全文获取类型
收费全文 | 12236篇 |
免费 | 2180篇 |
国内免费 | 3958篇 |
专业分类
化学 | 9966篇 |
晶体学 | 399篇 |
力学 | 755篇 |
综合类 | 440篇 |
数学 | 1885篇 |
物理学 | 4929篇 |
出版年
2024年 | 36篇 |
2023年 | 188篇 |
2022年 | 447篇 |
2021年 | 459篇 |
2020年 | 509篇 |
2019年 | 496篇 |
2018年 | 402篇 |
2017年 | 559篇 |
2016年 | 538篇 |
2015年 | 640篇 |
2014年 | 769篇 |
2013年 | 983篇 |
2012年 | 1067篇 |
2011年 | 1076篇 |
2010年 | 919篇 |
2009年 | 996篇 |
2008年 | 1052篇 |
2007年 | 945篇 |
2006年 | 898篇 |
2005年 | 802篇 |
2004年 | 674篇 |
2003年 | 539篇 |
2002年 | 588篇 |
2001年 | 561篇 |
2000年 | 505篇 |
1999年 | 344篇 |
1998年 | 166篇 |
1997年 | 124篇 |
1996年 | 131篇 |
1995年 | 123篇 |
1994年 | 133篇 |
1993年 | 100篇 |
1992年 | 98篇 |
1991年 | 70篇 |
1990年 | 68篇 |
1989年 | 58篇 |
1988年 | 53篇 |
1987年 | 52篇 |
1986年 | 47篇 |
1985年 | 17篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 11篇 |
1981年 | 24篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1965年 | 2篇 |
1959年 | 5篇 |
1957年 | 5篇 |
1936年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
SHI Yingtian SHI Bingren 《核工业西南物理研究院年报(英文版)》2004,(1):133-134
The safety most important factor profile is one of the the plasma discharge. For limiter configuration, people usually use the following cylindrical approximation formula to calculate it q(r)=5r^2BT/RIp where r is the minor radius of the plasma toms, R is the major radius (in m) , BT is the toroidal magnetic field (in T), Ip is the total toroidal current(in MA). 相似文献
32.
HL-2A tokamak, the first tokamak with divertor in China, has been constructed and put into operation in 2002. The main parameters are R=1.65 m, a=0.4 m, BT=2.8 T, Ip = 0. 48 MA. The divertor of HL-2A is unique, because it is characterized with a large closed divertor chamber. The device has double divertor chamber, but now it is operating with lower single null configuration to study the physics of divertor for the next step design of a divertor. Supersonic molecular beam injection (SMBI) system with LN2 cooling trap was first installed and demonstrated on the HL-2A tokamak in 2004. The first results of SMBI into HL-2A plasma are to demonstrate the function of the HL-2A divertor and to observe the cold pulse propagation during multi-pulse SMBI on HL-2A Tokamak. 相似文献
33.
SHI Bingren LI Jiquan DONG Jiaqi 《核工业西南物理研究院年报(英文版)》2004,(1):115-118
The geodesic acoustic mode (GAM), first predicted by Winsor, Johnson and Dawson in an attempt to explain some experimentally observed low frequency oscillations in stellarators, is a special electrostatic fluid mode with low mode number and coupled with the so-called geodesic curvature of a toroidally confined plasma. The recent on this mode are due to the close relevance of the stabi- lization of drift turbulence by both the zonal flow and the GAM. Previously, the GAM was illustrated in very simple geometries, 相似文献
34.
μ子动量谱的精确测量是L3C宇宙线实验最重要的目标之一.事例重建的好坏是该测量的关键,而能量确定的衰变为双μ子的事例是检验重建程序的最好手段.该数据分析利用在2000年中获取的数据作为样本,筛选出了LEP在2000年4月、5月、8月和9月等Z0能量运行期间L3C宇宙线实验数据中记录的Z0→μ+μ-事例数据,得到通过重建程序后动量为45GeV的μ子动量分辨率为(5.4?7±0.25)%. 相似文献
35.
36.
37.
This paper is a contionuation of [1] and is concerned with multiplication of weak functions. Here the weak functions are treated as generalized expansions in Hermite functions in [2]. 相似文献
38.
B-Spline with Symplectic Algorithm Method for Solution of Time-Dependent Schrodinger Equations 下载免费PDF全文
A B-spline with the symplectic algorithm method for the solution of time-dependent Schrodinger equations (TDSEs) is introduced. The spatial part of the wavefunction is expanded by B-spline and the time evolution is given in a symplectic scheme. This method allows us to obtain a highly accurate and stable solution of TDSEs. The effectiveness and efficiency of this method is demonstrated by the high-order harmonic spectra of one-dimensional atoms in comparison with other references. 相似文献
39.
The segregation of P at grain boundaries is believed to be an important cause of temper embrittlement in steels. As an alloy element, Mo may reduce the embrittlement. However, the concentration measured by Auger electron spectroscopy at the grain boundary in 2.25Cr1MoV and 12Cr1MoV showed that the concentration of P increased with that of Mo, which indicates that Mo and P cosegregated to the grain boundary in Cr-Mo steels. 相似文献
40.
本文给出Turán第24个问题的完全解:若Hermite-Fejer插值过程对任何都一致收敛,则定义在同一节点上的Lagrange插值过程对每个Lipα都一致收敛,其中α≈0.988。 相似文献