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   10804篇
  免费   595篇
各国政治   448篇
工人农民   368篇
世界政治   830篇
外交国际关系   317篇
法律   7265篇
中国共产党   1篇
中国政治   56篇
政治理论   2073篇
综合类   41篇
  2021年   65篇
  2020年   199篇
  2019年   240篇
  2018年   237篇
  2017年   298篇
  2016年   307篇
  2015年   254篇
  2014年   286篇
  2013年   1037篇
  2012年   244篇
  2011年   321篇
  2010年   299篇
  2009年   307篇
  2008年   298篇
  2007年   275篇
  2006年   282篇
  2005年   266篇
  2004年   257篇
  2003年   253篇
  2002年   249篇
  2001年   469篇
  2000年   429篇
  1999年   295篇
  1998年   190篇
  1997年   154篇
  1996年   130篇
  1995年   117篇
  1994年   149篇
  1993年   135篇
  1992年   198篇
  1991年   223篇
  1990年   209篇
  1989年   218篇
  1988年   208篇
  1987年   196篇
  1986年   233篇
  1985年   206篇
  1984年   160篇
  1983年   172篇
  1982年   116篇
  1981年   125篇
  1980年   90篇
  1979年   132篇
  1978年   77篇
  1977年   75篇
  1976年   70篇
  1974年   74篇
  1973年   68篇
  1972年   67篇
  1970年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
95.
96.
Danger: implants     
The superheated debate over breast implants awakened a sleeping giant of an issue clouding "medical devices"--the government's clumsy nomenclature for any medical product that is not a drug, from breast implants and artificial hips to X-ray machines and surgical thread. Some 130 categories of high-risk devices are in use with little or no proof of safety, reliability or effectiveness. All appeared before 1976, the year that the Food and Drug Administration got the authority to regulate such products. Under activist chief David Kessler and with added clout from a 1990 law, the FDA plans to scrutinize the entire 130-item list. Five will get special attention starting early next year: saline-filled breast implants, inflatable penile implants, testicular implants, heart-bypass pumps and cranial stimulators. U.S. News has looked at all five devices, using FDA data obtained through the Freedom of Information Act. In-depth computer analysis suggested that penile implants deserve closer examination. Why is clear from the following report.  相似文献   
97.
98.
99.
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   
100.
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   
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