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   633篇
  免费   57篇
  国内免费   140篇
  2024年   1篇
  2023年   15篇
  2022年   15篇
  2021年   32篇
  2020年   34篇
  2019年   11篇
  2018年   22篇
  2017年   27篇
  2016年   25篇
  2015年   18篇
  2014年   29篇
  2013年   72篇
  2012年   24篇
  2011年   44篇
  2010年   35篇
  2009年   50篇
  2008年   36篇
  2007年   65篇
  2006年   51篇
  2005年   48篇
  2004年   27篇
  2003年   24篇
  2002年   12篇
  2001年   9篇
  2000年   10篇
  1999年   10篇
  1998年   8篇
  1997年   8篇
  1996年   5篇
  1995年   6篇
  1994年   6篇
  1993年   5篇
  1992年   4篇
  1991年   4篇
  1990年   2篇
  1989年   4篇
  1988年   1篇
  1987年   2篇
  1986年   5篇
  1985年   5篇
  1984年   7篇
  1982年   1篇
  1981年   4篇
  1980年   3篇
  1979年   4篇
排序方式: 共有830条查询结果,搜索用时 15 毫秒
741.
As China opens its door to the world, suicide research is making rapid progress using methods and instruments developed in the West. This is a feasibility study of the psychological autopsy methodology applied in China, with its emphasis on the social and cultural environments. With samples of 66 completed suicides and 66 community normal living controls, the authors found that it is feasible to interview at least two informants for each suicide case and each control, between 2 and 6 months after the suicide. With the Chinese-cultivated contacting method of recruiting cases, the refusal rate is nearly zero. The Western-developed methodology per se proved to be valid in the Chinese culture. Ethical considerations in the context of Chinese culture are as important as in the West. Psychological autopsy technique is shown to be an equally applicable method for the study of completed suicides in Chinese culture as it is in the West. Future epidemiological research on Chinese suicide should use the psychological autopsy method to collect data from larger samples in order to increase our understanding of the risk factors for Chinese suicides.  相似文献   
742.

A new decagonal quasicrystal (the D phase) with a period of about 1.6 nm was found to form in conventionally solidified and heat-treated Al75Ni15Ru10 alloys. The electron diffraction patterns of the Al-Ni-Ru D phase exhibit a large number of quite sharp diffraction spots located at precise decagonal symmetry positions, indicating a highly ordered decagonal quasicrystal with a long-range quasiperiodic correlation. The D phase is formed with a composition close to Al74Ni15Ru11, as determined by energy-dispersive X-ray analysis. By means of high-resolution electron microscopy, the structural features of the Al-Ni-Ru D phase, which are obviously different from that of the Al-Pd D phase (a typical decagonal quasicrystal with 1.6 nm periodicity reported previously), have been revealed.  相似文献   
743.
The mechanical properties of periodic composites containing identical spherical particles are investigated using the principles of micromechanics and homogenization procedures. The averaged strain and stress fields are derived in terms of an eight-particle interaction. The effective elasticity with the cubic symmetry tensor is explicitly obtained. If the interaction term is dropped, then one recovers the conventional Mori–Tanaka model. With further approximations, the dilute model and the self-consistent model can also be obtained within the proposed framework. It is observed that the particle interactions make no contribution to the effective bulk modulus, a result that is consistent with other models and experiments for composites with cubic lattices.  相似文献   
744.
The valence band structures of the NiAl–Mo alloy was investigated by photoelectron spectroscopy. The valence band spectra of the NiAl–Mo alloy was shifted away from the Fermi level so that the Ni-d-band centroid moved to a higher energy by 0.22 eV as Mo was added. A possible explanation lied in the overlap of Ni-d bands in the energy with Mo-d and Al-p bands. The participation of Mo-d bands was correlated with the site preference of Mo in NiAl alloys.  相似文献   
745.

An ordered structure, which was found in a decagonal quasicrystal with 0.4 nm periodicity in a conventionally solidified Al70Ni20Ru10 alloy, has been examined theoretically by the projection of an ordered body-centred (CsCl-type) hypercubic lattice. The ordered structure can be characterized as an ordered arrangement of two kinds of atom columnar cluster with different directions of pentagonal symmetry. Two lattices, which are constructed by connecting the atom clusters in the same directions, can be interpreted as ordered sublattices formed by each of vertex and body-centred positions of the CsCl-type hypercubic lattice. Diffraction patterns calculated from the ordered and disordered body-centred hypercubic lattices replicate well the electron diffraction patterns observed from the Al-Ni-Ru and other decagonal quasicrystals.  相似文献   
746.
747.
The social identity of another person, in addition to the social identity of self, can be an important factor affecting the types of attribution judgments and emotions that individuals indicate for the other person. In April 2007, the perpetrator of the shooting incident on the Virginia Tech University campus was identified as a person who emigrated to the USA from Korea at a young age. The current study compared non‐Korean Americans, Korean Americans, Koreans in the USA, and Koreans in Korea in terms of their attributions and emotions concerning the perpetrator and the shooting incident. Participants were asked to indicate (1) the extent to which they attributed the cause of the incident to either American society or the perpetrator, (2) their emotions (e.g., upset), and (3) the extent to which they categorized the perpetrator as an American, a Korean American, or a Korean. The results indicated that non‐Korean Americans were most likely to attribute the cause of the incident to the perpetrator as opposed to American society. Non‐Korean Americans, Korean Americans, and Koreans in the United States had more negative emotions (e.g., unhappy, sad, and upset) about the incident than Koreans in Korea did. The results also indicated that individuals differed in their attributions and emotions depending on how they categorized the perpetrator. For example, categorizing the perpetrator as being a Korean was positively related to Americans’ tendency to hold the perpetrator responsible, while categorizing the perpetrator as being an American was negatively related to the tendency to hold the perpetrator responsible among Koreans in Korea. The findings may imply that social identity theory, intergroup emotion theory, and cultural orientations (e.g., individualism and collectivism) can provide insights into people's reactions to a tragic incident.  相似文献   
748.
孙崇勇  刘电芝 《心理科学》2013,36(1):195-202
运用双任务实验范式,比较了三种认知负荷主观评价量表的灵敏度与效度。结果发现:在本研究任务条件下,次任务反应时的稳定性、抗干扰性较好,可以作为认知负荷主观评价的标尺;WP量表与PAAS量表的敏感性均较好,其中WP量表的敏感性、诊断性高于后者,TLX量表的敏感性较弱;WP量表与PAAS量表的效度较好,且好于TLX量表。综合各项指标,在中低难度任务下,WP量表是目前认知负荷较为理想的测量工具。  相似文献   
749.
张承芬  孙金玲 《心理科学》2013,36(1):134-138
本研究从工作记忆容量的角度入手,探讨数学焦虑对工作记忆子系统及数学心算成绩的影响,并寻求三者之间关系的理论解释。本研究为3×2×2混合实验设计,即三组被试(高、中、低数学焦虑组)、工作记忆两个子系统(言语工作记忆和视空间工作记忆)和两种数学心算任务难度,并记录数学心算的反应时和正确率作为其成绩指标。结果表明在要求较高工作记忆容量的数学心算任务中,数学焦虑通过言语工作记忆和视空间工作记忆都会对数学心算成绩产生影响,其中视空间工作记忆是数学焦虑与复杂数学心算反应时之间的中介变量。  相似文献   
750.
通过文献检索及对43名高校校长及其直接下属的访谈,经专家讨论,编制了中国高校校长变革型领导行为量表。515份数据的探索性因素分析和461份数据的验证性因素分析结果表明,中国高校校长的变革型领导行为是五因素结构,即德行垂范、关怀激发、愿景激励、领导魅力、团结协作。问卷具有良好的信效度。回归分析结果表明,高校校长的变革型领导行为对教师组织承诺具有正向影响,其中,教师的内部动机与学校的组织氛围对二者的关系具有完全中介作用。  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