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11.
ST7920点阵式液晶显示模块的应用研究和编程 总被引:1,自引:7,他引:1
介绍了基于ST7920控制器、内嵌汉字库的点阵式液晶显示模块,给出了ST7920与单片机之间的硬件接口设计,阐述了液晶模块文本显示模式和绘图显示模式的各自特性和实用方法,通过由C语言编写的生动的程序演示实例来揭示点阵式液晶显示模块个性化中文菜单的开发过程,重点介绍了菜单设计中的反白问题的两种实现方案。与不带汉字库的LCM模块相比,ST7920省略了取字模过程,软件控制非常方便。 相似文献
12.
Lan Luo Ziyi Zhang Yanhua Chen Lixia Zhang Xiangfeng Bu Hanqi Zhang 《International journal of environmental analytical chemistry》2017,97(12):1178-1191
A simple and sensitive surface-enhanced Raman spectroscopy (SERS) method for the detection of safranine T (ST) and Hg2+ using silver nanoparticles (AgNPs) as substrate was developed. ST can absorb on the surface of AgNPs through electrostatic interaction, the electromagnetic effect combined with chemical adsorption effect give a notable Raman enhancement for ST. The presence of Hg2+ well decreased the absorbed ST molecules on AgNPs, leading to a significant decrease of SERS signals thus enabling to detect Hg2+. The determination conditions for SERS, including the amount of AgNPs, the concentration of NaCl, the concentration of HCl, the concentration of ST and the reaction time, were optimised. Under the optimised experimental conditions, good linear responses were obtained for ST and Hg2+ in the concentration ranges of 0.01–4.0 μmol L?1 (3.5–1403.4 ng mL?1) and 0.01–2.0 μmol L?1 (2.0–401.2 ng mL?1), the limit of detection were 3.0 nmol L?1 (1.1 ng mL?1) and 2.0 nmol L?1 (0.4 ng mL?1), respectively. The present method was subsequently applied to the determination of ST in tomato sauces and Hg2+ in environmental waters, the recoveries of ST and Hg2+ in spiked samples are 95.5–107.8% and 91.4–110.8 %, respectively. 相似文献
13.
Fumi Shozui 《Polymer Degradation and Stability》2010,95(8):1340-217
New lactate (LA)-based terpolymers, P[LA-co-3-hydroxybutyrate (3HB)-co-3-hydroxyhexananoate (3HHx)]s, were produced in recombinant Escherichia coli LS5218 harboring three genes encoding LA-polymerizing enzyme (LPE), propionyl-coenzyme A (CoA) transferase (PCT) and (R)-specific enoyl-CoA hydratase (PhaJ4). When the recombinant LS5218 was grown on glucose with the feeding of butyrate, 3HB-CoA and 3HHx-CoA were supplied, probably via reverse reactions of the β-oxidation pathway and PhaJ4. LPE copolymerized the two monomers 3HB-CoA and 3HHx-CoA with LA-CoA, which was generated by PCT, to yield the terpolymers. Gas chromatography analysis revealed that the terpolymers consisted of 2.7-34 mol% LA, 38-81 mol% 3HB and 17-33 mol% 3HHx units, which can be varied depending on the butyrate concentration fed in the medium. In addition, 1H-13C COSY NMR analysis provided evidence for a linkage between LA and 3HHx units in the polymer. 相似文献
14.
在用电智能化管理和配电自动化中,利用电力线载波通信是一种最有效、最经济、最简便的数据传输方式。在实验和应用电力线载波集成芯片ST7538的基础上,首先对该芯片的功能、特点及工作原理进行了较全面的介绍;然后根据其特点、工作模式及数据传输方式等方面设计了一种新型、高效的电力线载波通信接口电路,该电力线载波通信接口电路主要由发送滤波器、耦合变压器、接收滤波器、保护电路四部分组成。最后通过反复实验、长期测试与现场应用,证明了电力线载波集成芯片ST7538具有性能优良、功能强大、使用方便等特点,其接口电路既能高效率地传输载波信号,又能完全地隔离50~60Hz的工频信号,具有进一步推广应用的价值。 相似文献
15.
介绍了高清IPTV机顶盒开发平台的搭建设计过程,包括主机开发环境的建立,STLinux及其文件系统的移植,Bootloader的配置和烧写,NFS开发模式的配置。在软件的配合下,实现基于Xbox多媒体中心(XBMC)框架的机顶盒系统。 相似文献
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17.
介绍了利用ST公司的8位微控制器(MCU)ST6210来控制充电器的硬件电路和软件流程。该方法通过把拐点法和[-ΔV]的检测、温度监控和计时器的切断等三种补充的充电终止方法相结合,可以达到安全充电和增加电池使用寿命的目的。 相似文献
18.
以升华剂2,4,6-三异丙基-1,3,5-三氧六环为溶质,无水乙醇为溶剂,采用溶液挥发法培养了2,4,6-三异丙基-1,3,5-三氧六环的单晶.利用X-射线单晶衍射法测定其单晶结构,并通过紫外光谱、热重和X-射线粉末衍射等手段对其进行了表征.结果表明,标题化合物属于正交晶系,Pnma空间群,晶胞参数:a=0.827 7(3)nm,b=1.024 4(3)nm,c=1.683 1(5)nm,α=β=γ=90°,V=1.427 1(8)nm~3,Z=42,Mr=216.81,Dc=1.007g/cm~3,μ=0.070mm~(-1),F(000)=480.0,T=293(2)K,最终偏差因子(对I2σ(I)的衍射点)R1=0.083 7,wR2=0.264 8.化合物分子中的六元环呈椅式构型,分子间存在的弱氢键作用使得其沿c轴方向形成了一维无限链状结构.通过测量其饱和蒸气压随温度变化,按Clausius-ClaPeyron方程计算得出其升华焓为15.82kJ/mol,再结合热重TGA-DTA曲线、DSC曲线和焓变分析,可以判定升华剂在80℃之前没有发生分解产生新的物质. 相似文献
19.
Yong-Hyun Kim Ki-Hyun Kim Jan E. Szulejko Min-Suk Bae Richard J.C. Brown 《Analytica chimica acta》2014
For the quantitative analysis of ‘compounds lacking authentic standards or surrogates’ (CLASS) in environmental media, we previously introduced an effective carbon number (ECN) approach to develop an empirical equation for the prediction of their response factor (RF). In this research, a series of laboratory experiments were carried out to benchmark the reliability of an ECN approach for sorbent tube/thermal desorption/gas chromatography (GC)/mass spectrometry (MS) applications. First, the ECN values were determined using external calibration data from 25 reference volatile organic compounds (VOCs) using two MS dectectors (quadrupole (Q) and time-of-flight (TOF)). Then, a certified standard mixture of 54 VOCs was analyzed by each system as a simulated unknown sample. The analytical bias, assessed in terms of percentage difference (PD) between the certified and ECN-predicted mass values, averaged 19.2 ± 16.1% (TOF-MS) and 28.2 ± 27.6% (Q-MS). The bias using a more simplified carbon number (CN)-based prediction increased considerably, yielding 53.4 ± 53.3% (TOF-MS) and 61.7 ± 81.3% (Q-MS). However, the bias obtained using the ECN-based prediction decreased significantly to yield average PD values of 9.84 ± 7.28% (TOF-MS) and 16.8 ± 8.35% (Q-MS), if the comparison was limited to 26 (out of 54) VOCs with CN ≥ 4 (i.e., 25 aromatics and hexachlorobutadiene). 相似文献
20.
嵌入式实时操作系统μC/OS-Ⅱ串口通信的设计与实现 总被引:1,自引:0,他引:1
为解决实时操作系统μC/OS-Ⅱ串口通信设计中信号量、消息邮箱使用方法的问题,提出了一种以STM32V评估板为硬件平台和μC/OS-Ⅱ的串口通信程序设计方案.该方案采用Codex-M3架构的ARM处理器STM32F103VB作为主控制芯片,ST3232作为串口通信电平转换器.软件设计部分描述了信号量、消息邮箱的应用场合... 相似文献