防振包装设计原理

本文在介绍隔振理论的基础上,系统探讨了防振包装设计的类型,一般设计步骤,设计参数的选择,以及单层、双层、多自由度隔振垫的设计等若干问题。文中附有多个设计实例,有助于对探讨问题的了解。     

一款室内变压器双层隔振装置的原理、设计与实验

针对居民小区中室内变压器的隔振降噪问题,以双层隔振系统的基本原理为基础,设计了一款用于室内变压器的双层隔振装置。结合干式变压器特点,给出了质量比、刚度比以及阻尼比等影响隔振效果的参数的参考取值范围,引入了隔振效果折减系数用来描述基础非刚性等因素对隔振效果的影响,并给出了对此装置隔振效果的预测范围。在实验室内用不同的上层质量对装置的隔振效果进行测试,测试所得的传递率曲线基本处于预测效果范围内,初步验证了此种设计方法的可行性,为小区配变电站的减振降噪设计提供了有益参考。     

钻柱隔振理论及钻井效率分析

应用有限元法建立了钻柱隔振的力学模型，对钻柱进行了纵向振动的动力响应分析和固有频率计算，比较了常规钻柱和隔振钻柱钻头处的位移、井口处的位移以及钻压的变化．钻柱隔振后，其固有频率远高于常规钻井时的激振频率，因此隔振后的钻柱可以避免发生共振现象，提高钻井效率．钻柱隔振理论可以为隔振器的设计和应用提供可靠的理论基础．     

双级隔振器系统参数选择的研究

研究双级隔振系统参数变化对隔振效果的影响，通过双级隔振器的隔振率分析，采用数值计算比较和理论分析确定了两种情况下隔振率与系统特征参数的关系，并对积极隔振的各种情形提出了特征参数的选取原则和物理参数的确定方法，并得出了频率比在各种情况下与隔振率的关系。为隔振器的设计提供理论根据。     

有源隔振系统传递率数值计算方法研究

研究了有源隔振系统传递率数值计算的一般方法，克服了传统解析法适用范围小的缺点．对于各种复杂的有源隔振系统，利用它可以方便地求出系统的传递率．这不仅可为引力波探测中隔振的研究提供指导，也可用于其他领域的隔振实验．     

破碎机基础隔振设计与分析

根据鄂式破碎机的产品说明书，其钢筋混凝土基础配重应该为机器质量的8～10倍．但在本工程实际建设过程中因为现场原因等未能达到要求，致使振动能量向周围传播引起振动公害．为此设计了主动隔振方案，制作一隔振用机器台座，下设隔振器．施工结束后进行现场测量振动加速度有效值及占优频率，计算的振动级VL低于ISO标准中建筑物内人体振动容许值，减振效果达到标准要求．     

摇架式隔振系统隔振特性的试验研究

研究履带车辆动力传动装置摇架式隔振系统的隔振特性。应用动力学相似理论设计制作了摇架式隔振系统的试验模型并进行了理论分析和试验。试验表明,摇架式单层隔振系统的传递率下降斜率为１２ｄＢ／ｏｃｔ,双层隔振系统的传递下降斜率为２４ｄＢ／ｏｃｔ。     

遗传算法在声纳隔振模块参数优化方面的应用

声纳在军工和民用上都有极其广泛的应用。为了提高声纳的工作性能,必须在声阵模块前、后插入性能优良的隔振模块,而隔振模块的性能参数又严重影响了其隔振性能。因此在建立隔振模块数学模型,准确计算和预报其隔振性能的基础上,进一步实现优化,对于设计和制造性能优良的声纳隔振模块,具有特别重要的意义。本文应用ANSYS软件建立了隔振模块的参数分析文件,结合遗传算法实现了充油密度、护套弹性模量、隔振组件弹性模量的优化设计。     

随机激励下四自由度机床隔振系统的主动控制研究

针对精密机床的振动问题,建立了四自由度隔振系统的动力学模型,阐述了隔振模型动力学方程的建立原则和方法,根据隔振系统的动力学模型设计了PID主动控制器,并以随机地面模型作为输入在Simulink中对其进行了仿真分析,仿真结果表明具有PID控制器的主动隔振系统在隔离振动方面效果明显优于被动隔振系统．     

舰载小尺寸隔振器的优化设计

介绍隔振器设计概况及被动隔振系统的隔振与隔冲力学模型,讨论并通过实例阐述了舰载小尺寸隔振系统在优化设计中的目标函数以及约束条件的确立方法和原则,建立了以最大隔冲响应加速度为目标函数以隔振要求为约束条件的求解优化数学模型．     

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.     

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。     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that