment is then sequenced after subcloning. Genomic DNA of the original B8 strain is isolated, digested with Pst I and ligated to Pst I cassette. DNA fragments left and right of the F fragment are amplified from the Pst I cassette library using cassette primer and specific primers designed according to known sequence. 1106 bp sequence left of the F fragment and 664bp sequence right of the F fragment are finally obtained. Bioinformatics analysis shows that the contig assembled from the sequences of the cloned antagonistic related DNA fragments of B8 encodes three ORFs and is homogeneous to admM,admN and admO genes of Pantoea agglomerans andrimid biosynthetic gene cluster (AY192157). The ORF, named anrF gene which encodes a polyketide synthase, knocked out by Tn5 insertion, is a homology of admM and the insertion site of Tn5 is at 214 bp upstream of the stop codon. It is concluded that the anrF gene is a gene related to the antagonistic activity of E. cloacae B8, and speculated that the antagonistic substance produced by B8 is an andrimid. 相似文献
790.