浅析GPS测绘新技术在建筑工程项目中的运用

现代化的GPS测绘技术在建筑施工项目当中有着重要的应用,而深入的对应用的范围和层面进行细致的分析,将有助于增强GPS测绘的使用水准。文章将针对这一方面的内容展开论述,详细的分析了GPS测绘在建筑施工项目当中的实践使用情况,同时对GPS测绘的要点和技术的难点、创新点等进行了深入的探讨,旨在全面的增强和促进GPS测绘技术的改进,为GPS测绘技术的发展奠定坚实的基础。     

Does the Connectivity of the Belt and Road Initiative Contribute to the Economic Growth of the Belt and Road Countries?

ABSTRACT

Since the Belt and Road Initiative (BRI) has been implemented for five years, it is time to ask whether the BRI contributes to Belt and Road (BR) countries’ economic growth, and how are the five elements of connectivity implemented between China and its partner countries since the BRI was proposed. This study focuses on the development of the five elements of connectivity between China and the BR countries from 2008 to 2017 using a comprehensive connectivity index extracted from principle component analysis, and then investigating if the connectivity has contributed to the economic growth of the BR countries with quantitative analysis of the fixed effect econometrical model. It is found that Russia, South Korea, and Singapore presented the top three levels of connectivity with China with regard to the overall connectivity index, varying from 1.4 to 2.4. Madagascar and Panama have the lowest level of connectivity with China, with values of ?0.8 to ?1.1. The result of the fixed effect model shows that the connectivity of the BR countries with China contributes to their economic growth. This provides quantitative evidence that the connectivity between BR countries and China has a significant influence on the economic growth of those countries.     

智慧城市建设对城市科技创新能力的影响

基于2008—2018年中国212个地级市面板数据,构建双重差分模型，评估智慧城市建设对城市科技创新能力的政策影响效应，并对城市异质性进行拓展分析。结果显示，智慧城市政策能够显著提高区域科技创新能力，且城市科技创新基础越好，政策效应越突出。据此提出智慧城市建设应从优化科技创新投入结构、共建协同创新平台、完善成果转化机制、优化创新空间布局等多个维度协力打造科技创新生态，整体提升科技创新实力。     

绿色全要素生产率的区域差异与动态演化

文章基于2001-2017年中国大陆30个省份的面板数据,综合运用SBM-DEA模型、dagum基尼系数和马尔科夫链等多种方法,对中国绿色全要素生产率的区域差异与动态演化进行了分析.研究发现:中国绿色全要素生产率整体呈波动上升趋势,存在显著的非均衡特征且随着时间的推移明显加剧;区域间差异与超变密度差异是绿色全要素生产率差异的主要来源;中国区域绿色全要素生产率各种状态间的流动性较高.最后,研究从推进区域一体化战略,加强落后地区的基础设施建设及提高企业的信息化能力等方面提出缩小绿色全要素生产率差异的政策建议.     

City Size,Population Concentration and Productivity: Evidence from China

This paper investigates the impact of China's city size and urban population concentration on city productivity by developing a distinctive index based on global nighttime light data. Using the panel data of 280 prefecture cities from 2004 to 2013 and employing dynamic system generalized method of moments and panel threshold model regression techniques, our results show that city size has a positive impact on city productivity; therefore, cities in China still have the potential to expand. While moderate urban population concentration can benefit city productivity, excessively concentrated urban population distribution may impede the growth of city productivity. We also find that the level of labor income significantly affects the impacts of urban agglomeration on labor productivity. Therefore, our results imply that city development policies should focus more on how to appropriately allocate economic activities and adjust population distribution in urban areas according to different stages of economic development.     

新形势下苗木产业发展的建议

苗木是营林生产的基础。针对新形势下苗木生产产能猛增,需求萎缩,苗木发展政策长期利好的现状,面对劳动力紧张、雇工成本过高,土壤肥力下降,苗木质量降低,育苗生产经营方式发生转变的问题,提出了苗木产业发展必须实施良种化、培育设施化,进行土壤改良和营销网络化的建议。     

六家煤矿北翼运输大巷围岩注浆加固及底板组合锚索

本文介绍了松软岩层在原支护状态被破坏后重新采用注浆及锚网索联合支护维修加固技术的应用方法。