室温高压法将C60转化为钻石

C60分子极为稳定,可承受高达至少20GPa的静压,有人认为在此高压下C60会变成比钻石还硬的固体。本文报道室温下对C60施以压强达20±5GPa的快速非静压,可将其瞬间转化为大量的人工合成钻石结晶的实验情况。

基于激光诱导击穿光谱的室温硫化硅橡胶材料成分研究

室温硫化硅(RTV)橡胶涂料因具有优异的防污闪性能,在电力系统得到了广泛应用。热重分析、X射线能谱分析、傅里叶变换红外光谱分析等材料表征手段经常用以表征RTV涂料的成分和长期运行后的老化状态,但上述方法难以在现场进行。为了实现在线检测RTV材料成分,利用激光诱导击穿光谱(LIBS)对RTV材料进行了元素分析。结果表明,对于同种RTV材料,在相同的激光频率特性与单脉冲激光能量条件下,其烧蚀深度与激光脉冲轰击次数呈线性关系,可通过RTV涂料被轰击次数测量涂料厚度;在材料同一位置用LIBS持续轰击,可以对运行退役的RTV材料进行原位分析,不同轰击次数时的等离子体光谱中Fe、Mg等元素的谱线强度从表层到内部会减小,这证明了RTV材料从表面到内部的成分变化,因此可利用LIBS技术检测RTV材料的成分变化来表征RTV材料的老化状态。高灵敏度、可在线的LIBS技术将成为RTV材料运行状态评估的重要手段。

华北太古宙长英质岩石的地震波速度及其在地壳中的位置

研究了两项内容 :1在室温高压和高温高压条件下 ,华北地区长英质结晶岩的压缩波速度 ;2在常压和石英 α- β相变温度下 ,长英质岩石的加热声发射 .结果表明 :在相同的温压条件下 ,长英质结晶岩的波速明显低于基性岩 ,而与变质相的关系不大 ;含石英岩石的波速曲线具有与其它任何岩石不同的曲线形态 ,显示了 α- β相反应峰 ;在常压下加热岩石至石英相变点时 ,长英质深变质岩和岩浆花岗岩产生声发射 ,另一种交代成因的花岗岩不产生声发射 .其地质意义表明 :结合其它地学资料解释了华北克拉通区的地壳组成 ,阐明了 α石英和β石英的存在空间 ;说明了新生代构造沉降区下地壳岩石中石英的α-β相变以及角闪石和黑云母的脱水熔融是沉降区和隆起区间断裂活动 (张性断裂 )

Investigation on Temperature Separation and Flow Behaviour in Vortex Chamber

In the previous researches, it is known that the swirl flow in circular pipe causes the temperature separation. Recently, it is shown that the temperature separation occurs in a vortex chamber when compressed air are pumped into this device from the periphery. Especially, in a cavity installed in the periphery of the chamber, the highest temperature was observed. Therefore, it is expected that this device can be used as a heat source in the engineering field. In recent researches, the mechanism of temperature separation in vortex chamber has been investigated by some researchers. However, there are few researches for the effect of diameter and volume of vortex chamber, height of central rod and position of cavity on the temperature separation. Further, no detailed physical explanation has been made for the temperature separation phenomena in the vortex chamber. In the present study, the effects of chamber configuration and position of the cavity on temperature separation in the vortex chamber were investigated experimentally.