首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   28957篇
  免费   324篇
  国内免费   1篇
财政金融   5123篇
工业经济   1661篇
计划管理   4550篇
经济学   6451篇
综合类   588篇
运输经济   110篇
旅游经济   204篇
贸易经济   6458篇
农业经济   435篇
经济概况   3059篇
信息产业经济   46篇
邮电经济   597篇
  2021年   90篇
  2020年   149篇
  2019年   231篇
  2018年   2588篇
  2017年   2382篇
  2016年   1528篇
  2015年   291篇
  2014年   401篇
  2013年   1447篇
  2012年   832篇
  2011年   2375篇
  2010年   2157篇
  2009年   1895篇
  2008年   1834篇
  2007年   2145篇
  2006年   364篇
  2005年   648篇
  2004年   743篇
  2003年   845篇
  2002年   506篇
  2001年   313篇
  2000年   279篇
  1999年   210篇
  1998年   236篇
  1997年   216篇
  1996年   203篇
  1995年   160篇
  1994年   162篇
  1993年   170篇
  1992年   184篇
  1991年   192篇
  1990年   139篇
  1989年   133篇
  1988年   115篇
  1987年   127篇
  1986年   156篇
  1985年   180篇
  1984年   161篇
  1983年   197篇
  1982年   160篇
  1981年   142篇
  1980年   162篇
  1979年   143篇
  1978年   120篇
  1977年   132篇
  1976年   122篇
  1975年   114篇
  1974年   105篇
  1973年   86篇
  1971年   67篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
31.
The new regulatory framework in the digital sector in Europe is likely to fall short of expectations. A fragmented digital market with insuffi cient incentives for investment is the probable outcome. European regulators should abandon their approach in favour of a new and more flexible set of ideas discussed in this paper.  相似文献   
32.
Bio-economic modelling has become a useful tool for anticipating the outcomes of policies and technologies before their implementation. Advances in mathematical programming have made it possible to build more comprehensive models. In an overview of recent studies about bio-economic models applied to land-use problems in agriculture and forestry, we evaluated how aspects such as uncertainty, multiple objective functions, system dynamics and time have been incorporated into models. We found that single objective models were more frequently applied at the farm level, while multiple objective modelling has been applied to meet concerns at the landscape level. Among the objectives, social aspects are seldom represented in all models, when being compared to economic and environmental aspects. The integration of uncertainty is occasionally a topic, while stochastic approaches are more frequently applied than non-stochastic robust methods. Most multiple-objective models do not integrate uncertainty or sequential decision making. Static approaches continue to be more recurrent than truly dynamic models. Even though integrating multiple aspects may enhance our understanding of a system; it involves a tradeoff between complexity and robustness of the results obtained. Land-use models have to address this balance between complexity and robustness in order to evolve towards robust multiple-objective spatial optimization as a prerequisite to achieve sustainability goals.  相似文献   
33.
Various aspects of sustainable development and quality of life are considered, including the impact of standardization. Particular attention is paid to the study of the role played by standardization in improving environmental protection. In this connection the significance of standardization is shown as a factor of improving the technological potential of an enterprise and the quality of life. Various approaches to methods for assessing the effective impact of standardization on the quality of life are analyzed.  相似文献   
34.
In this paper, we consider the feasibility of constructing online sentiment indices, using large amounts of media data, as an alternative to the conventional survey method used to create the consumer confidence index in South Africa. A clustering framework is adopted to provide an indication of possible candidate sentiment indices constructed from a combination of different text sources and dictionaries that best mimic the traditional survey-based consumer confidence index from the South African Bureau for Economic Research (BER). The results conclude that it is possible to create an index using sentiment analysis using online editorial data that does resemble the BER’s consumer confidence index. The different media-based sentiment indices (MSI) show a significant level of correlation and co-movement with the BER’s CCI. Impulse responses and cross-correlation functions indicate that the MSI could potentially lead the survey-based method up to two quarters. Furthermore, Granger-causality tests show that the media-based indices are good predictors of future consumer confidence index values. The results provide motivation for further study on the use of sentiment-based techniques and online media data sources to track consumer confidence within an emerging market such as South Africa.  相似文献   
35.
Amid increasing interest in firm age and its effects on firm performance, this special issue offers an exhaustive review of the literature and a novel collection of evidence on the effects of firm age on performance, including a special focus of interest on innovation performance, financial performance, exports, survival and growth. This editorial positions the theme in the extant literature, and provides key definitions and challenges ahead in the field of evolutionary economics. It introduces the collection of articles composing the special issue. The papers offer a diversity of country contexts, as well as analytical approaches and methods. They include an exhaustive review of the literature on age and firms’ performance, and present original empirical studies focusing on the effects of age on firms’ economic outcomes on the one hand, and on innovation outcomes on the other hand. While most of the papers use econometric analysis, the level of analysis ranges from firm to individual.  相似文献   
36.
Aims: The Anti-Clot Treatment Scale (ACTS) and Treatment Satisfaction Questionnaire for Medication version II (TSQM-II) are validated treatment satisfaction patient-reported outcome (PRO) instruments. The ACTS includes two domains: Burdens and Benefits; the TSQM-II includes four: Effectiveness, Side Effects, Convenience, and Global Satisfaction. Japanese-language versions of the ACTS and TSQM-II have been developed and linguistically validated. This study aimed to assess their psychometric properties in Japanese patients with atrial fibrillation (AF).

Materials and methods: ACTS and TSQM-II data from 534 patients with AF were collected in a Japanese post-marketing surveillance study of a direct oral-anticoagulant, rivaroxaban. Four key psychometric properties, in line with best practice guidelines from the US Food and Drug Administration, were examined using traditional psychometric methods: acceptability, scaling assumptions, reliability (i.e. internal consistency reliability, test-retest reliability), and construct validity (i.e. convergent validity and known groups).

Results: ACTS Burdens and Benefits and TSQM-II Effectiveness, Convenience, and Global Satisfaction scales were found to be acceptable (e.g. item-level missing data at baseline <4%), with all scales having good internal consistency (Cronbach’s alpha > 0.80). test-retest reproducibility intraclass correlation coefficients for the ACTS Burdens and Benefits were 0.59 and 0.65, respectively, and between 0.54–0.61 for the TSQM-II scales. Known-groups validity for the ACTS and TSQM-II was supported by differences in scale scores by positive and negative impact (p?<?0.05). Correlations between the ACTS and TSQM-II (convergent validity) were lower than expected (range r?=?0.09–0.48), but in line with the original ACTS development study.

Limitations: Evaluation of test-retest reproducibility was limited by assessment period, which was longer (3 months) than recommended guidelines (usually up to 2 weeks).

Conclusions: Overall, Japanese versions of ACTS and TSQM-II scales satisfied internal consistency reliability and traditional validity criteria. Our study supports the ACTS and TSQM-II as appropriate PRO instruments to measure satisfaction with anticoagulant treatment in Japanese patients with AF.

Trial registration: NCT01598051, clinicaltrials.gov; registered April 20, 2012.  相似文献   
37.
The choice argument against sweatshop regulations states that public officials should not prohibit workers from accepting jobs that require long hours, low pay, and poor working conditions, because enforcing such regulations would be disrespectful to the workers who choose to work in sweatshops. Critics of the choice argument reply that these regulations can be justified when workers only choose to work in sweatshops because they lack acceptable alternatives and are unable to coordinate to achieve better conditions for all workers. My thesis is that the presence of unacceptable alternatives to sweatshop labor or barriers to coordination cannot justify sweatshop regulations such as minimum wage and maximum hour laws. Although officials should promote alternatives to difficult and dangerous sweatshop labor, they should not do so by limiting workers’ and employers’ options through coercive regulation. And the fact that sweatshop workers may face coordination problems does not undermine the claim that sweatshop workers choose to work in sweatshops, just as other workers face coordination problems but nevertheless make occupational choices. Furthermore, efforts to restrict sweatshop workers’ choices are morally risky and may not promote workers’ wellbeing or wellbeing in general.  相似文献   
38.
The study reported in this paper investigated the determinants of fair trade (FT) product purchase intention among Dutch consumers according to the extended Theory of Planned Behaviour and determined whether the effects of those determinants differ between male and female consumers. To test the various research hypotheses, an online survey with 499 respondents from a Dutch research panel was employed. Results of the multi-group analysis using a structural equation modelling approach reveal that FT product purchase intention of both male and female consumers are predicated on moral obligation and self-identity. The impact of subjective norm on purchase intention is statistically significant for male consumers only. Analyses reveal that, indeed, the impact of subjective norm on FT product purchase intention is moderated by consumers’ gender.  相似文献   
39.
40.
The aim of this research is to investigate the web of business-stakeholder relationships emerging from first integrated reports. Drawn from the stakeholder salience theory, the analysis focuses on some factors that may cause specific stakeholders to be crucial for some organizations and their ability to create value over time. More precisely, findings highlight the importance of industry membership, while entities’ nationality seems not to be a differentiating element. This study contributes to the corporate disclosure literature by analyzing an emerging reporting tool, the integrated report, and demonstrating that the link between some business characteristics and stakeholder salience seems fundamental for the representation of the impact of corporate social and environmental responsibilities on the economic performance. From a practical point of view, the impact of industry membership on corporate disclosures encourages the drafting of differentiated reporting standards across sectors, in order to improve comparability, materiality, and reliability of information.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号