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951.
桥梁结构基于动力特性的损伤诊断方法 总被引:1,自引:1,他引:0
阐述了基于结构动力特性的桥梁损伤诊断基本原理和方法,比较分析了各类损伤诊断方法的特点及适用条件,并指出了桥梁结构基于动力特性的损伤诊断方法和进一步需要研究解决的问题. 相似文献
952.
W. B. Rhoten 《Cellular and molecular life sciences : CMLS》1987,43(4):428-430
Summary Immunocytochemistry was carried out on sections of pancreas from the gopher tortoise,Gopherus polyphemus. Combined immunofluorescent and peroxidase-anti-peroxidase techniques showed unequivocally that some of the cells were immunoreactive for both glucagon and pancreatic polypeptide (PP). Antibodies directed against avian PP, bovine PP, and human PP all have a positive reaction. Co-localization of glucagon and PP in the pancreas of the gopher tortoise indicates that the occurrence of these hormones in the same cells is widespread in higher vertebrates.Acknowledgments. This work was supported in part by grants from the University of Cape Town, the M. Crossley bequest, the N. Atkinson bequest, and Herman and Caporn bequests. The generous gifts of antisera by Dr Chance and the late Dr Kimmel, and the gift of hormones by the Lilly Research Laboratories are gratefully acknowledged. The excellent technical assistance of J. Thompson and J. B. De Haan is also gratefully acknowledged. Please send all correspondence to the USA address. 相似文献
953.
Summary Rabbit liver mitochondrial fraction shows lactate dehydrogenase activity. The enzyme can be released from particles by increasing the pH and the ionic strength of the medium. There is a narrow range of pH (6.8–7.4) and ionic strength (20–50 mM NaCl) in which the solubilization sharply increases. It has been shown that divalent anions (SO
4
2–
) and cations (Mg2+, Ca2+) are highly effective specific solubilizing agents. NADH (1.5 mM) and ATP (1.0 mM) were effective in solubilizing 50% of the enzyme bound, whereas the same concentrations of the analogs NAD+ and ADP had little effect. Cytosolic lactate dehydrogenase bound to the mitochondrial fraction and a saturation of particles by enzyme was observed in all experiments performed. The in vitro binding requires a short period of incubation between the enzyme and particles and the binding is independent of the temperature in the 0–37°C range. Binding was prevented by 0.15 M NaCl. The bound enzyme is approximately 20% less active than the soluble one. The results described give support to the proposal that rabbit liver lactate dehydrogenase has an ambiquitous behavior, like other glycolytic enzymes, which have not a fixed intracellular localization. 相似文献
954.
本文利用A、B构成序列有不同排列方式,模拟出晶体、孪晶、准晶和无序的一维结构。应用紧束缚模型,对各结构的电子态进行计算研究,系统地分析比较了各序列的电子能谱、态密度、局域度以及波函数图象,得出准晶体结构是一种新的结构,其电子态不同于晶体、孪晶及无序体的电子态等结论。 相似文献
955.
ZHENGHongkun CHENHong WANGWen 《科学通报(英文版)》2005,50(11):1126-1130
The origin of new structures and functions is an important process in evolution. In the past decades, we have obtained some preliminary knowledge of the origin and evolution of new genes. However, as the basic unit of genes, the origin and evolution of exons remain unclear. Because young exons retain the footprints of origination, they can be good materials for studying origin and evolution of new exons. In this paper, we report two young exons in a zinc finger protein gene of rodents. Since they are unique sequences in mouse and rat genome and no homologous sequences were found in the orthologous genes of human and pig, the young exons might originate after the divergence of primates and rodents through exonization of intronic sequences. Strong positive selection was detected in the new exons between mouse and rat, suggesting that these exons have undergone significant functional divergence after the separation of the two species. On the other hand, population genetics data of mouse demonstrate that the new exons have been subject to functional constraint, indicating an important function of the new exons in mouse. Functional analyses suggest that these new exons encode a nuclear localization signal peptide, which may mediate new ways of nuclear protein transport. To our knowledge, this is the first example of the origin and evolution of young exons. 相似文献
956.
证明了广义Fitz-Hugh-Nagumo方程组存在惯性分形集,且其分形维度是有限的.获得了这个方程组整体吸引子的一个指数型的紧分形局部化逼近序列,并得到了它的一种分形结构,从而改进并精细了已有文献关于这个方程组吸引子的结果 相似文献
957.
介绍了XView的基本结构及其程序设计环境,着重讨论了XView应用程序界面的汉化技术,该方法主要用于XView在西文状态下的应用程序界面汉化和绘图窗口中. 相似文献
958.
959.
960.
观察了两相钛合金(Ti-4.5Al-5Mo-1.5Cr)在810~940C温度和10~0s~(-1)~l0~(-3)s~(-1)应变速率范围内的高温形变行为。分析了磨擦力和形变热对此合金高温形变的影响,并采用不同的方法计算出特定条件下的塑性变形激活能。最后,利用流变区域化参数α对合金高温不稳定流变行为进行了详细分析,表明此参数应用的可行性。 相似文献