高纯氦气中杂质标准物质的研制

介绍了重量法研制高纯氦气中微量氢气、氖气、氧气、氩气、氮气、甲烷、一氧化碳和二氧化碳8种杂质标准物质的过程,包括重量法制备技术、稀释气中相关杂质的定量及稳定性考察等。研制的8种微量气体标准物质的种类和摩尔分数参照国标GB/T 4844—2011中对高纯氦气的规定,摩尔分数范围在0. 5～4. 0μmol/mol之间,扩展不确定度为1%～3%(k=2)。通过参加CCQM相关国际关键比对,验证了标准物质量值的准确度。与现有的国家二级标准物质相比,研制的标准物质在种类和不确定度方面都已达到了较高水平。

等离子体发射检测器在检测高纯氦气中微量氖气的应用

采用等离子发射检测器（PED） 和氦离子放电检测器（DID） 对重量法制备的氦气中微量氖气进行了检测,对比了微量氖气在两种检测器上的灵敏度和重复性.结果显示,PED 对氖气的检测灵敏度较高,氖气含量在0.03～0.3μmol/mol 范围与响应值呈良好的线性关系,r^2=1.000,检测限小于1 nmol/mol,测定结果的相对偏差小于2%（n=6）.利用大气压离子质谱仪对检测限测试结果进行了验证.采用等离子发射检测器检测氦气中微量氖气的方法,可以降低微量氖气标准物质的定值不确定度,为研制高准确度微量氖气标准物质奠定基础.

精密设备高纯氦气管道施工技术

本文结合重大科研项目低温工厂内工艺管道的施工,分析了精密设备高纯氦气管道施工的过程特点及质量控制,为今后同类型厂房高纯气体管道施工提供了一定的参考借鉴。

低温下活性炭吸附氦气量实验研究

对活性炭低温下氦气吸附量进行了实验研究,在得到椰壳活性炭氦气吸附量的基础上计算得到椰壳活性炭吸附氦气后的比热,并与常用低温回热器磁性填料的比热进行了对比。实验结果表明:在16-30 K温度区间内,温度越低,压力越大,椰壳活性炭对氦气的吸附量越大。在16-30 K温度区间内,20 K以下温区,椰壳活性炭吸附氦气后的比热计算值已经高于常用的回热器填料比热值。根据实验结果,可以选择活性炭作为低温制冷机回热器的填料。

Oxidation behaviors of wrought nickel-based superalloys in various high temperature environments

Oxidation characteristics of Alloy 617 and Haynes 230 at 900 oC in simulated helium environment,hot steam environment containing H2 as well as in air and pure helium conditions were investigated.Compared to air condition,the oxidation rate of Alloy 617 was not significantly affected in helium and hot steam environments,while Haynes 230 showed lower oxidation rate in helium environment.On the other hand,the oxide morphology and structure of Alloy 617 were strongly affected by the environments,but those of Haynes 230 were less dependent on the environments.For Haynes 230,a Cr2O3 inner layer and a protective MnCr2O4 outer layer were formed in all environments,which contributed to the better oxidation resistance.As the mechanical properties,such as creep and tensile properties,were significantly affected by the oxidation behaviors,surface treatment methods to enhance oxidation resistance of these alloys should be developed.