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21.
我国畜禽养殖污染分区治理研究   总被引:3,自引:0,他引:3  
随着我国畜禽养殖业的迅猛发展,畜禽养殖污染已经成为我国重要的污染源,威胁着我国的水环境和土壤环境等。文章利用我国各省畜禽养殖污染统计年鉴数据,依据各区的畜禽养殖污染总量压力、土地负荷压力和地表水负荷压力以及经济负荷压力等级对我国主要畜禽养殖污染区域特征进行了分析。结果表明,黄淮海地区为H-H-H-H型畜禽养殖污染区,是我国畜禽养殖污染压力最大的地区;青藏高原区为L-L-L-L型畜禽养殖污染区,是我国畜禽养殖污染压力最小的地区;东北区和东南区畜禽养殖污染压力也较大,分别为H-M-M-H型畜禽养殖污染区和H-H-L-M型畜禽养殖污染区;蒙新高原区和黄土高原区畜禽养殖污染压力中等,分别为H-M-M-H型畜禽养殖污染区和H-H-L-M型畜禽养殖污染区;西南山地区畜禽养殖污染压力中等偏低,为M-M-L-L型畜禽养殖污染区。基于上述研究,该文对各区畜禽养殖污染的分区环境治理提出了若干针对性建议。  相似文献   
22.
We extend a continuous-time approximation approach to the analysis of escape dynamics in economic models with constant gain adaptive learning. This approach is based on the application of the results of continuous-time version of large deviations theory to the linear diffusion approximation of the original discrete-time dynamics under learning. We characterize escape dynamics by analytically deriving the most probable escape point and mean escape time. The approximation is tested on the Phelps problem of a government controlling inflation while adaptively learning a misspecified Phillips curve, studied previously by Sargent (1999) and Cho et al. (2002) (henceforth, CWS), among others. We compare our results with simulations extended to very low values of the constant gain and show that, for the lowest gains, our approach approximates simulations relatively well. We express reservations regarding the applicability of any approach based on large deviations theory to characterizing escape dynamics for economically plausible values of constant gain in the model of CWS when escapes are not rare. We show that for these values of the gain it is possible to derive first passage times for learning dynamics reduced to one dimension without resort to large deviations theory. This procedure delivers mean escape time results that fit the simulations closely. We explain inapplicability of large deviations theory by insufficient averaging near the point of self-confirming equilibrium for relatively large gains which makes escapes relatively frequent, suggest the changes which might help approaches based on the theory to work better in this gain interval, and describe a simple heuristic method for determining the range of constant gain values for which large deviations theory could be applicable.  相似文献   
23.
研究目的:分析研究影响耕地质量的主要障碍因素及其区域差异,明确不同区域耕地质量提升的主要途径和重点建设内容,以提高耕地质量提升工程建设的针对性和实效性。研究方法:相关分析法,主成分分析法,聚类分析法。研究结果:(1)土壤质地、有机质、全氮、速效磷、速效钾、灌溉率是影响耕地质量的主要因素,与粮食单产间均呈线性正相关关系,影响因素相互间也有影响,存在着显著的相关关系;(2)单产影响因素的重要性存在明显差异,其重要性序次为:灌溉率、速效磷、全氮、有机质、速效钾、土壤质地,重要性系数分别依次为0.188、0.179、0.173、0.167、0.156、0.136;(3)新郑市的耕地可划分为3种类型的整治区,不同类型区的耕地质量及其影响因素差异明显,丘岗地区的耕地质量最差,是农田整治的重点区,主要障碍因素是灌溉率低、土壤肥力差。研究结论:新郑市不同区域耕地质量提升的主要途径不同,丘岗地区和砂土平原区主要是提高农田灌溉率和培肥土壤,山前平原区主要是提高土壤磷肥肥力。  相似文献   
24.
Research summary> : W e take a microfoundational approach to understanding the origin of heterogeneity in firms' capacity to adapt to technological change. We develop a computational model of individual‐level learning in an organizational setting characterized by interdependence and ambiguity. The model leads to organizational outcomes with the canonical properties of routines: constancy, efficacy, and organizational memory. At the same time, the process generating these outcomes also produces heterogeneity in firms' adaptive capacity to different types of technological change. An implication is that exploration policy in the formative period of routine development can influence a firm's capacity to adapt to change in maturity. This points to a host of strategic trade‐offs, not only between performance and adaptive capacity, but also between adaptive capacities to different forms of change . Managerial summary : W hy are firms differentially effective at adapting to technological change? We argue that firms differ in the adaptive capacity of the routines that underlie their capabilities. These differences arise well before change occurs, and result because firms build routines that are differentially responsive to signals of performance decline associated with technological change. Thus, early managerial efforts to build superior productive efficiency must be complemented by efforts to build superior adaptive capacity. Our theory suggests that managers can prepare for technological change by implementing policies, in the formative period of organizational development, that promote individuals' exploration of novel actions. However, there are trade‐offs because preparation aimed at building adaptive capacity to one type of technological change may limit adaptive capacity to other types of change . Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
25.
This paper explores the theoretical underpinnings of collaboration and ecosystem management in order to identify the relationships and processes involved in implementing ecosystem management programs through cross‐sector collaboration. Ecosystem management requires a highly adaptive and resilient social–ecological governance approach, which addresses spatiality and temporality issues. In order to explore possible implementation issues with ecosystem management, propositions are developed dealing with adaptive governance, institutional isomorphism and collective action. The paper concludes with a discussion of the theoretic underpinnings involved in implementing ecosystem management through cross‐sector collaborations. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.  相似文献   
26.
Understanding the complex and adaptive nature of Pacific Island communities is a growing yet relatively unexplored area in the context of tourism development. Taking an ethnographic research approach, this study examines how over 40 years of tourism development have led to complex and multi-scale changes within an Indigenous Fijian village. The study establishes that tourism development has brought a range of ecological shifts that have, over time, spurred far-reaching changes within the embedded sociocultural constructs of the community. The development of the Naviti Resort, a water catchment dam, a causeway and a man-made island have created substantial changes in totemic associations, livelihood approaches, and traditional knowledge structures within Vatuolalai village. The emergence of internal adaptive cycles, and new behaviours, practices and values that redefine the cultural landscape will be discussed. This paper demonstrates the interconnectivity of nature, society and culture within Indigenous communal systems and asserts that ecological changes introduced in one part of a community stimulate complex, non-linear responses in other elements of the socio-ecological system of a Fijian village.  相似文献   
27.
Research Summary : How can strategic decision makers overcome inertia when dealing with change? In this article we argue that cognitive flexibility (i.e., the ability to match the type of cognitive processing with the type of problem at hand) enables decision makers to achieve significantly higher decision‐making performance. We show that superior decision‐making performance is associated with using semiautomatic Type 1 cognitive processes when faced with well‐structured problems, and more deliberative Type 2 processes when faced with ill‐structured problems. Our findings shed light on the individual‐level mechanism behind organizational adaptation and complement recent work on strategic inertia. In addition, our findings extend management studies that have stressed the relevance of cognitive flexibility for responding to the demands of increasingly open, flexible, and rapidly changing organizations. Managerial Summary : Humans are creatures of habits. We tend to prefer known courses of action over new ones. In many cases, habits are good. However, when things change in unpredictable ways, the past may not be good guidance for the future. We argue that “cognitive flexibility”—the ability of understanding when to rely on habits vs. when to explore new courses of action—enables managers to switch from a “fast” decision mode, based on habits, to a “slow,” more deliberate decision mode that facilitates the exploration of new courses of action. Managers high in cognitive flexibility reflect on the situation at hand, recognize and value diversity in viewpoints, and integrate such diversity in their own decision processes. By valuing diversity, they are more likely to overcome inertia.  相似文献   
28.
This paper advances understanding of the complex and adaptive nature of indigenous Fijian communities involved in tourism. It examines how tourism-related development has set the people of one Fijian village along two separate development pathways, and explores how preferential access to tourism benefits has created disparities within the community. Complex Adaptive Systems theory and Social Capital theory are used to conceptualise how over 40 years of tourism involvement has influenced development within an indigenous Fijian community. The findings argue that indigenous Fijian communities are non-homogeneous entities, which are constantly in transition, responding and adapting integratively to both internal and external changes over time. The findings show that the emergence of new behaviours and ways of life has led to the collapse of the pre-existing systems of social capital. As a response, community members retreated and regrouped, strengthening internal bonds and social capital in their smaller social units, leading to both dependency and opportunity-seeking behaviours among participants. Ultimately, the paper asserts that money alone does not lead to development, but rather tourism and access to a variety of capital do.  相似文献   
29.
金融创新产品风险的监管不到位是2007年美国次贷危机及2008年全球金融危机爆发的主要原因之一。在对MBS、CDO与CDS等创新产品风险及监管进行分析基础上创建的金融创新产品风险适应性监管机制框架包括风险的识别、风险的层级报告、风险的预警、风险的监管介入、风险的处理和金融危机与经济危机的预防六个部分。  相似文献   
30.
企业并购后的品牌整合是在复杂多变的环境中进行的,品牌整合系统是一个复杂适应系统.CAS理论为企业并购后的品牌整合提供了新视角和方法论的指导。  相似文献   
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