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   2692篇
  免费   137篇
  国内免费   2篇
  2023年   30篇
  2022年   16篇
  2021年   57篇
  2020年   68篇
  2019年   81篇
  2018年   90篇
  2017年   100篇
  2016年   102篇
  2015年   63篇
  2014年   71篇
  2013年   298篇
  2012年   109篇
  2011年   123篇
  2010年   74篇
  2009年   67篇
  2008年   98篇
  2007年   98篇
  2006年   92篇
  2005年   88篇
  2004年   65篇
  2003年   80篇
  2002年   66篇
  2001年   39篇
  2000年   59篇
  1999年   45篇
  1998年   35篇
  1997年   28篇
  1996年   35篇
  1995年   32篇
  1994年   21篇
  1993年   19篇
  1992年   34篇
  1991年   21篇
  1990年   22篇
  1989年   26篇
  1988年   22篇
  1987年   24篇
  1986年   20篇
  1985年   21篇
  1984年   24篇
  1982年   19篇
  1981年   24篇
  1980年   20篇
  1978年   30篇
  1977年   24篇
  1976年   25篇
  1975年   24篇
  1974年   25篇
  1973年   20篇
  1966年   18篇
排序方式: 共有2831条查询结果,搜索用时 15 毫秒
101.
102.
To ascertain how useful the Beck Scale for Suicide Ideation (BSI; Beck & Steer, Manual for Beck Scale for Suicide Ideation (1991)) would be for assessing the severity of suicidal ideation in patients who were diagnosed with schizophrenia, schizoaffective, or bipolar disorders, 142 inpatients were asked to complete the BSI. Eight (6%) patients refused, and four patients (3%) were unable to complete the BSI because they were unable to concentrate. Of the 130 patients who completed the BSI, 53 (41%) had schizoaffective, 37 (28%) had paranoid schizophrenia, 30 (23%) had manic bipolar, and 10 (8%) had depressed bipolar disorders. The coefficient alpha for the BSI was .96, and its one-week test-retest reliability for a subsample of 15 inpatients was 0.88, p < 0.001. The BSI total scores were positively correlated with having ever attempted suicide, r = 0.46, p < 0.001. According to the BSI, 36 (28%) patients were classified as current suicide ideators. The results were discussed as supporting the use of the BSI with inpatients who are diagnosed with schizophrenia, schizoaffective, or bipolar disorders.  相似文献   
103.
This study describes a method of modeling human trunk and whole body backward bending and suggests a possible neural control strategy. The hypothesis was that the control system can be modeled as a linear feedback system, in which the torque acting at a given joint is a function of the state variables (angular positions and angular velocities). The linear system enabled representation of the feedback system by a gain matrix. The matrix was computed from the kinematics recorded by a movement analysis system and from the joint torques calculated by inverse dynamics. To validate the control model, a comparison was made between the angular kinematics yielded by the model and the experimental data. Moreover, for all subjects, the same relationships between feedback coefficients were found although gain values were different. The study showed that the feedback system is an appropriate model of the strategy from performing an accurate controlled trunk or whole body backward bending in the sagittal plane.  相似文献   
104.
Logvinenko AD 《Perception》2002,31(2):201-207
Many researchers believe the human visual system classifies luminance edges into those produced by reflectance edges or those produced by illumination edges, yet this classification process is not completely understood. One suggestion is that heuristics are used for edge classification. For example. specific contrast relationships at the luminance edge ('codirectional contrast invariance' and 'transversal luminance-ratio preserving') may distinguish an illumination edge from a reflectance edge on the one hand, and from a translucent edge on the other. Distinct from luminance junctions, these features are global characteristics of the luminance pattern that make distinguishing between different types of edge easier with more highly articulated scenes. I demonstrate that apparent translucency, nonreversing X-junctions, and single-reversing X-junctions are insufficient on their own to produce the lightness illusion of Adelson's well-known tile pattern. While tolerating violations of the codirectional contrast invariance and transversal-luminance-ratio presersving without reversing the sign of contrast, the visual system is quite sensitive to such contrast reversal at the luminance edge. I account for this by suggesting that humans process lightness in terms of an ordinal, rather than interval, (or ratio) scale.  相似文献   
105.
The influence of a genetic risk factor, apolipoprotein E (apoE) epsilon4 variant, was assessed in older adults aged 70 to 94 on 3 occasions over 7 years. The results of latent growth curve analyses are reported for individuals genotyped for apoE at the 2nd measurement occasion (n = 601) and for a subsample of individuals without probable or definite dementia during the 1st or 2nd occasion (n = 434). ApoE-epsilon4 status was a significant predictor of level and change in memory performance and change in speed performance in the full sample, and of initial level and change in memory performance in the nondemented subsample. These results support previous findings that apoE-epsilon4 is associated with accelerated memory deterioration in individuals without clinical dementia.  相似文献   
106.
The traditional approach to studying behavior explanations involves treating them as either person causes or situation causes and assessing them by using rating scales. An analysis of people's free-response behavior explanations reveals, however, that the conceptual distinctions people use in their explanations are more complex and sophisticated than the person-situation dichotomy suggests. The authors, therefore, introduce a model of the conceptual structure of folk behavior explanations (the network of concepts and assumptions on which explanations are based) and test it in 4 studies. The modes and features of behavior explanations within this conceptual structure also have specific social functions. In 2 additional studies, the authors demonstrate that people alter distinct features of their explanations when pursuing particular impression-management goals and that listeners make inferences about explainers' goals on the basis of these features.  相似文献   
107.
Could monaural loudness adaptation be a simple artifact of psychophysical contrast? From adaptation data based on the Ipsilateral Comparison Paradigm (ICP), A. J. Dange, J. S. Warm, E. M. Weiler, and W. N. Dember (1993) concluded that loudness adaptation was not an artifact of psychophysical contrast, but their conclusion was dependent on results from one intensity. This study, involving multiple intensities, re-examined the issue of contrast versus adaptation and generally supported the conclusions of Dange et al. The results also showed an unexpected asymmetry of adaptation based on the direction of the referent modulation used with the ICP technique. Some implications are discussed.  相似文献   
108.
A fascinating criticism of abortion occasioned by prenatal diagnosis of potentially disabling traits is that the complex test-and-abortion sends a morally disparaging message to people living with disabilities. I have argued that available versions of this "expressivist" argument are inadequate on two grounds. The most fundamental is that, considered as a practice, abortions prompted by prenatal testing are not semantically well-behaved enough to send any particular message; they do not function as signs in a rule-governed symbol system. Further, even granting, for the sake of argument, the expressive power of testing and aborting, it would not be possible, contra the argument's proponents, to distinguish between abortions undertaken because of beliefs about the disabling conditions the fetus might face as a child and abortions undertaken for many other possible reasons -- e.g., because of the poverty the fetus would face or the increase in family size that the birth of a new child would occasion. Here, I respond to criticisms of those arguments, and propose and defend another: the expressivist argument cannot, in general, distinguish successfully between abortion and therapy as modalities for responding to disabilities.  相似文献   
109.
Cued recall success varies with what people know and with what they do during an episode. This paper focuses on prior knowledge and disentangles the relative effects of 10 features of words and their relationships on cued recall. Results are reported for correlational and multiple regression analyses of data obtained from free association norms and from 29 experiments. The 10 features were only weakly correlated with each other in the norms and, with notable exceptions, in the experiments. The regression analysis indicated that forward cue-to-target strength explained the most variance, followed by backward target-to-cue strength. Target connectivity and set size explained the next most variance, along with mediated cue-to-target strength. Finally, frequency, concreteness, shared associate strength, and cue set size also contributed significantly to recall. Taken together, indices of prior word knowledge explain 49% of the recall variance. Theoretically driven equations that use free association to predict cued recall were also evaluated. Each equation was designed to condense multiple indices of word interconnectivity into a single predictor.  相似文献   
110.
Three experiments addressed factors that might influence whether or not young children take into account function, as opposed to overall appearance or shape, when they extend the names of novel artifacts. Experiment 1 showed that 4-year-olds more often extend a name on the basis of a demonstrated function when that function provides a plausible causal account of perceptible object structure. Experiment 2 showed that they more often extend a name by function when they respond slowly, and hence thoughtfully. Experiment 3 demonstrated that they are more likely to take function into account when they extend names than when they judge similarities. Comparisons of lexical and non-lexical conditions in younger children failed to show any differences. Overall, the findings suggest that by 4 years of age, children may learn names as labels for novel artifact kinds rather than perceptual classes, and that the processes by which they categorize may be mindful and reflective, as in adults.  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