全文获取类型
收费全文 | 1367篇 |
免费 | 42篇 |
国内免费 | 2篇 |
专业分类
财政金融 | 87篇 |
工业经济 | 41篇 |
计划管理 | 337篇 |
经济学 | 385篇 |
综合类 | 34篇 |
运输经济 | 60篇 |
旅游经济 | 33篇 |
贸易经济 | 87篇 |
农业经济 | 256篇 |
经济概况 | 91篇 |
出版年
2024年 | 2篇 |
2023年 | 25篇 |
2022年 | 52篇 |
2021年 | 58篇 |
2020年 | 114篇 |
2019年 | 69篇 |
2018年 | 39篇 |
2017年 | 83篇 |
2016年 | 76篇 |
2015年 | 56篇 |
2014年 | 91篇 |
2013年 | 122篇 |
2012年 | 79篇 |
2011年 | 124篇 |
2010年 | 55篇 |
2009年 | 76篇 |
2008年 | 78篇 |
2007年 | 51篇 |
2006年 | 42篇 |
2005年 | 22篇 |
2004年 | 27篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有1411条查询结果,搜索用时 46 毫秒
31.
本文借鉴近年来兴起的主流空间统计分析方法,对1985-2007年期间我国29个省市区实际利用外资的空间自相关性进行了研究,并测量了空间集聚效应和空间辐射效应。研究结果表明:自1989年以来,我国29个省市区实际利用外资存在空间自相关性;从空间集聚效应来看,空间集聚逐渐从珠三角、长三角向环渤海地区扩散,从东部沿海地区向中部地区扩散,与我国对外开放的格局基本保持一致;从空间辐射效应来看,具有正向辐射效应的高高集聚型省市区日益集聚在东部和中部地区,具有负向辐射效应的低低集聚型省市区日益集聚在西部地区。 相似文献
32.
为应对后疫情时代全球电子信息产业加剧的“比较优势陷阱”,中国亟需通过国内价值链省域比较优势的互补协同提升整体国际竞争力。在价值链产品内,基于垂直专业化分工框架,兼顾增值能力与劳动生产率两个维度,使用非竞争型投入占用产出模型,设计一个评测国家内部区域电子信息产业真实比较优势的新指标。结果表明,东部沿海省域比较优势强度与广度最为显著,内陆省域比较优势集中于上游能源型部门;制造业部门比较优势凸显,服务业部门比较优势相对薄弱;比较优势高省域集中度与低省域集中度的产业部门中,均存在整体比较优势强弱差异,其中,高省域集中度产业部门比较优势强度更高。 相似文献
33.
创造性地对空间计量经济学中的空间相关性思想进行嫁接利用,在思路方法上进行开拓,构建反映同行业内企业间相互联系与各行业间相互关联的空间权重矩阵,建立空间杜宾模型,并以制造业为例,对ODI逆向技术溢出效应的行业内和行业间路径进行实证检验。对行业内路径的检验表明,企业全要素生产率受到同行业内其它企业ODI活动的影响,行业内企业通过ODI促进自身技术进步之后,又通过企业间各种竞争合作关系促进同行业其它企业生产率提高,行业内路径由此得以验证。对行业间路径的检验表明,各行业通过ODI促进本行业技术进步之后,又通过行业间前向与后向产业关联,对其它关联行业的技术进步和生产率提高起到促进作用,且产业完全关联下的促进作用大于直接关联,由此行业间路径得以验证。 相似文献
34.
Natural vegetation enhances the value of agricultural landscapes for people and wildlife. However, the role of anthropogenic versus topographic factors in driving the extent of natural vegetation cover within agricultural lands at large spatial scales remains unexplored. I assessed the influence of anthropogenic and topographic variables on the extent of agricultural mosaics with high natural vegetation cover in the country of Turkey where a large extent of natural and semi-natural vegetation is maintained by traditional agriculture. GIS layers depicting human land use, elevation, slope, roads and population data were obtained and summarized at two spatial scales, within provinces and for 100 km2 grid cells covering the country’s entire agricultural land area. Average farm size was also obtained at province level. Hierarchical Partitioning was conducted to determine the independent effect of anthropogenic and topographic variables on the variation in agriculture with high natural vegetation. Slope had the largest independent effect on the variation in the proportion of agricultural mosaic with high natural vegetation cover. The extent of agricultural and settlement area also explained much of the variation in natural vegetation across both grid cells and provinces. The proportion of natural vegetation increased as human population and road density decreased across grid cells and as average farm size decreased across provinces. These results suggest that while topography is the primary driver of natural vegetation cover within agricultural mosaics in Turkey, the pressures associated with urban development and agricultural industrialization may also influence the cultural and wildlife value of agricultural landscapes. 相似文献
35.
Differences in the internal composite structure during urban built-up land sprawl (UBLS) will generate different effects, and thus, a city’s spatial structure has important bearings on urban sustainability. This study investigates the spatial and temporal characteristics of the internal structure and allocation relationship of UBLS using multivariate spatial correlation and the Weaver-Tomas composite coefficient based on site data of granted built-up land parcels. Moreover, the composite structure evolution process of UBLS and its driving mechanism are examined in this study. The results reveal that the amount structure of the three types of UBLS (i.e. industrial land sprawl, residential land sprawl and commercial land sprawl) tended to be balanced during the study period. Following the transformation and upgrade of the urban industry structure, the overall composite structure of UBLS ranged from single residential land-use structure (Res.) to industrial-residential land-use structure (Ind.-Res.) In the early period of land marketization, the marketization land granting mechanism caused low spatial correlation between the various types of UBLS and a single composite structure, i.e. Res., single commercial land-use structure (Com.), and residential-commercial land-use structure (Res.-Com.). Subsequently, a dual-driving force including the market economy and government interventions caused a relatively high degree of spatial correlation and a multiple composite structure, i.e. Ind.-Res. and industrial-residential-commercial land-use structure (Ind.-Res.-Com.). However, the evolution characteristics of the composite structure in various regions illustrate some problems, such as the spatial isomorphism phenomenon of the composite structure and the dislocation of urban built-up land allocation. The urban internal built-up land spatial layout pattern is the embodiment of two dominant driving forces, the market and the government, interacting with each other according to natural and socioeconomic conditions. Therefore, we suggest that it is necessary to reform the future urban built-up land granting mechanism based on market guidance, and the composite structure of UBLS should be adjusted according to the regional function. The government should reinforce the macro-control of land-use planning for the dispersed granted land parcels so as to optimize the urban land-use structure. 相似文献
36.
In recent years, what has become known as collaborative consumption has undergone rapid expansion through peer-to-peer (P2P) platforms. In the field of tourism, a particularly notable example is that of Airbnb. This article analyses the spatial patterns of Airbnb in Barcelona and compares them with hotels and sightseeing spots. New sources of data, such as Airbnb listings and geolocated photographs are used. Analysis of bivariate spatial autocorrelation reveals a close spatial relationship between Airbnb and hotels, with a marked centre-periphery pattern, although Airbnb predominates around the city's main hotel axis and hotels predominate in some peripheral areas of the city. Another interesting finding is that Airbnb capitalises more on the advantages of proximity to the city's main tourist attractions than does the hotel sector. Multiple regression analysis shows that the factors explaining location are also different for hotels and Airbnb. Finally, it was possible to detect those parts of the city that have seen the greatest increase in pressure from tourism related to Airbnb's recent expansion. 相似文献
37.
In this paper we investigate the optimal harvesting of a renewable natural resource. While in most standard approaches the resource is located at a single point, we allow the resource to be distributed spatially. Consequently, an agent who exploits the resource has to travel from one location to another. For a fixed planning horizon, we investigate the speed and the path of harvesting chosen by the agent. We show that the agent adjusts this speed so as to visit each location only once, even in the absence of travelling cost. Since the agent does not return to any location for a second harvest, it is optimal to fully deplete the resource upon arrival. A similar type of bang–bang solution results when we drop the assumption of a constant harvesting rate: allowing for a variable harvesting rate, the agent chooses to fully exploit the resource either in the last or in the first travelling period. A society interested in conserving some of the resource thus has to take measures to limit the exploitative behaviour of the agent. 相似文献
38.
In this paper we propose ridge regression estimators for probit models since the commonly applied maximum likelihood (ML) method is sensitive to multicollinearity. An extensive Monte Carlo study is conducted where the performance of the ML method and the probit ridge regression (PRR) is investigated when the data are collinear. In the simulation study we evaluate a number of methods of estimating the ridge parameter k that have recently been developed for use in linear regression analysis. The results from the simulation study show that there is at least one group of the estimators of k that regularly has a lower mean squared error than the ML method for all different situations that have been evaluated. Finally, we show the benefit of the new method using the classical Dehejia and Wahba dataset which is based on a labour market experiment. 相似文献
39.
One of the main issues with the concept of ecosystem services is its absence on the ground in concrete operational decision-making contexts; that is, an implementation gap. In this study, we investigated if this gap could be overcome through the use of open-source data and free tools, and the adoption of a short-term participatory process. We tested these methods in the context of a project in the urban metropolitan area of Bordeaux (Communauté urbaine de Bordeaux: CUB) in France. The ecosystem services were defined using a participatory approach involving local stakeholders, and then selected scenarios were simulated to test the impact of various development or conservation plans. The study addressed three main questions: (1) Is it possible to adopt a simple methodological approach that overcomes the implementation gap through the development of a user-friendly and inclusive method? (2) What is the added value of a participatory approach? (3) With regards to four scenarios in this territory, what are the ES trends in the selected biophysical and monetary indicators, and will knowledge of these trends help planners to shape a sustainable trajectory for the territory? 相似文献
40.
Megaregion has emerged as a new dimension of global urbanization. A megaregion approach based on polycentric strategy is deemed to enhance regional economic competitiveness. Numerous studies have highlighted the economic benefits, celebrated the spill-over effects, and outlined the creative potentials of contemporary megaregion policies in different nations worldwide. However, further policy instruments require the knowledge about the achievement and failure of megaregion policies that seek for spatial, economic, social, and environmental efficiency and sustainability. This paper introduces China’s megaregion policy and proposes an analytical framework for performance evaluation from four principle domains (rational urban growth, economic development, social equity, environmental protection) at three levels (internal collaboration, integral development, and overall development). Using a case of the Megaregion around Hangzhou Bay (MAHB), we find very limited success of China’s megaregion policy. In particular, the megaregion policy only accomplishes the economic goal, and fails to achieve the goals of rational urban growth, environmental protection, and social equity. A series of mechanism based regressions are established and show that the implementation duration of megaregion policy: (1) associates positively with the economic growth; (2) relates negatively to social equity and urban rational growth; and (3) has no significant relationship with improved environmental quality. Institutional fragmentation, no unified spatial planning, and inadequate legislation at megaregional level are the underlying causes of the expected performances within the policy context of governance itself. We finally propose some possible solutions and discuss the implications for spatial polycentric governance. The demonstrated methodological framework can be applicable to other megaregions around the world. This paper is thus believed to provide some new insights for land use policy. 相似文献