全文获取类型
收费全文 | 2257篇 |
免费 | 75篇 |
国内免费 | 2篇 |
出版年
2023年 | 17篇 |
2021年 | 27篇 |
2020年 | 31篇 |
2019年 | 48篇 |
2018年 | 54篇 |
2017年 | 66篇 |
2016年 | 76篇 |
2015年 | 43篇 |
2014年 | 57篇 |
2013年 | 307篇 |
2012年 | 88篇 |
2011年 | 95篇 |
2010年 | 58篇 |
2009年 | 56篇 |
2008年 | 65篇 |
2007年 | 84篇 |
2006年 | 66篇 |
2005年 | 63篇 |
2004年 | 57篇 |
2003年 | 53篇 |
2002年 | 69篇 |
2001年 | 37篇 |
2000年 | 59篇 |
1999年 | 38篇 |
1998年 | 20篇 |
1997年 | 27篇 |
1996年 | 17篇 |
1995年 | 22篇 |
1994年 | 22篇 |
1993年 | 27篇 |
1992年 | 23篇 |
1991年 | 20篇 |
1990年 | 17篇 |
1989年 | 21篇 |
1988年 | 22篇 |
1987年 | 29篇 |
1986年 | 28篇 |
1985年 | 31篇 |
1984年 | 22篇 |
1983年 | 18篇 |
1982年 | 21篇 |
1981年 | 28篇 |
1980年 | 24篇 |
1979年 | 26篇 |
1978年 | 22篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1975年 | 19篇 |
1974年 | 29篇 |
1973年 | 26篇 |
排序方式: 共有2334条查询结果,搜索用时 31 毫秒
941.
The brain peptide, vasopressin (VP), was studied with respect to its effects on maternal care in rearing natural and cross-fostered
pups. Long-Evans (LE) rats synthesize hypothalamic VP; whereas, Brattleboro (DI) rats do not produce this peptide. Long-Evans
dams exhibited superior maternal care when compared with DI dams when rearing their own as well as foster pups. This enhanced
behavior was evidenced by the higher survival rate of pups reared by LE mothers compared to those reared by DI mothers. Later,
when the offspring were subjected to the stress of 23 hours of food restriction each day, LE animals reared by their natural
mothers survived for a significantly longer period of time and developed significantly less stomach pathology than DI animals
reared by their natural mothers or LE foster mothers. The results demonstrated that the secondary factor of maternal care
in the absence of VP was of little consequence in the characteristic difficulties observed in DI offspring. 相似文献
942.
The brain peptide, vasopressin (VP), was studied with respect to its effects on maternal care in rearing natural and cross-fostered
pups. Long-Evans (LE) rats synthesize hypothalamic VP; whereas, Brattleboro (DI) rats do not produce this peptide. Long-Evans
dams exhibited superior maternal care when compared with DI dams when rearing their own as well as foster pups. This enhanced
behavior was evidenced by the higher survival rate of pups reared by LE mothers compared to those reared by DI mothers. Later,
when the offspring were subjected to the stress of 23 hours of food restriction each day, LE animals reared by their natural
mothers survived for a significantly longer period of time and developed significantly less stomach pathology than DI animals
reared by their natural mothers or LE foster mothers. The results demonstrated that the secondary factor of maternal care
in the absence of VP was of little consequence in the characteristic difficulties observed in DI offspring. 相似文献
943.
Helen Morris Cartwright 《Synthese》1993,96(2):201-254
944.
This research compares the relative effectiveness of imported and indigenous measures of personality perception for Hong Kong Chinese. The first study reports on the extraction of six factors of self-perception using bipolar, adjective rating scales from the U.S.A. tapping the Big Five (Digman, 1990), and Openness to Experience (McCrae & Costa, 1985; 1987). The second study reports on the extraction of six factors of self-perception derived from scales developed indigenously by Chinese psychologists. In the third study, the overlap of the imported and the indigenous dimensions is examined, and their relative power in explaining various criterion measures is assessed. The imported factors adequately explained all but one of the indigenous factors, although in complex combinations. Neither scale was better than the other in predicting the criterion variables. Imported measures may cut the phenomenal world differently from indigenous measures, but still enable scientists to predict behaviours just as effectively. In consequence, if replicated with other criterion variables, the present results would challenge the investment required to develop local instrumentation on scientific grounds. 相似文献
945.
946.
Summary This paper explores age-related performance variability, both within trials and between sessions, in repetitive hopping. The mean, the standard deviation (SD), and the coefficient of variation (CV) of several timing and ground-reaction-force variables of hopping were analysed by repeated-measures ANOVA for age-related effects across test sessions and foot used. Forty-five subjects in five age groups (3–4 years, 4–5 years, 6–7 years, 8–9 years, or Adult) performed self-paced, one-footed hopping on three occasions within one week. As was expected, the results showed main effects for Age in all force and time variables, with the exception of CV of medio-lateral force. No significant main effects for Feet were revealed. However, significant Feet x Session interactions were found in flight-time measures, with higher flight-time SD and lower CV for the non-preferred foot in Session 1, a reversal in Session 2, and a negligible difference in Session 3. Across sessions, decreased SD and CV for both vertical and medio-lateral force and shorter flight time indicated more efficient hopping. Overall, it was concluded that SD and CV measures were more sensitive measures of children's performance across repeated sessions than were mean scores and that the order of testing the limbs is an important consideration in experimental protocols when lateralized tasks are measured. 相似文献
947.
This research explores the work perceptions, both physical and mental, of women. The research finds that women's perceptions of waged and nonwaged labor differ greatly depending on the work environment. Perceptions of physical demands of waged labor are almost solely dependent on the type of paid labor women engage in. For homeworkers, perceptions of physical labor are influenced primarily by the number of hours invested in housework. The mental demands of waged and nonwaged labor are also perceived differently. Women in the waged economy report significantly higher mental demands than do homeworkers. This too varies across labor segments. The closest parallel between physical and mental demand perceptions is between homeworkers and women in the service sector of the waged economy. Overall the assumption that women perceive their work roles in the waged market and the home market similarly is negated. 相似文献
948.
Factors influencing the selection of toys for handicapped and normally developing preschool children 总被引:1,自引:0,他引:1
Factors influencing the selection and purchase of toys for children's use were investigated. Subjects were 73 parents or adult friends of normally developing or handicapped preschool children. In addition to providing demographic information about themselves, the subjects rated the importance of 17 factors influencing their selection and purchase of toys. Contrary to previous research, the sex of the child was reported to be of only minor importance in toy selection, as was the picture on the toy package. Two factors, safety and teaching new skills, were rated as extremely important. There were no significant differences in ratings as a result of sex, ethnicity, or whether or not the subjects were parents of a handicapped child. The findings suggest a substantial degree of agreement among parents about what they consider important when choosing toys for children. 相似文献
949.
D Fucci L Petrosino D Harris E Randolph-Tyler S Wagner 《Perception & psychophysics》1989,46(3):275-278
The purpose of the present study was to determine if lingual vibrotactile threshold shifts occurred during magnitude-estimation scaling of suprathreshold stimuli presented to the dorsal surface of the tongue. Possible relationships of the lingual vibrotactile threshold shifts to suprathreshold stimulus intensity, magnitude-estimation responses, and overall scaling behavior were explored. A single group of 24 subjects with an age range of 18 to 22 years participated in this study. Each subject performed two magnitude-estimation tasks. In one of the tasks, threshold of sensitivity was determined after every suprathreshold numerical response of the subject. If a threshold shift was recorded, threshold was allowed to return to the pretest baseline level before continuing to the next suprathreshold stimulus presentation. The results showed that threshold shift did occur during lingual vibrotactile magnitude-estimation scaling, and that it was related to suprathreshold stimulus intensity. The results also showed that the numerical magnitude-estimation responses of the subjects were different for the two scaling tasks. Overall scaling behavior of the subjects in the form of power-function exponents was not different for the two tasks. 相似文献
950.
Holmes HB 《希帕蒂亚:女权主义哲学杂志》1989,4(2):156-168
Problems with clinical research that create conflicts between doctors’ therapeutic and research obligations may be fueled by a rigid view of science as determiner of truth, a heavy reliance on statistics, and certain features of randomized clinical trials. 1 suggest some creative, feminist approaches to such research and explore ways to provide choice for patients and to use values in directing both therapy and science — to enhance the effectiveness of each. 相似文献