10 research outputs found

    Research and Realization of RTOS in Underwater Acoustic Communication System

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    在人类探索和开发海洋的过程中,水声通信技术得到了迅速的发展,已经在海洋勘探、灾难预报、水下遥控、海洋信息采集、对潜通信等领域发挥着极其重要的作用。完整的水声通信系统包括信源编解码、信道编解码、调制解调、发送接收等模块,需要复杂的软、硬件系统支持。实时操作系统能够有效管理各个硬件模块,为用户提供调用接口,可以简化软件设计,缩短系统开发周期。本文剖析了现有各种嵌入式实时操作系统的运行机制,研究实时操作系统在水声通信领域的应用,并以凌阳16位单片机SPCE061A为处理器模型,初步设计一个基于水声通信系统的专用实时操作系统UWAC-RTOS。UWAC-RTOS的系统内核包括任务管理、任务调度、中断管...With the increasing of ocean exploitation, the techniques of underwater acoustic (UWA) communications have rapidly developed, which play an important role in the fields of ocean exploration, disasters forecasting, underwater remote controlling and ocean information collecting, etc. A full UWA communication system includes several modules, such as coding and decoding of signal source and channel, s...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:20043003

    The Methods of Abstracting Chinese Dot Matrix for Embedded Systems

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    嵌入式系统人机交互性能的重要指标之一是汉字显示打印功能,利用汉字点阵实现此功能是一种简单实用的方法,因此从现有汉字系统中提取汉字点阵是嵌入式系统开发的第一步工作。提取汉字点阵有两种方法,一是从点阵字库中提取,二是从矢量字库中提取,这两种方法在实际开发工作中都得到了应用。详细分析了这两种方法的原理及编程实现,提出了自动扫描嵌入式应用程序生成汉字点阵的方法,这种方法特别适用于建立小型汉字点阵库。It′s a simple and practical method to use the Chinese dot matrix to display and print Chinese characters in embedded systems.Therefore,abstracting dot matrixes from the existing Chinese character OS is the first step of developing embedded system.We can abstract dot matrixes from the dot matrix library or from the vector library.Authors have applied both ways in practical applications.This paper analyses the principles and programming of both ways in detail.In addition,this paper proposes a method of auto-scanning source files,this method is best for creating mini dot matrix library.厦门大学985二期信息创新平台项目资

    KOH熔盐法处理低品位难分解钽铌矿的实验研究

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    首次提出采用"配矿-KOH 熔盐分解-水浸出"的新工艺来处理低品位、难分解钽铌矿。探讨了矿物铌/钽质量比、分解温度、碱矿比、分解时间和矿物平均粒径等因素对铌和钽的浸出率的影响。结果表明,在最优处理条件下,铌和钽的浸出率可分别达到95%和93%,较现行氢氟酸工艺提高10%左右,大大提高了难处理钽铌资源的利用率。用无毒的 KOH 熔盐取代现行工艺中高浓高毒性的氢氟酸作为反应介质,从生产源头削减了 F 的三废污染,为钽、铌湿法冶金开辟了一条新的途径

    analysisofmetallicelementsinrefractorytantalumniobiumslagbyicpaes

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    A new method for analysing the contents of many metalic elements, such as Ta, Nb, Sn, Ti, W, Fe, Mn, Al, Ph, Ce, Y, Sc, Pr, Sm, Nd, U, Th etc, in refractory tantalum-niobium slag by ICP-AES was developed. The samples processing procedures involve two steps, being first decomposed by potassium carbonate and boric acid at 950 degrees C for 15min, then leached by hydrochloride and tartaric acid at 90 degrees C for 30 min. The interference of flux and tin matrix in analyzing the other elements was eliminated by the utilization of matrix matching method. This method showed satisfactory precision and accuracy with the RSDs between 0.27% and 5.48% and the recovery rates between 94.0% and 109.6%. The analysis results indicated that highly valuable metals of Sn, Ta, Nb, Ti, W and Ce are rich in the refractory tantalum-niobium slag, showing that it has the great potential for comprehensive utilization. However, the analysis result also showed that the slag is a radioactive pollution source due to a small amount of U and Th. This method is simple and fast, and has the advantage of analyzing many elements simultaneously. The accurate analytic results provided a basis for the future researches on the comprehensive utilization of refractory tantalum-niobium slag

    甲醇分解铝酸钠溶液制备大颗粒氢氧化铝的工艺与表征

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    对甲醇分解NaAl(OH)4溶液制备大颗粒Al(OH)3进行了工艺研究,考察了分解温度、分子比(Na2O/Al2O3摩尔比)、Na2O浓度、硅量指数(Al2O3/SiO2质量比)、搅拌速度和甲醇用量对产品粒度和形貌的影响.结果表明,在NaAl(OH)4溶液的Na2O浓度为180g/L、分子比为1.5~1.6,硅量指数550以上及甲醇与NaAl(OH)4溶液等体积的优化条件下,控制分解温度60℃,可得到平均粒径达80μm的球形Al(OH)3.甲醇的加入改变了Al(OH)3生长基元的径向和轴向生长速率,甲醇量越大,径向生长速率越快,生长基元越薄.当甲醇与NaAl(OH)4溶液体积比为1:1时,Al(OH)3生长基元的厚度在100nm左右.随分解温度升高,Al(OH)3由Bayerite型向Gibbsite型转变,热重-差热值与理论值吻合

    ICP-AES法对铬铁矿中的多种元素进行定性与定量分析

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    采用ICP-AES法对铬铁矿首先进行定性分析,确定了铬铁矿中含有的元素种类;经过分析发现铬铁矿中含有Cr,Fe,Al,Mg,Zn,Co,Ni等29种元素。然后根据定性分析的结果,对铬铁矿中的主要元素Cr,Fe,Al,Mg,Ca,Ti,Si,Mn,V的含量进行测量。铬铁矿样品的前处理分两步进行,首先用碳酸钠-四硼酸钠在950 ℃下熔融30 min,然后用稀盐酸在80 ℃下浸取10 min,即可将样品完全溶解。实验结果表明,该方法的相对标准偏差为0.48%~2.05%,加标回收率为90.5%~111.3%,分析精确度满足要求

    KOH亚熔盐中钒渣的溶出行为

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    对钒渣在KOH亚熔盐体系中的分解动力学进行研究,考察反应温度、碱矿质量比、粒度、气流量等工艺参数对钒渣分解过程的影响,获得最优工艺参数,并对反应机理进行探讨。结果表明,反应温度是最重要的影响因素;钒渣最优浸出条件如下:在反应温度为180℃,碱矿比4:1,KOH碱浓度75%,搅拌速率700 r/min,反应时间300 min,常压通氧气流量为1 L/min的反应条件下,最终钒、铬的浸出率分别达到95%和90%以上。钒渣在KOH亚熔盐介质中氧化分解遵循缩核模型,并主要受内扩散控制,钒和铬分解的表观活化能分别为40.54和50.27 kJ/mol,钒铬尖晶石的氧化以铁橄榄石、石英相的氧化分解为前提

    KOH亚熔盐中钒渣的溶出行为

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    对钒渣在KOH亚熔盐体系中的分解动力学进行研究,考察反应温度、碱矿质量比、粒度、气流量等工艺参数对钒渣分解过程的影响,获得最优工艺参数,并对反应机理进行探讨。结果表明,反应温度是最重要的影响因素;钒渣最优浸出条件如下:在反应温度为180℃,碱矿比4:1,KOH碱浓度75%,搅拌速率700r/min,反应时间300min,常压通氧气流量为1L/min的反应条件下,最终钒、铬的浸出率分别达到95%和90%以上。钒渣在KOH亚熔盐介质中氧化分解遵循缩核模型,并主要受内扩散控制,钒和铬分解的表观活化能分别为40.54和50.27kJ/mol,钒铬尖晶石的氧化以铁橄榄石、石英相的氧化分解为前提
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