Distribution of suspended sediment in the coastal sea off the Ganges–Brahmaputra River mouth: observation from TM data

Remote sensing technique was applied to estimate suspended sediment concentration (SSC) and to understand transportation, distribution and deposition of suspended sediment in the estuary and throughout the coastal sea, off the Ganges–Brahmaputra River mouth. During low river discharge period, zone of turbidity maximum is inferred in the estuary near the shore. SSC map shows that maximum SSC reaches 1050 mg/l in this period. Magnitude of SSC is mainly owing to resuspension of the bottom surface sediments induced by tidal currents flowing over shallow water depths. The influence of depth on resuspension is farther revealed from the distribution and magnitude of SSC along the head of Swatch of No Ground (SNG) submarine canyon. During high river discharge period, huge river outflow pushed the salt wedge and flashes away the suspended sediments in the coastal sea off the river mouth. Zone of turbidity maximum is inferred in the coastal water approximately within 5–10 m depth of water, where the maximum SSC reaches 1700 mg/l. In this period, huge fluvial input of the suspended sediments including the resuspended bottom sediments and the particles remaining in suspension for longer period of time since their initial entry control mainly the magnitude of SSC. In the estuary near the shore, seasonal variation in the magnitude of SSC is not evident. In the coastal sea (>5 m water depth), seasonal influence in the magnitude of SSC could be concluded from the discrepancy between SSC values of two different seasons. Transportation and deposition of suspended sediments also experiences seasonal variations. At present, suspended sediments are being accumulated on the shallow shelf (between 5 and 10 m water depth) in low discharge period and on the mid-shelf (between 10 and 75 m water depth) during high discharge period. An empirical (exponential) relationship was found between gradual settle down of suspended sediments in the coastal sea and its lateral distance from the turbidity maximum.     

使用PHOTOSHOP进行卫星影像光谱增强的方法和优势

利用TM、SPOT、ALOS卫星数据制作不同比例尺真彩色影像的关键步骤在于获得色彩柔和、反差适中的底图.而在遥感信息软件平台(如ERDAS)以及地理信息软件平台(如ARCGIS)上对单幅卫星数据进行细微的、局部的光谱增强往往捉襟见肘.使用PHOTOSHOP这一大众化软件进行卫星影像光谱增强方便快捷,且容易掌握.研究使用该工具进行光谱增强的一般规律及优势,通过探讨得出大面积卫星影像快速解译的普遍方法.     

TM1型机车齿轮箱铸件工艺特点分析

通过对TM1型机车转向架齿轮箱铸件结构及其特性的分析,确定了齿轮箱铸造生产过程中,从材料选择到造型、熔炼、浇注等工序的一系列铸造工艺参数,达到成功生产出口铸件的质量要求。     

TM2型机车空气制动系统

介绍了TM2型机车的风源系统、控制管路系统、辅助管路系统和制动机系统,并对制动机控制电路原理作了详细说明。     

门径管理流程在汽车空调新产品开发中的应用

门径管理流程为企业提供标准化、系统化的项目管理方法。本文在分析国内汽车零部件新产品开发特征及所面临问题的基础上,介绍门径管理方法与形式;并结合国内汽车空调企业新产品开发的实际状况,构建汽车空调新产品开发的门径管理流程。     

基于TDS642EVM的交通参数检测

介绍了一种将DSP应用于交通参数检测的视频监控系统。系统采用TI公司的DSP处理芯片TM320DM642作为处理器,配合FPGA,视频解码芯片SAA7115H、编码芯片SAA7115,共同来完成对各种交通参数的采集,以及实时车道现场视频数据的远程获取。基于TMS320DM642芯片设计的评估开发板TDS642EVM,给出了处理器TM320DM642的编程方案,在PC上利用Visual C＋＋进行界面设计,对DSP发送的数据进行分析处理与显示,并显示出交通参数的检测结果。     

TM3型机车司机室降噪设计

文章简要分析了TM3型电力机车司机室噪声的主要来源,重点介绍了为降低TM3型机车司机室噪声而采取的措施。     

一种沥青路面预防性养护的好方法--表面涂涮沥再生

道路养护技术可分为修补性养护和预防性养护 2种。本文介绍了一种新型的沥青路面预防性养护的好方法——表面涂涮沥再生 Rejuva Seal TM,并以工程实例对涂涮前后沥青路面 3大指标进行了对比、分析     

基于TM影像自动获取冲洪积扇信息模型研究

研究目的:冲洪积扇在遥感影像上有其特有的色调、纹理和亮度等遥感特征,由于冲洪积扇区多是松软土分布区,是影响工程的重要因素之一,利用遥感影像确定冲洪积扇分布范围,用以指导工程选址,是遥感解译工作的重要组成部分。传统的冲洪积扇遥感解译以目视解译为主,其速度慢、周期长,工作量大,难以满足当前铁路、公路高速发展的需求。通过分析研究冲洪积扇的地形地貌和遥感影像特征,基于TM影像,建立冲洪积扇信息提取模型,实现利用算法从影像上自动快速提取冲洪积扇的方法,成果快速地用于指导工程地质选线工作。研究结论:基于冲洪积扇的遥感机理,构建的集冲洪积扇指数、植被指数、湿度指数和地形数据为一体的冲洪积扇信息遥感自动提取模型,能快速、有效地提取TM影像中的冲洪积扇信息,实现了冲洪积扇遥感解译的自动化。     

聚合物脊型光波导的有限元分析

利用有限元法分析了聚合物脊型光波导的基模及高阶模的色散特性和横向场分布,研究了芯层厚度、脊高和脊宽等结构参数对色散特性的影响,计算结果表明,在芯层厚度小于1.3μm、脊宽小于5μm、脊高小于0.2μm时,波导将形成单模传输。