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   3273篇
  免费   1030篇
  国内免费   32篇
  2019年   35篇
  2018年   42篇
  2017年   53篇
  2016年   38篇
  2014年   45篇
  2013年   235篇
  2012年   71篇
  2011年   107篇
  2010年   129篇
  2009年   200篇
  2008年   121篇
  2007年   129篇
  2006年   94篇
  2005年   105篇
  2004年   122篇
  2003年   113篇
  2002年   87篇
  2001年   147篇
  2000年   71篇
  1999年   114篇
  1998年   89篇
  1997年   75篇
  1996年   108篇
  1995年   88篇
  1994年   90篇
  1993年   88篇
  1992年   106篇
  1991年   100篇
  1990年   92篇
  1989年   90篇
  1988年   65篇
  1987年   60篇
  1986年   56篇
  1985年   38篇
  1984年   52篇
  1982年   49篇
  1980年   33篇
  1979年   37篇
  1976年   33篇
  1973年   38篇
  1972年   52篇
  1971年   46篇
  1968年   61篇
  1967年   43篇
  1966年   55篇
  1965年   43篇
  1964年   80篇
  1963年   73篇
  1962年   48篇
  1961年   39篇
排序方式: 共有4335条查询结果,搜索用时 46 毫秒
941.
The influence of sex of manager and sex of subordinate on subordinates' reactions to supervision and work evaluation was examined. Attitude data from 463 office employees were analyzed within an ANOVA framework. There were 296 female subordinates and 35 male subordinates working under women managers and 111 female subordinates and 21 males subordinates working under men managers. The hypothesized interaction effect for sex of manager and sex of subordinate on reactions to supervision and work evaluation was supported in only one of four tests. Male subordinates working for male managers were least likely to understand how their performance was evaluated. There were no significant results when subordinate ratings of general supervision, performance ratings, and manager favoritism were used as dependent variables. The results are discussed in terms of sex-role stereotypes and actual job behaviors of men and women managers.  相似文献   
942.
本文用不能躲避的间歇脚底电刺激引起大鼠应激,用电刺激鼠尾-嘶叫法测定镇痛效应,研究下丘脑弓状核(脑内β-内啡肽能神经元胞体集中的部位)、中缝背核(脑内5-羟色胺能神经元胞体主要集中的部位之一)和蓝斑(脑内去甲肾上腺素能神经元胞体主要集中的部位之一)与应激镇痛的关系。 用新生大鼠腹腔注射谷氨酸-钠的方法损毁弓状核后,用海人酸和电解两种方法损毁中缝背核或蓝斑后,应激镇痛效应均明显减弱。由于谷氨酸-钠和海人酸只选择性地损毁神经元胞体,故认为脑内的β-内啡肽能神经元、5-羟色胺能神经元和去甲肾上腺素能神经元均参与应激的行为镇痛。  相似文献   
943.
Seven pigeons were trained to discriminate without errors between a green keylight and a dark key. The key-pecking response was reinforced in the presence of green, and extinction was in effect in the presence of the dark key. The opportunity to attack a restrained target pigeon was present only during extinction. Both variable-interval 30-sec and fixed-ratio 1 schedules of reinforcement during the positive stimulus induced a higher rate of attack during extinction than a variable-interval 5-min schedule. The highest rate of attack during extinction occurred during the first 20 sec after the positive stimulus terminated. Hence, the withdrawal of the positive condition, rather than the consequences of the pecking response during extinction, appears to be one of the primary factors responsible for attack between pigeons during extinction. Behavioral contrast, defined as a decrease in the rate of responding when the positive stimulus was presented alone, was obtained from the four birds that displayed the lowest overall rates of attack while the three birds with the highest attack rates did not display behavioral contrast. For the birds without contrast, components of the attack response during the positive stimulus presumably competed with and reduced the rate of pecking the key, thereby recluding behavioral contrast.  相似文献   
944.
945.
Lever pressing by rhesus monkeys was maintained by morphine injections during four equally spaced sessions each day. During other periods, lever pressing was maintained by timeout from a continuous naloxone infusion (escape), or by timeout from a stimulus that preceded naloxone injections, or termination of the injections (avoidance-escape). As naloxone dose increased in the escape procedure, response rate increased to a maximum and then decreased. In the avoidance-escape procedure, response rate generally increased as naloxone dose increased, but the changes in rate were small compared to the excape procedure. Substitution of saline for naloxone in the escape procedure led to a very low response rates within three sessions. In the avoidance-escape procedure, rate decrements produced by saline substitution appeared to be related to the behavioral history of the monkey. Previous escape experience led to more rapid decreases in responding when saline was introduced, whereas responding was maintained for 15 sessions in a monkey without prior escape conditioning. Morphine pretreatment produced comparable, dose-dependent decreases in response rates in both procedures. The rate-decreasing effects of morphine were exacerbated when no naloxone was delivered in the escape procedure.  相似文献   
946.
Rats bar pressed for food on a reinforcement schedule in which every response was reinforced, even though a dish of pellets was present. Initially, auditory and visual stimuli accompanied response-produced food presentation. With stimulus feedback as an added consequence of bar pressing, responding was maintained in the presence of free food; without stimulus feedback, responding decreased to a low level. Auditory feedback maintained slightly more responding than did visual feedback, and both together maintained more responding than did either separately. Almost no responding occurred when the only consequence of bar pressing was stimulus feedback. The data indicated conditioned and sensory reinforcement effects of response-produced stimulus feedback.  相似文献   
947.
Pigeons were trained on a modified three-key matching-to-sample procedure, in which only one comparison key (rather than two) was lighted after an observing response to the center-key standard. Pecks on keys of matching comparison hues were reinforced. When non-matching hues appeared as the initially lighted comparisons, the nonmatching hue terminated and the matching hue appeared on the other side key only if the pigeon did not peck the nonmatching comparison for 4.8 sec. Pecks to the nonmatching hue reset the 4.8-sec delay interval. Three hues were used during acquisition. During transfer tests, two novel hues were substituted individually or together for one or two of the training hues. Latencies to the novel side-key hue were shortest when a novel matching hue appeared as the standard on the center key, and were essentially identical to baseline matching latencies. In contrast, when a novel hue appeared as either a standard or comparison in a nonmatching combination, latencies increased with increasing separation between the noevel hue and the nonmatching hue. These transfer data demonstrate the concept of hue matching.  相似文献   
948.
Two groups of six rats received discrimination training with two auditory stimuli differing in intensity. During one stimulus, the schedule was variable interval; during the other, it was either variable time or extinction. Both the variable time and extinction schedules resulted in differential rates of responding in the presence of the two stimuli. Extinction resulted in an earlier and more stable difference. Stimulus generalization gradients obtained along the noise-intensity dimension revealed peak shift with both procedures. In addition, a secondary peak to stimuli in between the two training stimuli occurred with the variable-time schedule.  相似文献   
949.
Animal psychophysics: improvements in the tracking method.   总被引:2,自引:2,他引:0       下载免费PDF全文
It is difficult to maintain stimulus control in animal psychophysical studies using the tracking method. Loss of stimulus control is characterized by wandering thresholds and responses in the absence of the stimulus. Rats were trained to make a variable number of licking responses to turn on an auditory stimulus. A response on a lever in the presence of the stimulus was reinforced with food. Two precedures were added to improve stimulus control. First, lever responses in the absence of the stimulus raised the intensity of the stimulus at the next presentation; second, rate of reinforcement in the threshold region was maintained at about the same level as that in the suprathreshold region by reducing the number of licking responses required to turn on the stimulus. Using these two procedures, stimulus control was improved and maintained and reliable auditory intensity thresholds were obtained.  相似文献   
950.
Harlow (1971) observed that all-female college audiences responded to a pictured infant rhesus monkey with an “ecstasy response,” while males were “completely unresponsive,” and females in coeducational audiences “inhibited the ecstasy response,” explaining these differences in terms of innate sex differences. The present study compared college students' self-reported attraction to pictures of 15 infant and adult nonhuman primates under several conditions. Infant pictures were of two types: infants which were engaged in typical infant behaviors (Infant Behavior), and those which were not (Infant). Subjects made judgments in same- or mixed-sex groups and reported degree of attraction publicly or privately. Ratio scores were used to represent each subject's attraction to infant or infant-behavior pictures compared with his or her attraction to pictures of adults. There were no significant sex differences in attraction to infant or infant-behavior pictures, and sex did not interact with any other variable. However, situational variables significantly affected the response. Males as well as females reported greater attraction to infant and infant-behavior pictures when they viewed the pictures in same-sex compared with mixed-sex groups. Both sexes reported greater attraction to infant and infant-behavior pictures privately than publicly.  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