河流峡谷地段地质选线方案研究

研究目的：河流峡谷地段，不良地质极为发育，规模大，又为地下水的排泄区，发育区域性暗河；线路设计同时受技术标准、投资影响；控制选线的因素极为复杂。本文以渝怀线乌江峡谷地质选线研究为例，对经受施工、运营、汶川地震检验，证明合理的地质选线的经验、成果进行研究、归纳、总结，指导类似河流峡谷地段铁路勘察设计工作。研究结论：先期进行河流左、右岸地质选线；峡谷段不良地质极发育，线路方案受地质条件控制，有条件时，线路内移避开沿岸不良地质；线路绕避不良地质困难或代价极高时，只要地质探明，工程措施到位，线路完全可以通过不良地质；根据岩溶发育规律及暗河标高，宏观指导选线，线路最好尽量选择通过岩溶发育安全带。     

拉日线色麦至大竹卡峡谷地段地质选线研究

研究目的:通过对本段地形、地质条件的分析,确定线路方案的选线原则,从而为线路方案的选择和完善提供依据.研究结果:从拉日线色麦至大竹卡段地质选线来看,具有典型的高原山区河谷铁路地质选线的特点.由于独特的自然地理环境和气候特征,使线路方案具有特殊的考虑因素,我们通过分析研究,选出了一条安全、合理、经济的线路方案,为国家节省了大量的资金.     

高职学生英语口语策略使用调查

文中报告了对广州民航职业技术学院一年级三个专业238名学生的口语学习策略使用情况的调查。调查结果显示，学生英语口语学习策略的总体使用频率偏中上，其中补偿策略、记忆策略和情感策略使用频率较高；善学者与不善学者在各项策略使用方面存在显著性差异；男生与女生在口语补偿策略的使用上有显著性差异。     

Error quantification of a high resolution coupled hydrodynamic-ecosystem coastal-ocean model: Part3, validation with Continuous Plankton Recorder data

Data collected during the Continuous Plankton Recorder (CPR) survey has been used to validate a three-dimensional hydrodynamic ecosystem model simulation of the North-west European Shelf for the years 1988–89. The CPR time series is unique to the North Atlantic region as a validation tool. Data were extracted from the model to correspond with those collected by the CPR survey, and both the model and survey plankton data were standardised to allow the comparison of model biomass with survey counts. Simple linear regression and absolute error maps provide a qualitative evaluation of spatio-temporal model performance of simulated diatoms, flagellates, total phytoplankton and omnivorous mesozooplankton. Comparisons of z-scores indicate that the model reproduces the main pelagic seasonal features, and there is good correlation between magnitudes of these features with respect to standard deviations from a long-term mean. The model is replicating up to 62% of the mesozooplankton seasonality across the domain, with variable results for the phytoplankton. There are, however, differences in the timing of patterns in plankton seasonality. The validation exercise has highlighted that the spring diatom bloom in the model is too early, suggesting the need to reparameterise the response of phytoplankton to changing light levels in the model. Errors in the north and west of the domain imply that model turbulence and vertical density structure need to be improved to more accurately capture plankton dynamics.     

Recent sedimentary study of the shelf of the Basque country

The Northern Iberian margin of the Spanish Basque country (provinces of Gipuzkoa and Viscaia) is characterized by a narrow continental platform, which receives inputs of riverine particulate matter from the numerous riverine systems located within the Basque country. This particulate matter is subsequently deposited within the Bay of Biscay, and Gouf de Capbreton [Frouin, R., Fiuza, A.F.G., Ambar, I., Boyd, T.J., 1990. Observations of a poleward surface current off the coasts of Portugal and Spain during winter. Journal of Geophysical Research 95 (C1), 679–691]. The main goal of this study is to establish a map of the surface sediment distribution of the Basque continental shelf and more specifically to map the muddy patch located at the eastern side of that continental shelf.Three oceanographic cruises were conducted in 2003 and 2004. From these campaigns 340 surface samples, 12 short cores and 3 gravity cores have been collected over the mid and outer shelf from depths ranging between 50 m and 150 m deep. 3 seismic profiles were obtained across the shelf mud patch using a Sparker device.Sediment grain-size analyses were performed by the classical physical method of sieving and use of settling columns. The POC (Particular Organic Carbon) amounts in sediment and water samples were determined using the Strickland and Parsons' method [Strickland, J.D.H., Parsons, T.R., 1972. Determination of particulate carbon. In : A practical handbook of seawater analysis. Fisheries ResearchBoard of Canada, Ottawa, pp. 207−211] as adapted by Etcheber [Etcheber, H., 1981. Comparaison des diverses méthodes d'évaluation des teneurs en matières en suspension et en carbone organique particulaire des eaux marines du plateau continental aquitain. Journal de Recherche Océanographique VI (2), 37−42]. Radioisotopic measurements (²¹⁰Pb_exc) were made using a semi-planar germanium detector coupled to a multichannel analyser. Radiographical analysis was performed with an X-ray equipment (SCOPIX®) coupled with a radioscopy instrumentation and processing unit.Firstly, a detailed sedimentological map of this shelf has been produced and secondly, geophysical surveys have precisely mapped the geometry of the main mud patch on the continental shelf. In the mud patch itself the rates of sedimentation are between 0.13 and 0.50 cm yr^− 1. The maximum rate of sedimentation is located in the central mud patch, whereas the minimum rate of deposition occurs close to the rocky outcrops. These results seem to be in agreement with the estimation of the total thickness of the mud patch revealed by seismic profiles. The central part corresponds to the maximum thickness of 7 m.Interpretations of the associated oceanic current forcing factors (current direction, wave fetch and wind directional modes) relating to the identified sediment depositional zones are also undertaken.     

The role of alternative fuel vehicles: Using behavioral and sensor data to model hierarchies in travel

Greater adoption and use of alternative fuel vehicles (AFVs) can be environmentally beneficial and reduce dependence on gasoline. The use of AFVs vis-à-vis conventional gasoline vehicles is not well understood, especially when it comes to travel choices and short-term driving decisions. Using data that contains a sufficiently large number of early AFV adopters (who have overcome obstacles to adoption), this study explores differences in use of AFVs and conventional gasoline vehicles (and hybrid vehicles). The study analyzes large-scale behavioral data integrated with sensor data from global positioning system devices, representing advances in large-scale data analytics. Specifically, it makes sense of data containing 54,043,889 s of speed observations, and 65,652 trips made by 2908 drivers in 5 regions of California. The study answers important research questions about AFV use patterns (e.g., trip frequency and daily vehicle miles traveled) and driving practices. Driving volatility, as one measure of driving practice, is used as a key metric in this study to capture acceleration, and vehicular jerk decisions that exceed certain thresholds during a trip. The results show that AFVs cannot be viewed as monolithic; there are important differences within AFV use, i.e., between plug-in hybrids, battery electric, or compressed natural gas vehicles. Multi-level models are particularly appropriate for analysis, given that the data are nested, i.e., multiple trips are made by different drivers who reside in various regions. Using such models, the study also found that driving volatility varies significantly between trips, driver groups, and regions in California. Some alternative fuel vehicles are associated with calmer driving compared with conventional vehicles. The implications of the results for safety, informed consumer choices and large-scale data analytics are discussed.     

40万吨超大型矿砂船典型结构缺陷

根据第一代40万吨超大型矿砂船(VLOC)的状况勘验情况,对船舶的典型布置和结构特点进行概括,并对船舶的典型结构缺陷进行总结。基于结构特点和运营中的结构受力情况,对典型结构缺陷进行分析。基于分析结果,对典型结构缺陷的处理措施进行介绍。根据现有结构状态,提出结构检验注意要点,为第一代40万吨VLOC的后续结构检验提供指导,也为即将投入运营的第二代40万吨VLOC的结构检验提供参考,以有针对性地对40万吨VLOC进行结构检验,提高结构检验效率。     

层次分析法在盖挖工法选型中的应用研究

盖挖顺作法、盖挖逆作法和盖挖半逆作法这3种工法的选型决策不仅需要考虑工法的可行性,还需要考虑工期、经济性以及社会效益等因素。为了得到3种工法选型决策的评价体系,以青岛五四广场地铁车站为例,运用层次分析法对该地铁车站进行3种工法的选型研究,得到盖挖半逆作法为该地铁车站的最优工法,结果符合实际工程经验;通过对有限元计算结果和现场施工监测结果进行分析,得到盖挖半逆作法表现良好,为最优推荐工法。     

蒙冀界至承德段高速公路细化设计研究

蒙冀界-承德段高速公路主线加支线近200 km,地形复杂,涉及的问题较多。文章针对设计文件对总体设计、路线、路基、路面及防护排水、绿化及景观、工程地质勘察、造价等方面的共性问题进行了细化,确保了设计质量。     

手机数据在交通调查和交通规划中的应用

手机作为一种理想的交通探测器,为居民出行信息分析提供了很好的技术选择。将手机数据映射至交通分析单元,并经信息预处理、匹配分析、交通模型分析处理、数据去噪、扩样等一系列海量数据运算处理,最终可获得居民出行特征数据。利用长期历史手机话单数据,可分析常住人口和就业人口分布、通勤出行特征、大区间OD、特定区域出行特征、流动人口出行特征等。手机信令数据能够较完整地识别手机用户的出行轨迹,可进一步应用于分析城市人口时空动态分布、特定区域客流集散、查核线断面或关键通道客流、轨道交通客流特征、出行时耗、出行距离、出行强度、道路交通状态等。根据天津手机话单数据应用案例及上海手机信令数据应用案例,验证了技术可行性。