黄河入海悬沙季节输送变化与输送机制的数值研究(英文)

Based on sediment and discharge flux data for the Yellow River, realistic forcing fields and bathymetry of the Bohai Sea, a suspended sediment transport module is driven by a wave-current coupled model to research seasonal variations and mechanisms of suspended load transport to the Bohai Sea. It could be concluded that surface sediment concentration indicates a distinct spatial distribution characteristic that varies seasonally in the Bohai Sea. Sediment concentration is rather high near the Yellow River estuary, seasonal variations of which are controlled by quantity of sediment from the Yellow River, suspended sediment concentration reaches its maximum during summer and fall. Furthermore, sediment concentration decreases rapidly in other seas far from the Yellow River estuary and maintains a very low level in the center of the Bohai Sea, and is dominated by seasonal variations of climatology wind field in the Bohai Sea. Only a small amount of sediments imported from the Yellow River are delivered northwestward to the southern coast of the Bohai Bay. Majority of sediments are transported southeastward to the Laizhou Bay, where sediments are continuously delivered into the center of the Bohai Sea in a northeastward direction, and part of them are transported eastward alongshore through the Bohai Strait. 69% of sediments from the Yellow River are deposited near the river delta, 31% conveyed seaward, within which, 4% exported to the northern Yellow Sea through the Bohai Strait. Wind wave is the most essential contributor to seasonal variations of sediment concentration in the Bohai Sea, and the contribution of tidal currents is also significant in shallow waters when wind speed is low.     

LNG储罐高低承台桩基础抗震性能对比分析

目前全容式LNG储罐基础常采用低承台和高承台桩基2种形式。采用弹性振动理论,并考虑壳液耦联振动效应,对全容式储罐高、低承台桩基的抗震性能进行对比分析,给出了2种桩基础形式下全容式LNG储罐结构与基础的震动特性,包括自振周期、单桩水平地震力、抗倾覆性能、罐底周边单位长度上的提离力、储液晃动周期以及晃动波高等。分析表明,高承台桩基的水平地震响应大于低承台8.69%、垂直地震响应大于6.34%;低承台桩基的抗倾覆能力比高承台高12.11%,抗提离能力高于高承台储罐11.42%;高承台的自振周期高于低承台;低承台基础结构的抗震能力要优于高承台基础结构。其结论对桩基础全容式LNG储罐的设计与施工具有一定的参考价值。     

黄河入海泥沙悬移输送机制的控制试验(英文)

Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant-Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.     

国际集装箱海上运输出口运作时间控制探讨

高效、规范的进出口物流服务平台正成为提高我国外贸企业国际竞争力的新渠道,它也推动中国集装箱运输业的快速发展,国际集装箱海上运输出口运作的关键是衔接、控制好各环节的时间.文章论述了发货人在出口运作时间控制方面存在的问题,并针对问题给出具体对策.     

中国区域综合运输效率的测度及其时空演化

以中国31个省（市、自治区）为研究单元,采用DEA模型对1988-2011年中国省域综合运输效率时空演化特征进行了分析,结果发现：中国省域综合运输效率总体水平较低,呈现出东部高而中西部低的空间格局;从分解效率来看,中国省域综合运输技术效率水平较低,规模效率普遍较高,技术效率是影响综合运输效率时空格局变化的主要因素。3/4省份完成了由规模收益递增阶段向规模收益递减阶段的过渡,运输资源要素的投入冗余阻碍了综合运输效率水平提高,调控和优化现有运输资源结构,提高技术效率成为提高综合运输效率的主要途径。     

MSAS基带信号处理关键技术

给出了日本MSAS（多功能卫星增强系统）基带信号处理各项关键技术的算法原理,并对2006年在成都高楼上采集的MSAS卫星信号数据通过软件进行了基带信号处理,验证了各关键技术算法原理的正确性。另外,提出对GPS接收机增加1个MSAS通道以便提高我国GPS卫星导航接收机的定位精度和进一步增强GPS卫星导航完好性监测。     

“一带一路”倡议下中国陆海运输的空间竞合格局

在“一带一路”倡议全面实施的背景下,中欧班列的建设明显提升了中国与欧洲的陆上集装箱运输量,但陆运较之于海运是否具有比较优势以及形成怎样的空间竞合格局,是当前非常值得研究的经济地理课题。采用中欧班列、中国铁路货物运费及海运数据,将不同价值的集装箱在时间成本中产生的利息纳入运费计算,构建陆海运输平衡线与集装箱价值平衡点模型,刻画中国大陆至欧洲的陆海运输空间格局。研究表明：不考虑时间成本时,陆海运输平衡线位于西北地区,考虑时间成本后,平衡线向东南沿海迁移;以通辽—沈阳—北京—石家庄—襄阳—重庆—丽江—保山为界,形成陆运优势片（阿拉山口区、满洲里区和二连浩特区）和海运优势片（环渤海区、长三角区和珠三角区）,构成“两片六区”格局;考虑未来陆路运价可能降低,以南通—南京—南昌—岳阳—贵阳—昆明—普洱为界可以构建“两片五区”新的陆海运输格局。在此基础上,中国大陆至欧洲的集装箱陆海运输竞合格局可进一步划分为面积占比70.9%、12.9%和16.2%的陆运区、海运区及陆海区。研究说明可以通过陆运运价的调整以及货运集散地的优化布局,来获取中国大陆所需要的陆海平衡线分布,从而谋划基于陆海竞合基础上的中欧集装箱运输的最优联动格局。     

水温及密度对皱纹盘鲍(Haliotis discus hannai)幼虫运输存活率和变态率的影响

本研究以皱纹盘鲍3日龄幼虫为实验材料,开展不同运输水体温度和幼虫密度对运输后幼虫存活率和变态率影响的研究。实验采用双因子实验设计,设置3个温度梯度(分别13、16和20℃),每一温度梯度下设置4个幼虫运输密度梯度(分别为50、100、150和200个幼虫/ml),共12个实验处理,每个处理均设置3个重复组;同时研究了高密度幼虫运输条件下水体溶氧的变化。实验结果表明温度因子、密度因子以及两者的交互作用均对皱纹盘鲍幼虫的存活率和附着率有极显著影响(P0.001),且多重比较表明在条件为水温为16℃,密度为150幼虫/ml下,是最适宜皱纹盘鲍幼虫的运输。本实验同时揭示12 h运输时间内皱纹盘鲍3日龄幼虫具备能耐受低氧水体环境能力(溶解氧DO2 mg/L)。本研究为皱纹盘鲍异地采苗、人工养殖提供参考,也在皱纹盘鲍幼虫增殖放流等领域具有应用价值。     

氢的储存与运输

开发氢能还存在一个难题,就是氢气的储存,它直接影响到氢能的应用。怎样用经济可行的方法将氢约束,为人类服务,下面简述几种储存氢的方法。     

隧道掘进机施工技术

【内容简介】本书共分10章,全面系统地介绍了各类隧道掘进机的基本原理及特点、盾构分类及选型、盾构法隧道施工技术和要点。对土压平衡盾构施工技术、泥水盾构施工技术、硬岩隧道及盾构法隧道的运输技术进行了详细介绍,特别是结合具体工程实例,阐述了复合盾构在复杂地层中施工和大直径盾构在软土地区进行盾构法隧道施工的最新技术和进展。书中论述的隧道施工技术,基本代表了中国当今最新的盾构法隧道的施工水平。文中给出的实例均为隧道工程施工经验总结,条理清楚,数据齐全,针对具体工程实例给出了详细分析,对隧道工程设计、施工和管理都有较大的借鉴价值。