高速公路长隧道出口段照明优化研究

本文在对出口段的环境特征和交通事故分布特征等方面进行分析的基础上,确定视觉适应时间等照明优化参数,提出优化方案,给隧道照明提供了理论借鉴。     

结合工程实例探讨隧道施工通风方案的选择

随着国家交通建设的大力发展,工程建设中隧道工程越来越多,特别是长、大隧道层出不穷。针对隧道工程施工过程中,依靠机械通风来保证洞内空气质量,在现场实际施工过程中,存在通风系统配置不合理,通风效果不尽人意的地方。并且在实施性施组中,通风系统设计普遍存在笼统、针对性差,指导意义不强的现象,本文结合实际,提出合理的通风设计风案,与大家进行探讨。     

Drivers and projections of vegetation loss in the Pantanal and surrounding ecosystems

Modeling scenarios can help identify drivers of and potential changes in land use, particularly in rapidly changing landscapes such as the tropics. One of the places where most of the recent anthropogenic land use changes have been occurring is the "arc of deforestation" of the Amazon, where several scenarios have been constructed. Such modeling scenarios, however, have been implemented less frequently in wetland areas, but these are also undergoing rapid change. An example is the Pantanal, one of the largest wetlands on the planet located in the Upper Paraguay River Basin (UPRB). The UPRB is formed by the lowland (Pantanal) and the plateau (Cerrado and Amazon where the spring-fed rivers are). We used a spatially explicit model to identify drivers of vegetation loss in the Pantanal and surrounding area (UPRB) and estimated potential vegetation loss for the next 30 years. The model is probabilistic and considers that vegetation loss is contagious, so that the local rate of deforestation increases over time if adjacent sites are deforested, also taking into account the drivers identified in those locations. Our study is the first to simulate vegetation loss at property-scale, over 20,000 properties, for the entire UPRB in Brazil, taking into account the relationship between the plateau, where headwaters are located, and the lowland, where flooded-areas are concentrated. The drivers of vegetation loss identified for the lowland (distance to roads and rivers and elevation) differed from those for the plateau (distance to cities), demonstrating the relevance of analyzing areas separately. The cumulative rate of native vegetation loss projected for 2050 was 3% for the lowland and 10% for the plateau, representing losses of 6045 km² and of native vegetation area decreasing from 87% to 83% and 7960 km² from 39% to 35% respectively by 2050, if changes continue at the same pace and if the environmental legislation is followed. The projected vegetation loss in the UPRB forms a geographical arc, very similar to that observed in the Amazon, from the plateau into the lowland. The arc is directly related to areas with no or low flooding frequency because they are suitable for agriculture. The identification of this arc of vegetation loss calls for urgent conservation policies for this wetland and new perspectives for management.     

做大做强港口经济是湖北省长江经济带加速发展的重要途径

本文阐述了湖北发展港口经济的意义和影响,分析了当前湖北省发展港口经济的优越条件和面临的问题,并在国内其他地区内河临港经济发展经验的基础上提出了湖北长江经济带港口经济发展的措施。     

长三角地区生产性服务业发展的主导因子比较

借鉴产业生态因子相关理论，使用逐步回归分析方法,比较了影响长三角地区生产性服务业发展的主导因子，得出结论：影响江苏生产性服务业发展的主导因子是消费结构，而浙江是总体经济发展速度，上海是产业结构生态因子，并提出了相应的政策建议。     

浅析高铁隧道的拱顶脱空防治技术

高铁隧道拱顶脱空是隧道工程施工常见的质量缺陷,如何有效控制拱顶脱空成为控制隧道施工质量的关键。通过深入分析初期支护、防水板和二次衬砌的拱顶背后脱空原因,提出了针对性的防治措施,取得了良好的社会和经济效益。     

技术创新与长江经济带产业结构升级——市场化的调节作用

技术创新是推动产业结构转型升级的内在驱动力。基于2007-2017年长江经济带地级市面板数据，采用面板Tobit回归方法与门限效应分析方法，考察市场化调节作用下区域技术创新对产业结构升级的影响机制。结果表明，区域技术创新能有效推动产业结构“两化”发展，在引入市场化的调节作用后这种推动力变强且更为显著，进一步研究发现这种调节作用在产业结构合理化中还表现出门限效应。在分区域分析中，这种调节作用在上游以及中游城市相对较强，在下游城市则相对较弱。最后提出，应注重区域发展异质性，构建最优市场环境，发挥区域创新对产业结构转型升级的推动作用。     

灌浆式预应力混凝土衬砌在高压水工隧洞中的应用

文章通过对工程实例及已建工程的分析,认为在满足条件的高压水工隧洞中,采用限裂灌浆式预应力混凝土村砌结构是合理的、经济的。     

缅甸Tha-htay水电站导流洞施工

缅甸Tha-htay水电站导流洞工程由中国葛洲坝集团公司和广西电力工业勘察设计研究院承包。该电站位于热带雨林地区，导流洞断面大，沿线地质构造较复杂，褶皱和断层发育。文章主要介绍了缅甸Tha—htay水电站导流洞施工的开挖及支护工艺。     

在水冲口隧道施工中进行工艺创新

文章结合山岭公路隧道施工的具体实践，对施工当中遇到的现实问题，提出了具体的解决方法，并通过实践检验方案的可行性和可靠性。