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21.
用最小二乘拟合法,将稀土区的能谱实验数据,拟合不同的能谱公式,从而证明E=a〔(1+bI(I+1))~(1/2)-1〕是符合得较好的,本文还推导了与上述能谱相应的两类转动惯量,并以此与实验计算值进行比较,结果仍很满意. 相似文献
22.
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
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24.
E. Valadé del Rio 《Cellular and molecular life sciences : CMLS》1982,38(7):790-792
Summary A mutant strain containing acinnabar allele (cn
rbr
,rojo brillante) is reported, that produces wild-type revertants at thecinnabar (cn) locus. Incn
rbr
/cn heterozygotes the rate of mutation is highly increased. The presence of a mutator agent acting premeiotically is indicated.D.L. Lindsley and E.H. Grell, Genetic variations ofDrosophila melanogaster. Carnegie Institution of Washington, Washington, 1968; Publication No. 627. 相似文献
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26.
The homeotic protein AGAMOUS controls microsporogenesis by regulation of SPOROCYTELESS 总被引:1,自引:0,他引:1
Ito T Wellmer F Yu H Das P Ito N Alves-Ferreira M Riechmann JL Meyerowitz EM 《Nature》2004,430(6997):356-360
27.
Sand can normally support a weight by relying on internal force chains. Here we weaken this force-chain structure in very fine sand by allowing air to flow through it: we find that the sand can then no longer support weight, even when the air is turned off and the bed has settled--a ball sinks into the sand to a depth of about five diameters. The final depth of the ball scales linearly with its mass and, above a threshold mass, a jet is formed that shoots sand violently into the air. 相似文献
28.
RASSF1A, the new guardian of mitosis 总被引:3,自引:0,他引:3
Máthé E 《Nature genetics》2004,36(2):117-118
29.
Essential role of Plzf in maintenance of spermatogonial stem cells 总被引:15,自引:0,他引:15
Costoya JA Hobbs RM Barna M Cattoretti G Manova K Sukhwani M Orwig KE Wolgemuth DJ Pandolfi PP 《Nature genetics》2004,36(6):653-659
30.
Léveillard T Mohand-Saïd S Lorentz O Hicks D Fintz AC Clérin E Simonutti M Forster V Cavusoglu N Chalmel F Dollé P Poch O Lambrou G Sahel JA 《Nature genetics》2004,36(7):755-759
Retinitis pigmentosa is an untreatable, inherited retinal disease that leads to blindness. The disease initiates with the loss of night vision due to rod photoreceptor degeneration, followed by irreversible, progressive loss of cone photoreceptor. Cone loss is responsible for the main visual handicap, as cones are essential for day and high-acuity vision. Their loss is indirect, as most genes associated with retinitis pigmentosa are not expressed by these cells. We previously showed that factors secreted from rods are essential for cone viability. Here we identified one such trophic factor by expression cloning and named it rod-derived cone viability factor (RdCVF). RdCVF is a truncated thioredoxin-like protein specifically expressed by photoreceptors. The identification of this protein offers new treatment possibilities for retinitis pigmentosa. 相似文献