全文获取类型
收费全文 | 28735篇 |
免费 | 503篇 |
国内免费 | 5篇 |
专业分类
29243篇 |
出版年
2019年 | 304篇 |
2018年 | 420篇 |
2017年 | 460篇 |
2016年 | 508篇 |
2015年 | 513篇 |
2014年 | 535篇 |
2013年 | 2495篇 |
2012年 | 877篇 |
2011年 | 859篇 |
2010年 | 636篇 |
2009年 | 623篇 |
2008年 | 758篇 |
2007年 | 738篇 |
2006年 | 658篇 |
2005年 | 603篇 |
2004年 | 554篇 |
2003年 | 539篇 |
2002年 | 551篇 |
2001年 | 804篇 |
2000年 | 775篇 |
1999年 | 596篇 |
1996年 | 289篇 |
1995年 | 277篇 |
1992年 | 499篇 |
1991年 | 540篇 |
1990年 | 502篇 |
1989年 | 480篇 |
1988年 | 501篇 |
1987年 | 453篇 |
1986年 | 453篇 |
1985年 | 451篇 |
1984年 | 403篇 |
1983年 | 347篇 |
1982年 | 298篇 |
1981年 | 294篇 |
1980年 | 274篇 |
1979年 | 440篇 |
1978年 | 339篇 |
1977年 | 317篇 |
1976年 | 303篇 |
1975年 | 375篇 |
1974年 | 446篇 |
1973年 | 436篇 |
1972年 | 317篇 |
1971年 | 307篇 |
1970年 | 303篇 |
1969年 | 275篇 |
1968年 | 380篇 |
1967年 | 338篇 |
1966年 | 322篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
162.
An analysis of some sensitizing agents in the pathogenesis of stress-induced gastric erosive disease
B. H. Natelson M. Ferrara-Ryan D. Creighton J. Yavorsky G. Curtis W. N. Tapp 《Integrative psychological & behavioral science》1984,19(4):195-199
Prior surgical implantation of a venous catheter sensitized rats to coldimmobilization stress. Three of six catheterized females succumbed during the stress. The remaining rats fell into two groups in terms of their core temperature at the end of the stress period: Male uncatheterized rats had higher temperatures than rats in the other three groups. No relation was found between catheter patency and magnitude of hypothermia. Degree of gastric disease paralleled the core temperature findings in that the male uncatheterized rats had significantly fewer gastric erosions than the rats in the other three groups. Additionally, a robust effect of gender was found with uncatheterized females showing more hypothermia and more gastric disease than uncatheterized males. A subsequent experiment was conducted to evaluate whether anesthesia or wearing the protective spring was responsible in part for the sensitization seen. Here, the gender difference was less although females consistently averaged lower core temperatures after stress than did males. Despite similar core temperatures after stress, females that were prepared with the protective spring apparatus developed more gastric disease than female controls or similarly treated males. Thus, the additional sensitization exhibited by females in the first experiment may relate to the fact that both catheterization and the taping procedure were sensitizers while only catheterization was a sensitizer for males. 相似文献
163.
Rutherford B. Porter 《Journal of School Psychology》1984,22(3):223-231
This report relates personal experiences as they influenced the emerging role of the school psychologist, especially in Pennsylvania and Indiana from 1930 to 1970. 相似文献
164.
165.
166.
Three studies compared the efficacy of various treatments for public-speaking incompetence. These effects were evaluated for the target behavior as well as for generalization effects across situations (conversations), settings (different sizes and types of audiences) and time (6-month follow-up). The first study showed that Self-instructional Training, either alone or in combination with other procedures, produced little or no benefits. The second study demonstrated the superiority of a Skills Training program over flooding therapy, while the final study failed to detect any enhancement of treatment benefits for the addition of home-practice to the Skills Training. In the first two studies generalization occurred across the three dimensions (settings, situations and time), while in the final study it was shown that the program was effective for a clinical population as well as recruited volunteers. 相似文献
167.
Objects, parts, and categories 总被引:5,自引:0,他引:5
Concepts may be organized into taxonomies varying in inclusiveness or abstraction, such as furniture, table, card table or animal, bird, robin. For taxonomies of common objects and organisms, the basic level, the level of table and bird, has been determined to be most informative (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Psychology, linguistics, and anthropology have produced a variety of measures of perception, behavior, and communication that converge on the basic level. Here, we present data showing that the basic level differs qualitatively from other levels in taxonomies of objects and of living things and present an explanation for why so many measures converge at that level. We have found that part terms proliferate in subjects' listings of attributes characterizing category members at the basic level, but are rarely listed at a general level. At a more specific level, fewer parts are listed, though more are judged to be true. Basic level objects are distinguished from one another by parts, but members of subordinate categories share parts and differ from one another on other attributes. Informants agree on the parts of objects, and also on relative "goodness" of the various parts. Perceptual salience and functional significance both appear to contribute to perceived part goodness. Names of parts frequently enjoy a duality not evident in names of other attributes; they refer at once to a particular appearance and to a particular function. We propose that part configuration underlies the various empirical operations of perception, behavior, and communication that converge at the basic level. Part configuration underlies the perceptual measures because it determines the shapes of objects to a large degree. Parts underlie the behavioral tasks because most of our behaviors is indirect toward parts of objects. Labeling appears to follow the natural breaks of perception and behavior; consequently, part configuration also underlies communication measures. Because elements of more abstract taxonomies, such as scenes and events, can also be decomposed into parts, this analysis provides a bridge to organization in other domains of knowledge. Knowledge organization by parts (partonomy) is contrasted to organization by kinds (taxonomy). Taxonomies serve to organize numerous classes of entities and to allow inference from larger sets to sets included in them. Partonomies serve to separate entities into their structural components and to organize knowledge of function by components of structure. The informativeness of the basic level may originate from the availability of inference from structure to function at that level. 相似文献
168.
The present study explored individual differences in performance of a geometric analogies task. Whereas past studies employed true/false or two-alternative items, the present research included four-alternative items and studied eye movements and confidence judgements for each item performance as well as latency and error. Item difficulty proved to be a function of an interaction between the number of response alternatives and the number of elements in items, especially for subjects lower in fluid-analytic reasoning ability. Results were interpreted using two hypothesized performance strategies: constructive matching and response elimination. The less efficient of these, response elimination, seemed to be used more by lower ability subjects on more difficult items. While two previous theories resemble one or the other of these strategies, neither alone seems to capture the complexity of adaptive problem solving. It appears that a comprehensive theory should incorporate strategy shifting as a function of item difficulty and subject ability.Componential models, based in part on past research, revealed that a justification component was activated and deactivated depending upon the nature of the analogy being solved. In addition, two new components, spatial inference and spatial application, were identified as important on some items, suggesting that different geometric analogy items invoke different cognitive processing components. Thus, a comprehensive theory should also describe component activation and deactivation. 相似文献
169.
Dr. Robert Lichtenstein 《Journal of abnormal child psychology》1984,12(1):79-93
Parents of 391 preschool children ages 49 to 64 months completed a brief developmental inventory as part of a preschool screening program operated by an urban school district. The 28-item developmental inventory assessed adaptive behavior and language development. In addition, preschool children were administered the Minneapolis Preschool Screening Instrument. Teacher ratings of kindergarten performance the following year provided criterion data to validate the screening measures. Correlations with the overall teacher rating [the mean of nine ratings] were .40 for the adaptive behavior scale and .57 for the language scale. Validity figures for the developmental inventory were significantly higher for low SES than for high SES children, for older children [57 to 64 months] than for younger children [49 to 56 months], and for firstborn children than for younger siblings. No effects were found by sex. While a positive relationship between parent reports of developmental functioning and early school performance was clearly established, validity levels did not justify use of parent information as a sole source of preschool screening information.This research was supported in part by a grant from the Bureau of Education for the Handicapped. 相似文献
170.
Stimulus selection in passive avoidance learning and retention: weanling, periadolescent, and young adult rats 总被引:1,自引:0,他引:1
Periadolescent rats exhibit a number of behavioral differences in comparison with younger or older animals. For instance, periadolescents tend to show enhanced acquisition of simple active avoidance tasks, but impaired acquisition of more complex appetitive and aversive discriminations. In this experiment, rats were trained on a simple passive avoidance task at one of three ages, as weanlings (25 days), periadolescents (35 days), or young adults (45 days). Training occurred in the presence of both a redundant discriminative stimulus and a specified, redundant contextual stimulus. The periadolescents did not differ from either younger or older rats in rate of learning the passive avoidance task. The retention performance of these animals was then tested following a change in either, neither, or both of the redundant cues. When a measure of performance that controls for baseline activity was used, it was observed that periadolescents were not disrupted by a change in the redundant discriminative stimulus, a cue change that clearly disrupted performance in 25- and 45-day-old animals, and tended to be more disrupted by the contextual change than younger or older rats. It is hypothesized that the alterations in performance exhibited by periadolescents may be related to an ontogenetic alteration in stimulus selection modulated by the catecholaminergic systems. 相似文献