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   17403篇
  免费   608篇
  国内免费   5篇
各国政治   736篇
工人农民   770篇
世界政治   1161篇
外交国际关系   638篇
法律   11115篇
中国共产党   6篇
中国政治   162篇
政治理论   3248篇
综合类   180篇
  2021年   101篇
  2020年   252篇
  2019年   309篇
  2018年   374篇
  2017年   442篇
  2016年   453篇
  2015年   330篇
  2014年   357篇
  2013年   1638篇
  2012年   502篇
  2011年   522篇
  2010年   425篇
  2009年   440篇
  2008年   534篇
  2007年   589篇
  2006年   552篇
  2005年   513篇
  2004年   486篇
  2003年   518篇
  2002年   452篇
  2001年   676篇
  2000年   554篇
  1999年   497篇
  1998年   257篇
  1997年   174篇
  1996年   207篇
  1995年   184篇
  1994年   204篇
  1993年   197篇
  1992年   336篇
  1991年   360篇
  1990年   345篇
  1989年   292篇
  1988年   324篇
  1987年   279篇
  1986年   322篇
  1985年   285篇
  1984年   231篇
  1983年   225篇
  1982年   180篇
  1981年   192篇
  1980年   130篇
  1979年   171篇
  1978年   123篇
  1977年   107篇
  1975年   127篇
  1974年   134篇
  1973年   104篇
  1972年   101篇
  1969年   101篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
The impact of high temperatures (24 to 39 degrees C) and low to moderately high humidities (20 to 70%) on the applicability of TLC systems for drug identification was studied during a 6 month climatologic cycle in Burkina Faso (West Africa). In general, the Rf values as observed on the plates were found to be substantially affected as compared with values obtained at temperate climates. Some TLC systems were more affected than others and the largest deviations of up to 30 Rf units were at low humidities. Tropical conditions also had a negative effect on the reproducibility of Rf values. However, when an Rf-correction procedure was applied, using reference mixtures of known drugs on each plate, accuracy as well as reproducibility of the resulting Rfc values were drastically improved and data thus corrected were found to be compatible with existing TLC data bases developed under moderate climatological conditions. The impact of high to extremely high humidities (70 to 100%) remains to be investigated.  相似文献   
142.
测定了痢疾杆菌福氏 2a 30 1株与喹喏酮类药物耐药性相关的 gyrA基因和 parC基因的序列 ,并对其环丙沙星耐药诱变株的 gyrA和 parC基因喹喏酮类药物耐药性决定区 (QRDR)序列进行了测定分析。结果表明 ,痢疾杆菌福氏 2a 30 1株 gyrA和 parC基因分别为 2 6 2 5bp和2 2 5 6bp ,环丙沙星诱导的耐药菌 gyrA基因QRDR(2 4 5bp)发生氨基酸残基 6 9 Ala→Val和 87 Tyr→Asp改变 ,parC基因QRDR(2 37b)发生氨基酸残基 79 Ala→Asp、84 Ala→Glu和 85 Pro→Ala改变。这一研究结果对认识痢疾杆菌喹喏酮类药物耐药性的分子机理具有重要意义  相似文献   
143.
In this study, a new method was developed for the impurity profiling of illicit MDMA tablets. The extraction efficiency, linearity, repeatability and reproducibility of the method were evaluated. Eighty two MDMA tablets coming from presumed unrelated large seizures in 2004 (n >500 tablets) were analyzed by gas chromatography mass spectrometry (GC-MS) in order to assess the discrimination power of the method. The latter was found to be practical, robust, relatively easy to perform, highly discriminative and yielding good chromatography. In addition, some new impurities were detected and identified. Their chemical structures and mass spectra are reported.  相似文献   
144.
145.
The role of the state is changing under the impact of, for example, globalization. The changes have been variously understood as the new public management (NPM), the hollowing–out of the state and the new governance. This special issue of Public Administration explores the changing role of the state in advanced industrial democracies. It focuses on the puzzle of why states respond differently to common trends.
This introductory article has three aims. First, we provide a brief review of the existing literature on public sector reform to show that our approach is distinctive. We argue that the existing literature does not explore the ways in which governmental traditions shape reform. Second, we outline an interpretive approach to the analysis of public sector reform built on the notions of beliefs, traditions, dilemmas and narratives. We provide brief illustrations of these ideas drawn from the individual country articles. Finally, we outline the ground covered by all the chapters but we do not summarize and compare their experiences of reform. That task is reserved for the concluding article.  相似文献   
146.
This synoptic article focuses on the origin and functioning of the Office of the Family Advocate as the protector of the interests of minor children in divorce cases. Attention is paid to the general contemporary trend to specialise in judicial decision-making that developed out of an increasing need for expertise in the administration of justice. A number of arguments for and against judicial specialisation are addressed. The origin of the Office of the Family Advocate within the South African judicial system is discussed and a brief exposition of the history of divorce legislation in South Africa is given. This is followed by attention to the functioning of the Office of the Family Advocate with reference to the process followed in investigations of this office and points of criticism against the system are highlighted. The article closes with an indication of the need for research in this regard and possible focus points for future research are identified.  相似文献   
147.
In a case of suicidal application of electricity differences between the rectal temperature of the body and the suspected time of death were observed.In order to answer the question whether an electric current from hand to hand over >30 min led to a rise in body temperature FEM-based computer simulations and animal experiments were carried out. Both resulted in a warming of the soft parts in the arm without warming the body core. Thus a temperature-based estimation of the time since death can also be used in cases with electricity as the cause of death. Besides, in the animal experiment we found a spontaneous rise in the body core temperature even without application of electricity which may be a reason for the typical temperature plateau after death.  相似文献   
148.
149.
150.
Forecasters often disagree on revenue predictions because of differing techniques. Some states, such as Utah, have turned to the use of survey research methods to avoid this dilemma. This article reviews many of the national forecasting models examining consumer sentiment currently in use. And it compares the Utah experience with surveys used in other states.  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