电感耦合等离子发射光谱法测定植株中的硼

1引言 硼是植物必需的微量元素之一。测定植物中硼的方法有甲亚胺比色法、姜黄素比色法、等离子发射光谱法、原子吸收分光光度法等。由于硼的原子化温度较高，原子吸收分光光度法测硼已很少用。姜黄素比色法灵敏度高，但由于显色条件要求严格。不易操作。目前应用最广泛的是甲亚胺比色法和等离子发射光谱法。后者不仅快速、方便、准确，而且其待测液可同时测定磷、钾、硫、铜、锌、铁、锰等植物必需元素的含量，能在实际应用中发挥着更加重要的作用。本实验借鉴石墨炉原子吸收基体改进剂的原理，在样品干灰化中加入适量的Mg（NO3）2或者CaCl2溶液，可使灰化温度从500℃提高到700℃而硼不挥发损失，用ICP-AES测定硼干扰少，检出限为0．0045mg／L，可满足植物测硼的需要。     

Quantum Discord in Two-Qubit System Constructed from the Yang–Baxter Equation

Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way, we investigate the quantum discord of the two-qubit system constructed from the Yang-Baxter Equation. The density matrix of this system is generated through the unitary Yang-Baxter matrix R. The analytical expression and numerical result of quantum discord and geometric measure of quantum discord are obtained for the Yang-Baxter system. These results show that quantum discord and geometric measure of quantum discord are only connect with the parameter θ, which is the important spectral parameter in Yang Baxter equation.     

氢化物发生-原子荧光光谱法测定肥料中微量砷

研究了氢化物发生-原子荧光光谱法测定肥料中的微量砷,优化了最佳检测条件,对肥料样品采用了不同的前处理方法进行了探讨.检出限为0.028mg/kg,线性范围0-100.0μg/L,回收率为95%-100%.该方法操作简便,灵敏度高,准确度好.该法参加了2003年全国肥料中砷的测定能力验证,取得了令人满意的结果.     

拟线性双曲组的经典解的奇性形成

This paper deals with the asymptotic behavior of the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with weaker decaying initial data, and obtains a blow-up result for C1 solution to Cauchy problem.