基于CPLD与单片机的控制系统设计

结合CPLD与单片机设计了一种数据采集控制系统。A／D转换采用ADC0808芯片,转换精度为8位;方位采集通道为水平方向和俯仰方向,具有错误报警、焦距调节等功能,数据采集具备良好的实时性。该系统实现简单,可靠性好,具有很强的可移植性,可广泛用于全方位、高精度数据采集系统的实现。     

多通道高速数据采集电路设计

在高速数据采集系统中 ,多通道高速数据采集电路设计是一个难点。本文以一种典型的多通道高速数据采集电路设计为例 ,详细说明多通道高速数据采集、转换、存储技术及具体实现方式     

多通道高速数据采集电路设计

在高速数据采集系统中,多通道高速数据采集电路设计是一个难点。本文以一种典型的多通道高速数据采集电路设计为例,详细说明多通道高速数据采集、转换、存储技术及具体实现方式。     

汽轮机无线热力特性测试系统设计

以汽轮机热力特性数据的无线采集为设计方向,设计并实现了一种基于无线射频单片机nRF9E5的新型无线数据采集系统,该系统具有低功耗和抗干扰性能,能够满足火电厂数据采集的要求。     

基于FPGA的高速数据采集器

介绍了一种基于FPGA的高速数据采集器,给出了系统方案设计,并对系统各部分电路设计进行了详细介绍。对高速数据采集系统中串并转换功能的实现方法进行了详细阐述。该高速数据采集器由于采用了FPGA+DSP平台设计,使得该系统具有较强的通用性和应用价值。     

基于LabVIEW的多通道振动测试与分析系统

为利用计算机系统迅速高效地实现测试与分析功能,研究了一种基于虚拟仪器软件LabVIEW的多通道振动测试与分析系统。该系统中,专门设计的外置式数据采集箱具有多通道输入信号调理,内、外触发采样控制,A/D转换和先入先出(FIFO)缓存等功能;采用增强型并口(EPP)实现计算机与外置数据采集模块的高速数据传输。结果表明,该系统具有较高精度,并能实现振动信号的采样、存盘、分析和回放功能。     

带浮点放大器的CPLD数据采集系统设计

采用浮点放大器和CPLD设计了多通道数据采集系统.其浮点放大器根据输入信号范围,放大适当的倍数,保证了数据采集系统的动态测量范围;CPLD具有丰富的内部资源和大量I/O管脚,处理速度快,可实现灵活多变的控制流程;双端口RAM作为A/D转换与CPU之间的桥梁,为高速数据吞吐提供了有力的硬件支持;结合以上几方面的优势,系统总体上实现了高速、高精度数据采集.     

基于USB接口的数据采集系统设计

ARM2378为数据采集系统的控制核心,系统中还包括信号数据采集电路、电源电路和报警电路等。设备与PC主机能够实现USB接口通讯,并能够进行数据的采集、转换、存储、异常报警等。便于系统的维护与升级,提高了开发效率,开发周期也被大大缩短。     

全频段多系统全球导航卫星系统数据采集系统的设计与实现

基于FPGA设计实现了一种全频段多系统全球导航卫星系统(global navigation sattellite system,GNSS)数据采集系统。该系统由宽带天线、宽带射频前端、A/D转换模块、下变频模块、滤波器模块、数据存储模块等构成,可以实现四大导航系统的全频段覆盖,具有并行数据采集通道多、采样速率高、可灵活配置等特点,能够满足全频段多系统软件接收机的各种处理需求。对GALILEO在轨卫星实际数据的测试结果验证了数据采集系统的正确性。该数据采集系统可用于GNSS全频模拟信号源的验证以及在轨导航卫星信号的质量监测。     

基于C8051F020的心电测量系统设计

为研制一种能够在临床上使用的心电测量系统,以C8051F020单片机为采集控制中心,运用模拟信号采集和数字信号处理技术,实现心电信号的采集。完成了心电测量系统的设计,该系统具有实现各种控制、数据采集和A/D转换等功能。实验结果本系统运行稳定可靠,满足了临床准确采集心电信号的需要。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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