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   1678篇
  免费   27篇
  国内免费   4篇
教育   1361篇
科学研究   41篇
各国文化   22篇
体育   81篇
文化理论   8篇
信息传播   196篇
  2023年   8篇
  2022年   6篇
  2021年   25篇
  2020年   27篇
  2019年   46篇
  2018年   75篇
  2017年   64篇
  2016年   60篇
  2015年   42篇
  2014年   48篇
  2013年   382篇
  2012年   45篇
  2011年   55篇
  2010年   40篇
  2009年   41篇
  2008年   53篇
  2007年   59篇
  2006年   48篇
  2005年   42篇
  2004年   16篇
  2003年   31篇
  2002年   41篇
  2001年   24篇
  2000年   29篇
  1999年   31篇
  1998年   20篇
  1997年   25篇
  1996年   28篇
  1995年   20篇
  1994年   27篇
  1993年   31篇
  1992年   21篇
  1991年   17篇
  1990年   19篇
  1989年   16篇
  1988年   8篇
  1987年   9篇
  1986年   14篇
  1985年   12篇
  1984年   9篇
  1983年   12篇
  1982年   5篇
  1980年   6篇
  1979年   8篇
  1978年   8篇
  1977年   11篇
  1975年   9篇
  1974年   9篇
  1973年   3篇
  1969年   3篇
排序方式: 共有1709条查询结果,搜索用时 15 毫秒
11.
12.
Abstract

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340?kcal?d?1 and 452?kcal?d?1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300?kcal?d?1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500?kcal?d?1 and obese women an increase of 0, 450 and 350?kcal?day?1. The recommendations for carbohydrate and protein intake are 175?g?d?1 and 0.88–1.1?g?kgBM?d?1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8–11.3?kg and obese women 5.0–9.1?kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5–16.0?kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.  相似文献   
13.
14.
Reflections about the use of critically reflexive praxis by academic/practitioners are offered based on a case study of a formative evaluation of Circles® USA, a nonprofit organization coordinating initiatives across the U.S. working to move families out of poverty. Critically reflexive praxis is theorized as featuring several themes including acknowledging different levels of context, critical dialogue with collaborators, engaging cultural difference and intersectionalities, problematizing power relations and relationships among researchers and collaborators, and occurring throughout the research project. Examples of critical dialogic reflexivity and navigating common tensions that emerge throughout such community engagement projects are detailed during three phases: planning and design; fieldwork and interviews; and outcomes, applications, and implications.  相似文献   
15.
This paper examines the effect of modifiers on the stability of a vinyl acetate/ethylene copolymer dispersion adhesive upon aging. Eighteen common modifiers were added to a well-characterized vinyl acetate/ethylene copolymer dispersion (Dur-O-Set® E-150) in known concentrations and dry-film samples were subjected to 16–17 years of dark aging and seven to eight years of light aging. Yellowing, pH, gloss, swelling, cohesive strength, and flexibility were monitored for changes upon aging. Generally, the neat Dur-O-Set® E-150 (no additives) was found to become acidic on aging, but was fairly resistant to yellowing. It also swelled substantially in toluene, was of high gloss, medium strength, and flexible, and remained so on aging. No modifier was found to improve these properties. Various solvents, wetting agents, and thickeners did not alter the properties by much, while plasticizers, freeze-thaw stabilizer, glycerin, and certain fillers had a more negative effect.  相似文献   
16.
An analysis of the impact of stakeholder consultation during the conservation decision-making processes is presented. Defining and finding opportunities for stakeholder communication within conservation work is an ethical necessity when working with cultural heritage, but the limits and practice of this necessity are less clear. Case studies are used to explore which aspects of the conservation process stakeholders are most likely to be consulted about, and reviews the impact of their views. It asks whether conservators have a preference in which decisions they are prepared to share with stakeholders across three aspects of conservation: the initial appraisal, treatment and the display or storage. Where consultation relates to treatment, conservators are more likely to fall back on their own technical authority except when those consulted are regarded as fellow professionals. Other categories of stakeholder such as artists, originating communities, and religious groups were found to be more constructively consulted on the understanding of the object and on care related to display and storage. Conservators should be offered more explicit guidance on the ethics of consultation, the aspects of consultation that they should engage with and on the ethical ways to deal with conflict arising from consultation.  相似文献   
17.
Decisions about preservation issues are made both deliberatively and unconsciously. Heuristics operate as intuitive processes which are rapid and can be reliable and effective. Deliberative decisions require time to complete and can be described by an analytic-deliberative model. The characteristics of these two processes and their relevance to preventive conservation decision-making are discussed. Each of these two processes has its strengths and weaknesses. People naturally make decisions and utilise a range of strategies without necessarily having insights into the process. This paper provides a frame to help examine, describe, and reflect upon our own and others’ decision-making in order to improve both processes and outcomes.  相似文献   
18.
19.
20.
The relationships between team performance indicators and match outcome have been examined in many team sports, however are limited in Australian Rules football. Using data from the 2013 and 2014 Australian Football League (AFL) regular seasons, this study assessed the ability of commonly reported discrete team performance indicators presented in their relative form (standardised against their opposition for a given match) to explain match outcome (Win/Loss). Logistic regression and decision tree (chi-squared automatic interaction detection (CHAID)) analyses both revealed relative differences between opposing teams for “kicks” and “goal conversion” as the most influential in explaining match outcome, with two models achieving 88.3% and 89.8% classification accuracies, respectively. Models incorporating a smaller performance indicator set displayed a slightly reduced ability to explain match outcome (81.0% and 81.5% for logistic regression and CHAID, respectively). However, both were fit to 2014 data with reduced error in comparison to the full models. Despite performance similarities across the two analysis approaches, the CHAID model revealed multiple winning performance indicator profiles, thereby increasing its comparative feasibility for use in the field. Coaches and analysts may find these results useful in informing strategy and game plan development in Australian Rules football, with the development of team-specific models recommended in future.  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