全文获取类型
收费全文 | 57344篇 |
免费 | 4184篇 |
国内免费 | 2964篇 |
专业分类
化学 | 30127篇 |
晶体学 | 537篇 |
力学 | 3272篇 |
综合类 | 287篇 |
数学 | 12166篇 |
物理学 | 18103篇 |
出版年
2024年 | 73篇 |
2023年 | 571篇 |
2022年 | 587篇 |
2021年 | 867篇 |
2020年 | 1116篇 |
2019年 | 1067篇 |
2018年 | 2038篇 |
2017年 | 2199篇 |
2016年 | 1908篇 |
2015年 | 1709篇 |
2014年 | 1930篇 |
2013年 | 2601篇 |
2012年 | 5632篇 |
2011年 | 4918篇 |
2010年 | 3427篇 |
2009年 | 3149篇 |
2008年 | 2259篇 |
2007年 | 2232篇 |
2006年 | 2063篇 |
2005年 | 5600篇 |
2004年 | 4810篇 |
2003年 | 3049篇 |
2002年 | 1216篇 |
2001年 | 838篇 |
2000年 | 644篇 |
1999年 | 819篇 |
1998年 | 686篇 |
1997年 | 644篇 |
1996年 | 706篇 |
1995年 | 547篇 |
1994年 | 504篇 |
1993年 | 409篇 |
1992年 | 539篇 |
1991年 | 474篇 |
1990年 | 389篇 |
1989年 | 308篇 |
1988年 | 256篇 |
1987年 | 191篇 |
1986年 | 166篇 |
1985年 | 154篇 |
1984年 | 115篇 |
1983年 | 86篇 |
1982年 | 59篇 |
1981年 | 54篇 |
1976年 | 99篇 |
1975年 | 65篇 |
1974年 | 67篇 |
1973年 | 59篇 |
1972年 | 53篇 |
1969年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Bai JZ Bardon O Blum I Breakstone A Burnett T Chen GP Chen HF Chen J Chen SJ Chen SM Chen Y Chen YB Chen YQ Cheng BS Cowan RF Cui HC Cui XZ Ding HL Du ZZ Dunwoodie W Fan XL Fang J Fero M Gao CS Gao ML Gao SQ Gao WX Gratton P Gu JH Gu SD Gu WX Gu YF Guo YN Han SW Han Y Harris FA Hatanaka M He J He KR He M Hitlin DG Hu GY Hu HB Hu T Hu XQ Huang DQ Huang YZ Izen JM Jia QP Jiang CH Jin Y Jones L Kang SH Kelsey MH Kim BK Lai YF Lan HB Lang PF Lankford A Li F Li J Li PQ Li Q Li RB 《Physical review D: Particles and fields》1995,52(7):3781-3784
992.
993.
Residual stresses are found in the majority of multilayer thin film structures used in modem technology. The measurement and modeling of such stress fields and the elucidation of their effects on structural reliability and device operation have been a “growth area” in the literature, with contributions from authors in various scientific and engineering disciplines.
In this article the measurement of the residual stresses in thin film structures with X-ray diffraction techniques is reviewed and the interpretation of such data and their relationship to mechanical reliability concerns are discussed. 相似文献
994.
?. ?upi? S. Anic A. Terlecki-Bari?evi? Lj. Kolar-Ani? 《Reaction Kinetics and Catalysis Letters》1995,54(1):43-49
Behavior of the Bray-Liebhafsky oscillatory reaction in the presence of acid-base polymers with and without ferric ions is analyzed. The influence of hydrogen ions on the overall reaction is shown. 相似文献
995.
黄干平 《武汉大学学报(理学版)》1994,(1)
并行“冒泡”排序算法的改进黄干平(武汉大学计算机科学系,武汉,430072)关键词排序,并行算法,冒泡中国法分类号w301.6PBSM并行排序算法是对KazuhirsSado和YoshihideIgarash的并行“冒泡’书r序算法’“的改进,其并行... 相似文献
996.
The effects of media properties including buffers, acidity, solvents and surfactant on horseradish peroxidase-catalyzed fluorogenic reaction were investigated. The results showed that the so-called non-fluorescent hydrogen donors were in fact fluorescent. There existed an acid—base equilibrium in the fluorescent dimer product. For p -hydroxyphenylpropionic acid, a pKa value of 8.0 for the product was obtained from its titration curve. The product fluorescence increased with higher pH, however, a longer time was needed to reach the reaction equilibrium due to the pH mismatch problem. Cationic micelles cetyltrimethylammonium bromide and cetyltrimethylammonium chloride could reduce the pH mismatch and offered a way to further increase the determination sensitivity. Finally, a micelle-enhanced flow-injection analysis of horseradish peroxidase is suggested. 相似文献
997.
998.
999.
1000.
J. B?chler J. Bartke H. Bia?kowska R. Bock D. Brinkmann R. Brockmann P. Buncic S. I. Chase I. Derado V. Eckardt et al. 《Zeitschrift fur Physik C Particles and Fields》1994,61(4):551-561
The intermittency phenomenon is investigated in proton-gold, oxygen-gold, sulphur-gold and sulphur-sulphur collisions at 200 GeV per nucleon. The data were taken with the NA 35 streamer chamber detector at the CERN SPS. The data samples are carefully corrected for double counting of tracks and for contamination from photon conversions, particle decays and secondary interactions. The analysis is carried out in terms of factorial moments, using a new definition, and of correlation integrals. Both methods show the presence of nonstatistical fluctuations (intermittency). The main conclusions are: The observation of the effect for pairs of hadrons with negative charges and its near absence for pairs of opposite charges is consistent with the assumption that Bose-Einstein correlations yield the dominant contribution. The intermittency effect is not proportional to (dn/dy)–1 which would be expected in superposition models. The measured relation between the second and third factorial moment for negative hadrons indicates that genuine 3-particle correlations are small. The predictions of a Monte Carlo simulation which is based on the Lund Fritiof model with the inclusion of Bose-Einstein correlations agree with the experimental results.Deceased 相似文献