全文获取类型
收费全文 | 11081篇 |
免费 | 353篇 |
专业分类
各国政治 | 489篇 |
工人农民 | 417篇 |
世界政治 | 819篇 |
外交国际关系 | 410篇 |
法律 | 6862篇 |
中国政治 | 63篇 |
政治理论 | 2290篇 |
综合类 | 84篇 |
出版年
2020年 | 128篇 |
2019年 | 168篇 |
2018年 | 242篇 |
2017年 | 228篇 |
2016年 | 246篇 |
2015年 | 171篇 |
2014年 | 198篇 |
2013年 | 1121篇 |
2012年 | 247篇 |
2011年 | 282篇 |
2010年 | 234篇 |
2009年 | 266篇 |
2008年 | 269篇 |
2007年 | 274篇 |
2006年 | 290篇 |
2005年 | 224篇 |
2004年 | 245篇 |
2003年 | 261篇 |
2002年 | 232篇 |
2001年 | 403篇 |
2000年 | 366篇 |
1999年 | 298篇 |
1998年 | 154篇 |
1997年 | 149篇 |
1996年 | 118篇 |
1995年 | 126篇 |
1994年 | 131篇 |
1993年 | 129篇 |
1992年 | 225篇 |
1991年 | 246篇 |
1990年 | 245篇 |
1989年 | 254篇 |
1988年 | 256篇 |
1987年 | 266篇 |
1986年 | 229篇 |
1985年 | 243篇 |
1984年 | 212篇 |
1983年 | 202篇 |
1982年 | 148篇 |
1981年 | 138篇 |
1980年 | 126篇 |
1979年 | 143篇 |
1978年 | 107篇 |
1977年 | 78篇 |
1976年 | 94篇 |
1975年 | 87篇 |
1974年 | 107篇 |
1973年 | 94篇 |
1972年 | 75篇 |
1969年 | 72篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
D.S.T Lo T.C Chao S.E Ng-Ong Y.J Yao T.H Koh 《Forensic Science International Supplement Series》1997,90(3):626
Blood previously acidified with aqueous saturated ammonium chloride solution was extracted with ethyl acetate. The dried extract was subjected to acetonitrile–hexane partition. The acetonitrile portion was analysed for the presence of acidic and neutral drugs by HPLC–DAD (200 mm×2.1 mm I.D. microbore ODS-Hypersil column) and GC–FID (25 m narrow-bore×0.25 mm I.D. HP-5 column with 0.33 μm film thickness). The protocol was found to be suitable for both clinical toxicology (including emergency toxicology) and postmortem toxicology. At least 66 drugs of interest were unequivocally identified by RRTs (HPLC) and UV spectra (DAD) match while another 12 were unequivocally identified by double RRTs match (HPLC and GC). Quantitation was facilitated by incorporating calibration blood standards in each assay batch. The five drugs most commonly encountered in clinical blood specimens (1150 cases) were: paracetamol (47.4% of the cases); chlormezanone (6.6%), theophylline (1.74%), naproxen (1.65%) and mefenamic acid (1.56%). The following drugs were detected in toxicologically significant quantities in postmortem blood specimens (245 cases): phenobarbitone (1.22% of the cases), naproxen (0.82%), chlormezanone (0.82%), theophylline (0.82%), carbamazepine (0.41%) and paracetamol (0.41%). 相似文献
42.
43.
44.
45.
The enzyme activity of phosphoglucomutase (PGM) has been investigated in red cell haemolysates from 142 individuals and compared to the sub-type as determined by isoelectric focusing. The 10 phenotypes showed significant differences in PGM-activity which indicates that there is a correlation between the level of activity and the isolelectric point of homozygotes. No indication of silent alleles or alleles with reduced activity was found in this collective. 相似文献
46.
Correlation between plasma and bone marrow tricyclic antidepressants has not been studied before. Two groups of rabbits were given 10 and 20 mg of desipramine/kg body weight, respectively. Desipramine was administered to the animals once daily by mouth for 5 days. On the fifth day the animals were sacrificed and blood and bone marrow samples were collected and analyzed using a high performance liquid chromatographic (HPLC) method. Data showed that a correlation exists between bone marrow and blood desipramine. The bone marrow desipramine concentration increased as its blood levels increased. The average ratio of bone marrow to blood desipramine +/- S.D. (standard deviation) in both dosage groups was 37.2 +/- 4.46 with a range of 30.99-44.82. This investigation is promising and shows that bone marrow could be used as an alternative tissue in the absence of a suitable blood sample. 相似文献
47.
W D Haglund D G Reichert D T Reay 《The American journal of forensic medicine and pathology》1990,11(1):35-43
The Green River Murder Investigation in King County, Washington, is currently the longest active serial murder investigation in U.S. history. During its course, over 26 separate scenes with from one to five victims each have been processed. The experience of the authors is presented in order to acquaint other agencies with techniques of outdoor scene processing that have evolved during recovery of remains from Green River and other skeletal cases. 相似文献
48.
49.
J W Eisele J Frisino W Haglund D T Reay 《The American journal of forensic medicine and pathology》1987,8(3):208-209
The population-adjusted rate of teenage suicide in King County, Washington, was reviewed for the 26 years from 1959 to 1984. For the entire period, the rate did not change significantly. An abrupt change did occur during the middle of this period, but, for reasons discussed in the text, this may well represent a change in procedures and philosophy of death certification rather than a real change in rate. Reasons for the apparent discrepancy with national statistics are discussed. 相似文献
50.
Samuel T. Karnick Author Vitae 《Orbis》2007,51(1):174-187