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   30073篇
  免费   429篇
  国内免费   3篇
  2021年   68篇
  2020年   155篇
  2019年   197篇
  2018年   3625篇
  2017年   3001篇
  2016年   2482篇
  2015年   396篇
  2014年   332篇
  2013年   1179篇
  2012年   959篇
  2011年   2745篇
  2010年   2744篇
  2009年   1714篇
  2008年   2048篇
  2007年   2489篇
  2006年   383篇
  2005年   524篇
  2004年   487篇
  2003年   417篇
  2002年   425篇
  2001年   164篇
  2000年   176篇
  1999年   168篇
  1998年   184篇
  1997年   169篇
  1996年   148篇
  1995年   157篇
  1994年   125篇
  1993年   124篇
  1992年   130篇
  1991年   114篇
  1990年   115篇
  1989年   96篇
  1988年   83篇
  1987年   73篇
  1986年   80篇
  1985年   91篇
  1984年   107篇
  1983年   127篇
  1982年   126篇
  1981年   151篇
  1980年   109篇
  1979年   125篇
  1978年   132篇
  1977年   120篇
  1976年   107篇
  1975年   105篇
  1974年   106篇
  1973年   68篇
  1972年   63篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
In this paper, we describe an apparatus for measuring reaction times and movement times involved in reaching for real objects. Subjects view an object through a liquid crystal window, which serves as a shutter that can be made clear or opaque quickly (10 msec from opaque to clear, 30 msec from clear to opaque). The subject’s hand rests on a microswitch-equipped home key, and the object sits on a force-sensitive platform so that initiation of reach and time of contact with the object can be marked accurately. The apparatus interfaces with an IBM PC/AT through a digital I/O parallel port, so that reaction times and movement times are recorded automatically.  相似文献   
192.
Tachistoscopic presentation of stimuli on IBM PC-compatible computers is limited by a number of factors, including video retrace rates, screen scrolling, and the shape and density of picture elements. A method is presented for overcoming these difficulties through the use of enhanced graphic adapters or video graphic arrays. A C-language program demonstrates (1) synchronous scroll-free displays achieved by writing alternating images to “hidden” pages of video memory, (2) alternative techniques for erasing images, and (3) use of an empirically derived aspect ratio to produce symmetrical figures.  相似文献   
193.
Depression in some patients with spinal cord injuries may be clinically significant and, when present, should be treated to decrease morbidity including decreased physical functioning. Depression associated with spinal cord injury (SCI) may be misevaluated, due to (1) nonspecific multifactorial production of depression symptoms and (2) SCI-specific decrease in somatic sensory central nervous system input. The Somatic Suppression Hypothesis suggests that SCI patients have difficulty experiencing any intense emotion because of suppression of physiological arousal. In addition, cognitive processes that may reduce depression in SCI patients include: (1) attribution of somatic symptoms of depression to medical (biological) causes, (2) realistic, positive expectations for physical improvement, and (3) the perception that the disability of the SCI is only minimally related to the patient’s self-care after complete evaluation. Health personnel should accept lack of depression in SCI, and should encourage positive realistic expectations of recovery.  相似文献   
194.
A review of the literature suggests that a paucity of information exists regarding how culture-specific issues such as being both Black and gifted influence the psychological needs and personality development of gifted Black students. Stellar attempts, however, are currently underway to develop theories and perspectives of racial identity development among Black students. These theories and perspectives are discussed in an attempt to understand and address the psychological and social needs of gifted Black students.  相似文献   
195.
We find three factors to be associated with use of cost-benefit rules in everyday decisions. These are effectiveness in achieving desirable life outcomes, intelligence, and training in economics. We argue that these empirical findings support the claim that cost-benefit reasoning is normative.  相似文献   
196.
Subjects had to make a “remove” or “do not remove” life-sustaining measures decision in three right to die cases where the patients differed in competence; for half the subjects, a living will was present in all the cases, whereas, for the other half, it was not. Subjects also gave their determinative reasons for their decisions. Support for the right to die varied by case, but not by competency, or by the presence of a living will. The subjects' reasons were highly predictive of their decisions, and related to the way case-specific facts were construed, revealing a number of disparities between the way courts and citizens construe whether the patient's condition is “terminal,” “irreversible,” and “painful,” or not. Beyond construing facts differently, the results also revealed a disparity between evolving case law and the community's “common sense justice” over a fundamental belief: whether dying is seen as private matter, outside the bounds of State intervention, or not.  相似文献   
197.
The authors studied employment and roles of master's-level counselors in employee assistance programs (EAPs) and the services offered by different types of EAP organizations. The study focused on programs, workshops and seminars: assessment; counseling; consultation; and evaluation and marketing services offered by EAPs. Master's-level counselors were found to be similar to those with Master's of Social Work (MSW) degrees in employment rate and percentage of EAP staff. Both groups were the most frequently employed and constitute the greatest percentage of the professional mental health staff in EAPs. Also, counselors were found to be involved in all of the service areas studied within each type of EAP. Differences in counselors' roles among EAP types are discussed.  相似文献   
198.
199.
Naturalistic research methods were used in this study to collect the voices, ideas, and opinions of rural, working poor, Appalachian families from Southeast Ohio about the stress of poverty in family life and family coping in the face of poverty. This data should be of interest to the professional family therapist who practices with the working poor.  相似文献   
200.
The central terms of certain theories which were valued highly in the past, such as the phlogiston theory, are now believed by realists not to refer. Laudan and others have claimed that, in the light of the existence of such theories, scientific realism is untenable. This paper argues in response that realism is consistent with — and indeed is able to explain — such theories' having been highly valued and yet not being close to the truth. It follows that the set of highly-valued past theories cited by Laudan, presumed to militate against realism, is in fact innocuous to the doctrine. The argument hinges largely on identifying the grounds on which theory-adoption is actually performed.  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