全文获取类型
收费全文 | 455篇 |
免费 | 7篇 |
国内免费 | 4篇 |
专业分类
化学 | 230篇 |
晶体学 | 9篇 |
力学 | 20篇 |
数学 | 24篇 |
物理学 | 183篇 |
出版年
2021年 | 3篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 16篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 12篇 |
2007年 | 24篇 |
2006年 | 24篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 15篇 |
2001年 | 10篇 |
2000年 | 19篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1996年 | 5篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 23篇 |
1992年 | 20篇 |
1991年 | 7篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1968年 | 4篇 |
1936年 | 2篇 |
1934年 | 3篇 |
1933年 | 2篇 |
1929年 | 2篇 |
1927年 | 2篇 |
1917年 | 4篇 |
1890年 | 2篇 |
1889年 | 2篇 |
1885年 | 2篇 |
排序方式: 共有466条查询结果,搜索用时 218 毫秒
71.
72.
A model of the renal medulla introduced by Shohet and Pinter takes the form of a linear two point boundary value problem. It is shown that this boundary value problem can be reduced to an initial value problem, which is of analytical interest and of computational utility. 相似文献
73.
R. Webb G. Trilling V. Telegdi P. Strolin A. Staude B. Shen P. Schlein J. Rander B. Naroska F. Muller T. Meyer W. Marsh W. Lockman J. Layter A. Kernan H. Foeth R. Ellis A. Böhm L. Baksay 《Physics letters. [Part B]》1975,55(3):336-340
We report the observation of double diffraction dissociation in the process p + p → (pπ+π?) + X at √s of 45 GeV and momentum transfer in the ?t range 0.15?0.53 GeV2 at the CERN ISR. The relative rates for elastic, single and double dissociation reactions measured here are found to agree with the prediction of Pomeron factorization. 相似文献
74.
Future development of more efficient turbomachinery depends on improving understanding of the fluid mechanics. This paper reviews advances made in the last five years in calculation methods for steady flow, unsteady flows and stability, and instrumentation and its applications. Fundamental problems which need further study are also indicated 相似文献
75.
Uranium(VI) is selectively determined by a compleximetric titration with pyridine-2,6-dicarboxylic acid, using arsenazo-I indicator and hexamethylenetetramine buffer at pH 4.9. Cyclohexanediaminetetraacetic acid and diethylenetriaminepentaacetic acid provide masking of interfering metal ions. A probe colorimeter apparatus is recommended for end-point detection. The relative standard deviation is 0.6% for 0.17–0.76 μmol of uranium. 相似文献
76.
77.
78.
79.
80.
K.J. Marsh 《Applied Acoustics》1982,15(6):411-428
This paper describes a propagation model for calculating neighbourhood-noise from open-air industrial plants such as oil refineries and petrochemical plants. It was developed from a preliminary model derived from a comprehensive survey of the literature on noise propagation. The aim was to develop a model which used parameters and procedures available to engineers engaged in plant design. An experimental programme of measurements was carried out around three industrial plants over a period of about one year and this was used to modify the original model. The final model is based on six meteorological categories and contains separate attenuation values for spherical spreading, atmospheric absorption, ground effects, meteorological category, source/receiver height, and barrier effects. They are given as a function of frequency and distance, either as graphs or as polynomial equations for computer calculations.A statistical assessment has been made to establish the confidence limits of the predictions in dB(A) and in octave bands from 63 Hz to 4 kHz. They are compared with the confidence limits of predictions by two other propagation models frequently used in Europe (OCMA and VDI) and are found to be significantly better. 相似文献