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   6808篇
  免费   127篇
  国内免费   2篇
  2023年   31篇
  2022年   22篇
  2021年   39篇
  2020年   68篇
  2019年   73篇
  2018年   208篇
  2017年   185篇
  2016年   287篇
  2015年   167篇
  2014年   108篇
  2013年   329篇
  2012年   388篇
  2011年   381篇
  2010年   99篇
  2009年   94篇
  2008年   127篇
  2007年   146篇
  2006年   120篇
  2005年   1398篇
  2004年   722篇
  2003年   513篇
  2002年   213篇
  2001年   76篇
  2000年   49篇
  1999年   65篇
  1998年   37篇
  1997年   24篇
  1996年   22篇
  1995年   20篇
  1994年   31篇
  1993年   25篇
  1992年   49篇
  1991年   52篇
  1990年   69篇
  1989年   53篇
  1988年   36篇
  1987年   58篇
  1986年   54篇
  1985年   39篇
  1984年   38篇
  1983年   32篇
  1979年   40篇
  1976年   20篇
  1975年   33篇
  1974年   36篇
  1973年   34篇
  1972年   27篇
  1971年   28篇
  1970年   19篇
  1969年   19篇
排序方式: 共有6937条查询结果,搜索用时 15 毫秒
81.
An investigation was made into the extent and time course of anticipatory coarticulation in the speech of two normal and two anterior aphasic, German-speaking subjects. Both labial and velar coarticulation gestures were investigated. Subjects produced sentences containing target words contrasting in postconsonantal vowel rounding (e.g., [geli:ge]/[gely:gel]) and in nasality (e.g., [ti:de]/[ti:ne]). Speech kinematics were monitored by means of electromagnetic articulography. The data revealed that for correct productions, aphasic speakers' coarticulatory patterns were more highly variable than those of control subjects. These differences, however, were found chiefly for spatial displacement characteristics, while the temporal aspects of articulator movement necessary for anticipatory coarticulation appeared largely intact. Articulator mistiming did not appear to explain a small corpus of stop/nasal substitution errors produced by one of the aphasic speakers.  相似文献   
82.
Summary The role of intention in guiding the behavior of goal-directed systems is a problem that continues to challenge behavioral science. While it is generally agreed that intentional systems must be consistent with the laws of physics, there are many obvious differences between inanimate, physical systems and sentient, intentional systems. This suggests that there must be constraints over and above those of physics that govern goal-directed behavior. In this paper it is suggested that generic properties of self-organizing mechanisms may play a central role in the origin and evolution of intentional constraints. The properties of self-organizing systems are first introduced in the context of simple physical systems and then extended to a complex (biological) system. Whereas behavior of an inanimate physical system is lawfully determined by force fields, behavior of an animate biological system is lawfully specified by information fields. Biological systems are distinguished from simple physical systems in terms of their ubiquitous use of information fields as special (biological and psychological, social, etc.) boundary conditions on classical laws. Unlike classical constraints (boundary conditions), informational constraints can vary with time and state of the system. Because of the nonstationarity of the boundary conditions, the dynamic of the system can follow a complex trajectory that is organized by a set of spatially and temporally distributed equilibrium points or regions. It is suggested that this equilibrium set and the laws that govern its transformation define a minimal requirement for an intentional system. One of the benefits of such an approach is that it suggests a realist account for the origin of semantic predicates, thereby providing a basis for the development of a theory of symbolic dynamics. Therefore, the principles of self-organization provide a comprehensive basis for investigating intentional systems by suggesting how it is that intentions arise, and by providing a lawful basis for intentional behavior that reveals how organisms become and remain lawfully informed in the pursuit of their goals.  相似文献   
83.
The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.  相似文献   
84.
85.
Attention/likelihood theory has been used to explain the mirror effect in recognition memory. The theory also predicts that any manipulation that affects the recognition of old items will also affect recognition of the new items—more specifically, that all the underlying distributions will move and that they will move symmetrically on the decision axis. In five experiments, we tested this prediction. The first two experiments used encoding tasks during study to change recognition performance for high- and low-frequency words. The results show symmetrical dispersion of the underlying distributions. The final three experiments used repetition to increase recognition performance. Repetition produced a symmetrical pattern of movement that was different from that produced by encoding task. This pattern is, however, also covered by attention/likelihood theory. A further extension of the theory was used to predict response times.  相似文献   
86.
The ability to compensate for fixation of the jaw by a bite block was investigated in 6 nonfluent aphasics, 6 fluent aphasics, and 10 normal control subjects. Acoustic analyses of the vowels [i u a æ] and fricatives [s s] revealed substantial but incomplete compensation for the perturbation in all three subject groups. Perceptual identification scores and quality ratings by naive and phonetically trained listeners indicated poorer identification of the high vowels [i u] under compensatory conditions relative to normal production. Of particular interest was the fact that all three groups of subjects exhibited similar patterns of results. The findings suggest that any deficit in speech motor programming demonstrated by the nonfluent aphasic patients did not affect compensatory abilities. Results are discussed with respect to normal speech adaptation skills and the nature of articulatory breakdown in nonfluent aphasia.  相似文献   
87.
Mooney  Kim M.  Lorenz  Erica 《Sex roles》1997,36(9-10):639-653
Male and female subjects provided ratings of personal traits, femininity and masculinity, and total caloric consumption for a female or a male target based on the type of diet she or he had allegedly consumed. The gender associated with the foods presented for each dietary profile was manipulated. Results showed that Target Gender and Dietary Profile significantly affected impression ratings and calorie estimates. Both male and female subjects perceived male eaters and those who ate a feminine diet more favorably. Results are discussed in terms of the different underlying expectations held for males and females when food consumption is involved during the impression formation process.  相似文献   
88.
The present investigation reported the development and validation of the Knowing Styles Inventory (KSI), a scale to measure connected and separate knowing [M. F. Belenky, B. M. Clinchy, N. R. Goldberger, and J. M. Tarule (1986), Women's Ways of Knowing: The Development of Self, Voice, and Mind New York, Basic Books]. In Study 1, principal components analyses for samples of females (N = 300) and males (N = 253) yielded two components, Connected and Separate Knowing. Studies 2 and 3 focused on females exclusively. The results indicated adequate test—retest reliability and internal consistency for both components. Additionally, Connected Knowing was positively correlated with empathic concern, perspective-taking, social desirability, and the femininity factor of the Bem Sex Role Inventory (BSRI). Separate Knowing was positively correlated with the masculinity factor of the BSRI and negatively correlated with social desirability. Suggestions for future research were presented.The authors wish to thank Jill Mattuck Tarule for the insight that she offered in the early stages of this project, and they wish to acknowledge the contribution of Nicole Bressler who participated in item development.  相似文献   
89.
This article examines the current role of direct-care staff, and their significance to individuals with disabilities living in the community. The role of staff will be redefined with respect to client normalization within the community. Finally, a framework for training staff is provided.  相似文献   
90.
This paper addresses a problem in reporting scientific research. The problem is how to distinguish between justifiable and unjustifiable data selection. Robert Millikan is notorious for an infamous remark that he used all his data when in fact he had used a selection. On this basis he has been accused of fraud. There is a tension here — historians and his defenders see his selection as understandable and legitimate, while current statements about the Responsible Conduct of Research imply his selection was illegitimate. This paper discusses two main issues that arise in assessing his conduct, whether he was intentionally misleading and whether he actually did mislead the scientific community about some facts of nature. It is argued that he was not intentionally misleading, and that it is unlikely that he misled the scientific community.  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