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   25731篇
  免费   847篇
  国内免费   12篇
  26590篇
  2019年   246篇
  2018年   297篇
  2017年   336篇
  2016年   381篇
  2015年   298篇
  2014年   327篇
  2013年   1833篇
  2012年   629篇
  2011年   643篇
  2010年   407篇
  2009年   421篇
  2008年   600篇
  2007年   542篇
  2006年   481篇
  2005年   477篇
  2004年   443篇
  2003年   448篇
  2002年   465篇
  2001年   685篇
  2000年   674篇
  1999年   469篇
  1998年   244篇
  1992年   467篇
  1991年   452篇
  1990年   457篇
  1989年   458篇
  1988年   408篇
  1987年   420篇
  1986年   445篇
  1985年   481篇
  1984年   410篇
  1983年   376篇
  1982年   271篇
  1981年   314篇
  1980年   243篇
  1979年   439篇
  1978年   317篇
  1977年   286篇
  1976年   274篇
  1975年   409篇
  1974年   459篇
  1973年   484篇
  1972年   410篇
  1971年   403篇
  1970年   378篇
  1969年   401篇
  1968年   493篇
  1967年   476篇
  1966年   453篇
  1958年   252篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
241.
Psychotropic drug treatment in learning-disabled (LD), educable mentally retarded (EMR), and seriously emotionally disturbed (ED) children and adolescents receiving public school special education services was examined. The findings indicated that while treatment prevalence rates for EMR and ED groups were comparable, the rate for LD students was much lower. In the LD sample, pharmacotherapy was associated with higher ratings of behavioral deviance, longer placement in special education, less social integration, and greater peer rejection, which suggests that symptom severity is an important determiner of pharmacotherapy in this population.  相似文献   
242.
Locational representation in imagery: The third dimension   总被引:1,自引:0,他引:1  
Six experiments were conducted to test the relative processing characteristics of picture-plane and three-dimensional imagery as indexed by tasks that required subjects to keep track of successive locations in multiunit visual displays. Subjects were shown symmetrical displays either drawn on cardboard or constructed with three-dimensional blocks. They then were required to imagine these matrices and follow pathways through a series of adjacent squares (blocks) within the matrices. The pathways were described by a series of verbal terms that indicated the direction of the next square (block) in the pathway. Subjects experienced difficulty in performing the task with picture-plane displays composed of as few as 16 squares (4×4), but they rarely made errors with a three-dimensional matrix of 27 blocks (3×3×3). Performance with the three-dimensional task dropped dramatically when the matrix size was increased to 4×4×4. The results replicated previous findings that the image processing capacity for location in two-dimensional imagery is about three units in each direction, and they indicate that adding the depth dimension increases the capacity for representation of spatial location in imagery.  相似文献   
243.
The influence of sexual experience on preference behavior was investigated in adult female rats. In the first experiment, preference behavior for sexually active males versus estrous females was investigated in female rats who were experienced with mounting behavior. Preference of these mount experienced females was compared to preference of females who were naive in this respect. Mount experience with estrous females induced a female-directed preference in ovariectomized female rats, irrespective of whether the females were treated with OIL or with testosterone-propionate (500 micrograms TP, injected once 48 h prior to testing). Sexually naive, OIL-treated females did not show a preference for males or females, but TP induced a preference for a male. Individual differences in mount frequency were not correlated with preference behavior. In the second experiment, the influence of experience with feminine sexual responses on preference behavior was investigated. OIL-treated and TP-treated females oriented equally toward males and females when they had been given the opportunity to copulate with males prior to the preference tests. The results strongly suggest that prior sexual experience is an important determinant of preference behavior. The female's behavior during sexual interactions was, however, not predictive of later preference.  相似文献   
244.
This psychophysiological evaluation of an aerobic exercise program examined specifically whether aerobic training modified Pattern A for those individuals at behavioral risk for developing coronary heart disease, i.e., young Type A individuals. At pretest and posttest of this secondary prevention study, Type A and Type B subjects were assessed in three conditions: aerobic exercise program, nonaerobic activity (Aikido, a martial art) control, and notreatment control. After 10 weeks, Type A but not Type B subjects exhibited lower Pattern A behavior in the aerobic program than in control conditions. Average workout pulse rates and differentially reliable increases in aerobic capacity indicated that aerobic training was indeed aerobic, whereas aikido activity was not. Even though selected nonaerobic factors, such as locus of control and group participation, did not mediate the Pattern A decrease for Type A's when comparing aikido and aerobic conditions, changes in aerobic capacity may have been the mediator. Generalizability of the results and implications for theoretical development and clinical intervention are discussed.  相似文献   
245.
A considerable percentage of depressed patients do not respond to antidepressive treatment. Early indicators of prognosis are needed. The aims of this study are to examine (a) whether the interpersonal behavior of patients and psychiatrist, as assessed by means of direct observation of behavior during a baseline clinical interview, might have predictive value with respect to therapeutic outcome and (b) which predictive potency measures of psychomotor activation, as assessed by less refined methods, such as global clinical judgment, might have. In the analysis used, speech-pause behavior was taken as the basic structure of the interaction. The relations of other behaviors such as looking and hand and head movement with this structure were determined. Evidence is presented that in a group of 31 depressives, improvement after a period of 10 weeks was related to observed behaviors during a baseline interview. The behaviors of the patients are interpreted as relational or nonrelational. The relational behaviors (i.e., looking yesnodding, gesturing) occur less in patients who will improve, whereas the nonrelational behaviors (i.e., intensive body touching, head movements) occur more in these patients. The nonrelational behaviors are presumed to be indicative of the state of arousal. The predictive potency of these variables could not be explained by their relationship with the baseline severity of depression, which in itself also predicted improvement. Moreover, global clinical assessment of psychomotor activation (i.e., retardation and agitation) could not be related to outcome.  相似文献   
246.
This study compared the predictive validity of two types of overall assessment center ratings (clinical and mechanical) and two types of performance ratings (supervisor and subordinate). Data were gathered on approximately 50 law enforcement agency managers over a four-year time span. Results indicated that clinical predictions were not significantly better than mechanical ones and that prior performance ratings were better predictors of future performance ratings than were assessment centers. Further, dimension ratings within the assessment center were found to be unrelated to ratings of the same dimensions on the job four years later, supporting the notion of subtle criterion contamination (Klimoski & Strickland, 1977) and raising questions about the central assumptions underlying the assessment center approach.  相似文献   
247.
We compared the effect of two approaches, family counseling and support groups, for relieving the stress and burden experienced by care givers of dementia patients. Both treatments are designed to implement features of a stress-management model that have been identified in prior research with this population: providing information about the patient's disease and its effects on behavior, teaching behavioral problem solving for managing difficult behavior, and identifying potential support for care givers. Subjects were primary care givers of dementia patients living in the community; they included husbands, wives, daughters, and other relatives. Although subjects in the treatment groups made significant gains over time, they did not differ from wait-list subjects who showed similar improvements. One-year follow-up interviews indicated that gains made during the treatment period were maintained.  相似文献   
248.
249.
The results of an evaluation of the perfusion scintigraphy findings of 350 hospitalised neurological patients and 55 more strictly selected neurosurgical patients with cerebrovascular complaints, revealed an accuraty of 83%, a sensitivity of 89%, and a specificity of 83%. The selection of the patients had no influence on the results as a whole. Compared with contrast-medium angiography, incorrect diagnosis must be expected in 17% of the cases. This includes erroneous negative findings in 10% of the cases. Grounds for misinterpretations are suggested, and the biological and methodological limitations of the method are set forth.  相似文献   
250.
The use of computer based diagnostic decision and artificial intelligence are discussed in relation to the problems of validity and reliability of psychiatric diagnoses. The authors suggest a definition of a computer aided classificator as an existent decision system for an automatically analysis of findings.  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