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151.
Abstract

In many countries agriculture is in a process of rapid change,
  • - it has to meet a growing demand for food in a sustainable way,

  • - the international competition is increasing,

  • - the increase in labour productivity is decreasing the employment opportunities in agriculture,

  • - agricultural research is offering many new opportunities to increase productivity,

  • - government price support for agricultural products in industrial countries is decreasing.

These changes have many implications for agricultural extension, such as:
  • - the knowledge and capabilities of farmers has become a major factor in their ability to compete in national and international markets,

  • - advice is not only needed on the adoption of new technologies, but also on many other decisions farmers have to make, such as the choice of their farming system and the decision whether or not to earn an income from outside agriculture,

  • - this requires a change in extension methods and in the information sources extension agents use,

  • - agricultural development demands painful changes in the way of farming and of living for many farm families. It is a challenge for extension agencies to help farm families to realise this,

  • - a major task for leaders of extension organisations is to manage a process of change in agricultural extension. Often the role extension has to play in agricultural development can not be performed by one extension organisation, but only by a pluralistic extension system.

Agricultural extension is often expected to contribute to a reduction of poverty among farmers and farm labourers. One has to think seriously how one can realise this objective.  相似文献   
152.
Abstract

The paper describes the results of an exploratory study of farmers’ reasons for changing or not changing to more sustainable production methods in arable farming in the Netherlands. The background of the research is the disappointing adoption of Integrated Arable Farming Systems (iafs). Perceived production risk was expected to be an important factor constraining adoption. This study suggests, however, that perceived risk is not a satisfactory explanation. One reason is that iafs as it has become in Dutch practice cannot be easily distinguished from conventional arable farming systems. A continuum of gradual adoption of iafs methods, mainly for economic reasons, was observed. A real watershed difference was observed between partial adopters of iafs and organic farmers who used no chemicals at all. Secondly, dealing with production risks, such as weather‐dependent problems with weeds, pests and diseases, is considered part of professionalism of both conventional and iafs farmers and hence not a reason for avoiding a specific crop husbandry technique. However, uncertainties emanating from market conditions and environmental policy were found to be important considerations. JAgr Educ Ext (2001, 7, 3, pp 153–166)  相似文献   
153.
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156.
Researchers often have expectations that can be expressed in the form of inequality constraints among the parameters of a structural equation model. It is currently not possible to test these so-called informative hypotheses in structural equation modeling software. We offer a solution to this problem using Mplus. The hypotheses are evaluated using plug-in p values with a calibrated alpha level. The method is introduced and its utility is illustrated by means of an example.  相似文献   
157.
In this article we present factor models to test for ability differentiation. Ability differentiation predicts that the size of IQ subtest correlations decreases as a function of the general intelligence factor. In the Schmid–Leiman decomposition of the second-order factor model, we model differentiation by introducing heteroscedastic residuals, nonlinear factor loadings, and a skew-normal second-order factor distribution. Using marginal maximum likelihood, we fit this model to Spanish standardization data of the Wechsler Adult Intelligence Scale (3rd ed.) to test the differentiation hypothesis.  相似文献   
158.
This study investigated the growth of word-decoding skills throughout the elementary school years for a representative sample of 2,819 Dutch children. Children's decoding abilities for (a) regular consonant-vowel-consonant words, (b) complex monosyllabic words with consonant clusters in prevocalic and postvocalic position, and (c) polysyllabic words were assessed on two occasions in each school year (Grades 1–6). The growth of word-decoding skills was found to be largely a matter of increased speed. Growth curve analyses showed a gradual curvilinear model to be superior to a step-model for all word-decoding skills. Furthermore, the three measures of word decoding define a common factor and show strong longitudinal stability. Some unique variance for the three word-decoding skills also emerged suggesting that the development of fully proficient word-decoding skills requires the learning of orthographic complexities.  相似文献   
159.
In this paper, techniques from the research field of knowledge management are used to improve the maturity of the Computer Based Training (CBT) development process at an IT-oriented organization involved in producing courseware. The project team is facilitated with a knowledge-sharing solution that enables them to unambiguously define their project process, and link templates and best practices to the activities in that process. In addition, a virtual discussion room is provided for them to share new insights. Results from measurement experiments indicate more positive project experiences with projects that used the knowledge-sharing solution.  相似文献   
160.
The Teachers of Promise study has followed the work histories of 57 primary and secondary teachers who had been identified at the beginning of their third year of teaching as having the potential to make a significant contribution to the profession. Using data from surveys and interviews, this paper reports on what sustained or inhibited their initial commitment to and enthusiasm for ‘making a difference’, six years later, both in the classroom and in broader school leadership roles. Satisfaction with their day-to-day experiences in their schools was a particularly strong driver of teachers’ career decisions over time. Thirty-four teachers responded to survey items that were used to identify three different groups of teachers: a group of 10 primary school teachers with the highest levels of job satisfaction who were ‘fulfilling their promise’; a group of 21 primary and secondary teachers who were ‘persevering and coping’; and three teachers who were ‘detached and disengaged’. The group with the highest levels of job satisfaction taught in primary schools where they felt respected and valued, and supported to develop their teaching and leadership expertise. School leadership practices and school cultures in the other two groups diminished teachers’ overall job satisfaction and contribution to collective knowledge building in their schools. Almost all of the teachers had retained their commitment to students, to their current schools and to teaching as a career, including those with lower levels of satisfaction. Although these teachers reported ‘collegial’ relationships with their peers, individualistic school cultures, most often in secondary schools, impacted on their opportunities to learn with and from their colleagues. Few secondary school teachers felt appreciated, and included in school decision-making or had found it possible to combine high standards of classroom teaching with management responsibilities. The study indicates that while most promising teachers were still satisfied with teaching after nine years, relatively few were in schools where they were able to make the impact that had been predicted for them early in their careers.  相似文献   
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