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   21575篇
  免费   1879篇
  国内免费   1265篇
  24719篇
  2024年   42篇
  2023年   342篇
  2022年   316篇
  2021年   369篇
  2020年   734篇
  2019年   759篇
  2018年   795篇
  2017年   884篇
  2016年   806篇
  2015年   532篇
  2014年   710篇
  2013年   2209篇
  2012年   486篇
  2011年   749篇
  2010年   493篇
  2009年   716篇
  2008年   884篇
  2007年   967篇
  2006年   929篇
  2005年   788篇
  2004年   683篇
  2003年   556篇
  2002年   547篇
  2001年   369篇
  2000年   330篇
  1999年   286篇
  1998年   221篇
  1997年   171篇
  1996年   156篇
  1995年   131篇
  1994年   112篇
  1993年   98篇
  1992年   85篇
  1991年   56篇
  1990年   59篇
  1989年   45篇
  1988年   49篇
  1985年   486篇
  1984年   595篇
  1983年   513篇
  1982年   583篇
  1981年   561篇
  1980年   555篇
  1979年   500篇
  1978年   558篇
  1977年   436篇
  1976年   437篇
  1975年   344篇
  1974年   341篇
  1973年   285篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
The theory that the subjective experience of crowding results from an attribution of arousal process was examined. Specifically, it was predicted that subjects who were aroused by having their personal space violated would experience less crowding if they were led to believe that some other environmental factor was responsible for the arousal. Groups of subjects were placed in a room in which their personal space was either violated or not violated. Some subjects were told that either an arousing or a relaxing subliminal noise would be played into the room. (Actually there was no noise.) Other subjects were told nothing about subliminal noise. The subjects worked on a number of tasks and were then asked to report how crowded they felt. The noise manipulation had no effect on subjects' performance nor on feelings of crowdedness when their personal space was not being violated. However, when there was a violation of personal space, subjects who felt the noise would arouse them reported being less crowded and performed better than subjects in the relaxing noise or no explanation conditions. It was suggested that subjects attributed their arousal to the “arousing noise” and hence felt less crowded.  相似文献   
972.
973.
In three experiments, subjects imposed sentence in a criminal case before and after reading the harsh sentence imposed by the trial judge. They then read and imposed sentence in another case. In one experimental condition the subjects anticipated learning the judge's sentence in Case 2; in the other condition they were told not to anticipate learning the judge's sentence. Control subjects made their judgments without ever seeing the judge's sentence. Direct influence was the change in sentences within cases; indirect influence was the difference between initial sentences in Cases 1 and 2. Though direct influence was minimal and not significant, indirect influence was substantial, and was greater in the anticipation than no-anticipation than control conditions, indicating that both modification of the judgmental process and anticipatory conformity were operating. Indirect influence may then reflect a change of either type, depending on a number of methodological and other factors.  相似文献   
974.
This paper reviewed the studies which evaluated counseling groups in senior high school settings. A methodological evaluation was conducted within four areas: subjects, counselors, treatment, and outcome criteria. The studies were reviewed according to the type of outcome measure: achievement, attitude and personality, behavioral, and vocational. Three levels of voluntariness (voluntary, semivoluntary, and nonvoluntary) were examined in relation to outcome. Subjects who were free to volunteer for the group experience achieved greater gains than subjects who were coerced into participation. Overall, behavioral and directive groups achieved greater success than nondirective or client-centered groups. The time spent on topics relating to treatment goals appeared to be an important factor for success. Future researchers should assess the effects of treatment on each participant instead of relying upon group mean changes.  相似文献   
975.
Six experiments with rat subjects investigated the role of conditioning in morphine tolerance. Concurrent assessments of body temperature and pain sensitivity were conducted. Experience with morphine produced tolerance to its analgesic effects but enhancement of its hyperthermic effects. Environmental novelty enhanced analgesia but not body temperature (Experiments 1 and 4). Under conditions in which a discriminated hyperthermic CR provided clear evidence that morphine-environment learning had developed, discriminated analgesic tolerance was not obtained (Experiments 2 and 3). Similarly, whereas placebo administrations extinguished the hyperthermic CR (Experiments 4 and 6), analgesic tolerance remained unaffected (Experiments 4, 5, and 6). These experiments suggest that the pyretic and analgesic systems are differentially sensitive to conditioning and the effects of novelty.  相似文献   
976.
The first experiment showed the monkeys could recall whether an object had been rewarded with peanuts or with sultanas, two equally preferred foods. The second investigated the effect of rewarded trials with an object on monkeys' ability to recall a nonrewarded trial with the same object. The third demonstrated that monkeys could use the memory of reward to predict nonreward and the memory of nonreward to predict reward, in a Win-Shift Lose-Stay paradigm. The fourth found differences between Win-Shift Lose-Stay and Win-Stay Lose-Shift in the rate at which associations between objects and reward events were forgotten. These results are discussed in relation to D. L. Medin's (In A. M. Schrier, Ed., Behavioral primatology, Hillsdale, N.J.: Erlbaum, 1977, Vol. I, pp. 33–69) distinction between informational and hedonic effects of reward in monkeys. It is argued that the association between an object and a reward event is represented in memory by many independent traces, different traces recording the object's association with different attributes of the reward event.  相似文献   
977.
Three properties of the cusp catastrophe: bimodality, inaccessibility, and hysteresis were evaluated in rabbit eyelid conditioning. Bimodality was evidenced by the fact that responding tended to occur at either very low or very high levels, and inaccessibility by the fact that intermediate levels of responding were rarely encountered. Hysteresis was demonstrated when: (a) levels of responding attained under a continuous schedule of reinforcement were largely maintained by a schedule which was too lean to promote conditioning by itself; and (b) levels of responding attained with a high intensity unconditional stimulus were largely maintained by a lower intensity unconditional stimulus which was too weak to promote conditioning in its own right. These results are consistent with the model of conditioning suggested by P. W. Frey and R. J. Sears (Psychological Review, 1978, 85, 321–340) which postulates response-mapping rules based on the cusp catastrophe.  相似文献   
978.
Effects of aversive CSs upon dogs' instrumental avoidance responding were assessed as a function of the Pavlovian conditioning parameters using off-baseline (Experiment 1) and on-baseline (Experiment 2) conditioning procedures. In each experiment, three UCS intensitites (2, 6, and 10 mA) were crossed factorially with two CS-UCS intervals (10 and 90 sec) yielding six groups. After 4 days of conditioning, the CS-produced effects on avoidance were determined primarily by an interaction between Pavlovian procedure (off- versus on-baseline) and UCS intensity. With off-baseline conditioning, CS-produced facilitation of avoidance was an increasing function of the UCS intensity. However, with on-baseline conditioning, only the CS paired with weak UCS facilitated avoidance, and the CS paired with the strong UCS suppressed responding. This reversing parametric function poses problems for two-process motivational theories of avoidance.  相似文献   
979.
Two experiments examined the effectiveness of two amounts of flooding or response-prevention on hastening avoidance response extinction and on reducing CS-produced suppression of bar-pressing for food. In Experiment 1, 20 and 30 flooding trials were both shown to be effective in hastening the extinction of a well-learned shuttlebox avoidance response. In Experiment 2, rats trained under comparable conditions to those in Experiment 1 were tested following flooding for the CER in a different apparatus. The results indicated that 30, but not 20, flooding trials were sufficient to reduce the CER. In each experiment the results of additional control groups equated with the flooded groups for nonreinforced CS exposure also revealed a dissociation between the effectiveness of this CS time control procedure in hastening avoidance response extinction and in reducing the CER. Further comparisons showed that although 30 flooding trials did reduce the CER, the same total duration of nonreinforced CS Exposure in the form of avoidance extinction trials did not. Thus the context in which CS exposure occurs may affect the dynamics of extinction of the CER. The experiments are discussed in the broader context of dissociation of various indices of fear in humans.  相似文献   
980.
In three experiments, the retention of conditioned inhibition in rats was examined over long intervals. Retention deficits of conditioned inhibition were found at 21 days, although conditioned excitation was relatively stable over time. This loss of conditioned inhibition was demonstrated using both the summation and the retardation of learning techniques in a bar-press suppression paradigm. Furthermore, retention differences were found between within-groups and between-groups generalization tests of conditioned inhibition, using the summation procedure. These differences were interpreted within a retrieval-oriented model of memory.  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