全文获取类型
收费全文 | 20441篇 |
免费 | 649篇 |
国内免费 | 334篇 |
专业分类
财政金融 | 1287篇 |
工业经济 | 1140篇 |
计划管理 | 5366篇 |
经济学 | 3407篇 |
综合类 | 2116篇 |
运输经济 | 353篇 |
旅游经济 | 714篇 |
贸易经济 | 2711篇 |
农业经济 | 1973篇 |
经济概况 | 2357篇 |
出版年
2024年 | 94篇 |
2023年 | 333篇 |
2022年 | 366篇 |
2021年 | 531篇 |
2020年 | 725篇 |
2019年 | 506篇 |
2018年 | 483篇 |
2017年 | 677篇 |
2016年 | 608篇 |
2015年 | 656篇 |
2014年 | 1561篇 |
2013年 | 1971篇 |
2012年 | 1700篇 |
2011年 | 2105篇 |
2010年 | 1507篇 |
2009年 | 1298篇 |
2008年 | 1380篇 |
2007年 | 1225篇 |
2006年 | 1005篇 |
2005年 | 781篇 |
2004年 | 552篇 |
2003年 | 319篇 |
2002年 | 208篇 |
2001年 | 191篇 |
2000年 | 143篇 |
1999年 | 82篇 |
1998年 | 93篇 |
1997年 | 57篇 |
1996年 | 51篇 |
1995年 | 44篇 |
1994年 | 37篇 |
1993年 | 20篇 |
1992年 | 17篇 |
1991年 | 18篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Predicting the geo-temporal variations of crime and disorder 总被引:2,自引:0,他引:2
Traditional police boundaries—precincts, patrol districts, etc.—often fail to reflect the true distribution of criminal activity and thus do little to assist in the optimal allocation of police resources. This paper introduces methods for crime incident forecasting by focusing upon geographical areas of concern that transcend traditional policing boundaries. The computerised procedure utilises a geographical crime incidence-scanning algorithm to identify clusters with relatively high levels of crime (hot spots). These clusters provide sufficient data for training artificial neural networks (ANNs) capable of modelling trends within them. The approach to ANN specification and estimation is enhanced by application of a novel and noteworthy approach, the Gamma test (GT). 相似文献
52.
In-depth data analysis plus statistical modeling can produce inferentialcausal models. Their creation thus combines aspects of analysis by close inspection,that is, reason analysis and cross-tabular analysis, with statistical analysis procedures,especially those that are special cases of the generalized linear model (McCullaghand Nelder, 1989; Agresti, 1996; Lindsey, 1997). This paper explores some of the roots of this combined method and suggests some new directions. An exercise clarifies some limitations of classic reason analysis by showing how the cross tabulation of variables with controls for test factors may produce better inferences. Then, given the cross tabulation of several variables, by explicating Coleman effect parameters, logistic regressions, and Poisson log-linear models, it shows how generalized linear models provide appropriate measures of effects and tests of statistical significance. Finally, to address a weakness of reason analysis, a case-control design is proposed and an example is developed. 相似文献
53.
Jayatilleke S. Bandara 《Journal of economic surveys》1991,5(1):3-69
Abstract. The use of CGE models has gained much popularity among policy analysts in LDCs and there is a fast growing body of literature on this area of economics. In this survey, the advantages of general equilibrium approach over partial equilibrium approach in analysing a wide range of policy issues are highlighted. The evolution of CGE modelling is discussed and more than 60 CGE applications related to different policy issues in LDCs are surveyed. This comprehensive survey shows that the CGE models have become quite popular analytical tools among policy analysts in LDCs over the last decade or so. The debate in the economic profession regarding the value and appropriateness of using CGE models for policy analysis is examined in the final section of this paper. Some of the criticisms levelled at CGE models are discussed and it is argued that despite this criticism such models are capable of providing insight into important policy problems. 相似文献
54.
Nonstandard probability theory and stochastic analysis, as developed by Loeb, Anderson, and Keisler, has the attractive feature that it allows one to exploit combinatorial aspects of a well-understood discrete theory in a continuous setting. We illustrate this with an example taken from financial economics: a nonstandard construction of the well-known Black-Scholes option pricing model allows us to view the resulting object at the same time as both (the hyperfinite version of) the binomial Cox-Ross-Rubinstein model (that is, a hyperfinite geometric random walk) and the continuous model introduced by Black and Scholes (a geometric Brownian motion). Nonstandard methods provide a means of moving freely back and forth between the discrete and continuous points of view. This enables us to give an elementary derivation of the Black-Scholes option pricing formula from the corresponding formula for the binomial model. We also devise an intuitive but rigorous method for constructing self-financing hedge portfolios for various contingent claims, again using the explicit constructions available in the hyperfinite binomial model, to give the portfolio appropriate to the Black-Scholes model. Thus, nonstandard analysis provides a rigorous basis for the economists' intuitive notion that the Black-Scholes model contains a built-in version of the Cox-Ross-Rubinstein model. 相似文献
55.
Trades and Quotes: A Bivariate Point Process 总被引:3,自引:0,他引:3
This article formulates a bivariate point process to jointlyanalyze trade and quote arrivals. In microstructure models,trades may reveal private information that is then incorporatedinto new price quotes. This article examines the speed of thisinformation flow and the circumstances that govern it. A jointlikelihood function for trade and quote arrivals is specifiedin a way that recognizes that an intervening trade sometimescensors the time between a trade and the subsequent quote. Modelsof trades and quotes are estimated for eight stocks using Tradeand Quote database (TAQ) data. The essential finding for thearrival of price quotes is that information flow variables,such as high trade arrival rates, large volume per trade, andwide bidask spreads, all predict more rapid price revisions.This means prices respond more quickly to trades when informationis flowing so that the price impacts of trades and ultimatelythe volatility of prices are high in such circumstances. 相似文献
56.
57.
This paper synthesizes recent research and new empirical findings to build a more comprehensive understanding of developments in China’s dairy sector. China’s tremendous rise in dairy demand has been driven by several mutually reinforcing factors: including rapid income growth, promotion by the government and dairy industry, changes in urban lifestyles, and the development of new, more sophisticated marketing channels. Domestic milk output has grown to satisfy rising demand largely by increasing the dairy herd. Substantial increases in productivity have been achieved through technology adoption, but there is evidence that the torrid growth has created inefficiencies because adaptations to marketing rules, infrastructure, and institutions have not kept pace with the changing environment. These results suggest there is ample room for future growth in both domestic milk production and dairy demand, but multinational firms and imported products will likely play and increasing role as China’s dairy market continues to develop. 相似文献
58.
GONG Yan-fen PING Yu-lan 《美中经济评论(英文版)》2008,7(5):59-64
This article classified gas exploration risk on the basis of the characteristics of oil-gas exploration investment projects, which are internal systems risk and external non-systemic risk. It described each classification specifically and introduced the basic principles and mathematical model of the multi-factor hierarchical fuzzy comprehensive judgment in detail, and then researched the conducts the risk of the gas exploration with examples. 相似文献
59.
Christopher G. Leggett 《Environmental and Resource Economics》2002,23(3):343-355
This paper considers welfare analysis with therandom utility model (RUM) when perceptions ofenvironmental quality differ from objectivemeasures of environmental quality. Environmental quality is assumed to be anexperience good, so that while perceptions ofquality determine choices, ex postutility is determined by objective quality. Given this assumption, I derive a measure ofthe welfare impact of changes in environmentalquality, and I show how this new welfaremeasure differs from the traditional welfaremeasure developed by Hanemann (1982). This newwelfare measure provides an approach tomeasuring the value of information aboutenvironmental quality within the framework ofthe random utility model. 相似文献
60.
Bayesian MCMC Mapping of Quantitative Trait Loci in a Half-sib Design: a Graphical Model Perspective
N.A. Sheehan B. Gulbrandtsen M.S. Lund D.A. Sorensen 《Revue internationale de statistique》2002,70(2):241-267
Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example. 相似文献