全文获取类型
收费全文 | 1776篇 |
免费 | 127篇 |
出版年
2024年 | 1篇 |
2023年 | 40篇 |
2022年 | 32篇 |
2021年 | 55篇 |
2020年 | 73篇 |
2019年 | 90篇 |
2018年 | 107篇 |
2017年 | 97篇 |
2016年 | 94篇 |
2015年 | 70篇 |
2014年 | 89篇 |
2013年 | 239篇 |
2012年 | 143篇 |
2011年 | 119篇 |
2010年 | 55篇 |
2009年 | 72篇 |
2008年 | 77篇 |
2007年 | 76篇 |
2006年 | 54篇 |
2005年 | 55篇 |
2004年 | 45篇 |
2003年 | 47篇 |
2002年 | 37篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 12篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1973年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有1903条查询结果,搜索用时 15 毫秒
171.
172.
173.
In this paper we analyse how the risks associated with research on transgenic plants are regulated in Sweden. The paper outlines
the way in which pilot projects in the plant sciences are overseen in Sweden, and discusses the international and national
background to the current regulatory system. The historical, and hitherto unexplored, reasons for the evolution of current
administrative and legislative procedures in plant science are of particular interest. Specifically, we discuss similarities
and differences in the regulation of medicine and plant science, and we examine the tendency towards dichotomizing risk —
focusing on social/ethical risks in medicine and biological risks in plant science. The context of this article is the Synpraxia
research project, an inter-disciplinary program combining expertise in sciences and the humanities. 相似文献
174.
DSM-defined anxiety disorders symptoms in South African youths: Their assessment and relationship with perceived parental rearing behaviors 总被引:2,自引:0,他引:2
Muris P Loxton H Neumann A du Plessis M King N Ollendick T 《Behaviour research and therapy》2006,44(6):883-896
This study investigated DSM-defined anxiety symptoms in South African youths. Children and adolescents (N = 701) from various cultural groups completed the SCARED and a questionnaire measuring perceived parental rearing behaviors. Results indicated that the psychometric properties of the SCARED were satisfactory in the total sample of South African youths, and acceptable in colored and black children and adolescents. Further, colored and black youths displayed higher SCARED scores than white youths, and there were also differences in the perceived parental rearing behaviors of the cultural groups. White youths generally rated their parents' rearing behaviors as less anxious, overprotective, and rejective, but more emotionally warm than colored and black youths. Finally, positive correlations were found between anxious rearing, overprotection, and rejection and anxiety symptoms. The clinical and research implications of these findings are briefly discussed. 相似文献
175.
Past research predicts that males will be more likely to withdraw in one-on-one interactions versus groups, whereas females will be more likely to withdraw in groups than in one-on-one interactions. Ninety-eight 10-year-old children engaged in a word generation task either in same-sex dyads or in groups. Boys completed significantly more words in groups than in dyads, whereas girls' performance was similar in the 2 social structures. Confirming the hypothesis, analyses of the dynamics of dyads and groups using time spent writing as a measure of effort demonstrated that boys withdrew more than girls in dyads, whereas girls withdrew more than boys in groups. Furthermore, in groups, girls were more likely than boys to focus on one individual. Causal explanations for sex differences in preferences for differing social structures are proposed. 相似文献
176.
One experiment is described that examined the possible involvement of working memory in the Virtual Errands Test (McGeorge et al. (2001). Using virtual environments in the assessment of executive dysfunction. Presence, 10, 375-383), which requires participants to complete errands within a virtual environment, presented on a computer screen. Time was limited, therefore participants had to swap between tasks (multi-task) efficiently to complete the errands. Forty-two undergraduates participated, all attempting the test twice. On one of these occasions they were asked to perform a concurrent task throughout (order of single and dual-task conditions was counterbalanced). The type of secondary task was manipulated between groups. Twenty-one participants were asked to randomly generate months of the year aloud in the dual-task condition, while another 21 were asked to suppress articulation by repeating the word "December". An overall dual-task effect on the Virtual Errands Test was observed, although this was qualified by an interaction with the order of single and dual-task conditions. Analysis of the secondary task data showed a drop in performance (relative to baseline) under dual-task conditions, and that drop was greater for the random generation group than the articulatory suppression group. These data are interpreted as suggesting that the central executive and phonological loop components of working memory are implicated in this test of multi-tasking. 相似文献
177.
How do we decide whom our friends are? Defining levels of friendship in Poland and the United States
Participants were 57 U.S. college students and 56 Polish university students and copper mine workers who judged the intimacy of 9 hypothetical relationships and also rated the intensity of their relationships with a best friend, a friend, and an acquaintance on the Friendship Intensity Measurement Scale (FIMS; T. S. Arunkumar & B. Dharmangadan, 2001). The present results confirmed that people perceive (a) relationships with best friends as more intense and intimate than other friendships and (b) other friendships as more intense and intimate than acquaintanceships. The results also indicated that Americans perceive all of their relationships, ranging from mere acquaintanceships to intimate friendships, as more intense and intimate than do Poles. It was somewhat surprising that there were no sex differences in either country in the perception of relationships. The authors discussed the research in the context of the difficulty of defining what friendship is and how an individual's cultural background might interact with person variables such as age and sex. 相似文献
178.
Bounding a scientific discipline is a way of regulating its cognitive direction as well as its relations to neighboring disciplines and extra-academic authorities. In this process of identity making, disciplinary history often is a crucial element. In this article, focusing on the historiography of Swedish sociology and the reception of Gustaf Steffen, Sweden's first professional sociologist, it is argued that Steffen's marginalized role in the traditional accounts should be understood not only with reference to his supposed theoretical shortcomings, but also in the historical context of the early postwar reestablishment of sociology as an academic discipline and its prevalent need for a new disciplinary identity, strategically adjusted to the contemporary institutional and political settings. 相似文献
179.
Norman JF Crabtree CE Herrmann M Thompson SR Shular CF Clayton AM 《Perception & psychophysics》2006,68(1):94-101
In two experiments, we investigated the ability of younger and older observers to perceive and discriminate 3-D shape from static and dynamic patterns of binocular disparity. In both experiments, the younger observers' discrimination accuracies were 20% higher than those of the older observers. Despite this quantitative difference, in all other respects the older observers performed similarly to the younger observers. Both age groups were similarly affected by changes in the magnitude of binocular disparity, by reductions in binocular correspondence, and by increases in the speed of stereoscopic motion. In addition, observers in both age groups exhibited an advantage in performance for dynamic stereograms when the patterns of binocular disparity contained significant amounts of correspondence "noise." The process of aging does affect stereopsis, but the effects are quantitative rather than qualitative. 相似文献
180.
This study investigated whether measuring the phenomenology of eyewitness identification decisions aids evaluation of their accuracy. Witnesses (N = 502) viewed a simulated crime and attempted to identify two targets from lineups. A divided attention manipulation during encoding reduced the rate of remember (R) correct identifications, but not the rates of R foil identifications or know (K) judgments in the absence of recollection (i.e., K/[1 − R]). Both RK judgments and recollection ratings (a novel measure of graded recollection) distinguished correct from incorrect positive identifications. However, only recollection ratings improved accuracy evaluation after identification confidence was taken into account. These results provide evidence that RK judgments for identification decisions function in a similar way as for recognition decisions; are consistent with the notion of graded recollection; and indicate that measures of phenomenology can enhance the evaluation of identification accuracy. 相似文献