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981.
本文根据衡量非物质文化遗产的四条标准:具有突出的历史、文化和科学价值;具有展现中华民族文化创造力的典型性和代表性;具有在一定群体中世代传承、活态存在的特点;具有鲜明特色,在当地有较大影响。结合南涧彝族“跳菜”的实际情况进行比照分析,得出了南涧彝族“跳菜”是一种非物质文化遗产的结论。 相似文献
982.
Ground granulated blast furnace slag(GGBFS)and steelmaking slag have been used as a raw material for cement production or as an aggregate to make concrete,which contribute aluminum,calcium,iron,and silicon oxides.The suitability of the slag for a particular application depends on its reactivity,cost,availability,and its influence on the properties of the resulting concrete.For the interest of durability studying of concrete in the presence of slag,the accelerated carbonation products and leaching behavior of the slag and Portland cement(PC)were studied.The experimental results confirmed that the slag was more resistant to carbonation compared to PC.The carbonation degree of GGBFS reduced by 17.74%;and the carbonation degrees of steelmaking slags reduced by 9.51%-11.94%.Carbonation neutralized the alkaline nature of the hydrated pastes and gave rise to the redox potential of the leachate slightly(30-77 mV).The carbonation also increased the release of most of the elements presented,except for calcium,to the aqueous environment.It is concluded that blend cements(PC plus slag)have economical advantages and better durability compared to PC. 相似文献
983.
The extent of linkage disequilibrium in Arabidopsis thaliana. 总被引:20,自引:0,他引:20
Magnus Nordborg Justin O Borevitz Joy Bergelson Charles C Berry Joanne Chory Jenny Hagenblad Martin Kreitman Julin N Maloof Tina Noyes Peter J Oefner Eli A Stahl Detlef Weigel 《Nature genetics》2002,30(2):190-193
Linkage disequilibrium (LD), the nonrandom occurrence of alleles in haplotypes, has long been of interest to population geneticists. Recently, the rapidly increasing availability of genomic polymorphism data has fueled interest in LD as a tool for fine-scale mapping, in particular for human disease loci. The chromosomal extent of LD is crucial in this context, because it determines how dense a map must be for associations to be detected and, conversely, limits how finely loci may be mapped. Arabidopsis thaliana is expected to harbor unusually extensive LD because of its high degree of selfing. Several polymorphism studies have found very strong LD within individual loci, but also evidence of some recombination. Here we investigate the pattern of LD on a genomic scale and show that in global samples, LD decays within approximately 1 cM, or 250 kb. We also show that LD in local populations may be much stronger than that of global populations, presumably as a result of founder events. The combination of a relatively high level of polymorphism and extensive haplotype structure bodes well for developing a genome-wide LD map in A. thaliana. 相似文献
984.
For 150 years after Galileo’s condemnation in 1633, there were many references to the trial, but no sustained, heated or polarized discussions. Then came the thesis that Galileo was condemned not for being a good astronomer but for being a bad theologian (using Scripture to support astronomical hypotheses); it began in 1784–1785 with an apology of the Inquisition by Mallet du Pan in the Mercure de France and the printing in Tiraboschi’s Storia della letteratura italiana of an apocryphal letter attributed to Galileo but forged by Onorato Gaetani. This thesis is not only untenable and false but inverts and subverts the truth; it proved to be long-lasting and widely accepted; so it may be labeled a myth. It was held by such writers as Bergier; Bergier; B; Feller; Cooper; Purcell; Marini; Reumont; Madden and Duhem. Afterwards, it was generally abandoned, its death knell being pope John Paul II’s speeches in 1979–1992. The myth seems to have acted as a catalyst insofar as its creation encouraged the proliferation of pro-clerical accounts and the articulation of pro-Galilean ones, thus making the discussion of Galileo’s trial the cause célèbre it is today. 相似文献
985.
早-中元古代Columbia超级大陆研究进展 总被引:17,自引:1,他引:17
地球在过去25亿年里曾发生过几次全球性大规模碰撞造山事件(如 Grenville事件,Pan-African事件等);地质学家由此推测大陆块自早元古代以来曾发生过周期性拼合和分离,从而导致古超级大陆的形成和裂解[1].在过去10年里(1991~2001年),被认为由约1.0 Ga Grenville造山事件所形成的超级大陆Rodinia已成为古大陆重建的一个热点[2,3].然而,地质学家们在重建Rodinia 过程中发现,并非全部Rodinia组成陆块都是由Grenville造山带所焊接,而 相似文献
986.
基质金属蛋白酶-26(MMP-26)在小鼠胚胎植入过程中的作用 总被引:2,自引:0,他引:2
基质金属蛋白酶-26(MMP-26,又称Endometase或基质水解素-2)是MMPs家族的一个新成员,它可在胎盘,子宫以及不同肿瘤细胞系中表达,采用子宫角注射,免疫组化,原位杂交,胚泡与子宫上皮单层培养,免疫印迹,RT-PCR和RNA印迹等多种体内外实验方法研究并报道了MMP-26在小鼠胚胎中的表达以及MMP-26抗体在胚胎植入中的作用,研究表明,MMP-26的mRNA与蛋白在小鼠胚泡中均有强烈的表达,此外,体内研究显示,MMP-26抗体能显著抑制小鼠胚胎的着床;在体外培养体系中,MMP-26抗体可显著抑制小鼠胚泡在子宫上皮单层上的黏附与扩展;同时,MMP-26抗体以剂量依赖关系抑制整合素αV亚基mRNA和蛋白的表达,研究提示,MMP-26可能直接或间接参与滋养层细胞侵入子宫内膜的过程,促使小鼠胚泡成功植入。 相似文献
987.
988.
目的是将用于测量片状试样的热扩散率的激光闪光法推广至测量薄膜试样。应用 1 5纳秒脉冲 Nd:YAG激光及响应时间 0 .9微秒的 (Hg,Cd) Te红外探测器等建立了闪光法热扩散率测量系统 ,并应用此系统对微米量级厚度的不锈钢薄膜进行了测量。同时针对将激光闪光法应用于薄膜时所出现的问题 ,如激光的有限脉冲时间及有限吸收厚度效应 ,测量系统的滞后效应 ,以及增强红外吸收及辐射用表面黑化膜的影响进行了分析并提出了解决方法 相似文献
989.
Marlis A Merbach Dennis J Merbach Ulrich Maschwitz Webber E Booth Brigitte Fiala Georg Zizka 《Nature》2002,415(6867):36-37
Carnivorous pitcher plants of the genus Nepenthes are not usually very selective about their prey, catching anything that is careless enough to walk on their slippery peristome, but Nepenthes albomarginata is an exception. We show here that this plant uses a fringe of edible white hairs to lure and then trap its prey, which consists exclusively of termites in enormous numbers. This singular feature accounts for the specialization of N. albomarginata for one prey taxon, unique so far among carnivorous plants. 相似文献
990.
Superoxide activates mitochondrial uncoupling proteins. 总被引:64,自引:0,他引:64
Karim S Echtay Damien Roussel Julie St-Pierre Mika B Jekabsons Susana Cadenas Jeff A Stuart James A Harper Stephen J Roebuck Alastair Morrison Susan Pickering John C Clapham Martin D Brand 《Nature》2002,415(6867):96-99
Uncoupling protein 1 (UCP1) diverts energy from ATP synthesis to thermogenesis in the mitochondria of brown adipose tissue by catalysing a regulated leak of protons across the inner membrane. The functions of its homologues, UCP2 and UCP3, in other tissues are debated. UCP2 and UCP3 are present at much lower abundance than UCP1, and the uncoupling with which they are associated is not significantly thermogenic. Mild uncoupling would, however, decrease the mitochondrial production of reactive oxygen species, which are important mediators of oxidative damage. Here we show that superoxide increases mitochondrial proton conductance through effects on UCP1, UCP2 and UCP3. Superoxide-induced uncoupling requires fatty acids and is inhibited by purine nucleotides. It correlates with the tissue expression of UCPs, appears in mitochondria from yeast expressing UCP1, and is absent in skeletal muscle mitochondria from UCP3 knockout mice. Our findings indicate that the interaction of superoxide with UCPs may be a mechanism for decreasing the concentrations of reactive oxygen species inside mitochondria. 相似文献