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   3410篇
  免费   198篇
  国内免费   10篇
  2023年   45篇
  2022年   35篇
  2021年   42篇
  2020年   89篇
  2019年   95篇
  2018年   123篇
  2017年   128篇
  2016年   137篇
  2015年   74篇
  2014年   105篇
  2013年   392篇
  2012年   158篇
  2011年   187篇
  2010年   119篇
  2009年   113篇
  2008年   132篇
  2007年   152篇
  2006年   131篇
  2005年   111篇
  2004年   98篇
  2003年   94篇
  2002年   101篇
  2001年   81篇
  2000年   51篇
  1999年   50篇
  1998年   35篇
  1997年   31篇
  1996年   30篇
  1995年   36篇
  1994年   44篇
  1993年   25篇
  1992年   36篇
  1991年   24篇
  1990年   26篇
  1989年   24篇
  1988年   28篇
  1987年   22篇
  1986年   25篇
  1985年   31篇
  1984年   22篇
  1983年   23篇
  1982年   19篇
  1980年   16篇
  1979年   25篇
  1978年   33篇
  1977年   26篇
  1976年   15篇
  1975年   17篇
  1974年   20篇
  1973年   19篇
排序方式: 共有3618条查询结果,搜索用时 15 毫秒
971.
The neural plasticity necessary for acquisition and retention of eyeblink conditioning has been localized to the cerebellum. However, the sources of sensory input to the cerebellum that are necessary for establishing learning-related plasticity have not been identified completely. The inferior colliculus may be a source of sensory input to the cerebellum through its projection to the medial auditory thalamus. The medial auditory thalamus is necessary for eyeblink conditioning in rats and projects to the lateral pontine nuclei, which then project to the cerebellar nuclei and cortex. The current experiment examined the role of the inferior colliculus in auditory eyeblink conditioning. Rats were given bilateral or unilateral (contralateral to the conditioned eye) lesions of the inferior colliculus prior to 10 d of delay eyeblink conditioning with a tone CS. Rats with bilateral or unilateral lesions showed equivalently impaired acquisition. The extent of damage to the contralateral inferior colliculus correlated with several measures of conditioning. The findings indicate that the contralateral inferior colliculus provides auditory input to the cerebellum that is necessary for eyeblink conditioning.  相似文献   
972.
The essential neural circuitry for delay eyeblink conditioning has been largely identified, whereas much of the neural circuitry for trace conditioning has not been identified. The major difference between delay and trace conditioning is a time gap between the presentation of the conditioned stimulus (CS) and the unconditioned stimulus (US) during trace conditioning. It is this time gap or trace interval which accounts for an additional memory component in trace conditioning. Additional neural structures are also necessary for trace conditioning, including hippocampus and prefrontal cortex. This addition of forebrain structures necessary for trace but not delay conditioning suggests other brain areas become involved when a memory gap is added to the conditioning parameters. A metabolic marker of energy use, radioactively labeled glucose analog, was used to compare differences in glucose analog uptake between delay, trace, and unpaired experimental groups in order to identify new areas of involvement within the cerebellum. Known structures such as the interpositus nucleus and lobule HVI showed increased activation for both delay and trace conditioning compared to unpaired conditioning. However, there was a differential amount of activation between anterior and posterior portions of the interpositus nucleus between delay and trace, respectively. Cerebellar cortical areas including lobules IV and V of anterior lobe, Crus I, Crus II, and paramedian lobule also showed increases in activity for delay conditioning but not for trace conditioning. Delay and trace eyeblink conditioning both resulted in increased metabolic activity within the cerebellum but delay conditioning resulted in more widespread cerebellar cortical activation.  相似文献   
973.
This article proposes 2 new approaches to test a nonzero population correlation (rho): the hypothesis-imposed univariate sampling bootstrap (HI) and the observed-imposed univariate sampling bootstrap (OI). The authors simulated correlated populations with various combinations of normal and skewed variates. With alpha set=.05, N> or =10, and rho< or =0.4, empirical Type I error rates of the parametric r and the conventional bivariate sampling bootstrap reached .168 and .081, respectively, whereas the largest error rates of the HI and the OI were .079 and .062. On the basis of these results, the authors suggest that the OI is preferable in alpha control to parametric approaches if the researcher believes the population is nonnormal and wishes to test for nonzero rhos of moderate size.  相似文献   
974.
As the number of internet users increases, a new game genre using the internet as a networking tool is emerging. Some game genres are regarded as having greater addiction potentials than others. Games and the internet are closely related. We investigated games frequently used by adolescents and classified each of them with the help of game professionals. We also examined internet use patterns to identify relationships between game genre and internet use patterns. 627 middle school and high school students (male 488, female 139) completed questionnaires concerning computer and game use patterns and Korean internet addiction scales. Game genres were divided into eight criteria (simulation, role playing game, web board, community, action, adventure, shooting, and sports). Using Korean internet addiction scales, 627 participants were divided into a normal group (474), a potential risk group (128), and a high-risk group (25). Each group showed significant differences in total internet addiction scores. We classified players into specific game users based upon the game types they most prefer. Role playing game users showed significantly higher internet addiction scores than web board and sports game users. Game and internet addictions are also connected with interpersonal relationship patterns. We suggest that users of some game genre have unique psychological addiction potentials that are different from others and that this influences both game selection and internet use.  相似文献   
975.
With the advent of the Internet era and the maturation of electronic commerce, strategic avatar design has become an important way of keeping up with market changes and customer tastes. In this study, we propose a new approach to an adaptive avatar design that uses cognitive map (CM) as a what-if simulation vehicle. The main virtue of the new design is its ability to change specific avatar design features with objective consideration of the subsequent effects upon other design features, thereby enhancing user satisfaction. Statistical analyses of focus group interview results with a group of experts majoring in avatars and CM showed that our proposed approach could be used to effectively analyze avatar design in an adaptive and practical manner when the market situation is changing.  相似文献   
976.
This study deals with the impact of virtual reality (VR) features that are embedded in a hotel website on travelers' anxiety. Having more information is thought to be a factor in relieving anxiety in travel. A hotel website can be a good place for gathering information about the accommodation. In this study, we posit that a hotel website with VR functions should lead to a reduction in travelers' anxiety about travel. We built a website of a hotel and used VR functions to show the exterior, the lobby, a guest room, and a restaurant through an interactive and spatial shot of the hotel images. The experiment was conducted with a premise that the subjects were about to embark on a journey to an unknown place and to stay at an unknown hotel whose website contained VR functions. The subjects were asked to play with VR functions of the hotel website and then to complete a survey with questions regarding the degree of anxiety on the travel and psychological relief that might have been perceived by the subjects. The result confirms our hypothesis that there is a statistically significant relationship between the degree of travel anxiety and psychological relief caused by the use of VR functions of a hotel website.  相似文献   
977.
This article describes and accounts for variable interests in engineering ethics in France, Germany, and Japan by locating recent initiatives in relation to the evolving identities of engineers. A key issue in ethics education for engineers concerns the relationship between the identity of the engineer and the responsibilities of engineering work. This relationship has varied significantly over time and from place to place around the world. One methodological strategy for sorting out similarities and differences in engineers’ identities is to ask the “who” question. Who is an engineer? Or, what makes one an engineer? While engineering ethics has attracted little interest in France and formal education in the subject might be seen as redundant, German engineering societies have, since the conclusion of World War II, demanded from engineers a strong commitment to social responsibility through technology evaluation and assessment. In Japan, a recent flourishing of interest in engineering ethics appears to be linked to concerns that corporations no longer function properly as Japanese “households.” In each case, deliberations over engineering ethics emerge as part of the process through which engineers work to keep their fields in alignment with changing images of advancement in society.  相似文献   
978.
This article provides a critical qualitative analysis of popular mind-body-spirit books. Typically, these books present a hybrid combining spirituality with self-help and popular psychology. They promise to soothe, heal, and liberate the reader from what is construed as a mundane, desolate life and an environmental and social context of despair. Constructions of transformation and liberation are pervasive in these books. The analysis attends to meaning and rhetoric. Three discourses are delineated, each of which constructs transformation and liberation. In addition, while it is assumed that the authors produce a particular version of spirituality in these books rather than present the truth in a value-neutral way, this analysis attends to the rhetorical strategies that can work to make the authors’ message appear as literal and factual to the reader.  相似文献   
979.
The present study examined whether young children's behaviors in the Dimensional Change Card Sorting task can be influenced by their observation of another person performing the task. Experiment 1 showed that after children watched an adult sorting cards according to one rule, although the children were instructed to sort the cards according to a new rule, most 3-year-olds made perseverative errors and used the observed, old rule to sort the cards instead of the new rule. However, only some 4-year-olds and few 5-year-olds made the same mistake. Experiments 2, 3 and 4 showed that the younger children took into consideration social pragmatic information displayed by the adult model when deciding to use the old rule or the new rule. When the model appeared to know that she sorted the cards incorrectly (Experiments 2 and 3), or was uncertain whether she sorted cards correctly (Experiment 4), most 3-year-olds no longer committed perseverative errors. When the adult model was confident about her sorting or oblivious to her sorting errors, most 3-year-olds made perseverative errors. These results taken together suggest that social observation can lead to disinhibitions. In other words, disinhibition can be transmitted socially from one person to another.  相似文献   
980.
Social grooming in the kindergarten: the emergence of flattery behavior   总被引:1,自引:0,他引:1  
Fu G  Lee K 《Developmental science》2007,10(2):255-265
The present study examined the emergence of flattery behavior in young children and factors that might affect whether and how it is displayed. Preschool children between the ages of 3 and 6 years were asked to rate drawings produced by either a present or absent adult stranger (Experiments 1 and 2), child stranger (Experiments 2 and 3), classmate, or the children's own teacher (Experiment 3). Young preschoolers gave consistent ratings to the same drawing by the person regardless of whether the person was absent or present. In contrast, many older preschoolers gave more flattering ratings to the drawing when the person was present than in the person's absence. Also, older preschoolers displayed flattery regardless of whether the recipient was an adult or a child. However, they displayed flattery to a greater extent towards familiar individuals than unfamiliar ones, demonstrating an emerging sensitivity to social contexts in which flattery is used. These findings suggest that preschoolers have already learned not to articulate bluntly their true feelings and thoughts about others. Rather, they are able to manipulate their communications according to social context.  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