基于RecurDyn的带式输送机启动性能影响因素分析

带式输送机的启动性能会受输送距离、拉紧力和工作平面倾斜角度等因素的影响.为实现各影响因素的优化组合以提高启动性能,利用多体系统仿真优化软件RecurDyn建立了不同结构参数和拉紧力的带式输送机仿真模型.通过仿真分析得到了各个模型的启动时间和输送带所受拉伸力仿真结果,并同理论计算值进行对比.结果表明:适当改变结构参数和增大拉紧力能够提高带式输送机的启动性能.     

三维离散元法软件开发研究

提出由机械部件的CAD模型建立其三维离散元法分析模型,在此基础上实现CAD软件与自主研制的三维离散元法分析软件的集成,从而构建一种集设计和性能分析评价为一体的与散粒材料接触作用的机械部件的通用数字化设计方法和集成设计分析软件,为相关机械部件结构和尺寸参数的优化设计奠定了基础.介绍了自主研制的三维离散元法分析软件的结构、主要功能及关键技术的实现方法,包括提出的实边界和虚边界的概念等.     

集成化钢管成型机的设计

为设计一台高集成化的钢管成型机,用塑性有限元软件Dynaform对钢管在不同壁厚情况下的弯曲过程进行模拟,确定其结构参数对构件成型的影响,为构件、模具及机器设计提供依据.利用Creo软件进行模具建模,再通过Creo与CAD软件进行装配验证各设计尺寸的配合.在钢管成型机机械结构上设计了料斗、导料组件、工作台、机架、导流板,通过Creo与CAD软件设计零部件结构和装配结构,设计的液压传动系统,将自动上下料直至钢管成型等工序集成在一台机械上.经样机测试,该钢管成型机可以满足工作可靠、操作方便快捷、生产效率高的生产要求.     

尺寸公差标注的计算机辅助设计

本文介绍尺寸公差标注的CAD软件.该软件是对Auto CAD系统的二次开发.扩充了Auto CAD的性能.     

基于ANSYS的槽式太阳能桁架支撑结构数值分析

利用ANSYS有限元软件建立模型,根据桁架式聚光器的实际工况进行结构静力学仿真分析,并对该模型进行模态分析研究,得出影响聚光器结构和工作性能的共振频率值.同时应用ANSYS优化模块对桁架杆的尺寸进行优化,在满足设计要求的范围内,使桁架式支撑结构的重量达到最优值,既能实现产品正常性能,又能降低企业生产成本.     

带式输送机液压自动拉紧控制系统

介绍了大型带式输送机张力自动调节的必要性,阐述了带式输送机张力液压自动调节装置的调节原理,设计了一种新型的带式输送机张力的液压自动拉紧系统,分析了拉紧装置的特性并构造了拉紧系统的传递函数,在此基础上构建了使用这种控制系统的带式输送机的动力学模型和数学模型.并利用该模型分析了输送带张力自动控制过程,用实例分析了张力自动控制系统的性能,应用simlingk软件进行了系统仿真,结果证明这种液压自动拉紧系统具有较好的适应性和稳定性.     

基于PROE的箱型步进梁有限元分析

以金川阴极铜板自动包装生产线出料机步进梁为研究对象,首先利用大型三维软件PRO/E对步进梁进行三维CAD建模.然后通过有限元分析软件ANSYS对建立的模型进行网格划分.最后在四种不同工作状态下对步进梁结构力学性能进行分析,得到步进梁在工况二时出现最大变形与最大受力.将有限元仿真分析运用到工程技术领域,为解决同类问题提供了理论依据及参考.     

基于ANSYS的物料车车架的有限元静态分析

对物料车车架有限元模型进行静态强度分析.应用三维绘图软件Solid Edge建立车架结构的CAD模型,并通过工程分析软件ANSYS11.0进行网格划分和静态强度分析,获得物料车在不同工况下车架的变形量和载荷强度,校核该车架强度是否满足要求.     

带式输送机停机动态过程的计算机仿真

研究了带式输送机停机过程的动态设计,通过分析提出了输送机停机过程的力学模型为两种:第1模型与启动过程的力学模型相同,第2模型为具有固定端的振动模型·分析了制动力的传动机理;在综合各种停机方式的基础上给出了停机过程的分类,提出了控制速度停机、自由停机和制动停机的计算方式及其计算方法;开发了带式输送机动态分析软件BCD.20的停机计算部分;应用软件对停机过程进行仿真研究,对停机过程进行了分析;给出了停机过程的动态设计方法和拉紧装置行程的计算式;得出了不同的停机方式结束后输送带的张力分布是不同的结果·所提出的方法可用于大型带式输送机停机过程的合理设计,避免事故的发生     

加热炉钢结构中型钢标准件的生成方法

加热炉钢结构装配体在生成过程中需要大量重复使用型钢标准件,缩短标准件的生成时间成为设计者所关心的问题.针对型钢的结构特点,基于Solid Edge软件,将零件族设计思想应用于型钢标准件设计,使用参数信息表对型钢标准件进行整理和归类,在共享主体模型的基础上,通过特征组合和尺寸变化实现了指定规格型钢结构的快速生成.该方法同样适用于其他CAD平台标准件库的建立,可以缩短设计周期,大幅度提高设计效率.     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.