高精度非球面制造系统控制软件的设计

根据高精度非球面制造及测量的需求,设计并实现了高精度非球面制造及测量系统的控制软件．系统基于工控PC机和Windows98操作系统,并选用Delphi6．0和Visual Fortran作为开发工具．系统采用在线误差补偿加工技术,选择平面砂轮和圆弧砂轮两种加工方式．可达到加工高精度光学非球面镜的要求．     

小型非球面超精密加工建模及控制技术研究

根据高精度小型非球面制造的需要,探讨了一种针对小型非球面元件的加工方法,并分析了实现数控加工控制的技术途径.根据非球面加工理论,基于工控机和Windows系统,用VB.NET开发实现了小型非球面数控加工控制软件.     

大量程高精度非球面光学元件检测平台设计

针对目前高精度,大量程的非球面检测需求,综合考虑各部件对平台精度的影响,完成了对平台的机械系统,探测系统和运动控制系统的设计.该非球面光学元件检测平台采用花岗岩框架结构,以增加整体结构的刚度,减小自身热变形引起的几何误差.系统的探测系统采用了接触/非接触式双重测量的检测方法,既提高了测量的速度,又增加了测量数据的可靠性.运动控制系统则采用运动控制卡+伺服电机的三轴联动的开放式运动控制方式,满足了高精度非球面光学元件的检测需要.     

基于运动控制技术的非球面测量系统

为满足非球面光学元件表面精度的测量要求，设计和实现了一种高效数控非球面测量系统．系统基于运动控制技术，构建了四轴联动的测量工作平台．根据数据采集原理，实现对非球面工件表面形位参数进行连续采样．整个系统采用工控微机作为上位机非实时控制，下位机采用高速DSP进行实时控制．在Windows操作系统下，用Visaul C＋＋开发工具完成了测量系统的软件开发．最后通过实验对测量系统的稳定性及其误差进行了分析．实验结果表明，系统行程为100～120mm，系统误差小于5μm，能满足普通光学非球面元件测量精度的要求，同时系统体现了较好的通用性和可靠性．     

高精密光学元件磨床的加工与检测系统的开发

高精密平面磨床是加工光学非球面元件的一种重要途径.出于通用性和效率的考虑,开发一套面向光学非球面元件的高精密平面磨床的加工与检测系统,以此来实现光学非球面元件的精密加工.以自行开发研制的四轴数控高精密平面磨床为研究基础,采用模块化设计,选用Delphi 7为开发语言,运用Delphi 7和Matlab混合编程技术,搭建了加工与测量系统,实现了光学非球面元件的磨削加工、面形测量、磨削补偿以及环境检测等.实验结果表明,该系统可以满足光学元件的精密加工及检测,并具有较高的工作效率.     

用偏振移相共路剪切干涉仪测量光学非球面

现代光学系统中大量使用了非球面元件,光学非球面表面面形精度要求高,一般不低于λ/4(λ=0.6832μm),使得加工与检测难度极高。本文介绍了一种用于测量光学非球面透镜的偏振移相剪切干涉方法和数据处理方法,该系统具有测量精度高、调整方便、测量速度快、操作简单、对外界干扰不敏感等特点。     

高精度温度测量系统的设计

介绍了利用高精度温度传感器AD590以及LMX31系列的V/F变换芯片构建的高精度温度测量系统，并运用MAX354芯片实现了8通道的循环检测功能．对系统的测量结果运用C语言在基于单片机的平台上进行了解算．给出了一种实用的高精度温度测量系统设计，在硬件电路、元件选型以及软件设计思路给出了明确方案．经过实际应用表明，此系统实现了高精度的温度测量．     

光学非球面的超精密加工技术及非接触检测

针对亚微米级及亚微米级以下的光学硬脆性非球面器件难加工问题,分析了光学非球面的形状精度和应用,讨论了其超精密加工原理和方法及非接触检测手段．结果表明,精密数控机床、硬脆性材料延性域加工原理和超精密检测是光学非球面超精密加工的技术保证．     

基于自适应滤波的超声波高精度测距系统

超声波测距在兵器装备中具有广泛的应用,应高次非球面加工机床项目要求,超声波测距精度须达到1 mm,如何提高超声波测距系统的测量精度成为了亟待解决的问题,针对现有的超声波测距测量精度不高的特点,提出了一种基于自适应滤波算法的估计超声波渡越时间的方法,并利用现有的超声波测距经验模型,达到超声波高精度测距的目的.     

非球面及非球面测量技术

为了对非球面进行行之有效的测量,从非球面的面形描述和光学特点出发,对非球面各种测量方法进行了优缺点的对比和研究,同时对目前非球面检测技术面临的问题进行了阐述,并给出了对深度非球面测量可用的方法和应当解决的问题。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-