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   72450篇
  免费   3055篇
各国政治   4600篇
工人农民   2999篇
世界政治   6371篇
外交国际关系   3945篇
法律   34609篇
中国共产党   12篇
中国政治   804篇
政治理论   21201篇
综合类   964篇
  2021年   421篇
  2020年   1191篇
  2019年   1555篇
  2018年   1737篇
  2017年   2061篇
  2016年   2244篇
  2015年   1861篇
  2014年   2143篇
  2013年   10724篇
  2012年   1731篇
  2011年   1839篇
  2010年   1894篇
  2009年   2117篇
  2008年   1880篇
  2007年   1855篇
  2006年   1965篇
  2005年   1857篇
  2004年   1764篇
  2003年   1596篇
  2002年   1595篇
  2001年   1816篇
  2000年   1575篇
  1999年   1367篇
  1998年   1174篇
  1997年   1037篇
  1996年   998篇
  1995年   970篇
  1994年   990篇
  1993年   998篇
  1992年   1053篇
  1991年   1089篇
  1990年   1020篇
  1989年   1075篇
  1988年   1051篇
  1987年   1067篇
  1986年   1062篇
  1985年   1101篇
  1984年   988篇
  1983年   1051篇
  1982年   944篇
  1981年   891篇
  1980年   696篇
  1979年   747篇
  1978年   610篇
  1977年   563篇
  1976年   523篇
  1975年   440篇
  1974年   437篇
  1973年   440篇
  1972年   391篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
201.
202.
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   
203.
Kornai's thesis that shortage results from demand expansions bred by the soft budget constraint, derives from his implicit assumption that price regimes of input and output firms are different. Since any firm is both an input and an output firm, which discards the assumption as logically untenable, excess demand can only turn up because of lower than contracted inputs of labor and management that are not offset by an adequate downward adjustment of earnings. Expansions of demand that appear to be autonomous, are incited by uncertain deliveries of inputs, that is, by inefficiency (of output firms) as well. A by far the largest part of excess demand can be explained by state preferences for fast growth. As planners are more successful in generating investment, and the ensuing consumer, demand than in expanding production, shortage is inevitable regardless of the character of the firms' budget constraints.  相似文献   
204.
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   
205.
206.
207.
208.
The remains of an unidentified female neonate were discovered in a field in central Missouri. Examination revealed bilateral absence of the parietal bones. A search of the literature describing similar defects suggests that the present case represents a unique condition, described here for the first time.  相似文献   
209.
210.
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