全文获取类型
收费全文 | 19215篇 |
免费 | 398篇 |
国内免费 | 1篇 |
专业分类
财政金融 | 3214篇 |
工业经济 | 1402篇 |
计划管理 | 3110篇 |
经济学 | 4270篇 |
综合类 | 460篇 |
运输经济 | 94篇 |
旅游经济 | 213篇 |
贸易经济 | 3475篇 |
农业经济 | 693篇 |
经济概况 | 2633篇 |
信息产业经济 | 4篇 |
邮电经济 | 46篇 |
出版年
2021年 | 99篇 |
2020年 | 182篇 |
2019年 | 284篇 |
2018年 | 949篇 |
2017年 | 950篇 |
2016年 | 690篇 |
2015年 | 205篇 |
2014年 | 362篇 |
2013年 | 1427篇 |
2012年 | 566篇 |
2011年 | 1091篇 |
2010年 | 954篇 |
2009年 | 911篇 |
2008年 | 861篇 |
2007年 | 967篇 |
2006年 | 357篇 |
2005年 | 374篇 |
2004年 | 404篇 |
2003年 | 448篇 |
2002年 | 360篇 |
2001年 | 312篇 |
2000年 | 330篇 |
1999年 | 277篇 |
1998年 | 298篇 |
1997年 | 260篇 |
1996年 | 279篇 |
1995年 | 243篇 |
1994年 | 205篇 |
1993年 | 245篇 |
1992年 | 243篇 |
1991年 | 247篇 |
1990年 | 237篇 |
1989年 | 195篇 |
1988年 | 169篇 |
1987年 | 182篇 |
1986年 | 199篇 |
1985年 | 255篇 |
1984年 | 226篇 |
1983年 | 193篇 |
1982年 | 173篇 |
1981年 | 191篇 |
1980年 | 182篇 |
1979年 | 178篇 |
1978年 | 161篇 |
1977年 | 116篇 |
1976年 | 120篇 |
1975年 | 112篇 |
1974年 | 88篇 |
1973年 | 105篇 |
1972年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
In this paper, we focus on the question to what extent machine learning (ML) tools can be used to support systematic literature reviews. We apply a ML approach for topic detection to analyze emerging topics in the literature—our context is accounting and finance research in the Asia–Pacific region. To evaluate the robustness of the approach, we compare findings from the automated ML approach with the results from a manual analysis of the literature. The automated approach uses a keyword algorithm detection mechanism whereby the manual analysis uses common techniques for qualitative data analysis, that is, triangulation between researchers (expert judgement). From our paper, we conclude that both methods have strengths and weaknesses. The automated analysis works well for large corpora of text and provides a very standardized and non-biased way of analyzing the literature. However, the human researcher is potentially better equipped to evaluate current issues and future trends in the literature. Overall, the best results might be achieved when a variety of tools are used together. 相似文献
22.
Germano Mwabu Mwangi S. Kimenyi Paul K. Kimalu Nancy Nafula Damiano Kulundu Manda 《Revue africaine de developpement》2003,15(1):77-85
Household surveys provide data that is used for identifying and measuring the poverty status of households and individuals. However, carrying out such surveys is expensive, especially in poor developing countries. Thus it is important to make maximum use of the available survey data in developing countries, especially in sub‐Saharan Africa, where such data are expensive to collect and analyse. This paper develops a simple method for using poverty indices derived from survey data for a given year, to predict poverty rates for subsequent periods without having to conduct a new household survey. We illustrate the workings of the method with data from Kenyan household surveys for 1994 and 1997. 相似文献
23.
The Local Whittle Estimator of Long-Memory Stochastic Volatility 总被引:1,自引:0,他引:1
We propose a new semiparametric estimator of the degree of persistencein volatility for long memory stochastic volatility (LMSV) models.The estimator uses the periodogram of the log squared returnsin a local Whittle criterion which explicitly accounts for thenoise term in the LMSV model. Finite-sample and asymptotic standarderrors for the estimator are provided. An extensive simulationstudy reveals that the local Whittle estimator is much lessbiased and that the finite-sample standard errors yield moreaccurate confidence intervals than the widely-used GPH estimator.The estimator is also found to be robust against possible leverageeffects. In an empirical analysis of the daily Deutsche Mark/USDollar exchange rate, the new estimator indicates stronger persistencein volatility than the GPH estimator, provided that a largenumber of frequencies is used. 相似文献
24.
25.
Eric F. Parkinson 《International Journal of Technology and Design Education》2004,14(3):219-243
Construction kits have played a significant part in nurturing the growth and development of the minds and manipulation-based
skills of children (and adults) in formal and non-formal education settings. These kits have origins rooted in the representation
of the built world and now have a diversity of form and function, including technical versions with moving parts. This article
examines some of the historically based ideas that lie behind the role that kits may have in terms of physical modelling.
The article traces the transformation of kits from simple bricks and blocks into more complicated pieces for space-filling
and achieving the transfer of forces and motion. This transformation occurred during the Victorian era when the influence
of the ideas of educationalists and, perhaps rather strangely, exponents of early aviation, played major roles in determining
the diversity of forms of construction kit and modelled possibilities that are now to be seen in classrooms and homes. The
article ends with a review of some of the lessons from the past and present that will need to be considered in relation to
concrete modelling in schools for the future.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
26.
Rudy K. Moenaert Dirk Deschoolmeester Arnoud De Meyer William E. Souder 《R&D Management》1992,22(1):021-040
Abstract The research question in the present article can be phrased in the following way: what are the elements which influence the perception of the utility of information received from another function? A field study research has been conducted in 40 Belgian companies. In each company, we have studied two on-going innovation projects (one planning project, one development project). Crossfunctional communication behaviours at the R&D/marketing interface have been measured by means of mailed structured questionnaires. Three-hundred and eighty-six questionnaires have been returned. The data analyses show that there are four underlying information dimensions, i.e. the perceived relevance, the perceived comprehensibility, the perceived novelty and the perceived credibility of information. We also discuss some contingency variables (function of the message receiver, stage in the innovation process) that might moderate the impact of these dimensions. It will be shown that the interaction between source and receiver has a significant impact on the perceived credibility, the perceived comprehensibility and the perceived novelty of the received information. 相似文献
27.
The paper extends Manning's model on education and balanced growth to include labour immigration. Each immigration unit is assumed to consist of one skilled worker and some unskilled members. The optimal immigration policy which maximizes the per capita steady-state consumption of the host country is derived. We show that optimal immigration policy can reduce the steady-state skilled labour ratio. More interesting still, contrary to the widespread belief that immigration of skilled workers hurts local skilled workers, it is the unskilled local workers whose interests are threatened by optimal immigration policy. 相似文献
28.
The introduction of traffic management schemes has been one response of the National Parks to the problem of ever-increasing car-borne visitors and the consequent damage caused to the rural environment. By reviewing these schemes and by determining and explaining attitudes towards one particular traffic management experiment, the paper aims to deduce lessons for future policy. The analysis, based on two visitor surveys, suggests that the likelihood of success is improved when schemes are integrated, containing both ‘carrot’ and ‘stick’ elements. Since public perceptions are also found to be pivotal to its success, appropriate marketing of a scheme is vital. The paper concludes, however, that to achieve the fundamental objective of greater accessibility with less mobility, a more wide-ranging marketing effort is required intended to engender a sea change in attitude towards both the car and public transport. 相似文献
29.
The paper deals with effects of price changes on measurement of poverty. It is shown that there are situations, when prices and nominal incomes change, a higher nutritional intake or an increase in commodity consumption of the poor can be associated with higher poverty gaps and a higher poverty index of the society. A positive relationship of this kind is quite counter-intuitive in the context of poverty measurement. This is caused by the adjustment of the poverty line and/or incomes of one situation by the prices of the other for the purpose of comparison.
相似文献30.
This paper investigates India's exceptional development pattern, specifically the major importance of information technology services (ITS), and compares it with China's development pattern. Both countries want to develop capabilities for carrying out the innovation of technologies that compete at the state-of-the-art in the world market. The paper posits that technological/economic success in the contemporary world market requires the ability to innovate complex technologies and complex technology-related services. The share of trade represented by complex technologies is compared with the “high-tech” share. The trading patterns of the two countries are compared using United Nations data. Two case studies of Indian ITS companies are then compared with two case studies of Chinese manufacturing companies. Historical and cultural differences appear to explain some of the differences in the development patterns of the companies located in the two countries. 相似文献