PIC16F877具有同步串行口部件SSP(Synchronous Serial Port)用来与其它外围串行接口芯片或其它微控制器进行串行接口,这些外围设备可以是串行EEPROM、移位寄存器、LED显示器、A/D转换器或D/A转换器等.SSP有以下两种工作方式:串行外围接...PIC16F877具有同步串行口部件SSP(Synchronous Serial Port)用来与其它外围串行接口芯片或其它微控制器进行串行接口,这些外围设备可以是串行EEPROM、移位寄存器、LED显示器、A/D转换器或D/A转换器等.SSP有以下两种工作方式:串行外围接口(SPI)和芯片间总线(I2C).SPI的移位寄存接口技术能通过接到任意数量的外部寄存器接口,使单片机上获得任意数量的额外I/O引脚.本文在简介74HC165和74HC595的结构功能的基础上,介绍了利用PIC16F877单片机的SPI外围模块实现输入/输出扩展的接口电路和软件编程方法,扩展的74HC595可以直接驱动LED显示,而不需要其他的器件.展开更多
Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration proc...Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration processes on water structure detected by spectral variations in NIR region. Samples of ultrapure water （MilliQ-Millipore, Vimodrone, Milan, Italy） before and after iterated filtrations were analyzed. NIR spectra were collected in transmission mode in the whole NIR range, by using NIRFIex N500 spectrometer at constant temperature （40 ± 1 ℃）. NIR data were processed using Unscrambler software v. 9.2 in evaluating qualitative differences between filtered and not filtered samples. The information related to possible solvent physical stresses were highlighted in the range 6500-7500 cm^-1. The shifts observed were ascribable to a different distribution of the number of water molecules involved in hydrogen bonds in filtered and not filtered water samples, at constant temperature. NIR spectroscopy, commonly used to study relationship between spectral changes and hydrogen bonds in water at increasing temperature values, was applied to evaluate effects of filtration processes on water structure. The obtained results are in agreement with literature data and allowed the improvement of the knowledge about pure water characteristics when some mechanical perturbations are applied.展开更多
文摘PIC16F877具有同步串行口部件SSP(Synchronous Serial Port)用来与其它外围串行接口芯片或其它微控制器进行串行接口,这些外围设备可以是串行EEPROM、移位寄存器、LED显示器、A/D转换器或D/A转换器等.SSP有以下两种工作方式:串行外围接口(SPI)和芯片间总线(I2C).SPI的移位寄存接口技术能通过接到任意数量的外部寄存器接口,使单片机上获得任意数量的额外I/O引脚.本文在简介74HC165和74HC595的结构功能的基础上,介绍了利用PIC16F877单片机的SPI外围模块实现输入/输出扩展的接口电路和软件编程方法,扩展的74HC595可以直接驱动LED显示,而不需要其他的器件.
文摘Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration processes on water structure detected by spectral variations in NIR region. Samples of ultrapure water （MilliQ-Millipore, Vimodrone, Milan, Italy） before and after iterated filtrations were analyzed. NIR spectra were collected in transmission mode in the whole NIR range, by using NIRFIex N500 spectrometer at constant temperature （40 ± 1 ℃）. NIR data were processed using Unscrambler software v. 9.2 in evaluating qualitative differences between filtered and not filtered samples. The information related to possible solvent physical stresses were highlighted in the range 6500-7500 cm^-1. The shifts observed were ascribable to a different distribution of the number of water molecules involved in hydrogen bonds in filtered and not filtered water samples, at constant temperature. NIR spectroscopy, commonly used to study relationship between spectral changes and hydrogen bonds in water at increasing temperature values, was applied to evaluate effects of filtration processes on water structure. The obtained results are in agreement with literature data and allowed the improvement of the knowledge about pure water characteristics when some mechanical perturbations are applied.
