全文获取类型
收费全文 | 37947篇 |
免费 | 833篇 |
专业分类
财政金融 | 7078篇 |
工业经济 | 3022篇 |
计划管理 | 6451篇 |
经济学 | 8455篇 |
综合类 | 377篇 |
运输经济 | 290篇 |
旅游经济 | 667篇 |
贸易经济 | 5903篇 |
农业经济 | 1868篇 |
经济概况 | 4596篇 |
邮电经济 | 73篇 |
出版年
2021年 | 240篇 |
2020年 | 422篇 |
2019年 | 577篇 |
2018年 | 767篇 |
2017年 | 749篇 |
2016年 | 721篇 |
2015年 | 543篇 |
2014年 | 811篇 |
2013年 | 3827篇 |
2012年 | 1039篇 |
2011年 | 1157篇 |
2010年 | 954篇 |
2009年 | 1162篇 |
2008年 | 1187篇 |
2007年 | 1049篇 |
2006年 | 1011篇 |
2005年 | 921篇 |
2004年 | 903篇 |
2003年 | 923篇 |
2002年 | 846篇 |
2001年 | 812篇 |
2000年 | 811篇 |
1999年 | 704篇 |
1998年 | 709篇 |
1997年 | 688篇 |
1996年 | 655篇 |
1995年 | 598篇 |
1994年 | 633篇 |
1993年 | 637篇 |
1992年 | 586篇 |
1991年 | 609篇 |
1990年 | 549篇 |
1989年 | 469篇 |
1988年 | 469篇 |
1987年 | 474篇 |
1986年 | 464篇 |
1985年 | 675篇 |
1984年 | 658篇 |
1983年 | 647篇 |
1982年 | 616篇 |
1981年 | 512篇 |
1980年 | 516篇 |
1979年 | 520篇 |
1978年 | 436篇 |
1977年 | 400篇 |
1976年 | 330篇 |
1975年 | 297篇 |
1974年 | 294篇 |
1973年 | 280篇 |
1972年 | 214篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jo J. Voola 《Economics of Innovation and New Technology》2013,22(3):271-288
This paper is a case study of the impact of an exogenous improvement of a process technology on the structure of the petroleum industry. The paper examines the role of three-dimensional seismology in bringing about the 1990s oil industry consolidation. This proposition is examined in the context of evolutionary economics and in a non-cooperative game theory, concluding with a reference to Steindl's theory of industry dynamics. The significance of this contribution lies chiefly in highlighting the fact that exogenous technological change can, under appropriate conditions, play a significant role in industry dynamics. This reference to the exogenous change in technology is a departure from the traditional consideration of endogenity of industry structure in relation to technological development and, therefore, a novelty. Secondly, the documentation of 3D seismology as a significant process technology of the petroleum industry is significant. 相似文献
992.
This study examines the incidence of research and development (R&D) activities, type of R&D undertaken and the incidence of R&D co-operation among manufacturing firms located in a key urban area of the North East England, a peripheral region of the UK. We have found that over 62% of manufacturing firms in this urban growth area to be R&D active, suggesting that R&D active firms tend to be concentrated in urban area s in a peripheral region, as it is the case in the leading regions. However, the incidence of R&D co-operation was found to be relatively low among R&D active firms. It is also found that the key determinants of undertaking R&D to be the existence of a core competence/product and exporting activities. These findings might be of interest to policy makers promoting economic growth via firm’s R&D activities. 相似文献
993.
J. M. Plehn-Dujowich 《Economics of Innovation and New Technology》2013,22(3):205-223
We propose a general theory of innovation that illustrates the relative benefits of performing process versus product R&D when firm size is endogenous. A firm's size, scope, and R&D portfolio are shown to reflect the same underlying characteristic of the firm, namely manufacturing efficiency. We demonstrate that efficient firms become larger, have greater scope, and perform more of both process and product R&D. In light of decreasing returns to R&D, this implies small firms obtain more product innovations per dollar of R&D than large firms, which is consistent with evidence we present that small firms are more innovative than large firms as they obtain more patent counts and citations per dollar of R&D. 相似文献
994.
We offer empirical information on the correlates of commercialization activity for research projects funded through the US National Institutes of Health's (NIH's) Small Business Innovation Research (SBIR) award program. Based on this analysis we suggest possible recommendations for improving this aspect of the performance of NIH's SBIR program. Specifically, we estimate a model of the probability of commercialization as a function of the project's ability to attract additional developmental funding, along with other control variables. We find that additional developmental funding from non-SBIR federal sources and from own internal sources are important predictors of commercialization success, relatively more so than additional developmental funding from venture capitalists. We also find, among other things, that university involvement in the underlying research increases the probability of commercialization. Thus, these factors should be considered by NIH when making awards, if increased commercialization is an objective. 相似文献
995.
We examine the market power of a seller who repeatedly offers upgraded versions of a product. In the case of pure monopoly, the seller also controls compatibility across versions. In the case of an entrant who offers an upgrade, the incumbent seller also controls subsequent interoperability across versions. We argue that control of compatibility and interoperability does not allow an incumbent seller to charge a price premium relative to when such control is absent and, consequently, neither is a necessary source of market power. 相似文献
996.
It is well established that knowledge-intensive business service (KIBS) firms can be innovators in their own right. It is also well established that KIBS can contribute to innovation in their client firms. This role of KIBS has been theorised, and some of the processes by which KIBS contribute to innovation have been scrutinised by way of case studies. However, there are few, if any, large-scale analyses that permit the two following questions to be addressed: (i) Do firms that use KIBS systematically introduce more innovations than those that do not? (ii) Is recourse to certain types of KIBS associated with certain types of innovation? Our survey of KIBS use across 804 manufacturing establishments in Quebec shows that KIBS contribute to their client's innovation – thereby confirming in a more general way what has been observed in case studies – but also that different types of KIBS contribute to different types of innovation. 相似文献
997.
Abstract This paper reports on the findings of a survey of top economics graduate schools as they relate to women and men. The results provide strong evidence that at these top graduate schools, women graduate students are less integrated in their economic disciplines than are male graduate students. In the second part of the paper, this paper relates those findings to alternative theories as to why this is the case. This paper concludes by suggesting that the emphasis on theoretical studies in the current core of the graduate economics program can be seen as a type of hazing process that seems to have a significant cost since many women (and men) with great creative promise are discouraged from continuing in economics and do not benefit nearly as much as they would have from more policy-driven core courses. 相似文献
998.
Jue Wang George Athanasopoulos Rob J. Hyndman Shouyang Wang 《International Journal of Forecasting》2018,34(4):665-677
The growing internet concern (IC) over the crude oil market and related events influences market trading, thus creating further instability within the oil market itself. We propose a modeling framework for analyzing the effects of IC on the oil market and for predicting the price volatility of crude oil’s futures market. This novel approach decomposes the original time series into intrinsic modes at different time scales using bivariate empirical mode decomposition (BEMD). The relationship between the oil price volatility and IC at an individual frequency is investigated. By utilizing decomposed intrinsic modes as specified characteristics, we also construct extreme learning machine (ELM) models with variant forecasting schemes. The experimental results illustrate that ELM models that incorporate intrinsic modes and IC outperform the baseline ELM and other benchmarks at distinct horizons. Having the power to improve the accuracy of baseline models, internet searching is a practical way of quantifying investor attention, which can help to predict short-run price fluctuations in the oil market. 相似文献
999.
David S.A. Guttormsen 《Scandinavian Journal of Management》2018,34(3):233-244
Non-Traditional Expatriates (NTEs) are rapidly increasing in the global talent pool, but remains a ‘black-box’ in the Expatriate Management and Global Mobility literatures. This article advances the conceptualisation of NTEs, due to the nascent research field is lacking construct clarity in terms of the meaning of the term as well as an operationalised conceptual framework. Five underlying assumptions in the scarce extant literature are identified and discussed, as a means to responding to the following research questions: (i) how credible is the NTE term as an expatriation typology?; and (ii) how can the conceptual framework of NTEs be operationalised? If these key issues remain unsolved, there is a risk of establishing flawed research design which can negatively affect researchers’ credibility when providing policy advice on global staffing and talent management to international managers and Multinational Enterprises (MNEs). This conceptual article draws upon key social anthropological and sociological theories, and proposes a relational research design for investigating NTEs, as well as propositions for future research. 相似文献
1000.
Ella Y. Henry Leo-Paul Dana Patrick J. Murphy 《Entrepreneurship & Regional Development》2018,30(1-2):118-145
We examined how factors from Indigenous entrepreneurship research (social capital, cultural capital, self-efficacy) help explain the high level of Māori entrepreneurial performance in the mainstream screen industry. Results, based on ten case studies and a one-year series of structured interviews, extend prior research by showing that these Indigenous entrepreneurs benefit jointly from two forms of capital: cultural and social. We found high levels of both forms to increase the desire for emancipation of cultural and community identity – not just individual identity – through entrepreneurship. Self-efficacy and storytelling helped ameliorate discontinuities across Indigenous and mainstream contexts. Our research sheds new light on how Indigenous ventures can pursue mainstream entrepreneurship while maintaining cultural identity. It also makes several distinct contributions to the Indigenous entrepreneurship literature. First, it provides an integrative theoretic review. Second, it illustrates a culturally appropriate methodology for researching Māori entrepreneurs with implications for other Indigenous communities. Third, it proposes cultural capital and social capital as a two-part framework for explaining Indigenous entrepreneurial action. Fourth, it shows how entrepreneurship can be empowering for Indigenous communities. Finally, our paper demonstrates that entrepreneurship is a promising mechanism for preserving and promoting the cultures of Māori and other Indigenous peoples. 相似文献