5000标箱以上的集装箱船将风云于2005年

当2002年集装箱航运市场与造船业处于低谷而可望有出头时 ,不少人 ,包括航运界要人呼吁不要订造大船 ,避免即将复苏的航运市场不久再陷入低谷。确实有些大公司想乘船价探底时赶快订造 ,但又不敢下手 ,担心背上了大包袱就摔不掉了。但若错过机会 ,摇钱树落入对手们手中又不甘心     

造船生产计划管理的信息化研究

“造船日程计划管理系统“是为实现“数字造船“研究开发的船舶制造生产计划管理的软件系统.该系统可协助生产部门安排各类计划,平衡生产负荷,跟踪生产进度,对不同生产管理方式和产品结构具有很强的适应能力,利于缩短船舶建造周期,提高生产管理效率.     

一种新的综合滤波在INS/GPS/CNS组合导航系统中的应用研究

针对INS／GPS／CNS组合导航系统的特点，采用了基于H。滤波的神经网络代替传统卡尔曼滤波器，利用INS／GPS、INS／CNS两个局部滤波器的输出值，通过联合滤波器进行线性最优估计，且进行了计算机仿真。仿真结果表明，该算法在满足系统精度和容错性要求的基础上，有效地改善了系统的自适应性、实时性、鲁棒性等性能，是组合导航系统理想的结构模型。     

舰船噪声特性数据库系统的设计和实现

描述了舰船噪声数据库系统的总体设计和详细设计，系统功能模块，还包括系统配置、开发平台、数据库管理系统等。     

Dynamics of inorganic nutrient species in the Bohai seawaters

Within the frame of a Sino-German Joint Research Program, two cruises of “R/V Dong Fang Hong 2” were carried out in September–October 1998 and April–May 1999, respectively, to understand the dynamics of nutrients in the Bohai. Nutrient species (NO₃⁻, NO₂⁻, NH₄⁺, PO₄³⁻ and SiO₃²⁻) are determined colorimetrically on board for five anchor and 30 grid stations. In situ incubation experiments are performed to determine planktonic nutrient uptake and benthic exchange flux. Nutrient concentrations display short-term variability and seasonal change in the Bohai, with higher levels in shallow coastal waters than in the Central Bohai. The influence of riverine discharge on nutrient levels can be seen from salinity isopleths, nutrient distribution and species ratios. Near-bottom (nb) waters have similar nutrient concentrations as to the surface waters in the Central Bohai, whereas stratification takes place in the Bohai Strait and North Yellow Sea. In situ incubation experiments provide evidence that the uptake ratio (i.e. N, P) by phytoplankton is proportional to the ratios among nutrient species in ambient waters. Based on the data of this study and previously publications, a preliminary estimate of nutrient budgets via riverine input and atmospheric deposition is established. The results indicate that atmospheric deposition gains importance over rivers in delivering nutrients into the Bohai and sustain the new production, following recent decrease in riverine inflow caused by drought periods in North China and damming practices. A historical review of nutrient data indicates that concentrations of nitrogen increase and phosphorus and silica decrease in the Central Bohai over last 40 years. This potentially has an important influence on the health of ecosystem in Bohai (e.g. food web and community structure), though further study is needed to examine the scenario in more detail.     

Stress intensity factor measurement of cracks using piezoelectric element

A stress intensity factor (SIF) measurement method for cracks using a piezoelectric element and an electrostatic voltmeter is presented. In this method, an isotropic piezoelectric element is first attached near the tip of the crack. Then surface electrodes are attached to three different positions on the piezoelectric element. The electric potentials of the surface electrodes, which are proportional to the sum of the stress ( _x + _y ) on the structural member, are measured by an electrostatic voltmeter during load cycling. The mode I and mode II SIFs of the crack are estimated using the relationship between the SIF and ( _x + _y ). The applicability of the proposed method is examined through experiments and numerical analysis.     

先张CRTSⅢ轨道板张拉技术研究

双向先张法CRTSⅢ型板是具有我国自主知识产权的高速铁路无砟轨道结构,是在总结了日本Ⅰ型板,德国Ⅱ型板,国产道岔板以及后张法Ⅲ型板的优点上开发出来的一种新的无砟轨道结构。通过优化轨道板中预应力体系,采用双向先张预应力结构,既提高了轨道板整体强度,又克服和改变了由于钢厂或PC钢棒生产中因材质缺陷及加工制造工艺瑕疵造成成品板的钢棒"延时断裂"的问题;通过在预应力钢筋端部设置锚固板,既减小预应力的建立起来的长度,又可长久保持预应力值不损失,提高轨道板耐久性;预应力钢筋定尺下料,专用张拉千斤顶单根初张拉,然后整体终张拉,整体同步放张。     

液压仰拱台车在铁路隧道施工中的应用分析

针对以往采用整体弧形模板存在安装困难、支模和拆卸时间较长,模板支架钢筋消耗量较大、施工投入成本较高、占用仰拱作业场地较大、使用过程中不够灵活、施工效率低等缺点,对整体弧形模板进行改进,增加挂模板桁架、丝杠、液压系统等部件,形成全自动液压收支模板,制作成液压仰拱台车,从而确保模板快速定位安装,保证仰拱浇筑质量,加快施工进度,提高经济效益。     

西安地铁土地储备问题探讨

为解决地铁建设所需资本金,弥补运营亏损,减轻地铁公司还本付息压力,各个城市都在积极探索建设资金的筹集方式。许多城市陆续成立地铁土地储备中心,通过对地铁沿线土地进行收储,获取土地出让收益,用于地铁建设。文章对几个主要城市的地铁土地储备模式进行了阐述,并对西安市地铁土地储备工作的现状和存在的问题进行了探讨,进而提出了完善西安地铁土地储备模式的意见建议。     

建好地铁,用好地铁,充分发挥北京地铁在城市客运交通中的骨干作用

文章根据统计资料数据,分析了北京市公共交通运输的发展,提出地铁应在城市交通中发挥骨干作用,并对建好地铁、用好地铁提出了建议.