GPS RTK与数字测深仪联合技术在水下地形测量中的应用

详细介绍了利用GPS RTK技术与数字测深仪联合进行水下地形测量的工作原理,巢湖航道水下地形测量,讨论了测量设备的选择、仪器参数设置、数据检验和测量过程中应注意的事项。     

利用长江口航道疏浚土进行横沙成陆 实施方案研究

根据长江口航道建设现状以及未来规划目标,结合横沙新港区的规划构想,提出利用长江口北槽深水航道、北港航道、南槽航道疏浚土,进行横沙新港吹填成陆实施方案有关吹泥上滩工艺、疏浚船机等方面的设想,初步分析实施方案的技术可行性和经济合理性,并提出利用航道疏浚土成陆的有益建议。该实施方案研究可为横沙新港成陆或长江口区域类似工程的设计施工提供技术参考。     

基于VRML的航道虚拟场景应用研究

虚拟现实技术在诸多领域中展示了强大的功能,近年来随着水利工程的发展,该技术更多的应用于水工设计中。航道工程设计整治中的地形实景再现有助于更直观地进行航道线的确定和相关设施的布局,用 ArcInfo 实现地形面的三维建模,得到虚拟场景的对象。并用 VRML 及脚本创建虚拟的场景,可以较快地实现从离散地形数据到虚拟航道场景的浏览。     

长江口横沙深水港选址及可维护性探讨

横沙东滩位于长江口拦门沙区域,该区域建设大型挖入式深水港的关键问题之一是港池及进港航道的可维护性。本文从自然水沙特性出发,对港池及其口门选址、港池及进港航道的可维护性等问题作探讨分析。分析结果认为:港池口门位置宜设置在横沙东滩东侧鸡骨礁及以南区域,开口方向宜偏SE向,口门及进港航道均需设置在10 m以深水域,由此港池及进港航道回淤量较小,港池进潮量较大,具有较好的可维护性。     

QPY-I型浅地层剖面仪

最近研制成功的 QPY-I型浅地层剖面仪,是一种根据回声测深原理,测绘水底地层分层结构的仪器。它与国内外同类型仪器相比,在声基阵及发射、接收系统的设计上有若干特点,从而有效地提高了它的探测性能,并且结构轻巧,操作方便,特别适合于港工建设、航道整治及近海和江湖区的浅层沉积物调查等多方面使用。 QPY-I型浅地层剖面仪在1981年3月由国家建委、中国科学院和交通部联合召开的鉴定会上获得通过,受到国内各方面专家的好评,并深受使用单位的欢迎。 本文将简要地介绍QPY-I型仪器的性能指标、仪器组成、设计特点及海上试用情况。 一、性能…     

杭州湾南航道独塔斜拉桥抗风性能试验研究

杭州湾大桥为目前世界最长的跨海公路大桥,主桥包括南航道和北航道两座大跨度桥梁,抗风稳定性是控制主桥设计和施工的主要因素。采用单梁法力学计算模型对杭州湾南航道独塔斜拉桥成桥状态及施工状态进行动力特性分析,并通过节段模型风洞试验方法进行了测振试验和静三分力试验,即可测定颤振临界风速、气动导数、涡激振动响应、抖振响应和静力三分力系数,据此分析评估该桥的抗风性能。风洞试验结果表明:该桥具有较好的抗风稳定性。     

基于AIS数据的航运物流港口调度优化研究

目的 针对宁波舟山港区的复杂航道水域与密集物流交通流,研究更加有效的调度方案,达成调度时间和等待时间最小化,即效率最大化。方法 分析宁波舟山港区航道的航行情况,提出交会处复杂航道水域存在的问题,以调度时间和等待时间最小为目标的多目标函数,建立复杂航道水域船舶调度模型。针对大量的船舶AIS数据,构建基于神经网络的航道水域调度模型,对不同类型、不同大小的船舶建立速度变化和船舶预测模型,实现对船舶调度状态的预测。设计以传统粒子群算法为基础的改良版船舶调度算法。结果 算法对模型求解表明,根据不同船长与间距可判别交通流拥挤程度进而对船舶进行调度。通过模型预测到可能产生拥挤,则应当选择小型船只走条帚门航道,大型船只走虾峙门航道,并且尽量避免产生拥堵。结论 使用该模型与算法可以有效地提升船舶调度效率,为复杂航运物流港口调度优化研究提供了一定理论基础。     

内河航道整治工程施工标准技术

随着我国经济的快速发展,水上航运事业呈现出一片繁荣景象。国家对航运事业大力推进,要求航道拥有足够的航运能力,各大航道的通航条件因此得到了大幅提高。提升航道的航行等级改善航行能力,需要先进的航道整治技术。近年来,我国对内河航道工程的投入不断加大,对航道通行水准的要求越来越严格。本文结合内河航道整治工程的概况,对航道整治的施工技术进行了探讨,为改善通航能力提供了技术参考。     

浅谈AIS船舶助航系统在长江引航中的应用

AIS整合了卫星定位,罗经、计程仪等,通过VHF无线电数据通信,在雷达和电子海图上显示等技术的航海、导航、信息通信的新型航行设备和系统。目前长江下游的电子航道图已设计完成,基于长江电子航道图,开发引航员助航系统,利用船载AIS设备,实现电子航道图显示与控制、船舶动态显示、碰撞及超速预警、船岸通信等助航功能。该系统的实现将有助于提升长江引航服务能力,减少引航事故的发生。     

关于航道服务品牌建设若干问题的探究

航道服务品牌建设对于我国航道事业发展具有重要意义。然而，在当前航道服务建设中存在一些问题。通过详细分析航道服务品牌建设的关键点，结合工作的实践活动，提出了加强航道服务品牌建设的几点建议。     

提高岩石膨化硝铵炸药的堆积密度研究

文章通过对影响膨化硝铵炸药产品性能的配方、膨化硝酸铵密度等因素的研究,分析了影响膨化硝酸铵密度和颗粒尺寸分布的真空度、膨化剂、硝铵浓度、溶液温度、设备等关键因素,结合连续化工艺设备特点,提出了一些提高膨化硝铵炸药堆积密度的方法,以达到改善炸药体积威力的目标。     

A new method for measuring fluid densities using the Taylor dispersion experiment

The density of a pure fluid or a fluid mixture is of fundamental importance in the design of equipment for fluid processing and in the development of theory describing thermodynamic and transport properties of the liquid state. A new experimental technique for measuring fluid densities is presented, which is based on the well-known Taylor dispersion experiment for measuring mutual diffusion coefficients. The equipment and working equation are both simple, yet experimental results show that the method is accurate to at least 0.1%. An analysis of errors indicates that the accuracy could be improved to 0.01%. This new technique is of particular virtue since it can be used to obtain simultaneous measurements of the fluid density and diffusion coefficient of a solute in the fluid, using data from a single experiment.     

硅铝调整剂对赤泥制备陶粒的影响

为经济有效地利用我国排放量巨大的赤泥,消除其对环境的污染,在对赤泥进行化学组成、矿物组成和热稳定性分析基础上,提出以赤泥本身方解石为发泡剂,外加废玻璃、膨润土为硅铝调整剂制备赤泥陶粒的研究,并利用XRD和SEM方法对所得陶粒的组成和内部结构进行了分析.结果表明:废玻璃、膨润土单独调整或联合调整均可优化赤泥陶粒的性能,但...     

Multi-functional honeycomb ceramic materials produced from bauxite residues

Red mud is a hazardous waste produced by the Bayer process during commercial production of alumina. In this study, red mud is recycled to produce industrial honeycomb ceramic materials. The materials and processing parameters including the type and size the pore-forming agent, sintering temperature, and stripping methodology are studied. The optimal sintering temperature is determined to be 1075 °C. The bending strength, porosity, water absorption capacity, and bulk density are investigated by X-ray diffraction and scanning electron microscopy. The bending strength exceeds 32.66 MPa after addition of calcium carbonate but the porosity and water absorption capacity diminish to 28.6% and 12.6%, respectively. Incorporation of coal powders increases the porosity and water absorption capability to 36.0%, 20.24%, respectively, but the bending strength drops to 21.69 MPa.     

基于体积扫描容重法的社区垃圾分类系统研究

目的 响应国家垃圾分类政策，通过设计社区生活垃圾分类设备检测系统，提高分类正确率，改善“混投乱投”的现状，从源头提高城市垃圾分类投递的准确性。方法 结合现有针对垃圾容重区间划分方法和多种评价标准，总结归纳各类垃圾的容重阈值划分区间，并将其作为垃圾分类的判断方法。设计体积检测模块，利用激光测距传感器点阵获得待测物切片遮挡图和截面积，并计算待测物体积，结合称重传感器计算待测物容重，并依据容重区间对待测物进行分类判断。结果 根据容重阈值分类标准，对多种随机样本进行检测。绝大多数可回收物和厨余垃圾的容重检测值在各分类的容重阈值内，可以被正确分类；其余样本在混合垃圾容重阈值内，符合边界条件设定和模糊垃圾的样本按其他垃圾标准处理的分选原则，检测结果符合分类要求。结论 基于体积扫描检测容重的社区生活垃圾分类系统可以满足居民前端投递环节中对生活垃圾分类检测的需求，有助于提高源头分类的准确性，能有效推进我国垃圾分类和再生资源利用工作的发展。     

Simplified Gradient Theory Modeling of the Surface Tension for Binary Mixtures

In this work, the gradient theory was combined with the volume translation Peng-Robinson and Soave Redlich-Kwong equations of state (VTPR and VTSRK EOSs) and the influence parameter correlation to predict the surface tension of binary mixtures. The density profiles of mixtures across the interface were assumed to be linearly distributed to simplify the gradient theory model. The only two inputs of the theory are the Helmholtz free-energy density of the homogeneous fluid and the influence parameter of the inhomogeneous fluid. The VTPR and VTSRK equations of state were applied to determine the Helmholtz free-energy density and the bulk properties. The influence parameter of the inhomogeneous fluid was calculated from a correlation published previously (Lin et al. Fluid Phase Equilib 254:75, 2007). The only adjustable coefficient of the simplified gradient theory was set equal to zero, which made the theory predictive. The surface tension predicted by this model shows good agreement with experimental data for binary non-polar and polar mixtures.     

位于弹性半空间上的理想流体层动力反应--平面SV波入射

根据弹性固体与理想流体动力学方程,导出了固-液介质交界面上波的透射与反射系数的理论公式,分析了平面SV波从弹性半空间入射到与理想流体层的交界面时,弹性半空间的弹性模量和密度,平面SV波的入射角和频率,以及流体的体积模量和密度对理想流体层动压力的影响。     

The influence of a layer of mud on the train of waves generated by a moving pressure distribution

Two-dimensional free surface flows generated by a moving distribution of pressure are considered. The bottom is assumed to be covered by a thin layer of mud. The mud is modelled as a viscous fluid. The problem is solved numerically by a boundary integral equation method. It is shown that the layer of mud produces a damping of the waves in the far field. Profiles of the free surface and of the surface of the mud are presented.     

Extension of the Neoclassical Theory of Capillarity to Advanced Cubic Equations of State

The neoclassical Redlich–Kwong (RK) theory of capillarity is extended to the Soave–Redlich–Kwong (SRK) and Peng–Robinson (PR) equations of state. Use of the SRK and PR fluid models results in poorer predictions of interfacial tension compared to the RK model because the RK overpredicts vapor densities to a greater extent than SRK or PR, reducing the corresponding RK interfacial tension predictions to be in better agreement with accepted values. The limits of the theory applied to cubic equations are reached by proposing modified SRK and PR fluid models based on a known interfacial tension datum and knowledge of the fluid molecular structure. These modified fluid models provide improved accuracy in interfacial tension predictions of 6% (SRK) and 10% (PR) for the fluid set in this study when compared to applying the RK model (17%). These modified fluid models also provide improved predictions of bulk liquid density, but sacrifice accuracy in pressure and vapor density predictions.     

Modeling Relaxation Processes for Fluids in Porous Materials Using Dynamic Mean Field Theory: An Application to Partial Wetting

We review a recently developed dynamic mean field theory for fluids confined in porous materials and apply it to a case where the solid-fluid interactions lead to partial wetting on a planar surface. The theory describes the evolution of the density distribution for a fluid in a pore that has contact with the bulk during a quench in the bulk chemical potential. In this way the dynamics of adsorption and desorption can be studied. By focusing on partial wetting situation we can investigate influence of a weaker surface field on the mechanisms of capillary condensation and desorption. We have studied the dynamics of pore filling in a quench of the chemical potential between two states either side of the pore filling step, tracking the density distributions during the process. The pore filling process features an asymmetric density distribution where a liquid droplet appears on one of the walls. The droplet spreads and grows in size and this is followed by the appearance of a liquid bridge between the pore walls (for longer pores two liquid bridges are seen). The density distributions obtained in the dynamics resemble those obtained from static mean field theory in the canonical ensemble for an infinite pore without contact with the bulk.