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   2544篇
  免费   172篇
各国政治   199篇
工人农民   140篇
世界政治   241篇
外交国际关系   172篇
法律   1394篇
中国共产党   2篇
中国政治   16篇
政治理论   532篇
综合类   20篇
  2023年   38篇
  2022年   28篇
  2021年   44篇
  2020年   81篇
  2019年   103篇
  2018年   138篇
  2017年   161篇
  2016年   150篇
  2015年   111篇
  2014年   129篇
  2013年   369篇
  2012年   115篇
  2011年   92篇
  2010年   70篇
  2009年   60篇
  2008年   90篇
  2007年   111篇
  2006年   82篇
  2005年   97篇
  2004年   84篇
  2003年   85篇
  2002年   86篇
  2001年   46篇
  2000年   42篇
  1999年   34篇
  1998年   18篇
  1997年   18篇
  1996年   10篇
  1995年   17篇
  1994年   13篇
  1993年   5篇
  1992年   23篇
  1991年   15篇
  1990年   9篇
  1989年   14篇
  1988年   14篇
  1987年   13篇
  1986年   11篇
  1985年   11篇
  1983年   8篇
  1982年   6篇
  1980年   6篇
  1976年   4篇
  1975年   4篇
  1972年   5篇
  1969年   4篇
  1968年   4篇
  1967年   6篇
  1966年   4篇
  1964年   4篇
排序方式: 共有2716条查询结果,搜索用时 15 毫秒
151.
152.
153.
Nine Y-STR loci from the "minimal haplotype" included in Y-STR Haplotype Reference Databases (YHRD) together with eight additional Y-STRs (DYS437, DYS438, DYS439, DYS460, DYS461, GATA C4, GATA H4 and GATA A10) were analyzed in a sample of 101 males from Equatorial Guinea living in Madrid. Haplotype and allelic frequencies were calculated and genetic diversities were estimated for each genetic system as well as for the whole haplotype. An unexpected high frequency (6%) of intermediate alleles (13.2 and 14.2) was found in DYS385. For DYS19, two alleles were found in one sample. Another sample failed to amplify with DYS393 primers using either PowerPlex Y System (Promega Corporation) or the Y-PLEXtrade mark 12 (Reliagene, New Orleans, LA) commercial kits. Comparison between Equatorial Guinea and another African population (Mozambique; South East Coast) revealed a significant pairwise Phi(st) value between them (Phi(st)=0.03309; P=0.00000).  相似文献   
154.
The 11 Y-chromosomal short tandem repeats (STRs) included in the Promega Corporation PowerPlex Y System (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438 and DYS439) were typed in three ethnic groups ("Andalusians", Berber and Arab) and one cosmopolitan population (Tunis) from Tunisia, summing up 247 individuals, and 139 different haplotypes. Focusing the analysis on the seven Y-STRs of the YHRD Minimal Haplotype Core (DYS385 excepted), "Andalusians" showed no differences from the Cosmopolitan and the Arab samples previously published (our Arab sample presented an extremely low haplotype diversity), but were different from the Berbers. The Berbers from Tunisia were not different from those from Morocco.  相似文献   
155.
A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.  相似文献   
156.
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.  相似文献   
157.
Spamming is a major threat to the formation of public trust in the Internet and discourages broader civil participation in the emerging information society. To the individual, spams are usually little more than a nuisance, but collectively they expose Internet users to a panoply of new risks while threatening the communications and commercial infrastructure. Spamming also raises important questions of criminological interest. On the one hand it is an example of a pure cybercrime – a harmful behaviour mediated by the Internet that is the subject of criminal law, while on the other hand, it is a behaviour that has in practice been most effectively contained technologically by the manipulation of ‘code’ – but at what cost? Because there is not an agreed meaning as to what constitutes ‘online order’ that renders it simply and uncritically reducible to a set of formulae and algorithms that can be subsequently imposed (surreptitiously) by technological processes. The imposition of order online, as it is offline, needs to be subject to critical discussion and also checks and balances that have their origins in the authority of law. This article deconstructs and analyses spamming behaviour, before exploring the boundaries between law and code (technology) as governance in order to inform and stimulate the debate over the embedding of cybercrime prevention policy within the code itself.  相似文献   
158.
This study assessed the role of rape myth acceptance (RMA) and situational factors in the perception of three different rape scenarios (date rape, marital rape, and stranger rape). One hundred and eighty-two psychology undergraduates were asked to emit four judgements about each rape situation: victim responsibility, perpetrator responsibility, intensity of trauma, and likelihood to report the crime to the police. It was hypothesized that neither RMA nor situational factors alone can explain how rape is perceived; it is the interaction between these two factors that best account for social reactions to sexual aggression. The results generally supported the authors' hypothesis: Victim blame, estimation of trauma, and the likelihood of reporting the crime to the police were best explained by the interaction between observer characteristics, such as RMA, and situational clues. That is, the less stereotypic the rape situation was, the greater was the influence of attitudes toward rape on attributions.  相似文献   
159.
160.
This article examines the potential of trade measures to induce more climate-friendly policies, focusing on the relationship between global trade rules and the Kyoto climate regime. At the core of this interplay is the normative consistency of trade-related rules in the two regimes and any hierarchical relationship between them. The stronger clout of the WTO and its compulsory dispute settlement system suggest that issues involving competing claims would be referred to WTO bodies. Such bodies have so far been restrictive regarding the exceptions in WTO agreements to the general ban on embargoes and discrimination. The normative compatibility of the two regimes will also depend on their participatory interplay, specifically how they differentiate groups of actors as to rights and obligations. Non-members of WTO receive the least protection, and their vulnerability to climate-related trade measures is largely determined by their interdependence with states that consider employment of such measures. Among WTO members, the findings of a dispute settlement body would presumably differ depending on the status of the target under the Kyoto Protocol. A non-complier with Kyoto commitments would be more shielded than a non-party, because by joining the Kyoto regime a non-complier has exposed itself to regime-internal and less trade intrusive measures that should be exhausted first. A third dimension of interplay is linkage, or efforts to influence the regime interplay. To date there has only been moderate cross-agency coordination, but considerable attention is paid within each regime, including in the Millennium Round of trade negotiations, to the desirability of avoiding conflict between them.  相似文献   
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