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   24468篇
  免费   1421篇
各国政治   1031篇
工人农民   1095篇
世界政治   1755篇
外交国际关系   847篇
法律   16590篇
中国共产党   2篇
中国政治   148篇
政治理论   4281篇
综合类   140篇
  2023年   120篇
  2021年   143篇
  2020年   529篇
  2019年   589篇
  2018年   750篇
  2017年   806篇
  2016年   883篇
  2015年   633篇
  2014年   728篇
  2013年   2602篇
  2012年   690篇
  2011年   724篇
  2010年   689篇
  2009年   703篇
  2008年   712篇
  2007年   748篇
  2006年   735篇
  2005年   588篇
  2004年   618篇
  2003年   549篇
  2002年   556篇
  2001年   904篇
  2000年   827篇
  1999年   657篇
  1998年   324篇
  1997年   238篇
  1996年   267篇
  1995年   257篇
  1994年   238篇
  1993年   237篇
  1992年   430篇
  1991年   435篇
  1990年   406篇
  1989年   403篇
  1988年   417篇
  1987年   389篇
  1986年   431篇
  1985年   436篇
  1984年   346篇
  1983年   340篇
  1982年   261篇
  1981年   234篇
  1980年   200篇
  1979年   295篇
  1978年   176篇
  1977年   148篇
  1976年   127篇
  1975年   132篇
  1974年   180篇
  1973年   135篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
The Rehabilitation Engineering Research Center on Technology Transfer (T2RERC) hosted a “State of the Science” conference in November, 2001. The conference reviewed technology transfer work within the field of assistive technology, and summarized related work in public, private and academic sectors. Invited speakers prepared papers on various topics concerning technology transfer, and related their findings to the field of assistive technology during the ensuing discussion sessions. This paper provides an overview of the material presented by the participants, and explores the implications of their findings for one particular field of application—assistive technology for people with disabilities.  相似文献   
62.
In their article, Tippins and Wittmann articulate a strong position against custody evaluators making specific custody recommendations to the court. This response will focus on my thoughts about their concepts and my belief that recommendations can be useful and appropriate some of the time, even though there may be significant problems with certain types of recommendations and problems with some evaluators.  相似文献   
63.
In recent years, legislators in all fifty states have given grandparents rights to petition for visitation privileges with grandchildren that can be enforced over parental objections. Grandparent visitation rights reflect an effort to protect meaningful relationships children enjoy with nonparental caregivers, enlist the assistance of extended family when the child's nuclear family is disrupted, and defend the interests of grandparents themselves. This psycholegal analysis explores the direct and indirect consequences of grandparent visitation statutes for family functioning. Statutory provisions are summarized, and the effects of these statutes are evaluated in light of what is known about the role of grandparents in child development, how courts evaluate children's "best interests" in grandparent visitation disputes, and how these statutes can alter family functioning in informal ways. The authors conclude that there are risks as well as benefits to children and families in grandparent visitation statutes, and suggest directions for procedural and statutory reform.  相似文献   
64.
A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 μl of the solution containing 0.5 μg chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.  相似文献   
65.
Although there has been speculation regarding the pervasiveness and nature of judicial decisions regarding life-sustaining medical treatment (LSMT), no attempt has been made to empirically assess their prevalence or the issues they address. An exploratory study utilizing a mail survey of a nationwide random sample (N = 905) of state trial court judges was conducted to provide initial information regarding this decision-making process. Twenty-two percent of the responding judges had heard at least one LSMT case, and judicial review did not appear endemic to particular states. The number of judges hearing LSMT cases dropped from 1975 to 1981 but has increased since then. Three major issues predominate: patient competency, appointment of a surrogate decisionmaker, and resolution of the ultimate issue of forgoing LSMT. Relatively few cases either contested a prior directive's validity or involved imposing sanctions for instituting or forgoing LSMT. Although subject to different interpretations, the results suggest the courts are having a significant impact on certain aspects of the LSMT decision-making process. However, the infrequency with which any one judge is called upon to make an LSMT decision causes concern about the judiciary's ability to respond in a timely and appropriate manner. With their potential for a profound effect on the actions of health care providers, greater attention to this decision-making process is warranted.  相似文献   
66.
The possible contribution of poppy seed foods to positive opiate urinalysis results, especially from foods available in the Pacific Rim area, has recently become an issue for the U.S. Army Forensic Toxicology Drug Testing Laboratory in Hawaii. To assess the likelihood of this possible contribution, seven different poppy seed food products were consumed by male and female volunteers, and urine specimens were collected at time increments up to either 24 or 72 h. Specimens were evaluated for opiates using Roche Abuscreen radioimmunoassay (RIA), and all RIA positive specimens were analyzed for morphine and codeine using gas chromatography/mass spectrometry (GC-MS). Poppy seed cake, bagels, muffins, and rolls did not contain sufficient quantities of poppy seeds to give rise to opiate positive specimens by U.S. Department of Defense (DOD) GC-MS cutoff levels (morphine = 4000 ng/mL, codeine = 2000 ng/mL), although a number of specimens were positive by National Institute on Drug Abuse (NIDA) cutoff levels (morphine and codeine = 300 ng/mL). However, ingestion of poppy seed streusel or Danish pastry led to confirmed morphine and codeine positive specimens, irrespective of the use of DOD or NIDA confirmation cutoff values. In addition, significant amounts of codeine were observed in a number of these specimens. These findings argue against the unqualified application of previously published quantitative guidelines for eliminating poppy seed ingestion as a possible cause for a positive opiate urinalysis result.  相似文献   
67.
本文是2006年5月25日在香港大学召开的"中非人力资源开发与合作"学术研讨会的系列论文之一。作者基于贫困的持续性与其各构成要素的相互关联性这一机理,运用比较研究方法,测度和评析尼日利亚与中国的减贫政策及其实施效应,反映了国际学术界对减贫问题的研究动态。诚然,本文仅代表作者的观点。  相似文献   
68.
The main aim of this paper is to advance knowledge and (especially) theories about developmental and life‐course criminology (DLC). First, I review the widely accepted DLC findings that all DLC theories have been designed to explain. Second, I review more contentious and unresolved empirical DLC issues that might present challenges to DLC theories. Third, I describe my own DLC theory and specify how it addresses key empirical and theoretical questions. Fourth, I summarize five important DLC theories, by Catalano and Hawkins, Sampson and Laub, Moffitt, LeBlanc, and Thornberry and Krohn. Fifth, I identify differences in assumptions and predictions between my theory and the other five theories. Finally, I recommend a detailed comparison of the key features of all DLC theories, of their answers to key empirical and theoretical questions, and of their predictions regarding key unresolved empirical DLC issues.  相似文献   
69.
70.
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