羌塘错尼地区新生代火山岩研究

同位素年代学、岩石学、矿物化学和岩石地球化学特征研究表明,羌塘错尼地区火山岩可以划分为3套岩石组合:1高钾钙碱性火山岩(44Ma～38Ma);2钾玄岩质火山岩;3强碱性火山岩(34Ma～19Ma)。3套火山岩均是大陆碰撞造山后期岩浆作用的产物,始新世以来,随着该区由碰撞、挤压作用发展到出现走滑,应力环境由挤压转变为张性,导致依次喷发高钾钙碱性火山岩、钾玄岩质火山岩和强碱性火山岩。强碱性火山岩的地球化学特征暗示了岩浆源区受到过地幔流体的强烈交代作用。

西藏隆鄂尼—昂达尔错地区布曲组白云岩地球化学特征及成因

西藏隆鄂尼—昂达尔错地区中侏罗统布曲组白云岩，是一个具有含油远景的层系，查明其成因，对于正确评价研究区含油远景具有重要意义。为此，对研究区含油白云岩的流体包裹体和碳、氧同位素进行了分析。研究区白云石环带内流体包裹体的均一温度和盐度较高，均一温度集中在130~170℃，盐度集中于3.5%~4.5%，显示白云石环带形成环境的温度及盐度较高，应为深埋藏到成岩晚期产物。白云岩δ18OPDB均小于零且变化范围较大，并向负值偏移，具有低温白云岩和高温白云岩成因。结合大量野外调查和室内测试分析，认为研究区白云岩成因复杂，至少为3期成因的复合，即早期低温准同生白云岩化，中期高温深埋藏白云岩化，晚期构造白云岩化。

西藏文部一姆错丙尼地区早二叠世拉嘎组——兼述杂砾岩形成环境与成因

通过1∶250000邦多区幅和措麦区幅区域地质调查,对西藏文部—姆错丙尼地区的早二叠世拉嘎组进行了地层古生物及杂砾岩特征的研究,发现赋存于滑塌块体中的生物化石反映的地质时期为早二叠世Sakmarian—Artinskian期,而滑塌块体的“基质”地层时代应稍晚于早二叠世Sakmarian—Artinskian期;沉积特征表明杂砾岩成因具冰海相和水下块体重力流的复合(双重)性质。

西藏当雄错—姆错丙尼地区早二叠世拉嘎组及杂砾岩成因探讨

本文通过1∶25万《邦多区幅》和《措麦区幅》区域地质调查,对西藏当雄错—姆错丙尼地区的早二叠世拉嘎组进行了地层古生物及杂砾岩特征的研究,认为:所采生物化石均赋存于滑塌块体中,反映的地质时期为早二叠世Sakmarian-Artinskian期,而赋含滑塌块体的“基质”地层时代应稍晚于早二叠世Sakmarian-Artinskian期;沉积特征表明杂砾岩成因具冰海相和水下块体重力流的双重(复合)性质。

Effect of electropulsing on dislocation mobility of titanium sheet

To investigate the effect of the electropulsing on dislocation mobility,specimens cut from the cold-rolled titanium sheet were treated by high density electropulsing with the maximum current density of 7.22,7.64,7.96 kA/mm 2 ,pulse period 110μs.The internal friction and elastic modulus were measured by a dynamic mechanical analyzer（DMA）.When strain amplitude lowers a certain critical one,the damping of the electropulsed titanium sheet is lower than that of the cold-rolled one.When the strain amplitude exceeds the critical one,the damping of the electropulsed titanium sheet is extraordinarily higher than that of the cold-rolled or conventional annealed one.Furthermore,it is found that the damping peak of the electropulsed titanium sheet shifts to lower temperature compared with the conventional annealed one.It is demonstrated that the electropulsing treatment can decrease dislocation tangles and enhance dislocation mobility.

你喜欢冒险吗

有的人喜欢在冒险与刺激中生活,有的人喜欢在平稳中度日。不能说两者谁优谁劣,只能说各有其益处。不过,在当代竞争激烈、变幻莫测的旋律中,很多弄潮儿都是通过担风险、涉足新事物而改变了逆境和窘迫的状况,甚至成为商界的大款、大腕。细推敲,各行各业,成功者无不与冒险精神沾点边。

High damping capacities of Mg-Cu based alloys

The dynamic mechanical analyzer(DMA)was applied to investigate the damping properties of Mg-Cu based alloys.The results show that the as-cast hypoeutectic Mg-Cu binary alloys exhibit ultra-high damping capacities,while the eutectic Mg-Cu alloy exhibits low damping capacity.The strain amplitude dependent damping performance reveals that the dislocation damping mainly dominates in Mg-Cu alloys.Furthermore,the influence of eutectic phase on damping mechanisms of Mg-Cu binary alloys was discussed in detail and the effect of Si addition on the damping of Mg-1%Cu based alloy was also reported.Two damping peaks are observed on the temperature dependent spectrum of Mg-Cu based alloys.One is located at room temperature,which is dislocation related peak;and the other is located at moderate temperature,which is caused by the grain boundary sliding.

Influence of impurities on damping properties of ZK60 magnesium alloy

The influence of impurities on damping capacities of ZK60 magnesium alloys in the as-cast,as-extruded and T4-treated states was investigated by dynamically mechanical analyzer at room temperature.Granato and Lucke dislocation pinning model was employed to explain damping properties of the alloys.It is found that reducing impurity content can decrease the amount of second-phase particles,increase grain size and improve damping capacity of the as-cast alloy slightly.The as-extruded alloy with lower impurity content is found to possess obviously higher damping capacity in the relatively high strain region than that with higher impurity concentration,which appears to originate mainly from different dislocation characteristics.The variation tendency of damping property with change of impurity content after solution-treatment is also similar to that in the as-extruded and as-cast states. Meanwhile,the purification of the alloy results in an evident improvement in tensile yield strength in the as-extruded state.