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   3663篇
  免费   111篇
各国政治   184篇
工人农民   124篇
世界政治   241篇
外交国际关系   135篇
法律   2440篇
中国政治   28篇
政治理论   600篇
综合类   22篇
  2020年   46篇
  2019年   48篇
  2018年   65篇
  2017年   82篇
  2016年   86篇
  2015年   60篇
  2014年   77篇
  2013年   359篇
  2012年   96篇
  2011年   107篇
  2010年   69篇
  2009年   70篇
  2008年   97篇
  2007年   115篇
  2006年   119篇
  2005年   107篇
  2004年   99篇
  2003年   109篇
  2002年   97篇
  2001年   175篇
  2000年   145篇
  1999年   91篇
  1998年   38篇
  1997年   31篇
  1996年   29篇
  1995年   22篇
  1994年   31篇
  1993年   27篇
  1992年   76篇
  1991年   84篇
  1990年   78篇
  1989年   96篇
  1988年   91篇
  1987年   77篇
  1986年   87篇
  1985年   82篇
  1984年   42篇
  1983年   51篇
  1982年   30篇
  1981年   36篇
  1980年   23篇
  1979年   32篇
  1978年   22篇
  1977年   29篇
  1975年   32篇
  1974年   33篇
  1973年   34篇
  1972年   33篇
  1971年   25篇
  1969年   25篇
排序方式: 共有3774条查询结果,搜索用时 31 毫秒
31.
32.
Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.  相似文献   
33.
Programme based on mathematical model of the process of dead body temperature changing was developed for estimation of postmortem interval. Automatic retrieval of problem solution was performed on programmable microcalculators of "Electronica MK-61" type using adaptive approach. Diagnostical accuracy in case of dead body being preserved in permanent cooling conditions is +/- 3%.  相似文献   
34.
This brief opposes the overturn of "Roe v. Wade" and resists weakening "Roe's central holding" that would allow states to overturn legal abortion. The brief was written for 885 law professors. "Roe" was not a "constitutional aberration," or "an exercise of raw, judicial power." Some members of the Supreme Court seem to think that the state has "an overriding interest" in protecting fetal life. Some Court members have questioned "Roe's" trimester framework. A person's decision to abort should be done privately. If women are not free to choose abortion, they will not have equality. There is an absence of "express rights of privacy and procreational freedom" in the Constitution. "Roe" was 1 instance of the Court's recognition of constitutional rights that are not named explicitly. Historical materials are drawn on to show the link between trends in society and the "judicial recognition of unenumerated rights." The most serious questions about "Roe" deal with its trimester framework. Justice Blackmun's majority opinion said that the 1st trimester of pregnancy was personal. "Roe" said that abortions created a medical risk at the beginning of the 2nd trimester. Therefore, the government was more interested in the health of the mother at that time. The state could then regulate abortion "in ways that are reasonable related to maternal health." The start of the 3rd trimester was when the fetus was viable. The right of a woman to end her pregnancy "offends powerful moral forces." Some of "Roe's" critics had their scientific facts wrong. Medical authorities think Justice O'Connor is mistaken when she says that "Roe" is "on a collision course with itself." The 23rd to 24th week of pregnancies where the fetal organs can "sustain life outside the womb." This has not changed since "Roe" was decided in 1973, nor is it likely to in the future. Some "amici" believe that the state can never have an interest in the fetus. The state can not have an interest in the fetus distinct from the woman who will give birth to it. During previability, restricting a woman's procreational rights would not be scientifically supportable. The state does have an interest in "upholding the value of human life." "Roe" is "within the mainstream" of constitutional jurisprudence and should be reaffirmed.  相似文献   
35.
Book reviews     
Transborder Data Flows (Proceedings of an OECD Conference) Edited by Hans‐Peter Gassmann North Holland (Elsevier Science Publishers) 1985, US$74.00

Plastic and Electronic Money: New Payment Systems and Their Implications Patrick Frazer Woodhead Faulkner Limited 1985 £35

A User's Guide To Computer Contracting: Forms, Techniques and Strategies Davis, Allen, Bowman and Armstrong Harcourt Brace Jovanovich 1985, $75

Legal Protection of Computer Programs and Data C. Millard Sweet & Maxwell/Stevens 1985, £24

Piracy of Phonograms Gillian Davies ESC Publishing Ltd. 1986. 2nd edition. £17.95.

Biotechnology and Patent Protection—An International Review F. K. Beier, R. S. Crespi and J. Straus O.E.C.D. 1985, £5

Protecting Privacy in Two‐Way Electronic Services David H. Flaherty Mansell Publishing Company 1985, £23.50

High‐Tech Espionage Jay Tuck Sidgwick and Jackson Ltd 1980, £10.95  相似文献   

36.
A series of related studies (Freedman and Berelson, 1976; Mauldin and Berelson, 1978; and Tsui and Bogue, 1978) have presented empirical findings based on multiple regression analysis which indicated that family planning program effort (FP), as measured by an index developed by Lapham and Mauldin (1972), was the single most important predictor of (or influence on) fertility reduction in less-developed countries (LDCs). The basic results have been confirmed repeatedly. A more extensive data set was used to extend the analysis to a comparison of results of corss-sectional models circa 1970 and 1980. The study builds upon the results of past studies yet differs from them in several ways. All the variables in the present study were measured at 2 points in time: circa 1970 and circa 1980, allowing a comparison between cross-sectional models for 1970 and 1980. Among the cases included in this multivariate analysis was China, a country usually excluded for lack of data. The analysis was extend to 85 countries. Cases were weighted by population, having the effect of increasing the impact of larger countries such as India and China on the outcome of the analysis. Total fertility rate (TFR) was used as an indicator of fertility. For 1970, family planning program effort had the strongest direct influence on fertility (a result consistent with previous studies). Life expectancy at birth was the other direct influence. The direct influence of life expectancy at birth was less than that of family planning, but the total influence was greater. After life expectancy and family planning, school enrollment and relative educational status of women had the strongest indirect and total influences. The other variables all had a positive influence on fertility. When the total variance attributable was considered, directly and indirectly to each of the independent variables, urbanization, carlorie supply, and per capita gross national product all accounted for less than 5% of the variance in fertility, all of it indirect. Life expectancy, family planning, and school enrollment each explained (directly plus indirectly) more than 10% of the variance in fertility. The pattern differed somewhat for 1980. Calorie supply, per capita gross national product, and relative educational status of women had no influence, direct or indirect on fertility. Also for 1980, life expectancy had a stronger direct influence on fertility than family planning. Overall, life expectancy at birth, family planning program effort, and total school enrollment emerged as the principal influences on fertility.  相似文献   
37.
38.
39.
40.
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