排水型深V船系列模型尾板减阻试验研究

针对千吨级排水型深V船减阻节能的需要，开展小系列深V船尾板减阻试验研究.尾板长度变化范围为(0.010~0.023)Lwl，尾板下反角为3°~10°，试验速度区间为Fr=0.15~0.52.基于试验数据，综合分析了航速、尾板长度及下反角等参数变化对减阻效果及船体航行纵倾的影响规律，获得了优良减阻效果的尾板设计参数及适用航速范围.     

单层流驱动超临界孤立子的数值计算

用ｆＫｄＶ模式方程对单层二维表面波进行直接的数值研究。计算得出，在共振区域先锋弧立子的生成与Ｔ．Ｙ．Ｗｕ（吴耀祖）及Ｓ．Ｊ．Ｌｅｅ等人的结果相同。在共振点与超临界转向点之间，对每一个Ｆｒ数存在初始不稳定的单峰孤立子，其振幅随时间增加。当Ｆｒ数接近共振区时，初始孤立子分裂成先峰孤立子，即先峰孤立子生成是占优的。当Ｆｒ接近超临界转向点时，这类初始不稳定孤立子最终破碎。当Ｆｒ超过临界转向点时，存在一类稳     

MOSSBAUER STUDIES OF MAGNETIC PROPERTIES AND ANISOTROPIES FOR THE HYDRIDED AMORPHOUS ALLOYS

本文使用穆斯堡尔谱研究了非晶态Ｆｅ－（Ｃｏ，Ｃｒ）－Ｚｒ和Ｆｅ－（Ｎｉ ，Ｃｒ）－Ｓｉ，Ｐ，Ｃ）合金的掺氢效应．在室温下，ａ－Ｆｅ－Ｃｒ－Ｚｒ 合金穆斯堡尔谱是顺磁谱，但是，掺氢后它们变成了铁磁谱．对于Ｆｅ－Ｃｒ， Ｆｅ－Ｎｉ，Ｆｅ－Ｃｏ基非晶态合金，掺氢使它们的磁状态和同质异能移位发 生不同的变化，这起因于在不同类型的合金中体积膨胀、电荷转移效应和键合作 用起了不同的作用．使用经典的磁偶极相互作用模型解释了掺氢对非晶态合金的 磁各向异性的影响．     

深冷处理对Cr12钢力学性能的影响

本文对Ｃｒ１２钢深冷处理后力学性能变化做了研究，试验结果表明．深冷处理可以不同程度地提高Ｃｒ１２钢的硬度与耐磨性．而Ｃｒ１２钢淬火回火后再进行深冷处理可使冲击韧性提高．同时，淬火加热温度对深冷处理效果亦会产生影响．     

添加氧化物粉末对FeCr烧结合金交流磁特性的影响

添加氧化物粉末对ＦｅＣｒ烧结合金交流磁特性的影响（日）大同工业大学和大同特殊钢公司技术开发研究所为进一步提高ＦｅＣｒ系烧结合金的交流磁特性，研究了添加ＳＩＯ。、ＣａＯ、ＡＩ。Ｏ。的粉末混合物对低Ｃ的Ｆｅ－１３Ｃｒ－０．ＳＳｉ烧结合金磁性的影响。试验用...     

Er_2Fe_(17)C_xN_y系稀土化合物Er_2Fe_(17)CN自旋重定转换温度的穆斯堡尔谱分析

在温度为２９５Ｋ～８０Ｋ范围内，应用穆斯堡尔效应方法，测量了Ｅｒ２Ｆｅ１７ＣｘＮｙ系稀土化合物Ｅｒ２Ｆｅ１７ＣＮ的穆斯堡尔谱．结果表明，用Ｃ，Ｎ原子掺杂渗入Ｅｒ２Ｆｅ１７化合物替换Ｅｒ３＋离子后形成的Ｅｒ２Ｆｅ１７ＣＮ化合物，影响了Ｅｒ２Ｆｅ１７化合物原来的自旋重定转换温度ＴＣ，并使自旋重定转换角度θ也发生了变化，出现了两个自旋重定转换温度ＴＣ１，ＴＣ２．ＴＣ１２００Ｋ，ＴＣ２８０Ｋ．这说明稀土化合物Ｅｒ２Ｆｅ１７ＣＮ磁矩是突变的（一级相变）．     

人工神经网络法预测有机物物性的研究1．亨利定律常数和水中溶解度

本文用人工神经网络方法，以ＣｒａｍｅｒⅢ的ＢＣＤＥＦ参数作为输入参数，预测有机物物性．对于１５３个不同类型有机物的亨利常数（Ｈ）的预测结果为：相关系数ｒ＝０．９８１３，标准差ＳＤ＝０．３３６９ｌｏｇＨ单位，对于９１种有机物在水中溶解度（Ｓ）的预测结果为：相关系数ｒ＝０．９８５５，标准差ＳＤ＝０．２８２７ｌｏｇＳ单位。     

400 km/h高速列车转向架底板的阻力影响数值模拟研究

采用数值仿真方法研究明线运行400 km/h高速列车转向架底板包覆结构的气动阻力影响规律,揭示不同包覆形式及安装高度、缝隙间距这两类关键构型参数的阻力影响特性及流动结构的作用特征。研究结果表明：全封一体式及分体式底板包覆方案对整体均有明显的减阻效果,最优减阻率达9.76%,以头车转向架区域为主要减阻部件,但中间车阻力有所增加,且头车包覆越完整,中间车阻力增加越明显;在不同安装高度下,底板减阻效果呈非单调变化,头车底板适当下移有利于提高整车减阻效果,其原因主要是降低了中间车的转向架阻力;当底板缝隙间距维持在一定范围内时,整车减阻效果变化不大,继续增大缝隙会导致减阻效果变差,因为过大的缝隙将显著增强气流对转向架及舱体的冲击,导致整车减阻效果降低。     

人工神经网络法预测有机物物性的研究：1.烹利定律常…

本文用人工神经网络方法，以ＣｒａｍｅｒⅢ的ＢＣＤＥＦ参数作为输入参数，预测有机物物性。对于１５３个不同类型有机物的亨利常数（Ｈ）的预测结果为：相关系数（ｒ＝０．９８１３，标准差ＳＤ＝０．３３６９ｌｏｇＨ单位。对于９１种有机物在水中溶解度（ｓ）的预测结果为：相关系数ｒ＝０．９８５５，标准差ＳＤ＝０．２８２７ｌｏｇＳ单位。     

侧喷射流的仿生鱼表面减阻优化研究

为了研究射流孔结构参数对水下射流减阻的影响,以金枪鱼为仿生对象建立仿生鱼模型,通过模拟鲨鱼鳃在仿生鱼模型侧面添加射流孔建立了射流模型.采用数值模拟方法,分析主流场速度及射流孔的形状、高度、位置、高宽比等单因素对仿生鱼表面减阻的影响规律.通过Design-expert软件对射流孔的结构参数进行响应面多目标参数优化,进一步分析了不同射流孔的结构参数在相互作用时对仿生鱼表面减阻的影响,最终确定了在距离鱼首5 mm处添加形状为后三角形,高度为6 mm,高宽比为4的射流孔时能够达到比较理想的减阻效果,此时模型的总阻力为2.510 21 N,相应的减阻率为6.49%.本文通过深入分析射流孔结构参数的影响,为水下射流减阻技术提供了重要的理论基础和实验指导,为仿生技术在水下流体力学领域的应用拓展了新的可能性.     

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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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.     

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