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   23030篇
  免费   363篇
  国内免费   15篇
教育   16437篇
科学研究   2041篇
各国文化   221篇
体育   1908篇
综合类   13篇
文化理论   177篇
信息传播   2611篇
  2022年   181篇
  2021年   262篇
  2020年   382篇
  2019年   606篇
  2018年   829篇
  2017年   811篇
  2016年   707篇
  2015年   424篇
  2014年   660篇
  2013年   4449篇
  2012年   642篇
  2011年   647篇
  2010年   475篇
  2009年   487篇
  2008年   541篇
  2007年   481篇
  2006年   427篇
  2005年   411篇
  2004年   371篇
  2003年   358篇
  2002年   344篇
  2001年   477篇
  2000年   395篇
  1999年   361篇
  1998年   204篇
  1997年   211篇
  1996年   242篇
  1995年   235篇
  1994年   181篇
  1993年   200篇
  1992年   323篇
  1991年   298篇
  1990年   299篇
  1989年   298篇
  1988年   256篇
  1987年   301篇
  1986年   266篇
  1985年   305篇
  1984年   246篇
  1983年   211篇
  1982年   191篇
  1981年   163篇
  1980年   155篇
  1979年   258篇
  1978年   182篇
  1977年   168篇
  1976年   153篇
  1975年   141篇
  1974年   148篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
This paper provides an in-depth analysis of the privacy rights dilemma surrounding radio frequency identification (RFID) technology. As one example of ubiquitous information system, RFID has multitudinous applications in various industries and businesses across society. The use of this technology will have to lead to a policy setting dilemma in that a balance between individuals’ privacy concerns and the benefits that they derive from it must be drawn. After describing the basic RFID technology some of its most prevalent uses, a definition of privacy is derived in the context of information systems. To illustrate current attempts at controlling the undesirable side effects of RFID, Lessig’s cyberspace framework is presented. It is found that each of Lessig’s components is inadequate at preventing individual privacy violations in RFID. The main focus within this framework is on the norms of society. The social norm mechanism that addresses privacy issues in cyberspace is the Fair Information Practices Principles (FIPP). After an analysis of these principles, it is posited that the FIPP only deal with procedural justice issues related to data collection and omit distributive and interactional justice reasoning related to the actual beneficial and detrimental outcomes to the individuals whose data is being obtained. Thus, RFID is presented in the context of the tension between the many benefits that are provided by the technology in social exchanges, and the risk it carries of the loss of privacy. The new, expanded framework recognizes both sides of the issue with the ultimate goal of providing a greater understanding of how privacy issues can be addressed with RFID technology.  相似文献   
992.
993.
In recent years, the advent of low-cost digital and mobile devices has led to a strong expansion of social interventions, including those that try to improve student learning and literacy outcomes. Many of these are focused on improving reading in low-income countries, and particularly among the most disadvantaged. Some of these early efforts have been called successful, but little credible evidence exists for those claims. Drawing on a robust sample of projects in the domain of mobiles for literacy, this article introduces a design solution framework that combines intervention purposes with devices, end users, and local contexts. In combination with a suggested set of purpose-driven methods for monitoring and evaluation, this new framework provides useful parameters for measuring effectiveness in the domain of mobiles for literacy.  相似文献   
994.
Two preregistered experiments with 2,733 U.S. high school students (age range = 13–19 years) compared the impact of different messages on adolescents’ motivation to control social media use (SMU). A traditional message emphasized the benefits of avoiding SMU, whereas a values-alignment message framed controlling SMU as being consistent with autonomy and social justice. Compared to no message or a traditional message, in both studies, a values-alignment message led to greater motivation to control SMU immediately afterward, and in Study 2, awareness of “addictive” social media designs 3 months later. As hypothesized, values-alignment messaging was more motivating for girls than boys. Results offer preliminary support for leveraging adolescents’ drives for autonomy and social justice to motivate self-regulation of SMU.  相似文献   
995.

Analysis of competitive sport performance from a priori observation is frequently used to prepare an athlete for a future contest. This practice necessarily assumes that the observed athletic behaviours are invariant, in that the data from an earlier contest apply to the next. We report different analyses of championship squash matches from 1987 and 1988 in search of such invariance and thus a general signature of athletic behaviour. The results show that once the preceding condition to an athletic response (shot) becomes more detailed, by either accounting for where on court the previous shot was played to, or by pairing the previous shot with its own antecedent, the corresponding response becomes more predictable (P > 0.25). This is especially the case for a squash champion when the forehand and backhand characteristics of his shot response are accounted for. The finding that the champion is more consistent if his forehand and backhand shot responses to a preceding shot are analysed separately, shows that the level of analytic detail is an important consideration if the derived information from sport analysis is to prepare an athlete reliably for future sport competition. Finally, we consider sport competition from an ecological perspective with regard to the natural organization and stability of non‐linear systems in an attempt to explain the empirical data.  相似文献   
996.
Abstract

The purpose of this study was to determine if factor patterns of selected sports skills were similar for two samples, a skilled sample and one consisting of a wide range of skills. Comparisons were also made with kinesiological evidence regarding the patterning of basic sports skills. Data consisting of performance scores on various sports skills were available for 166 high school girls. Out of this sample, a smaller sample was drawn consisting of 69 girls who were above average in skill. Two factor models, alpha and incomplete image analysis, were used in the analysis of this data. The factor pattern of selected sports skills performed by subjects above average in skill was similar in many respects to that of a sample which included a wide range of skill. The primary difference lay in the clustering of overarm skills which appeared in the above-average factor pattern. The overarm and push patterns of the above-average sample resembled the patterns of skill obtained through kinesiological analysis. The structure of kicking, underarm, and sidearm skills remained obscure, based on the results of factor analytic techniques.  相似文献   
997.
ABSTRACT

The purpose was to quantify the effects of mid-flight whole-body and trunk rotation on knee mechanics in a double-leg landing. Eighteen male and 20 female participants completed a jump-landing-jump task in five conditions: no rotation, testing leg ipsilateral or contralateral (WBRC) to the whole-body rotation direction, and testing leg ipsilateral (TRI) or contralateral to the trunk rotation direction. The WBRC and TRI conditions demonstrated decreased knee flexion and increased knee abduction angles at initial contact (2.6 > Cohen’s dz > 0.3) and increased peak vertical ground reaction forces and knee adduction moments during the 100 ms after landing (1.7 > Cohen’s dz > 0.3). The TRI condition also showed the greatest knee internal rotation angles at initial contact and peak knee abduction and internal rotation angles and peak knee extension moments during the 100 ms after landing (2.0 > Cohen’s dz > 0.5). Whole-body rotation increased contralateral knee loading because of its primary role in decelerating medial-lateral velocities. Trunk rotation resulted in the greatest knee loading for the ipsilateral knee due to weight shifting and mechanical coupling between the trunk and lower extremities. These findings may help understand altered trunk motion in anterior cruciate ligament injuries.  相似文献   
998.
The present study examined the relationship between students’ perceptions of distributive and procedural justice in a college course and student motivation concerning the course, affective learning in the course, and aggression toward the course instructor. Although student perceptions of both distributive and procedural justice were positively correlated with student motivation and affective learning and negatively correlated with student aggression toward the course instructor, multiple regression analyses indicated that only perceptions of procedural justice predicted the three criterion variables at a statistically significant level while distributive justice perceptions did not. Implications and suggestions for future research in classroom justice are offered.  相似文献   
999.
Eighteen new counselor educators shared in‐depth reports of their efforts to establish an early record of scholarly productivity, critical to their success in academe. Analyses of their experiences using consensual qualitative research methods revealed components of both highly positive and highly discouraging program environments and their impact on participants’ research goals.  相似文献   
1000.
ABSTRACT

Introduction: Low energy availability (LEA) results in physiological adaptations, which can contribute to unfavourable health outcomes. Little information exists on risk of LEA in active individuals competing in different sports or levels of competition. The aims of this study were to (1) identify risk of LEA in females competing at different levels of competition and (2) investigate associations between risk of LEA, illness and dietary habits. Methods: The validated questionnaire, ‘Low Energy Availability in Females Questionnaire’ was distributed online (November 2016–February 2017) to assess risk of LEA. Twenty-nine additional questions collected information on demographics, illness history and dietary habits. Participants were considered at risk of LEA if they attained a score of?≥?8 and were grouped into: (i) international; (ii) provincial/inter-county; (iii) competitive; and (iv) recreationally active. Chi-square and logistic regression analyses were used to explore differences between those at risk or not at risk of LEA. Results: Risk of LEA was identified in 40% (n?=?331) of 833 participants and was 1.7 and 1.8 times more likely in international and provincial/inter-county athletes compared to those who were recreationally active (International: odds ratios (OR) 1.68, 95% confidence intervals (95%CI) 1.12–2.54; Provincial/inter-county: OR 1.83, 95%CI 1.20–2.77). In participants at risk of LEA, missing >22 days of training during the previous year due to illness occurred 3 times more frequently (OR 3.01, 95%CI 1.81–5.02). Conclusion: Risk of LEA was widespread in this heterogeneous sample. Awareness of LEA and the development of appropriate energy management strategies to ensure athlete health across levels of competition are required.  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