Magnetic susceptibility of natural rocks and ores is important in many applications. In a few rock types magnetic susceptibility is independent of the direction in which a weak magnetic field is applied. Such rocks ar...Magnetic susceptibility of natural rocks and ores is important in many applications. In a few rock types magnetic susceptibility is independent of the direction in which a weak magnetic field is applied. Such rocks are magnetically isotropic. In most rock types, however, the magnitude of magnetic susceptibility in a constant weak field depends on the orientation of the magnetic field applied. Such rocks are magnetically anisotropic and such directional variation in magnetic susceptibility with these rocks is termed as anisotropy of magnetic susceptibility (AMS). Although attempts have been made on describing AMS using mathematical models, there is still a need to present a more consistent and united mathematical process for AMS. This paper presents a united AMS model by rationalizing the existing pieces of different AMS models through a consistent approach. A few examples of AMS from some types of natural rocks and ores are also presented to substantiate this united AMS model.展开更多
目前很多模数转换器(ADC)缺乏仿真模型,为了大型模数混合信号系统建模与仿真的需要,提出一种基于VHDL模拟混合信号扩展(VHDL Analog and Mixed-Signal Extensions,VHDL-AMS)的流水线ADC结构式建模方法.以多比特位每级的12位分辨率、10 M...目前很多模数转换器(ADC)缺乏仿真模型,为了大型模数混合信号系统建模与仿真的需要,提出一种基于VHDL模拟混合信号扩展(VHDL Analog and Mixed-Signal Extensions,VHDL-AMS)的流水线ADC结构式建模方法.以多比特位每级的12位分辨率、10 MSPS流水线ADC作为建模对象,根据流水线ADC的结构特征,在考虑非理想因素误差情况下,分别建立采样保持放大和乘法数模转换器的VHDL-AMS子模型,然后通过例化建立顶层流水线ADC的结构模型.通过SystemVision和Simulink联合仿真,得到静态性能参数微分非线性度和积分非线性度均小于1LSB,动态性能参数无杂散动态范围94.941 7dB,总谐波失真-94.941 9dB,信噪比58.754 4dB,验证了所提建模方法合的理与有效.展开更多
文摘Magnetic susceptibility of natural rocks and ores is important in many applications. In a few rock types magnetic susceptibility is independent of the direction in which a weak magnetic field is applied. Such rocks are magnetically isotropic. In most rock types, however, the magnitude of magnetic susceptibility in a constant weak field depends on the orientation of the magnetic field applied. Such rocks are magnetically anisotropic and such directional variation in magnetic susceptibility with these rocks is termed as anisotropy of magnetic susceptibility (AMS). Although attempts have been made on describing AMS using mathematical models, there is still a need to present a more consistent and united mathematical process for AMS. This paper presents a united AMS model by rationalizing the existing pieces of different AMS models through a consistent approach. A few examples of AMS from some types of natural rocks and ores are also presented to substantiate this united AMS model.
文摘目前很多模数转换器(ADC)缺乏仿真模型,为了大型模数混合信号系统建模与仿真的需要,提出一种基于VHDL模拟混合信号扩展(VHDL Analog and Mixed-Signal Extensions,VHDL-AMS)的流水线ADC结构式建模方法.以多比特位每级的12位分辨率、10 MSPS流水线ADC作为建模对象,根据流水线ADC的结构特征,在考虑非理想因素误差情况下,分别建立采样保持放大和乘法数模转换器的VHDL-AMS子模型,然后通过例化建立顶层流水线ADC的结构模型.通过SystemVision和Simulink联合仿真,得到静态性能参数微分非线性度和积分非线性度均小于1LSB,动态性能参数无杂散动态范围94.941 7dB,总谐波失真-94.941 9dB,信噪比58.754 4dB,验证了所提建模方法合的理与有效.
