一种基于单片机的计算机控制逆变电源软件设计

设计基于单片机AT89C51为核心设计而成的逆变电源。文章简述了系统中电压信号处理电路AT89C51的设计方法，同时，系统的软件设计采用汇编语言，对单片机进行编程实现各项功能。程序是在Windows XP环境下采用HK-51系列仿真开发系统编写的，可以对键盘输出的信号进行采集控制。     

微型打印机通用打印程序的设计

以TPμP—16微型打印机为背景，设计了与51系列单片机的硬件接口及微型打印机字符库的扩展，重点介绍了用keil c51设计微型打印机通用打印程序的方法，此方法也适合于其他微型打印机．     

基于Small RTOS51的加速溶剂萃取仪器的研制与开发

介绍基于嵌入式实时操作系统Small RTOS51的加速溶剂萃取仪APLE2000设计的工作原理，硬件的组成和功能，嵌入式操作系统的选择以及使用Small RTOS51进行软件设计的过程，包括任务的划分、信号量的使用及驱动程序的设计等，给出应用Small RTOS51嵌入式操作系统设计的加速溶剂萃取仪器的试验数据。     

89C51单片机USB接口的设计与实现

为了解决89C51单片机与外设通信的局限性，实现了基于89C51单片机的USB接口。文章简单介绍了USB接口芯片PDIUSBD12，详细介绍了89C51单片机与PDIUSBD12的硬件连接以及固件程序、驱动程序，应用程序的设计。     

基于89C51弹奏电子琴的设计

本文主要阐述利用AT89C51单片机实现可弹奏电子琴的的设计，包括AT89C51的最小系统，矩阵键盘的设计，显示模块的设计以及音符产生的原理和实现，调试效果较好。     

功率因数的自动跟踪检测与补偿

将89c51单片微机应用于电力系统功率因数自动控制，设计中巧妙地利用了差动式相敏放大器检测电路和充分合理地使用了89c51单片机片内RAM，使电路结构简单，抗干扰性强．     

基于单片机的交通灯控制系统的设计

本文旨在设计一个基于89C51单片机的交通灯控制器。该控制器能够通过对十字路口交通灯显示状态的控制达到维持交通秩序的设计目的。系统以89C51单片机为核心，通过控制8279、数码显示管、发光二极管实现交通灯的设计功能。本设计方案简单有效，功能全面，且节省成本，有实际运用价值。     

基于89C51的自动收费系统

介绍所设计的一个基于89C51及TSOP1738的临时停车场自动收费系统，该系统通过单片机89C51控制红外接收端和计、收费端，较为理想的解决了临时停车门禁、计费及收费的功能。     

用80C51和SED1335实现LCD模块的控制

本文针对DMF50081的主要特点，提出了一种基于80C51和SEDl335的控制方法，并给出了相应的软硬件设计，为设计各种工控机的显示终端提供了一种有效途径。     

正弦函数在单片机中的一种计算方法

本文详细论述了在 MCS-51单片机中，计算正弦函数的原理、步骤、设计方法，并且给出了全部程序.     

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.     

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