全文获取类型
收费全文 | 652篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
财政金融 | 103篇 |
工业经济 | 54篇 |
计划管理 | 98篇 |
经济学 | 97篇 |
综合类 | 48篇 |
运输经济 | 47篇 |
旅游经济 | 11篇 |
贸易经济 | 120篇 |
农业经济 | 25篇 |
经济概况 | 58篇 |
出版年
2023年 | 6篇 |
2022年 | 12篇 |
2021年 | 20篇 |
2020年 | 28篇 |
2019年 | 14篇 |
2018年 | 10篇 |
2017年 | 20篇 |
2016年 | 44篇 |
2015年 | 15篇 |
2014年 | 33篇 |
2013年 | 45篇 |
2012年 | 37篇 |
2011年 | 64篇 |
2010年 | 41篇 |
2009年 | 44篇 |
2008年 | 54篇 |
2007年 | 39篇 |
2006年 | 39篇 |
2005年 | 21篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有661条查询结果,搜索用时 422 毫秒
71.
72.
目前铁路专用线运输和装卸危险化学品的安全评价,普遍使用的道化学法和TNT当量模型计算法存在计算过程烦琐、结果不直观、不方便比较和查阅、不能迅速判断事故的伤害区域等缺点。研究将MATLAB应用于专用线易燃易爆危险品装卸区安全评价,对蒸气云爆炸后果进行模拟,得出死亡半径,并将计算绘制成各种图形结果。利用MATLAB对专用线危险品装卸区进行安全评价,发挥其计算和分析优势,可以缩短评价周期,提高评价效率。 相似文献
73.
用RFID电子标签技术,设计了一套RFID电子标签考勤系统。该系统能实现多点自动考勤、数据存储、查询记录、打印报表、统一管理等功能,实现了局域网内考勤系统的网络数据共享。将该系统应用于学校考勤,解决了传统的人工考勤带来的工作繁琐、效率低下、容易疏漏等缺点。 相似文献
74.
75.
76.
Alessandro Persona Daria Battini Riccardo Manzini Arrigo Pareschi 《International Journal of Production Economics》2007,110(1-2):147
In order to control the time to market and manufacturing costs, companies produce and purchase many parts and components before receiving customer orders. Consequently, demand forecasting is a critical decision process. Using modular product design and super bills of materials are two effective strategies for developing a reliable demand forecasting process. They reduce the probability of stockouts in diversified production contexts. Furthermore, managing and controlling safety stocks for pre-assembled modules provide an effective solution to the problem of minimizing the effects of forecast errors. This paper develops, evaluates, and applies innovative cost-based analytical models so that the optimal safety stock of modular subassemblies and components in assembly to order and manufacturing to order systems, respectively, can be rapidly quantified. The implementation of the proposed models in two industrial case applications demonstrates that they significantly reduce the safety stock inventory levels and the global logistical cost. 相似文献
77.
Deploying a single nationwide broadband wireless network to serve all public safety users would have great advantages over the existing fragmented public safety systems. A nationwide system could be created to serve both public safety and commercial subscribers, which would allow a provider to exploit important economies but force it to meet the more costly requirements of public safety. This paper analyzes the viability of a public-private partnership that serves public safety and commercial subscribers from a for-profit provider's perspective. A model is presented that estimates the net present value (NPV) of a wireless network by calculating costs based on the number of cell sites required and revenue based on the projected number of subscribers acquired. The model is applied to both a network that serves only commercial subscribers on 10 MHz of 700 MHz spectrum and a public-private partnership that serves commercial subscribers and public safety personnel on 20 MHz of 700 MHz spectrum. It is found that NPV is greater for the public-private partnership than for the commercial-only network for any population density, which shows that the value of 10 MHz of spectrum exceeds the cost of meeting public safety requirements. Furthermore, the paper demonstrates that NPV/cell increases with population density, so urban areas are profitable and rural areas are unprofitable. The paper demonstrates that a partnership covering 94% of the US population breaks even because the most urban 56% of population subsidizes coverage for the next 38%. If initial deployment is subsidized, a financially sustainable public-private partnership can serve much more than 94%. Additionally, it is shown that allowing urban municipalities to opt-out of the partnership can significantly increase the subsidies required. 相似文献
78.
Pietro Crocioni 《Telecommunications Policy》2011,35(1):1-11
Net Neutrality has become the focus of attention in the regulatory debate on the Internet. This article attempts to strip down the debate to its bare essential. It identifies two main types of Net Neutrality obligations that have been put forward and assesses what type of potential concerns they may be designed to address. It concludes that while some of these concerns may be important it remains doubtful (at least in Europe) that an ex ante per se rule, such as those proposed under the Net Neutrality term, is the best way to address them. 相似文献
79.
Peering points between different Internet service providers (ISPs) are among the bottlenecks of the Internet. Multihoming (MH) and content delivery networks (CDNs) are two technical solutions to bypass peering points and to improve the quality of data delivery. So far, however, there is no research that analyzes the economic effects of MH and CDNs on the market for Internet connectivity. This paper develops a static market model with locked-in end users and paid content. It shows that MH and CDNs create the possibility for terminating ISPs to engage in monopolistic pricing towards content providers, leading to a shift of rents from end users and content providers to ISPs. Implications for future innovations are discussed. 相似文献
80.
净现值、内部收益率、获利指数等贴现指标在互斥项目选择的实际应用中,常导致不同的投资决策,其原因、解决方法是本文探讨的目的。文章首先对净现值和内部收益率进行比较分析,着重介绍了内部收益率的先天缺陷及替代方法MIRR;然后分析净现值和获利指数的主要差异,最后得出结论:净现值是确定条件下投资项目评价标准中最合理的方法,其他标准则需结合着净现值来运用,否则可能导致决策失误。 相似文献