波纹管阻垢性能试验研究

对波纹管和光管的阻垢性能进行了对比试验研究。结果表明 ,波纹管比光管相结垢速度慢 ,相对稳定后传热系数大 ,证明波纹管内湍流程度较高 ,周期性的轴向流速脉动明显阻碍了积垢的形成。由于波纹管具有良好的强化传热性能和防阻垢等性能 ,能满足石油化工行业管壳式换热元器件应用的需要     

高温机械密封用焊接金属波纹管失弹特性分析

利用ANSYS软件对高温条件下机械密封焊接金属波纹管进行了失弹分析,分别考虑了轴向端面压力、组合力、温度以及力热总载荷对波纹管弹性性能的影响.分析结果表明,各类力载荷及热载荷分布对波纹管弹性性能均产生影响,不同作用载荷下得到的允许压缩位移值不同;压差等载荷引起的应力强度对波纹管的影响程度与压缩位移有关.在设计和使用过程中应综合评定各操作条件下的波纹管性能,为高温机械密封波纹管工程应用及结构优化设计提供参考.     

波纹管的发展与应用

回顾了波纹管的发展历史，评述了波纹管的静力和动力特性以及隔振降噪性能等方面的研究工作。对波纹管在工程设计和理论研究中的一些主要成果作了较详细的总结，指出了现存的主要问题，展望了未来的发展方向。     

波纹管内的流动与传热强化研究

通过数值模拟和实验验证考查了流体在波纹管内的流动与传热情况,研究了不同的流体雷诺数、波形及管径大小对波纹管强化传热性能的影响,探讨了其强化传热机理。研究发现,在湍流范围内,波纹管的强化传热倍数达到相同条件下直管的1.78~3.10倍,且最佳强化效果出现在Re=10000附近;文中拟合出的考虑波形影响的波纹管内传热准则方程,对波纹管的工程设计和应用具有一定的指导意义。     

波纹管式抛撒机构抛撒过程建模及仿真

建立了子母战斗部波纹管式抛撒机构抛撒过程的系统内弹道理论模型并进行了数值计算,分析了该机构的结构和工作原理。根据波纹管膨胀做功过程的特点建立了波纹管运动模型、容积及有效推力面积变化模型。编制程序并进行模拟计算,获得了抛撒过程的弹道性能曲线。仿真结果说明了模型的可行性。该文研究可为波纹管式抛撒机构的结构设计和优化以及装药结构的设计提供理论指导。     

膨胀波纹管焊缝缺陷的检测及影响评价分析

焊缝可靠的性能是膨胀波纹管技术成功应用的关键因素之一。针对膨胀波纹管焊缝检测方法和性能评价标准缺失的现状,引入了数字化X射线平板成像技术。结合图像处理软件实现了波纹管焊缝缺陷的检测,可准确检测出缺陷的类型、尺寸及所处的位置,检测精度可达到0.01 mm。分析了气孔型、未焊透型和裂纹型这三种缺陷分别在焊缝的凹区和肩区时,缺陷的轴向宽度、径向深度、环向长度等参数对膨胀性能的影响,给出了30 MPa膨胀压力下的临界失效尺寸。人为地在焊缝上制备了特定尺寸的缺陷,通过水力膨胀试验,验证了计算结果的可靠性。该研究成果为膨胀波纹管的焊缝质量提供了检测方法,为焊缝性能的评价提供了依据。     

波纹管壳式汽-水换热器的开发与设计

分析和研究了波纹管的传热性能 ,并对某地集中供热工程使用的波纹管壳式汽 -水换热器进行了选型和设计 ,为这种新型元件应用到换热领域提供了一定的理论和设计依据     

山区公路钢波纹管涵抗滑移设计研究

山区公路存在地形起伏较大、地质情况复杂、施工工期紧等问题,而钢波纹管涵因其结构性能的优越性,能良好地适用于山岭重丘区,但在设计时往往存在涵底纵坡较大的问题,本文从钢波纹管涵的受力分析入手,根据工程实例,提出了以防滑墩的形式解决问题的方法,为山区公路钢波纹管涵的推广应用提供了借鉴。     

正弦型波纹管强化传热机制的数值分析

基于Fluent软件建立了正弦型波纹管内流体的数值分析模型,研究了湍流状态下管内流体的流动与传热特性,分析了波纹管不同结构参数及流体进口速度对管内强化传热性能的影响规律。研究表明:当雷诺数Re相同时,正弦型波纹管内流体的平均努赛尔数Nu是其当量直径光管的1.65~2.67倍,且当Re约为28 000时,传热效果最佳;波高、波长对波纹管强化传热均有较大影响,在高雷诺数条件下,经过结构优化的波纹管能使回流区与主流区交界处形成不稳定的剪切层,此时传热效果达到最优。     

HDPE 双壁波纹管的性能与应用

高密度聚乙烯（HDPE）双壁波纹管是一种新型管材,具有优良的管道性能。通过在建设北路排水工程中的实践,表明HDPE双壁波纹管在城市市政建设中有着广阔的应用前景。     

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.