硅单晶热稳定性研究

本文对N型(111)高阻、P型(111)和N型(100)低阻硅单晶,进行了热处理实验,研究了氧含量和热处理温度对无位错硅单晶的电阻率、寿命和红外吸收特性的影响,确定了影响电阻率稳定性的氧含量值。     

用电火花技术制作P型高阻硅的欧姆接触

检测高阳硅单晶材料的杂质补偿度和迁移率时,必须要有良好的欧姆接触。本文提出用银头烙铁将多元合金(InBAlNi)涂敷在P型硅片上,经电火花放电技术可对电阻率高达1000Ωcm的样品制成欧姆接触。通过电流电压特性、接触电阻率和离子探针的测量,讨论了欧姆接触的机理和载流子输运的特征。电火花技术使多元合金与高阻P型硅样品在电容器放电的瞬间所产生的高能量作用下,交界面处的硅与合金相互熔融,冷却时,电活性受主元素又以高浓度析出,使原来的高阻硅变为P~ ,形成了欧姆接触。不同温度的接触电阻率测量,结合与掺杂浓度关系的计算表明,穿过金属与半导体硅接触的电流输运是热离子场发射机理,载流子隧穿势垒是主要的输运过程。     

4英寸<100>区熔硅单晶生长研究

在原有3英寸100区熔硅单晶生长工艺的基础上,通过适当的调整热场和生长参数,成功地在德国CFG4/1400P型区熔单晶炉上生长出了4英寸100晶向的区熔硅单晶,满足了对大直径100区熔硅单晶生长的需求。所生长的100晶向的硅单晶具有机械强度高、径向电阻率均匀性好的特点。     

微波光电导衰退测量少子寿命的新方法

少数载流子寿命是半导体材料的一个重要参数,它对各种半导体器件的电特性有很大影响.已有许多作者采用微波方法测量半导体材料的少子寿命.这种方法本质上是光电导衰退法.由于可做到无接触测试,它显示了较大的优越性.但是,为了把样品     

P-N~ -N-P锗漂移型三极管低频h参数的温度关系

样品的描述本工作测试了P-N~ -N-P锗漂移型三极管低频h参数的温度关系.所采用的样品是在高阻的N型锗基片上扩散一层强N型层,然后用合金方法在锗片两面制成P型区的发射极和集电极,其结构示意图如图1所示.     

场控变阻材料在高压陶瓷电容器边缘电场改善中的应用

利用场控变阻材料电阻率随电场变化的特点，改善留边型平板高压陶瓷电容器电极边缘的电场，可以大幅度提高陶瓷电容器的性能，探讨了ＰｂＯ－Ｂ２Ｏ３－ＳｉＯ２系玻璃加入掺杂ＺｎＯ制成的半导体玻璃釉对陶瓷电容器电击穿强度，充放电寿命的影响，通过配方，工艺、电极结构的优化可以使留边型高压陶瓷电容器的击穿强度提高８０％以上，充放电寿命提高了１０倍以上，并与具有类似场控变阻性能的半导体漆作了对比。     

单晶硅力学性质探索

本文的目的在于研究n型和p型硅单晶材料在外荷载作用下的变形性质。将云纹干涉和散斑干涉技术用于硅单晶材料变形性质的测定。试验结果表明,当载荷值小时,其变形量增大,而当载荷增加时,其变形增长量减小,这一现象证实了在硅晶体中存在着弱结合空位层,在外载荷作用下,排出晶体中的空位,致使晶体增密,或者说提高了硅单晶的密度所致。     

韧性材料疲劳寿命曲线经典表达式的改进

根据有平均应力情况下的韧性材料疲劳寿命曲线的变化规律，建立了韧性高次循环疲劳寿命起始点Ｎｓ与平均应力σｍ之间的关系式，从而改进了韧性材料疲劳寿命曲线的经典表达式，这对韧性材料的疲劳寿命的正确计算是很重要的。     

低氧单晶硅工艺研究

一、引言 硅单晶中的氧在不同温度下以不同的组态存在,而不同组态的氧对材料电学性质的贡献又各不相同。在器件制造过程中,硅单晶要通过氧化、扩散、烧结等工艺过程,由于都是在高温(1000～1200℃)下进行,所以材料原来测定的电阻率和寿命等参数,都将发生很大的变化。这样,半导体器件的特征值,如P-N结的击穿电压、电流放大倍数与电流的关系、     

多线切割工艺断线问题的分析

在多线切割工艺中，镀铜金属线对硅单晶切割片的质量有着重要影响，成为多线切割工艺需要控制的重要辅料。断线问题一直是困扰多线切割工艺人员的主要问题之一，一直得不到有效的解决，本文从材料、设备、工艺以及人员等多个视角对断线问题进行了分析，并给出相应的解决措施。     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the