复合地层顶管机刀盘中心驱动液压系统的设计与分析

常规刀盘电机驱动顶管机在特定复合地层条件下经常出现超转矩、掘不动的情况。针对这种情况,设计采用刀盘中心驱动的变量泵-变量马达闭式液压系统。根据复合地层的要求,在理论计算的基础上,针对性地匹配变量泵-变量马达的运行参数,再利用AMESim软件对液压系统进行建模,对刀盘在低速、高速和脱困3种模式进行仿真分析。理论计算和仿真分析结果表明所采用的闭式液压系统能够较好地适应复合地层对掘进的要求。     

基于AIS数据的渔业船舶碰撞风险度评估模型

构建一种渔业船舶碰撞风险度评估模型,并对其求解方法和计算流程进行设计.将该模型应用到基于船舶自动识别系统(Automatic Identification System,AIS)数据的渔业船舶安全管理与评价系统开发中,在系统中进行AIS数据库重构和数据深度挖掘,引入模糊数学方法和层次分析法,实现对渔业船舶碰撞风险度的科学评估和预测.测试结果表明:构建的渔业船舶碰撞风险度评估模型和开发的渔业船舶安全管理与评价系统可靠,预测的结果可信,可为渔业船舶的安全管理和评价提供科学的方法.     

基于通勤模式的都市圈中心结构判别研究

面对日益严重的城市交通问题，城市管理者尝试从城市空间规划层面引导交通出行模式的转型，调节供需关系，缓解交通问题，而中心结构识别作为城市空间规划的重要步骤，在分析方法与数据应用等方面仍然受限。本文利用百度位置数据挖掘出的都市圈通勤数据，采用基于网格的DBSCAN(Density-Based Spatial Clustering of Applications with Noise)密度聚类算法，识别出我国35个主要都市圈的中心布局，并根据5种通勤模式的理论模型和相应的量化指标对都市圈中心结构进行判别，最后对主要中心结构下影响通勤效率的因素进行回归分析。研究发现，虽然不同都市圈的中心布局差异明显，但大部分都市圈表现为非均衡多中心结构。不同中心结构的 分布呈现出一定的地域特征，单中心结构都市圈主要位于中西部城市，而约束扩散结构和均衡多中心结构都市圈大多是由东部沿海开放城市发展形成。城市规模与通勤时耗的相关性最为显著，职住平衡度对通勤时耗也有较大影响。上述研究结果为针对性地制定不同都市圈的资源配 置策略和通勤效率优化策略提供了有效支撑，对都市圈空间规划和交通可持续发展具有一定的理论价值和现实指导意义。     

干湿循环作用下砂岩力学特性及能量损伤演化

内陆港口砂岩地基在水的循环作用下,岩石力学性能劣化,威胁港口地基的长期稳定性。为探究砂岩在干湿循环作用下的力学特性及能量损伤,开展不同干湿循环次数下的三轴压缩试验。结果表明:随着干湿循环作用的增强,砂岩力学性能指标逐渐衰减,当循环次数达到15次时,衰减幅度基本收敛;砂岩峰值强度、残余强度、弹性模量和变形模量的劣化度累积具有相似规律,干湿循环0~8次时累积速率较快,循环次数达到15次时累积速率放缓;在应力作用下,岩石吸收总能量随着应变增长而逐渐递增,耗散能累积主要集中在岩石破坏阶段。能量耗散导致损伤发展,损伤变量与耗散能走势较为一致。     

Green port project scheduling with comprehensive efficiency consideration

ABSTRACT

Ports are an important driving force for world economic growth, but they consume considerable energy. The marine sector has proposed the development of green ports to achieve low-carbon sustainable development. This paper presents a green project scheduling model of port construction to optimize comprehensive economic and environmental efficiency. Various realistic constraints are considered, including investment scale, energy savings, emissions reduction, and project priority. Comprehensive efficiency involves cost reduction, energy savings, emissions reduction, and other efficiency goals. The problem is formulated as an integer program and is solved using CPLEX in a general algebraic modeling system (GAMS). We use a representative port in China as a case port in solving its green project scheduling. The results show that the port can save 6,527 tons of standard coal, reduce 40,875 tons of CO₂, and save 49 million yuan per year in the five-year implementation period. The payback in investing in these green projects is less than six years. From an economic and environmental perspective, the comprehensive efficiency achieved is significant.     

Health externalities of ship air pollution at port – Piraeus port case study

This paper is employing the well-known methodology of impact pathway approach to assess the external costs in human health from ship air pollution at port areas. The passenger port of Piraeus, Greece is the scenery of the study. Piraeus port is in the vicinity of the greater Athens metropolitan area where almost half of the country’s population lives. Hence, this port is the central hub of the Greek coastal passenger ship system which connects the islands of the Aegean Sea with land and is characterized by heavy ship traffic. The case study presented in this paper assesses the annual external cost in human health from air emissions produced by all passenger ships and cruise ships calling the port of Piraeus. Health cost from ships at port has been estimated at both local (Athens metropolitan area) and regional level (entire territory of Greece). Results show that higher costs occur at the local level. The dominant pollutants creating this cost are particulate matter (PM_2.5, and PM₁₀). Overall, the results indicate that the health impact of Piraeus’s passenger port emissions is not negligible; however the cost of PM₁₀ is considerably lower than the corresponded cost deriving from the land based industries of the Athens regional area for which comparison has been available.     

PFI汽油机空燃比控制仿真及试验研究

基于发动机台架试验,建立并标定了进气道燃油喷射单缸汽油机一维仿真模型,探索了空燃比控制的新方法。依据经典控制理论,通过所建空燃比PID控制器与参数整定,实现了稳态空燃比控制。基于x-τ油膜模型,提出了其代数控制X-Y油膜方程,分析了进气道燃油传输过程对空燃比控制的影响;通过燃油阶跃扰动法,对X,Y参数进行识别,获得了X,Y参数MAP图,构建了离散化燃油动态补偿器,实现了空燃比在瞬态工况下的前馈控制。     

轮胎吊高架滑触线供电系统安全技术应用

实施"油改电"以后,轮胎吊高架滑触线供电系统在实际使用暴露了一些问题。为此,进行了改进。揭示了原供电系统的问题及原因。从5个方面采取了安全措施。有效提高了轮胎吊高架滑触线供电系统的安全性。     

120t双向两体客滚连接桥有限元分析及优化设计

为适应业务发展需要,烟台港设计了120t的客滚连接桥。介绍了利用Solid works、COSMOS works及ANSYS软件对120t连接桥相关部位进行分析和优化设计,保证了连接桥的质量。     

浅谈港口与班轮企业合营的意义及我国港航企业开拓国际市场现状

港口企业与班轮企业合营对提高双方及第三方竞争力都有很大的意义。介绍了我国港口与班轮企业合营的现状,分别阐述合营对港口方、对船公司及对第三方的意义。并分析了港口与班轮企业的海外业务。指出港口与航运企业合作是实现港口跨越式发展的较好方式。