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   21293篇
  免费   673篇
  国内免费   5篇
各国政治   900篇
工人农民   917篇
世界政治   1523篇
外交国际关系   735篇
法律   13475篇
中国共产党   6篇
中国政治   191篇
政治理论   4039篇
综合类   185篇
  2021年   120篇
  2020年   285篇
  2019年   366篇
  2018年   454篇
  2017年   494篇
  2016年   510篇
  2015年   366篇
  2014年   411篇
  2013年   2025篇
  2012年   566篇
  2011年   600篇
  2010年   505篇
  2009年   530篇
  2008年   638篇
  2007年   673篇
  2006年   643篇
  2005年   585篇
  2004年   594篇
  2003年   589篇
  2002年   510篇
  2001年   894篇
  2000年   763篇
  1999年   617篇
  1998年   320篇
  1997年   236篇
  1996年   253篇
  1995年   228篇
  1994年   249篇
  1993年   243篇
  1992年   413篇
  1991年   464篇
  1990年   444篇
  1989年   392篇
  1988年   408篇
  1987年   378篇
  1986年   404篇
  1985年   363篇
  1984年   308篇
  1983年   289篇
  1982年   226篇
  1981年   258篇
  1980年   160篇
  1979年   243篇
  1978年   162篇
  1977年   130篇
  1976年   118篇
  1975年   155篇
  1974年   169篇
  1973年   145篇
  1972年   132篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
This paper reports results of a study based on a nationally representative sample of U.S. youth (N = 11,549) that asked two questions: (1) How does family structure affect the likelihood of adolescent death beyond that of race/ethnicity, sex, socioeconomic status, personal behavior, and other structural factors and (2) under what conditions might appeals for social justice be warranted for relative mortality statuses and for absolute gains in mortality? The study found that marital instability increases the likelihood of dying when controlling for a variety of other factors including class, race/ethnicity, sex, and unemployment rate in area of residence. The author argues that this finding lends support to social justice arguments to redistribute resources in such a way as to ensure the likelihood of absolute gains in mortality. The study also found, however, that race/ethnicity/sex also accounted for the likelihood of dying independently of family structure when controlling for socioeconomic and other factors. The author argues that this finding lends support to social justice arguments to redistribute resources on the basis of relative mortality statuses.  相似文献   
34.
Fibres used in forensic casework suffer from a disadvantage common to other forms of trace evidence--it is not possible to state with absolute certainty that they originate from a specific source. Target fibre studies, population studies and research on 'blocks of colour' have effectively demonstrated the polymorphism of textile fibres (particularly man-made ones) and have shown that when a fibre is believed to have a specific putative source, the chance that it has originated from a different source purely by coincidence is extremely remote. A study by Houck MM (Houck MM, Inter-comparison of unrelated fibre evidence. Forensic Science International 2003; 135: 146-149) has shown that no coincidental matching fibres were recovered from items of clothing examined in 20 unrelated crimes. The study involved over two million comparisons. This work goes a step further, and using the example of blue polyester fibres shows that even within a very narrow segment of the whole general fibre population, many examples of a specific colour/type of man-made fibre taken from random sources can be compared and the chance of any two being the same is very low. These studies should help to show the specificity and value of transferred fibres in providing forensic evidence.  相似文献   
35.
This article summarizes some of the literature reviewed by the Girls Study Group, which is a federally funded project aimed at assessing the causes of girls’ delinquency as well as evaluating programs to address it. The literature reveals that a number of factors such as family dysfunction, involvement with antisocial peers, and living in disadvantaged neighborhoods are correlated with delinquency for both boys and girls. Some factors, however, are gender sensitive, meaning that either girls are more exposed to a given risk factor than boys or react somewhat differently to a given risk factor. Girls have higher rates of exposure to sexual assault, which is associated with delinquency and, although more research is needed, they are more affected by the impacts of early puberty, when it is coupled with harsh parenting and disadvantaged neighborhoods. This article discusses some implications of the research on correlates of delinquency for programming for girls and makes recommendations for program selection.  相似文献   
36.
The American Law Institute proposes that in contested physical custody cases the court should allocate to each parent a proportion of the child's time that approximates the proportion of time each has spent performing caretaking functions in the past. Examined through the lens of child development research, the approximation rule is unlikely to improve on the best interests standard. It is difficult to apply; is perceived as gender‐biased; creates a new focus for disputing parents; renders a poor estimate of parents’ contributions to their child's best interests; overlooks parents’ intangible, yet significant, contributions to their child's well‐being; and miscalculates the essence of how a child experiences the family. A preferable alternative is a better defined, contemporary best interests standard that accommodates new knowledge and reforms that encourage nonadversarial, individualized resolutions of custody disputes.  相似文献   
37.
38.
Having found that a deep hyperlink on Davis' website to livestreaming of a motorcycle race owned by Live Nation constitutescopying, the court granted Live Nation's Motion for summaryjudgment in its copyright infringement claim and enjoined Davisfrom maintaining the link.  相似文献   
39.
40.
A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80–90%. The reproducibility of the results was always >90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.  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