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   17677篇
  免费   333篇
各国政治   673篇
工人农民   1533篇
世界政治   722篇
外交国际关系   576篇
法律   10600篇
中国共产党   4篇
中国政治   77篇
政治理论   3746篇
综合类   79篇
  2023年   55篇
  2020年   134篇
  2019年   178篇
  2018年   1473篇
  2017年   1417篇
  2016年   1230篇
  2015年   258篇
  2014年   212篇
  2013年   1130篇
  2012年   450篇
  2011年   1161篇
  2010年   1188篇
  2009年   804篇
  2008年   1006篇
  2007年   927篇
  2006年   304篇
  2005年   322篇
  2004年   431篇
  2003年   378篇
  2002年   268篇
  2001年   292篇
  2000年   281篇
  1999年   204篇
  1998年   144篇
  1997年   142篇
  1996年   134篇
  1995年   131篇
  1994年   124篇
  1993年   117篇
  1992年   186篇
  1991年   203篇
  1990年   184篇
  1989年   181篇
  1988年   165篇
  1987年   180篇
  1986年   176篇
  1985年   166篇
  1984年   170篇
  1983年   174篇
  1982年   102篇
  1981年   93篇
  1980年   77篇
  1979年   112篇
  1978年   83篇
  1977年   84篇
  1976年   61篇
  1975年   59篇
  1974年   63篇
  1973年   74篇
  1972年   63篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
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   
103.
The authors examine the characteristics of threatening and otherwise inappropriate communications sent to members of the U.S. Congress by a sample of 86 subjects, 20 of whom threatened assassination. We quote excerpts from these letters and provide quantitative data on such variables as the volume, duration, form, and appearance of such communications; the enclosures; the subjects' perceived relationships to the recipients; the thematic content of the communications; and the messages and threats communicated. Comparisons between 43 subjects who pursued encounters with members of Congress and 43 who did not revealed 17 factors associated with such pursuit. In this population, threateners were significantly less likely to pursue an encounter than inappropriate letter writers who did not threaten, regardless of the type of threat or the harm threatened. Inappropriate letters to members of Congress are compared with those directed to Hollywood celebrities. Mentally disordered persons writing to public figures often mention and sometimes threaten public figures other than those to whom the letters are addressed, which raises important issues regarding notification of endangered third parties and the sharing of information among protective agencies.  相似文献   
104.
Despite its original purpose to protect and rehabilitate wayward children, the juvenile system has grown more punitive and has embraced the use of harsher punishments, including execution, for juvenile offenders. Relatively little is known, however, about public attitudes toward the use of capital punishment for juveniles. This research explored the determinants of death penalty opinion, identified the minimum age at which respondents were willing to allow a juvenile to be put to death and examined the willingness of respondents to support an alternative sentence of life without the possibility of parole (LWOP). The results suggested that, while one-quarter of the sample was willing to execute juveniles who were fifteen and under at the time of the crime, there was less support for the execution of juveniles than of adults. In addition, of those who supported the use of the death penalty for juveniles, almost one-half would support LWOP as an alternative to the death penalty.  相似文献   
105.
  With Asia's economy still booming in the second half of the 1990's “Asian values” were announced by some politicians (Lee Kuan Yew, Mahatir, Ishihara, Mahbubani etc.) and contrasted with “Western values”. Soon a controversial debate within Asia ensued (Kim, Fidel Ramos ea..), into which also the western democracies joined. The “West” however reacted rather defensively to the new assertiveness of some Asian statesmen, inspite of the fact that the authors of this debate put into question the western dominance in global value setting which has been in existence since the French revolution. But has this debate withstood the test of time, the challenges posed by the recession in Asia and by the ever increasing globalization? Hardly. The crisis has destroyed the notion that “Asian values” had been the main cause and guarantor of Asia's exorbitant growth rates. While in the West Christianity forms the essential basics of culture, in Asia there is a multitude of coexisting - and frequently confronting world religions. There is no other continent which in cultural and political terms is so contradictory and potentially conflict ridden like Asia. “Asianism” as a concept was surely also intended as an instrument to integrate multiethnic Asian societies with weak internal cohesion. At the same time it served to neutralize the human rights issue. In the meantime the debate has become quieter and more dispassionate. In the developed West the notion gained acceptance to abandon “Eurocentrism”. At the same time there is recognition that “Asian values” are not exclusive. Also in Europe the family plays a special role. A debate on values is needed for societal integration – also in the “West” which should become more aware of the need to reassert the origins of its own spiritual foundations. Following September 11th the west is well advised to continue the dialogue on values with Asia. Update and expanded version of an article first published in: Au?enpolitik IV/1996, p. 326 “Beginnt das pazifische Jahrhundert?” I would like to thank Julia Prati for the translation of the updated and expanded version of this article  相似文献   
106.
Recent studies point to the potential theoretical and practical benefits of focusing police resources on crime hot spots. However, many scholars have noted that such approaches risk displacing crime or disorder to other places where programs are not in place. Although much attention has been paid to the idea of displacement, methodological problems associated with measuring it have often been overlooked. We try to fill these gaps in measurement and understanding of displacement and the related phenomenon of diffusion of crime control benefits. Our main focus is on immediate spatial displacement or diffusion of crime to areas near the targeted sites of an intervention. Do focused crime prevention efforts at places simply result in a movement of offenders to areas nearby targeted sites—“do they simply move crime around the corner”? Or, conversely, will a crime prevention effort focusing on specific places lead to improvement in areas nearby—what has come to be termed a diffusion of crime control benefits? Our data are drawn from a controlled study of displacement and diffusion in Jersey City, New Jersey. Two sites with substantial street‐level crime and disorder were targeted and carefully monitored during an experimental period. Two neighboring areas were selected as “catchment areas” from which to assess immediate spatial displacement or diffusion. Intensive police interventions were applied to each target site but not to the catchment areas. More than 6,000 20‐minute social observations were conducted in the target and catchment areas. They were supplemented by interviews and ethnographic field observations. Our findings indicate that, at least for crime markets involving drugs and prostitution, crime does not simply move around the corner. Indeed, this study supports the position that the most likely outcome of such focused crime prevention efforts is a diffusion of crime control benefits to nearby areas.  相似文献   
107.
Fragment     
  相似文献   
108.
109.
Presents forensic medical characteristics of the specific features of stabbed and cut injuries of human skin and jersey. Suggests a complex of signs that will help determine some structural parameters of a knife blade and the conditions of its interaction with the injured site of human body.  相似文献   
110.
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   
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