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   13385篇
  免费   276篇
  国内免费   86篇
  2012年   1358篇
  2011年   1568篇
  2010年   333篇
  2009年   159篇
  2008年   1192篇
  2007年   1182篇
  2006年   1134篇
  2005年   885篇
  2004年   818篇
  2003年   810篇
  2002年   688篇
  2001年   466篇
  2000年   536篇
  1999年   224篇
  1998年   60篇
  1997年   48篇
  1996年   44篇
  1995年   27篇
  1994年   47篇
  1993年   48篇
  1992年   52篇
  1991年   57篇
  1990年   63篇
  1989年   65篇
  1988年   73篇
  1987年   60篇
  1986年   55篇
  1985年   72篇
  1984年   38篇
  1983年   56篇
  1982年   43篇
  1981年   48篇
  1980年   21篇
  1979年   31篇
  1978年   39篇
  1965年   35篇
  1964年   26篇
  1963年   32篇
  1959年   41篇
  1958年   129篇
  1957年   128篇
  1956年   114篇
  1955年   92篇
  1954年   99篇
  1953年   82篇
  1952年   83篇
  1951年   75篇
  1950年   64篇
  1949年   52篇
  1948年   43篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
121.
Sexuality education for children and young adults is one of the most heavily debated issues facing policy-makers, national AIDS program planners, and educators, provoking arguments over how explicit education materials should be, how much of it there should be, how often it should be given, and at what age instruction should commence. In this context, the World Health Organization's Global Program on AIDS' Office of Intervention Development and Support commissioned a comprehensive literature review to assess the effects of HIV/AIDS and sexuality education upon young people's sexual behavior. 52 reports culled from a search of 12 literature databases were reviewed. The main purpose of the review is to inform policy-makers, program planners, and educators about the impact of HIV and/or sexuality education upon the sexual behavior of youth as described in the published literature. Of 47 studies which evaluated interventions, 25 reported that HIV/AIDS and sexuality education neither increased nor decreased sexual activity and attendant rates of pregnancy and sexually transmitted diseases (STDs). 17 reported that HIV and/or sexuality education delayed the onset of sexual activity, reduced the number of sex partners, or reduced unplanned pregnancy and STD rates Only 3 studies found increases in sexual behavior associated with sexuality education. Inadequacies in study design, analytic techniques, outcome indicators, and the reporting of statistics are discussed.  相似文献   
122.
While Cameron is right about the need for Christians to contribute more visibly to medical ethical debates, he is wrong in his analysis of bioethics. Marsha D.M. Fowler and Andrew Jameton find specific problems in several points of Cameron's argument, particularly where the Hippocratic Oath and patient autonomy are concerned.  相似文献   
123.
We examined self- and cross-citation practices in JABA and JEAB from 1983 through 1992. Mean levels of self-citation for JABA and for JEAB were 22.6% and 36.1%, respectively. Overall, 2.4% of JABA citations were JEAB articles, and 0.6% of JEAB citations were JABA articles, which suggests limited integration of basic and applied research.  相似文献   
124.
Humphrey and Dahlstrom (1995) presented a study on the comparability of MMPI/MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) profiles in which they concluded that "the bases for clinical interpretation derived from the MMPI and MMPI-2 profiles were sufficiently at variance to require different conclusions" [sic] (p. 2). In this brief critique, we identify procedural and data-analytical deficiencies that invalidate Humphrey and Dahlstrom's argument. Their blanket recommendation based on this argument, namely, that clinicians routinely plot both MMPI and MMPI-2 profiles, is unwarranted.  相似文献   
125.
ABSTRACT Biomedical experimentation on animals is justified, researchers say, because of its enormous benefits to human beings. Sure, animals suffer and die, but that is morally insignificant since the benefits of research incalculably outweigh the evils. Although this utilitarian claim appears straightforward and relatively uncontroversial, it is neither straightforward nor uncontroversial. This defence of animal experimentation is likely to succeed only by rejecting three widely held moral presumptions. We identify these assumptions and explain their relevance to the justification of animal experimentation. We argue that, even if non-human animals have considerably less moral worth than humans, experimentation is justified only if the benefits are overwhelming. By building on and expanding on arguments offered in earlier papers, we show that researchers cannot substantiate their claims on behalf of animal research. We conclude that there is currently no acceptable utilitarian defence of animal experimentation. Moreover, it is unlikely that there could be one. Since most apologists of animal experimentation rely on utilitarian justifications of their practice, it appears that biomedical experimentation on animals is not morally justified .  相似文献   
126.
禁地,亦即指由于地形原因而不可进入的地区,尤其是指出于政治、宗教或其他动机而作出的决策所禁止入内的区域(场所、城市、国家)。禁地往往蒙上了一种神秘的气氛.几乎必然会引起人们的好奇。到达拉萨曾是几代探险家的梦想。这一地区不仅对外人封闭,而且对“内部人”也封闭:任何人不得离开“外出”。德川幕府对日本实行的隔绝就是这样一种双向隔离。当然.地理条件也有助于这种隔离,因而使之轻易地付诸实行。有人指出(或许这种说法不够严肃).举世闻名的中国长城不仅意味着防范匈奴入侵,更意味着防止中国人逃离。史料也表明中国过…  相似文献   
127.
128.
Four homing pigeons were trained over 5 months in a zero-delay, “arbitrary” matching-to-sample procedure with sample and comparison stimuli presented on any of three response keys. Birds were also required to complete a fixed-ratio 10 requirement on both sample and comparison stimuli to terminate their presentation. The procedure resulted in the establishment of relations that were not specifically trained and that can be characterized by the property of transitivity in a stimulus equivalence context. This result was in contrast with the findings obtained from most previous research with nonhuman subjects.  相似文献   
129.
宗教非常重要 宗教关注整个生命的终极价值,是涉及人类的非常重大的事情。 宗教起团结作用 宗教起团结联合的作用,但宗教一多则起分裂作用。因为各种宗教是分裂的,这对宗教来说是有害的。 传统的区分或分割 每一传统文化均建立它关于生命本质及其价值的原则,并且传授这些原则,使之成为人们的行为规范,因为人们相信这些原则是正确的。但是早期产生的关于生命与价值的信念,缺乏足够的知识,只是因为人们信以为真而且非常重要,这些信念便被视为神圣不可侵犯,是生命不可或缺的。这些原则在孤立环境中,甚至解释力不强时,也还可能使人们获得幸福。但当人们与其他传统的原则与实践发生冲突,另一种传统威胁到他们自己传统时,每个人都相信自己的传统正确而另一种传统错误,他一定会设法反对它。  相似文献   
130.
一、思想背景 1929年秋A.J.艾耶尔来到牛津时,他并没有想到要成一名职业哲学家。他读过两本哲学著作,一本是罗素的《怀疑论文集》(1928),一本是摩尔的《伦理学原理》(1903)。这些选择有着重要的意义。艾耶尔总是把自己看作罗素的继承人,他效法罗素的思想,包括其内容反其轻率的表达;而且在某种程度上他还效法罗素的生活方式,包括其政治态度和恋爱方式。他从摩尔那里得到的显然要少得多,尽管他也很尊重摩尔,正如《语言、真理和逻辑》序言中所表明的那样。一个重要的相似之处是,摩尔和艾耶尔都是由于其他哲学家的主张而非哲学以外的数学或科学问题、历史或日常生活问题而引发进行哲学思索的。 在20年代,正统的唯心主义在苏格兰以外的地方或多或少已经灭绝。普里查德在1915年发表于《心》上的一篇文章中激烈地批判了罗素的知识论,而且他和约瑟夫都坚持敌视罗素的逻辑。普里查德认为,作为一个伦理推断论者,摩尔是那些在道德哲学中犯了根本错误的人当中的一个。普里查德晚年出版了唯一的一部著作《康德的认识论》(1909),约瑟夫的主要著作《逻辑导论》出版于1916年。  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