全文获取类型
收费全文 | 19691篇 |
免费 | 799篇 |
国内免费 | 7篇 |
出版年
2019年 | 272篇 |
2018年 | 352篇 |
2017年 | 333篇 |
2016年 | 364篇 |
2015年 | 236篇 |
2014年 | 352篇 |
2013年 | 1720篇 |
2012年 | 559篇 |
2011年 | 604篇 |
2010年 | 372篇 |
2009年 | 397篇 |
2008年 | 564篇 |
2007年 | 572篇 |
2006年 | 520篇 |
2005年 | 460篇 |
2004年 | 457篇 |
2003年 | 425篇 |
2002年 | 414篇 |
2001年 | 489篇 |
2000年 | 554篇 |
1999年 | 386篇 |
1998年 | 264篇 |
1997年 | 195篇 |
1996年 | 210篇 |
1995年 | 204篇 |
1992年 | 325篇 |
1991年 | 305篇 |
1990年 | 332篇 |
1989年 | 314篇 |
1988年 | 305篇 |
1987年 | 266篇 |
1986年 | 289篇 |
1985年 | 294篇 |
1984年 | 241篇 |
1983年 | 242篇 |
1980年 | 203篇 |
1979年 | 286篇 |
1978年 | 262篇 |
1977年 | 201篇 |
1976年 | 195篇 |
1975年 | 271篇 |
1974年 | 289篇 |
1973年 | 322篇 |
1972年 | 261篇 |
1971年 | 242篇 |
1970年 | 199篇 |
1969年 | 221篇 |
1968年 | 287篇 |
1967年 | 262篇 |
1966年 | 228篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
There is evidence that cardiac arrhythmias are partially of CNS origin, and that certain drugs affect arrhythmia, both positively and negatively, through CNS action. We hypothesized and confirmed that chlordiazepoxide diminished the well-established incidence of arrhythmias (A-V blocks and nodal escapes) in five nervous pointer dogs. It is known that this drug normalizes behavior and aids in the bar-pressing performance of nervous dogs. Nervous dogs tend to have low heart rates (HRs) while normals have higher HRs. Chlordiazepoxide increased HRs in our five nervous dogs, and we postulated that HR increase would be less or none in normals. This was confirmed in a later study of five normals. A further study of eight normal dogs and eight nervous dogs essentially reproduced these findings, suggesting the possibility that the slow heart rates and the behavioral abnormality have a common basis, expected to be some CNS biochemical lesion. 相似文献
942.
Subjects searched for predesignated consonant letters embedded in strings of consonants, consonants and vowels, or consonants and numbers. In Experiments 1-3, detection was quicker in the consonant-vowel and consonant-number strings than in the consonant strings. Apparently, vowels and numbers were less confusable distractors than are nontarget consonants. Experiment 4 tested whether psychophysical or categorical information about letters and numbers enabled subjects to process consonant-vowel and consonant-number strings more quickly. Results indicated that psychophysical characteristics of target and distractor letters mediated both word and nonword superiority effects.
相似文献943.
Janat F. Parker 《International journal of psychology》1977,12(4):243-252
This investigation compared the free recall of concrete and abstract words in American and Ghanaian college students. There were no differences in the total number of words recalled as a function of concreteness or culture. However, recall of concrete words showed a greater improvement across trials for both cultures. Although there was no difference in the amounts of subjective organization exhibited by Ghanaian and American students, there was evidence for a greater serializing tendency among American students. It appears that the major cultural differences typically observed in African-American comparisons of free recall may be overshadowed by increases in the educational level of the subjects. 相似文献
944.
945.
946.
The training of family therapists requires that learning objectives and expectations be specified in empirical terms so that the trainer and trainee can achieve clear goals, identify areas of progress, and meet the special needs of the trainee. This paper articulates the competencies, objectives, and criteria for evaluation used during a time-limited training program for therapists involved in family therapy research conducted at Centennial School of Lehigh University. 相似文献
947.
Open classrooms with few rules, individualized instruction, and informal class organization present new problems for the application of behavior principles. The effects of three types of teacher aides on student achievement and on-task behavior were studied. Each was compared with a standard no-aide condition. Subjects were 54 third graders in two "open"-style classrooms. The three types of aide, helping adult, disciplinary adult, and helping fifth-grade aide, were compared in a multi-element design with a no-aide control. The helping-adult aide significantly affected the academic output of the class, when compared with the no-aide condition. All aide conditions produced more academic work and on-task behavior than did the standard no-aide condition. 相似文献
948.
949.
950.
NORMA F. AUSMUS 《Journal of Employment Counseling》1977,14(2):54-58
In eight states, counselors and people making career choices now have a new tool for getting the information they need. Occupational information systems are delivering up-to-date, accurate information about occupations and local employment conditions in Alabama, Colorado, Massachusetts, Michigan, Minnesota, Ohio, Washington, and Wisconsin. Funded with seed money from the U.S. Department of Labor's National Occupational Information Service, the development of these systems is guided by these key principles: cooperation between producers and users of occupational information; intensive information-development efforts that maximize the use of available information; systematic information delivery; user services, training, and marketing efforts; and cost sharing and eventual self-support. 相似文献