矿区铁路钢筋混凝土桥梁裂缝成因及整治

平顶山矿区铁路线上有几十座钢筋混凝土桥梁，在使用过程中由于多种原因产生了各种裂缝，通过不同整治方法处理后，延长了桥梁的使用寿命，提高了桥梁的承载力。     

桥梁病害对桥梁设计的启示分析

现阶段,随着社会经济的飞速发展,道路基础设施的建设速度逐渐加快。同时,随着各种各样桥梁病害问题的出现,对桥梁的承载能力造成了一定程度的影响。因此,及时防治桥梁病害有助于保障桥梁的安全性。论文结合某危桥改造项目,对桥梁的病害展开研讨,对病害的产生原因进行分析,并提供实用性的桥梁设计应对方法,以保证桥梁的耐久性与安全性。     

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation

Use of biofuels diminishes fossil fuelcombustion thereby also reducing net greenhousegas emissions. However, subsidies are neededto make agricultural biofuel productioneconomically feasible. To explore the economicpotential of biofuels in a greenhouse gasmitigation market, we incorporate data onproduction and biofuel processing for thedesignated energy crops switchgrass, hybridpoplar, and willow in an U.S. AgriculturalSector Model along with data on traditionalcrop-livestock production and processing, andafforestation of cropland. Net emissioncoefficients on all included agriculturalpractices are estimated through crop growthsimulation models or taken from the literature. Potential emission mitigation policies ormarkets are simulated via hypothetical carbonprices. At each carbon price level, theAgricultural Sector Model computes the newmarket equilibrium, revealing agriculturalcommodity prices, regionally specificproduction, input use, and welfare levels,environmental impacts, and adoption ofalternative management practices such asbiofuel production. Results indicate no rolefor biofuels below carbon prices of $40 perton of carbon equivalent. At these incentivelevels, emission reductions via reduced soiltillage and afforestation are more costefficient. For carbon prices above $70,biofuels dominate all other agriculturalmitigation strategies.     

亚洲石油大陆桥建设设想

本文提出了关于建设亚洲石油大陆桥设想的国际意义,以及我国参与建设的必要性,并构建了亚州石油大陆桥的基本框架,最后提出中国应采取的主要对策和措施.     

港澳珠大桥的方案选择与财务可行性分析

首先介绍了港澳珠大桥的主要方案及分歧所在,然后从区域经济角度进行客货量预测,根据客货量预测和区域基础设施的发展规划,探讨大桥的功能定位并选择最佳方案——中线方案,最后根据客货量预测探讨了大桥的财务可行性,得出结论,港澳珠大桥财务可行。     

Could the Faustmann model have an interior minimum solution?

The growth of an even-aged stand usually follows a S-shaped pattern, implying that the growth function is convex when stand age is low and concave when stand age is high. Given such a growth function, the Faustmann model could in theory have multiple optima and hence an interior local minimum solution. To ensure that the rotation age at which the first derivative of the land expectation value equals zero is a maximum, it is often assumed that the growth function is concave in stand age. Yet there is no convincing argument for excluding the possibility of conducting the final harvest before the growth function changes to concave. We argue that under normal circumstances the Faustmann model does not have any interior minimum. It is neither necessary nor proper to assume that the growth function is concave in the vicinity of the optimal rotation age. When the interest rate is high, the optimal rotation may lie in the interval on which the growth function is convex, i.e. before volume or value growth culminates.     

大吨位宽幅转体现浇箱梁支架设计与施工

桥梁水平转体施工技术日趋成熟,大跨度、大吨位等技术指标不断突破,转体法施工优势得到充分发挥。本文根据桥梁分段现浇、一次整体转体到位的特点,结合转体法施工工况,论述了软弱地基条件下大吨位宽幅转体现浇梁支架设计与施工技术。     

Official rotation and corporate innovation: Evidence from the governor rotation

Rotation is a practice whereby officials are regularly moved between equally ranked positions. Focusing on governor rotation, this paper examines the effect of official rotation on corporate innovation in China. First, we find that official rotation significantly promotes corporate innovation, including enterprises’ innovation investment, quantity, and quality. Second, we find that the effect of official rotation on corporate innovation varies because of official and regional heterogeneity. Officials rotating from other provinces significantly stimulate corporate innovation, but officials rotating from the central government have an insignificant influence on corporate innovation. In addition, officials rotating to non-eastern regions significantly enhance corporate innovation, while officials rotating to eastern regions have a negligible impact on corporate innovation. We further examine the driving mechanism behind the effect of official rotation on corporate innovation and find that officials rotating from eastern regions to non-eastern regions can significantly promote corporate innovation, but officials rotating from non-eastern regions to eastern regions do not boost corporate innovation. These findings imply that the different effects of official rotation on corporate innovation are due to the official experience effect. We also find that official rotation can promote corporate innovation through reducing corporate charitable donations and increasing corporate innovation subsidies. In a supplementary analysis, we find that GDP-oriented performance appraisal pressure weakens the effect of official rotation on corporate innovation. The lower the pressure on officials regarding their performance, the more significant the effect of official rotation on corporate innovation. In addition, official rotation can significantly promote the development of the regional economy and improve the GDP growth rate via corporate innovation, which is a micro-level economic growth effect of official rotation. Overall, our findings further verify the economic effect of official rotation and extend our understanding of the influencing factors of corporate innovation from the perspective of the official governance system. Our findings also have clear policy implications for how the government can improve the official governance model to promote corporate innovation during the transition period of the national innovation system.     

阐述如何加强道路桥梁施工监理

通常,道路桥梁的施工难度较高,其中涵盖的内容较多,如技术管理、预算管理、成本控制等。这些因素使道路桥梁的施工变得更为困难,施工的复杂性和综合性更加突出。在桥梁的施工过程中,存在着许多风险,所以需要做好施工监理工作,从而最大限度地保障施工过程中不会出现任何故障和问题。因此,加强道路桥梁施工监理至关重要。论文从道路桥梁施工的角度,探究和分析如何做好相关的监理工作。     

桥梁路面防水施工技术关键点研究

桥梁工程具有周期长以及范围大等特点。因此,在桥梁施工中任何一个环节出现偏差,都可能诱发裂缝或剥离等问题,最终影响整个桥梁的质量。路面防水工程是桥梁施工项目中的重要环节,防水工程的施工质量将直接影响桥梁结构的整体质量以及使用寿命。因此,在桥梁防水施工过程中,要选择合格的施工材料以及最优的施工方法,从而提高桥梁路面防水工程的施工质量。