旅游业乘数研究辨正

乘数效应是研究旅游业经济影响中广泛使用的一种方法.但"旅游业乘数"是一个伪命题,现有的模型、计算方法是不可靠的,广泛引用的数据也不可信.本文分析了旅游业乘数研究的不足,并提出了几点建议.     

社会流动对村庄信任模式的冲击

在社会化条件下的传统型中国乡村,生产、生活、乃至交往都被卷入了一个开放、流动、分工的社会化体系之中,以往那个封闭、保守、内敛的传统乡村社会中的乡村信任模式在新的社会环境下受到了不可避免的冲击与影响。本文从社会流动对于传统村庄信任模式的冲击的角度思考在社会转型期条件下构建村庄信任模式的理性道路。     

国际大宗初级产品价格波动对中国的影响

文章通过分析以美元计价的铁矿石和原油等大宗初级产品价格波动的特征和原因,研究了初级产品价格波动对中国的影响机制和渠道,同时提出了应对初级产品价格波动的对策。     

Tourist accommodation,consumption and platforms

The expansion of mediated accommodation on peer to peer (P2P) platforms, such as Airbnb, has generated extensive economic impact and structural changes in all the destinations involved. This study proposes an innovative analysis which estimates the economic impact associated with the expenditure of tourists staying in traditional hotel establishments in comparison to the impact of those staying in tourist housing mediated through P2P platforms. This research analyses fieldwork based on 1343 surveys carried out in the city of Granada, one of the main tourist destinations in Spain. Through the application of the input–output methodology we found that tourists staying in tourist housing mediated through P2P platforms generate a greater impact as a consequence of longer average stays and more heterogeneously distributed consumption. Their average expenditure is similar to that of tourists in hotels, but the indirect impact generated is greater. Consequently, we can better comprehend the economic impact associated with these platforms and their real effect. Public planners have to consider this information as part of the regulation and restriction of this activity.     

市域协同创新水平动态评价及可视化分析

相较于省域协同创新水平评价,市域层面动态评价结果更能展现区域发展特征,可视化分析能更好地反映出地区差异。基于协同创新基础、协同创新合作和协同创新产出3个维度,构建市域协同创新水平动态评价及可视化分析模型,从静态和动态角度进行整体及分项评价分析。结果表明,江苏省市域协同创新水平差异显著,存在“南高北低,两极分化”现象;南京得益于其丰富的政治、经济、教育资源,协同创新水平最高;苏州居苏南最高,经济环境和沪宁辐射推动其协同创新发展;徐州赶超部分苏南城市,与其区位优势和教育资源密不可分。将时间因素纳入动态评价方法,并采取多种可视化方式呈现结果,提高差异辨析速度和效率。     

资源稀缺、技术冲击与风险投资退出时机

本文从风险投资市场资源稀缺的特征出发,建立了一个风险投资退出时机选择模型,在此基础上,运用2004-2011年中国风险投资退出的季度数据考察了技术冲击和市场利率等因素变化对风险投资退出时机的影响。研究发现：（1）资源稀缺的程度与风险投资退出时机的选择有着非常紧密的联系;（2）市场利率的变化对风险投资的退出行为的影响具有不对称性：市场利率下降可能会导致风险投资加速退出质量较差的风险企业,同时却更长时间地持有质量较好的风险企业;（3）技术进步会增加风险企业的数量,提高风险投资市场上风险企业的平均质量,加速风险投资退出。     

面向全球人工智能高影响力科研人员的综合学术影响力评价模型研究

科技人才对于一国的科技创新发展至关重要,科学合理地评价科研人员的学术影响力,对于科技人才遴选、引进、管理具有重要意义,同时,也可以营造公平、公正的学术氛围,推动科技发展。本研究针对新兴科技领域知识迭代更新快的特点,提出了新兴科技领域科研人员学术影响力综合评价体系和模型,并以人工智能高影响力科研人员为例进行了分析。结果发现,成果引用情况对学术影响力影响最大,其次是学术研究能力和学术活跃程度。本研究提供了一种指标客观赋值的方法,对于科研人员学术影响力的客观评价提供支撑。     

Using technology to improve the management of development impacts on biodiversity

The mitigation hierarchy (MH) is a prominent tool to help businesses achieve no net loss or net gain outcomes for biodiversity. Technological innovations offer benefits for business biodiversity management, yet the range and continued evolution of technologies creates a complex landscape that can be difficult to navigate. Using literature review, online surveys, and semi-structured interviews, we assess technologies that can improve application of the MH. We identify six categories (mobile survey, fixed survey, remote sensing, blockchain, data analysis, and enabling technologies) with high feasibility and/or relevance to (i) aid direct implementation of mitigation measures and (ii) enhance biodiversity surveys and monitoring, which feed into the design of interventions including avoidance and minimization measures. At the interface between development and biodiversity impacts, opportunities lie in businesses investing in technologies, capitalizing on synergies between technology groups, collaborating with conservation organizations to enhance institutional capacity, and developing practical solutions suited for widespread use.     

Impact Fees and Real Estate Prices: Evidence from 35 Chinese Cities

Local governments often charge developers impact fees to finance local public goods. This has been practiced in Chinese cities for more than two decades; however, no empirical studies have tested the effect of impact fees on real estate prices. Using a panel data set for 35 large- and medium-sized cities from 1998 to 2008, we find that impact fees lead to a significant increase in real estate prices. For a given city, an increase in impact fees by one yuan leads to an increase of about 5 yuan in the price of newly-built housing; a 1% increase in impact fees leads to an increase of 5 percentage points in the housing price index and 7 percentage points in the land price index.     

汽轮机低压缸振动的原因分析

文章对汽轮电机组运行时低压缸不定期出现振动和冲击的现象进行分析,查找原因,并提出处理方法。