全文获取类型
收费全文 | 42230篇 |
免费 | 3748篇 |
国内免费 | 205篇 |
专业分类
46183篇 |
出版年
2018年 | 502篇 |
2017年 | 487篇 |
2016年 | 623篇 |
2015年 | 712篇 |
2014年 | 920篇 |
2013年 | 1100篇 |
2012年 | 1243篇 |
2011年 | 1286篇 |
2010年 | 868篇 |
2009年 | 875篇 |
2008年 | 1184篇 |
2007年 | 1186篇 |
2006年 | 1193篇 |
2005年 | 1024篇 |
2004年 | 983篇 |
2003年 | 923篇 |
2002年 | 902篇 |
2001年 | 2788篇 |
2000年 | 2460篇 |
1999年 | 1810篇 |
1998年 | 616篇 |
1997年 | 527篇 |
1996年 | 476篇 |
1995年 | 402篇 |
1994年 | 388篇 |
1992年 | 1286篇 |
1991年 | 1162篇 |
1990年 | 1100篇 |
1989年 | 1050篇 |
1988年 | 934篇 |
1987年 | 927篇 |
1986年 | 804篇 |
1985年 | 796篇 |
1984年 | 565篇 |
1983年 | 517篇 |
1982年 | 370篇 |
1979年 | 636篇 |
1978年 | 460篇 |
1977年 | 418篇 |
1976年 | 372篇 |
1975年 | 496篇 |
1974年 | 578篇 |
1973年 | 554篇 |
1972年 | 572篇 |
1971年 | 550篇 |
1970年 | 521篇 |
1969年 | 528篇 |
1968年 | 428篇 |
1967年 | 375篇 |
1966年 | 412篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
122.
123.
A total of 626 patients undergoing a prostaglandin-induced abortion, the majority in the second trimester, have been analysed for complications occurring during inpatient treatment. Of the last 155 consecutive patients 143 were critically assessed six to eight weeks after abortion for morbidity occurring during their early recovery period.Blood loss of 250 ml or more occurred in 68 patients, pyrexia in 34, pelvic infection in three, and readmission in 14 of the 626 patients studied, and a transfusion was required in eight.Bleeding after abortion stopped within six weeks in all 143 of the 155 consecutive patients assessed but three required readmission for uterine curettage. Menstruation was re-established within six weeks of abortion in 106 patients.The incidence of operative morbidity was similar to that reported for first trimester abortion and better than that in most reported series of second trimester abortions. 相似文献
124.
125.
126.
127.
N. E. Belyaeva V. Z. Pashchenko G. Renger G. Yu. Riznichenko A. B. Rubin 《Biophysics》2006,51(6):860-872
A mathematical model of photosystem II (PSII) events was used to analyze chlorophyll fluorescence transients in the time domain from 100 ns to 10 s after excitation with a saturating 10-ns flash, applied as a part of specialized illumination protocol, using preparations of a thermophilic strain of the unicellular green alga, Chlorella pyrenoidosa Chick (using both intact and diuron-treated cells). Analysis of simulation results has proven that particular attention should be given to flash-induced recombination processes, including nonradiative recombination in PSII, while subsequent charge transfer along the electron transport chain of thylakoid membrane can be adequately described by a single reaction of quinone reoxidation. The PSII model was extended by taking inhibition by diuron of the electron transport in the acceptor side of PSII into account, which allowed simulation of fluorescence induction curves observed in the presence of this inhibitor. The model parameters were determined (stromal pH, rate constants of nonradiative recombination, and the initial reduction state of the quinone pool) which provided adequate simulation of experimentally observed ratios of the maximal and initial fluorescence levels (F m/F 0). 相似文献
128.
129.
WIKTOR Z 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1952,7(27-28):908-915
130.