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   3449篇
  免费   534篇
  国内免费   162篇
  4145篇
  2024年   54篇
  2023年   58篇
  2022年   69篇
  2021年   98篇
  2020年   137篇
  2019年   124篇
  2018年   140篇
  2017年   143篇
  2016年   137篇
  2015年   105篇
  2014年   135篇
  2013年   288篇
  2012年   216篇
  2011年   260篇
  2010年   181篇
  2009年   202篇
  2008年   231篇
  2007年   268篇
  2006年   261篇
  2005年   204篇
  2004年   154篇
  2003年   106篇
  2002年   81篇
  2001年   53篇
  2000年   49篇
  1999年   51篇
  1998年   41篇
  1997年   35篇
  1996年   31篇
  1995年   27篇
  1994年   18篇
  1993年   19篇
  1992年   15篇
  1991年   18篇
  1990年   13篇
  1989年   11篇
  1988年   10篇
  1987年   9篇
  1986年   10篇
  1985年   12篇
  1984年   14篇
  1983年   7篇
  1982年   11篇
  1981年   7篇
  1980年   6篇
  1979年   9篇
  1977年   2篇
  1975年   3篇
  1974年   3篇
  1973年   3篇
排序方式: 共有4145条查询结果,搜索用时 0 毫秒
211.
Abstract

Phase stability of the intermetallic compound Al3Nb is investigated as a function of nickel additions by band structure calculations based on an extended Hueckel tight-binding method. With this method, the electronic structure and total energies of the Al6-n -Ni n Nb2 compounds (where n is an integer from 0 to 6) are calculated for both D022 and L12 structures under the assumption that nickel substitutes for aluminium. The electronic total energies obtained from integration of the energy states of all electrons considered have shown that the D022 structure is stable in the binary Al3Nb compound as compared with the L12 structure; conversely, the L12 structure is stable for compounds with n values greater than 1. These calculations are in good agreement with X-ray diffraction results reported by Schubert and co-workers. Differences in the electronic total energy per atom between D022 and L12 are - 0·79 eV and 0·56 eV for n equal to 0 and 2, respectively.  相似文献   
212.
In this cross-cultural study, 115 Hong Kong Chinese and 117 Brazilian college students described a childhood peak-experience (occurring before the age of 14) and provided a self-rating on its enduring impact. Among various categories of peak-experiences, both Hong Kong Chinese and Brazilians reported interpersonal joy most frequently; the second most frequently reported category was external achievement for the Hong Kong sample and developmental landmark for the Brazilian sample. Compared with Brazilians’ narratives, those of Hong Kong Chinese were more social-focused, involving greater number of other people, but less specific. These characteristics of autobiographical memory, i.e., memory focus (self vs. social), memory specificity (specific vs. general), and the number of other people involved, significantly mediated the relation between culture and interpersonal joy. The present findings have extended research on peak-experiences to cross-cultural contexts and incorporated measures of autobiographical memory to unpack cultural variations in these two collectivist societies.  相似文献   
213.
成人期人际性问题解决的策略取向研究   总被引:7,自引:0,他引:7  
采用开放式问卷,考察252名25至75岁的成人解决人际性问题的策略取向。结果表明:总体上中国成人偏重于二级控制取向;成人前期个体较其他年龄段成人表现出更多的一级控制取向;情境因素对成人的策略取向有较大影响,并且这种影响对不同年龄段成人所产生的效应存在明显差异。  相似文献   
214.

Representing spatial information is one of our most foundational abilities. Yet in the present work we find that even the simplest possible spatial tasks reveal surprising, systematic misrepresentations of space—such as biases wherein objects are perceived and remembered as being nearer to the centers of their surrounding quadrants. We employed both a placement task (in which observers see two differently sized shapes, one of which has a dot in it, and then must place a second dot in the other shape so that their relative locations are equated) and a matching task (in which observers see two dots, each inside a separate shape, and must simply report whether their relative locations are matched). Some of the resulting biases were shape specific. For example, when dots appeared in a triangle during the placement task, the dots placed by observers were biased away from certain parts of the symmetry axes. But other systematic biases were not shape specific, and seemed instead to reflect differences in the grain of resolution for different regions of space. For example, with both a circle and even a shapeless configuration (with only a central landmark) in the matching task, observers were better at discriminating angular differences (when a dot changed positions around the circle, as opposed to inward/outward changes) in cardinal versus oblique sectors. These data reveal a powerful angular spatial bias, and highlight how the resolution of spatial representation differs for different regions and dimensions of space itself.

  相似文献   
215.
The purpose of this experiment was to examine the combined effects of self-control and frequency of model presentation on learning a complex motor skill, i.e., ballet passé relevé. Before practice started self-control participants were asked to choose two viewings or six viewings (before practice and then every five trials) and the externally controlled groups were yoked to their self-control counterparts. All participants completed 15 acquisition trials followed by 5 trials for the immediate and 5 trials for the delayed retention tests 48 hours later. Dependent variables included cognitive representation scores, physical reproduction rankings, and balance time. Statistical analyses indicated that under limited physical practice conditions self-control and higher frequency of model presentation facilitated the development of cognitive representation and did not produce further benefits in movement reproductions and balance time. The results were discussed with respect to the social cognitive theory.  相似文献   
216.
本文对“解构”思潮颠覆“形而上者”所可能达到的限度作了审慎辨析,并就此探讨了形上之维更生的价值依据及新形态的形而上学得以构建的语言契机。  相似文献   
217.
在古希腊理性精神与基督教信仰文化交汇的大背景下,奥古斯丁扬弃柏拉图和亚里士多德等思想家的理性自由观,提出了以基督教信仰为基础的信仰自由观。这种自由观展示了信仰、自由意志和理性三者之间富有张力的依存关系,实现了西方自由观的转向,对后来的西方哲学与文化发生了深远影响。这种自由观在德国古典哲学尤其是黑格尔的哲学中得到复兴,但由于从根本上并没有克服自由与决定论之间的困境,现实的人的自由、理性与信仰在黑格尔哲学中都被消解了。即便如此,在当代一些重要的思想家那里,奥古斯丁确立的思维范式依然具有实质性影响。  相似文献   
218.
历史上对伏牛山地区的佛教记载较散,资料较详的是在明代。当时来山修行的僧人很多,但是到现在为止还没有人对伏牛山的佛教进行过研究,笔者根据掌握的禅宗史料提出这时伏牛山佛教已经有了明显的禅宗派系特征,在这里传教修行的僧人,主要是元代禅宗断桥伦一支的浙江天目山高峰原妙及其弟子中峰明本一系,其中受四川禅宗无际明悟禅师一派的影响很大,早期来山的僧人大多数都是无际明悟的弟子与后人,可以说成立了无际伏牛山禅派一系。  相似文献   
219.
探讨一致的先前知识对类别学习的影响,包括2个实验。被试是112名大学生,分别探讨不同实验任务和不同项目呈现时间引发的机械特征在类别学习中的重要程度和加工程度不同的情况下先前知识对类别学习的影响。结果表明:(1)在实验任务为项目类别归属判断任务时,机械特征重要程度低,主题特征与机械特征在学习上存在竞争关系;在实验任务为项目类别归属及记忆任务时,机械特征重要程度高,主题特征与机械特征在学习上存在促进关系。(2)在限制步速呈现项目时,机械特征加工程度低,主题特征与机械特征在学习上存在竞争关系;而在自定步速呈现项目时,机械特征加工程度高,主题特征与机械特征在学习上不存在竞争关系。  相似文献   
220.
时间性前瞻记忆是指形成和保持一个意向,在一段时间后的某个特定的时间(目标时间)执行.文章通过对时间性前瞻记忆的研究取向、方法和现有理论模型的回顾,总结出该领域中的三个争论焦点.  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