首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   736篇
  免费   250篇
  国内免费   45篇
  1031篇
  2024年   2篇
  2023年   13篇
  2022年   8篇
  2021年   32篇
  2020年   16篇
  2019年   72篇
  2018年   90篇
  2017年   103篇
  2016年   69篇
  2015年   56篇
  2014年   31篇
  2013年   74篇
  2012年   26篇
  2011年   34篇
  2010年   23篇
  2009年   28篇
  2008年   22篇
  2007年   18篇
  2006年   17篇
  2005年   14篇
  2004年   6篇
  2003年   7篇
  2002年   6篇
  2001年   8篇
  2000年   3篇
  1999年   6篇
  1998年   5篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   6篇
  1988年   1篇
  1985年   25篇
  1984年   21篇
  1983年   25篇
  1982年   28篇
  1981年   19篇
  1980年   21篇
  1979年   28篇
  1978年   10篇
  1977年   15篇
  1976年   16篇
  1975年   9篇
  1974年   5篇
  1973年   2篇
排序方式: 共有1031条查询结果,搜索用时 0 毫秒
971.
为了探讨高中生亲子沟通质量对情绪性刺激注意偏向的影响,实验一采用亲子沟通量表,筛选出亲子沟通高分组和低分组,两组被试参加点探测任务,要求被试迅速判断情绪性图片出现后呈现的圆点的位置。实验为2(组别:高亲子沟通组、低亲子沟通组)×2(情绪类型:负性和正性)×2(探测点位置一致性:一致、不一致)的混合实验设计。结果发现,负性和正性刺激的不一致条件反应时均显著短于一致条件的反应时。实验二采用事件相关电位(ERP)记录了情绪性图片诱发的信号反应。结果发现,亲子沟通高分组对负性刺激所诱发的注意指向和集中(P2成分)及选择和巩固(P3成分)显著高于低分组。以上结果表明,亲子沟通较好,在注意早期定向和选择中会对负性情绪刺激产生注意偏向。亲子沟通较差,则对情绪性的刺激没有明显的偏向性,类似于“漠不关心”的状态。  相似文献   
972.
Although family systems theory posits reciprocal causality between subsystems of the family, such as intimate partner violence exacerbating harsh parenting and vice versa, longitudinal studies with cross‐lagged models have been used infrequently to test these principles. As guided by the spillover model, this study examined bidirectional associations between couple dysfunction, parent–child aggression risk, and child functioning across the transition to parenthood to determine whether and how disruptions in one subsystem relate to problems in other family subsystems. Participants were 201 first‐time mothers and 151 fathers from a diverse community sample, evaluated during pregnancy, and reassessed two more times through their child's first 18 months of life. Individual and dyadic path model results indicate bidirectional spillover effects between parent–child aggression risk and child functioning for both mothers and fathers, and spillover from parent–child aggression risk to couple dysfunction for mothers but not fathers. However, limited spillover effects were identified between couple functioning and child adjustment, in contrast to previous work. Findings suggest that spillover can happen reciprocally and early in the family, supporting transactional models of behavior and highlighting the need for early family level intervention.  相似文献   
973.
The present study examined the locus where inhibition of non-target languages is exerted during trilingual word production by analyzing the cue-locked and stimulus-locked ERPs respectively in the n-2 language repetition paradigm. During the experiment, Uighur–Chinese–English trilinguals overtly named Arabic digits in one of their three languages according to a visually presented cue while their behavioral and electrophysiological responses were recorded. The behavioral data revealed insignificant n-2 repetition costs. Cue-locked ERPs revealed also only tiny or marginally significant n-2 repetition effects over some midline electrodes. The stimulus-locked ERP data showed a more negative ERP component elicited by the n-2 repetition trials than the n-2 non-repetition trials around 250 ms after stimulus onset, but no significant difference in this ERP effect between different languages was found. The results indicate that inhibition of non-target languages occurs at the lemma selection phase rather than the language task schemas phase during trilingual language production.  相似文献   
974.
975.
The purpose of this study was to examine the associations between using unhealthy substances and the digit ratio (2nd to 4th digit length ratio, 2D:4D) which is supposed to indicate the prenatal testosterone level. The subjects were 455 students, 225 women and 230 men. Participants declared their frequency of smoking and alcohol drinking. There was no significant difference in digit ratios between subjects regularly using both nicotine and alcohol and those who took none of them. When analyzing the two substances separately, there was no relationship between 2D:4D and alcohol drinking, whereas left hand 2D:4D was positively related to smoking only for women (nonsignificant trend was observed for right hand). Contrary to the previous study, our results indicate that there is no relationship between 2D:4D and alcohol drinking. There is, however, a subtle influence of prenatal testosterone levels for cigarette smoking habits in the case of women.  相似文献   
976.
Molecular mechanics simulations were performed to probe the incipient plastic deformation in carbon nanotubes (CNTs), which involves nucleation of Stone–Wales (SW) defects and spiral glide of 5/7 dislocation dipoles that lead to quantized necking through a stepwise reduction in tube diameter. Quantification of the strain-dependent energetics of dislocation glide reveals that such dislocation motions are energetically favoured at high tensile strain. Pre-existing dislocations critically affect subsequent nucleation and separation of SW defects, as manifested by the competing deformation modes of symmetric versus asymmetric necking. The results provide a quantitative basis for the dislocation dynamics simulations of superplastically deformed CNTs.  相似文献   
977.
A very simple derivation is given for the dependence of localisation length on boundary velocity and various model parameters, in the continuum theory of 2D foam shear localisation. It is pointed out that the existence of distinct yield and limit stresses can complicate this theory for low boundary velocities, by introducing another mechanism for localisation, which does not depend on wall drag.  相似文献   
978.

Defect formation in Nd2Fe14B grains, caused by a low-pressure-pack-sublimation Zn coating process, has been investigated. The results indicate that, in the Zn-affected region, low-angle boundaries decorated with precipitates form within the Nd2Fe14B grains. Zn, which is almost insoluble in Nd2Fe14  相似文献   
979.

By eliminating the effect of the magnetic moment arising from the magnetic crystalline anisotropy, the effect of the thermoelectric magnetic force on the array of dendrites during directional solidification of Al–35?wt%Cu and Al-40?wt%Cu alloys in a high magnetic field has been investigated experimentally. The results indicate that the dendrite array is essentially destroyed, a result that could have general significance for understanding the processes involved in the solidification of alloys in a magnetic field.  相似文献   
980.

Fundamental changes in sciences offer new perspectives for the management of complexity. Increased complexity in society, economics, and technology requires a new and suitable organization and management. What are the consequences and results for project management? That is the theme of this article. First of all it will given a short introduction to project management, which will be later called “traditional project management” or “project management 1st order (PM-1).” Then, the challenges by the fundamental changes in sciences and the increased complexity in society, economics, and technology will be discussed. It will state that traditional project management cannot solve these challenges. The widespread working-themes and results of the research program “Beyond Frontiers of Traditional Project Management” as an answer to these challenges will be presented at a glance. Subsequently, it will discuss some selected results of the research program:
  • The principle-definition and foundation of “Evolution of 1st and 2nd Order.”

  • The Evolution of 1st Order and the impact on Project Management methods and processes.

  • Evolution of 2nd Order and the Grand Evolutionary Systems Theory (GEST) of E. Laszlo as also the impact on Project Management methods and processes.

  • Management of crisis: turn a change to advantage or risk-assurance?

Thereafter, the concept of “Project Management Second Order (PM-2)” is presented as a highlighted result of the research program, as a new paradigm in project management, and as an answer to the challenges, described earlier will be explained in detail. Finally, a real example of transfer evolutionary and self-organizational management principles in a real project life will be demonstrated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号