高通量工程试验堆栅元型随堆辐照装置的研制、试验与应用

高通量工程试验堆(HFETR)内的栅元型辐照装置具有较大的灵活性和适用性。几年来,我们使用这类装置开展了一系列材料考验及同位素生产工作。本文介绍了这类装置的设计思想、应用范围、结构特点和试验结果。可供进一步开展栅元型装置研制工作参考。     

压水堆核电站蒸汽发生器设计中的质量保证

本文就蒸汽发生器设计质量保证中的质量保证大纲制定、设计输入、设计过程、设计接口管理和设计验证等主要问题作了论述.     

海平面上宇宙射线电离量的测定及其影响因素的讨论

用自制的圆柱形钢壁充氩高气压电离室在三个不同海拔高度的湖面上,测量了宇宙射线电离量,进而外推出海平面上宇宙射线电离量值为(2.13±0.13)I。又根据在渤海海域的直接测量数据,与上述值比较,得出在渤海测量时所乘钢制船体的γ放射性影响为0.43I(相当于0.74μR/h)。对于测量中若干影响因素进行了初步分析和讨论,认为周围环境物质(例如钢制船体)中天然放射性核素的γ放射性和常压(1atm.)电离室室壁的α发射是影响海平面上宇宙射线电离量数据一致性的两个主要因素。     

碘在生物样品消解和灰化过程中的丢失研究

用＾１３１Ｉ示踪和中子活化法测定了碘在生物样品酸消解和灰化处理中回收率。结果表明：Ｄ 不同酸消化条件下碘的回收率差别很大。当ＨＮＯ３和ＣＨｌＯ４作消化液、用冷却水回流消解时，生物样品中碘的回收率可达９５％以上。用ＫＯＨ在６５０℃灰化时，回收率可达９０％以上。     

全厂断电事故下非能动核电厂系统响应及敏感性研究

福岛核事故发生以后,全厂断电事故成为了关注的热点。为了研究核电厂在全厂断电事故后的系统响应,文章采用系统分析程序针对非能动核电厂的系统、设备建立系统级模型,并开展计算分析。获得了主回路系统、安全系统关键参数的瞬态响应,得出如下结论：全厂断电事故后,非能动核电厂依靠蒸汽发生器（SteamGenerator,SG）和非能动余热排出系统（PassiveResidualHeat Removal system,PRHR）能够及时带出堆芯衰变热;PRHR启动的早晚影响SG二次侧冷却剂进行堆芯余热的带出,但对反应堆冷却能力的影响并不大;堆芯补水箱（CoreMakeupTanks,CMT）向主回路注入冷却剂的质量和速率对主回路温度、压力、稳压器液位的影响很大,可考虑调节CMT注入管线的阻力,使CMT注入流量在合理的水平,防止稳压器发生满溢。     

Droplet Evaporation on a Hydrophilic Mesh Considering Their Sunken Shapes in Holes

The evolution of droplet shapes on a hydrophilic copper mesh was studied by using high-speed microscopic imaging technology. When a water droplet wets a hydrophilic mesh, the liquid-vapor interface initially adopts a convex shape, named as the “first darkness”. Then, as the water evaporates, the liquid-vapor interface flattens, and then it gradually adopts a concave shape; meanwhile, a “second darkness” forms. Taking the shapes of droplets sunken in holes into consideration, the quantitative liquid-vapor interface area was acquired. The evaporation coefficient becomes lower and more reasonable when considering the area increase due to the pentahedron sunken liquid in the holes. A speculation was employed to understand the observed evaporation behavior and the overprediction of the evaporation coefficient.     

Facile preparation of NaV3O8/polytriphenylamine composites as cathode materials towards high-performance sodium storage

NaV₃O₈/polytriphenylamine composites were synthesized by an in situ oxypolymerization way for the first time. Among them, the NaV₃O₈/20 wt.% polytriphenylamine composite shows better cycling and rate performance. Its discharge capacity retains at 118.9 mAh g⁻¹ after 300 cycles at 120 mA g⁻¹. It also obtains a reversible capacity of 101.7 mAh g⁻¹ at 300 mA g⁻¹ after 100 cycles. These enhanced results arise from the excellent morphology, that is, smaller particles of clear edges and uniform distribution suppress the expansion and deformation of the crystal structure, and avoid large agglomerate particles gathering during the electrochemical reaction. In addition, tight polytriphenylamine (PTPAn) coating also improves the conductivity of NaV₃O₈ cathode and suppresses the dissolution of NaV₃O₈ in electrolyte.     

In Situ Investigation and Numerical Simulation of the Failure Depth of an Inclined Coal Seam Floor: A Case Study

Mine Water and the Environment - The 1131 working face of the Yangcheng coal mine was used for a research demonstration to study the failure characteristics of an inclined coal seam floor. A...     

Effect of Heat Treatment on Microstructure and Mechanical Properties of Alloy Mg – 10% Gd – 3% Y – 0.6% Zr

Metal Science and Heat Treatment - The microstructure, mechanical properties and fracture behavior of magnesium alloy Mg – 10% Gd – 3% Y – 0.6% Zr is studied in cast condition and...