全文获取类型
收费全文 | 220222篇 |
免费 | 9339篇 |
国内免费 | 157篇 |
出版年
2020年 | 2848篇 |
2019年 | 3524篇 |
2018年 | 4207篇 |
2017年 | 4556篇 |
2016年 | 5093篇 |
2015年 | 4009篇 |
2014年 | 4881篇 |
2013年 | 23818篇 |
2012年 | 6228篇 |
2011年 | 5889篇 |
2010年 | 4711篇 |
2009年 | 5195篇 |
2008年 | 5781篇 |
2007年 | 5502篇 |
2006年 | 5549篇 |
2005年 | 5347篇 |
2004年 | 4846篇 |
2003年 | 4426篇 |
2002年 | 4259篇 |
2001年 | 5434篇 |
2000年 | 5195篇 |
1999年 | 4478篇 |
1998年 | 3053篇 |
1997年 | 2879篇 |
1996年 | 2784篇 |
1995年 | 2576篇 |
1994年 | 2528篇 |
1993年 | 2495篇 |
1992年 | 3719篇 |
1991年 | 3510篇 |
1990年 | 3392篇 |
1989年 | 3191篇 |
1988年 | 3155篇 |
1987年 | 3087篇 |
1986年 | 3134篇 |
1985年 | 3361篇 |
1984年 | 3162篇 |
1983年 | 2848篇 |
1982年 | 2595篇 |
1981年 | 2551篇 |
1980年 | 2394篇 |
1979年 | 3047篇 |
1978年 | 2611篇 |
1977年 | 2474篇 |
1976年 | 2329篇 |
1975年 | 2667篇 |
1974年 | 2846篇 |
1973年 | 2820篇 |
1972年 | 2342篇 |
1968年 | 2253篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Attribution questionnaires were completed by 137 students in an introductory economics course immediately preceding the first exam in their class and immediately after their exams were returned. Results indicate that males and females used attributions differently, although not as a function of perceived outcome. In contrast, sex-typing groups varied their attribution as a function of perceived outcome. Self-esteem is proposed as a possible mediating variable. It was concluded that sex typing in relation to perceived successful and unsuccessful performance is an important variable in attributional research. 相似文献
972.
Bernard E. Whitley Jr. 《Sex roles》1988,19(9-10):619-638
This study examined the relations of gender and three aspects of gender roles — self concept, behavior, and sexual attitudes — to three aspects of sexual behavior — sexual experience, reasons for intercourse, and contraceptive use. Gender was strongly related to all three aspects of sexual behavior. For both men and women, sex role behaviors were related to sexual experience and to reasons for intercourse, but not to contraceptive use, and sex role self-concept was unrelated to any of the aspects of sexual behavior. The results indicate that sexual behavior is influenced both by societal gender role norms and by individual differences in the acceptance of those norms. 相似文献
973.
Within two weeks of the explosion of the space shuttle Challenger, 188 subjects rated and ranked questionnaire items, and completed open-ended questions reporting their responses to and concerns arising from the accident. Analysis of open-ended responses showed females focused more on communal, person-centered aspects of the tragedy than did males. Analysis of ratings showed females viewed person-oriented issues as more important than did males. However, males and females did not differ in rankings assigned the items nor in ratings of the importance of the technological issues. Claims about sex differences in moral orientation are discussed in light of the results of this study. 相似文献
974.
This article explores how the sales budget is set in a business organization. Findings from a longitudinal participant observation study revealed that the sales budget is considered of great importance to the organization as sales estimates serve as premises for planning of production and supply and new product developments. It was observed that the sales budget was based on a narrow, inner-directed perspective, almost looking away from important environmental driving forces such as competitors and customers. The findings also showed that individuals involved in the sales budgeting process behaved opportunistically, influencing the budgetary process and outcomes. Theoretical and normative implications are highlighted. 相似文献
975.
Multiattribute analysis depends on measurement of values and weights. Unless these measures reflect the decision maker's true values and weights, the multiattribute formula may put a less-preferred alternative in first place. To avoid such disordinality requires stringent measurement conditions: First, the values and weights must be on linear (equal interval) or ratio (known zero) scales. Second, these scales must satisfy a condition of common unit across disparate attribute dimensions. Most methods of range adjustment beg both of these measurement questions. Functional measurement theory can solve both problems and so can be useful in multiattribute analysis. Past work has established the operation of a general cognitive algebra as an empirical reality. The averaging model, in particular, makes possible the definition and estimation of weights and values as distinct psychological parameters. It can also solve the problem of common unit. Cognitive algebra thus provides a grounded theoretical foundation on which to develop self-estimation methodology, in which decision makers provide direct estimates of their values and weights. The logic is straightforward. Functional measurement can analyze global judgments to obtain validated psychological scales. These scales may then be used as validational criteria for the self-estimates. Procedures to eliminate biases in the self-estimates can thus be tested and refined in well-learned multiattribute tasks, such as judgments of meals, in which global judgments are trustworthy. Once developed, such self-estimation procedures may be used with some confidence for general multiattribute analysis. A number of studies from 20-odd years of work on the theory of information integration are summarized to show good, although not unmixed promise for self-estimation. 相似文献
976.
When branches of a fault tree are pruned, subjects do not fully transfer the probability of those branches to the ‘all other’ category. This underestimation of the catch-all probability has been interpreted as an ‘out of sight, out of mind’ form of the availability bias. The present work replicates this underestimation bias with professional managers. It then demonstrates the effectiveness of a corrective tactic, extending the tree by generating additional causes, and also reveals that more easily retrieved short-term causes dominate the generation process. These results do not differ across managers' culture, education or experience. After evaluating such alternative explanations as category redefinition, we conclude that availability is a major cause, though possibly not the sole cause, of the underestimation bias. 相似文献
977.
J P Ricker J Hirsch 《Journal of comparative psychology (Washington, D.C. : 1983)》1988,102(3):203-214
Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II greater than III greater than X for the negatively geotactic (high) line and X greater than III greater than II for the positively geotactic (low) line. When reversing selection for the now phenotypically stable high and low lines and then repeatedly relaxing the reversals, a new genetic homeostasis in the low line was indicated by the return of the reversed-line average scores towards the low extreme; that is, the low line has attained a stable equilibrium for positive geotaxis, an uncharacteristic behavior and an effect not seen before 1979. This change suggests the recent evolution of a new coadaptation among genes. Although not as conclusive, a similar genetic interpretation is suggested for the high line. 相似文献
978.
G M Harrington 《Journal of comparative psychology (Washington, D.C. : 1983)》1988,102(4):400-407
Controversy abounds over attributing group differences on tests to nature, nurture, or test bias. Limitations of correlational sampling from natural populations necessitate experimental methods to resolve underlying issues. In classical psychometrics test items are selected from a larger item pool through analysis of item responses in a sample of subjects. Rats of six inbred strains (n = 366) were tested in multiple mazes to provide a large item pool. Six populations were created, each with differing proportions of each strain. Items selected through independent item analyses within each population yielded six tests. An independent cross-validation sample (n = 146) provided scores on all six tests. This sample was also tested in another set of maze problems defined as the criterion to be predicted. Strain means and intrastrain predictive validities for the six tests varied with strain representation in the population used for item selection (p less than .001). Conventional item-selection procedures clearly produced two forms of minority test bias. 相似文献
979.
J L Gariépy K E Hood R B Cairns 《Journal of comparative psychology (Washington, D.C. : 1983)》1988,102(4):392-399
This research was designed to investigate development and behavioral mediation in lines of ICR mice that have been selectively bred for aggressive behavior. General behavioral reactivity and behavioral immobility have been implicated as potential mediators by prior analyses of preattack interactions. To evaluate the separate roles of these dispositions, the emergence of attacks in genetically selected lines was tracked for 11 years by three levels of analysis: over successive generations, over development, and over dyadic interactions. Convergent outcomes were observed in all three levels with respect to two findings: (a) Robust line differences were obtained in attack behaviors, and (b) strong associations were found between line differences in attacks and line differences in behavioral immobility. Conversely, all three levels of analysis indicated a weak and inconsistent association between line differences in attacks and measures of social and nonsocial reactivity. 相似文献
980.
U W Huck R D Lisk E J Parente 《Journal of comparative psychology (Washington, D.C. : 1983)》1988,102(4):388-391
After 12-15 ejaculatory series, each consisting of several short intromissions (2- to 3-s vaginal penetration) and an ejaculation, male golden hamsters adopt an altered copulatory pattern consisting of long intromissions (5- to 25-s penetration with intravaginal thrusting). Receptivity declines and the tendency for the female to attack the male increases at about the time of this shift in copulatory pattern. Because the mean interintromission interval (III) between short intromissions is about 8 s compared to 100 s between long intromissions, it is possible that females detect this difference and adjust their mating accordingly. When the III between short intromissions from a rested male was experimentally increased to 100 s by use of a halter and lead device, the duration of lordosis was significantly less than that displayed by females paired with control males (8-s III) and virtually the same as that displayed by females paired with males that produced only long intromissions. This suggests that the female uses the temporal patterning of intravaginal stimulation as one criterion for terminating mating with a particular male. 相似文献