全文获取类型
收费全文 | 8689篇 |
免费 | 466篇 |
国内免费 | 189篇 |
专业分类
财政金融 | 946篇 |
工业经济 | 417篇 |
计划管理 | 1968篇 |
经济学 | 1719篇 |
综合类 | 1140篇 |
运输经济 | 106篇 |
旅游经济 | 59篇 |
贸易经济 | 804篇 |
农业经济 | 1049篇 |
经济概况 | 1136篇 |
出版年
2024年 | 48篇 |
2023年 | 192篇 |
2022年 | 232篇 |
2021年 | 300篇 |
2020年 | 306篇 |
2019年 | 221篇 |
2018年 | 203篇 |
2017年 | 285篇 |
2016年 | 267篇 |
2015年 | 349篇 |
2014年 | 656篇 |
2013年 | 701篇 |
2012年 | 755篇 |
2011年 | 820篇 |
2010年 | 623篇 |
2009年 | 485篇 |
2008年 | 556篇 |
2007年 | 509篇 |
2006年 | 479篇 |
2005年 | 368篇 |
2004年 | 213篇 |
2003年 | 203篇 |
2002年 | 143篇 |
2001年 | 107篇 |
2000年 | 83篇 |
1999年 | 59篇 |
1998年 | 47篇 |
1997年 | 31篇 |
1996年 | 32篇 |
1995年 | 9篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有9344条查询结果,搜索用时 15 毫秒
41.
The economic impact of adopting herd health programs for mastitis and reproduction by small-scale dairy producers of Central Thailand was assessed using a policy analysis matrix (PAM). Following a reduction in the incidence of bovine disease on adopter farms, an increase in private net profits is observed. More importantly the social costs of supporting dairy farmers is reduced; the PAM effective protection coefficient was reduced by 35% for mastitis program adopters and by 44% for reproductive program adopters, indicating improved social efficiency of dairy policy. Other indicators of efficiency and policy implications are discussed. 相似文献
42.
Estimation in the interval censoring model is considered. A class of smooth functionals is introduced, of which the mean is an example. The asymptotic information lower bound for such functionals can be represented as an inner product of two functions. In case 1, i.e. one observation time per unobservable event time, both functions can be given explicitly. We mainly consider case 2, with two observation times for each unobservable event time, in the situation that the observation times can not become arbitrarily close to each other. For case 2, one of the functions in the inner product can only be given implicitly as solution to a Fredholm integral equation. We study properties of this solution and, in a sequel to this paper, prove that the nonparametric maximum likelihood estimator of the functional asymptotically reaches the information lower bound. 相似文献
43.
Are Housing Price Cycles Driven by Irrational Expectations? 总被引:3,自引:0,他引:3
This paper investigates the extent to which condominium apartment prices are set in an efficient asset market. Unlike previous work that focuses on the time-series properties of measures of excess returns, the analysis is framed in terms of the changes in observable house prices over time. More precisely, the paper develops and applies a test of the joint null hypothesis of rational expectations, perfect markets, and no risk premium in the Vancouver condominium apartment market. The empirical results provide significant evidence against the joint null hypothesis. On average, ex post house price changes move in a direction opposite to their rational expectation. This approach offers a methodological advantage over the standard efficiency literature and is shown to provide a more powerful test of market efficiency than conventional return regressions. Another contribution of the paper is to characterize the time-series properties of deviations of condominium prices from those predicted by the risk-neutral rational expectations model, using cointegration and random coefficients techniques. Deviations in house price changes from their (risk-neutral) rational expectations are time varying, stationary, and related to the stage of the real estate price cycle. 相似文献
44.
This paper employed eleven data series which consist of stocks, bonds, bills, equity premiums, term premiums, and various default premiums to investigate whether January seasonality reported in existing literature is robust across different states of the economy as this has important trading implications. For the periods 1926–1990, small stocks, small stock premiums, low grade bonds, and default premiums (spread between high grade, low grade and government bonds) reveal January seasonality and that the seasonality is robust across different states of the economy except for low grade bond returns and default premiums. January seasonality for low grade bond returns and low grade bond default premiums are primarily driven by results found during periods of economic expansion. Overall, January seasonality is more evident during the economic expansion periods although the magnitude of default premiums is larger during periods of economic contraction. Furthermore, prior findings of strong summer equity returns are primarily driven by the results found during the periods of economic contraction. It is also found that equity returns are generally higher during periods of economic expansion. 相似文献
45.
素质教育的一个重要部分就是学生综合应用能力及探究能力的培养。笔者针对导游专业的特点,在计算机基础教学中引入任务性学习方式,改善了教学效果,提高了该专业学生的计算机综合应用能力及自主探究能力。 相似文献
46.
On the Role of Weight Restrictions in Data Envelopment Analysis 总被引:3,自引:3,他引:0
Pedraja-Chaparro Francisco Salinas-Jimenez Javier Smith Peter 《Journal of Productivity Analysis》1997,8(2):215-230
This paper examines the role that weight restrictions play in Data Envelopment Analysis (DEA). It is argued that the decision to include a factor (input or output) in a DEA model represents an implicit judgement that the factor has a non-trivial weight. It therefore seems perverse to allow DEA to assign a trivial weight to that factor in assessing the efficiency of a unit. There is therefore a strong case for imposing restrictions on factor weights. However, many existing methods of weight restriction are in practice unwieldy. This paper proposes an alternative approach we term contingent weight restriction which is both practical and intellectually consistent with the DEA philosophy. The paper explores the implications of alternative methods of weight restriction using simulated data from a well known production process. 相似文献
47.
International mutual funds allow individual investors to diversify abroad at a reasonable cost. This paper tests whether international funds that actively engage in country and security selection outperform passive global benchmarks. We apply a mean-variance efficiency test that incorporates the practical prohibition against short sales of open-end mutual funds. Our tests reject the efficiency of the world equity market portfolio over the sample period, and our funds as a group outperform the inefficient world index. However, we find no evidence of security selectivity ability using a 12-country benchmark. We do find that active international funds provide global diversification benefits. Tests using the Positive Period Weight (PPW) measure of Grinblatt and Titman (1989), which is robust to nonlinearity in fund and benchmark returns, yield similar results. 相似文献
48.
Summary The exact mean square error for the ratio estimator of a finite population total based on simple random sampling without replacement
is shown to have an expected value less than that of the variance of the ratio estimator based on Midzuno’s scheme, under
a usual super-population model. 相似文献
49.
Silva Portela Maria Conceição A. Borges Pedro Castro Thanassoulis Emmanuel 《Journal of Productivity Analysis》2003,19(2-3):251-269
This paper draws attention for the fact that traditional Data Envelopment Analysis (DEA) models do not provide the closest possible targets (or peers) to inefficient units, and presents a procedure to obtain such targets.It focuses on non-oriented efficiency measures (which assume that production units are able to control, and thus change, inputs and outputs simultaneously) both measured in relation to a Free Disposal Hull (FDH) technology and in relation to a convex technology. The approaches developed for finding close targets are applied to a sample of Portuguese bank branches. 相似文献
50.
地下管线的主要特点是隐蔽性,地下分布纵横交错,年代已久的原有手工数据几乎无参考价值且存档不便、使用复杂、工作量大。使用自主开发升级后的计算机程序软件,不仅可以大大提高地下管线测量数据的更新、规划设计及施工的效率,而且可以通过CAD图形分析对特殊地段重要管线是否保留利用作出决定。 相似文献