全文获取类型
收费全文 | 66989篇 |
免费 | 2710篇 |
国内免费 | 36篇 |
专业分类
69735篇 |
出版年
2020年 | 748篇 |
2019年 | 928篇 |
2018年 | 1357篇 |
2017年 | 1348篇 |
2016年 | 1433篇 |
2015年 | 988篇 |
2014年 | 1162篇 |
2013年 | 5792篇 |
2012年 | 2126篇 |
2011年 | 2306篇 |
2010年 | 1370篇 |
2009年 | 1380篇 |
2008年 | 2085篇 |
2007年 | 2074篇 |
2006年 | 1847篇 |
2005年 | 1659篇 |
2004年 | 1601篇 |
2003年 | 1530篇 |
2002年 | 1543篇 |
2001年 | 2143篇 |
2000年 | 2026篇 |
1999年 | 1579篇 |
1998年 | 824篇 |
1997年 | 728篇 |
1996年 | 680篇 |
1995年 | 681篇 |
1994年 | 627篇 |
1993年 | 669篇 |
1992年 | 1243篇 |
1991年 | 1185篇 |
1990年 | 1175篇 |
1989年 | 1059篇 |
1988年 | 1043篇 |
1987年 | 1025篇 |
1986年 | 1006篇 |
1985年 | 1062篇 |
1984年 | 888篇 |
1983年 | 768篇 |
1982年 | 637篇 |
1979年 | 869篇 |
1978年 | 663篇 |
1976年 | 624篇 |
1975年 | 776篇 |
1974年 | 832篇 |
1973年 | 834篇 |
1972年 | 719篇 |
1971年 | 630篇 |
1968年 | 728篇 |
1967年 | 677篇 |
1966年 | 609篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Theoretical Medicine and Bioethics - 相似文献
993.
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
994.
Experiments 1 and 2 established children’s (mean age 3 years, 7 months) subject-relative and object-relative motion thresholds at 1°31.37′/sec and 1°9.33′/sec, respectively, speeds well above those found for adults. Experiment 3 established that preschoolers, like adults, attribute object-relative motion to the smaller of two objects, with the inducing properties of the larger stimulus greatest when it is surrounding rather than adjacent to a smaller stimulus. The inducing advantage of surroundedness was equivalent for a single-element square frame and a multielement six-dot frame. 相似文献
995.
996.
A sample of delinquent and nondelinquent male adolescents was assessed with respect to locus of control and intellectual achievement responsibility. Data were also gathered concerning age, family size, birth order, socioeconomic status, race, and school grade. Results were subjected to a multivariate analysis and showed support for a multidimensional model of locus of control. There was no difference in expectancy of control for negative academic events between delinquents and nondelinquents. In general, birth order and delinquency were the two most important determinants of locus of control. Results are discussed in terms of previous literature on locus of control with particular consideration paid to expectations of control. 相似文献
997.
This study assessed the role of adaptive versus maladaptive coping behaviors and personal characteristics in influencing the affective reactions of managers to four role stressors. Maladaptive coping was found to moderate the relationships of several role stressors with felt stress and job satisfaction. Maladaptive coping and trait anxiety also demonstrated independent additive effects on felt stress and job satisfaction over and above that of all four stressors. 相似文献
998.
Three measures of chronic self-esteem, plus four measures developed to assess situational components of self-esteem (task-specific self-esteem and social self-esteem), were administered to 238 undergraduates at a large, urban university and a community college in the southeastern United States. Evidence for a composite construct of self-esteem was found. Results also indicate task-specific self-esteem correlates as high as .42 (p < .01) with chronic self-esteem and as high as .76 (p < .01) with social self-esteem. Task-specific self-esteem was found to be a better predictor of grade point average than chronic or social self-esteem. Suggestions are made for further research on the situational components of self-esteem to extend current findings. 相似文献
999.
The authors recently proposed that adverse effects of material rewards on Wechsler subscale performance may be the result of a reward-produced developmental regression. The present study further explores that idea through an attempt to replicate earlier findings with adults and to extend the inquiry to children. Selected Wechsler subscales were administered to 32 subjects at each of three ages (5, 10, and 18 years) under either reward or nonreward conditions. Subscales were chosen to represent both algorithmic and heuristic types of tasks. Reward and nonreward groups (8 males and 8 females per group at each age) were matched initially on age and ability. For adults, consistent with earlier findings, reward had an adverse effect on performance on the heuristic subscales and tended to facilitate performance on the algorithmic subscales. However, rewards generally had no effect at the fourth-grade level and had a reverse effect at the nursery school level, i.e., rewards facilitated heuristic and hampered algorithmic performance. These findings appear to be more consistent with an explanation based on developmental regression than on any available alternative mechanism. 相似文献
1000.