全文获取类型
收费全文 | 10835篇 |
免费 | 308篇 |
国内免费 | 9篇 |
专业分类
各国政治 | 676篇 |
工人农民 | 449篇 |
世界政治 | 762篇 |
外交国际关系 | 510篇 |
法律 | 5799篇 |
中国共产党 | 121篇 |
中国政治 | 358篇 |
政治理论 | 2010篇 |
综合类 | 467篇 |
出版年
2021年 | 61篇 |
2020年 | 163篇 |
2019年 | 147篇 |
2018年 | 217篇 |
2017年 | 255篇 |
2016年 | 244篇 |
2015年 | 233篇 |
2014年 | 244篇 |
2013年 | 1202篇 |
2012年 | 313篇 |
2011年 | 431篇 |
2010年 | 360篇 |
2009年 | 376篇 |
2008年 | 384篇 |
2007年 | 387篇 |
2006年 | 378篇 |
2005年 | 332篇 |
2004年 | 285篇 |
2003年 | 277篇 |
2002年 | 212篇 |
2001年 | 397篇 |
2000年 | 358篇 |
1999年 | 307篇 |
1998年 | 157篇 |
1997年 | 113篇 |
1996年 | 124篇 |
1995年 | 109篇 |
1994年 | 118篇 |
1993年 | 112篇 |
1992年 | 169篇 |
1991年 | 162篇 |
1990年 | 155篇 |
1989年 | 146篇 |
1988年 | 168篇 |
1987年 | 161篇 |
1986年 | 166篇 |
1985年 | 151篇 |
1984年 | 149篇 |
1983年 | 159篇 |
1982年 | 101篇 |
1981年 | 72篇 |
1980年 | 85篇 |
1979年 | 99篇 |
1978年 | 80篇 |
1977年 | 67篇 |
1976年 | 69篇 |
1975年 | 58篇 |
1972年 | 53篇 |
1971年 | 54篇 |
1969年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Marianne Junger Lynette Feder Joy Clay Sylvana M. Côté David P. Farrington Kate Freiberg Vicente Garrido Genovés Ross Homel Friedrich Lösel Matthew Manning Paul Mazerolle Rob Santos Martin Schmucker Christopher Sullivan Carole Sutton Tom van Yperen Richard E. Tremblay 《European Journal on Criminal Policy and Research》2007,13(3-4):327-356
22.
23.
Poppy seed ingestion as a contributing factor to opiate-positive urinalysis results: the Pacific perspective. 总被引:2,自引:0,他引:2
C M Selavka 《Journal of forensic sciences》1991,36(3):685-696
The possible contribution of poppy seed foods to positive opiate urinalysis results, especially from foods available in the Pacific Rim area, has recently become an issue for the U.S. Army Forensic Toxicology Drug Testing Laboratory in Hawaii. To assess the likelihood of this possible contribution, seven different poppy seed food products were consumed by male and female volunteers, and urine specimens were collected at time increments up to either 24 or 72 h. Specimens were evaluated for opiates using Roche Abuscreen radioimmunoassay (RIA), and all RIA positive specimens were analyzed for morphine and codeine using gas chromatography/mass spectrometry (GC-MS). Poppy seed cake, bagels, muffins, and rolls did not contain sufficient quantities of poppy seeds to give rise to opiate positive specimens by U.S. Department of Defense (DOD) GC-MS cutoff levels (morphine = 4000 ng/mL, codeine = 2000 ng/mL), although a number of specimens were positive by National Institute on Drug Abuse (NIDA) cutoff levels (morphine and codeine = 300 ng/mL). However, ingestion of poppy seed streusel or Danish pastry led to confirmed morphine and codeine positive specimens, irrespective of the use of DOD or NIDA confirmation cutoff values. In addition, significant amounts of codeine were observed in a number of these specimens. These findings argue against the unqualified application of previously published quantitative guidelines for eliminating poppy seed ingestion as a possible cause for a positive opiate urinalysis result. 相似文献
24.
Research has indicated that school factors such as communal school organization and student bonding are predictive of school disorder, with greater communal organization and greater student bonding leading to less delinquency and victimization. Data from a nationally representative sample of 254 public, nonalternative, secondary schools were used to examine structural equation models representing hypothesized relationships among communal school organization, student bonding, and school disorder. The hypothesis that communally organized schools would have less disorder held true for teacher victimization and student delinquency, but not for student victimization. In addition, the hypothesis that the relationship between communal school organization and school disorder would be mediated by student bonding was supported for student delinquency, but not for teacher victimization. 相似文献
25.
试析朝鲜反美主义情绪的来源和未来发展 总被引:2,自引:0,他引:2
当前朝鲜国内所存在的反美主义情绪已发展到相当高的程度,甚至已成为朝鲜政治生活中的一个重要主题.朝鲜的反美主义情绪对朝鲜的政治、经济和文化生活带来巨大的影响.同时朝鲜的反美主义情绪对朝鲜的对外关系带来重要的影响,可被看作朝美关系在冲突和缓和的循环中不断反复的一个重要原因,也给朝鲜半岛南北关系缓和及无核化进程带来种种变数.本文试图通过各种不同视角进行分析以把握朝鲜反美主义情绪的来源,进而分析朝鲜反美主义情绪在未来的发展和对美朝关系、朝鲜和周边国家关系以及对朝核问题的影响. 相似文献
26.
27.
28.
We investigated the differences in the levels of carboxyhemoglobin (COHb), cyanide (HCN) and petroleum fuels (gasoline and kerosene) between left and right ventricular bloods from fire victims. COHb was slightly, and HCN and petroleum fuels were markedly higher levels in the left than those in the right. These effects were so called 'first pass phenomena' due to the circulation, diffusion and metabolization before the deaths of fire victims. 相似文献
29.
30.
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