Understanding the relationships between private automobile availability, overall physical activity, and travel behavior in adults

In most developed countries motorized transportation is the dominant form of travel for long and short journeys. Transport-related physical activity (TPA), however, is advocated as an appropriate transport mode for traveling short distances. The purpose of this study is to explore the associations between private automobile availability, overall physical activity levels, and TPA engagement in the adult population. A population-representative telephone survey assessed socio-demographics, private automobile availability, overall physical activity levels, and travel to place of work/study and the convenience shop with an adult sample (n = 2,000) residing in North Shore City, Auckland, New Zealand in April 2005. The majority of respondents reported unrestricted (80%) or frequent (12%) private automobile availability. After controlling for covariates, binary logistic regression analyses revealed those with no private automobile available were less likely to be classified as sufficiently active for health benefits when compared to respondents with unrestricted private automobile availability. However, this finding was based on a small minority (4%). Also, those reporting no private automobile availability were more likely to walk or cycle to place of employment and the convenience shop when compared to those with unrestricted private automobile availability. Similar to other self-report travel and physical activity survey tools, the questionnaire used potentially did not adequately capture TPA engagement. Future TPA research needs to incorporate objective measures to address this issue.

宣大高速公路水泥混凝土路面使用性能评价

结合宣大（宣化-大同）高速公路改建项目分析水泥混凝土路面使用性能评价原则、指标及方法。采用人工方法调查路面的损坏状况,车载式激光平整度仪测定路面平整度,摆式仪测定路面的摩擦系数,得出路面损坏状况指数PCI、路面行驶质量指数RQI、路面抗滑性能指数SRI,进而得到路面使用性能指数PQI;并采用落锤式弯沉仪测定路面弯沉值,得到路面结构强度指数PSSI。综合评定宣大高速公路现有路面使用性能,并提出相应的处治方案。     

高职院校体育课实施素质教育的途径和方法

本文采用理论与实践相结合的研究方法,在系统分析素质教育涵义和高职学校体育在素质教育中的作用的基础上,提出了高职学校体育实施素质教育的途径和方法：贯彻落实科学发展观,坚持以人为本,从学生实际开展体育教学;更新学校体育教育思想观念,把健康教育作为学校体育的重要任务;加强师德建设,不断提高体育教师的综合素质;重视学生体育学科能力的培养;调整课程结构,更新教学内容,改革教学方法;建立健全科学的体育教学评价体系,全面提高学生的整体素质。     

城市公共交通一卡多用系统经济评价研究

为了对城市公共交通一卡多用系统拟建项目的财务可行性和经济合理性进行分析论证,为项目的科学决策提供依据,本丈对城市公共交通一卡多用系统的经济评价基础进行了研究。首先以随机效用理论建立了一卡多用系统业务量预测模型,对系统成本和效益进行了详细的分析,然后讨论了系统的经济评价指标,并提出不同应用环境中评价指标的确定和选取方法,为项目的科学决策提供了坚实的理论基础。     

长期光氧老化对沥青性能的影响

通过室内模拟长期光氧老化试验,对沥青的组分、物理性能及结构进行了分析,研究了沥青的老化机理.     

Sediment physical properties of the DYNAS study area

Physical properties of the deposits in the DYNAS study area, the Mecklenburg Bay, were investigated using sediment echosounders and laboratory analysis were carried out on undisturbed short sediment cores. Wet bulk densities of about 1.2 g/cm³ for mud and up to 1.9 g/cm³ for silty sand were found in surface sediments of the Mecklenburg Bay. Sediment density–depth functions were approximated by logarithmic regression functions at different depth intervals. Sediment consolidation was studied by both (i) consolidation tests of sediment samples and (ii) from the void ratio–overburden pressure relation in natural sediments. Low shear strength values of 9–71 Pa were measured at the mud surface. Downcore, a depth gradient of about 14.5 Pa/cm was calculated. Sediments with high silt and sand contents are characterized by shear strength values of up to 3000 Pa. Published formulas derived from erosion studies were used to calculate the critical shear stress using wet bulk density and shear strength. The obtained results demonstrate clearly, that there is still a wide gap in knowledge about the relationships between erosion parameters and sediment physical properties.     

透水砼结构特点及其透水性能研究

就功能而言,透水砼与普通砼相比较,最大的区别就是其良好的透水性能.本文分析了透水砼的结构特点、透水指标及其影响因素,通过试验确定了透水砼的透水系数,建立了透水性能与孔隙率、透水系数与力学强度之间的关系,目的是为透水砼配合比设计提供参考依据并指导透水砼路面的结构设计.     

桥梁工程设计集成化CAD技术工作设想的探讨

基于种种现有桥梁CAD系统的不足之处,目前,人们已不能满足于单纯以辅助绘图或单纯以辅助分析为目标的CAD系统,更期望CAD系统能辅助整个桥梁设计过程。在分析桥梁工程设计问题的特点和桥梁工程设计方法的基础上,探讨桥梁设计集成化CAD技术。     

城市轨道交通设施设备故障综合评估预警方法

通过分析城市轨道交通设施设备故障综合评估预警需求,建立一套从单因素预警指标、设施设备综合子系统到线路综合系统的三级综合评估预警指标体系.在此基础上,针对3个层级对轨道交通设施设备进行预警阂值及等级划分,这样有助于提高设施设备的可靠性及安全性水平,从而保障地铁的安全运营.     

武汉地铁保护区安全监控技术研究及应用

随着我国对城市地下空间开发的投资增加,近年来,武汉轨道交通建设也飞速发展,城区轨道交通网络逐步形成,地铁保护区也越来越多,这些区域内多存在在建或规划的大型建设项目,其建设过程可能造成地铁结构变形,增加地铁运营的风险,因此,对地铁保护区内结构进行安全监测受到管理部门和施工部门的重视。依托武汉市长江多级阶地典型的地铁保护区隧道结构变形安全监测项目,详细论述地铁保护区变形安全监测的方案设计、实施及控制指标等因素,并通过对比现场监测和计算机模拟结果,研究各因素在不同地质条件下的影响程度和范围。针对武汉地区的地质特征提出地铁保护区应考虑的主要安全风险因素,为降低武汉地区地铁保护区内的工程风险,保障工程安全建设提供案例参考。