基于DASYLab的动态流量测试系统

针对液压系统流量的动态测量,结合现有实验设备和基于微机电系统(MEMS)的新型流量传感器,通过DASYLab虚拟仪器开发软件开发出相应的动态流量测试系统.实验证实,基于MEMS的新型流量传感器能够检测频率高于200 Hz的流量脉动,具有较好的频率响应特性.开发的动态流量测试系统能够很好地满足实验要求,为优化新型流量传感器的设计提供了理想平台.     

基于MEMS的智能集成汽车传感器的研究

随着汽车传感器的迅速发展和MEMS技术的深入研究,基于MEMS技术的汽车传感器具有广阔的应用前景.本文从传感器原理、MEMS技术理论与制造工艺、智能传感器理论与控制算法、软件与硬件实现、以及集成原理与工艺等几个方面,综合运用MEMS技术、人工智能、信息融合、半导体加工等先进技术,研究基于MEMS技术的智能集成汽车传感器问题.最后对MEMS汽车传感器今后的发展研究进行了探讨.     

简述一多流量传感的微型电子机械系统

微型电子机械系统(MEMS)是当代电子技术的又一重大突破,是近年来发展起来的一种新型多学科交叉的技术,其发展正受到社会的普遍关注.MEMS问世以来,已开发、研制了名种产品,其中尤以传感器类的产品为多.该技术将对未来人类生活产生革命性的影响这些产品已广泛应用于汽车工业、生物医学技术、仪器仪表制造业.本文将扼要介绍具有多种流量传感功能的MEMS.     

多惯性传感器的数据采集及其质量筛选研究

MEMS惯性传感器在商业上得到广泛应用,但由于MEMS工艺、检测电路等条件的限制,在精度和可靠性方面存在劣势,有些传感器误差较大或完全损坏。为此,设计了基于STM32的多惯性传感器数据采集系统,通过实验采集了大量的传感器数据,在惯性传感器的误差分析的基础上,提出了MEMS惯性传感器快速筛选方法,基于该方法对采购的批量MEMS惯性传感器进行了筛选,剔除了不可靠的传感器。结果表明,该系统稳定可靠、数据采集真实准确,快速筛选方法对MEMS惯性传感器的筛选十分有效,可用于工程实践中。     

福建省发展MEMS传感器的思考

MEMS传感器逐渐成为汽车电子的一个亮点。本文就MEMS技术与半导体技术之间的关系进行了探讨,列举MEMS传感器在汽车电子领域的应用,分析了福建省在发展MEMS传感器上面临的机遇与挑战。     

微机电系统压力传感器抗干扰系统设计

鉴于传统的硅基MEMS压阻式压力传感器普遍存在温度漂移和时间漂移误差,本文采用恒温控制和恒流源自校正方法针对上述问题设计和研究了一种MEMS压力传感器抗干扰系统。首先,简单介绍了传感器的各项参数和温漂、时漂原理。其次,设计并制作了传感器相关外部抗干扰电路。最后,对该系统进行实验测试。结果表明,抗干扰系统能减小传感器温漂和时漂误差,热零点漂移的绝对值由恒温前的0.0652%FS/℃降至恒温后的0.00788%FS/℃,热灵敏度漂移的绝对值由0.118%FS/℃降至0.0153%FS/℃,时漂补偿后预测误差由-3.436~0.875 kPa降低至-2.086~1.765 kPa。该设计对MEMS压力传感器温漂、时漂补偿等抗干扰方面的研究具有一定参考价值。     

一种新型的电子天平设计

本文设计了一种新型的电子天平,将杠杆式天平和电磁式天平进行结合,并采用了MEMS加速度传感器作为主要器件,通过力矩平衡原理来测量被测物的重量。基于MEMS加速度传感器的电子天平具有设计新颖、结构简单、体积小、精度适中的特点,对新型电子天平的设计做出了一定的探索和尝试。     

消费级MEMS惯性传感器的工程快速筛选方法

低成本MEMS惯性测量单元(IMU)在商业上得到广泛应用,但由于MEMS工艺、检测电路等条件的限制,MEMS惯性测量单元在精度和可靠性方面存在劣势,其中有一部分完全不能使用.针对这一问题,提出一种切实可行的MEMS惯性传感器的工程快速筛选方法,设计了24传感器的批量数据采集平台;根据Allan方差原理,对15枚MPU6050进行了原始数据曲线和Allan标准差的双对数曲线的计算和绘制.通过分析,剔除了其中的6枚不能够使用的器件,确定了9枚平均性能器件,剔除率达40%.避免了因劣质器件问题导致实验数据不可靠性以及影响用户的体验,大幅度节约MEMS惯性传感器的筛选时间,确保了后续系统集成的顺利进行.该方法也适用于高成本MEMS惯性传感器筛选出优质器件.     

基于 MEMS 辅助的单基线北斗融合测姿算法

载体的姿态信息是导航的重要参数,随着北斗卫星导航系统（Beidou navigation satellite system,BDS）和微机电系统（micro-electro-mechanical systems,MEMS）惯性传感器的发展与完善,高精度、低成本、自主化的融合测姿技术具有广阔的应用前景,因此,提出MEMS辅助单基线北斗融合测姿算法。根据MEMS惯性传感器解算出的姿态信息确定基线向量的搜索范围,从而辅助模糊度函数法（ambiguity function method,AFM）减小整周模糊度搜索空间,提高整周模糊度快速求解的成功率和计算效率。将BDS输出的姿态角信息作为观测信息,对MEMS陀螺仪解算出的姿态信息进行实时校正,实现BDS和MEMS传感器二者的数据融合算法。通过实测数据仿真验证,该算法能够解决信号失锁带来的整周模糊度求解困难的问题,并且测姿系统能在遮挡和动态等复杂环境下提供高质量姿态测量结果。     

煤层瓦斯含量拟合装备的设计

煤层瓦斯含量预测中需要对样煤的瓦斯含量进行测试分析。样煤瓦斯解吸速率随时间延长逐渐降低,所以需要采用一种极低压损的气体流量传感器进行测试。为适应这一需求,仪表设计采用了微机电系统(MEMS)流量传感器FS4001,通过混合信号处理器12位A/D转换实现气体流量采集,再根据样煤瓦斯解吸速率随时间变化的幂函数关系,自动拟合推导出自然状态下样煤解吸的瓦斯总量。该仪表实现了数据采集、多组存储、时间设定、解吸速率曲线显示、总量逻辑推导、损失量拟合等多项功能,在微气体测量领域有很好的应用前景。     

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.     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.