锗γ能谱测量中的符合相加修正

本文介绍了锗γ能谱测量中符合相加修正的原理和方法,给出了修正公式。分别计算了不同几何条件下两个锗探测器对一些放射性核素的符合相加修正因子,估计了符合相加修正因子对活度测量结果的误差贡献。     

HHD型核子秤电离室物理性能检测

HHD型核子秤电离室已成功地使用于HCS型核子秤.对它的各种物理性能指标进行了检测,各项性能指标都达到了设计要求。     

Improved Repeatability of Pulsed Field Magnetometry Measurements Through Peltier Effect Temperature Control of Measurement Coils

Pulsed Field Magnetometers (PFMs) offer a method for high speed full loop characterisation of hard magnetic materials. As there is no dependency on iron to close a circuit, the repeatability of the technique is good. By utilising Peltier effect techniques to control the temperature of the measurement coil systems employed in a Pulsed Field Magnetometer, the level of repeatability of measurements can be significantly improved.     

波长为515nm的氩离子激光器的频率稳定

用声光晶体对氩离子激光作频率调制,获得了碘分子的差拍饱和吸收信号。将得到的斜率极陡的—阶微商形式的饱和吸收信号作为鉴频曲线把氩离子频率激光稳定到~(127)I_2分子的p(13)43—0的a_3超精细分量上。通过与一稳定到相同精细分量的稳频氩离子激光拍频,给出激光频率稳定性优于±6.5×10~(-12),重复性优于±3.4×10~(-11)。     

Characterization of temporal response, spectral responsivity and its spatial uniformity in photoconductive diamond detectors

Three photoconductive diamond detectors with highly oriented diamond (HOD) films fabricated by the same process were characterized with respect to temporal response, spectral responsivity and its spatial uniformity over the wavelength range from 190 to 250 nm. Temporal measurements showed a drift in the baseline, suggesting the presence of deep level carrier traps. The responsivity of specimen No. 2 was more than twice those of the other two specimens, but it showed an unpredictable current fluctuation. It was found that the spatial uniformities of all the specimens were too low for radiometric purposes. A prominent peak, thought to be due to photoemission, was found in the responsivity spatial distribution of specimen No. 3 under a negative applied voltage.     

具有非惯量负载转矩补偿功能的伺服永磁同步电机控制方法

通过电机运动学方程建立以负载惯量、黏性阻尼系数、负载重力力矩和负载初始位置角度为需辨识参数的拟合模型函数式,通过基于该模型函数的非线性回归方法拟合得到这四个参数,从而得到非惯量的负载转矩,使其前馈补偿经典电机PI控制方法中的电流环,实现对时变负载转矩的补偿。仿真结果验证了该方法能使速度响应较快跟踪输入的速度命令,避免较大速度误差的出现。     

Assurance of metrological traceability of water determination results in functional materials and pure substances

The problem of water determination in the creation of pure substances and new functional materials with a low moisture content is considered. The structure, metrological characteristics, and prospects of application of the state primary standard of mass fraction and mass (molar) concentration of water in solid and liquid substances and materials GET 173-2013 are presented. Examples of developing thermogravimetric and chemical analyses are provided.     

基于群论方法的苯分子振动模式研究

苯(C₆H₆)作为大气和室内环境中的主要污染物,具有强烈致癌性,是大气环境主要监测的内容之一。基于群论方法分析建立一种苯分子的泛频跃迁谱线计算方法,利用苯分子简正振动模式与光谱活性,获得30个振动模式的振动频率及其不可约表示。基于D₆点群乘法规则,给出苯分子泛频跃迁的振动模式、光谱活性与谱线位置,为后续精确测量近红外区域苯分子未知谱线跃迁提供了数据与理论支撑。