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   35538篇
  免费   1489篇
  国内免费   8篇
  37035篇
  2020年   412篇
  2019年   518篇
  2018年   720篇
  2017年   753篇
  2016年   727篇
  2015年   497篇
  2014年   633篇
  2013年   2753篇
  2012年   1191篇
  2011年   1262篇
  2010年   750篇
  2009年   678篇
  2008年   1081篇
  2007年   1016篇
  2006年   946篇
  2005年   809篇
  2004年   784篇
  2003年   722篇
  2002年   734篇
  2001年   1044篇
  2000年   957篇
  1999年   730篇
  1998年   399篇
  1997年   321篇
  1992年   553篇
  1991年   556篇
  1990年   533篇
  1989年   547篇
  1988年   540篇
  1987年   504篇
  1986年   525篇
  1985年   579篇
  1984年   455篇
  1983年   435篇
  1982年   357篇
  1981年   342篇
  1979年   526篇
  1978年   380篇
  1977年   313篇
  1976年   359篇
  1975年   433篇
  1974年   488篇
  1973年   508篇
  1972年   410篇
  1971年   387篇
  1970年   380篇
  1969年   411篇
  1968年   496篇
  1967年   425篇
  1966年   429篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Loomingness and the Fear of AIDS: Perceptions of Motion and Menace   总被引:1,自引:0,他引:1  
The authors examined the role of "perceived loomingness" in fear of HIV. Perceived loomingness refers to perceptions of rapid forward movement and instantaneous changes in the distance and danger of a potential threat (Riskind, 1992). One hundred and twenty undergraduates rated vignettes of two public encounters with an HIV-positive stranger. High-HIV fear subjects perceived greater loomingness and danger in these vignettes than did low-HIV fear subjects. Regression analyses that tested for a mediated model confirmed that the perceptions of loomingness may spark threat cognitions (such as the probability and imminence of harm), which, in turn, lead to fear. As predicted by the harm-looming model, loomingness also had some effects on fear that were not mediated by such standard threat cognitions.  相似文献   
992.
High-probability requests were used to increase social interactions in 3 young boys with severe disabilities who had been identified as severely socially withdrawn. A multiple baseline design across participants was used to evaluate the effects of high-probability request intervention on (a) social initiations, (b) social responses, (c) continued interactions, and (d) performance of high- and low-probability requests. The students were observed in a second setting to examine generalization effects across peers who did not participate in the training sequence and settings. The results demonstrated that the high-probability requests increased the students' responsiveness to low-probability requests to initiate social behavior. Increases were also found in (a) unprompted initiations and extended interactions to the training peers, (b) unprompted initiations and extended interactions to peers who were not involved in the training procedure, and (c) generalized unprompted initiations and interactions in a second nontraining setting. The students maintained increased levels of initiations and interactions after all prompts were removed from both the training and nontraining settings.  相似文献   
993.
994.
Joel E. Haugen 《Zygon》1995,30(4):553-572
Abstract. A central aim of Ralph Wendell Burhoe's scientific theology is to define and interpret the meaning of human existence in relation to “ultimate reality.” As such, it can be understood as an exercise in theological anthropology. For Burhoe, this ultimate reality is “nature,” understood as the total reality system which is studied by the sciences and which the sciences are showing to be the sole determiner of the way things are. This article discusses various aspects of Burhoe's theological anthropology, as well as its value and credibility, and raises questions concerning his understanding of the value of the individual and the problems of evil and human sinfulness.  相似文献   
995.
Clinicians are commonly asked to participate in the determination of an individual's mental capacity and susceptibility to undue influence. Vague statutory definitions and lack of operational criteria for both determinations have contributed to inconsistency in the quality and usefulness of expert input to these determinations. Questionnaire responses of 119 probate judges from the U.S. indicate that this input is quite influential despite the problems mentioned above. This paper presents and discusses the judges' views on selected procedural and conceptual aspects of expert evaluation and testimony.  相似文献   
996.
Recent legislative and regulatory developments have focused attention on older adults' capacity for involvement in health care decision-making. The Omnibus Budget Reconciliation Act of 1987 (OBRA 87) focused attention on the rights of nursing home residents to be involved in health care decision-making to the fullest extent possible. This article uses data from the 1987 National Medical Expenditure Survey (NMES) to examine rates of incapacity for health care decision-making among nursing home residents. Elements of the Oklahoma statute were used to operationalize decision-making incapacity: disability or disorder, difficulty in decision-making or communicating decisions, and functional disability. Fifty-three percent of nursing home residents had a combination of either physical or mental impairment and an impairment in either self-care or money management. The discussion focuses on the policy and practice implications of significant rates of incapacity among nursing home residents.  相似文献   
997.
This study examined whether variables at individual, unit, and suborganization levels influence the extent to which the knowledge and skills learned in employee involvement (EI) training are generalized beyond specific EI activities. Training generalization occurs when the knowledge and skills learned in training for a specific purpose in one context (e.g., EI training for use in quality circles) are applied by trainees in another context (e.g., regular job duties). A multiple-cross-level design using data gathered from 252 employees and supervisors drawn from 88 units across 11 suborganizations provided support for both individual and situational effects. Hierarchical regression results demonstrated that characteristics at individual, unit, and suborganization levels significantly predicted the extent EI knowledge, skills, and attitudes were generalized to the core job activities. As predicted, trainees were more likely to use EI training in performing core job activities the more EI activities they participated in, the greater their commitment to the organization, and the less cynical they were about the likelihood of positive organizational change. Contrary to expectations, more generalization of EI training was found to occur in units and suborganizations with less participative climates.  相似文献   
998.
Six hens were exposed to several concurrent (second-order) variable-interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response- and time-allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domestic hens.  相似文献   
999.
The authors investigated the effectiveness of various commonly used Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) indices of exaggeration and malingering in detecting suspected malingering in a military sample of 121 enlisted men. To maximize external validity, only men undergoing psychological evaluation were used as participants. Forty-one participants were identified as suspected malingerers through multiple criteria and were contrasted with schizophrenic-spectrum and clinic outpatient groups. To improve internal validity, the 41 suspected malingering participants were asked to retake the test without exaggerating. Results revealed that there were many false positives and fewer, but nonetheless many, false negatives with standard malingering indices. It appeared that the Gough Dissimulation scale (Gough, 1947) might hold the most promise as a measure of malingering, but other scales are also useful. Individual comparisons between different samples and implications for MMPI-2 (Butcher et al., 1989) are presented.  相似文献   
1000.
Food-deprived rats (at 80% of their free-feeding weights) were exposed to a fixed-time 60-s schedule of food-pellet presentation and developed schedule-induced drinking. Lick-dependent signaled delays (10 s) to food presentation led to decreased drinking, which recovered when the signaled delays were discontinued. A major effect of this punishment contingency was to increase the proportion of interpellet intervals without any licks. The drinking of yoked control rats, which received food at the same times as those exposed to the signaled delay contingency (masters), was not consistently reduced. When food-deprivation level was changed to 90%, all master and yoked control rats showed decreases in punished or unpunished schedule-induced drinking. When the body weights were reduced to 70%, most master rats increased punished behavior to levels similar to those of unpunished drinking. This effect was not observed for yoked controls. Therefore, body-weight loss increased the resistance of schedule-induced drinking to reductions by punishment. Food-deprivation effects on punished schedule-induced drinking are similar to their effects on food-maintained lever pressing. This dependency of punishment on food-deprivation level supports the view that schedule-induced drinking can be modified by the same variables that affect operant behavior in general.  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