具备高效析氢催化效率的三维多孔氮化钒八面体催化剂

随着中国经济和社会的快速发展,能源需求和环境污染问题也日益渐长. 发展和开发高效清洁的新能源燃料可以有效地缓解能源危机和环境污染. 如今,研发高效、环境友好和低成本的催化剂仍是析氢反应的研究重点. 在此项研究中,作者首先通过煅烧处理方式制备了一种三维多孔的氮化钒八面体结构型的催化剂. 该催化剂具备高效的析氢效率,包括较低的过电位94.0 mV（在-10 mA·cm^-2时）,塔菲尔斜率为54.6 mV·dec^-1,以及在酸性条件80小时展现出的优良稳定性,该氮化钒的析氢催化效率优于许多报道过的氮化物,其优良的催化效率可以归因于它独一无二的自身性质和大量的活性位点.     

非线性系统失稳的前兆与地震预报——响应比理论及其应用

本文在分析了不同的非线性系统的失稳过程后得出:其失稳前兆为响应率不断增高或响应比不断增高,而且系统临近失稳时加载与卸载的响应是不同的.将这一理论用于地震预报.利用起潮力引起的地壳中应力的周期性变化,作为加、卸载的手段.如能分别测量出固体潮加载周期与卸周期引起的响应(如地形变、重力、地震活动性等)的比值,这一参量必然包含地震孕育的特征信息. 用1970—1988年间发生在中国大陆的9个M≥7的大地震的资料,将该区域内中小地震所释放的能量的平方根(Benioff称之为释放应变)作为固体潮加卸载的响应,9个地震中的7个,在震前其响应比明显增高.     

THE PRECURSOR OF INSTABILITY FOR NONLINEAR SYSTEMS AND ITS APPLICATION TO EARTHQUAKE PREDICTION

By analysing the instability process of various nonlinear systems, we conclude that their instability precursors are the continual heightening of the response rate or response ratio.Applying this theory to earthquake prediction, we adopt the periodical change of the stress in crust caused by the tide-generating force as the loading and unloading. If we can measure the ratio of the response (such as crust deformation, gravity and seismicity) during the loading period to that during the unloading period, this parameter must contain some characteristic information about the seismogenic process.With nine earthquakes (M≥7) data that occurred in Chinese mainland during 1970-1988, we take the sum of square root o?energy of small earthquakes, which is called the released strain by Benioff, as the response to the tidal loading and unloading. We find that the response ratios of seven earthquakes increase obviously before the main earthquakes.