全文获取类型
收费全文 | 10625篇 |
免费 | 324篇 |
国内免费 | 11篇 |
专业分类
各国政治 | 640篇 |
工人农民 | 371篇 |
世界政治 | 739篇 |
外交国际关系 | 549篇 |
法律 | 5610篇 |
中国共产党 | 179篇 |
中国政治 | 534篇 |
政治理论 | 1929篇 |
综合类 | 409篇 |
出版年
2021年 | 57篇 |
2020年 | 145篇 |
2019年 | 144篇 |
2018年 | 200篇 |
2017年 | 241篇 |
2016年 | 236篇 |
2015年 | 231篇 |
2014年 | 260篇 |
2013年 | 1183篇 |
2012年 | 350篇 |
2011年 | 414篇 |
2010年 | 359篇 |
2009年 | 376篇 |
2008年 | 373篇 |
2007年 | 366篇 |
2006年 | 386篇 |
2005年 | 357篇 |
2004年 | 261篇 |
2003年 | 299篇 |
2002年 | 218篇 |
2001年 | 400篇 |
2000年 | 347篇 |
1999年 | 299篇 |
1998年 | 155篇 |
1997年 | 106篇 |
1996年 | 115篇 |
1995年 | 101篇 |
1994年 | 111篇 |
1993年 | 102篇 |
1992年 | 163篇 |
1991年 | 158篇 |
1990年 | 147篇 |
1989年 | 138篇 |
1988年 | 159篇 |
1987年 | 157篇 |
1986年 | 160篇 |
1985年 | 146篇 |
1984年 | 145篇 |
1983年 | 154篇 |
1982年 | 92篇 |
1981年 | 67篇 |
1980年 | 80篇 |
1979年 | 98篇 |
1978年 | 78篇 |
1977年 | 66篇 |
1976年 | 68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 15 毫秒
931.
932.
933.
934.
This paper is a starting point for a research project which will try to develop practical methods for analyzing changes in gender relations to inform policy research in improving the storage, processing, and marketing of crops in sub-Saharan Africa. While the research project will focus upon the crop post-harvest sector, many concerns raised in this study are relevant to a wide range of development interventions. This paper is based upon existing literature and offers no new empirical findings. Major conceptual advances in thinking about gender relations suggest the need to reassess conventional gender analyses in the context of development interventions. Evidence from development practice supports the argument that targeting can be undermined by processes of gendered bargaining around project interventions. Academic research points to key problems and potential methods for viewing changes in gender relations which may be adapted to project contexts. Existing gender planning frameworks focus upon shifts in gender relations, but also need to address the process by which gender relations are renegotiated if they are to inform better planning, monitoring, and evaluation. 相似文献
935.
A study was undertaken to develop demographic, toxicologic, and pathological profiles of methamphetamine-related deaths. Anatomic and toxicologic findings in 413 deaths where methamphetamine was detected were compared with findings in a control group of 114 drug-free trauma victims. The number of cases per year did not change significantly over the course of the study. Mean age was 36.8 years, but 11% were over the age of 50. Decedents were overwhelmingly male (85.2%) and Caucasian (75%). Blood concentrations of methamphetamine and amphetamine were indistinguishable in cases where methamphetamine was related to the cause of death (MR) and cases where it was not (non-MR) (2.08 vs. 1.78 mg/L, p = 0.65, and 0.217 vs. 0.19 mg/L, p = 0.82). Coronary artery disease, ranging from minimal to severe multivessel, was identified in 79 of the 413 drug users, but in only six of the 114 drug-free controls (p = 0.0004), and MR decedents had enlarged hearts compared with controls. There were also ten cases of subarachnoid and intracranial hemorrhage in the MR group. Abnormalities of the liver (34%) and lungs (24.7%) were frequent. In 65% of these cases, death was due to accidental methamphetamine toxicity. In the remaining cases, methamphetamine was an incidental finding. We conclude that, in our jurisdiction, neither the rate of detection nor the number of methamphetamine deaths has increased significantly in the past 13 years. Decedents are almost all Caucasian males, and many were approaching middle-age. Methamphetamine use is strongly associated with coronary artery disease and with subarachnoid hemorrhage. 相似文献
936.
Tomsey CS Basten CJ Budowle B Giles BA Ermlick S Gotwald S 《Journal of forensic sciences》1999,44(2):385-388
Statistical analysis was performed on a subset of the Pennsylvania State Police Caucasian, African American and Hispanic database for the purpose of determining Hardy-Weinberg equilibrium and associations across the RFLP loci D1S7, D2S44, D4S139, D5S110, D10S28 and D17S79 and the PCR-based loci HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and Gc. Overall, the statistical results are consistent with a population in equilibrium both within and between loci. The assumption for independence is valid. 相似文献
937.
Baldauf C 《Archiv für Kriminologie》1999,204(3-4):93-105
The paper reflects the current state of the art in forensic linguistics and discusses the fundamental problem of the determination of the significance of linguistic features that are the basis of linguistic reports. A method is proposed that supplements the computer-assisted method of the BKA. 相似文献
938.
939.
This article describes the application of solid-phase microextraction (SPME) to the recovery of manufacturing by-products and impurities from an illicit drug seizure. The preparation chosen for examination using this technique contained 4-methoxyamphetamine, an hallucinogenic amphetamine that has been encountered frequently in South Australia. Compounds found in the PMA preparation included 4-methoxyphenol, 4-methoxybenzaldehyde, 4-methoxyphenyl-2-propanone, 4-methoxyphenyl-2-propanol, 4-methoxyphenyl-propene, and (tentatively) 4-methyl-5-(4'-methoxyphenyl) pyrimidine. The presence of these compounds suggests that the active drug was prepared from 4-methoxybenzaldehyde via 4-methoxyphenyl-2-propanone using a Leuckardt reductive amination. In this instance, SPME was found to be a simple, rapid, and non-destructive recovery technique that gave results complementary to those provided by conventional liquid-liquid extraction. There is an indication that SPME might find application in profiling of illicit drugs. 相似文献
940.
Tahir MA Rogers C Alkhayyat M el-Gohary M Budowle B Balamurugan K 《Journal of forensic sciences》1999,44(6):1314-1315
This study demonstrates that the locus D1S80 is highly polymorphic in the Bahrainian population. There were 24 different D1S80 alleles and 51 distinct genotypes observed in 198 Bahrainians. There was one allele observed that was smaller than the 14 repeat allele. This data set meets the Hardy-Weinberg expectations (HWE) and could be a useful marker for parentage testing and forensic applications. 相似文献