同轴成像激光非接触测量传感器的研究

介绍一种新型激光非接触位置测量传感器和相应的硬、软件系统、该激光测头有效克服了同类非接触式测头性度差，存在阴影效应等缺点。采用的专用线阵ＣＣＤ数据采集电路和相应的处理方法，显著地提高激光测头的测量速度和精度。该激光测头在华中Ｉ型数控加工中心上成功地实现了未知曲面的数控自动测量。     

回转曲面测量技术

针对回转体曲面，提出了一种利用三坐标测量机和回转工件台，在工件连续转动过程中，让测头沿母线运动，在圆柱坐标系中进行测量的方法．该方法具有测头的运动简单、安全、可靠性高、效率高等优点．论述了其工作原理、圆柱坐标的提取以及一些关键技术，包括测头系统的作用半径标定、转台回转轴线位置确定、被测零件的自动定心技术等．研制了由三坐标测量机、回转工件台、测头回转体和非接触激光三角法测头组成的实验系统，对易碎石膏零件进行测量，精度可以达到0．02mm．     

三维曲面激光数字化采集系统的研究

综合运胜机械、电子、光学、计算机等多学科的理论和技术，研究并开哪出激光数字化采集系统，实现了数控仿形加工中的非接触测量。基于光学三角测量原理、ＣＣＤ光电转换技术及单片机原理开发设计出了非接触的激光数字化仪。     

一种共聚焦激光测头轴线位置标定方法研究

针对在非接触式坐标测量机上所用激光测头轴线位置需要标定这一工程需要,通过测量标准圆弧,提出了一种最小距离评价方法,该方法在评价函数取得极小值的时候可以有效标定激光测头轴线的初始参考零位。实验结果验证了该方法的有效性与可靠性。     

鞋楦三维面数控检测系统

鞋楦三维面检测系统是鞋楦ＣＡＤ／ＣＡＭ系统的一个必不可少的重要部分．本文介绍一种基于数控检测原理，利用触发式测头，具有自学习功能的智能鞋楦三维面检测系统．系统由测量台、单片机、微机及软件系统等构成．它能对新设计的鞋楦母样、或者大批生产的鞋楦进行自动、高效、精确的测量，是鞋楦ＣＡＤ／ＣＡＭ系统的一个理想的配套设备     

智能化激光扫描测径仪的研制

通过建立新的扫描测径原理数学模型和提出设置“标准棒”法测量原理提高了测量的精度和稳定性．研制的智能化激光扫描测径仪以ＭＣＳ－５１单片机为核心组成测量控制系统．该系统的硬件部分由８０３１单片机作为主机，软件编制采用相应的汇编语言，具有实时控制、实时输出功能．该仪器作为一种非接触测量仪器，可对生产线上高速运动，高温状态下的棒、线材直径进行动态在线检测．     

微型五坐标测量机激光测头安装误差的标定

针对非接触式五坐标测量机激光测头安装位置误差较大且不易调整的缺点,建立了该五坐标测量机激光测头安装误差的数学模型.选取激光测头的不同姿态,通过测量实物基准的空间位置,给出了误差模型待标定参数的无约束最优化目标函数的外点法惩罚函数.通过计算个体之间的欧氏距离,剔除掉那些相似的个体,从而有效地避免了遗传算法易早熟的问题,完成了对误差模型的求解.实验结果表明,所建立的激光测头安装误差模型不仅适用于扫描测头,而且对触发测头也同样适用,可把该机的空间测量精度从(11.82+L/1 000)μm提高到(1.96+L/1 000)μm.     

薄孔壁厚和小孔径测量系统

由于相邻孔壁厚度的测量根据进刀量进行计算时精度很低，故提出了一种应用电容传感器对2个微小孔间相邻孔壁进行精密测量的系统．基于非接触式电容测孔传感器，研究了测头的电场边缘效应影响及保护环的宽度选择，设计了电容瞄准测孔传感器的测头对相邻小孔中心定位，利用电容差动测厚传感器测量孔壁，系统由1个瞄准测孔传感器和2个差动测厚传感器及三通道测量电路组成，处理数据后直接显示孔径和孔间壁厚．系统属非接触测量，无需修正测头及工件变形误差，实验证明，测量精度为0．5μm，     

非接触光学测头在金属强反射表面测量中的应用

强反射表面的高精度金属件和光学件的表面轮廓测量，是形貌检测领域的一个难点．文中提出了一种用于逆向工程领域的自由曲面非接触测量系统，其由三坐标测量机和主动式双目视觉形貌测头组成．通过摄像机标定了视觉测头，利用光学偏振技术消除了金属表面强反射光对测量的干扰．对扫描路径进行了规划，并根据金属表面加工纹理方向，选择采样策略．通过对量块表面的测量，验证了使用非接触方法测量金属强反射表面的可行性．研制测头的精度达到了0．05mm．     

被测表面特征对激光测头特性的影响

提出了基于坐标测量机,激光三角法测头,测头回转体的自由曲面非接触扫描测量方法,其中激光测头的输出值受被测表面的粗糙度,曲率以及颜色等特征的影响,存在相应的误差,为了减少这些误差,对其影响规律进行了实验研究,结果表明,表明粗糙度值太低,测头不能完成测量,原因是表面存在较强的镜面反射光,曲率越大,测量误差越大,因为光斑区域内的表面平均高度变化加大,颜色越深,测量误差越大,因为漫反射光信号过弱所致。     

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.