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   35448篇
  免费   1513篇
  国内免费   8篇
  36969篇
  2020年   392篇
  2019年   534篇
  2018年   688篇
  2017年   727篇
  2016年   719篇
  2015年   505篇
  2014年   650篇
  2013年   2741篇
  2012年   1173篇
  2011年   1206篇
  2010年   723篇
  2009年   707篇
  2008年   1031篇
  2007年   1013篇
  2006年   954篇
  2005年   857篇
  2004年   817篇
  2003年   718篇
  2002年   769篇
  2001年   1043篇
  2000年   959篇
  1999年   735篇
  1998年   403篇
  1997年   325篇
  1996年   319篇
  1992年   559篇
  1991年   550篇
  1990年   531篇
  1989年   545篇
  1988年   537篇
  1987年   500篇
  1986年   523篇
  1985年   578篇
  1984年   457篇
  1983年   437篇
  1982年   362篇
  1981年   343篇
  1979年   529篇
  1978年   386篇
  1976年   369篇
  1975年   439篇
  1974年   493篇
  1973年   512篇
  1972年   411篇
  1971年   383篇
  1970年   382篇
  1969年   410篇
  1968年   490篇
  1967年   423篇
  1966年   424篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
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   
992.
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   
993.
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   
994.
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   
995.
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   
996.
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   
997.
The focus of the present study was on the intersegmental relationships that emerge when both task and oganismic constraints are imposed upon the coordination system. Seven right-handed subjects were required to reach and grasp a cup (hand transport phase) and place it on a designated target (cup transport phase), using either their preferred or nonpreferred hand. The kinematics of the movement were examined as a function of task (grasping a full cup versus grasping an empty one) and organismic (preferred or nonpreferred hand) constraints. During the hand transport phase, a task constraint effect was revealed through an increase in the low-velocity phase for the full cup condition. This constraint coexisted with a decrease in angular motion of the shoulder and elbow joints, indicating subjects reduced the number of variables to be independently controlled in the final homing-in stage of the movement. Accompanying this decrease in angular change was an increase in the displacement of the trunk. During the cup transport phase, the trunk was shown to contribute significantly more to the movement in the full cup condition and for the left hand movements, thereby increasing the stability of the movement system. These findings are in agreement with Bernstein's (1967) notion of fixating parts of the body as an initial solution to a movement problem, and they lend support to the concept of a proximodistal organization of coordination.  相似文献   
998.
Both theoretical arguments and laboratory evidence indicate that society awards earned dignity (worth) to persons perceived as voluntarily performing praiseworthy behaviors. Laboratory research, as well as common observation, indicates also that society accords an intrinsic dignity unconditionally to all people. On a questionnaire given in class, college students reported increased dignity earned by the Russians from their praiseworthy (i.e., embracing freedom) and voluntary rejection of the attempted coup in 1991. The questionnaire also revealed a general belief in intrinsic dignity. External evidence for earned dignity is shown by increased international support for the Russians after rejection of the coup. This convergence of laboratory and external data validates the laboratory techniques for studying social perception of human dignity.  相似文献   
999.
La présente étude vise à examiner la nature des liens entre les styles d'attachement (sécurisant, anxieux/ambivalent et évitant), la solitude et la détresse psychologique (dépression, anxiété, agressivité et problèmes cognitifs) chez des jeunes adultes. L'échantillon se compose de 407 étudiants de niveau collégial dont l'âge moyen se situe à 18 ans. Les sujets doivent répondre à deux questionnaires d'évaluation du style d'attachement, à l'échelle de solitude UCLA, ainsi qu'à l'index de symptômes psychiatriques. Les résultats laissent voir que les individus ayant un style d'attachement sécurisant rapportent moins de symptômes de dépression et de sentiments de solitude que les sujets des styles anxieux/ambivalent et évitant. De même, ils vivent moins d'anxiété, d'agressivité et de problèmes cognitifs que les individus du style anxieux/ambivalent. Par ailleurs, les individus du style d'attachement anxieux/ambivalent sont plus déprimés, anxieux et agressifs que les individus du style évitant. Par contre, aucune différence significative ne ressort entre les sujets des styles d'attachement anxieux/ambivalent et évitant sur le plan des problèmes cognitifs et de la solitude. Des analyses de régression multiple montrent que l'attachement anxieux/ambivalent et la solitude expliquent un pourcentage significatif de la variance associée à la détresse psychologique. Enfin, il ressort que la solitude joue un rôle modérateur dans la relation unissant l'attachement non sécurisant et les problèmes de nature cognitive, alors qu'elle joue un rôle médiateur dans la relation entre l'attachement sécurisant, la dépression et l'anxiété.  相似文献   
1000.
The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.5 years) repeatedly lifted a barbell. A biomechanical analysis that used a linked segment model revealed that the summed rotations of body segments during lifting yielded a specific rate of change of the angular momentum of the entire body. This equaled the external moment provided by Fsubg; relative to CoG. This implies that multisegment movements involve control of the angular momentum of the entire body through an appropriately directed Fsubg;. Thus, in dynamic tasks Fsubg; is pointed away from rather than lined up with the CoG, as is the case in static tasks.  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