全文获取类型
收费全文 | 14481篇 |
免费 | 939篇 |
国内免费 | 241篇 |
专业分类
财政金融 | 1115篇 |
工业经济 | 768篇 |
计划管理 | 2683篇 |
经济学 | 2809篇 |
综合类 | 1762篇 |
运输经济 | 100篇 |
旅游经济 | 87篇 |
贸易经济 | 1764篇 |
农业经济 | 2720篇 |
经济概况 | 1853篇 |
出版年
2024年 | 44篇 |
2023年 | 363篇 |
2022年 | 336篇 |
2021年 | 480篇 |
2020年 | 554篇 |
2019年 | 383篇 |
2018年 | 384篇 |
2017年 | 489篇 |
2016年 | 520篇 |
2015年 | 495篇 |
2014年 | 1002篇 |
2013年 | 1176篇 |
2012年 | 1175篇 |
2011年 | 1320篇 |
2010年 | 975篇 |
2009年 | 900篇 |
2008年 | 1019篇 |
2007年 | 847篇 |
2006年 | 804篇 |
2005年 | 584篇 |
2004年 | 398篇 |
2003年 | 329篇 |
2002年 | 242篇 |
2001年 | 232篇 |
2000年 | 152篇 |
1999年 | 104篇 |
1998年 | 85篇 |
1997年 | 52篇 |
1996年 | 52篇 |
1995年 | 28篇 |
1994年 | 29篇 |
1993年 | 27篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Farmers in the Vietnamese Mekong Delta face a wide range of climate-related and hydrological factors which threaten rice production. Smallholder farmers must adapt to climate change to sustain rice production as their central and most important livelihood activity. A sample was stratified across agro-ecological areas in the Delta affected by flooding, alluvial soils, acid sulphate soils, and saline water intrusion and by derived farmer typologies. A rural livelihoods approach was used in focus group discussions and in-depth interviews to identify and enumerate enabling and constraining adaptation factors. Smallholders experienced diverse natural hazards such as floods, abnormal rains, high temperatures, water scarcity, and salinity intrusion specific to the agro-ecological areas. Adaptation was constrained by labour shortages, water quality, topography, access to combine harvesters, transportation infrastructure, dryers and household savings. Adaptation was enabled by farming techniques and experience, cooperative groups, water quantity, access to information, and ability to purchase agro-chemicals through credit. Small farmers (< 1?ha) were more constrained than large farmers (> 1?ha) who had an expanded livelihood asset base. A range of policy implications are discussed, but adaptation is not just about technological fixes but requires overall improvements in a range of human, social and financial components. 相似文献
22.
Assessing cost‐effectiveness when environmental benefits are bundled: agricultural water management in Great Barrier Reef catchments 下载免费PDF全文
John Rolfe Jill Windle Kevin McCosker Adam Northey 《The Australian journal of agricultural and resource economics》2018,62(3):373-393
Using economic analysis to prioritise improvements in environmental conditions is particularly difficult when multiple benefits are involved. This includes ‘bundling’ issues in agricultural pollution management, where a change in management action or farming systems generates multiple improvements, such as reductions in more than one pollutant. In this study, we conceptualise and compare two different approaches to analysing cost‐effectiveness when varying bundles of benefits are generated for a single project investment. Each approach requires data to be transformed in some way to allow the analysis to proceed. The index approach requires the transformation on the benefits side so that the effects of multiple pollutant changes can be combined into a measure for each project which can then be compared to costs. By comparison, the disaggregation approach requires the transformation on the costs side where costs for each project have to be apportioned across the different pollutants involved. The paper provides novel insights with an application to agricultural water quality improvements into the Great Barrier Reef in Australia, demonstrating that while both approaches are effective in prioritising projects by cost‐effectiveness, the disaggregation approach provides more insightful results and values that may be relevant for use as upper value guidelines in future project selection. 相似文献
23.
赵连明 《中国农业资源与区划》2018,39(7):92-98
[目的]通过分析重庆市农业科技资源配置效率及影响因素,以期对重庆市的农业科技资源的合理配置提出参考建议。[方法]构建评价指标体系,以农业科技创新资源配置环境、农业科技资源经费投入、农业科技人才储备和农业科技创新成果4个方面构成综合层,向下分16个具体指标,运用层次分析法和模糊评判综合评价重庆市农业科技资源配置效率及影响因素。[结果]重庆市农业科技创新资源的配置效率综合得分为81.08,为2级水平,其中农业科技人员流失比例较大,投入产出效率较低成为主要制约因素。[结论]重庆市农业科技创新资源的配置效率处于中等水平,合理配置农业科技人员和经费投入以及提高资源配置环境是提高重庆市农业科技协同创新资源的配置效率的关键;农业科技资金投入浪费严重和农业科技活动成果的转化率较低、农业科技人才结构和农业科技创新资源配置方式的不合理以及农业科技市场机制尚不完善是影响农业科技资源配置效率的主要因素。 相似文献
24.
《Socio》2019
This article deals with the modelling of the static and dynamic technical efficiency under conditions of municipal libraries of municipalities with 1000–5000 inhabitants. The aim of this article is to determine the level of the technical efficiency and the factors that influence the results of modelling of the static and dynamic technical efficiency of 34 selected municipal libraries for the years of 2011 and 2015. The first model tests the technical efficiency of conventional services of public libraries. The second model tests the technical efficiency of municipal libraries’ operation. The third model tests the technical efficiency of the key revenues and expenditures. The results in the static models estimate the average technical efficiency of municipal libraries in the interval (0.691–0.759) for the input-oriented models, and in the interval (1.413–2.005) for the output-oriented models. In the dynamic models, the majority of municipal libraries in 2015 showed lower technical efficiency and productivity in comparison with the year of 2011. The factors influencing the level of efficiency and its course include the inputs and the outputs, and their combinations within individual models. 相似文献
25.
Three decades of productivity change in French beef production: a Färe‐Primont index decomposition 下载免费PDF全文
K Hervé Dakpo Philippe Jeanneaux Laure Latruffe Claire Mosnier Patrick Veysset 《The Australian journal of agricultural and resource economics》2018,62(3):352-372
The Färe‐Primont index is used to evaluate total factor productivity (TFP) change and its components for a sample of French suckler cow farms in grassland areas in 1985–2014. The results reveal an increase in TFP of 6.6 per cent over the whole observation period, with technological progress being the major source of productivity growth. Meanwhile, efficiency decreased. Farms experienced great technological progress from 1991 to 2000. From a methodological point of view, the comparison with results obtained with Malmquist indexes shows similar trends but different magnitudes, with the Malmquist index overestimating the TFP and technological changes compared to the Färe‐Primont index. In addition, the use of a sequential approach that restricts technological change to being positive or null allows for the precise calculation of technology changes, disregarding the effects of external conditions that are captured in efficiency changes. Finally, the estimation of full dimensional efficient facets (FDEFs) that guarantees the positivity of all shadow prices used to assess the mix efficiency component of TFP change is promising. 相似文献
26.
对建筑企业进行环境行为效率评价是促进我国建筑行业健康可持续发展的重要手段。根据建筑行业特点及我国现有的企业环境信用标准,构建了建筑企业环境行为评价的投入产出指标体系,将改进的数据包络分析方法模型运用到企业环境行为效率评价领域,解决了现有企业评价研究主观性突出的问题,得出建筑企业评价分析方法。在此基础上对某代表性建筑企业2010—2017年环境行为数据进行了评价分析。分析结果表明该企业环境行为总体效率良好,但鉴于出现了奇数年和偶数年的效率波动情况,仍需提高环境行为效率。 相似文献
27.
This study examines why most derivatives markets that settle on the day following expiration choose the opening rather than the closing price as the final settlement price (FSP), whereas most markets that settle on the expiration day select an average rather than a single price as the FSP. Four exogenous changes in the Taiwan Futures Exchange settlement procedures provide an experimental basis for studying the settlement procedures’ impact on underlying assets. Greatest market efficiency is observed when the FSP is determined by a single rather than an average price and hypothesize that manipulation is prevented at the expense of market quality. 相似文献
28.
29.
Hanspeter Wieland Stefan Giljum Martin Bruckner Anne Owen Richard Wood 《Economic Systems Research》2018,30(1):61-84
Recent empirical assessments revealed that footprint indicators calculated with various multi-regional input–output (MRIO) databases deliver deviating results. In this paper, we propose a new method, called structural production layer decomposition (SPLD), which complements existing structural decomposition approaches. SPLD enables differentiating between effects stemming from specific parts in the technology matrix, e.g. trade blocks vs. domestic blocks, while still allowing to link the various effects to the total region footprint. Using the carbon footprint of the EU-28 in 2011 as an example, we analyse the differences between EXIOBASE, Eora, GTAP and WIOD. Identical environmental data are used across all MRIO databases. In all model comparisons, variations in domestic blocks have a more significant impact on the carbon footprint than variations in trade blocks. The results provide a wealth of information for MRIO developers and are relevant for policy makers designing climate policy measures targeted to specific stages along product supply chains. 相似文献
30.
针对M企业A生产线在制品积压、交付周期长等问题,通过现状价值流图分析其原因,提出在考虑改善效益大于投入成本的条件下,选择合适的自动化水平,以克服物料供应不及时、工艺特性等制约因素。从工艺流程、布局、工装等方面进行改善并绘制未来价值流图,创建生产线连续流。生产线连续流创建后,生产周期缩短了13天、搬运距离减少41m、车间面积节省约168m2、作业人数减少6人,为企业降本增效打下了坚实基础。 相似文献