在线称重系统中嵌入式速度控制器的设计

介绍了一种在线称重系统中的嵌入式速度控制器,给出了控制器的硬件结构及主要部分的工作原理,并详细介绍了其软件设计思想。通过现场测试,该速度控制器反应灵敏,运行稳定。     

电梯应急平层功能开发

本文主要介绍了如何利用变频器的蓄电池功能设计开发电梯停电应急运行装置,并阐述了运行装置的原理和逻辑结构。     

300t大型造船门式起重机的设计

介绍我公司自行设计制造的 30 0t× 112m× 70m大型造船门式起重机的主要特点 ,材料选用、主结构形式、起升机构及大车运行机构的控制方式。概述了有限元法在 30 0t大型门式起重机结构计算中的应用。     

基于ISaGRAF的船舶空压机实时监控系统

空气压缩机作为气动控制系统的气源设备,其在运行过程中的稳定程度和可靠性直接影响到船舶的安全,因此必须对空压机的运行进行全面的监控。文章通过分析ISaGRAF控制软件的体系结构和运行机制,提出了船舶空压机实时监控系统的软PLC实现方法,介绍了该系统的结构、主要功能特点及软件设计等。     

船模试验数据分析与处理软件开发

本文从软件工程角度，介绍了船模试验数据分析与处理软件系统的特点、各个子系统主要功能、数据库结构、船模试验数据处理及实船性能预报软件，以及系统运行的硬件配置、微机系统的正确设置。     

FACTS在电力系统中的应用

柔性交流输电系统（FACTS）是近年来出现的一项新技术,本文对柔性交流输电技术的概念及发展现状进行了简要介绍,详细论述了 FACTS 中几种主要控制器的结构原理及应用。最后总结了 FACTS 控制器在电力系统潮流控制、系统振荡、稳定性运行中的重要作用以及FACTS的发展前景。     

大吨位船舶船尾升降平台控制系统设计

通过对国外进口设备及项目自身特性和组成的分析研究,结合模块化的设计思想,研制出大吨位船舶制造专用液压安装平台。通过力学计算及结构变形分析,为系统设计提供参考。同步控制策略保证系统运行稳定性。本文主要介绍了系统构成及控制策略实现。     

《港口工程总平面CAD》新版软件的开发研制

文章介绍《港口工程总平面ＣＡＤ》新版软件的功能，主要技术特点，系统总体结构，运行环境及技术路线。     

基于温度控制的油漆加工系统的应用研究

介绍了某油漆厂油漆加工过程计算机控制系统的组成、基本方案、控制软件的结构和主要功能模块设计,VC++6.0多线程技术在智能仪表通信中的解决方法以及温度控制仪表网络通讯的实施过程.实现了网络数据通讯、集散控制以及数据管理.应用表明,系统运行稳定可靠,提高了油漆加工技术的自动化及产品质量.     

液阻软起动的研究与应用

文章主要阐述了电动机的机械特性,电动机软起动的含义,用可编程序控制器控制电动机软起动的硬件结构和工作原理,介绍了电动机软起动的可编程序控制器的程序设计思想,程序调试,故障处理和主要保护功能.并且介绍了到用户现场调试和运行情况.     

High-resolution surveys of the biogeochemistry of the New England shelfbreak front during Summer, 2002

We present the observations from a pair of field experiments at the New England shelfbreak front in June and August of 2002, each consisting of 14 cross-frontal surveys using the Lamont Pumping SeaSoar. Measurements of the front's physical, chemical, and bio-optical characteristics were made at high spatial and temporal resolution. The front, based on water-column hydrographic distributions, was found within a few km of the 200 m isobath during both cruises. We present here composite sections, based on averages of individual sections shifted in space to a common frontal location, of the cross-frontal distributions of these properties as a measure of the mean state of the front in both June and August. The observations show the familiar temperature, salinity, and density distributions of the summertime front, dominated by surface thermal heating. Nutrient and bio-optical distributions show the combined effects of water-mass exchange and biological processes. T, S, silicate, and phosphate distributions are suggestive of cross-frontal exchange of slope- and shelf waters, although transport mechanisms and pathways are not apparent. These properties, along with nitrate and optical measures of the suspended particle distributions, show vertical displacements of isopleths as the front is approached: property contours slope upwards toward the front from the shoreward side, and downwards toward the front from the seaward side. Again, actual water-movement pathways are not constrained by these suggestive patterns. Bio-optical distributions show elevated indicators of photosynthetic efficiency both seaward and shoreward of the front, but the front itself is a minimum in biomass. Accumulation of photosynthetic biomass appears to be controlled primarily by nitrate scarcity in waters within and above the pycnocline. At the base of the pycnocline, light limitation appears to be the controlling factor, although the base of the euphotic zone is deeper than the biomass maxima and the base of the pycnocline. Mechanisms explaining this phenomenon are unclear, but tenuous evidence suggests low stratification at the depth of the 1% light level may not allow phytoplankton to optimize for the low-light, high-nutrient conditions at depth. Cross-frontal differences in nutrient and bio-optical parameters, particularly in August, suggest distinct phytoplankton assemblages, and the presence of calcite-forming or nitrogen fixing groups to the community structure, especially in very shallow waters across the front and in pycnocline waters seaward of the front.     

面向复杂装备AR辅助维修的混合跟踪技术研究

装备维修是生产制造、作业运转的基础,特别是在船舶、航空等领域。由于在维修过程中装备结构复杂、维修人员经验技术不足和缺少直观维修手段导致容易导致维修效率低下和操作出错。因此,通过研究基于增强现实的装备维修方案,直观交互地进行维修作业,能够有效地提升维修的质量和效率。由于装备体型较大,结构复杂,给跟踪定位带来了新的困难,针对实际的工程需求,创新性地将主流方法进行结合,提出了多Marker和ORB-SLAM混合跟踪的方法。通过二次调整多Marker定位结果的动态权值,提高局部定位维修的精度和可靠性。分析比较现有的特征点算法,选择ORB-SLAM作为方案,实现全局的定位和导航,对维修过程给以指导,并设计开发装备诱导维修系统,为大型复杂设备地维修提供了通用解决方案。     

多因素数学模型在温州瓯江口浅滩围涂工程研究中的应用

建立了波浪、潮流、盐度、悬沙、底床冲淤等多种因素数学模型,在模型验证的基础上,对瓯江口温州浅滩围涂工程海区的波浪场、潮流场、盐度场、悬沙场、底床冲淤场进行了数值模拟研究,对温州浅滩围涂工程对瓯江泄洪、瓯江南北口分流比、乐清湾养殖业、瓯江口港口航道及状元岙深水区、南口口外滩地的影响进行了分析论证。分析研究结果表明,温州浅滩围涂工程是可行的。     

澜沧江-湄公河航道哈乐滩碍航特性及整治措施

澜沧江-湄公河航道上哈乐滩具有弯、浅、险、窄、急等特点。根据现场调查资料,结合数学模型计算结果,分析了哈乐滩成滩原因及碍航特性。哈乐滩右岸楠罗河山洪冲出的石块及大卵石堆积在溪口形成冲洪积扇,近年来冲积扇发育,进一步侵占河床泄水断面,同时岸线凹凸不平,导致滩险上段水流弯曲,中段坡陡流急,船舶枯水上滩困难。针对哈乐滩滩险成因及碍航特点,提出炸礁和修筑整治建筑物结合的措施,解决滩险碍航问题。     

Matching biological traits to environmental conditions in marine benthic ecosystems

The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for example, reductions in permanent-burrow dwellers within one of the regions potentially compromising the ability of the assemblages to process and store chemicals and waste products. However, the connections between environmental conditions and trait composition are complex and incorporate many factors. Experimental investigations will be necessary to determine the extent and consequences of these important relationships.     

防波堤及护岸越浪研究综述

近年来防波堤越浪方面的相关研究,分别在越浪影响因素、越浪量计算公式推导论证、越浪数值模拟与越浪量标准4个方面进行归纳总结.已有成果表明:1)越浪影响因素的研究多是集中于常规因素,包括波高周期,堤顶高程,坡肩宽度,护面块体,而对水流、风速、波浪谱以及水的性质等其他因素研究相对较少;2)越浪量计算公式研究中主要集中在影响越...     

How much can public private partnership really do for urban transport in developing countries?

A few cities in some of the larger developing countries in Latin America and Asia have made increasing use of multi-year concessions or franchises, competitively awarded to private companies, for construction and operation of urban transport infrastructure and for provision of public transport services. In view of the strong prospective growth of developing-country cities with large transport needs, and the rise in the emerging economies of potential new sources of private capital, it is important to see how effective PPP has so far been in this area. The experience is analyzed principally by thorough comparative review of what has actually happened for some of the main users to date: Bogotá, Santiago, São Paulo, Seoul, and several cities in both China and India. Despite delays and mistakes that have been made in development of most of the projects, the overall results, already delivered and in prospect, are very positive and urban public transport is benefiting substantially, with significant side effects on poorer people's access to work and to services, air pollution levels and road accident rates. The widest and most important advantage of the PPP arrangements, as compared with more conventional short-term contracting, is found to be the innovations, technical and managerial, developed, and, in particular, the mutual capacity building of the countries' private and public sectors and their more effective interaction. The experience in the six countries covered suggests that other developing-country cities may be best assisted to develop sound urban transport PPPs more rapidly through provision of help on chosen items among 7 elements that have proved particularly crucial but sometimes weak in the projects reviewed: Civic consultation systems, Land-use/Transport strategic planning, Land/property market management, Monitoring systems, Progressive policies, Economic regulation, and Public institutional framework for PPPs.     

具备开通闸条件的通航节制闸建设方案

通航节制闸运行调度原则与常规的船闸工程和水闸工程明显不同,针对其口门宽度、门槛水深、闸门形式、平面布置等关键技术问题,船闸工程和水闸工程规范尚无具体的要求。以邓楼节制闸重建工程为例,对现有的节制闸运行调度原则进行调整以满足开通闸通航的要求,同时通过实施工程补偿措施以满足原节制闸防洪水倒漾、引水灌溉、保护水质的功能。通过理论计算和对比分析等方法得知建设2孔净宽23 m、门槛水深5. 5 m的通航节制闸能够满足船舶安全通航和航道通过能力的要求,并得出"升卧式平面闸门能够适应长期低水头运行、高通航保证率要求特点"的结论。其确定运行规则、建设规模、闸门形式、布置方案的方法对类似项目的建设及船闸标准规范的完善均有借鉴意义。