全文获取类型
收费全文 | 2676篇 |
免费 | 260篇 |
国内免费 | 25篇 |
专业分类
财政金融 | 144篇 |
工业经济 | 173篇 |
计划管理 | 643篇 |
经济学 | 689篇 |
综合类 | 402篇 |
运输经济 | 28篇 |
旅游经济 | 20篇 |
贸易经济 | 253篇 |
农业经济 | 310篇 |
经济概况 | 299篇 |
出版年
2024年 | 3篇 |
2023年 | 36篇 |
2022年 | 47篇 |
2021年 | 104篇 |
2020年 | 89篇 |
2019年 | 93篇 |
2018年 | 62篇 |
2017年 | 89篇 |
2016年 | 96篇 |
2015年 | 108篇 |
2014年 | 195篇 |
2013年 | 192篇 |
2012年 | 225篇 |
2011年 | 248篇 |
2010年 | 199篇 |
2009年 | 149篇 |
2008年 | 178篇 |
2007年 | 149篇 |
2006年 | 147篇 |
2005年 | 126篇 |
2004年 | 94篇 |
2003年 | 68篇 |
2002年 | 39篇 |
2001年 | 49篇 |
2000年 | 38篇 |
1999年 | 33篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有2961条查询结果,搜索用时 31 毫秒
11.
《Socio》2021
Based on the day-night PM2.5 difference of the nearest atmospheric monitoring points to measure whether there is illegal emission, this paper explores the impact of environmental protection officials' tenure (EPLT) on illegal emissions. The results show that there is a positive correlation between EPLT and illegal emissions. Stable EPLT can reduce illegal emissions by increasing environmental information disclosure and environmental subsidies. It can increase illegal emissions by weakening public pollution reporting and media supervision, environmental law enforcement and promoting corruption. In addition, EPLT can increase illegal emissions as EPLT is less than 3.55 years, while EPLT can increase illegal emissions as EPLT exceeds 6.21 years. Further, when mayor's tenure and EPLT are both stable, the promotion effect of EPLT on illegal emission is stronger. Stable company director's tenure can also aggravate the promotion effect of EPLT on illegal emissions. 相似文献
12.
Thi H.H. Nguyen Mohamed H. Elmagrhi Collins G. Ntim Yue Wu 《Business Strategy and the Environment》2021,30(5):2313-2331
This study seeks to contribute to the existing business strategy and the environment literature by examining the effect of governance structures on Chinese firms' environmental performance, and consequently ascertain the extent to which the financial performance–environmental performance nexus is moderated by governance mechanisms. Using a sample of Chinese companies from heavily polluting industries over a 5-year period, our baseline findings suggest that, on average, board size and governing board meetings are positively associated with Chinese firms' environmental performance, whilst board independence and gender diversity have positive, but insignificant association with firms' environmental performance. Our evidence suggests further that the examined internal governance mechanisms have a mixed moderating effect on the link between financial performance and environmental performance. Our findings have important implications for company executives, environmental activists, policy-makers, and regulators. Our results support insights drawn from agency, resource dependence, stakeholder, and legitimacy theories. 相似文献
13.
Joel Rabinovich 《Metroeconomica》2019,70(4):738-775
One aspect in which non‐financial corporations (NFCs) are said to be financialized is that they have been increasingly engaged in financial accumulation from which they derive a growing proportion of financial income. This is what we call the financial turn of accumulation hypothesis. In this article, we show that the evidence used to sustain it, in the U.S. setting, has to be reconsidered. Our findings show that, contrary to the financial turn of accumulation hypothesis, financial income averages 2.5% of NFCs’ total income since the 1980s, oscillating since the beginnings of the 1990s until 2005 and then declining. In terms of assets, some of the alleged financial assets might actually reflect other activities in which NFCs have been increasingly engaged, such as tax avoidance, internationalization of production, activities refocusing and M&As. 相似文献
14.
为研究石家庄市在"利剑斩污"行动管控期和非管控期挥发性有机物(VOCs)的污染特性变化,在2个时间段内对石家庄市3个国控点进行采样分析。通过苏玛罐(SUMMA罐)进行样品采集,利用气相色谱/质谱联用(GC/MS)仪对石家庄市区3个国控点的VOCs进行定性定量检测分析。结果表明,监测期间主要的特征污染物是二氯甲烷、二氯丙烷、苯和甲苯。与非管控期间相比,管控期间各污染物的质量浓度均有所降低,总VOCs平均质量浓度降低45.107μg/m~3,二氯甲烷质量浓度降低8.796μg/m~3,二氯丙烷质量浓度降低3.750μg/m~3,苯质量浓度降低18.285μg/m~3,甲苯质量浓度降低16.895μg/m~3。大气环境调控策略的实施,有效降低了VOCs浓度,减少了空气污染程度,空气质量改善效果显著。"利剑斩污"行动期间采取的相关举措,对于制定常态化下VOCs的防治对策具有一定的参考价值。 相似文献
15.
This article aims to improve the predictive ability of KMV model by distinguishing firm size. The evidence suggests that default point would vary with firm size. Using the method of particle swarm optimization, we obtain the optimal default point separately for large firms and small firms. Several statistical tests such as the model confidence set methodology show that our relatively tractable model is more likely to have the strongest predictive ability. 相似文献
16.
《Socio》2021
Haze pollution has become a new threat to China's sustainable development, but it may be that local government behaviour can play an important role in the prevention and control of pollutants. A dynamic spatial autoregressive (SAR) model is used to study the relationship between local government competition and haze pollution. To further explore the indirect impact of factor market distortion on haze pollution and control potential endogeneity problems, a newly developed intermediary effect model that incorporates the characteristics of the generalized method of moments (GMM) is utilized to explore how factor market distortion indirectly affects haze pollution. The research results show that regional haze pollution in China is characterized by significant spatial correlation, and local government competition has a positive impact on haze pollution; that is, local government competition exacerbates haze pollution. In general, local government competition not only directly leads to an increase in haze pollution but also further intensifies it by distorting the local factor market, and the intermediary role of factor market distortion is approximately 7.04%. The results of the regional inspection found that competition among local governments in the eastern region did not lead to haze pollution, and distortion of the factor market did not exist as an intermediary effect. However, both direct and intermediary effects are significant in the central and western regions. Therefore, an official performance appraisal system that includes ecological constraints should be established to guide the benign transformation of local government competition, and an environmental management mechanism must be developed for joint prevention and control to reduce haze pollution. In addition, the free flow of factors and marketization are equally important. 相似文献
17.
18.
在咸阳市区采集表层土壤样品60个,包括交通主干道路两侧、城市公园、住宅小区、工矿企业周边区域4类典型功能区。采用原子吸收分光光度法测定土壤样品中Cr(铬)、Cu(铜)、Ni(镍)、Pb(铅)、Zn(锌)5种重金属的含量,运用污染指数评价法、潜在生态风险指数法对土壤重金属的污染现状及风险进行评价。结果表明:(1)咸阳市土壤中Cr、Cu、Ni、Pb、Zn 5种重金属的平均含量分别为65.11、26.91、29.81、38.26、90.94mg/kg,均超过陕西省土壤重金属元素背景值;不同城市功能区土壤重金属含量水平具有明显的差异。(2)从土壤重金属单因子污染指数来看,除重金属Pb在城市公园为中度污染外,其余元素在不同功能区及整个咸阳市均为轻度污染;从土壤重金属综合污染指数来看,不论是咸阳市还是不同功能区,其土壤环境质量等级均属于轻污染。(3)不论是综合潜在生态风险还是单个重金属元素潜在生态风险,咸阳市及不同功能区都属于低生态风险水平,且重金属Pb对综合潜在生态风险的贡献率最大(37.56%)。(4)5种重金属(Cr、Cu、Ni、Pb、Zn)对儿童和成人的非致癌风险均很小;人体(儿童和成人)暴露土壤中,Ni的综合致癌风险在可接受范围内,但明显高于下限值,而Cr的综合致癌风险则是显著的;人体(儿童和成人)暴露土壤重金属而产生的非致癌风险和致癌风险的主要途径是直接摄入和皮肤接触。 相似文献
19.
针对某老式卫星返回时雷达跟踪数据曾发生的测量异常及质量较差等情况,为解决此类数据在返回弹道及落点计算中出现的实际困难以及给出应对措施,基于工程实际情况给出了三种不同建模类型下的弹道计算方法——当前统计解耦扩展卡尔曼滤波(EKF)、动力学建模无迹卡尔曼滤波(UKF)、多项式滑窗最小二乘估计算法,并应用该次质量较差的实际观测数据进行了算法应用效果分析与落点计算情况对比,对计算中的经验及教训进行了总结。研究结果表明,所给出的三种算法在面对较差质量数据时性能差异较大,在工程实际应用中可考虑将多种算法互为参考。研究结果及其经验教训对卫星返回弹道及落点的实时估计的工程实施有一定的参考价值。 相似文献
20.
《International Journal of Forecasting》2020,36(2):480-488
We develop an algorithm that forecasts cascading events, by employing a Green’s function scheme on the basis of the self-exciting point process model. This method is applied to open data of 10 types of crimes happened in Chicago. It shows a good prediction accuracy superior to or comparable to the standard methods which are the expectation–maximization method and prospective hotspot maps method. We find a cascade influence of the crimes that has a long-time, logarithmic tail; this result is consistent with an earlier study on burglaries. This long-tail feature cannot be reproduced by the other standard methods. In addition, a merit of the Green’s function method is the low computational cost in the case of high density of events and/or large amount of the training data. 相似文献