全文获取类型
收费全文 | 2640篇 |
免费 | 495篇 |
国内免费 | 212篇 |
专业分类
3347篇 |
出版年
2024年 | 7篇 |
2023年 | 52篇 |
2022年 | 60篇 |
2021年 | 76篇 |
2020年 | 169篇 |
2019年 | 181篇 |
2018年 | 174篇 |
2017年 | 186篇 |
2016年 | 167篇 |
2015年 | 145篇 |
2014年 | 143篇 |
2013年 | 627篇 |
2012年 | 88篇 |
2011年 | 138篇 |
2010年 | 79篇 |
2009年 | 101篇 |
2008年 | 101篇 |
2007年 | 107篇 |
2006年 | 76篇 |
2005年 | 74篇 |
2004年 | 66篇 |
2003年 | 50篇 |
2002年 | 41篇 |
2001年 | 34篇 |
2000年 | 37篇 |
1999年 | 20篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 15篇 |
1995年 | 19篇 |
1994年 | 15篇 |
1993年 | 20篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1978年 | 16篇 |
1977年 | 29篇 |
1976年 | 17篇 |
1975年 | 12篇 |
排序方式: 共有3347条查询结果,搜索用时 15 毫秒
201.
202.
Jason Bantjes Stephan Rabie Ellen Almirol Sarah Gordon Jackie Stewart Cameron Goldbeck Robert Weiss Mark Tomlinson Mary Jane Rotheram-Borus 《Aggressive behavior》2020,46(1):5-15
Despite empirical support for “Self-control theory” in criminology, there is controversy about how self-control should be operationalized. Working within the framework of “self-control theory,” we investigated if violence and criminal behaviors are associated with nine distinct dimensions of cognitive control in a community sample of young men (n = 654) living in peri-urban townships in South Africa. Cognitive control was assessed using the Behavior Rating Inventory of Executive Function. Multivariate statistical analysis was used, to identify associations between violence and criminality, and deaggregated measures of nine distinct components of cognitive control. Fifteen percent of the sample reported recent violence, 27% had been in physical fights with family/friends in the preceding 6 months, 10% reported being arrested, 4% reported forced sexual contact, and 26% reported intimate partner violence (IPV). Controlling for substance use and sociodemographic variables, contact with the criminal justice system and violence were associated with deficits in all domains of cognitive control. Forced sexual contact was associated with behavioral dysregulation. IPV was associated with behavior dysregulation and executive control dysfunction. Future studies might utilize deaggregated measures of self-control to provide further insight into links between particular components of cognitive control and various forms of offending and violence. 相似文献
203.
204.
205.
Exchange‐based communication training may not consistently facilitate communication in the absence of the requested item 下载免费PDF全文
The role of stimulus presence on spontaneous communication was assessed with 3 participants in a nonconcurrent multiple baseline with embedded reversals design. Participants were taught to request 2 highly preferred items. Once mastery criterion was met, test sessions were conducted with stimuli either visible or absent from the room, and request rate was measured. For 2 participants, training produced requests in both the presence and absence of the stimulus. For one participant, however, the presence of the stimulus was necessary to evoke the response. Results suggest that teaching individuals to request items when they are present may not consistently lead to requests when those items are absent. 相似文献
206.
207.
208.
On rough terrain, excessive wheel slippage is easily generated by changes of surface conditions such as soil types and geometries. It induces considerable loss of wheel traction and battery energy. To prevent this, wheeled robots should consistently recognize the current situation generated between wheel and surface. And also wheeled robots are required to optimally control wheel motion in limited wheel traction and battery capacity. Therefore, this paper proposes a novel wheel control algorithm based on slip optimization of traction and energy, which is adaptive to change of surface condition. Proposed wheel control algorithm is called Traction-Energy Balancing Adaptive Control (TEB) in this paper and TEB assigns optimized rotation speed to each wheel by observing wheel slip ratio which is a key parameter of TEB. As functions of TEB, TEB is largely divided into three main parts; (1) slip optimizer (2) slip controller (3) SC-compensator. In the slip optimizer, two optimal slip models were derived as a function of slip ratios regarding maximum traction and tractive efficiency using experimental data about wheel-terrain interaction in three types of soil (grass, gravel and sand). And the optimal slip models were employed in order to determine a desired slip value of wheel with observation of a change in actual robot velocity as control input in the slip controller. For optimal slip control, the proposed slip controller is based on conventional PID controller with compensating disturbance in the controller (SC-compensator) which occurs by change of surface shapes. In the SC-compensator, radial function networks (RBFN) was applied in the slip controller and RBFN was of help to readjust previously set PID gains depending on occurred slip error. Finally, TEB was experimentally verified by controlling a real robot having four wheels on various terrain types. 相似文献
209.
210.
Cameron C. Brown Patricia Barros-Gomes Erika N. Smith-Marek Bryan Cafferky Sandra M. Stith 《Journal of couple & relationship therapy》2018,17(2):114-127
Despite previous research suggesting a link between intimate partner violence (IPV) and depression within romantic relationships, few studies have examined the role of depression in couples experiencing violence. Using dyadic data of 129 heterosexual couples seeking couples therapy for high conflict including physical IPV, depressive symptoms were evaluated as a moderator in the association between psychological and physical IPV. Results indicated that moderate and high reports of women's depressive symptoms provided a context, while men's psychological abuse toward them moved from low to high, for women to be more physically abusive toward their partners. Further, low reports of women's depressive symptoms provided a context, while men's psychological abuse toward them moved from low to high, for women to be less physically abusive toward their partners. Better understanding the role of depression and how it may offer a context for physical violence assists helping professionals in holistically addressing violence within romantic relationships. 相似文献