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针对双积分式A/D转换器对信号转换速率的要求不是很高而对转换精度要求很高的特点,分析了双积分式A/D转换器ICL7135与单片机的几种接口电路.对并行与串行两种方式进行说明:并行接121电路中根据占用单片机I/O端口数量的不同给出了9线制接法和改进的6线制接法;在单片机的I/O端口特别紧张的情况下,则可以采用串行接口电路.设计双积分A/D转换器ICL7135与单片机的几种接121电路,具有简单可行,有效灵活的特点.为从事单片机设计和智能仪表开发研制的人员提供了一定的参考. 相似文献
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BCD码拨盘是智能仪表和微机控制装置常用的数字设备。本文将4片BCD码拨盘同8098单片机连接,成功地应用于医药工业玻璃管同步切割系统中,用以预置玻璃管的切割长度。介绍了BCD码拨盘与8098单片机接口的硬件和软件设计。 相似文献
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串行显示驱动器MC14499及其在单片机系统中的应用 总被引:1,自引:0,他引:1
程宇红 《湖南文理学院学报(自然科学版)》2002,14(2):38-39,61
MC144 99是一种BCD码输入 -十进制码输出的串行显示驱动器 .在单片机显示系统中 ,它占用的I/O口线少、单片控制显示位数多并且使用方便可靠 ,得到了广泛应用 .文章介绍了MC144 99的性能特点及其典型应用实例 ,包括通用接口电路设计、显示驱动程序设计及巧用MC144 99DP段构成特殊显示电路的方法、使用技巧等 相似文献
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介绍一种C505CA单片机与AT机通键盘的新的接口电路,该接口电路既能接收AT机键盘的接通码,也能接收断开码,又不占用单片机的串行口。 相似文献
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文中介绍一种实用振动微机检测及监控系统,提出了一种ICL7106双积分ADC与单片机接口的数显段码信号的传输与识别系统的方案及应用电路。 相似文献
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本文以8421码为例,从电路分析,以及软件设计这几个方面出发,探讨了单片机的四位BCD编码器设计。研究表明,该电路引出的BCD编码器在连接其他电路时,非常方便。同时,在该电路的基础上,还可以对编码器的位数进行扩展。因此,单片机的四位BCD编码器电路设计功能非常强大,值得推荐。 相似文献
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电阻炉多点温度监控系统设计 总被引:2,自引:0,他引:2
李敏 《辽宁工程技术大学学报(自然科学版)》2001,20(1):71-73
以单片机为核心,利用ICL7135A/D转换的BUSY信号及多路开关,对电阻炉内多点温度进行监测;针对热电偶电热与温度间的非线性关系,设计了热电隅测温的通用查表法。本系统测温精确,节省资源,可靠实用。 相似文献
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999天以内可预置倒计时器电路主要由电源电路模块,日脉冲发生器电路模块和999天倒计时显示电路模块等部分组成。采用可预置BCD码加减计数器CD40192、三位数码管显示输出。 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献
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《上海师范大学学报(自然科学版)》2014,(5):550
<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 相似文献