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   4758篇
  免费   177篇
  国内免费   54篇
管理学   620篇
劳动科学   1篇
民族学   37篇
人口学   239篇
丛书文集   390篇
理论方法论   243篇
综合类   2967篇
社会学   382篇
统计学   110篇
  2024年   17篇
  2023年   33篇
  2022年   41篇
  2021年   48篇
  2020年   81篇
  2019年   96篇
  2018年   101篇
  2017年   138篇
  2016年   150篇
  2015年   139篇
  2014年   262篇
  2013年   419篇
  2012年   296篇
  2011年   337篇
  2010年   267篇
  2009年   280篇
  2008年   286篇
  2007年   322篇
  2006年   308篇
  2005年   266篇
  2004年   203篇
  2003年   214篇
  2002年   202篇
  2001年   187篇
  2000年   122篇
  1999年   48篇
  1998年   20篇
  1997年   22篇
  1996年   18篇
  1995年   14篇
  1994年   11篇
  1993年   8篇
  1992年   10篇
  1991年   5篇
  1990年   7篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1983年   1篇
排序方式: 共有4989条查询结果,搜索用时 46 毫秒
81.
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   
82.
Louis Anthony Cox  Jr. 《Risk analysis》2012,32(11):1919-1934
Extreme and catastrophic events pose challenges for normative models of risk management decision making. They invite development of new methods and principles to complement existing normative decision and risk analysis. Because such events are rare, it is difficult to learn about them from experience. They can prompt both too little concern before the fact, and too much after. Emotionally charged and vivid outcomes promote probability neglect and distort risk perceptions. Aversion to acting on uncertain probabilities saps precautionary action; moral hazard distorts incentives to take care; imperfect learning and social adaptation (e.g., herd‐following, group‐think) complicate forecasting and coordination of individual behaviors and undermine prediction, preparation, and insurance of catastrophic events. Such difficulties raise substantial challenges for normative decision theories prescribing how catastrophe risks should be managed. This article summarizes challenges for catastrophic hazards with uncertain or unpredictable frequencies and severities, hard‐to‐envision and incompletely described decision alternatives and consequences, and individual responses that influence each other. Conceptual models and examples clarify where and why new methods are needed to complement traditional normative decision theories for individuals and groups. For example, prospective and retrospective preferences for risk management alternatives may conflict; procedures for combining individual beliefs or preferences can produce collective decisions that no one favors; and individual choices or behaviors in preparing for possible disasters may have no equilibrium. Recent ideas for building “disaster‐resilient” communities can complement traditional normative decision theories, helping to meet the practical need for better ways to manage risks of extreme and catastrophic events.  相似文献   
83.
卢道典  蔡喆 《城市观察》2012,(2):110-118
关于我国的城市规划管理权限一直存在"集中"与"放权"的讨论,并且城市规划管理体制也存在差异。通过对全国部分城市的规划管理体制进行梳理,从市、区(县、市)两级分权视角总结出我国城市规划管理体制中的"垂直型"、"半垂直型"和"非垂直型"三种典型模式,分别以南京、北京和上海为案例分析三种规划管理体制典型模式的主要特点和事权划分,并对其各自的优缺点进行比较,最后提出我国城市规划管理体制改革的若干建议,包括将规划决策权"上收"与实施管理重心"下移"、建立"市—区—镇(街)"三级规划管理机构体系、整合市区两级规划部门内部机构设置形成"大处室"和"大科室"以及完善城市规划委员会制度等。  相似文献   
84.
L'essor des chaînes d'approvisionnement mondiales (CAM) éloigne l'emploi de la demande, géographiquement et sectoriellement. Pour mieux comprendre le phénomène, les auteurs mesurent l'emploi lié aux CAM selon sa localisation et celle de la demande, en se fondant sur les données de la base WIOD et en complétant les estimations déjà présentées par le BIT. L'analyse porte sur la période 1995–2013 et sur 40 économies. Elle montre que la Chine, principale bénéficiaire de la demande liée aux CAM autrefois, contribue maintenant à l'alimenter, tout comme les relations de production entre économies émergentes. En outre, le poids des services liés à une demande manufacturière augmente.  相似文献   
85.
In electronics Fabs such as semiconductor Fabs and liquid crystal display (LCD) Fabs, which are capital-intensive, finite-capacity planning is critical to achieving full-capacity production and on-time production. However, existing finite-capacity planning methods do not adequately reflect the actual capacity profiles of an electronics Fab. In this paper, we propose a new Fab-level capacity-filtering procedure to generate finite-capacity plan: a backward capacity-filtering procedure for generating finite-capacity release plan. When developing the Fab-level filtering procedures, we use stage-level capacity-filtering algorithms as a key building block. In this study, we enhance the previous capacity-filtering algorithms proposed by one of the authors in order to facilitate the practical requirements of electronics Fabs. We apply the proposed capacity-filtering method to a modern LCD–TFT Fab in Korea. Performance analyses demonstrate that the proposed method is superior to existing methods.  相似文献   
86.
This paper discusses the extent to which topical planning issues of informality and illegality are incorporated into the educational curricula in Nigerian planning schools. Given the scale and enormity of informal and illegal settlements in Nigeria and other African cities, these issues should be emphasized in the education and training of planning professionals. Yet, few curricula in Nigerian planning schools, including the Nigerian Town Planners Registration Council’s professional curriculum, incorporate informal urban issues. The paper recommends an educational interventionist approach based on recognition of the potential of indigenous knowledge as a means of producing critical and reflective planning graduates who possess the competencies to deal with contemporary settlement challenges. It presents the institutional landscape for planning education and the processes of planning curricular reform and accreditation with a view to revitalizing planning education in Nigeria.  相似文献   
87.
高含水期陆相复杂断块层状油藏剩余油分布复杂,油藏模拟难度大。马11复杂断块油藏在油藏精细描述基础上,利用动静态综合分析研究与密网格大规模数值模拟研究相结合,提高了剩余油研究精度和可信度;在此基础上,针对油藏剩余油分布特点并结合当前经济技术条件,部署实施了以调整井、调剖、堵水、油水井大修为主的剩余油挖潜方案,油藏含水上升率大幅度下降、采油速度上升、采收率提高了。  相似文献   
88.
89.
We urgently need to put the concept of resilience into practice if we are to prepare our communities for climate change and exacerbated natural hazards. Yet, despite the extensive discussion surrounding community resilience, operationalizing the concept remains challenging. The dominant approaches for assessing resilience focus on either evaluating community characteristics or infrastructure functionality. While both remain useful, they have several limitations to their ability to provide actionable insight. More importantly, the current conceptualizations do not consider essential services or how access is impaired by hazards. We argue that people need access to services such as food, education, health care, and cultural amenities, in addition to water, power, sanitation, and communications, to get back some semblance of normal life. Providing equitable access to these types of services and quickly restoring that access following a disruption are paramount to community resilience. We propose a new conceptualization of community resilience that is based on access to essential services. This reframing of resilience facilitates a new measure of resilience that is spatially explicit and operational. Using two illustrative examples from the impacts of Hurricanes Florence and Michael, we demonstrate how decisionmakers and planners can use this framework to visualize the effect of a hazard and quantify resilience-enhancing interventions. This “equitable access to essentials” approach to community resilience integrates with spatial planning, and will enable communities not only to “bounce back” from a disruption, but to “bound forward” and improve the resilience and quality of life for all residents.  相似文献   
90.
Abstract

Purpose: This paper presents a combined multi-phase supplier selection model. The process repeatedly revisits the criteria and sourcing decision as the development process continues. This enables a structured adoption of product and production system innovation from strategic suppliers, where previously the literature purely focuses on product innovation or cost reduction. Design/methodology/approach: The authors adopted an embedded researcher style, inductive, qualitative case study of an industrial supply cluster comprising a focal automotive company and its interaction with three different strategic stamping suppliers. Findings: Our contribution is the multi-phased production and product innovation process. This is an advance from traditional supplier selection and also an extension of ideas of supplier-located product development as it includes production system development, and complements the literature on working with strategic suppliers. Specifically, we explicitly articulate the previously unreported issue of whether a supplier chosen for its innovation capabilities at the start of the new product development process will also be the most appropriate supplier during the production system development phase, when an ability to work collaboratively may be the most important attribute, or in the large-scale production phase when an ability to manufacture at low unit cost may be most important. Originality/value: The paper identifies a multi-phase approach to tendering within a fixed body of strategic suppliers which seeks to identify the optimum technological and process decisions as well as the traditional supplier sourcing choice. These areas have not been combined before and generate a valuable approach for firms to adopt as well as for researchers to extend our understanding of a highly complex process.  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