用穆斯堡尔方法研究辐照时间对原煤微波—磁脱硫的影响

穆斯堡尔谱分析表明，经磁场再分离后，全部磁黄铁矿携带部分非磁性的黄铁矿，硫酸亚铁，陨硫铁均被除去，适当控制辐照时间，使磁黄铁矿生成量达到最大时可得到最佳脱硫率；过深的辐照将使磁黄铁矿进一步分解为反铁磁性的陨硫铁，反而对磁分离脱硫不利。     

600℃下氦离子辐照316L不锈钢氦泡形成的研究

在聚变堆与快堆中，高能中子通过（ｎα）反应在结构材料中产生大量的氦。氦聚集形成氦泡，引起材料各种性能的下降；特别是高温下氦流到晶界形成氦泡，使材料发生脆性断裂。对材料中氦泡的形核及长大规律的研究是研究材料中氦脆的基本机制及堆辐照环境中材料微观结构变化...     

国产改进型316L不锈钢辐照效应随剂量变化研究

加速器驱动洁净能源系统(ADS)是核能可持续发展的一种创新的技术路线。散裂中子源是ADS的三个主要组成部分之一,产生强度约为10~(18)s~(-1)(以中子数计),驱动临界堆。不锈钢常用作散裂中子源的束窗材料,也用作散裂中子源的靶材料。工作过程中不锈钢受到很强的高能质子和中子的照射,年位移损伤剂量可能达到100～200 dpa(每个原子的位移);不锈钢也是重要的快堆等的结     

500℃下316L不锈钢的α粒子辐照起泡

在５００℃下用１．０ＭｅＶ、１．５ＭｅＶ、１．８ＭｅＶ的α粒子轰击混合堆第一壁候选材料－３１６Ｌ不锈钢（固溶态和２０％冷加工态），材料发生严重起泡，引起起泡的通量阈值随入射粒子能量增加而增加。通过对辐照样品的截面微观分析，发现起泡的孕育发展与入射粒子和自身产生的级联碰撞区的联合作用密切相关。起泡发生的区域在损伤峰值区，接近射程末端。     

NiTi形状记忆合金的发射穆斯堡尔谱研究

用发射穆斯堡尔谱学结合其他研究手段分析了ＮｉＴｉ形状记忆合金经不同温度、等时（３０ｍｉｎ）退火及经７００℃水淬和５００℃时效后的缺陷、析出相等微观结构的变化情况，并对近等比ＮｉＴｉ合金经７００℃水淬和５００℃时效后能具有好的记忆性能的原因给出了解释。     

中子辐照后316不锈钢的形变诱发马氏体相变和位错沟槽

采用透射电镜（TEM）研究了在65—100℃温度范围内剂量达0．78dpa（dpa：每晶格原子中的位错数量）中子辐照后的316不锈钢（316SS）的形变组织。在辐照剂量超过0．1dpa时观察到了形变诱发马氏体转变和位错沟槽。对每个位错沟槽中的分切应力（RSS）进行了估计,发现RSS和沟槽宽度在拉伸方向和滑移面法线的夹角为45。左右时达到最大。此外,沟槽宽度随着RgS的增加而增加,表明在高水平的RSS条件下会出现最广泛的局部沟槽形变。不同的应变量下都可以观察到形变诱发的马氏体相,甚至在室温条件下都可以观察到。这些马氏体主要存在于各晶界的交互处。这就表明非常高的应力可以引起γ→α的马氏体转变,引起转变的原因是肖克利不全位错在（111）fcc滑移面上的传播。     

穆斯堡尔谱仪速度参考信号差误信号的计算机采集

通过计算机的声卡以及辅助电路把穆斯堡尔谱仪的速度参考信号和差误信号在计算机上实时采样分析,从而可以随时监控谱仪的运动情况,确保谱仪的工作质量。     

穆斯堡尔效应应用的一些已有探索

发现穆斯堡尔效应已有二十几年历史。目前,穆斯堡尔效应已发展为在物理学、化学、生物医学、地质学、冶金学和磁学等方面获得广泛应用的穆斯堡尔谱学。穆斯堡尔谱学已是一门非常成熟的谱学技术。本文简要地回顾几种非常规的谱学方面的应用,着重讨论了γ射线激光器和利用同步光源的穆斯堡尔效应实验,分析了它     

Complete phase transformation in zirconia induced by very high electronic excitations

It is now well established that the irradiation of pure zirconia (ZrO₂) with swift heavy ions can lead to a transformation from the monoclinic to the tetragonal phase when the deposited electronic energy loss exceeds an effective threshold ∼12 keV nm⁻¹. Previous swift heavy ion irradiations carried out with electronic energy losses less than ∼30 keV nm⁻¹ evidenced that this phase transition is characterized by two constant features: (i) it is driven by a double ion impact process, and (ii) it is never complete even at extremely high fluences. It is then quite interesting to check whether this phase transformation does not depart from this behaviour at very high electronic energy losses. For this purpose, zirconia was irradiated with 0.6-GeV Pb ions giving rise to an electronic energy loss ∼42 keV nm⁻¹ at the sample surface. Despite this huge value, the experimental data revealed that the phase change is here again still characterized by a double ion impact process. However, contrary to previous cases, it was found that this phase transformation not only occurs very rapidly but achieves full completion at rather low fluences.     

离子辐照钨基上碳薄膜微结构的分析

对钨基材料表面上射频磁控溅射沉积的碳膜进行了氩离子和氮离子的辐照,并作了ＸＲＤ及ＸＰＳ的分析。分析结果表明,不同离子辐照引起碳膜微结构的变化亦不同,。氮离子辐照不仅使碳膜元素与基体元素发生混合,而且导致碳膜发生相变,生成碳－化合物,如α－Ｗ２Ｃ、ＷＣｘ,同时氮离子本身与反应生成氮－钨化合物,如ａ－ＷＮ。     

A model for the normal stress dependence of intergranular cracking of irradiated 316L stainless steel in supercritical water

The intergranular cracking behavior of irradiated 316L stainless steel in supercritical water (SCW) was found to be strongly dependent on the local grain boundary normal stress. Tensile specimens of 7 dpa proton irradiated 316L stainless steel were strained in 400 °C SCW to 2%, 5%, and 10% macroscopic plastic strain. The cracking behavior was characterized according to the distributions of cracked grain boundary plane surface trace inclinations to the tensile axis and the Schmid factors of the grains adjacent to the cracked boundaries. Cracks occurred preferentially along grain boundaries with trace inclinations perpendicular to the tensile axis and adjacent to grains with low Schmid factors. There was also a slight increase in cracking propensity for grain boundaries adjacent to grains with high Schmid factor mismatch. The normal stress dependence of intergranular cracking was confirmed by developing and applying the Schmid-Modified Grain Boundary Stress model which characterizes the normal stress acting on a grain boundary as a function of the inclination of the grain boundary plane to the tensile axis and the flow stress of the grain, as estimated from its Schmid factor. By applying this model, the Schmid factor dependence of intergranular cracking could be predicted from the distributions of cracked grain boundary trace inclinations to the tensile axis.     

甘氨酸辐射效应的谱学研究

用固体高分辨核磁共振~(13)C谱、电子自旋共振谱以及X衍射光谱研究了多晶甘氨酸的γ辐射稳定性。结果表明甘氨酸在0—140kGy辐照剂量范围内是稳定的,而~(13)C共振谱线则随着辐照剂量的增加而线性地增宽。     

质子束轰击下MWCNTs无定形结构的转变

在室温下用70keV质子束多壁碳纳米管(MWCNTs),研究了多壁碳纳米管从石墨结构向无定形结构的转变过程。轰击后,MWCNTs外围的石墨结构变成均匀的无定形结构包覆着内部的石墨结构。增大照射量,这种无定形化的过程继续向MWCNTs内层推进,直至形成一个中空的无定形纳米线结构。质子束轰击引入的MWCNTs的结构转变,是从外层向内层逐步推进的石墨结构向无定形结构的转变过程。本文对这种结构演化的机理进行了讨论。     

Hydrogen assisted failure of precracked specimens of 316L stainless steel

The simultaneous action of cathodic hydrogen charging and slow mechanical loading on precracked samples of 316L stainless steel is examined in order to assess the flaw tolerance of this steel, which has been included in the group of possible structural materials for the first wall of the future fusion reactors. The steel is shown to retain a significant part of its flaw tolerance even in the most severe test conditions, but the loading rate is found to change the damage phenomenology of hydrogen from bifurcated crack extension to multi-cracking and enlargement of the blunted crack tip. This change is explained on the basis of a competition mechanism between hydrogen action and mechanical deformation.     

Strain rate dependence of impact properties of sintered 316L stainless steel

This paper uses a material testing system (MTS) and a compressive split-Hopkinson bar to investigate the impact behaviour of sintered 316L stainless steel at strain rates ranging from 10⁻³ s⁻¹ to 7.5 × 10³ s⁻¹. It is found that the true stress, the rate of work hardening and the strain rate sensitivity vary significantly as the strain rate increases. The flow behaviour of the sintered 316L stainless steel can be accurately predicted using a constitutive law based on Gurson’s yield criterion and the flow rule proposed by Khan, Huang and Liang (KHL). Microstructural observations reveal that the degree of localized grain deformation increases, but the pore density and the grain size decrease, with increasing strain rate. Adiabatic shear bands associated with cracking are developed at strain rates higher than 5.6 × 10³ s⁻¹. The fracture surfaces exhibit ductile dimples. The depth and density of these dimples decrease with increasing strain rate.     

液态锂铅合金中316L不锈钢的静态腐蚀行为

采用挂片法、失重法和金相分析,开展了结构材料316L不锈钢在液态锂铅(LiPb)合金中静态腐蚀行为的研究.研究结果表明:316L不锈钢中的组分元素,在液态LiPb合金中发生了溶解和质量迁移,这是导致材料腐蚀的主要原因,而温度和合金中的氧含量是影响静态腐蚀行为最重要的参数.