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   10626篇
  免费   551篇
各国政治   423篇
工人农民   377篇
世界政治   838篇
外交国际关系   312篇
法律   7137篇
中国共产党   1篇
中国政治   54篇
政治理论   1994篇
综合类   41篇
  2021年   63篇
  2020年   196篇
  2019年   239篇
  2018年   236篇
  2017年   297篇
  2016年   304篇
  2015年   249篇
  2014年   276篇
  2013年   1015篇
  2012年   238篇
  2011年   308篇
  2010年   289篇
  2009年   301篇
  2008年   291篇
  2007年   260篇
  2006年   278篇
  2005年   251篇
  2004年   255篇
  2003年   236篇
  2002年   243篇
  2001年   466篇
  2000年   424篇
  1999年   291篇
  1998年   184篇
  1997年   150篇
  1996年   125篇
  1995年   119篇
  1994年   146篇
  1993年   132篇
  1992年   197篇
  1991年   219篇
  1990年   204篇
  1989年   213篇
  1988年   206篇
  1987年   190篇
  1986年   233篇
  1985年   206篇
  1984年   161篇
  1983年   169篇
  1982年   115篇
  1981年   121篇
  1980年   85篇
  1979年   133篇
  1978年   75篇
  1977年   73篇
  1976年   70篇
  1974年   75篇
  1973年   66篇
  1972年   66篇
  1970年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Family courts and child welfare agencies across the country are charged with protecting the safety of our children. That mission has become more challenging with increasing federal legislation and decreasing funding. In Buffalo, N.Y., the Family Court and the Department of Social Services have teamed up to respond to this challenge. With minimal additional staffing and resources, they have led a collaboration of agencies and service providers to change the way business is done in child welfare. By engaging each other in an interagency system change effort, the amount of time children spend in foster care has been reduced. The collaboration has been able to accomplish in a relatively short time what no agency had previously been able to accomplish on its own. The beneficiaries have been the children and families of Erie County.  相似文献   
22.
In the wake of the 1990 amendments to the Clean Air Act, localities across the United States initiated public information campaigns both to raise awareness of threats to air quality and to change behavior related to air pollution by recommending specific behavioral changes in the campaign messages. These campaigns are designed to reduce the health hazards associated with poor air quality and to avoid federal sanctions resulting from the failure to meet air quality standards. As in many other communities across the country, a coalition of government agencies and businesses initiated a public information campaign in the Atlanta metropolitan region to reduce certain targeted behaviors, mainly driving. A two‐stage model used to analyze data from a rolling sample survey shows that the centerpiece of the information campaign—air quality alerts—was effective in raising awareness and reducing driving in a segment of the population. When the overall information campaign was moderated by employers' participation in programs to improve air quality, drivers significantly reduced the number of miles they drove and the number of trips they took by car on days when air quality alerts were sounded. Public information campaigns can be successful in increasing awareness, but changing well‐established behaviors, such as driving, is likely to require institutional mediation to provide social contexts that support the behavioral change, as well. © 2003 by the Association for Public Policy Analysis and Management.  相似文献   
23.
We report a case of rapid death from thrombotic thrombocytopaenic purpura (TTP) in a young pregnant lady who developed full blown symptoms soon after caesarean section. Extensive intramyocardial confluent haemorrhages and widespread microthrombi in heart, brain, adrenals and kidney were found at autopsy. Thrombotic thrombocytopaenic purpura is an uncommon condition, which carries a high fatality rate if untreated. Awareness of this syndrome together with its high risk of sudden death underlines the importance of rapid diagnosis and treatment.  相似文献   
24.
A new solid-phase extraction procedure for the determination of cocaine and benzoylecgonine in amniotic fluid, using high flow co-polymeric sorbents is reported. The recoveries of cocaine and benzoylecgonine within the range 0.1-1 mg/l were 95.7% and 50.3%, respectively. The use of high-flow sorbents allowed the easy extraction of amniotic fluid regardless of sample viscosity or physical nature. The use of these solid-phase columns provided many advantages over the more commonly used solvent extraction, including an increase in extraction speed and efficiency, reduced operator time, reduced solvent use and disposal volumes and exceptional extract quality. Further, the determination of amniotic fluid obtained from pregnant cocaine users may provide important information about handling of cocaine by the fetus at various gestational ages. The procedure was successfully applied to amniotic fluid from suspected cocaine abusers.  相似文献   
25.
The polymerase chain reaction (PCR) method of specific gene amplification was used in casework to synthesize millions of copies of the polymorphic second exon of the human leukocyte antigen (HLA)-DQ alpha (or DQA1) locus from a variety of evidence samples. The HLA-DQ alpha allelic variants in the amplified deoxyribonucleic acid (DNA) were determined in a rapid non-radioactive test by hybridization to sequence-specific oligonucleotide probes in both the dot-blot and reverse dot-blot formats. This genetic typing system has been subjected to blind proficiency testing; the performance of this test in the analysis of experimentally mixed samples was also evaluated. As of August 1990, over 250 cases have been tested and more than 2000 individual evidence (bloodstains, semen stains, individual hairs, bone fragments, and tissue sections) and reference samples have been analyzed. The first 198 of these cases are summarized in this paper; in 65% of the cases with conclusive results a suspect was included, and in 35%, all suspects were excluded. Individual cases as well as some of the general issues relating to forensic science analysis and this genetic typing system are discussed. The high rate of exclusion reported here combined with the ability of PCR to type old evidence samples suggests the relevance of this genetic test for postconviction review; two cases in which the convicted suspect was excluded are discussed.  相似文献   
26.
The primary aim of this paper is to review the literature on preadolescent friendships in order to examine the relationship between preadolescent friendships and social support in adulthood. Social supports are important to health, both directly and as a stress buffer. Few studies, however, have specifically examined adult social supports from the perspective of their developmental precursors and critical developmental periods. Some data indicate that the preadolescent period may be of particular importance to the development of adult social skills and ties. Observational and empirical studies of preadolescent peer relationships, and in particular best friendships, suggest unique and critical contributions to adult social relatedness. Present research is suggestive but is insufficient to validate preadolescence as a critical period in adult social relatedness. Our review has implications for better understanding the mechanisms by which preadolescent friendships effect adult social support—an important mediator of the effects of stress on health. Further longitudinal study is needed.Received Ph.D. from University of Maryland. Research interests are social supports and psychological responses to trauma and disaster.Received M.D. from Yale University. Research interests are social supports and traumatic stress.  相似文献   
27.
Presented in this paper are the initial results involving the use of the nose or outer ear as temperature measurement sites to determine the postmortem period of the human corpse. Simple mathematical models for both sites are developed based on cooling curves of five corpses. Analysis of errors between actual and calculated postmortem intervals suggest that in its present form, the described methods would not be suitable for use in accurately determining the time since death of human corpses.  相似文献   
28.
A dissecting intramural haematoma of the coronary artery is an infrequent cause of sudden and unexpected death. Most cases are women and in a significant number of these women, the haematoma occurred at term to 80 days postpartum. Because the intimal rupture and communication with the lumen were not found in most of the cases, the site of rupture has been considered to be a vasa vasorum. The authors report on a case of one woman who was at a later postpartum period (106 days). The microscopic finding of the dissected coronary artery revealed two intimal tears in a section. The case showed that the dissecting intramural haematoma of the coronary artery is caused not only by the rupture of the vasa vasorum but also by the rupture of the intima.  相似文献   
29.
A final course, or project is a standard requirement in Master of Public Administration (MPA) programs. This requirement is intended to permit the student to demonstrate advanced ability in the discipline. This article examines one such course at Florida State University. The course included readings, exercises, oral presentations, and a written report. This author assesses the merits and drawbacks of the course as well as notes the unintended consequences that resulted. In concluding the article, the author makes several recommendations for future courses based on the experiences gained in the Florida state model.  相似文献   
30.
Abstract
The author presents a relatively formal theory of the rule of law which includes three basic components: conceptual, institutional and axiological. He then emphasizes the differences between a formal and a substantive theory of the rule of law and highlights the advantages and limits of the former. Finally, the author indicates the importance of this type of theory, namely the values it implies such as predictability, justified reliance, autonomous choice, minimization of disputes and legitimacy.**  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