全文获取类型
收费全文 | 34119篇 |
免费 | 155篇 |
国内免费 | 3篇 |
专业分类
财政金融 | 5654篇 |
工业经济 | 2071篇 |
计划管理 | 5758篇 |
经济学 | 7487篇 |
综合类 | 756篇 |
运输经济 | 143篇 |
旅游经济 | 366篇 |
贸易经济 | 7480篇 |
农业经济 | 936篇 |
经济概况 | 2982篇 |
信息产业经济 | 45篇 |
邮电经济 | 599篇 |
出版年
2024年 | 78篇 |
2021年 | 132篇 |
2020年 | 233篇 |
2019年 | 341篇 |
2018年 | 2610篇 |
2017年 | 2399篇 |
2016年 | 1579篇 |
2015年 | 379篇 |
2014年 | 550篇 |
2013年 | 1780篇 |
2012年 | 925篇 |
2011年 | 2424篇 |
2010年 | 2241篇 |
2009年 | 2030篇 |
2008年 | 2041篇 |
2007年 | 2325篇 |
2006年 | 519篇 |
2005年 | 816篇 |
2004年 | 812篇 |
2003年 | 921篇 |
2002年 | 612篇 |
2001年 | 407篇 |
2000年 | 381篇 |
1999年 | 314篇 |
1998年 | 345篇 |
1997年 | 337篇 |
1996年 | 339篇 |
1995年 | 290篇 |
1994年 | 292篇 |
1993年 | 307篇 |
1992年 | 299篇 |
1991年 | 277篇 |
1990年 | 257篇 |
1989年 | 232篇 |
1988年 | 177篇 |
1987年 | 203篇 |
1986年 | 228篇 |
1985年 | 318篇 |
1984年 | 320篇 |
1983年 | 316篇 |
1982年 | 280篇 |
1981年 | 270篇 |
1980年 | 222篇 |
1979年 | 240篇 |
1978年 | 175篇 |
1977年 | 190篇 |
1976年 | 158篇 |
1975年 | 129篇 |
1974年 | 119篇 |
1973年 | 108篇 |
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
991.
E.L. Banks R.G. Mauldon 《The Australian journal of agricultural and resource economics》1966,10(1):1-13
Applying econometric analysis to a model recently used by Parish, this article examines the short-run implications for consumers and producers of the pricing decisions of the Western Australian Egg Board over the period 1953-54 to 1962-63. 相似文献
992.
Dynamics in the global food system, coupled with rapid advance in agricultural biotechnology, have resulted in additional demands for capturing information and sharing information vertically within the supply chain. Food safety and quality characteristics are a cornerstone of this information demand. Events such as foot-and-mouth disease (FMD) and bovine spongiform encephalopathy (BSE), genetic engineering and animal welfare concerns have laid the foundation for additional information need.
Managers of private firms within the food supply chain must decide how to respond to the situation. A crucial component of the problem is what and how to provide information to downstream customers as well as stipulate what and how information is received from upstream suppliers. Alternative signaling mechanisms abound. The choice among these alternative signals, or combination of alternatives, has both short- and long-run implications for the reputation of the firm, its products or services, and the efficiency with which it conducts its business. The signaling problem in the supply chain is bidirectional and has three critical dimensions: information asymmetry, incentive asymmetry, and arduous measurability. From a broad perspective, the choice set for signaling includes: strategies that rely on third-party protocols and procedures; differentiation through branding and reputation; indemnification strategies such as insurance, warranties, and bonding; and coordination strategies such as strategic alliances and vertical integration (intemalization). Each mechanism for signaling differentially influences the three dimensions of the signaling problem. No globally optimal strategy solution exists. Differentiation through branding and reputation mitigate the signaling problem relatively well compared with the other alternatives. 相似文献
Managers of private firms within the food supply chain must decide how to respond to the situation. A crucial component of the problem is what and how to provide information to downstream customers as well as stipulate what and how information is received from upstream suppliers. Alternative signaling mechanisms abound. The choice among these alternative signals, or combination of alternatives, has both short- and long-run implications for the reputation of the firm, its products or services, and the efficiency with which it conducts its business. The signaling problem in the supply chain is bidirectional and has three critical dimensions: information asymmetry, incentive asymmetry, and arduous measurability. From a broad perspective, the choice set for signaling includes: strategies that rely on third-party protocols and procedures; differentiation through branding and reputation; indemnification strategies such as insurance, warranties, and bonding; and coordination strategies such as strategic alliances and vertical integration (intemalization). Each mechanism for signaling differentially influences the three dimensions of the signaling problem. No globally optimal strategy solution exists. Differentiation through branding and reputation mitigate the signaling problem relatively well compared with the other alternatives. 相似文献
993.
Olive oil production and soil conservation in southern Spain, in relation to EU subsidy policies 总被引:2,自引:0,他引:2
The European Union spent about two billion ECU per year on subsidies for the olive oil sector, of which Spain received about 35%. For the rainfed areas in southern Spain the olive oil sector is crucial, and so are these subsidies. The European Commission has formulated two options to change the subsidy system, but these do not take the production systems and environmental aspects into account. Many olive plantations are affected by soil erosion. This paper analyses the olive tree production systems in southern Spain, the subsidy systems and the soil erosion problems. It then raises the question whether the subsidies could not be provided in a different way, in order to make olive tree cultivation more sustainable by reducing soil erosion and flood hazard. 相似文献
994.
This paper estimates technical efficiency (TE) measures using four alternative production frontier models, and evaluates the sensitivity of the results to the choice of methodology. The Cobb-Douglas functional form along with data for 1982 and 1983 from 404 dairy farms located throughout six northeastern states in the US are used in the estimation. A general conclusion is that, broadly speaking, frontier function models are neutrally upwardly scaled versions of the OLS or average model. A second conclusion is that different models yield markedly different efficiency levels across firms. However, the correlation between the indexes from the various methods is high, which implies that the ordinal ranking of firms according to their measured level of technical efficiency appears to be independent of the method used for a given year. By comparison, the correlation between efficiency indexes for the same method across time, although positive, is much lower than the previous set of correlations. Correlation analysis of efficiency versus farm size and of efficiency versus returns over variable costs, based on the alternative models, yielded consistent results. 相似文献
995.
Jayson L. Lusk W. Bruce Traill Lisa O. House Carlotta Valli Sara R. Jaeger Melissa Moore Bert Morrow 《Journal of Agricultural Economics》2006,57(1):1-21
The United States (US) exports more than US$6 billion in agricultural commodities to the European Union(EU) each year, but one issue carries the potential to diminish this trade: use of biotechnology in food production. The EU has adopted more stringent policies towards biotechnology than the US. Understanding differences in European and American policies towards genetically modified (GM) foods requires a greater understanding of consumers’ attitudes and preferences. This paper reports results from the first large‐scale, cross‐Atlantic study to analyse consumer demand for genetically modified food in a non‐hypothetical market environment. We strongly reject the frequent if convenient assumption in trade theory that consumer preferences are identical across countries: the median level of compensation demanded by English and French consumers to consume a GM food is found to be more than twice that in any of the US locations. Results have important implications for trade theory, which typically focuses on differences in specialization, comparative advantage and factor endowments across countries, and for on‐going trade disputes at the World Trade Organization. 相似文献
996.
Alternative land management practices, including agroforestry, help to maintain levels of soil organic matter (SOM) and can facilitate soil carbon (C) sequestration for mitigating atmospheric CO2 emissions. This study quantified C inputs and determined the changes of the soil C pool in a 19-year-old Gliricidia sepium alley cropping system, studied at two fertiliser levels (tree prunings only [? N], and tree prunings plus chicken manure [+ N]), and was compared to a sole crop system. Carbon input from tree prunings ranged from 455 to 457 g C m? 2 y? 1, whereas C inputs from crop residues were similar between alley- and sole crops ranging from 121 to 159 g C m? 2y? 1. The soil organic C (SOC) pool in the alley crop was 16–23% higher than the sole crop. In the 19th year of alley farming, SOC was significantly higher (p < 0.05) in the alley crop (3.2%) compared to the sole crop (2.4%), and was also greater compared to that at the time of establishment of the agroforestry system (2.8%). Gross SOC turnover to a 20-cm depth ranged from 12 to 14 years in the + N and ?N alley crops compared to 49 and 50 years in the + N and ?N treatments for the sole crops. Residue stabilisation efficiency in the alley crops was 39% and 55% in + N and ?N treatments respectively. 相似文献
997.
Is There Persistence in the Impact of Emergency Food Aid? Evidence on Consumption, Food Security, and Assets in Rural Ethiopia 总被引:1,自引:0,他引:1
We identify the impact of emergency food aid programs after the 2002 drought in rural Ethiopia on future welfare. Based on a difference-in-differences matching estimator, participation in food-for-work increases growth in total consumption and food consumption eighteen months after the drought. Separately, receiving free food raises growth in food consumption, but, surprisingly, negatively impacts food security. Food-for-work benefited households in the middle and upper tail of the consumption distribution, while the better-targeted free food program benefited the poorest. Evidence suggests these impacts demonstrate accumulated and persistent effects of food aid received in the first twelve months after the drought. 相似文献
998.
Why Farmers Quit: A County-Level Analysis 总被引:1,自引:0,他引:1
Stephan J. Goetz & David L. Debertin 《American journal of agricultural economics》2001,83(4):1010-1023
We identify the effects of alternative explanatory variables on the propensity of U.S. farmers to cease farming, with a particular emphasis on understanding the roles of off-farm employment and federal farm program payments. Conventional ordinary least squares analysis using all counties suggests that off-farm employment has no statistical effect on the (net) number of farmers quitting between 1987 and 1997, ceteris paribus . A more refined analysis, which separates counties losing farmers from those that gained farmers, reveals subtle and less clear-cut effects of off-farm employment (and federal program payments) on farm exits. 相似文献
999.
Jayson L. Lusk Jason Brown Tyler Mark Idlir Proseku Rachel Thompson Jody Welsh 《Review of Agricultural Economics》2006,28(2):284-292
Recent work by agricultural economists has failed to adequately identify why consumers desire country-of-origin labeling, a key piece of information needed to determine whether a market-failure exists. This paper brings to the attention of agricultural economists a sizable body of literature on country-of-origin effects from the marketing and business disciplines. Based on this literature, we draw a distinction between several consumer motivations for origin labels and we identify which of these is cause for public policy. We propose several research questions that require answers if the consequences of country-of-origin labeling policy are to be fully understood. 相似文献
1000.