全文获取类型
收费全文 | 96818篇 |
免费 | 620篇 |
国内免费 | 142篇 |
专业分类
化学 | 49036篇 |
晶体学 | 1431篇 |
力学 | 4058篇 |
综合类 | 12篇 |
数学 | 10803篇 |
物理学 | 32240篇 |
出版年
2022年 | 659篇 |
2021年 | 1170篇 |
2020年 | 1266篇 |
2019年 | 1545篇 |
2018年 | 2380篇 |
2017年 | 2544篇 |
2016年 | 3190篇 |
2015年 | 1453篇 |
2014年 | 2586篇 |
2013年 | 4581篇 |
2012年 | 4114篇 |
2011年 | 4550篇 |
2010年 | 4073篇 |
2009年 | 4011篇 |
2008年 | 4379篇 |
2007年 | 4188篇 |
2006年 | 3967篇 |
2005年 | 3140篇 |
2004年 | 2763篇 |
2003年 | 2345篇 |
2002年 | 2413篇 |
2001年 | 2498篇 |
2000年 | 2153篇 |
1999年 | 1545篇 |
1998年 | 1506篇 |
1997年 | 1412篇 |
1996年 | 987篇 |
1995年 | 854篇 |
1994年 | 834篇 |
1993年 | 816篇 |
1992年 | 871篇 |
1991年 | 939篇 |
1990年 | 890篇 |
1989年 | 911篇 |
1988年 | 800篇 |
1987年 | 770篇 |
1986年 | 726篇 |
1985年 | 857篇 |
1984年 | 955篇 |
1983年 | 811篇 |
1982年 | 829篇 |
1981年 | 742篇 |
1980年 | 691篇 |
1979年 | 755篇 |
1978年 | 880篇 |
1977年 | 909篇 |
1976年 | 805篇 |
1975年 | 764篇 |
1974年 | 785篇 |
1973年 | 755篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
G. S. Krinchik E. E. Chepurova B. K. Ponomarev O. P. Akhmatova A. P. Zhukov 《Russian Physics Journal》1988,31(3):250-255
The characteristics of the distribution of magnetization and remagnetization of microsections of the surface in the amorphous alloy Co70Fe5Si10B15, prepared in the form of thin ribbons, were studied by the magnetooptical method. It was found that the magnetization I on the surface of the amorphous ribbon studied was strongly nonuniform. It was established that heat treatment (HT) of the sample leads to the appearance of regions of reversed magnetization in the surface layer of the ribbon, while thermomagnetic annealing reduces the nonuniformity of I. The conservation of the transverse component in the HT sample in fields where the magnitude of the component of magnetization parallel to the length of the ribbon remains virtually unchanged suggested that a domain structure of the magnetization ripple type, owing to the strong microdispersion of the magnetic anisotropy, is realized in this sample.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 89–94, March, 1988. 相似文献
992.
V. P. Germogenov O. M. Ivleva Ya. I. Otman L. E. Épiktetova 《Russian Physics Journal》1988,31(1):73-77
Studies have been carried out on the perfection of then-AlxGa1–xSb1–yAsy (0.12x0.26) layer grown on GaSb substrates under different conditions of lattice matching. During the relaxation of the mechanical stresses at first a system of tilt dislocations with a density of up to 5 · 105 cm–2 is formed while in thick layers (h 20 m) a network of misfit dislocations parallel to the heteroboundary is formed. The time required to dissolve a weighed amount of GaAs in the melt is shown to be of major importance for obtaining layers of a solid solution that are isoperiodic with the substrate. The entry of arsenic only in the initial portion of the epitaxial layer can reduce the dislocation density in the layer without decreasing the measured value of Aa. Dissolution of a weighed amount of GaAs in a Ga + Sb melt for two hours at T=730–750°C is sufficient to obtain layers of AlxGa1–xSb1–yAsy solid solution that are isoperiodic with the substrate.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 84–89, January, 1988.In conclusion, we thank L. V. Druzhinina for useful discussions as well as Z. V. Korotchenko, L. S. Khludkova, and F. S. Kim for assistance in the performance of the experiments. 相似文献
993.
O. A. Ladyzhenskaya 《Journal of Mathematical Sciences》1990,49(5):1186-1201
Majorants of the fractal dimension and of the number of determining modes for unbounded sets, invariant with respect to operators of semigroups of classes 1 and 2, are obtained. They are computed for the Navier-Stokes equations (two- and three-dimensional) under the first boundary condition and under periodicity conditions in the spaces
and
.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 163, pp. 105–129, 1987. 相似文献
994.
We present the basic ideas, concepts, and methods of a new and promising direction that arose at the junction of differential geometry and nonassociative algebra in the 1970s and the 1980s. This direction is naturally called nonlinear geometric algebra.Translated from Itogi Nauki i Tekhniki, Seriya Problemy Geometrii, Vol. 20, pp. 75–110, 1988. 相似文献
995.
O. A. Anoshchenko 《Journal of Mathematical Sciences》1990,48(6):662-668
A theorem is proved regarding the expansion in the eigenfunctions of the one-dimensional Schrödinger equationL = –d
z/dx
2+q(x)(–<x<)with a potential q(x), satisfying the condition
相似文献
996.
N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov K. S. Belous H. Boettcher F. Botterweck M. M. Chapkin P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler A. Eskreys Z. C. Garutchava P. van Hal T. Haupt A. I. Katargin W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko K. Olkiewicz V. M. Ronjin R. Rosmalen H. M. T. Saarikko L. Scholten E. K. Shabalina J. Stepaniak O. G. Tchikilev V. A. Uvarov F. Verbeure R. Wischnewski S. A. Zotkin Y. V. Yarba EHS-NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,46(3):387-395
We report on a study of ρ0, ρ+, ω, \(\bar K^{*0} (892)\) andK *0 (892) inclusive production in π+ p interactions at 250 GeV/c, for ρ+, \(\bar K^{*0} (892)\) for the first time in a π+ p experiment. The data are compared withK + p data in the same experiment, with results of other experiments and with quark-parton models. Interesting differences are found between ρ+,0 and ω production. 相似文献
997.
J. O. Eeg 《Zeitschrift fur Physik C Particles and Fields》1990,46(4):665-670
I consider some low energy restrictions for a “flipped” left-right symmetric model containing exotic fermions ofE 6 and a right-handedW-boson, all with oddR-parity. The new interactions due toW R-exchange have no significant impact on rare kaon decays, because theW R does not couple tod,s,b quarks. On the other hand,W R exchanges might induce rare processes like \(D - \bar D\) mixing, \(D^0 \to \mu \bar \mu ,D^0 \to \mu \bar e,\mu \to e\gamma ,\mu \to 3e\) , and μN→eN. It turns out that the strongest bound is obtained from \(D - \bar D\) mixing. With reasonable extra assumptions, it is found that the exotic right-handed W-boson is likely to be heavier than 500 to 1500 GeV. 相似文献
998.
T. Ericsson A. G. Nord M. M. O. Ahmed A. Gismelseed F. Khangi 《Hyperfine Interactions》1990,57(1-4):2179-2186
Mössbauer spectra of triclinic Fe2P2O7 indicate the existence of two crystallographic metal positions in the structure. In the paramagnetic region the two Mössbauer doublets are closely overlapping. The magnetic transition takes place at ≈ 21 K and the saturated fields are around 12 tesla for the two positions. In monoclinic Fe2P4O12 the two octahedrally coordinated metal positions give quite different quadrupole splittings (1.5 and 3 mm/s at room temperature) and hyperfine field values (42 and 12.5 Tesla at 5 K). The transition temperature is at ≈ 18.5 K. 相似文献
999.
O. B. Skaskiv 《Analysis Mathematica》1990,16(2):143-157
, (fz) , ,
|
设为首页 | 免责声明 | 关于勤云 | 加入收藏 |
Copyright©北京勤云科技发展有限公司 京ICP备09084417号 |