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   4944篇
  免费   396篇
  国内免费   95篇
财政金融   170篇
工业经济   211篇
计划管理   780篇
经济学   1325篇
综合类   612篇
运输经济   39篇
旅游经济   136篇
贸易经济   490篇
农业经济   1051篇
经济概况   621篇
  2024年   34篇
  2023年   156篇
  2022年   207篇
  2021年   209篇
  2020年   261篇
  2019年   198篇
  2018年   136篇
  2017年   195篇
  2016年   167篇
  2015年   199篇
  2014年   230篇
  2013年   351篇
  2012年   419篇
  2011年   453篇
  2010年   356篇
  2009年   302篇
  2008年   333篇
  2007年   345篇
  2006年   265篇
  2005年   163篇
  2004年   127篇
  2003年   83篇
  2002年   76篇
  2001年   67篇
  2000年   35篇
  1999年   16篇
  1998年   9篇
  1997年   11篇
  1996年   9篇
  1995年   5篇
  1994年   1篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   2篇
  1981年   2篇
排序方式: 共有5435条查询结果,搜索用时 15 毫秒
51.
ABSTRACT

Land market regulations are often justified by the assumption that activities of foreign and non-agricultural investors drive up prices in domestic land markets. However, empirical knowledge about the dynamics of agricultural land prices across borders is sparse. Using the German reunification as a natural experiment, we study the effect of the former inner German border on the dynamics of agricultural land prices in East and West Germany. We apply a land price diffusion model with an error correction specification to analyse spatial agricultural land markets. A novel feature of our model is its ability to distinguish price diffusion within states and across state borders. We provide evidence for a persistent border effect given that the fraction of spatially integrated counties is larger within states than across the former border. Moreover, we observe non-significant error correction terms for many counties along the former border. From a policy perspective, it is striking to realize that even 25 years after German reunification, pronounced land price differences persist. It is quite likely that price diffusion through existing borders within the EU would take even more time given language barriers, different institutional frameworks, and information asymmetries between domestic and foreign market participants.  相似文献   
52.
ABSTRACT

A comparative analysis of population dynamics worldwide contributes to profile distinctive demographic and economic trajectories of urban growth, discriminating processes of settlement concentration or dispersion under sequential cycles of urbanization. However, a wide-ranging characterization of urban cycles based on demographic dynamics worldwide is still missing. The present work is aimed at filling such a gap analysing long-term changes (1950–2030) in annual population growth rate of 1691 urban agglomerations with more than 300,000 inhabitants in 74 world countries. Results of this study indicate that metropolitan growth worldwide was associated with largely variable rates of population growth, highly positive before 2000 and progressively reducing over recent decades. Despite important differences at continental (and country) scale, demographic expansion of urban agglomerations showed two contrasting phases with a break point in the 1980s denoting a progressive reduction in spatial heterogeneity of population growth rates and a moderate slowdown in demographic dynamics. Intensity of urban expansion and spatial heterogeneity in population growth rates across metropolitan agglomerations evidences a trade-off between fast and slow demographic dynamics. These findings can be better understood to support theories of sequential city growth, making a suitable contribution to policy making, especially in countries where urban population is expanding more rapidly.  相似文献   
53.
This paper focuses on a new strand of research that uses stochastic approach for making spatial price comparisons. We propose a novel method to account for the presence of spatial dependencies in consumer prices and consequently in price indexes by imposing penalization conditions on the estimation of traditional CPD models leading to the spatially-penalized country-product-dummy (SP-CPD) model. The paper proposes an appropriate estimation strategy, which enables us to simultaneously estimate all the parameters in the model, including the smoothing parameter of the penalization term instead of determining it externally. In order to estimate spatial price indexes for areas lacking in price data, we suggest applying the kriging methodology to the price indexes obtained from the SP-CPD model. This new approach is applied to official Italian CPI data for constructing regional spatial price indexes for 2014. The results show that price levels are higher in the Northern-Central regions than in the South.  相似文献   
54.
依据城镇化发展过程中要素空间集聚理论,展开区域经济发展的空间经济结构研究。通过城市引力、克鲁格曼指数计算,比较分析城镇群内部城市吸引力和城市产业分布的差异性,通过人口与生产空间分布集中度指标和不一致系数的测算,分析了山西省城镇群空间要素集聚效应。研究表明,山西省的城镇群规划与要素空间集聚趋势整体一致,城市间产业分工体系基本形成,城镇群的要素集聚效应明显,但人口与生产分布仍存在不一致性。研究认为,山西省城镇群发展应该继续明确各城市的产业分工和特色,引导劳动力和资本要素的合理流动,实现人口与生产空间分布的一致。  相似文献   
55.
56.
The concept of the ‘polycentric urban region’ has been popularised both as a theoretical concept for understanding regional urban systems in an era of reduced transport and communication costs, and as a normative policy objective in its own right. This paper explores its relevance to the rapidly urbanising Cape Town city-region. First, empirical evidence for the emergence of polycentric regional development patterns was considered. Shifts in relative settlements sizes (morphological polycentrism) over the period 1991–2011 were examined using population data, and patterns of inter-settlement interactions (functional polycentrism) were explored by analysing commuting information. Contrary to expectations, trends toward polycentric development were found to be weak. Second, the paper considers the relevance and value of polycentric development thinking for regional economic and spatial planning policy, concluding that there are insufficient grounds for policy intervention aimed at encouraging polycentric regional development or countering the dominance of Cape Town in the region.  相似文献   
57.
我们已经进入了一个全新的大数据信息化时代,充满了更多的机遇与挑战。大数据及数字经济的出现极大程度地改变了传统技术及工作思维的方式。数字经济是继工业和农业之后的又一大经济形态,为社会的经济增长提供了新的动力。通过分析电网行业传统的科学技术及作业方式,论文简要阐述了基于大数据信息化发展下电网的影响,并认为信息化技术的发展对于数字经济有着至关重要的影响及重要性。最后论文讨论了数字经济发展存在的问题及方向。  相似文献   
58.
欧盟一直是我国最重要的贸易合作伙伴之一,荷兰则是我国在欧盟的前三大贸易伙伴之一,中荷贸易关系是中欧贸易关系中重要的一环,中欧班列的区域货源结构对中欧班列功能定位和发展规划意义重大。为明确中荷贸易背景下货源结构动态演化过程、特征及机制,在模糊C均值基础上,结合邻接矩阵对聚类分析结果进行修正,将各离散点货源数据进行合并聚类,剖析其时间和空间层面的演变及原因,探究货源结构时空演化趋势。结果表明:2014—2018年,中荷之间货源数量整体呈上升趋势,货源时空布局呈现空间集聚效应,表现为“由整到散”“西高东低”的演化态势。最后提出相关政策建议。  相似文献   
59.
研究目的:基于2007—2016年26省农业生产数据,测算"面源污染"和"碳排放"两类非期望产出下的农业环境效率,构建"耕地流转—利用规模—利用方式与利用强度—农业环境效率"的传导路径并进行计量检验。研究方法:超效率SBM模型,中介效应模型。研究结果:(1)耕地流转并未显著提高农业环境效率,但耕地利用规模对农业环境效率的影响呈倒U型;(2)耕地流转有助于扩大耕地利用规模,进而在样本中对农业环境效率呈现负向影响。与此同时,耕地流转对农业环境效率也存在正向的直接效应,正负效应基本抵消;(3)耕地利用规模主要通过改变化肥和机械投入强度进而负向影响农业环境效率。研究结论:农业环境效率受耕地流转、利用规模、利用方式和强度等多重因素影响,呈现明显的传导路径,因此,为了提高农业环境效率,在积极推行土地流转和规模化经营政策时,要注意结合地区农业生产力和地理环境,避免盲目扩大经营规模,同时鼓励规模经营主体引进农业绿色环保技术,注重农业生产资料的合理利用。  相似文献   
60.
[目的]深入分析江西省休闲农业示范点空间分布特征,进而可以提出促进区域休闲农业提升发展的对策建议。[方法]选取2010—2016年江西省国家级和省级休闲农业示范点作为数据,基于最邻近点指数、核密度估计法、不均衡指数和数量类型评价的方法,研究江西省休闲农业示范点的空间分布、类型构成与发展水平。[结果]江西休闲农业示范点空间上呈现聚集型分布特点,主要分布于中心城市、大型景区周边和交通干线沿线,以休闲农园、观光农园和生态农园等类型为主,存在空间分布不均衡、类型结构不合理等问题。[结论]以区域中心城市为中心,建设五大主题功能片区,优化多层级交通游线组织,加强城市、景区与农业资源丰富、生态环境优越区域的交通联系,并充分发挥休闲农业示范点的辐射带动作用,大力扶持培育休闲农业新业态,可以促进区域休闲农业的全面均衡发展。  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