石墨电极的纯度对直读光谱分析的影响

石墨电极的纯度对光谱分析的影响只是在一些书中提及,表作试验研究和分析,对电极的纯度的检验未作有效论述。文中就此问题提出了作者的见解,拟定了检验电极纯度的方法。     

合肥光源测量束团纵向精细结构的单光子计数系统设计

本文介绍了用单光子计数法测量束团纵向精细结构的原理.介绍了合肥同步辐射光源测量束团纵向精细结构的单光子计数系统的设计.由于单光子计数法具有高时间分辨率(2ps)和大的动态测量范围(10⁵)等优点,所以该系统不仅可以测量束团长度,而且可以精密测量单束团的纯净度.最后,分析了该系统的性能,并讨论了该系统在尾场和纵向阻抗的研究、束团伸长效应的研究以及影响单束团不纯净机理的研究中的应用.     

Generation of Entanglement Between Two Noninteracting Qubits via Interaction with Nonclassical Radiation Field

We study the interaction between a single-mode quantized field and a quantum system composed of two qubits. We suppose that two qubits initially be prepared in the mixed and separable state, and study how entanglement between two qubits arises in the course of evolution according to the Jaynes-Cummings type interaction with nonclassical radiation field. We also investigate the relation between entanglement and purity of qubit subsystem. We show that different photon statistics have different effects on the dynamical behavior of the qubit subsystem. When the qubits are initially prepared in the maximally mixed and separable state, for coherent state field we cannot find entanglement between two qubits; for squeezed state field entanglement between two qubits exists in several short period of time; for even and odd coherent state fields of large photon number, the dynamical behavior of the entanglement between two qubits shows collapse and revival phenomenon. For odd coherent state field of small photon number, the entanglement with both qubits initially prepared in maximally mixed state can be stronger than that with both qubits initially prepared in pure states. For fields of small photon number, the entanglement strongly depends on the states they are initially prepared in. For coherent state field, and odd and even coherent state fields of large photon number, the entanglement only depends on the purity of the initial state of qubit subsystem. We also show that during the evolution the unentangled state may be purer than the entangled state, and the maximum degree of entanglement may not occur at the time when the qubit subsystem is in the purist state.     

铸铁光谱分析标准物质内在质量的控制

研制成功低合金铸铁光谱分析标准物质,发现“精炼铁水、提高铸铁自身形成白口化的能力”是研制高品质铸铁光谱分析标准物质的关键。除了关注标准物质的致密性、均匀性、白口化外,对铁水纯净度也应给予特殊的关注。通过采取特殊的铸造工艺,优化冶炼浇注技术,提高铁水纯净度,降低样品中夹杂物的数量,减少其粒度,从而减少铸铁中生成的石墨晶核数量,有效提高铸铁自身形成白口化的能力,最终保证了铸铁光谱分析标准物质的内在质量。     

铸铁光谱分析标准内在质量的控制

研制成功低合金铸铁光谱分析标准物质,发现“精炼铁水、提高铸铁自身形成白口化的能力”是研制高品质铸铁光谱分析标准物质的关键。除了关注标准物质的致密性、均匀性、白口化外,对铁水纯净度也应给予特殊的关注。通过采取特殊的铸造工艺,优化冶炼浇注技术,提高铁水纯净度,降低样品中夹杂物的数量,减少其粒度,从而减少铸铁中生成的石墨晶核数量,有效提高铸铁自身形成白口化的能力,最终保证了铸针光铸铁光谱分析分析内在质量     

Manufacture of Boron-free Magnesia with High Purity from Residual Brine

A novel method for removing boron with ion exchange resin from residual brines tomanufacture boron-free magnesia is described. The concentration of boron in the target magnesiamanufactured thereby from Qinghai salt lakes is lower than 5 μg/g, and the typical D50 size ofproduct is 10.625 μm.