全文获取类型
收费全文 | 31179篇 |
免费 | 1342篇 |
国内免费 | 25篇 |
专业分类
32546篇 |
出版年
2020年 | 337篇 |
2019年 | 424篇 |
2018年 | 599篇 |
2017年 | 569篇 |
2016年 | 650篇 |
2015年 | 430篇 |
2014年 | 523篇 |
2013年 | 2418篇 |
2012年 | 997篇 |
2011年 | 992篇 |
2010年 | 587篇 |
2009年 | 655篇 |
2008年 | 846篇 |
2007年 | 863篇 |
2006年 | 761篇 |
2005年 | 671篇 |
2004年 | 649篇 |
2003年 | 597篇 |
2002年 | 622篇 |
2001年 | 1052篇 |
2000年 | 1054篇 |
1999年 | 774篇 |
1998年 | 324篇 |
1997年 | 302篇 |
1995年 | 316篇 |
1992年 | 625篇 |
1991年 | 590篇 |
1990年 | 568篇 |
1989年 | 546篇 |
1988年 | 539篇 |
1987年 | 481篇 |
1986年 | 484篇 |
1985年 | 530篇 |
1984年 | 438篇 |
1983年 | 401篇 |
1982年 | 309篇 |
1979年 | 473篇 |
1978年 | 327篇 |
1977年 | 301篇 |
1976年 | 318篇 |
1975年 | 364篇 |
1974年 | 434篇 |
1973年 | 463篇 |
1972年 | 403篇 |
1971年 | 341篇 |
1970年 | 319篇 |
1969年 | 336篇 |
1968年 | 418篇 |
1967年 | 371篇 |
1966年 | 357篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
901.
Several neural networks were developed inMathematica in order to explore the role of “spiky” neurons in neural network memory simulations. UsingMathematica for this task confirmed its value as a powerful tool for neural network development: It exhibited distinct advantages over other environments in programming ease, flexibility of data structures, and the graphical assessment of network performance. 相似文献
902.
903.
Recent studies suggest that performance attendant on visual word perception is affected not only by feedforward inconsistency (i.e., multiple ways to pronounce a spelling) but also by feedback inconsistency (i.e., multiple ways to spell a pronunciation). In the present study, we provide a statistical analysis of these types of inconsistency for all monosyllabic English words. This database can be used as a tool for controlling, selecting, and constructing stimulus materials for psycholinguistic and neuropsychological research. Such large-scale statistical analyses are necessary devices for developing metrics of inconsistency, for generating hypotheses for psycholinguistic experiments, and for building models of word perception, speech perception, and spelling. 相似文献
904.
Lorraine G. Allan Shepard Siegel Chandani Kulatunga-Moruzi Thomas Eissenberg C. Andrew Chapman 《Attention, perception & psychophysics》1997,59(8):1327-1334
In the typical induction of the orientation-contingent color aftereffect (CCAE), the stimuli are composed of elements that differ in both color and luminance. Three experiments are reported that show that chromatic contrast between stimulus elements is insufficient for the induction of the orientation-CCAE and that luminance contrast is necessary. These experiments expand on previous research concerned with the role of luminance contrast in the induction of orientation-CCAEs by eliminating alternative explanations. 相似文献
905.
In 2 experiments, the effect of active or passive mobility and active or passive choice experiences on children's memory for locations visited while retrieving puzzle pieces hidden in a large room were examined. In the first experiment, fifty-two 6- and 7-year-old children were randomly assigned to 1 of 4 training conditions: active choice-active movement, active choice-passive movement, passive choice-active movement, and passive choice-passive movement. After 3 training trials, all children were tested in the active choice-active movement condition. A 2 (movement) x 2 (choice) factorial multivariate analysis of variance revealed a significant main effect for movement. Children who had moved actively to find the puzzle pieces in the training trials had (a) a greater percentage correct, (b) more correct visits between errors, and (c) a later visit of first error than children who had been passively pushed in a wheelchair. Making active choices in training did not significantly affect performance. A second experiment used identical procedures but tested 32 children with mobility dif-difficulties who regularly used a wheelchair because of either cerebral palsy or spina bifida. Children from this group who moved actively during training to retrieve the puzzle pieces also performed better on testing. Implications of the results for children with disabilities and for developmental theory are discussed. 相似文献
906.
Our research focused on the implicit beliefs of potential brainstormers about the possible outcomes of brainstorming. We conducted four studies to assess the relative importance of quality and quantity as goals of brainstorming. In Study 1, we found evidence for a quality over quantity hypothesis: participants indicated that it was more important to produce creative, original, and high quality ideas than to generate a large number of ideas. In Studies 2 and 3, participants displayed support for the quality over quantity hypothesis by showing in group favoritism for a quality dimension but not a quantity dimension. Study 4 showed that participants believed brain-storming would enhance the quality of others' ideas more than one's own ideas, but they did not display a similar bias about idea quantity. 相似文献
907.
To be competitive in today's job market, many entry-level management candidates are looking to electronic technology to help them find employment. Although technology is an essential part of today's business environment, the findings of this study indicate that very few of the human resource/personnel directors (HR/PD) in the top 100 privately owned companies in Georgia are using electronic technology to fill entry-level managerial positions. These HR/PD, however, view positively those applicants who use electronic methods for job searching and predict that these methods will become a common practice within 2 years. 相似文献
908.
Robert W. Holt Jennifer A. O'Connor Jennifer L. Smith Theodore L. Gessner Timothy C. Clifton Michael D. Mumford 《Journal of applied social psychology》1997,27(9):781-799
This study examined the effects of information about a landlord's personality on juror judgments for a landlord-tenant civil trial. The personality information manipulated was specifically relevant to destructive acts. Alternative versions of witness testimony were used to describe a landlord either high or low on need for power. treating people as objects, and negative life themes. This information strongly influenced aspects of the schema for this case constructed by the individual mock jurors. Destructive personality information caused dislike of the landlord and lowered the credibility of his story. If the landlord treated people as objects, the credibility of the tenant's story and positive evaluations of the tenant increased. Juror judgments about relative fault were strongly shifted by destructive personality information. An empirical model for juror decisions indicated a dynamic interplay of story components and fault judgments. 相似文献
909.
The MMPI-2 is often used for screening job applicants when public safety or security are at risk. Inherent in such applications is concern for profile validity and test defensiveness. In this study, we examine the impact of revised instructions on profile validity for a group of job applicants who initially produced invalid profiles. Participants were 271 male applicants for airline pilot positions. Of these, 72 produced invalid defensive MMPI-2 profiles during preemployment screening. The MMPI-2 was readministered to these applicants with instructions informing them of validity scales and instructing them to respond in a more open, honest manner. Comparisons were made between valid and invalid profiles for initial administrations and between valid and invalid profiles at readministration. Some clinical scales were more elevated for valid, nondefensive profiles. Most content scales showed more elevation for valid profiles, and 12% of the applicants who were retested produced significant elevations (T>or=65) on the content scales. Profiles were similar to those produced by employed pilots of a previous study. 相似文献
910.
Comparing Locomotion With Lever-press Travel In An Operant Simulation Of Foraging 总被引:2,自引:2,他引:0 下载免费PDF全文
An operant model of foraging was studied. Rats searched for food by pressing on the left lever, the patch, which provided one, two, or eight reinforcers before extinction (i.e., zero reinforcers). Obtaining each reinforcer lowered the probability of receiving another reinforcer, simulating patch depletion. Rats traveled to another patch by pressing the right lever, which restored reinforcer availability to the left lever. Travel requirement changed by varying the probability of reset for presses on the right lever; in one condition, additional locomotion was required. That is, rats ran 260 cm from the left to the right lever, made one response on the right lever, and ran back to a fresh patch on the left lever. Another condition added three hurdles to the 260-cm path. The lever-pressing and simple locomotion conditions generated equivalent travel times. Adding the hurdles produced longer times in patches than did the lever-pressing and simple locomotion requirements. The results contradict some models of optimal foraging but are in keeping with McNair's (1982) optimal giving-up time model and add to the growing body of evidence that different environments may produce different foraging strategies. 相似文献