Time-series analysis of remote-sensed chlorophyll and environmental factors in the Santa Monica–San Pedro Basin off Southern California

The time-series of remote-sensed surface chlorophyll concentration measured by SeaWiFS radiometer from September 1997 to December 2001 and the relevant hydrological and meteorological factors (remote-sensed sea surface temperature, atmospheric precipitation, air temperature and wind stress) in Santa Monica Bay and adjacent waters off southern California were analyzed using wavelet and cross-correlation statistical methods. All parameters exhibited evident seasonal patterns of variation. Wavelet analysis revealed salient long-term variations most evident in air temperature during El Niño 1997–1998 and in wind stress during La Niña 1998–1999. Short-period (<100 days) variations of remote-sensed chlorophyll biomass were mostly typical to spring seasons. Chlorophyll biomass was significantly correlated with air temperature and wind stress: an increase of chlorophyll biomass followed with 5–6-day time lag an increase of wind stress accompanied by a simultaneous decrease of air temperature. The mechanism of these variations was an intensification of phytoplankton growth resulting from the mixing of water column by wind stress and entrainment of nutrients into the euphotic layer.     

公路工程监理与国际惯例的差距探讨

通过对我国公路工程监理和国际惯例的比较，指出了我国公路工程监理机制与国际惯例的差距，并提出了解决问题的建议。     

空间复合材料加筋板流固耦合振动分析

本文用结构有限元与流体边界元方法研究了空间复合材料加筋板结构的流固耦合自由振动，推导了用于结构分析的分项插值型复合材料八节点板单元和三节点梁单元，以及用于流场分析的线性边界单元。用修正的RIRZ向量法与波前法相结合的方法求解特征值问题，避免了因附连水质量引起的结构质量矩阵为满阵的内存困难和非对称矩阵方程约化困难。算例表明，附连水质量对复合材料结构的动力特性影响要比各向同性材料严重得多。     

高坝枢纽新建通航建筑物轴线及通航条件研究

针对山区已建高坝枢纽新建通航建筑物轴线布置受河道窄、水头高、电站泄流及已有建筑物影响等条件限制的问题,依托贵州清水江白市水电站枢纽新建通航建筑物工程,采用1∶100正态整体水工模型与自航遥控船模相结合的技术手段,对多条轴线布置方案进行通航水流条件及船舶航行操控研究与优化。试验结果表明,右岸轴线布置方案通航水流条件及船舶航行状态均较好,为推荐方案。研究成果解决了工程关键问题,可供类似已建高坝水利枢纽新建或扩建通航建筑物工程参考借鉴。     

境外铁路工程项目建设条件研究

近年来,我国铁路发展所取得的辉煌成就在国际上产生了重大影响,主动提出希望中国铁路参与其国内铁路工程建设的国家越来越多。中国铁路实施"走出去"发展战略,扩大了我国对外影响力和竞争力。此文结合笔者参加巴西、缅甸、哈萨克斯坦等国家铁路工程建设项目的设计研究工作的体会和经验,从相关法律法规、基建程序、资源条件等方面研究承担境外铁路工程建设项目应具备的建设条件。为今后承担境外铁路工程建设提供借鉴。     

轿车前梁有限元分析

利用轿车前梁的CATIA模型建立其有限元模型。通过前悬架的ADAMS模型确定前梁的受力。应用这些方法将CAD、CAE有机的结合在一起，提高了有限元分析的效率和准确性。为了检验模型的精确程度，对前梁进行了静态加载试验。结果表明计算和试验结果有很好的一致性。     

半刚性基层与沥青层之间界面条件对结构性能的影响

利用弹性层状体系理论计算了在不同层间条件下的半刚性沥青路面沥青层中的剪应力、拉应力分布情况及路表弯沉值,分析了基层与沥青层之间由于层间界面条件变化引起的路面结构受力状态的变化。计算表明基层与面层保持连续的界面条件是十分重要的;过分致密不透水的半刚性基层有可能造成路面的早期损坏。     

高职电子信息工程技术专业学生专业能力培养路径的研究与实践

对接电子信息产业人才需求,分析就业岗位工作任务、分解专业能力,在优化课程体系、增强实践教学、完善实践教学支撑体系、培养创新思维和教师队伍建设等方面,形成高职电子信息工程技术专业学生专业能力培养路径,并付之于实践,为电子信息产业培养具有较强专业能力的技术技能人才。     

Are French millenials less car-oriented? Literature review and empirical findings

Generation effects play a key role in shaping long-term trends in travel behaviors. Though cohorts born until the 1970s have been increasingly car-focused, a reversal of this trend was noticed among the millenials. Determining whether this break-in-trend resulted from changes in living conditions and economic difficulties, or demonstrates a shift in attitudes away from the car, is critical to future travel trends. We bring a contribution to this debate in the French context, through a literature review followed by empirical findings, using the French Base of Local Household Travel Surveys. Through age-cohort analysis, we find evidence of changing travel patterns among the millenials, taking the form of a shift from driving to transit, along with a decline of car ownership. However, travel attitudes of the millenials play little role, as they do not differ substantially from their elders. Besides, we show that generation effects disappear once a large number of structural factors are controlled for. It looks like the main driver of change in travel behaviors comes from a shift in residential patterns, in relation with longer studies and a delayed entrance into the workforce, and possibly because of increasing work pressure, degraded transport conditions and changes in residential attitudes and desired lifestyles. In the end, these assumptions should be further explored, along with complementary research tracks, including the role of economic factors, the effects of learning experience, as well as heterogeneity in travel patterns, in relation with issues of social and spatial equity.