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   75859篇
  免费   3045篇
  国内免费   30篇
  2020年   823篇
  2019年   962篇
  2018年   1397篇
  2017年   1412篇
  2016年   1486篇
  2015年   1060篇
  2014年   1313篇
  2013年   6261篇
  2012年   2390篇
  2011年   2439篇
  2010年   1500篇
  2009年   1511篇
  2008年   2170篇
  2007年   2084篇
  2006年   1934篇
  2005年   1625篇
  2004年   1658篇
  2003年   1598篇
  2002年   1571篇
  2001年   2384篇
  2000年   2243篇
  1999年   1715篇
  1998年   837篇
  1997年   761篇
  1996年   809篇
  1995年   743篇
  1992年   1468篇
  1991年   1361篇
  1990年   1331篇
  1989年   1273篇
  1988年   1257篇
  1987年   1181篇
  1986年   1209篇
  1985年   1239篇
  1984年   1035篇
  1983年   898篇
  1979年   1092篇
  1978年   843篇
  1977年   701篇
  1976年   709篇
  1975年   878篇
  1974年   1036篇
  1973年   1091篇
  1972年   898篇
  1971年   857篇
  1970年   776篇
  1969年   790篇
  1968年   975篇
  1967年   880篇
  1966年   867篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Many counselors are currently undergoing a Kuhnian paradigm shift from linear models of behavioral problem conceptualization to systemic conceptual models. As a result, it has become incumbent on counselor-educators to introduce the systems concept of family therapy to their students within a framework that renders it meaningful not only intellectually but also practically. This paper presents one way of doing this successfully with master's level counselors-in-training who have no live families on which to practice. An overview of systems approaches to family therapy is presented along with a seven-stage supervision approach for teaching structural/strategic therapy in limited situations where the supervision of live families is not practical or possible.  相似文献   
922.
923.
Six pigeons were exposed to concurrent variable-interval schedules in which the programmed reinforcer ratios changed from session to session according to a pseudorandom binary sequence. This procedure corresponded to the stochastic identification paradigm (“white-noise experiment”) of systems theory and enabled the relation between log response ratios in the current session and log reinforcer ratios in all previous sessions to be determined. Such dynamic relations are called linear transfer functions. Both nonparametric and parametric representations of these, in the form of “impulse-response functions,” were determined for each bird. The session-to-session response ratios resulting from the session-to-session pseudorandom binary variations in reinforcer ratios were well predicted by the impulse-response functions identified for each pigeon. The impulse-response functions were well fitted by a second-order dynamic model involving only two parameters: a time constant and a gain. The mean time constant was 0.67 sessions, implying that the effects of abrupt changes in log reinforcer ratios should be 96% complete within about five sessions. The mean gain was 0.53, which was surprisingly low inasmuch as it should equal the sensitivity to reinforcement ratio observed under steady-state conditions. The same six pigeons were subjected to a similar experiment 10 months following the first. Despite individual differences in impulse-response functions between birds within each experiment, the impulse-response functions determined from the two experiments were essentially the same.  相似文献   
924.
Pigeons keypecked on a two-key procedure in which their choice ratios during one time period determined the reinforcement rates assigned to each key during the next period (Vaughan, 1981). During each of four phases, which differed in the reinforcement rates they provided for different choice ratios, the duration of these periods was four minutes, duplicating one condition from Vaughan's study. During the other four phases, these periods lasted six seconds. When these periods were long, the results were similar to Vaughan's and appeared compatible with melioration theory. But when these periods were short, the data were consistent with molecular maximizing (see Silberberg & Ziriax, 1982) and were incompatible with melioration, molar maximizing, and matching. In a simulation, stat birds following a molecular-maximizing algorithm responded on the short- and long-period conditions of this experiment. When the time periods lasted four minutes, the results were similar to Vaughan's and to the results of the four-minute conditions of this study; when the time periods lasted six seconds, the choice data were similar to the data from real subjects for the six-second conditions. Thus, a molecular-maximizing response rule generated choice data comparable to those from the short- and long-period conditions of this experiment. These data show that, among extant accounts, choice on the Vaughan procedure is most compatible with molecular maximizing.  相似文献   
925.
The effects of electroconvulsive shock (ECS) on spatial memory first reported by Shavalia, Dodge, and Beatty (1981, Behavioral and Neural Biology, 31, 261-273) were systematically replicated in two experiments. Rats acquired concurrent spatial memories in two 8-arm radial mazes. Each rat was allowed four choices in Maze 1 and then, after 2 h, four choices in Maze 2. After 2 h each rat was tested for retention in Maze 1 and, after 2 more h, was tested for retention in Maze 2. A single ECS was administered immediately after the fourth choice in Maze 2. Retention (as measured by accuracy of Choices 5-8) was diminished for Maze 1 but not for Maze 2. In the second experiment, the delay between the retention tests was eliminated (thus holding the ECS-Choice 5 interval constant for the two mazes). Once again retention of Maze 1 was impaired and retention of Maze 2 was spared; that finding suggests that ECS does not proactively affect radial-arm maze performance. The results of a third experiment converge on the same conclusion; ECS failed to reduce levels of spontaneous alternation. Therefore, ECS appears to interfere retroactively with relatively old spatial memories and newly established memories appear to be immune to the amnestic effects of ECS. Implications and various explanations are considered.  相似文献   
926.
The present experiment used hippocampal stimulation to determine the temporal gradient of consolidation of spatial working memory. Rats were trained to perform a spatial working memory task on a radial maze with 12 arms. Each rat went to the ends of 6 arms to obtain a food reward. After 8 h, the rat chose among all the arms to find the ones not previously chosen (and consequently still having food). During some test sessions, the hippocampus was stimulated electrically either at a current level just high enough to produce an electrophysiological seizure, or at a current level below this seizure threshold. Stimulation occurred at one of five intervals (0 to 8 h) following the completion of the first six choices. During other test sessions, the hippocampus was not stimulated. After seizure stimulation, the number of retroactive errors (returning to arms chosen prior to stimulation) increased at all delay intervals; the number of proactive errors (returning to arms chosen after stimulation) increased only with the delay of 8 h. Subthreshold stimulation had no influence on either type of error. These results indicate that normal hippocampal function is required for the maintenance of spatial information in working memory, and that the time course of consolidation of this information is significantly greater than that seen in other types of memory, or consolidation may not take place at all.  相似文献   
927.
Training and Research in Counselling   总被引:1,自引:0,他引:1  
Formal counselling training in Britain began with the preparation of school counsellors in universities and relied largely upon American models. Early courses were highly didactic but over the last decade practical and experiential aspects have taken precedence. Basic counselling training has now been extended into the preparation of many workers, voluntary and professional. Counselling research also had academic origins, but has broadened to include many different work settings. Much of the published research has been in the form of surveys of counselling services, but some detailed studies of process are noted. There is a need for research to be increased, and the gap between research and practice shortened, if counselling is to demonstrate its relevance to contemporary needs.  相似文献   
928.
To increase understanding of the relationships between gender and causal attributions, dispositional and situational variables were examined to determine if they affected causal attributions differently if the subjects were females or males. Four dispositional variables—locus of control, neuroticism, achievement motivation, and self-esteem—and five situational variables—expectancy of success, self-reported commitment, perceived productivity, perceived task complexity, and actual performance—were examined for their moderating effects on the gender-causal attributional relationships. The dispositional variables did not moderate any causal relationships. By comparison, four situational variables—performance, commitment, productivity, and complexity—moderated at least one of the gender-attribution relationships. It was concluded that more attention should be directed to the identification of situational moderators.  相似文献   
929.
Michael W. Martin 《Sex roles》1985,13(11-12):597-605
The relative effects of equity, equality, and reward level upon assessments of marital satisfaction are investigated. In doing so, the impact of gender-role orientation upon the relationship between the predictor variables and marital satisfaction is specified. The data indicate that reward level is the major variable affecting assessments of satisfaction for both moderns and traditionals. Further, the effect of reward level is more pronounced for those with modern gender-role orientations. Contrary to expectation, the effects of the exchange-related variables, equity and equality, are minimal for both moderns and traditionals. These findings suggest that intimates, regardless of gender-role orientation, tend to avoid the “bookkeeping” involved in global equity and equality comparisons and instead accentuate individual reward levels. It appears, however, that moderns are significantly more demanding than traditionals in their emphasis upon reward levels.  相似文献   
930.
Do alcoholic Korsakoff's syndrome patients acquire affective reactions?   总被引:1,自引:0,他引:1  
In this study we report two experiments that investigate the acquisition of affective reactions. In Experiment 1, unfamiliar melodies were played to Korsakoff's syndrome patients and alcoholic and nonalcoholic control subjects who were matched with them according to age and education. Following a retention interval of 5 min, subjects received a preference test on old and new melodies. Korsakoff's syndrome patients showed the same increase in preference for old melodies as a consequence of prior exposures as control subjects did, but their recognition of melodies was significantly impaired in comparison with controls. In Experiment 2, the same subjects saw photographs of two men. Fictional biographical information depicted one as a "good guy" and the other as a "bad guy." After a retention interval of approximately 20 days, Korsakoffs recalled virtually none of the biographical information; however, 78% preferred the good guy, and impression ratings were less favorable for the bad guy. Korsakoff patients developed preferences and impressions even though they did not have voluntary access to the information on which the preferences were based. However, their impression ratings were less extreme than those of controls. The pattern of results of the two studies is discussed in terms of Johnson's (1983) MEM 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