全文获取类型
收费全文 | 474910篇 |
免费 | 2449篇 |
国内免费 | 743篇 |
专业分类
化学 | 213634篇 |
晶体学 | 7048篇 |
力学 | 28632篇 |
综合类 | 13篇 |
数学 | 75907篇 |
物理学 | 152868篇 |
出版年
2021年 | 4075篇 |
2020年 | 4412篇 |
2019年 | 5341篇 |
2018年 | 12585篇 |
2017年 | 12894篇 |
2016年 | 12639篇 |
2015年 | 5198篇 |
2014年 | 9155篇 |
2013年 | 17473篇 |
2012年 | 16788篇 |
2011年 | 24026篇 |
2010年 | 17537篇 |
2009年 | 18008篇 |
2008年 | 22189篇 |
2007年 | 24268篇 |
2006年 | 14084篇 |
2005年 | 15258篇 |
2004年 | 13262篇 |
2003年 | 12825篇 |
2002年 | 11876篇 |
2001年 | 11261篇 |
2000年 | 8919篇 |
1999年 | 6558篇 |
1998年 | 5967篇 |
1997年 | 5865篇 |
1996年 | 5524篇 |
1995年 | 4792篇 |
1994年 | 4933篇 |
1993年 | 4902篇 |
1992年 | 5099篇 |
1991年 | 5531篇 |
1990年 | 5400篇 |
1989年 | 5418篇 |
1988年 | 5192篇 |
1987年 | 5194篇 |
1986年 | 4866篇 |
1985年 | 5893篇 |
1984年 | 6182篇 |
1983年 | 5228篇 |
1982年 | 5423篇 |
1981年 | 5097篇 |
1980年 | 4714篇 |
1979年 | 5443篇 |
1978年 | 5475篇 |
1977年 | 5655篇 |
1976年 | 5734篇 |
1975年 | 5383篇 |
1974年 | 5211篇 |
1973年 | 5457篇 |
1972年 | 4416篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
871.
Yu. V. Sokolova 《Russian Journal of Applied Chemistry》2006,79(4):573-578
Kinetics of Sc(III) sorption from hydrochloric acid solutions on KRF-20t-60 cation exchanger is studied. The experimental data are analyzed in terms of the gel and film kinetic models. The Sc(III) diffusion coefficient in the resin phase is estimated. Static and dynamic sorption data are obtained on Sc(III) sorption from various process solutions on KRF-20t-60, PA-1, AFI-22 ion exchangers, and also on ion exchangers supported on polyacrylonitrile-based fibrous material. Desorption of Sc(III) from KRF-20t-60 is also studied. 相似文献
872.
873.
S.A. Masti A.K. Sharma P.N. Vasambekar A.S. Vaingankar 《Journal of magnetism and magnetic materials》2006
Magnetization and permeability of polycrystalline ferrites with general formula CdxMg1−xFe2−yCryO4 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0, 0.05 and 0.10) were studied. Study of saturation magnetization reveals that the Neel's two-sublattice model exists upto x=0.4, for y=0, 0.05 and 0.1 and a three-sublattice model (YK-model) is predominant for x>0.4 and y=0, 0.05 and 0.10. The saturation magnetization and magnetic moment were found to decrease with the increase in Cr3+ contents, which is attributed to the dilution of B–B site interaction. Variation of initial permeability with temperature revealed the long-range ferromagnetic ordering in the compounds with x=0.4. The sample with x?0.4 and y=0, 0.05 and 0.10 showed peaking behavior near Curie temperature, which is attributed to the decrease of anisotropy constant K1 to zero. Low-frequency dispersion of initial permeability suggests domain wall displacement. Addition of Cd2+ resulted in a sharp decrease in Curie temperature. With the addition of Cr3+, initial permeability was found to decrease. 相似文献
874.
N. Hegyvári 《Acta Mathematica Hungarica》1989,53(1-2):149-154
875.
876.
D. Fong J. H. Hamilton A. V. Ramayya J. K. Hwang C. Goodin K. Li J. Kormicki J. O. Rasmussen Y. X. Luo S. C. Wu I. Y. Lee A. V. Daniel G. M. Ter-Akopian G. S. Popeko A. S. Fomichev A. M. Rodin Yu. Ts. Oganessian M. Jandel J. Kliman L. Krupa J. D. Cole M. A. Stoyer R. Donangelo W. C. Ma 《Physics of Atomic Nuclei》2006,69(7):1161-1167
The hot bimodal fission of 252Cf is reexamined with new high-statistics data. We constructed a γ-γ-γ coincidence cube for binary fission and LCP-gated γ-γ matrix for ternary fission. By identifying the secondary fission fragments from their γ-ray transitions, we measured the yields for various fission splits. The normal neutron yield distribution is found to be
Gaussian for Xe-Ru. However, the binary fission split of Ba-Mo is found to exhibit a bimodal neutron distribution with the
“hot mode” corresponding to ≈3.1% of the total yield. In α ternary fission, the first measurements of yields for specific fission splits are presented. The Te-α-Ru and Xe-α-Mo neutron yields fit well with a single mode, but the Ba-α-Zr split shows evidence for an enhanced hot mode with an intensity of ≈13.8% of the normal mode.
The text was submitted by the authors in English. 相似文献
877.
878.
I. G. Silinskaya A. V. Novoselova Yu. N. Sazanov A. V. Gribanov I. N. Serov V. I. Margolin 《Russian Journal of Applied Chemistry》2006,79(8):1378-1380
Mechanisms of orientation for the solutions of polyacrylonitrile synthesized under conditions of radical and anionic polymerization were studied. The effect of the fractal-matrix structuring agent developed by the AIRES foundation on the correlation parameters of the solution density and average squared fluctuation polarizability, which can be used to determine how the supramolecular structure changes by “self-orientation” and “induced orientation” mechanisms, was analyzed. 相似文献
879.
A. Yu. Shvykin V. V. Platonov V. A. Proskuryakov K. B. Chilachava S. I. Podshibyakin 《Russian Journal of Applied Chemistry》2006,79(10):1576-1580
A method of synthesis of acetylacetonated humin-like compounds was developed. The effect of modification on the sorption capacity of humin-like compounds with respect to heavy metals was studied. 相似文献
880.
T. Yu. Gumerov A. F. Dobrynina R. A. Yusupov V. P. Barabanov 《Russian Journal of Applied Chemistry》2006,79(12):1935-1939
The behavior of real disperse systems with organic impurities was examined under conditions of destabilization by inorganic coagulants. A number of physicochemical methods of analysis and a simulation method were used to identify the character and type of the complexes formed and to calculate their stability constants. 相似文献