全文获取类型
收费全文 | 8441篇 |
免费 | 238篇 |
专业分类
财政金融 | 1608篇 |
工业经济 | 765篇 |
计划管理 | 1504篇 |
经济学 | 1730篇 |
综合类 | 92篇 |
运输经济 | 54篇 |
旅游经济 | 153篇 |
贸易经济 | 1468篇 |
农业经济 | 415篇 |
经济概况 | 885篇 |
信息产业经济 | 1篇 |
邮电经济 | 4篇 |
出版年
2021年 | 60篇 |
2020年 | 99篇 |
2019年 | 144篇 |
2018年 | 174篇 |
2017年 | 178篇 |
2016年 | 200篇 |
2015年 | 104篇 |
2014年 | 192篇 |
2013年 | 893篇 |
2012年 | 269篇 |
2011年 | 319篇 |
2010年 | 256篇 |
2009年 | 287篇 |
2008年 | 256篇 |
2007年 | 241篇 |
2006年 | 192篇 |
2005年 | 217篇 |
2004年 | 194篇 |
2003年 | 195篇 |
2002年 | 181篇 |
2001年 | 195篇 |
2000年 | 189篇 |
1999年 | 172篇 |
1998年 | 152篇 |
1997年 | 149篇 |
1996年 | 134篇 |
1995年 | 136篇 |
1994年 | 116篇 |
1993年 | 132篇 |
1992年 | 134篇 |
1991年 | 118篇 |
1990年 | 121篇 |
1989年 | 117篇 |
1988年 | 129篇 |
1987年 | 102篇 |
1986年 | 121篇 |
1985年 | 139篇 |
1984年 | 135篇 |
1983年 | 116篇 |
1982年 | 129篇 |
1981年 | 121篇 |
1980年 | 124篇 |
1979年 | 93篇 |
1978年 | 118篇 |
1977年 | 91篇 |
1976年 | 85篇 |
1975年 | 71篇 |
1974年 | 61篇 |
1973年 | 57篇 |
1972年 | 45篇 |
排序方式: 共有8679条查询结果,搜索用时 312 毫秒
991.
992.
T. Kesavan Zuhair A. Hassan Helen H. Jensen Stanley R. Johnson 《Revue canadienne d'agroeconomie》1993,41(2):139-153
Empirical analysis, based on a general dynamic Almost Ideal Demand System, shows the commonly used autoregressive and partial adjustment processes are restrictive to meat demand data. This study derives a linear specification in levels form to investigate dynamics in a general framework. Merging a long-run steady state structure with short-run dynamics results in consistent and robust long-run demand elasticities Une analyse empirique, basée sur un systéme dynamique général de demande quasi optimale, montre que les mécanismes courants d'ajustement autorégressif et d'ajustement partiel ont un effect restrictif sur l'évaluation des données de la demande de viande. Les auteurs proposent une spécifcation linéaire par niveaux pour examiner la dynamique du cadre général. La combinaison d'une structure stable de longue durée avec une dynamique de courte période a produit des élasticités cohérentes et solides de la demande à long terme 相似文献
993.
Finding ration sequences which result in maximum profit per day from fattening batches of livestock over successive weight intervals has posed difficulties in earlier studies. Fractional and dynamic programming are considered as solution methods and illustrated for a problem previously solved by total enumeration. Other problems are discussed which would be best solved by a combination of the two methods. A novel proposal is made for using the two methods to maximise the present value of returns from sequencing weight gains over infinite production cycles. 相似文献
994.
The cost of flooding on farm land depends on land use, on the frequency, seasonality, duration and depth of flooding, and on water quality. This paper describes a method to calculate the average annual cost of flooding and the extra benefits or costs associated with given changes in flooding regime, illustrated by means of a simplified case study which examines the agricultural benefits of reduced summer flooding on grass in an area of environmental importance. Using hydrological and agro-economic data, the method derives the cost of individual flood events occurring in any one month for a given land use, weights these according to observed seasonality of flood flows, and derives average annual costs per hectare and for the floodplain as a whole for given levels of flood risk. The method is useful for appraising river flood alleviation schemes whereby the effects of changes in flood risk, flood seasonality or land use can be assessed. 相似文献
995.
996.
A combination of reasoning and simple regression equations are used to examine the recent history of some aspects of the dairy industry. Attention is dawn to some of the pitfalls in attempting to quantify dairy demand and supply relationships. Elasticities are generally confirmed to be low, with the exception of the demand for cream; though it is suggested that the supply of milk may be less unresponsive to price change than is often maintained. The results obtained are related to milk marketing policy. 相似文献
997.
We analyze precautionary saving behavior in a framework with labor and nonlabor income risks, an endogenous supply of labor, and a representation of preferences that disentangles attitudes toward risk, attitudes toward intertemporal substitution, and ordinal preferences for consumption and leisure. This preference structure allows us to disentangle and to describe in an intuitive way the different forces that determine precautionary saving “in the small” and “in the large.” 相似文献
998.
999.
We propose a two-stage procedure to estimate conditional beta pricing models that allows for flexibility in the dynamics of asset betas and market prices of risk (MPR). First, conditional betas are estimated nonparametrically for each asset and period using the time-series of previous data. Then, time-varying MPR are estimated from the cross-section of returns and betas. We prove the consistency and asymptotic normality of the estimators. We also perform Monte Carlo simulations for the conditional version of the three-factor model of Fama and French (1993) and show that nonparametrically estimated betas outperform rolling betas under different specifications of beta dynamics. Using return data on the 25 size and book-to-market sorted portfolios, we find that the nonparametric procedure produces a better fit of the three-factor model to the data, less biased estimates of MPR and lower pricing errors than the Fama–MacBeth procedure with betas estimated under several alternative parametric specifications. 相似文献
1000.
Prior studies conclude that firms’ equity underperforms following many individual sorts of external financing. These conclusions naturally raise significant questions about market efficiency and/or about the techniques used to measure long-run “abnormal returns.” Rather than concentrating on a single security type or issuance, we examine long-run performance following any and all sorts of security issuances. Initial financing events do not associate with underperformance; however, subsequent financings do. Our results suggest that negative post-issuance returns have nothing to do with the specific type of security issued, and everything to do with the number of types of securities issued. 相似文献