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821.
长江官洲河段位于安徽省内,上起吉阳矶,下至皖河口,为首尾束窄中间放宽的鹅头型分汊河道,全长28.0km。该文根据历年水文泥沙及水下地形图等基础资料,分析了该河段的近期演变情况。通过对洲滩及汊道演变分析,得出结论:目前该河段河势处于相对稳定状态,岸线基本稳定。受上游东流河段河势变化影响,局部河床会发生冲淤变化。  相似文献   
822.
介绍新乡至郑州高速公路过黄河大堤地段地基处理和路基加固方案,以及施工过程中所进行的沉降和应力观测。观测结果表明,高压注浆碎石桩是处理复杂填土路基的一种新型有效方法。  相似文献   
823.
高边坡问题在基础建设的发展过程中不断出现,尤其是泥岩边坡问题。文中通过分析泥岩边坡6种病害坡体结构:顺倾层状结构、反倾层状结构、陡倾层状结构、基座式上软下硬结构、交叉式楔形结构,得出了泥岩边坡在不同坡体结构下可能的破坏方式;最终归纳总结出了5种典型的泥岩边坡破坏模式:风化剥落、楔体破坏、倾倒破坏、滑移-拉裂破坏、牵引式滑动破坏。  相似文献   
824.
This paper documents the efforts to operationalize the conceptual framework of MIcrosimulation Learning-based Approach to TRansit Assignment (MILATRAS) and its component models of departure time and path choices. It presents a large-scale real-world application, namely the multi-modal transit network of Toronto which is operated by the Toronto Transit Commission (TTC). This large-scale network is represented by over 500 branches with more than 10,000 stops. About 332,000 passenger-agents are modelled to represent the demand for the TTC in the AM peak period. A learning-based departure time and path choice model was adopted using the concept of mental models for the modelling of the transit assignment problem. The choice model parameters were calibrated such that the entropy of the simulated route loads was optimized with reference to the observed route loads, and validated with individual choices. A Parallel Genetic Algorithm engine was used for the parameter calibration process. The modelled route loads, based on the calibrated parameters, greatly approximate the distribution underlying the observed loads. 75% of the exact sequence of transfer point choices were correctly predicted by the off-stop/on-stop choice mechanism. The model predictability of the exact sequence of route transfers was about 60%. In this application, transit passengers were assumed to plan their transit trip based on their experience with the transportation network; with no prior (or perfect) knowledge of service performance.  相似文献   
825.
This paper examines the effect of passenger characteristics and terminal layout on airport retail revenue using an agent-based simulation approach. Simulation results show that passenger mix (that is, the mix of shopper types according to a typology of airport shoppers) has a profound effect on airport retail revenue; the larger the number of ‘shopping lovers’ there are among passengers, the higher the airport retail revenue. Results also reveal that group travel can lead to negative effects on retail in certain terminal layouts, and that the amount of free dwell time that a passenger has can affect spending due to less retail engagement. This paper shows a combined effect of passenger characteristics and terminal layout on airport retail revenue, and discusses the implications of these results for future airport terminal design that aims to maximise retail potential.  相似文献   
826.
吴迪 《上海汽车》2006,(7):25-28
文章结合物流在汽车行业竞争中的重要地位,对上海大众汽车有限公司(SVW)入场零部件物流外包战略的实施背景、运作情况进行论述。  相似文献   
827.
目的 观察羟乙基淀粉 (6 %贺斯 2 0 0 0 .5 ,HES)行急性超容性血液稀释 (AHHD)时血液动力学、血气及凝血功能的变化。方法 选择ASAⅠ -Ⅱ级在硬外复合浅全麻下行食道癌根治及全髋置换手术患者 5 0例 ,麻醉前 30~4 0min内输入HES(15mL·kg- 1 ) ,使血容量增加 2 0 %。当Hb低于 90 g·L- 1 时输入同型异体血。术中连续监测HR、BP、SpO2 ,于HD前 (H0 )、HD后 15min(H1 )、输入同型异体血前 (H2 )以及术毕 (H3)各时点抽取动、静脉血行血气分析、血常规及凝血功能检测。结果 HR、BP在整个手术过程中无明显变化 (P >0 .0 5 ) ;Hb、Hct在HD后各时点均降低 (P <0 .0 5或P <0 .0 1)。PT在HD后H1 、H2 ,FIB在H2 时均明显降低 (P <0 .0 5或P <0 .0 1)。结论 采用HES行AHHD对心、肺、肝、肾及凝血功能正常患者行血液保护是安全有效的 ,可避免异体血不必要的输入  相似文献   
828.
催化转化器非稳态温度场的数值模拟   总被引:1,自引:0,他引:1  
采用数值模拟的方法比较了催化转化器白载体和催化剂载体的非稳态温度场,并考察了载体壁厚对催化剂载体非稳态温度场的影响.结果表明,白载体与催化剂载体的升温特性不同;减小载体壁厚能够改善催化剂载体的非稳态升温特性.  相似文献   
829.
A routing algorithm called DNH for increasing efficiency of mobile ad hoe network is presented, which is based on a new cflteflon called TSS (Temporarily Steady State), combining with wireless transmission theory that makes networks topology correspondingly stabilization. Also the DNH algorithm has the characteristics of giving up queuing in a node, but selecting another idle node instead of the node for forwarding data packets if the node has a full throughput. Simulation evaluation shows that selecting another node is better than queuing in a full throughout node if some conditions are satisfied, especially during a sea battle, every warship in ad hoe network wants to contest time and increase propagation reliability. The DNH algorithm can help decrease routing time, and raise efficiency of marine ad hoe networks.  相似文献   
830.
二维水翼型空化流的数值计算(英文)   总被引:2,自引:0,他引:2  
In order to predict the effects of cavitation on a hydrofoil, the state equations of the cavitation model were combined with a linear viscous turbulent method for mixed fluids in the computational fluid dynamics (CFD) software FLUENT to simulate steady cavitating flow. At a fixed attack angle, pressure distributions and volume fractions of vapor at different cavitation numbers were simulated, and the results on foil sections agreed well with experimental data. In addition, at the various cavitation numbers, the vapor fractions at different attack angles were also predicted. The vapor region moved towards the front of the airfoil and the length of the cavity grew with increased attack angle. The results show that this method of applying FLUENT to simulate cavitation is reliable.  相似文献   
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