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981.
Physica is an integrated software package designed as part of a course for distance learning students from non-traditional educational backgrounds. It gives students access to an extensive hyperlinked physics glossary, computer algebra and graph-plotting tools. The package aims to give students a framework for solving physics problems and to help them acquire some higher level skills of quantitative problem-solving. This paper outlines rationales underlying various protocols for solving physics problems, and discusses the extent to which frameworks may be useful in helping students develop appropriate strategies for representing problems in formal terms, selecting targets, planning solutions and checking answers. Pedagogical issues underlying the design and implementation of the software are discussed.  相似文献   
982.
This study focused on combining both the group- and individual-level analyses in studying a collaborative activity in technology-enhanced interactions in a higher education setting. The aim was to make visible, with empirical examples, the quality of the students' web-based discussions and trace the route for shared understanding. By quantifying various communicative functions, the analysis provided general knowledge on the quality and purpose of the discussion in the group and highlighted the different functional positions each student had within the group. However, only a detailed interpretative analysis of the relationships between specific thematic contents, communicative functions, and the collaborative features of the discussion, in the temporal frame, made it possible to trace and gain a deeper understanding of the true acts of collaboration. It also highlighted the individual participants' different participatory and discursive positions in the different phases of the task. Over the study, it became evident that any attempts to define a collaborative activity from either the group's or individual's perspective would only result in a partial interpretation of the collaborative enterprise.  相似文献   
983.
In this article we first describe the past and current status of educational technology at New Jersey Institute of Technology (NJIT) (http://www.njit.edu). We then discuss the main points of deliberation for students, faculty and administrators involving learning via the World Wide Web and other information technologies, such as the Virtual Classroom TM (http://www.vc.njit.edu). Implementation and expansion of Web-based instructional activities at NJIT is occurring in all colleges of the university. In the Computer and Information Science (CIS) and Humanities and Social Sciences (HSS) departments, there is an ongoing and concerted effort to find practical applications of technology that meet educational ends. Such productive mergers highlight the complex issues that exist among instructional staff, administrative concerns and distance learning technologies. We conclude with a suggestion as to how such activity, in concert with a more developed communications tec hnology infrastructure, can serve to enhance the educational experience and outcomes of NJIT students.  相似文献   
984.
In this paper we study a multi-channel network, each station of which is equipped with a network interface that has a receiver buffer of multiple packets. In this way, each station is able to receive multiple packets per time instant. We adopt a synchronous access protocol which is affected by the collisions over the multiple channels and the destination conflicts. The proposed protocol performance crucially depends on the size of the receiver buffer since it determines the packet rejection probability at destination. An analytical probabilistic model based on a Markovian process is adopted for the performance measures derivation by means of closed mathematical formulas. The proposed protocol is compared to relative ones that either totally ignore the receiver collisions or assume a receiver buffer of a single packet capacity. The numerical results show that the increase of the receiver buffer size improves the performance decisively, resulting in higher throughput and lower delay and rejection probability. Also, it is shown that the appropriate receiver buffer size per station in order for the rejections at destination to be effectively eliminated is not unlimited but is limited to three packets for 0.1% accepted maximum level of rejection probability.  相似文献   
985.
986.
A vast literature on technology transitions within industries suggests that early phases of new technologies are marked by periods of intense experimentation, but we know little about the conditions under which these periods emerge. We apply inductive, grounded theory-building techniques to examine what prompts firms to experiment across one emerging technology platform—plug-in electric vehicles (PEVs)—in China. Triangulating annual vehicle make and model sales data from 2003 to 2016 (plus monthly data from 2010 to 2016); 112 English and Mandarin archival documents from industry, academic, and news outlets; and 51 semi-structured interviews with industry, government, and academic stakeholders, we develop four in-depth case studies. We find that in contrast to the innovation trajectories of multinational and Chinese arms of joint venture (JV) firms, independent domestic Chinese firms (those with no history of international JV partnerships) are undertaking significant experimentation across multiple levels—infrastructure, core system, subsystem, and component—of the emerging PEV technology platform. We propose the concept of “institutional complementarities” to describe how interactions among institutions—here the national JV regulation and local market support and subsidies—may have turned regional markets into protected laboratories, extending the incubation periods for independent domestic firm experimentation. While this diverse experimentation may be an important antecedent of technology transition, consolidation induced by national policy standardization or competitive pressure may be required for PEV innovations to scale beyond their early, protected regional markets.  相似文献   
987.
Science is increasingly a team activity, and the size of the teams has been growing. At the same time, there are concerns about an increasing rate of pathologies in science. The growth of team science suggests the need to look beyond individual-level explanations and focus on organizational structures and institutional contexts to explain pathologies in science. Drawing on the literature on organizational pathologies, we argue that division of labor may be a key factor contributing to pathologies in science. Furthermore, we examine the effects of high-stakes incentives and of institutional corruption as additional predictors of scientific pathologies. Using retractions as an indicator of pathologies, and drawing on a matched sample of 195 retracted papers and 349 paired papers that were not retracted, we develop indicators of the division of labor in the team that produced a paper and find that the rate of retractions is higher as the division of labor increases (net of team size). Additionally, we find that high-stakes incentives and institutional corruption are also associated with increased retractions. We conclude with a discussion of the implications of these findings for science policy, in particular for organizing team science projects.  相似文献   
988.
989.
Trajectories of adjustment were examined in a sample of street-involved youth across a 1-year period. Participants (N = 113; Mage = 14.18 years; 80.5% male, 91% non-White) were recruited in three Brazilian cities. Interviews conducted at three time points included six measures of physical and psychological adjustment. Unconditional growth models revealed linear declines over time (i.e., improved adjustment) on three indicators: health symptoms, sexual risk behaviors, and negative affect. There were no linear changes in drug use, positive affect, or life satisfaction. Conditional growth models revealed few significant effects for age or gender, but ratings of stressful life events moderated longitudinal changes in health symptoms, drug use, and negative affect. Implications for practice, policy, and theory are discussed.  相似文献   
990.
In an era of teacher quality reforms, one overlooked area for assessing readiness for teaching is education majors’ self‐efficacy for teaching reading. This gap is unfortunate, as teaching reading is a common responsibility among general and special education teachers. In the current push for RTI—one in which more general education teachers are increasingly called upon to provide reading support to students with learning disabilities, in addition to the support received from special educators—it is important to determine preservice teachers’ self‐efficacy for teaching reading. Self‐efficacy is an important construct to consider as it is related to eventual teacher attrition. The purpose of the current study was to develop a scale to measure elementary and special education majors’ self‐efficacy for teaching reading. With a sample of 110 education majors, a three‐factor scale was developed and demonstrated strong psychometric properties. Implications for the future of teacher education programs are discussed.  相似文献   
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