基于非均匀有理B样条的轻量化船体曲面逼近

在数字化船舶设计过程中,基于插值截面线生成的船体曲面控制顶点数过多,不利于后续曲面的光顺和修改;基于非均匀有理B样条截面线生成的曲面,形状不可控.针对上述问题,提出了一种轻量化船体曲面逼近的设计方法.该方法通过对截面线进行2次逼近,生成船体曲面.在一次逼近中,应用等弦差法对截面线进行离散,得到曲线上的离散数据点;在二次逼近中,以截面线的节点矢量为设计变量,将最小化所有截面线在最小二乘意义上的逼近误差之和作为目标函数,构建截面线优化逼近模型.根据问题的性质,对自适应改变染色体长度的遗传算法进行改进,将该算法应用于模型求解.实船船体曲面逼近和设计算例表明,应用该方法对船体曲面进行逼近设计是可行的,并能满足工程设计要求,同时还可以减少船体曲面设计所需的数据量,为其他复杂曲面的轻量化设计提供参考.     

面向全生命周期管理的产品结构模型

针对产品全生命周期管理过程中信息不全面和不一致的问题,给出面向产品全生命周期管理的产品结构模型的概念和总体模型框架,分析产品全生命周期各阶段结构模型的建立原理和演化过程,结合物料表利用IDEF语言搭建产品结构子树模型之间的转换过程,从装配和零件的角度分析产品结构模型的建立方法,从而实现产品信息的全面性和一致性.研究结果表明,提出的产品结构模型可以和产品信息模型结构等结合,构成完整的全生命周期系统模型,实现产品的全生命周期设计和管理.     

基于云渲染的三维BIM模型可视化技术研究

利用BIM(Building Information Modeling)技术进行工程建设的精细化管理需要实现三维BIM模型的在线展示及交互操作.传统的三维图形可视化技术虽然能够实现模型展示,但存在模型文件格式兼容性差,对终端设备硬件要求高,缺少必要的交互功能等问题.针对这些问题进行系统分析,提出了一套基于云渲染技术的三维BIM模型可视化解决方案.其中包括源模型文件轻量化转换技术,基于HOOPS的图形引擎开发技术,以及基于云渲染的大体量模型浏览器展示和交互技术.通过系统研发实现了主流建模软件Revit、Catia、Microstation、Tekla模型源文件的轻量化转换,以及基于云渲染的图形引擎系统,并在北京至张家口铁路工程建设项目中进行了验证.     

建筑信息模型的建设项目管理

研究基于建筑信息模型的建设项目全生命周期管理,认为应用建筑信息模型可以解决建设项目全生命周期管理中对信息的需求,使信息的传递渠道、累积方式等多方面发生根本性的变化.构建相关的模型,对设计、施工和运营维护阶段应用建筑信息模型实现有效的管理进行分析.对在工程施工阶段应用建筑信息模型中的问题进行研究,并得出结论.     

变量化船舶型线表达与设计方法

基于变量化设计理论,提出船体型线的变量化设计模型,用于船舶型线的表达与设计.描述了使用该模型进行船体型线设计的计算机辅助设计(CAD)方法,其主要包括船体型线数据的管理、数学模型的定义,以及三维空间模型的建立和修改.用数学模型定义了型线设计各元素的位置信息和元素之间的拓扑关系,按照数学模型构建和修改三维空间模型,完成船体型线的设计.在船体型线的设计过程中,基于变量化设计模型对设计进行修改,能够实现型线设计方案的快速重构,避免重复设计,有效地提高了型线设计的质量和效率.通过使用船舶型线的变量化设计方法进行型线设计的实例,证明了该方法的实用性和先进性.     

基于WebVR的井冈山虚拟旅游系统架构设计

针对当前主流的 VR 虚拟旅游系统因虚拟场景重型及网络带宽有限等因素而存在不能使游客直接浏览WEB 页面,需下载插件或客户端系统才能浏览的问题,对虚拟旅游实景漫游系统的轻量化架构进行研究.研究3D场景轻量化建模、3D引擎调用和轻量化脚本设计等技术,搭建云存储传输平台,集成导游人等关键技术,架构“网上井冈山”WebVR系统.架构的系统将使游客直接实时在线快速浏览Web页面,提高系统交互感、沉浸感.     

船体主要结构三维实体模型快速建模方法研究

目前，三维建模方法在众多设计领域中被广泛应用。这里就三维实体建模在船体主要结构建模上的应用进行了研究，介绍了船体结构建模中的数学模型、零件标准库、几何算法等关键技术，并结合甲板结构建模设计实例提出了快速建模方法。     

基于GIS的公路辅助设计及信息管理综合系统开发

从系统的需求分析、数据组织与存储、结构体系、功能模块以及关键技术5个方面,介绍了公路辅助设计及信息管理综合系统的设计思路与实现方法.该系统整合了GIS与数据库、CAD等多方面计算机主流技术,实现了电子地图的浏览和空间检索,属性信息和地理信息的一体化管理,以及桥梁、道路信息的管理和报表制作、公路动态仿真、部分图形绘制的自动化、项目及相关设计文件的管理,提高了公路设计与规划的效率、质量与科学性.     

轻量化桥式起重机小车动力学分析

由于轻量化桥式起重机起升机构与传统布置形式不同,因此其零部件受力状态、设计要求也与传统计算方法不同.本文构建了小车刚柔耦合动力学仿真模型,研究了吊重起升过程中系统的动力学特性,分析了机构的受力状况,提出了轻量化起升机构设计的重要环节及薄弱点.基于轻量化桥式起重机小车试验平台,根据小车结构特点,对小车部分零部件进行动态试验研究,分析在典型工况下动力学特性,通过与仿真模型进行对比,验证了仿真模型合理性.本文对轻量化小车的设计进行了动力学研究,对掌握轻量化桥式起重机小车设计方法具有重要意义.     

基于产品生命周期的成本结构优化模型

提出了3种企业管理观及相应的成本管理观,并对其概念和内容进行了讨论.在此基础上建立了基于产品生命周期的成本结构优化模型.该模型由下列两部分组成:一是面向企业内部资源的成本结构优化模型;二是面向产品生命周期过程的成本结构优化模型.在后一模型中重点分析了供应商与核心企业的成本结构优化方法,并给出了评价的数学表达式.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.