计及转子阻尼效应的定子谐波漏抗

给出考虑转子谐波对定子谐波的阻尼作用时,鼠笼式异步电动机定子绕组谐波漏抗的计算方法.这一方法在参数计算准确度方面优于传统方法;同时对变极调速异步电动机,当其定子磁势谐波含量比正规绕组较大时,其电磁计算尤为重要。     

变压器运行时异常现象的分析与判断

根据变压器在运行时发生的各种异常现象，有针对性地提出了识别和判断危险源的有效方法，以便防患于未然。     

倍频变压器谐波磁场的分析与漏感抗的计算

提出了一种基于谐波平衡有限元算法的铁磁型倍频变压器等值漏电感的计算方法。计算了不同匝数、结构对漏电感的影响，并与测量值进行了比较，计算值与测量值基本一致，验证了漏电感算法的正确性，为设计、研制高效率的铁磁型倍频变压器提供了一种有效的分析方法。     

配网谐波监测及治理

随着工业的发展,客户用电量的不断增长,谐波的影响和危害也日益严重。谐波对电网造成了严重的谐波污染,并对该处的所有用户造成损害,谐波是导致电力损耗增加,供电质量下降的重要因素,谐波超标,会严重威胁配电系统的安全稳定运行,必须采取有效的手段,避免或补偿已产生的谐波。本文对鄞州的变电站和部分大用户企业进行谐波测量和统计分析,提出谐波监测、治理等方面的管理方法。     

“星丸漏”的复原研究

根据元代初期的资料，对古代计时器“星丸漏”的构造、运用作了复原研究。对星丸漏的起源进行了推测。     

供电系统中谐波电压和谐波电流的测量

本文讨论供电系统中谐波电压和谐波电流的测试技术。並讨论“电力系统谐波管理暂行规定”中有关谐波测量的一些问题。     

如何加强谐波的治理

本文针对谐波的产生以及电力谐波的危害及谐波的治理进行阐述、分析，有助于大家提高认识，积极的进行谐波治理。     

漏钢预报系统在第二炼钢厂连铸的应用

漏钢预报系统保证连铸系统正常生产，避免事故漏钢，减少漏钢损失。     

电力系统的谐波分析与测量

电力系统谐波污染日益严重,由于谐波的危害,已严重影响到电力系统的正常运行,为了维护电力系统的正常安全运行,分析和测量谐波势在必行。采用谐波分析仪对各种负荷产生的谐波进行测量、分析,目前大多数谐波分析仪都采用快速傅里叶变换FFT算法。     

铝行业谐波污染及防治

铝工业中含有大量的整流装置和非线性负荷，是电力系统中公认的谐波污染大户。其产生的谐波将流入电网，对整个电力系统的电气运行环境造成污染，使系统电压和电流波形畸变，严重影响电力系统的供电质量和安全经济运行。研究谐波现象，消除谐波带来的不利影响，不仅对于整个电力系统作用重大，而且对于铝厂自身也具有极其重要的意义。     

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).     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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