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61.
文章突破了原有的城市土地限制性因素分析,从城市土地经营的行为主体的角度,开创性的提出城市土地集约利用的促进性因素,对城市土地的集约类型进行了划分,划分为了主动性土地集约和受动性土地集约,进而细分为内生性主动集约和外生性主动集约、相权性受动集约和调控性受动集约。并将这些因素置于私人收益、私人成本、社会收益、社会成本的复合坐标体系之下作了进一步的区分与研究,分别对其形成的原因和表现作了进一步的阐释和描述,同时对控制土地集约度的重要性子以强调,最后对土地集约促进性因素的分类及其运作做了相关的展望。  相似文献   
62.
面向全球导航卫星系统(Global Navigation Satellite System,GNSS)信号的外辐射源雷达,是一种利用环境中GNSS信号作为非合作照射源进行探测的雷达。为满足基于GNSS信号的外辐射源雷达系统仿真和信号处理算法设计评估的需要,通过对该雷达系统组成与工作原理的分析,完成了面向GNSS信号的外辐射源雷达软件化信号模拟器的设计与实现。给定仿真场景下软件化模拟器输出信号处理和分析的结果验证了该模拟器可根据输入参数与模型正确完成信号仿真。  相似文献   
63.
新冠肺炎疫情严重影响了企业经营活动,但在一定程度上也推动了远程办公这种新型工作方式。为探究该领域研究进展,收集近10年Web of Science(科学引文索引)数据库中收录的“远程办公”或“线上办公”为主题的242篇核心文献,通过文献计量软件CiteSpace分析国外远程办公研究文献间的关联关系,探寻国外远程办公领域的发展脉络和研究前沿。在此基础上,对近10年国内中国知网数据库20篇中文核心文献进行综述,希望为未来国内远程办公的本土化研究提供参考。  相似文献   
64.
被动式传感器目标跟踪是多传感器多目标跟踪领域的一个重要研究方向。针对三被动式传感器多目标定位系统全局最优数据关联的三维分配问题,在允许传感器漏检和虚警的情况下,通过分析拉格朗日松弛算法,提出一种假定真实目标的快速收敛算法。该算法通过粗关联假定真实目标并重新修改代价矩阵,然后进行细关联,使得拉格朗日松弛算法在保证关联精度的前提下有效地提高了收敛速度。理论分析和实验结果表明,该算法提高了数据关联的速度,并在一定程度上提高了关联准确率。  相似文献   
65.
This article analyzes equally weighted strategic asset allocation portfolios in Brazil between 2004 and 2016 and shows that their average returns are not always statistically greater than those of balanced funds, with significance changing in sub-periods. Fixed-income portfolios frequently outperform balanced funds, whose active management underperforms their declared benchmark portfolios. Balanced funds underperformed probably because they deviated from their investment policy. Transaction costs and other rebalancing frequencies do not change the conclusions. Robustness tests indicate that this evidence is valid out-of-the-sample. Investors can mimic balanced-fund policy and possibly do better by means of indexing according to this policy.  相似文献   
66.
There is a steady global trend towards “Data Localization,” laws by which data is required to be maintained and processed within the geographic boundaries of its state of origin. This development has raised concerns about its possible adverse impacts on emerging data-intensive technologies such as Cloud services/E-commerce, Big Data, Artificial Intelligence and the Internet of Things (collectively, the Embedded Infosphere). The inability to reach an international agreement on rules for cross-border data flows may have significant adverse consequences for all future users of the Internet.The basis of Data Localization is grounded in two distinct but inter-related policy models: Data Sovereignty and Trans-Border Data Flows. These two concepts have different origins. “Data Sovereignty” is derived from the historic power of a state of absolute and exclusive control within its geographic borders. Policies behind TBDFs arose in Europe following World War II, primarily motivated by Nazi use of early proto-computers to help round up Jews and others. As they have evolved, TBDF policies have been directed primarily at protecting personal data and privacy.This article first examines the issues of: 1) “Information Sovereignty” and 2) TBDFs. It then describes the arguments for and against “Data Localization,” offers some examples of strong localization policies (Russia, China), and summarizes contesting policy proposals. It then contextualizes TBDF with issues of human rights (free flow of information) and privacy.While the utility of an international agreement on TBDFs is clear, the differences in approaches are tenacious. For the free-market developed world (e.g, EU, OECD), the path forward seems to lead through policy convergence to compatible rules, with differentiated levels of data protection and accountability. It is far from clear whether these rules will address, in a mandatory way, issues of the “free flow” of information in the human rights sense. At the same time, there are countries (e.g., BRICS), representing a majority of the world's population, in which political and cultural resistance will produce stringent Cyber Sovereignty and Data Localization policies with few if any human rights components.The article concludes that the more the Internet is “localized”, the more attenuated its benefits will become. The negative consequences of Data Localization will become increasingly obvious as new, data-intensive technologies become ubiquitous, creating a condition of “Data Dependence”. It is projected that in the future the nations with the least amount of Data Localization and the most open flow of information will be the most successful in benefiting from new data-intensive embedded, networked technologies. This will most likely be characterized by values adopted as policies and practices in the EU.  相似文献   
67.
This paper argues that the commonly used market indices imply forms of active investment management in disguise. The selection and rebalancing rules make these indices highly exclusive and dynamic regarding their underlying components and significantly bias their performance. Any passive investment tracking these indices turns into an active strategy characterised by market timing and state‐dependent performance. Evidence is provided that exclusive indices outperform (underperform) more inclusive peer indices in upward (downward) markets. The constitution and maintenance rules of exclusive indices correspond to a set of active trading and investment rules similar to momentum strategies.  相似文献   
68.
自第一座军用堆的建成到2019年7月三代核电机组再次获批建设,我国核电经历了长期的发展,进入了核电重启时期。主要简述了不同发展阶段的核电技术路线,核电设备国产化率,以及相关的发展规划。我国核电产业的发展,是核电产业和制造业的奋斗史。核电设备的国产化率在有限的核电项目中不断提高。面对核电国产化过程中遇到的技术难点,我国核电从设计院到制造商共同承担风险,突破困境,实现了三代技术的国产化。在更先进的核电技术需求背景下,核电产业需要建立可持续发展的先进产业设备制造供应管体系。  相似文献   
69.
针对战场级的复杂电磁环境仿真过程中涉及到全频段覆盖、环境影响、仿真速度要求高等问题,提出了一种综合考虑用频装备、环境信息和模型自身特点的电波传播模型选择方法。该方法首先通过频段对用频装备及电波传播模型进行划分,再结合环境信息中降雨量、海拔、植被覆盖率、气候类型、导电特性等参数进行综合分析,最终得到传播模型的优化选择方案。在典型作战场景仿真应用中,该方法为传播模型的合理选择提供了思路,保证了仿真的精度,同时也为电磁环境仿真中传播模型本地化提供了依据。  相似文献   
70.
常嵘 《济南金融》2009,(11):21-24
货币供应量是我国货币政策的中介目标,影响货币供应量的一个关键变量是利率。一般来讲,利率与一国的货币供应量为反相关关系,但这一关系在我国基础货币被动投放的情况下需要重新考量。鉴于我国处在利率市场化的过渡时期,管制利率与正在培养中的市场基准利率Shibor并存,应该通过Shibor作为中间变量来分析央行调控管制利率对货币供应量的影响。  相似文献   
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