PdY8.5Ru0.19合金膜氚老化效应的TEM研究

PdY8.5Ru0.19合金是用于氢同位素分离的膜材料,但涉氚操作后,衰变3He会滞留在合金膜中并形成氦泡,影响其宏观性能.为了解PdY5.5Ru0.19合金膜贮氚老化后,3He在合金膜中的存在形式及分布状态.利用TEM观察分析了贮氚老化45和290 d的PdY8.5Ru0.19合金膜.实验结果表明:在老化45 d的样品中,观察到分布均匀,直径约1 nm的氦泡,同时存在高密度的位错及位错环.在老化290 d的样品中,氦泡直径略微增加,达1.2～1.4nm,且分布均匀,但位错及位错环密度降低.同时,在合金膜中也观察到因氦泡存在而产生的微裂纹与褶皱,这有可能是导致合金膜贮氚后力学性能下降的原因.     

Ti掺杂对ZrCo贮氚合金中氦行为的影响研究

采用掠入射X射线衍射(GIXRD)、弹性离子反冲(ERD)、氦热解吸(TDS)、扫描电镜(SEM)对直流磁控溅射法制备的含氦Zr-Co、Zr-Ti-Co薄膜进行分析,分别得到样品物相、氦的深度和浓度分布、氦热解吸图谱以及热解吸前后的表面形貌。氦热解吸实验曲线反映出Ti的掺杂有利于抑制ZrCo贮氚合金中氦的迁移、聚集和发展,提升相应捕陷位置中氦的释放温度;氦热解吸后,Zr0.8Ti0.2Co薄膜样品的晶界密度相比ZrCo薄膜样品更低,降低减少了氦泡迁移的通道,延缓高温下氦泡迁移合并的趋势,表明掺杂Ti可提升ZrCo合金的固氦能力,对高温条件下氦的释放具有抑制作用。     

脉冲加热-程序升温法研究金属中氦和氢的释放

在一次改造脉冲-热导氢测定仪的基础上,进行二次改造使其具备程序升温功能,应用两次改造后的不同组合,开展了金属中氦和氢热释放的研究。实验结果表明:金属中氦的热释放符合固溶态气体的释放特征,氦在样品熔点附近快速释放,未见高温分解的化合物峰;金属中氢提取未见缓慢热释放图谱,说明氢在固体中的扩散和迁移相对缓慢,固溶态的氢在样品熔点附近快速释放。两种仪器两次改造组合的分析发现脉冲热导法无法区分氦和氢,氦和氢同时释放构成同一个峰,因此,富氦样品必须应用脉冲红外等其他方法定氢,才能确保氢分析的准确性。由于日常普通样品贫氦,考察了7种普通金属中氦含量,探明其值均小于仪器检测限,不会影响到氢的定量分析结果。     

金属中氦缺陷的第一性原理研究

采用第一性原理方法研究了面心立方fcc、体心立方bcc和六方密堆hcp结构金属中氦缺陷,计算分析了三种晶体结构金属中四面体间隙位置、八面体间隙位置和替代位置氦原子的形成能.并比较了fcc、bcc和hcp结构中不同位置氦点缺陷的稳定性.     

用氩—氦混合气体作等离子气提高辉光放电发射光谱仪检测碳的灵敏度

为了提高钢中碳的检测灵敏度，在辉光放电发射光谱仪中使用了氩－氦混合气体作等离子气。由于碳的发射谱线（需）有相对高的激发能量，被具有较高内能的氦离子和亚稳态的氦原子激发更容易产生激发态的碳（而发射谱线）。在测得的灵敏度检测资校准曲线上，由3方面比较，使用氩－氦混合气体比单使用氩气（效果）更好。     

脉冲热导法测定金属中氦

设计快速接口除氢装置,将RH-404脉冲热导定氢仪转化成定氦仪.应用内置气标腔氦气标定,固体氮钢标验证计算过程.脉冲加热热导检测金属中氦,取得令人满意的结果.     

氖氦生产工艺及设备的改进

简述了氖氦生产线的工艺流程与工艺过程，并对原林德公司的工艺及设备进行部分改进，制定了一套独特的操作方法，能充分发挥低温吸附器、分离器的潜在能力，以提高生产效率。即：采用二次净化、精馏、分离循环法，从而克服了长期以来，提取率低、质量差、单机生产次数多、能耗高、劳动强度大的矛盾。     

铝(Ⅲ)-4,5-二溴苯基荧光酮络合物吸附波的研究

在pH6.6的缓冲溶液中,Al(Ⅲ)-Br-PF体系产生一明晰的阴极化极谱波,其二次导数波的峰电位为-0.88V(vs.SCE),峰电流与铝浓度在5.9×10-9～4.1×10-8mol/L范围内呈线性关系.研究了极谱电流的性质,认为获得的极谱波为络合物吸附波,相应络合物的组成为[Al(Br-PF)],条件稳定常数6.3×107.并建立了测定微量铝的灵敏分析方法,应用于碳酸钠、锌合金和铁矿石样品中铝的测定,结果满意.     

改进操作缩短开工时间提高氖、氦产量与质量

首钢氧气厂针对制氧装置中氖氦流程存在的问题改进了氖氦分离装置，开工用混合气改为用纯氖，装置生产以外的冷循环改为停机保持冷状态，国产钢瓶暂代国外钢瓶充氖然后返装，以及强化氖氦系统操作等。     

氦、氩、氪低压激光诱导等离子体激发的空间解析发射图谱的比较

采用二维成像光谱仪系统,研究了铜(样品)和不同氪、氩或氦气压下激光诱导等离子体气体的发射强度空间分布。发射区的形状和强度完全取决于等离子体气体的种类和气压。这些等离子体气体的发射区基本上集中在样品表面附近,而铜样品的发射区则朝周围的气体扩展。氩或氪气压越高,铜线的发射强度越强;而对于氦等离子体,气压越大,铜线的发射强度越弱。上述效应可以通过氪、氩和氦在碰撞激发剖面图上的差别来解释。     

Vacancy Cluster: Helium Synergy in Void Nucleation

Vacancy clusters produced in displacement cascades may capture helium to give void nucleation. Rate equations are derived for such nucleation. Most of the helium is captured and sequestered early on in most irradiations by a low number density of small voids. This capture may terminate void nucleation early in irradiation, in agreement with many experimental studies.     

Use of Dissolved Helium as an Environmental Water Tracer

This study deals with the development, calibration, and testing of an automated technology for using helium as a water tracer in continuous real-time monitoring. The instrument combines a gas extraction system and a helium mass spectrometer. The technology was tested in laboratory pipe, open-water, and porous- media experiments, and the results were used to test helium breakthrough curves against those for salinity expressed by electrical conductivity. The instrument promptly responds to concentration changes. In general, accurate results were obtained for first arrival times and peaks of solutes, as well as for the dispersive characteristics of the breakthrough curves. The accuracy of the elution curves needs some improvement due to limitations of the helium extraction system. In addition, the developed method is sensitive to the water flow rate and nitrogen pressure used in extracting helium from the solution. These issues can be addressed through calibration. Potential improvements are possible through the use of more precise helium concentration quantification equipment and through enhancement of the extraction method. The success of the methodology makes helium an attractive tracer for use near drinking water sources, in environmentally sensitive areas such as wetlands and fish farms, and near recreational or other areas where a esthetics are a concern.     

Helium pneumoperitoneum for laparoscopic cholecystectomy: ventilatory and blood gas changes

Laparoscopic cholecystectomy with carbon dioxide pneumoperitoneum may result in hypercarbia and acidosis in patients with cardiorespiratory disease. The aim of the present study was to assess helium as an alternative to carbon dioxide for creating the pneumoperitoneum. Ventilation requirements and carbon dioxide levels were assessed at the beginning and end of laparoscopic cholecystectomy using helium (n = 30) and carbon dioxide (n = 30) pneumoperitoneum. Insufflation with helium did not result in an increase in ventilation requirement although, like carbon dioxide pneumoperitoneum, it was associated with a mean rise in peak airway pressure (of 7 cmH2O; P < 0.001). There was also a 3.2-kPa increase in the alveolar-arterial oxygen gradient with helium (P = 0.006). Carbon dioxide pneumoperitoneum was associated with a significant rise in arterial carbon dioxide levels, despite increasing ventilation. Four patients with helium pneumoperitoneum had surgical emphysema for 5 days. Helium may be a suitable alternative to carbon dioxide for creating pneumoperitoneum in patients with severe cardiorespiratory disease. However, because of its low water solubility helium has a lower safety margin than carbon dioxide in the rare event of gas embolism.