全文获取类型
收费全文 | 2276篇 |
免费 | 51篇 |
国内免费 | 11篇 |
专业分类
化学 | 1638篇 |
晶体学 | 26篇 |
力学 | 29篇 |
数学 | 100篇 |
物理学 | 545篇 |
出版年
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 17篇 |
2019年 | 23篇 |
2018年 | 23篇 |
2016年 | 25篇 |
2015年 | 40篇 |
2014年 | 53篇 |
2013年 | 95篇 |
2012年 | 116篇 |
2011年 | 117篇 |
2010年 | 57篇 |
2009年 | 79篇 |
2008年 | 115篇 |
2007年 | 129篇 |
2006年 | 125篇 |
2005年 | 129篇 |
2004年 | 75篇 |
2003年 | 85篇 |
2002年 | 82篇 |
2001年 | 55篇 |
2000年 | 36篇 |
1999年 | 23篇 |
1998年 | 33篇 |
1997年 | 27篇 |
1996年 | 33篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 40篇 |
1991年 | 27篇 |
1990年 | 41篇 |
1989年 | 30篇 |
1988年 | 34篇 |
1987年 | 39篇 |
1986年 | 34篇 |
1985年 | 42篇 |
1984年 | 40篇 |
1983年 | 23篇 |
1982年 | 31篇 |
1981年 | 25篇 |
1980年 | 18篇 |
1979年 | 26篇 |
1978年 | 25篇 |
1977年 | 34篇 |
1976年 | 14篇 |
1975年 | 19篇 |
1974年 | 26篇 |
1973年 | 18篇 |
排序方式: 共有2338条查询结果,搜索用时 15 毫秒
61.
62.
63.
Hirozumi Fujii 《Proceedings of the American Mathematical Society》1996,124(9):2923-2933
It is well-known that any Laurent polynomial satisfying and is the Alexander polynomial of a knot in . We show that can be realized by a knot which has the following properties simultaneously: (i) tunnel number 1; (ii) bridge index 3; and (iii) unknotting number 1.
64.
65.
66.
Allen WH Bond IA Budding E Conway MJ Daniel A Fenton KB Fujii H Fujii Z Hayashida N Hibino K Honda M Humble JE Kabe S Kasahara K Kifune T Lythe GD Masaike A Matsubara Y Mitsui K Miura Y Mori M Muraki Y Nagano M Nakamura T Nishizawa M Morris PM Ogio S Saito T Sakata M Sato H Shimizu HM Spencer M Storey JR Tanimori T Teshima M Torii S Wadsworth A Watase Y Woodhams MD Yamamoto Y Yock PC Yuda T 《Physical review D: Particles and fields》1993,48(2):466-478
67.
Several beta-secretase inhibitors were designed based on hydroxyethylamine dipeptide isostere (HDI) structures and were synthesized by a methodology using the aza-Payne rearragement and O,N-acyl transfer reactions to study their structure-activity relationships. Among these pseudopeptides, effective compounds were developed as the first beta-secretase inhibitors containing the HDI transition state mimic with potent enzyme inhibitory activity (IC50 < 100 nM). 相似文献
68.
The common synthetic intermediate of a potent and promising anticancer agent, fostriecin, was synthesized using a unique method that combines four catalytic asymmetric reactions as shown above. 相似文献
69.
The simultaneous ultramicrodetermination of heterogeneous halogens in organic compounds was carried out by the potentiometric titration with 0.002 M silver nitrate after the sample was decomposed by the flask combustion method. In examination of the titration, it was found that clear potential break at the end point was obtained by controlling the delivery speed of the titrant at 0.2 ml/min or slower and the temperature of the solution to be titrated at ca. 10 °C when chloride ion is present. The error due to coprecipitation during the titration and the effect of the mole ratio of heterogeneous halide ions in the sample solution was examined and discussed. The analysis of organic halogen compounds resulted in an error of within 0.4% and standard deviation of less than 0.25%. 相似文献
70.
Aihara H Alston-Garnjost M Bakken JA Barbaro-Galtieri A Barnes AV Barnett BA Bengtsson H Blumenfeld BJ Bross AD Buchanan CD Chamberlain O Chien C Clark AR Cordier A Dahl OI Day CT Derby KA Eberhard PH Fancher DL Fujii H Fujii T Gabioud B Gary JW Gorn W Hadley NJ Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kenney RW Kerth LT Koda RI Kofler RR Kwong KK Layter JG Lindsey CS Loken SC Lu X Lynch GR Madansky L Madaras RJ Maruyama K Marx JN Matthews JA Melnikoff SO Moses W Nemethy P 《Physical review letters》1985,54(4):270-273