电子探针在新疆拜城碱性花岗岩烧绿石研究中的应用

本文利用电子探针对新疆拜城碱性花岗岩中的烧绿石进行了研究.通过背散射图像分析可知拜城碱性花岗岩中烧绿石多为不规则粒状,颗粒直径在30 ～ 150 μm,与氟碳铈镧矿、萤石、磁铁矿等伴生;利用元素面扫描得出碱性花岗岩烧绿石中Nb、Ta、U、La、Ce、F等稀有、稀土元素的分布情况;并对碱性花岗岩中烧绿石进行了定量分析,表...     

晋北蓝晶石、十字石和红柱石的宝石矿物学特征及形成条件

晋北的十字石、蓝晶石和红柱石从研究区北部的尖山至南部的何家兰表现出一定的规律性。通过矿物成分和矿物共生组合分析,利用地质温度计并结合前人的实验数据对研究区变质地层中的蓝晶石、十字石和红柱石的形成温度和压力进行估算,结合研究区的构造特征阐明其成因。结果表明,该区西川河断裂以北地区地层中的十字石和蓝晶石形成于中压条件下[p=(5.5～7)×108Pa],变质温度为520～550℃;西川河断裂以南地区地层中的红柱石形成于较高的温度(t=570～600℃)和较低的压力(低于3×108Pa)。十字石、蓝晶石和红柱石的形成与该区西川河断裂区域变质作用有关。西川河断裂控制了南北地区的变质条件,进而控制了十字石、蓝晶石和红柱石的形成条件和空间分布。     

A study on sampling methods for chloride profiles: simulations using data from EPMA

Investigating marine concrete by determining the chloride profile is a common way for making a prediction of the remaining service life of a structure. The most common methods of sampling concrete for this purpose is dust sampling by dry drilling or sampling cores which are analyzed by profile grinding in a laboratory. Now, a similar study has been performed, by simulating different sampling techniques in data from EPMA. The results from the simulations of the concrete specimen analyzed with the EPMA, confirm the results from earlier performed dry drilling tests in laboratory and shows the same extensive variations when chloride content is presented as % by weight of concrete instead of as % by weight of calcium oxide. Comparing the results from the earlier performed sampling by dry drilling with the results from the EPMA simulations, it is seen that the dry drilling probably is afflicted with a systematic error by “movement” of dust into the sampling holes when drilling. This study also shows effects of large aggregates in small bores even though the cement content is referred to. However, no signs of “shadowing” by the aggregates was detected when the simulations where performed. Even “horizontal” drilling was simulated in order to be able to detect this possible effect of the aggregates on the chloride ingress into the concrete.     

Sol-gel法制备Al2O3复合膜的EPMA研究

研究采用Sol—gel法成功地制备了一种新型的A12O3—SiO2-TiO2-ZrO2复合陶瓷膜，其膜面平整，无宏观缺陷。利用电子探针微区分析(EPMA)重点研究了膜的表面和膜与基体界面的化学成分及微观结构。并分析了修饰物添加剂对膜的形貌和性能的影响。结果表明TiO2、SiO2、ZrO2掺杂对A12O3膜起到了良好的修饰作用。     

Self-healing protective films prepared on zinc electrodes by treatment in a cerium(III) nitrate solution and modification with sodium phosphate and calcium or magnesium nitrate

Self-healing protective films were prepared on a zinc electrode by treatment in a Ce(NO₃)₃ solution and modification with Na₃PO₄ and Ca(NO₃)₂ or Mg(NO₃)₂. The protective and self-healing abilities of the films were examined by polarization measurements and observation of pit formation after the electrode was scratched with a knife-edge and immersed in aerated 0.5 M NaCl for many hours. The protective efficiency of the film modified with Ca(NO₃)₂ was higher than that of the film without Ca(NO₃)₂ but the self-healing ability of the former film was not sufficiently high during the prolonged immersion. Mechanisms of the protective and self-healing activities were discussed using X-ray photoelectron spectroscopy and electron-probe microanalysis.     

硫酸盐还原菌对海泥中Q235钢腐蚀界面的影响

从钢基体与腐蚀产物界面的角度,深入研究了海泥中硫酸盐还原菌对Q235钢的腐蚀行为的影响.结果表明,最初的腐蚀产物为铁的(水合)氧化物,在硫酸盐还原菌代谢活动的影响下,腐蚀产物逐渐向贫硫,以及富硫的铁硫化物转化.后者的晶体缺陷较多且结构疏松,不能阻挡Fe2 的扩散和侵蚀性离子的渗入,导致腐蚀加速.微生物的代谢产物以及腐蚀产物的转变为点蚀的形成和扩展提供了条件,其点蚀的位置一般发生在晶界和珠光体区,并沿晶界或珠光体扩展.     

汽车轴承部件异常开裂的电子探针分析

使用电子探针对某汽车轴承部件在成型过程中出现的开裂失效进行了解析,解释了出现失效裂纹的主要原因是部件中间位置出现元素硫的偏析聚集使得中间位置不易形成与其他位置一致的铁素体＋珠光体组织,而能够细化晶粒的元素铝的负偏析导致中间位置形成粗大的铁素体组织,另外,粗大的非金属复合夹杂物的存在进一步割裂了基体性能的连续性,恶化了中间位置的综合性能。结果表明,电子探针高灵敏度的特征,能够直观地表征微量元素铝和硫的偏析分布。同时,可借助电子探针背散射检测器高灵敏度的特点,直接进行渗层的观察和评价。     

电子探针背散射电子图像在碳酸盐岩微区分析中的意义

碳酸盐岩成分虽然简单,然而结构却非常复杂,微区分析显得尤为重要。因显微镜等常规仪器性能有限,难以用来进一步提高微区分析的精度。电子探针的使用则大大提高了微区分析研究的精度与深度。使用该仪器能对研究对象进行几千倍甚至十万倍的显微结构观察,可以发现高清晰的微米级、纳米级的微观地质现象;同时可以定位分析相应微观结构的成分,即将化学成分与显微结构一一对应起来,真正实现原住、可靠的精细微区分析。本文重点研究了电子探针中的一种最重要的图像——背散射电子图像,在碳酸盐岩微区分析中所起的作用。除了其在上述显微结构与微区分析精确定位方面的意义之外,它在岩石矿物识别方面的意义也不容小觑。     

Influence of the addition of vanadium on the hydrogenation properties of the compounds TiFe0.9Vx and TiFe0.8Mn0.1Vx (x = 0, 0.05 and 0.1)

TiFe_0.9 and TiFe_0.8Mn_0.1 hydrides have suitable equilibrium pressures at ambient conditions and are potential candidates for hydrogen storage applications. In this work, we study the influence of the addition of small amounts of vanadium on the hydrogenation properties of TiFe_0.9V_x and TiFe_0.8Mn_0.1V_x (x = 0, 0.05 and 0.1) alloys. The excess of Ti from TiFe in these materials results in the precipitation of Ti and Ti₂Fe-type phases. In the analysis of the chemical composition, vanadium was observed in small amount in all phases for each sample which contains vanadium. Vanadium tends to substitute Fe sites, which results in a decrease of the plateau pressures. The addition of vanadium as TiFe_0.8Mn_0.1V_x (x = 0.05 and 0.1) alloys has beneficial effects on the equilibrium plateaus of the hydrides: the plateaus become flatter and a significant reduction in the pressure hysteresis is observed.     

Direct adhesion of natural rubber to nickel/sulfur plating during curing

- Direct adhesion between natural rubber and nickel/sulfur plating during curing was investigated. A nickel/sulfur plating was obtained by the addition of sodium thiosulfate Na₂S₂O₃ ·a 5H₂O to a nickel chloride plating bath. The sulfur content of the plating depends on the concentration of sodium thiosulfate, Na₂S₂O₃ · 5H₂O, the bath temperature and the plating current density. The nickel/sulfur plating is deposited in an amorphous form and the sulfur is distributed uniformly. When the nickel/sulfur plating and natural rubber are cured in a hot press, direct adhesion is formed. The sulfur content around 30% gives the best adhesion and a thinner plating is preferable. The amorphous nickel/sulfur plating is transformed to a crystalline phase [mixture of α-nickel and nickel sulfide (Ni₃S₂)] during curing. It is suspected that less heat stress is generated in the case of a thinner plating which causes better adhesion to rubber.