全文获取类型
收费全文 | 47342篇 |
免费 | 1289篇 |
国内免费 | 42篇 |
专业分类
化学 | 28741篇 |
晶体学 | 244篇 |
力学 | 764篇 |
综合类 | 1篇 |
数学 | 8910篇 |
物理学 | 10013篇 |
出版年
2023年 | 334篇 |
2022年 | 323篇 |
2021年 | 510篇 |
2020年 | 695篇 |
2019年 | 629篇 |
2018年 | 950篇 |
2017年 | 869篇 |
2016年 | 1690篇 |
2015年 | 1411篇 |
2014年 | 1365篇 |
2013年 | 3079篇 |
2012年 | 2897篇 |
2011年 | 2736篇 |
2010年 | 1839篇 |
2009年 | 1556篇 |
2008年 | 2416篇 |
2007年 | 2192篇 |
2006年 | 1972篇 |
2005年 | 2012篇 |
2004年 | 1728篇 |
2003年 | 1444篇 |
2002年 | 1266篇 |
2001年 | 964篇 |
2000年 | 986篇 |
1999年 | 688篇 |
1998年 | 524篇 |
1997年 | 450篇 |
1996年 | 596篇 |
1995年 | 429篇 |
1994年 | 493篇 |
1993年 | 449篇 |
1992年 | 474篇 |
1991年 | 404篇 |
1990年 | 450篇 |
1989年 | 364篇 |
1988年 | 375篇 |
1987年 | 333篇 |
1986年 | 325篇 |
1985年 | 452篇 |
1984年 | 412篇 |
1983年 | 327篇 |
1982年 | 328篇 |
1981年 | 343篇 |
1980年 | 281篇 |
1979年 | 276篇 |
1978年 | 273篇 |
1977年 | 262篇 |
1976年 | 278篇 |
1974年 | 251篇 |
1973年 | 263篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
A simple analytical model is developed and solved to describe time evolution of the loop voltage and toroidal current when RF and inductive current drive take place simultaneously. A relation for the real value of the RF driven current has been obtained under these conditions. Comparison with experimental data from T-7 tokamak allows to estimate the role of the skin effect during RF current drive.The authors would like to thank A. Ya. Kislov for the basic data on the T-7 tokamak transformer. They are also indebted to V. V. Parail and G.V. Pereverzev for many clarifying discussions. 相似文献
122.
B. Barabás 《Periodica Mathematica Hungarica》1987,18(2):115-122
The properties of the empirical density function,f
n(x) = k/n(
j
+
–
j-1
+
) if
j-1
+
< x + where
j-1
+
and
j
+
are sample elements and there are exactlyk – 1 sample elements between them, are studied in that practical point of view how to choose a suitablek for a good estimation. A bound is given for the expected value of the absolute value of difference between the empirical and theoretical density functions. 相似文献
123.
L. Eckertová 《Czechoslovak Journal of Physics》1987,37(6):749-758
A simple model including different processes important for the creation of APS signals formed by electrons is proposed. Mean probabilities of elastic and inelastic interactions of electrons with individual atom layers in the solid are introduced. The contribution of different layers to the DAPS and AEPS signals and the dependence of these signals on the interaction parameters are calculated.I am indebted to dr. J. Pavluch for valuable discussions. 相似文献
124.
L. Avanov N. Borodkova Z. NĚmeček A. Omeltchenko J. Šafránková A. Skalski Yu. Yermolaev G. Zastenker 《Czechoslovak Journal of Physics》1987,37(6):759-774
The paper describes the results of investigations of the solar wind ions, carried out on board the high apogee Prognoz 7 and Prognoz 8 Earth's satellites with the aid of an SKS instrument (USSR) and a Monitor instrument (USSR-SSR). Behaviour of proton and that of components on the front of Earth's bow and interplanetary shock waves were compared by means of the energoanalysis and energy-mass analysis techniques. In several long-term periods of observation the solar wind heavy ions — oxygen, silicon and iron were determined. It enabled us to estimate the solar corona chemical composition and electron temperature.Presented at the 5th General Assembly IAGA/IAMAP August 5–17, 1985, Prague, Czechoslovakia. 相似文献
125.
The dependence of the flow stress and the slip band density on the plastic strain has been measured at 201 K, 293 K and 363 K. The growth of deformation concentrated in an average slip band has been stated. The types of obstacles acting against the rise and development of a slip band and the temperature dependence of the strain hardening in AgCl crystals are discussed. An equation stating the dependence of the flow stress on the slip band density is presented. The hardening in AgCl crystals is classified as the stage III — hardening. 相似文献
126.
Martin Macháček 《Journal of statistical physics》1987,47(5-6):949-952
We define mathematically a class of dynamical systems that exhibit relaxation corresponding to that observed in physical systems, and then show that this class is identical with the class ofK-mixing dynamical systems. 相似文献
127.
128.
129.
J. Kuriplach L. Lešták M. Rotter B. Sedlák M. Trhlík M. Finger T. Lešner J. Dupák P. Novák M. Vobecký 《Hyperfine Interactions》1987,34(1-4):339-342
First experimental results of160Tb nuclear orientation in yttrium single crystal matrix are described. The influence of external magnetic field in combination with the crystal field interaction is discussed. 相似文献
130.
J. Bendahán C. Broude E. Dafni G. Goldring M. Hass E. Naim M. H. Rafailovich 《Hyperfine Interactions》1987,34(1-4):139-142
The parity-violating mixing of the 17/2– and 17/2+ levels in93Tc nuclei, polarized by the tilted multifoil interaction, was measured by the observation of the forward-backward-ray asymmetry. The nuclear polarization, induced by the tilted multifoils, was measured directly for the neighboring88,90Zr isomers. The forward to backward asymmetry was determined to be A=(2.5±2.1) 10–3 which implies a parity violating matrix element ¦H
PV
)¦=(4.0±3.7)meV. 相似文献