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151.
强半无爪图的完全圈可扩性   总被引:6,自引:3,他引:3  
证明了连通局部连通的强半无爪图是完全圈可扩的.从而推广了Oberly D,Sumner D,Clark L,Hendry G R T等的相关结果.  相似文献   
152.
本文介绍了以甲基硅油─—液体石蜡为主体消泡组分,辅以多种乳化剂和助剂,在水相中复合而成的消泡剂。讨论了消泡效果,乳液稳定性和制备工艺。  相似文献   
153.
本文论述了高等院校创办高新技术产业的意义、作用和有力条件,并针对一些问题提出了进一步发展校办高新技术产业的五项对策。  相似文献   
154.
本文研究了汞膜电极上硫化汞膜在 Na OH—EDTA—VC 体系中的沉积和溶出行为,试验了富集电位、富集时间、扫描速度,溶液组分与温度的影响。应用本方法对Al(OH)_3和水中的微量硫化物进行测定,检测下限可达0.4ppb。  相似文献   
155.
The interaction of nelin, a cardiac-specific expressed protein of human novel gene nelin, with F-actin was studied by both F-actin cosedimentation in vitro and colocalization assays. The results showed that nelin is a new F-actin binding protein and is colocolized with F-actin in cytoplasm of cells. Three new nelin binding proteins, filamin C subtype, titin N2B subtype and inter-alpha trypsin inhibitor heavy chain precursor (ITIH), were identified from human heart cDNA library using yeast two-hybrid screening. The binding activity of filamin C with nelin was confirmed by coimmunoprecipitation. Filamin C binds to nelin through its C-terminal region. It is indicated that nelin is a cytoskeleton associated protein and acts as a membrane-cytoskeleton associated protein involved in the formation of focal adhesions.  相似文献   
156.
Stromatolitesareusuallyinterpretedastheorgano-sedimentarystructurescausedbythegrowthandmetabo-lismofmicro-organisms,principallycyanobacteriaandprecipitatedmineralgrainstrappedtothestickylay-ers[1—5].Asthesunlightisstrongindaytime,thealgaefila-mentsshowstrongactivityinphotosynthesisandgrowtowardsunlight.Ontheotherhand,asthesunlightisweakatnight,thealgaefilamentsshowinactivityinphotosyn-thesisandgrowhorizontally.Duringthecourseofgrowth,thealgaewillproducesomeglutinoussecretionwhichcancatchsedim…  相似文献   
157.
Stellar occultations--the passing of a relatively nearby body in front of a background star--can be used to probe the atmosphere of the closer body with a spatial resolution of a few kilometres (ref. 1). Such observations can yield the scale height, temperature profile, and other information about the structure of the occulting atmosphere. Occultation data acquired for Pluto's atmosphere in 1988 revealed a nearly isothermal atmosphere above a radius of approximately 1,215 km. Below this level, the data could be interpreted as indicating either an extinction layer or the onset of a large thermal gradient, calling into question the fundamental structure of this atmosphere. Another question is to what extent Pluto's atmosphere might be collapsing as it recedes from the Sun (passing perihelion in 1989 in its 248-year orbital period), owing to the extreme sensitivity of the equilibrium surface pressure to the surface temperature. Here we report observations at a variety of visible and infrared wavelengths of an occultation of a star by Pluto in August 2002. These data reveal evidence for extinction in Pluto's atmosphere and show that it has indeed changed, having expanded rather than collapsed, since 1988.  相似文献   
158.
A real-size experiment on 11 tubes was done to study the performance of centrifugal concrete-filled steel tubes under bending and torsion. This paper first introduces the relevant operating method, equipment, subjects and processes. The factors that affect deformation and stiffness and the break mechanism under different loading were studied. Experimental stress analysis showed that the values of practical critical stress of steel tubes accorded well with the MISES Yielding Rule. The correlative equation (on the bearing capacity of a structural member under bending and torsion) deduced in this study may provide valuable reference for the desima of this structural member.  相似文献   
159.
在2个量子位(qubit)的体系中,对Kane固体量子计算机模型的通过电子状态与核子自旋状态的交换进行测量的方法进行了研究。从2个量子位系统的Hamilton量出发,根据总自旋在外磁场方向的总投影分成5个不变子空间,构造它们的块对角矩阵形式。分析了它们所有的本征值和本征态随电子之间交换相互作用的大小的变化关系。结果表明:利用核自旋和电子自旋交换来测量核自旋的方法是有一定适用范围的,在2个量子位与2个电子的系统中的16个态中,只有4个可以利用这种方法来测量。  相似文献   
160.
The number of genes in the human genome is unknown, with estimates ranging from 50,000 to 90,000 (refs 1, 2), and to more than 140,000 according to unpublished sources. We have developed 'Exofish', a procedure based on homology searches, to identify human genes quickly and reliably. This method relies on the sequence of another vertebrate, the pufferfish Tetraodon nigroviridis, to detect conserved sequences with a very low background. Similar to Fugu rubripes, a marine pufferfish proposed by Brenner et al. as a model for genomic studies, T. nigroviridis is a more practical alternative with a genome also eight times more compact than that of human. Many comparisons have been made between F. rubripes and human DNA that demonstrate the potential of comparative genomics using the pufferfish genome. Application of Exofish to the December version of the working draft sequence of the human genome and to Unigene showed that the human genome contains 28,000-34,000 genes, and that Unigene contains less than 40% of the protein-coding fraction of the human genome.  相似文献   
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