全文获取类型
收费全文 | 61558篇 |
免费 | 2060篇 |
国内免费 | 717篇 |
专业分类
管理学 | 1928篇 |
劳动科学 | 9篇 |
民族学 | 905篇 |
人才学 | 13篇 |
人口学 | 740篇 |
丛书文集 | 7883篇 |
理论方法论 | 2457篇 |
综合类 | 45299篇 |
社会学 | 3240篇 |
统计学 | 1861篇 |
出版年
2024年 | 115篇 |
2023年 | 358篇 |
2022年 | 489篇 |
2021年 | 643篇 |
2020年 | 815篇 |
2019年 | 808篇 |
2018年 | 759篇 |
2017年 | 930篇 |
2016年 | 993篇 |
2015年 | 1273篇 |
2014年 | 3097篇 |
2013年 | 3934篇 |
2012年 | 3935篇 |
2011年 | 4535篇 |
2010年 | 3629篇 |
2009年 | 3706篇 |
2008年 | 3858篇 |
2007年 | 4657篇 |
2006年 | 4657篇 |
2005年 | 4173篇 |
2004年 | 3891篇 |
2003年 | 3836篇 |
2002年 | 3151篇 |
2001年 | 2682篇 |
2000年 | 1450篇 |
1999年 | 444篇 |
1998年 | 259篇 |
1997年 | 192篇 |
1996年 | 168篇 |
1995年 | 126篇 |
1994年 | 88篇 |
1993年 | 100篇 |
1992年 | 82篇 |
1991年 | 83篇 |
1990年 | 39篇 |
1989年 | 74篇 |
1988年 | 20篇 |
1987年 | 26篇 |
1986年 | 27篇 |
1985年 | 28篇 |
1984年 | 62篇 |
1983年 | 38篇 |
1982年 | 39篇 |
1981年 | 10篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1978年 | 14篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 295 毫秒
991.
In chemical and microbial risk assessments, risk assessors fit dose‐response models to high‐dose data and extrapolate downward to risk levels in the range of 1–10%. Although multiple dose‐response models may be able to fit the data adequately in the experimental range, the estimated effective dose (ED) corresponding to an extremely small risk can be substantially different from model to model. In this respect, model averaging (MA) provides more robustness than a single dose‐response model in the point and interval estimation of an ED. In MA, accounting for both data uncertainty and model uncertainty is crucial, but addressing model uncertainty is not achieved simply by increasing the number of models in a model space. A plausible set of models for MA can be characterized by goodness of fit and diversity surrounding the truth. We propose a diversity index (DI) to balance between these two characteristics in model space selection. It addresses a collective property of a model space rather than individual performance of each model. Tuning parameters in the DI control the size of the model space for MA. 相似文献
992.
《Omega》2017
Tactical production-distribution planning models have attracted a great deal of attention in the past decades. In these models, production and distribution decisions are considered simultaneously such that the combined plans are more advantageous than the plans resolved in a hierarchical planning process. We consider a two-stage production process, where in the first stage raw materials are transformed into continuous resources that feed the discrete production of end products in the second stage. Moreover, the setup times and costs of resources depend on the sequence in which they are processed in the first stage. The minimum scheduling unit is the product family which consists of products sharing common resources and manufacturing processes. Based on different mathematical modelling approaches to the production in the first stage, we develop a sequence-oriented formulation and a product-oriented formulation, and propose decomposition-based heuristics to solve this problem efficiently. By considering these dependencies arising in practical production processes, our model can be applied to various industrial cases, such as the beverage industry or the steel industry. Computation tests on instances from an industrial application are provided at the end of the paper. 相似文献
993.
994.
思想政治教育是我国学校教育的重要内容,思想政治工作是学校工作的重要组成部分。学生思想政治教育为学生素质拓展提供了强大的精神动力和智力支持。在实施学生素质拓展计划的过程中,学生思想政治教育始终处于主导性地位,对学生素质拓展计划的实施具有极其重要的作用。 相似文献
995.
Tony Bovaird 《Social Policy & Administration》2014,48(1):1-23
In recent years there has been increased interest in outcome‐based social policy‐making and management. The UK has been in the forefront of this movement but similar movements have been identified internationally. This interest in outcome‐based decision‐making has been given particular impetus through the ‘results’‐based movement in evaluation and performance management since the 1980s, which has increased in scope over time, slowly changing its emphasis from cost reduction and measuring outputs to measuring outcomes. This change has been widely welcomed by policymakers, practitioners and academics. However, there is evidence that the reality is often rather less than the rhetoric. Moreover, the ‘attribution problem’ of attributing changes in outcomes to specific social policies has remained a major issue. The conceptual solution of constructing ‘cause‐and‐effect’ models, imported from the policy evaluation field, has only recently become common for operationalising these models. This article outlines the evolution of interest in outcome‐based social policy‐making up to recent times and the growing realization of the importance of the attribution problem. It then outlines both how the ‘cause‐and‐effect’ policy modelling approach can partially tackle the attribution problem, but also its inherent limitations. Lastly, the article uses several case studies in current UK social policy‐making to demonstrate the potential importance of the reasoning embedded within cause‐and‐effect models but also the dangers in policy‐making which adopts this approach without understanding its conceptual basis or in fields where it is inappropriate, given the current state of our knowledge of social policy systems. 相似文献
996.
第二次世界大战后,日本制定了具有本国特色的科技政策,并将科技政策纳入国家政策体系之中。其中,科技研发思路是制定科技政策的关键性步骤;政府对科技研发的保障性投入,也属于科技政策的重要组成部分。日本是当今世界科技和经济大国,探析并总结其战后科技研发思路及资金保障的经验教训,对后进国家制定科技发展战略无疑具有重要的借鉴和启示作用。 相似文献
997.
《Journal of homosexuality》2012,59(6):776-789
An ongoing fear in the gay and lesbian community is that long-term care (LTC) facilities may not be sensitive to their needs. In the present study, 218 LTC staff members responded to one of three vignettes in which resident sexual contact was observed, with only the gender of the characters changing, to create different gender pairings. Results suggested that staff rated male-male and female-female pairings more negatively than heterosexual intimacy. Knowledge about older adult sexuality made little difference in staff ratings. However, staff attitudes were directly related to ratings of negative reaction and level of acceptability of same-gender sexuality. 相似文献
998.
Sumith Gunasekera 《统计学通讯:模拟与计算》2017,46(2):933-947
The Theil, Pietra, Éltetö and Frigyes measures of income inequality associated with the Pareto distribution function are expressed in terms of parameters defining the Pareto distribution. Inference procedures based on the generalized variable method, the large sample method, and the Bayesian method for testing of, and constructing confidence interval for, these measures are discussed. The results of Monte Carlo study are used to compare the performance of the suggested inference procedures from a population characterized by a Pareto distribution. 相似文献
999.
Objective: To discuss the potential of a café on the premises of an aged-care facility as a vehicle for culture change. Method: Secondary analysis of primary qualitative data that explored the value of a café in an aged-care facility, compared with culture-change principles established from a literature review. Results: Secondary analysis established congruence between culture-change principles and the themes established in the primary qualitative data. A café, in one aged-care facility, has facilitated the following dimensions of culture change for residents: individualized care, facilitation of meaningful relationships, opportunities for participation in life roles, and creation of a sense of belonging. Conclusion: Culture change can be achieved through environmental innovations, such as a café, where food and dining maximize social opportunities and create a homelike environment that facilitates continuation of residents' identity. 相似文献
1000.
通过中国儒家和西方经济价值结构的比较研究,发现儒家以“义一利”为价值结构模型,西方以“财富”为价值结构模型。儒家价值结构的基本特征是“义体利用”,表现方式是:强国的道义在于顺天时、尽地利、忠人和;安国的道义在于民朴民富;治国的道义在于蓄储俭用。西方价值结构的基本特征是“利体义用”,表现方式是:鼓励获取财富、财富规则和财富责任。儒家“义一利”价值结构与西方“财富”价值结构是两种不同的价值评判话语体系,在中国现代“义利共体”的价值结构建构中,儒家价值结构提供着人文精神基础,西方价值结构提供着物质文明建设可资借鉴的经验。 相似文献