极性相关与LMS算法的流速测量系统研究

为了解决恶劣环境中噪声等因素对流速测量系统的影响,提出了两种抗噪算法。首先概述了流体流速测量的基本原理,分析了极性相关算法的结构、电路实现、以及峰点位置确定,然后介绍了最小均方算法(LMS)在流速测量中的应用,并对两种算法进行了实验仿真。根据两者的蒙特卡洛法仿真实验可以看出,在无噪及-20d BW噪声条件下,两种算法皆可进行精确的流速测量,且峰点位置清晰。但在噪声功率增强达到-15d BW时,两者的实验仿真出现较大偏差。基于LMS算法仿真得出的测量速度依旧能良好的反应蒙特卡洛法设定速度,但是基于极性算法仿真得出的测量速度已经不能良好的反应蒙特卡洛法设定速度。在噪声功率达到-10d BW时,基于LMS算法仿真得出的数据依旧良好,此时基于极性算法仿真得出的数据已经完全失真。实验结果表明,在有噪环境中时,极性相关算法的测量精确度降低,而LMS算法因为能根据外界因素自动调节自身参数,仍然可以进行精确的流速测量。     

基于极性相关算法的流速测量系统研究

流速测量作为水灾预警的重要组成部分意义重大,但是常规测速仪器精度较差,因此提出了一种极性相关算法进行流速测量。本文概述了相关法在流体流速测量中的基本原理,进行了相关法的算法介绍,在此基础上提出了改进型算法——极性相关算法。此后进行了极性相关法的算法分析,电路实现。根据蒙特卡洛(Monte Carlo)法进行的仿真实验表明,极性相关算法在峰点位置确定上可以代替普通相关算法,而且由于其算法的特殊性,因而具有较好的抗干扰作用。在实验测量速度与蒙特卡洛法设定速度的比较中可以发现,在两采样传感器间距符合一定条件的情况下,测量速度与其相应的拟合曲线拟合度较好,测量速度能精确的反应相应的蒙特卡洛法设定速度,这也从实验上验证了此算法的可行性,可以进行精确的流速测量。     

基于DSP时钟抖动测量系统的研究与实现

介绍了一种基于DSP技术高精度抖动测量系统的实现方法,以DSP系统作为抖动测量系统的信号处理和控制的核心,该系统利用多相位数据转换跟踪环的方法可以对抖动进行高精度测量。系统设计方法是基于一种系统级电路,通过DSP算法模型和抖动误差的推导完成对系统的定制。利用Matlab可以进行仿真和验证。在采样周期相同的情况下,此种方法的测试精度相对于传统的模拟测量方法和单相位测量方法的测试精度提高很多(均方根误差最大时,只是传统方法的方根误差的1/6)。而且测量精度非常稳定,操作也很简单。     

多功能电参量测量仪的系统设计

介绍了谐波功率测量的数字信号处理算法以及一种基于DSP技术的多功能电参量测量仪的系统设计。采用DSP和FPGA及A/D等集成电路构成系统实现了电流和电压的平均值、有功功率及功率因数等电力参数的测量及波形显示。本系统还可以通过通信模块进行远程测量和数据传输。     

基于DSP的数据采集与处理系统的设计

构建了一种基于DSP的数据采集和处理系统,介绍了系统硬件和软件设计方案,着重讲述了TMS320F2812型DSP在数据处理中的作用,设计实现了FIR滤波器和FFT算法。该系统通用性好,可靠性高,实时性强,可以实现快速的测量和传输。     

互相关技术在海底沉积物电阻率测量中的应用

海底沉积物的电阻率测量技术广泛应用于海洋地质调查、海洋环境研究等领域,基于海底钻机的原位探测仪为平台,开发了一套电阻率测试系统,为精确处理电阻率探头输出的微弱电压信号,对互相关算法进行了理论推导和MATLAB仿真,并在实际电路中以互相关算法在DSP(TMS320F28069)的移植为核心设计了相关软硬件,大量的对比试验表明,互相关技术是一种有效的微弱信号处理方法,可提高海底沉积物电阻率测量的精度和抗干扰能力.     

基于DSP的电网监控系统

提出了一种基于DSP芯片TMS320F240的新型电网监控系统,该系统能同时完成对三相电压和三相电流的检测,消除了电压和电流相位差的测量误差;给出了相关监控的基本原理和设计思路,并对该系统的硬件结构和软件设计中的关键部分进行了讨论.插值FFT算法的引入使该系统的测量精度进一步提高.实际应用表明,该系统能较好地完成对电网的监控.     

DSP6416在数字图像处理中的应用

阐述了高速图像目标测量系统的DSP实现，运用高性能DSP（TMS320C6416）完成实时图像处理，研究了一种快速图像预处理和模式识别的相关算法，并给出系统的程序开发流程，包括DSP端和主机端两个部分。实验证明该系统性能可靠，识别效果较好，有较高的实时性。     

基于多DSP的自适应数字多波束形成的并行算法及其实现

在深入研究自适应DBF（数字波束形成）算法的基础上,针对由TigerSHARC201处理器构成的多DSP并行处理系统,提出了一种基于自适应数字多波束形成的并行处理算法。笔者给出了该算法在多DSP并行处理系统上的算法映射,基于此映射方案,比较了SMI、HTP和MTP三种典型DBF算法,并对MTP算法进行了改进。系统试验证明了该并行处理算法具有很好的并行性及实时性,且改进的MTP算法的性能较传统MTP算法有显著提高。     

脉冲超声互相关测量系统在两相流体流速测量中的应用(英文)

相关流速测量技术正在迅速地发展,它为两相或多相流体流动的测量提供了一种有力的工具。应用超声传感器的相关测量系统有许多显著优点。因而特别适用于工业应用。它没有可动部件,对流动无接触,可在原有工艺管道上安装“夹钳”式传感器。本文作者提出了一种简单的脉冲超声互相关流动测量系统,本系统是基于如下原理工作的:超声波穿越流动的两相流体时被流体进行了随机幅值调制。这一新的系统完全消除了连续式超声波会出现的“驻波”干扰,这种干扰导致互相关流动测量系统的性能恶化。作者还在文中给出了利用脉冲超声系统同时测定液相流速及气相流速的原始实验数据和结果。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

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。     

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.     

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

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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     

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