生物液膜振荡器中的振动共振

通过数值模拟的方法研究了生物液膜振荡器在高、低两种不同频率信号作用下的振动共振现象。结果表明：体系线性响应随高频信号振幅的变化发生了多重振动共振,且低频信号的频率越低,系统的多重振动共振强度越大。体系线性响应随高频信号频率的变化可以发生高频频率依赖的多重振动共振,体系对大振幅低频信号的放大程度要比小振幅低频信号大;低频信号频率越低,系统的高频频率依赖的多重振动共振强度越大。通过负反馈机制可以有效调节体系多重振动共振峰的个数和高频频率依赖的多重振动共振的强度。当低频信号的频率等于高频信号的频率时,体系可以发生类频率共振强化的振动共振。     

超声扭转振动系统局部共振的有限元仿真研究

应用有限元方法，对超声扭转振动系统局部共振做出仿真研究．分析了阶梯形变幅杆谐振频率随粗细端长度及截面直径比的变化规律．结果表明，局部共振不仅与粗细端直径比有关，还与两段杆的长度有关．将长度比控制在一定范围内，可使系统谐振频率更接近于四分之一波长细杆的谐振频率．在实际应用中，可适当设计两端长度比，使系统更好地工作于局部共振状态，这对实际振动系统的设计具有一定意义．     

研究和技术简报简单机械元件自然频率的共振测定法

本法的原理是众所周知的,就是:当一个强迫振动系统发生共振时,振幅最大,而且这时的外力频率等于系统的自然频率。如果共振时外力频率是已知的,那么,系统的自然频率就知道了。本文报导作者的实验。     

一类非理想振动系统的回转频率俘获特性

定量揭示了非理想振动系统起动过程中的一种特殊物理现象——回转频率俘获．比较分析了回转频率俘获与迟滞共振及传统频率俘获的动态行为差别，通过简化自同步振动非理想系统的力学模型，从一般意义上揭示了系统阻尼变化导致非理想系统稳态转速变化的规律，提出了通过增大系统阻尼避免回转频率俘获的实用策略．     

肺胸系统时变频率特性研究

应用自回归（ＡＲ）模型方法，对正常肺胸系统与支气管一气管系统进行了建模分析，研究了上述两系统的时变幅频特性，实验结果表明：正常肺胸系统有一个共振峰，其共振峰频率随时间变化，系统可建模为一稳定的６阶线性ＡＲ滤波器，正常支气管一气管系统有２－５个共振峰，其系统可模拟为一稳定的１４阶线性ＡＲ滤波器，ＡＲ建模方法是肺胸系统分析的有效方法。     

结合数字滤波技术的随机共振弱信号检测

应用数值计算研究强噪声背景下弱信号的随机共振检测. 探讨了大频率条件下非线性双稳态系统随机共振的输出信号幅值、 信噪比与随机噪声的关系, 数值计算结果表明, 非线性双稳态系统对大频率噪声具有较大的压制特性, 通过随机共振系统可以检测强噪声背景下的大频率弱信号. 结合数字滤波技术提取了大频率弱信号, 并获得被检测大频率弱信号的特征频率谱线及时域图像.      

基于磁耦合共振的无线能量传输特性分析

为了提高磁耦合共振系统的能量传输效率,通过研究系统无线能量传输特性,探索了系统传输效率随耦合距离变化的规律。基于二端口网络分析方法,建立了磁耦合共振无线能量传输的等效电路模型,求解出共振系统发生频率分叉现象产生的条件以及最大效率时的频率表达式。通过数值仿真对共振系统传输特性进行了分析,揭示了系统的固有共振频率会随着耦合距离的增加,由两个相差较远的共振频率逐渐靠近,直至跨越临界条件,汇聚为一个共振频率的规律。实验结果与理论分析吻合,所建理论模型能够准确描述整个共振系统的能量传输特性。结论可为优化磁耦合共振无线能量传输系统工作效率提供理论依据。     

机械支座激扰的减振新探讨

在支座激振的机械振动的理想模型下，讨论激扰频率为时间的函数的工程实际，在系统接近共振区时通过采取改变系统弹性刚度的措施，减小这类系统经过共振区时的受激振幅。并用Matlab对这种减振效果加以仿真分析。     

频移随机共振在信号检测中的应用

基于傅立叶变换的频移特性，探讨了双稳态系统中的高频随机共振现象.仿真结果表明，将输入信号的大频率移动到一个小频率后，双稳态系统的输出功率谱在此频率处的值得到明显增强.在一个较大的频率范围内检测强噪声背景下的弱信号的能力大大增强.     

两种阻尼模型对结构动力特性影响的能量分析

采用能量分析法，对基于线性阻尼模型和能量型非线性阻尼模型的结构共振特性和地震响应进行研究，通过对一柱状结构的计算分析，得出结论：对于线性阻尼模型，当激励荷载的频率与结构系统自振频率很接近时，结构的能量响应会出现非常大的突变，即存在能量共振；对于能量型非线性阻尼模型不存在能量共振，且能量型非线性阻尼模型具有较强的抗震耗能能力。     

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).     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.