全文获取类型
收费全文 | 13367篇 |
免费 | 382篇 |
专业分类
各国政治 | 565篇 |
工人农民 | 441篇 |
世界政治 | 983篇 |
外交国际关系 | 443篇 |
法律 | 8472篇 |
中国政治 | 81篇 |
政治理论 | 2663篇 |
综合类 | 101篇 |
出版年
2020年 | 159篇 |
2019年 | 201篇 |
2018年 | 265篇 |
2017年 | 284篇 |
2016年 | 291篇 |
2015年 | 204篇 |
2014年 | 256篇 |
2013年 | 1326篇 |
2012年 | 300篇 |
2011年 | 335篇 |
2010年 | 297篇 |
2009年 | 299篇 |
2008年 | 332篇 |
2007年 | 357篇 |
2006年 | 387篇 |
2005年 | 317篇 |
2004年 | 312篇 |
2003年 | 336篇 |
2002年 | 306篇 |
2001年 | 501篇 |
2000年 | 441篇 |
1999年 | 364篇 |
1998年 | 177篇 |
1997年 | 153篇 |
1996年 | 139篇 |
1995年 | 139篇 |
1994年 | 145篇 |
1993年 | 141篇 |
1992年 | 246篇 |
1991年 | 288篇 |
1990年 | 259篇 |
1989年 | 283篇 |
1988年 | 256篇 |
1987年 | 294篇 |
1986年 | 267篇 |
1985年 | 291篇 |
1984年 | 246篇 |
1983年 | 270篇 |
1982年 | 189篇 |
1981年 | 179篇 |
1980年 | 150篇 |
1979年 | 178篇 |
1978年 | 146篇 |
1977年 | 120篇 |
1976年 | 117篇 |
1975年 | 106篇 |
1974年 | 121篇 |
1973年 | 120篇 |
1972年 | 93篇 |
1971年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
Report of an unusual finding of bones on the shore of the Baltic Sea. Although the morphological findings appeared similar to a human foot skeleton, a quick identification as sea dog bone was possible. 相似文献
54.
We report a case of rapid death from thrombotic thrombocytopaenic purpura (TTP) in a young pregnant lady who developed full blown symptoms soon after caesarean section. Extensive intramyocardial confluent haemorrhages and widespread microthrombi in heart, brain, adrenals and kidney were found at autopsy. Thrombotic thrombocytopaenic purpura is an uncommon condition, which carries a high fatality rate if untreated. Awareness of this syndrome together with its high risk of sudden death underlines the importance of rapid diagnosis and treatment. 相似文献
55.
C Moore S Browne I Tebbett A Negrusz W Meyer L Jain 《Forensic science international》1992,56(2):177-181
A new solid-phase extraction procedure for the determination of cocaine and benzoylecgonine in amniotic fluid, using high flow co-polymeric sorbents is reported. The recoveries of cocaine and benzoylecgonine within the range 0.1-1 mg/l were 95.7% and 50.3%, respectively. The use of high-flow sorbents allowed the easy extraction of amniotic fluid regardless of sample viscosity or physical nature. The use of these solid-phase columns provided many advantages over the more commonly used solvent extraction, including an increase in extraction speed and efficiency, reduced operator time, reduced solvent use and disposal volumes and exceptional extract quality. Further, the determination of amniotic fluid obtained from pregnant cocaine users may provide important information about handling of cocaine by the fetus at various gestational ages. The procedure was successfully applied to amniotic fluid from suspected cocaine abusers. 相似文献
56.
57.
The polymerase chain reaction (PCR) method of specific gene amplification was used in casework to synthesize millions of copies of the polymorphic second exon of the human leukocyte antigen (HLA)-DQ alpha (or DQA1) locus from a variety of evidence samples. The HLA-DQ alpha allelic variants in the amplified deoxyribonucleic acid (DNA) were determined in a rapid non-radioactive test by hybridization to sequence-specific oligonucleotide probes in both the dot-blot and reverse dot-blot formats. This genetic typing system has been subjected to blind proficiency testing; the performance of this test in the analysis of experimentally mixed samples was also evaluated. As of August 1990, over 250 cases have been tested and more than 2000 individual evidence (bloodstains, semen stains, individual hairs, bone fragments, and tissue sections) and reference samples have been analyzed. The first 198 of these cases are summarized in this paper; in 65% of the cases with conclusive results a suspect was included, and in 35%, all suspects were excluded. Individual cases as well as some of the general issues relating to forensic science analysis and this genetic typing system are discussed. The high rate of exclusion reported here combined with the ability of PCR to type old evidence samples suggests the relevance of this genetic test for postconviction review; two cases in which the convicted suspect was excluded are discussed. 相似文献
58.
59.
60.
A method ist described to determine the CO-content in the tissue of muscles. The prepared tissue is pulverized in a swinging mill at the temperature of liquid nitrogen. Parts of the powder are weighed into headspace vessels. Carbon monoxide ist ejected by a formerly described method and measured gaschromatographically. The Fe-content is determined after an acid disintegration by AAS. Acute intoxications lead to higher CO-contents in heart than in periphere muscles. Chronic exposure to carbon monoxide does not produce these differences. 相似文献