机枪遥控武器站锰铜基阻尼合金缓冲器非线性有限元分析及试验

机枪遥控武器站缓冲器存在能量吸收率低、二次冲击、刚度过大等现象，导致枪口振动加剧，影响射击精度. 针对上述问题，本文基于锰铜基阻尼合金开展新型缓冲器的设计研究. 对锰铜基阻尼合金广义分数阶Maxwell本构模型进行有限元实现，开展锰铜基阻尼合金悬臂梁振动特性实验验证子程序正确性. 采用遗传优化算法设计了8片对合组合和24片复合组合两种新型阻尼合金碟簧缓冲器，进行非线性瞬态有限元分析发现24片复合组合碟簧缓冲器效果较好，相对原矩形圆柱弹簧缓冲器的振动加速度有效值可降低66.42%. 最后通过缓冲器静压试验和落锤试验验证了仿真分析结果. 静压试验表明3 kN时24片复合碟簧静态能量吸收率可达37.1%，落锤试验表明其平均动态能量吸收率为63.64%，是原矩形圆柱弹簧缓冲器的1.51倍，最大位移为2.69 mm，相对原矩形圆柱弹簧缓冲器降低30%.      

深亚微米集成电路中的连线分割和缓冲器插入

为在一定的时间限制下得到最少的缓冲器插入数目和连线分段数目，提出了一种深亚微米电路设计方法。该方法通过将传统的可变尺寸驱动连线模型改为缓冲器连线分段模型，得到了最优的缓冲器插入数目和连线分段数目。实验结果表明，在不同的时间限制下，缓冲器数目和连线分段数目是不同的。     

CMOS输出缓冲器瞬态行为的SPICE建模

根据CMOS输出缓冲器的特性，提出了一种新的输出缓冲器瞬态行为的SPICE建模方法。在把输出缓冲器的瞬态行为特性分为中间状态和稳态2种工作状态的基础上，利用IBIS模型数据，构造了SPICE的瞬态行为模型。仿真中采用TYP、MIN和MAX3种输出模型，完整地反映了输出缓冲器的特性。最后，通过比较PSPICE软件与SigXplore软件的模拟结果，验证了该方法的有效性。     

可变阻抗滑动轴承静态特性的试验研究

通过试验，探讨了可变阻抗滑动轴承的凹槽与缓冲器对轴承的承载力和静态工作特性的影响，结果表明，凹槽与缓冲器并不影响轴承的承载能力和运行位置．     

一种新型冲击吸收器：——液力空气弹簧缓冲器的研制

研制开发了一种新型的冲击吸收器－－液力空气弹簧缓冲器。介绍了液力空气弹簧缓冲器的设计思路、工作原理、结构特征及性能特点，在落锤式冲击试验机上对该缓冲器进行了冲击试验，结果发现，其动态性能良好，且具有令人满意的稳定性及复位能力。     

基于VHDL的循环缓冲器设计

循环缓冲器在实现移位运算中具有独特的优点，在滤波器的实现中使用循环缓冲器可以减少存储器读取操作，极大地提高运算的效率。本文使用硬件描述语言VHDL设计了一个功能灵活，应用方便的循环缓冲器，使用EPGA Express对描述进行了综合。结果表明系统硬件开销上，最高工作频率接近60MHz，可满足高速信号处理的要求。     

摇臂式起落架初始设计方法研究及性能仿真

建立摇臂式起落架的动力学方程。分别利用压缩比和气体状态方程对缓冲器填充参数进行预估。利用LMS V irtu-al.Lab Motion和LMS Im agine.Lab AMES im的联合仿真技术,对缓冲器性能进行虚拟落震试验。结果表明:采用气体状态方程预估的缓冲器参数,比采用压缩比预估的缓冲器参数更有效;对缓冲器油针截面尺寸优化,缩短了缓冲器行程,提高了缓冲器效率,降低了缓冲器重量。     

关于车钩缓冲装置检修方案的探讨

本文介绍了有关内燃机车检修车钩缓冲器装置的方案，机车运行时经常发生车钩缓冲器失效的情况，造成机车平稳性和安全性能下降，必须进行分解更换，这需要比较长的检修时间，制约了内燃机车的使用效率。我们通过自行设计制作检修专用工具和设备，采用简单实用的检修方法，成功快速地更换了车钩缓冲器，为内燃机车运输生产赢得大量时间。     

应用于HDTV的一种有效码率控制算法

给出了一种结合码字预分配和直接缓冲器控制的码率控制方法。这种方法主要根据不同图象的性质对各图象按目标码字进行预分析，并使压缩时码字昼与此相符，但在缓冲器接近溢出时则相应加强缓冲器控制，为使图象质量在帧内和帧间保持平稳，这里将压缩产生的码字与分配码的差，分为性质不同的帧内余量和帧间余量分别处理并控制量化级的变化。     

弹簧操动机构缓冲器仿真模型及缓冲性能改进

根据高压电器中弹簧操动机构缓冲器的工作原理,建立了缓冲器仿真模型,介绍了缓冲器仿真的方法和步骤。针对产品生产试验中出现的缓冲问题,提出了缓冲器缸体阻尼孔结构的修改方案,对比分析了缸体修改前后的特性曲线,并对新缸体进行了试验跟踪。结果显示,通过修改缓冲器缸体阻尼孔结构,提高了缓冲器的缓冲性能。     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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。     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with