全文获取类型
收费全文 | 18476篇 |
免费 | 1085篇 |
专业分类
各国政治 | 1035篇 |
工人农民 | 628篇 |
世界政治 | 1355篇 |
外交国际关系 | 601篇 |
法律 | 11632篇 |
中国政治 | 131篇 |
政治理论 | 4027篇 |
综合类 | 152篇 |
出版年
2021年 | 106篇 |
2020年 | 274篇 |
2019年 | 440篇 |
2018年 | 437篇 |
2017年 | 524篇 |
2016年 | 541篇 |
2015年 | 459篇 |
2014年 | 457篇 |
2013年 | 2096篇 |
2012年 | 432篇 |
2011年 | 503篇 |
2010年 | 486篇 |
2009年 | 491篇 |
2008年 | 479篇 |
2007年 | 448篇 |
2006年 | 451篇 |
2005年 | 407篇 |
2004年 | 419篇 |
2003年 | 400篇 |
2002年 | 376篇 |
2001年 | 688篇 |
2000年 | 601篇 |
1999年 | 495篇 |
1998年 | 255篇 |
1997年 | 194篇 |
1996年 | 214篇 |
1995年 | 221篇 |
1994年 | 228篇 |
1993年 | 226篇 |
1992年 | 372篇 |
1991年 | 383篇 |
1990年 | 363篇 |
1989年 | 387篇 |
1988年 | 340篇 |
1987年 | 345篇 |
1986年 | 374篇 |
1985年 | 375篇 |
1984年 | 326篇 |
1983年 | 317篇 |
1982年 | 226篇 |
1981年 | 206篇 |
1980年 | 169篇 |
1979年 | 246篇 |
1978年 | 154篇 |
1977年 | 168篇 |
1976年 | 138篇 |
1975年 | 115篇 |
1974年 | 143篇 |
1973年 | 132篇 |
1972年 | 112篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Dennis R. Fox 《Law and human behavior》1993,17(2):257-258
92.
93.
The concentration of thyreoglobulin (tg) was determined for death caused by hanging, strangulation by ligature, and throttling. Cases of sudden death (traumatic aortic rupture, penetrating wounds of the heart) were used for comparison. The mean values in cases of hanging (149.9±202.3 ng/ml), strangulation by ligature (193.1±173.3), manual strangulation (561.6±173.9) are distinguishable from violent acute deaths (23.3±27.6) and living healthy individuals (17.3±16.1). By means of statistical comparisons, significant differences were found between throttling and strangulation by ligature and between throttling and hanging (adjusted P<0.001). In connection with examination of the bodies high tg values can be regarded as a vital reaction in obstructive asphyxia. 相似文献
94.
A number of recent studies have explored the consequences ofinterracial peer effects on the academic and social performanceof minority students. This article contributes to that discussion,focusing, however, on perceptions rather than behaviors. Theanalysis suggests that exposure to white peers is associatedwith declining perceptions of racial justice among black andLatino high school students. While cautioning against causalinterpretations of this finding, the article suggests that theintegrationist aims of Brown v. Board of Education will notbe satisfied without more thoughtful and vigorous desegregationefforts. 相似文献
95.
96.
Conclusion The Regulations appear to have reinforced the protection available to software producers under United Kingdom law. The provisions of the Software Directive and the Regulations are complex and not without significant inconsistencies which are likely to prove to be a source of litigation. The drafters of the Regulations chose, unlike many of its European partners, not to adopt the wording of the Software Directive but to write their own interpretation, adding an element of uncertainty to the law in this area, which is perhaps inevitable bearing in mind the linguistic problems of translating and interpreting any directive coupled with the ambiguity and omission of definitions of several key terms. More important, however, than any academic argument will be the practical impact of the new law and its effectiveness in achieving its aim. 相似文献
97.
98.
Deoxyribonucleic acid (DNA) typing of ribosomal ribonucleic acid (rRNA) genes was performed with a polymerase chain reaction (PCR) assay for species identification. A variable region of the 28S ribosomal RNA gene was amplified with primers complementary to flanking sequences phylogenetically well conserved. The products of twelve animal DNAs (human, Japanese monkey, dog, cattle, pig, cat, rabbit, mouse, rat, chicken, frog, and fish) were separated by polyacrylamide gel electrophoresis, each revealing a few bands ranging from 150 to 100 base pairs. The band patterns obtained from each DNA sample differed in number and size, which indicates the applicability of the method to species identification. Samples containing either as little as 1 pg of DNA or degraded DNA of 0.2 to 0.5 kb in length were able to give detectable bands. Postmortem human tissue DNAs were tested as an example. They showed a pattern identical to the human control one, which was distinct from those of the other animals examined. 相似文献
99.
100.
A report of an international collaborative experiment to demonstrate the uniformity obtainable using DNA profiling techniques. 总被引:2,自引:0,他引:2
P Gill S Woodroffe W B?r B Brinkmann A Carracedo B Eriksen S Jones A D Kloosterman B Ludes B Mevag 《Forensic science international》1992,53(1):29-43
This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profile results could be achieved between different European laboratories. It was shown that this goal can be obtained provided that a common protocol is followed (specifically the use of a common electrophoretic buffer as being the most important parameter). Generally, lower molecular weight loci (with lower molecular weight fragments) such as YNH24 perform better than higher molecular weight loci such as MS43a. The results of the exercise are discussed in relation to the objectives of the European DNA profiling group (EDNAP). 相似文献