地铁民用通信建设相关问题考虑

本文主要对地铁民用通信建设规划和实施时的一些关键问题作个简单分析，并就建设中遇到的实际问题作主要说明．     

基于三层结构B/S模式的港航管理信息系统

随着世界港口和航运业务的迅速发展和计算机网络应用领域的不断扩大,通过计算机网络对港航信息进行管理已经成为一种必然的趋势。港航业务涉及到的港口、船舶和航线等相关信息,具有涉及面广、内容复杂、更新速度快等特点,如何处理好这些信息,为港航业务的发展提供方便快捷的信息化服务,本文研究了应用Browser/Server模式建立港航管理信息系统的可行性,并提出了初步的操作方案。     

威大线客滚船电气设计特点

本文重点介绍了威大线客滚船在电气系统设计中的主要特点。     

滚装船跳板系统可靠性分析

根据滚装船的任务特点,对其跳板系统进行任务剖面、寿命剖面分析,按跳板系统功能的逻辑关系,构建可靠性分析模型.在进行完整的定性分析基础上,开展较为准确的定量计算,找出系统的薄弱环节,为提高跳板系统的安全可靠性提供依据.     

计算机辅助审计在社保基金中的应用

从各地社保普遍业务方面的共性出发,探讨建立统一的社保业务审计标准,运用计算机辅助手段,提高审计工作的准确性和效率。并通过审计实践,阐述了社保基金审计软件的技术实现。     

摆线齿轮加工节圆为任意值时滚刀齿形曲线的计算

本文以点齿代换法为媒介,从运动学和几何学出发,导出了摆线针轮减速器中摆线齿轮在任意加工节圆时,计算滚刀齿形曲线的通用方程式,此方法避免了现行啮合计算法中繁杂的微积分等数学运算,是一种较为简便的计算方法.     

大骨节病病因研究——病区天堂村饮水中有机物的测定(Ⅰ)

本研究应用XAD树脂富集,色谱/质谱联机分离鉴定的方法。对大骨节病病区(麟游县天堂村)三种饮水与对照(西安医科大学校园)深井水作了痕量有机化合物的测定分析。从天堂河水、深机井水、窑水与对照水样中分别检出了40种、31种、19种和10种有机化合物,且对每种检出物的结构式、分子量和峰面积均作了分析测定。其中芳核化合物分别为25种、19种、8种和4种。病区三种水样中均检出了烯类、烯酮类、酮类和萘类、苯并噻唑等稠环芳烃化合物;仅在河水和深井水样中检出了茚类化合物;在对照水样中未发现上述有机物。此结果未见文献报导。上述诸有机化合物可能是值得重视的可疑病因因素,但其真正的病因流行病学意义尚需进一步研究探讨。     

ABS/EDS液压装置轮缸增、减压特性测试

汽车防抱死制动系统(简称ABS)是提高和改善汽车制动性能的重要途径.因此,通过介绍ABS的作用、发展历程及远大前景,简单说明ABS/EDS组成及原理;同时通过试验测试ABS通道和EDS通道的特性,可为今后研制开发ABS/EDS以及TCS、ESP等液压装置奠定基础.     

Two- or three-layered box-models versus fine 3D models for coastal ecological modelling? A comparative study in the English Channel (Western Europe)

The general trend in ecosystem modelling is to improve the spatial resolution by shifting from rough box-models to fine 3D models. Despite the continuous speeding-up of computing, 3D models involving numerous state variables may remain intractable, especially for parameter calibration, when processes with long half-life periods (i.e, from years to decades) are introduced, such as the behaviour of organic matter in sediment and population dynamics of benthic species. In these cases, a first approach can be provided by fast-running box-models, if they take into account the most crucial hydrodynamic properties of the system. In a macrotidal shelf sea such as the English Channel, the long-term horizontal transport can be summarized by the tidal residual circulation, and the vertical stratification can be sketched by a two- or three-layered integral model.This paper compares the results obtained in the English Channel area by the same biogeochemical equations of pelagic primary production, coupled to 1) a two-layered box-model 2) a three-layered box-model (i.e., with an intermediate cline layer between surface and bottom ones) and 3) a fine-gridded 3D model. Comparison is focused firstly on thermal stratification and summer dinoflagellate blooms in the north-western Channel and secondly on the haline stratification and the sequence of blooms obtained in the eutrophicated Seine river plume. Comparison shows that box-models act as low-pass filters which reproduce correctly the weekly mean time-course, but greatly reduce the variance locally observed in a tide-oscillating plume region. As far as global characteristics are concerned, such as the annual primary production, or the percentage of variation in annual production after reducing the nutrient loadings, the box and 3D models gave very similar results. This conclusion reinforces the usefulness of using box-models as a first approach in long-term processes, for which a long transient phase is expected before reaching the annual periodic solution.     

基于GPRS的GPS/DR车辆组合导航的研究

分析用GPRS网络传输车辆定位信息及其他车辆信息的优点,论述GPS/DR组合导航的原理,描述车载移动终端硬件结构,并且给出一种实现方法。基于GPRS的GPS/DR组合导航将成为车辆导航的主流。