边界扫描测试实验系统的设计与开发

根据数据域测试及仪器课程教学的特点和需要,设计了一个典型的边界扫描测试系统作为课程实验。实验系统主要由计算机、USB-1149控制器和四通道被测电路板等3个部分组成。首先介绍了系统的层次架构,然后针对自主研制的USB-1149控制器的软、硬件设计实现过程,进行了详细的描述。学生通过该实验的学习可以加深对可测性设计和边界扫描等概念的理解,领会数字系统测试和故障诊断的复杂性和重要性。     

基于可测性分析的高层次寄存器分配算法

为了提高综合后电路的可测性,提出了一种面向电路可测性的寄存器分配方案.该方案首先从已调度的数据流图着手,建立了一种可用于高层次综合的行为级可测性分析方法:对算子模块的门级实现进行门级可测性分析,并进而抽象出算子的行为级可控性/可观性值;在数据流图中,逐级计算出各节点变量的行为级可测性指标;然后按照最大改善可测性指标的原则,进行寄存器分配.在标准电路上的实验表明,除了较小的面积开销外,电路的可测性优于所对照的其他2种方法.     

JTAG技术在PCB测试中的应用

印刷电路板越来越复杂,完整的测试变得越来越重要。上世纪八十年代,联合测试行动工作组（JTAG）开发出边界扫描的测试规范,这个规范后来被制定为IEEE1149．1—1990标准。边界扫描测试结构提供了一种方法,可以高效的测试PCB上面的器件,基于边界扫描的PCB测试技术是一项成本低廉、高效、高覆盖率的测试技术,较好的满足了复杂PCB板级测试方面的需求。     

基于微机的边界扫描测试主控系统的设计

分析了边界扫描测试技术的工作机制对测试主控系统的功能需求，提出了一种基于微机PCI总线的低成本边界扫描测试主控系统的硬件设计方案，该系统以PC机为平台，以用CPLD器件实现的JTAG主控器生成满足IEEE1149．1协议的边界扫描测试信号，并用普通的SRAM实现存存器共享，仿真表明，该系统产生的测试信号完全满足IEEE1149．1协议的时序要求，可用于IC和PCB的边界扫描测试，以及改进边界扫描测试的研究和实验。     

802.11b MAC子层控制器的设计与验证

IEEE 802．11b协议是目前运用最为普遍的无线局域网标准．基于独立组网模式,对介质访问控制层进行VLSI设计,并可方便地扩展为适用于骨干网模式的设计．设计的特色是采用了事件响应的设计路线以达到低功耗的目的;采用了基于内部总线共享的双总线系统架构,结合一种新颖的基于总线监控的调试方式,增强了设计的可测性,降低了验证成本,缩短了设计周期。     

一种JTAG主控器芯片的改进设计与逻辑实现

提出了对JTAG主控器的一种改进方法，并在逻辑上实现了这一改进。改进后的主控器可以提供连续寻址16B存储器页空间的访问方式，从而为测试软件程序员提供了良好的平台。仿真表明该芯片通史提供满足IEEE P1149。1协议的测试信号。     

JTAG标准及其与16位微处理器IP软核的集成

随着集成电路规模的越来越大,可测性设计越来越受到业内的关注,基于JTAG标准的可测性设计是当前的研究热点之一;文章首先介绍了JTAG标准,进而详细讨论了JTAG模块的设计、与16位微处理器IP软核的集成方法与实践;然后介绍了一种模块化设计的方法,具有较强的实用性和可移植性.     

JTAG边界扫描单元的改进方案

首先分析了边界扫描系列协议的现状，指出近期的工业标准仍将只有IEEE std 1149．1．为了能够检测电容耦合故障，对JTAG规定的边界扫描单元进行了简单的修改．修改之后的扫描单元在不影响JTAG定义功能的同时，增加了对耦合电容的故障检测能力．     

最新WLAN协议IEEE802.11g物理层性能分析

新制定的IEEE802.11g协议标准是最有发展潜力的无线局域网标准.在全面介绍了IEEE802.11g物理层的各项参数后,分析了IEEE802.11g系统性能和吞吐量性能,并给出了相应的系统性能仿真结果,其结论对今后的IEEE802.11g系统的深入研究具有重要参考作用.     

全自动洗衣机多功能教学实验仪的设计与实现

介绍一种自主研发的全自动洗衣机多功能教学实验仪.该教学实验仪设计时以教学实验过程中操作的安全性、简洁性、方便性为重点,让学生更加容易地掌握全自动洗衣机的结构、原理及常见故障检修.利用本仪器不仅可以完成洗衣机相关教学,而且可以作为学生实验实习和技能考核的工具.     

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