模拟量光电隔离电路

光电隔离是系统抗干扰的一种重要措施。但模拟量光电隔离却一直没有得到很好地解决。本文利用Ｖ／Ｆ和Ｆ／Ｖ转换技术巧妙地解决了这一问题。实验证明，该电路具有输入电压范围宽，线性度好，准确度高的优点。     

四光耦线性隔离放大器原理及实验研究

应用普通运算放大器LF353和普通光耦TLP521设计了一种新型线性隔离放大器．介绍了设计方案及其电路结构，并分析了其工作原理．实验结果验证了本设计方案的正确性．和同类放大器比较，该隔离放大器除了在性能上和集成模拟隔离放大器相接近外，还具有电路结构简单、易于实现、造价低廉等优点．     

光电隔离的ISA总线至STD总线转换电路

介绍一种光电隔离的总线转换电路.通过它,实现ISA总线对STD总线的驱动以及两总线间的电气隔离.详细介绍了工作原理及其应用.     

新结构多晶硅发射极光电晶体管

报导了一种以多晶硅作发射极并带有隔离环电极，工作时基区处于穿通状态下的新结构硅光晶体管，用多晶硅作发射极比同结构单晶硅晶体管的光电增提高了２倍；隔离环电极极大地提高了器件的灵敏度；穿通型的工作状态提高了器件的增益和响应速度，已研制成的这种新型结构的光电晶体管在１０Ｖ工作电压下，对０．８μｍ，０．１７４μＷ的光增益达到了３８３。     

计算机控制系统与主电路隔离的几种方法

为了保证计算机控制系统运行的可靠性,一般情况下都考虑将其与主电路隔离。本文介绍了三种采用光耦合隔离的方法。与传统的方法比较,它们具有体积小、能简化电路、抗干扰能力强等优点。这些隔离方案均已用于科研中,并取得了良好的效果。     

光电隔离抗干扰技术及应用

在电子电路系统中,不可避免地存在各种各样的干扰信号,若电路的抗干扰能力差将导致测量、控制准确性的降低,甚至产生误动作,从而带来破坏性的后果。因此,若硬件上采用一些设计技术,破坏干扰信号进入测控系统的途径,可有效地提高系统的抗干扰能力。事实证明,采用隔离技术是一种简便且行之有效的方法。隔离技术是破坏“地”干扰途径的抗干扰方法,硬件上常用光电耦合器件实现电→光→电的隔离,它能有效地破坏干扰信号的进入,可靠地实现信号的隔离,并容易构成各种功能状态。     

线性光耦合隔离放大器LIA100的应用

摘要：介绍了线性光耦合隔离放大器LIA100的结构、工作原理以及它在模拟电路隔离中的几种应用。尤其详细分析了它在光电压工作模式下的工作原理和一些电参数。     

光电耦合器在微机控制系统中应用与实现

本文根据微机控制系统应用于生产过程，其环境恶劣，来自于外部干扰多的特点，提出了应用光电耦合器件实现开关量输入／输出，前向通道，后向通道等的隔离方法，并作了较详尽地讨论和说明。经在多项科研成果中应用，均取得了满意的效果。     

一种光耦隔离电路及其在并网逆变器中的应用

介绍一种由普通光电耦合器设计而成的新型光耦隔离电路,它能较好的隔离输入输出信号,抑制串入的干扰噪声.该光耦隔离电路采用差分法和偏置法,具有结构简单、线性度好、成本低等优点.详述了该电路各部分的作用,并将其应用到三相并网逆变器中做了相关实验,实验表明该电路具有精度高、稳定性好等特点,验证了理论分析的正确性.     

CCD信号的高速A／D转换及数据采集系统

研制了一个可以对ＣＣＤ信号实现高速数据采集的系统，该系统由８０３１单片机控制，采用频率可调的ＣＣＤ驱动电路、高速视频Ａ／Ｄ转换器以及总线隔离技术，实现对ＣＣＤ信号的数据采集和处理，该系统不同于ＤＭＡ系统，结构简单、价格便宜、适用范围广。     

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).     

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.     

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.