离子交换树脂相光度法测定蒙药中微量铁

铁(Ⅱ)与2,2′-联吡啶在pH值5左右的HAc-NaAc缓冲溶液中生成有色络阳离子,与强酸性阳离子交换树脂交换吸附,可进行树脂相分光光度法测定痕量Fe(Ⅱ)。最大吸收波长λmax=522nm,表观摩尔吸光系数k=9.12×104L.mol-1.cm-1,比水相中直接分光光度法测定Fe(Ⅱ)的摩尔吸光系数(k=8.23×103L.mol-1.cm-1)提高11倍多。铁(Ⅱ)的含量在0—1.5mg.L-1范围内符合Beer定律。用此法测定蒙药苏斯-12中的微量铁,相对标准偏差为2.3%,回收率在98.4%—100.3%之间。     

Consecutive induction melting of nickel-based superalloy in electrode induction gas atomization

The crucible-free electrode induction melting gas atomization(EIGA) technology is an advanced technology for preparing ultra-clean nickel-based superalloy powders. One of the key issues for fabricating powders with high quality and yield is the consecutive induction melting of a superalloy electrode. The coupling of a superalloy electrode and coil,frequency, output power, and heat conduction are investigated to improve the controllable electrode induction melting process. Numerical simulation results show that when the coil frequency is 400 kHz, the output power is 100 kW, superalloy liquid flow with a diameter of about 5 mm is not consecutive. When the coil frequency is reduced to 40 kHz, the output power is 120 kW, superalloy liquid flow is consecutive, and its diameter is about 7 mm.     

推荐一种硼肥中硼含量测定方法

硼虽仅占植物干重的十万分之一至万分之一,但它在植物糖类代谢过程中起着重要作用,是农作物不可缺少的微量元素之一.缺硼时,农作物根茎于腐、籽粒干瘪,甚至停止生长或死亡.由于硼肥成份复杂,除去干扰物比较困难,因此,其测定方法往往比较繁琐、费时.本文作者结合实验工作,探索出一种简便、快速的方法,并应用于硼肥中常量硼的测     

Oxidation during the production of FGH4095 superalloy powders by electrode induction-melt inert gas atomization

Super-clean and super-spherical FGH4095 superalloy powder is produced by the ceramic-free electrode inductionmelt inert gas atomization(EIGA) technique.A continuous and steady-state liquid metal flow is achieved at high-frequency(350 k Hz) alternating current and high electric power(100 k W).The superalloy is immersed in a high-frequency induction coil,and the liquid metal falling into a supersonic nozzle is atomized by an Ar gas of high kinetic gas energy.Numerical calculations are performed to optimize the structure parameters for the nozzle tip.The undesired oxidation reaction of alloying elements starts at 1000?C with the reaction originating from the active sites on the powder surfaces,leading to the formation of oxides,Me_xO_y.The role of active sites and kinetic factors associated with the diffusion of oxygen present in the atomization gas streams are also examined.The observed results reveal that the oxidation process occurring at the surface of the produced powders gradually moves toward the core,and that there exists a clear interface between the product layer and the reactant.The present study lays a theoretical foundation for controlling the oxidation of nickel-based superalloy powders from the powder process step.     

硼肥中硼元素分离及回收方法的改进

硼肥中硼元素分离及回收方法的改进彭更生史峰山张贵彬（昌吉师范专科学校化学系新疆昌吉８３１１００）关键词硼分离测定中图分类号Ｏ６１２．３关于样品中硼的分离及测定方法已有较多报道［１～５］。Ｎ．Ｗ．汉森和Ｗ．Ｊ．威廉斯曾推荐了肥料中硼元素分离和测定的标准...