首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   10512篇
  免费   307篇
各国政治   559篇
工人农民   314篇
世界政治   834篇
外交国际关系   467篇
法律   6121篇
中国共产党   1篇
中国政治   69篇
政治理论   2378篇
综合类   76篇
  2021年   66篇
  2020年   152篇
  2019年   171篇
  2018年   229篇
  2017年   275篇
  2016年   280篇
  2015年   185篇
  2014年   248篇
  2013年   1228篇
  2012年   256篇
  2011年   285篇
  2010年   243篇
  2009年   276篇
  2008年   335篇
  2007年   348篇
  2006年   323篇
  2005年   285篇
  2004年   290篇
  2003年   286篇
  2002年   256篇
  2001年   384篇
  2000年   354篇
  1999年   288篇
  1998年   145篇
  1997年   123篇
  1996年   121篇
  1995年   125篇
  1994年   123篇
  1993年   106篇
  1992年   170篇
  1991年   201篇
  1990年   162篇
  1989年   194篇
  1988年   166篇
  1987年   183篇
  1986年   184篇
  1985年   167篇
  1984年   142篇
  1983年   169篇
  1982年   123篇
  1981年   112篇
  1980年   96篇
  1979年   116篇
  1978年   96篇
  1977年   80篇
  1976年   73篇
  1975年   53篇
  1974年   77篇
  1973年   67篇
  1971年   55篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
The ENFSI (European Network of Forensic Science Institutes) DNA Working Group undertook a collaborative project on Y-STR typing of DNA mixture samples that were centrally prepared and thoroughly tested prior to the shipment. Four commercial Y-STR typing kits (Y-Filer, Applied Biosystems, Foster City, CA, USA; Argus Y Nonaplex, Biotype, Dresden, Germany; Powerplex Y, Promega, Madison, WI, USA; and DYSplex-3, SERAC, Bad Homburg, Germany) were used for the amplification of the mixture samples. The results of the study showed a striking inter-laboratory difference of kit performance as determined from the peak heights of the obtained Y-STR genotypes. Variation in quantity and quality of the shipped DNA can be excluded as reason for the observed differences because both samples and shipping conditions were found to be reproducible in an earlier study. The results suggest that in some cases a laboratory-specific optimization process is indicated to reach a comparable sensitivity for the analysis of minute amounts of DNA.  相似文献   
932.
No consensus yet exists on how to handle incidental findings (IFs) in human subjects research. Yet empirical studies document IFs in a wide range of research studies, where IFs are findings beyond the aims of the study that are of potential health or reproductive importance to the individual research participant. This paper reports recommendations of a two-year project group funded by NIH to study how to manage IFs in genetic and genomic research, as well as imaging research. We conclude that researchers have an obligation to address the possibility of discovering IFs in their protocol and communications with the IRB, and in their consent forms and communications with research participants. Researchers should establish a pathway for handling IFs and communicate that to the IRB and research participants. We recommend a pathway and categorize IFs into those that must be disclosed to research participants, those that may be disclosed, and those that should not be disclosed.  相似文献   
933.
Allele frequencies for 16 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA, and SE33) were calculated for a sample of 300 unrelated individuals from Greece. No deviations from Hardy–Weinberg equilibrium were observed for all loci. The combined power of discrimination (PD) and the combined power of exclusion (PE) for the 16 tested STR loci were 0.999999999 and 0.999999816, respectively. Population comparisons were carried out and low genetic distances were found between our data and those previously published for other neighbouring European populations.  相似文献   
934.
The financial crisis that currently threatens the stability of global capitalism is the latest in a long line of similar episodes stretching back some 200 years. While many orthodox economists explain the crisis in terms of the failure of the proper operation of the market mechanism, radical accounts see crisis as an aspect of the constitution of capital and of the process of the accumulation of capital itself. This article explores the extent to which Marx's understanding of accumulation and crisis can provide the basis for a general theory of capitalist crisis. It concludes that the growing and chronic separation between financial (fictitious) accumulation and productive accumulation is the key to understanding the latest crisis of capital expressed as a global credit crunch. Furthermore, Marx opens the door to the development of an overtly 'political' theory of crisis stressing the 'capitalist use of crisis' as a means for the violent reassertion of the fundamental class relation.  相似文献   
935.
Current forensic DNA profiling methods rely on the analysis of samples at specialised laboratories with an average turnaround time of several days. The ability to rapidly determine a partial profile of short tandem repeats at the point-of-arrest would be of great benefit to police forces around the world, for example enabling a suspect to be rapidly included or excluded from an investigation. We have developed a homogeneous PCR method for the interrogation of STR loci utilising fluorescent oligonucleotide probes and melting curve analysis. Alleles of the D18S51, TH01 and D8S1179 loci were differentiated and identified on the basis of target length and probe melting temperature. Assay performance was evaluated by comparing melting peak data with the AmpFlSTR® SGM Plus® system. The method is compatible with direct analysis of unpurified buccal swab samples, enabling a partial STR profile to be generated within 1 h.  相似文献   
936.
Following the Hinckley acquittal, 17 states and the federal government made changes to the insanity defense, including revising the standard, reassigning the burden of proof, and altering the standard of proof. Two studies were conducted to determine whether the specific insanity standard (including the assignment of burden of proof and standard of proof) employed had a significant effect on mock jurors' verdicts. Participants' comprehension of insanity defense instructions was measured and the factors jurors used to decide whether to find the defendant not guilty by reason of insanity (NGRI) were also assessed. Participants' comprehension of insanity defense standards was very low. When asked to identify the factors they considered important in determining whether to find a defendant NGRI, only three elements of insanity defense standards were identified as significant. The results may have important implications for policy decisions regarding the insanity defense.  相似文献   
937.
938.
Three programs in BASIC and SUPER BASIC language for personal computer are suggested. The first program makes it possible to calculate the degree of substance extraction and factor of its distribution between two liquid immiscible phases. The second program is designed to make calculations on distribution of substance in the organs of experimental animals. The third program is designed to determine specific and molar factors of light absorption. Results of calculations are presented as tables. Programs can be also used in mathematical processing of results obtained in the course of scientific research.  相似文献   
939.
940.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号