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   11797篇
  免费   666篇
各国政治   514篇
工人农民   407篇
世界政治   957篇
外交国际关系   434篇
法律   7638篇
中国共产党   2篇
中国政治   69篇
政治理论   2380篇
综合类   62篇
  2023年   52篇
  2021年   73篇
  2020年   231篇
  2019年   285篇
  2018年   294篇
  2017年   360篇
  2016年   359篇
  2015年   293篇
  2014年   339篇
  2013年   1198篇
  2012年   293篇
  2011年   358篇
  2010年   331篇
  2009年   357篇
  2008年   344篇
  2007年   311篇
  2006年   321篇
  2005年   292篇
  2004年   295篇
  2003年   268篇
  2002年   273篇
  2001年   492篇
  2000年   445篇
  1999年   307篇
  1998年   198篇
  1997年   161篇
  1996年   131篇
  1995年   140篇
  1994年   149篇
  1993年   143篇
  1992年   207篇
  1991年   226篇
  1990年   213篇
  1989年   221篇
  1988年   211篇
  1987年   195篇
  1986年   243篇
  1985年   210篇
  1984年   163篇
  1983年   171篇
  1982年   117篇
  1981年   124篇
  1980年   88篇
  1979年   134篇
  1978年   76篇
  1977年   76篇
  1976年   71篇
  1974年   74篇
  1973年   70篇
  1972年   66篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
In patrilineal societies, surnames and Y-specific haplotypes and haplogroups are expected to be correlated. This characteristic could help defining an initial pool of suspects in forensic genetics analysis. Here we evaluated this correlation in a sample of Central-Brazilian men. Surnames and Y-SNP haplogroup and Y-STR haplotype were analyzed in 55 pairs of Central-Brazilian men sharing surnames (n = 110). Seven haplogroups and thirty-two haplotypes have been observed, none correlated solely to any of the twenty-eight surnames represented here. In this sample, two men with the same surname showed a chance of 0.41 of sharing a Y-specific haplogroup. This chance is higher for surnames of intermediate frequencies, whereas rare surnames show distinct chances as zero and one. Observed results may be over-estimated due to a predominance of a specific haplogroup (P92R7 = 49%) in the sample, what makes it possible for two men with no coancestry to share this haplogroup. Considering STR, only three pairs of men shared haplotypes. The average difference between the haplotypes in each pair was 2.45 mutational steps. This relatively low correlation is due to some historical and cultural peculiarities of the country, what makes it improper for forensic purposes in Brazil.  相似文献   
992.
993.
994.
995.
996.
S Begley 《Newsweek》2001,137(26):64-6, 68-9
  相似文献   
997.
998.
999.
1000.
The literature on the rural credit market in India (and elsewhere) has generally assumed that peasant farm households are rationed in their access to subsidized formal credit. Because of a lack of infrastructure and poor access to institutional credit, such farmers are exploited by means of an interlocked market connecting informal credit to the sale of paddy. The resulting gap, between the sale by a borrower of paddy at a predetermined low price, and the price of this commodity on the open market, constitutes the amount of what is termed a distress sale. The latter is itself influenced by the bargaining capacity (or lack thereof) of the peasant farmer who borrows on the informal market. Also of importance in determining whether or not a cultivator is compelled to resort to the informal credit market – and thus into an interlocked arrangement – is the need for additional liquidity to meet production costs and/or household consumption, as well as the monopsony nature of the paddy market. Data from Kalahandi district in Orissa suggest that access to formal credit is limited in rural areas although there exists a high demand for it, that a high degree of credit rationing by the formal lender occurs, and that poor implementation by the state of minimum support price policy all contribute to the need for informal loans and its attendant interlinkage.  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