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针对SPI总线接口缺乏标准协议的特点,提出了SPI器件之间通信的一般方法。论文阐述了ARM芯片内置SPI硬件控制器的工作原理和时序,并对射频芯片TRF7960x的工作模式与读写要求进行了分析。在此基础上,根据TRF796x的时序特性和访问要求,采用ARM芯片的硬件SPI方式实现对TRF796x的读写访问与控制,并在RFID门禁系统中验证了通信结果。 相似文献
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表面致密化--一种提高烧结齿轮性能的有效方法 总被引:4,自引:0,他引:4
表面致密化与传统的粉末冶金方法相结合,可以显著改善烧结齿轮的疲劳及表面磨损性能。从而提高齿轮的寿命,同时使生产高性能齿轮的总成本降低,为用粉末冶金(PM)方法生产汽车变速箱齿轮提供了更大的可能性。本文着重讲述了使用这种方法生产高性能PM齿轮的工艺过程,同时介绍了测定致密化效果及齿轮性能的几种主要方法,并根据工艺过程比较了使用传统的机加工方法及本文所述的方法生产同性能齿轮的成本差别。最后,以两个实例分别介绍了使用上述方法对Volvo 850系第五挡变速齿轮及Scania载重车变速箱中行星齿轮的研发。 相似文献
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设计一种基于MSP430单片机的多协议RFID读写器。分析RFID概念、应用现状及系统构成,介绍两款主要芯片的功能特点,给出系统硬件组成结构.提出系统的软件组成模块及软件流程图。系统顺利通过测试,其设计达到相应的技术指标要求,具有良好的市场应用前景。 相似文献
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本文以MSP430系列的单片机为核心,提出了个人状态远程监视及语音通讯系统方案。该系统能采集个人的心率、血压和体温等生命信息,并实现对象间的无线语音通讯。 相似文献
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M. Hartmann I. Gushterova M. Fikri C. Schulz R. Schießl U. Maas 《Combustion and Flame》2011,(1):172-178
Toluene is often used as a fluorescent tracer for fuel concentration measurements, but without considering whether it affects the auto-ignition properties of the base fuel. We investigate the auto-ignition of pure toluene and its influence on the auto-ignition of n-heptane and iso-octane/air mixtures under engine-relevant conditions at typical tracer concentrations. Ignition delay times τign were measured behind reflected shock waves in mixtures with air at φ = 1.0 and 0.5 at p = 40 bar, over a temperature range of T = 700–1200 K and compared to numerical results using two different mechanisms. Based on the models, information is derived about the relative influence of toluene on τign on the base fuels as function of temperature. For typical toluene tracer concentrations ?10%, the ignition delay time τign changes by less than 10% in the relevant pressure and temperature range. 相似文献
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TRFLP在微生物群落结构与动态分析中的应用 总被引:1,自引:0,他引:1
介绍了末端限制性片段长度多态性技术(TRFLP)的基本原理和操作要点,综述了该技术在土壤、肠道、受污染环境以及污染物处理工艺微生物群落结构、动态分析中的应用.由于技术整合了自动测序仪的高分辨率和高通量特征,对分析复杂群落的结构较其它指纹技术更具有明显优势和广阔的应用前景.对于无法将特异条带进行测序分析及原位杂交的缺点,可通过与克隆文库序列进行比较,并采用软件将多酶切的末端限制性片段(TRFs)与现有数据库进行叠加比较的方式加以弥补. 相似文献
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Grigorenko Elena L.; Geiser Christian; Slobodskaya Helena R.; Francis David J. 《Canadian Metallurgical Quarterly》2010,22(4):893
A large community-based sample of Russian youths (n = 841, age M = 13.17 years, SD = 2.51) was assessed with the Child Behavior Checklist (mothers and fathers separately), Teacher's Report Form, and Youth Self-Report. The multiple indicator-version of the correlated trait-correlated method minus one, or CT-C(M ? 1), model was applied to analyze (a) the convergent and divergent validity of these instruments in Russia, (b) the degree of trait-specificity of rater biases, and (c) potential predictors of rater-specific effects. As expected, based on the published results from different countries and in different languages, the convergent validity of the instruments was rather high between mother and father reports, but rather low for parent, teacher, and self-reports. For self- and teacher reports, rater-specific effects were related to age and gender of the children for some traits. These results, once again, attest to the importance of incorporating information from multiple observers when psychopathological traits are evaluated in children and adolescents. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
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