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1.
Jonathan J. Mallett 《Learned Publishing》2021,34(1):49-56
- Scientific publication has been a key part of the scientific method since the inception of Philosophical Transactions in 1665.
- The scientific publications industry has grown exponentially along with science, incorporating technological innovations along the way, and adapting journal processes and practices to changing needs of science as it matured.
- Of all the technological innovations over more than 300 years, the move to online journals may be the most significant, making open access to content practical for the first time.
- The open‐access movement is disrupting the economics of journal publishing, which is hoped will make the industry more competitive: the ability of the publications industry to adapt to open access will be a measure of its resilience.
- The demand for articles published in reputable journals continues to grow as readers trust the credibility of peer reviewed journal articles, and good authors value the prestige of publishing in the best journals.
- It is difficult to predict what new functionalities may be included in articles of the future or what additional services publishers and editors will provide, but there is every reason to believe that scientific journal articles are here to stay.
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The graph-theoretic field model— II. application of multi-terminal representations to field problems
This paper is a sequel to a paper entitled “The Graph-Theoretic Field Model—I: Modelling and Formulations” (1). Herein, the Theory of Multi-Terminal Representations is applied to the Graph-Theoretic Field Model to provide mathematical models of finite elements. The element models are obtained solely from the algebraic building blocks of the Graph-Theoretic Field Model, without recourse to any functional mathematics. The theory of Multi-Terminal Representations is developed for both linear and non-linear problems. Examples of the application of the theory to one- and two-dimensional field problems are presented from heat conduction and electrostatics. 相似文献
4.
The Graph-Theoretical Field Model provides a unifying approach for developing numerical models of field and continuum problems. The methodology examines the field problem from the first stages of conceptualization without recourse to the governing differential equations of the field problem; this is accomplished by deriving discrete statements of the physical laws which govern the field behaviour. There are generally three laws, and these are modelled by the “cutset equations”, the “circuit equations”, and the “terminal equations”. In order to establish these three sets of equations it is expedient first to spatially discretize the field in a manner similar to the finite difference method and then to associate a linear graph (denoted as the field graph) with the spatial discretization. The concept of “through” and “across” variables, which underlies the cutset and circuit equations respectively, enables one to define the graph in an unambiguous manner such that each “edge” of the graph identifies a pair of complementary variables. From a knowledge of the constitutive properties and the boundary conditions of the field it is possible to associate terminal equations with sets of edges. Since the resulting sets of equations represent the field equations, these equations provide the basis for a complete (but approximate) solution to the field or continuum problem. In fact, this system approach uses a two part model: one for the components and another for the interconnection pattern of the components which renders the formulation procedures totally independent of the solution procedure.This paper presents the theoretical basis of the model and several graph-theoretic formulations for steady-state problems. Examples from heat conduction and small- deformation elasticity are included. 相似文献
5.
Arterial spin labelling (ASL) provides a potential method to non-invasively determine muscle blood flow and examine the impact of interventions such as supplementation and training. However, it's a method with intrinsically low signal, leading to limitations in accuracy and temporal resolution. To examine these limitations, the current study measured perfusion via ASL on three occasions in the rectus femoris of 10 healthy adults, during light and moderate exercise, over three different exercise durations. For data sampled over 9 min, light intensity exercise gave an average perfusion of 35.0 ± 5.1 ml/min.100g?1 with a coefficient of variation (COV) of 16% and single intraclass correlation coefficient (ICC) of 0.67. For the moderate bout, perfusion was 51.3 ± 5.6 ml/min.100g?1 (COV 10%, ICC 0.82). When the same data were analyzed over 5 min 24 s, perfusion was 37.8 ± 11.13 (COV 30%, ICC 0.13) during light and 49.5 ± 8.8 ml/min.100g?1 (COV 18%, ICC 0.52) during moderate exercise. When sampling was reduced to 1 min 48 s, perfusion was 41.2 ± 13.7 (COV 33%, ICC 0.26) during light and 49.5 ± 13.6 ml/min.100g?1 (COV 28%, ICC 0.04) during moderate exercise. For 9 min a significant perfusion difference was found between the exercise intensities; however, this was not the case for sampling over 5 min 24 s or 1 min 48 s. Such findings illustrate the potential of ASL to non-invasively monitor muscle perfusion under steady-state conditions, but highlight that extended exercise protocols are necessary in order to generate date of sufficient reliability to be able to discriminate intervention dependent perfusion differences. 相似文献
6.
Gerald J. Savage 《Technical Communication Quarterly》1996,5(3):309-327
As we increasingly recognize the social nature of technical communication, our responsibilities as teachers need to be redefined. Three levels of responsibility are suggested: at the theoretical level, we should study technical communication as a historically emergent social practice; at the pedagogical level, we need to incorporate social and historical perspectives into technical communication courses and curricula; at the level of social action, we should participate in defining and creating new sites of practice for technical communicators. Several suggestions are offered for helping students locate or develop alternative sites of technical communication practice. 相似文献
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- 1 Summaries
- 2 Reflections
8.
Jonathan R. Brown 《Psychology in the schools》1992,29(2):179-184
Meta-analysis is an analysis of analyses. It is a technique widely used by researchers and practitioners to aggregate and summarize statistically reported empirical educational research. In 10 years, meta-analysis appeared more than 600 times in research journals and dissertation abstracts. Although most meta-analyses were reported as significant, few of the findings determined how many unpublished “no-effect” studies, if sampled, would have invalidated significance. If significant meta-analysis results are over represented through selective sampling, hucksterism in the form of sampling bias exists. An explanation for using a follow-up test called the fail-safe N is provided with tables constructed to assist researchers and practitioners to estimate, without calculation, the relative stability of meta-analysis results. The implication is that failsafe N should routinely be used and reported in meta-analysis research. 相似文献
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Jonathan Sandoval 《Psychology in the schools》1982,19(3):310-314
Light's Retention Scale totals, along with measures of reading achievement, mathematics achievement, and self-concept taken at the time first grade nonpromotion was being considered, were used to predict nine separate outcome measures of academic, emotional, and social status at the end of the repeated first grade. In none of the stepwise regressions did the Light total add to the prediction of outcome in the children repeating the first grade. This result, added to earlier studies, suggests that Light's Retention Scale is neither reliable nor valid as a psychometric device. 相似文献