摘要：Rational design and controllable synthesis of efficient electrocatalysts for water oxidation is of significant importance for the development of promising energy conversion systems, in particular integrated photoelectrochemical water splitting devices. Cobalt oxide(Co3O4) nanostructures with mixed valences(Ⅱ,Ⅲ)have been regarded as promising electrocatalysts for the oxygen evolution reaction(OER). They are able to promote catalytic support of OER but with only modest activity. Here, we demonstrate that the OER performance of cubic Co3O4 electrocatalyst is obviously improved when they are anchored on delaminated two-dimensional(2D) Ti3C2 MXene nanosheets. Upon activation the overpotential of the hybrid catalyst delivers 300 m V at a current density of 10 m A cm(2) in basic solutions, which is remarkably lower than those of Ti3C2 MXene and Co3O4 nanocubes. The strong interfacial electrostatic interactions between two components contribute to the exceptional catalytic performance and stability. The enhanced OER activity and facile synthesis make these Co3O4 nanocubes-decorated ultrathin 2D Ti3C2 MXene nanosheets useful for constructing efficient and stable electrodes for high-performance electrochemical water splitting.

摘要：针对我国硬岩铀矿开采中效率低、损失大以及堆浸铀尾渣、含放射性废石处置难等问题,结合“协同开采”理念,提出了硬岩铀矿无废协同开采模式。该模式通过调整回采工程布置,优化充填与尾废处置工艺流程,采取相应的工程技术措施,使采矿与堆浸、采矿与充填、充填与堆排在时间和空间上实现协同,达到安全高效开采铀矿资源和无废处置铀矿冶尾废的目的。以粤北某铀矿为例,分析了现有上向分层干式充填法和堆浸、尾废处置工艺的特点,开展了堆浸铀尾渣充排试验,改进了采矿方法,设计了采—充—排协同工艺方案,并对其工程应用效果进行了评价。研究表明:灰砂比为1∶10和1∶14、质量浓度为76%的充填体,能够满足该矿机械化上向分层充填法和地表同步固化堆排的要求;采用无废协同开采模式后,采场生产能力和回采率可分别提升至135 t/d和88.86%,含放射性废石达到地表零排放,堆浸铀尾渣通过井下胶结充填和地表固化堆排得到了有效处置,矿山经济效益和环境质量得以明显提升。

摘要：为提高铜管体专机整体的工作效率,对机床自动上下料机械手进行了研究。根据铜管体专机上下料的动作要求,设计了一种单臂双爪式机械手,采用PLC作为主控制器,采用气缸作为主执行元件。文中介绍了机械手系统的总体方案、机械结构以及电气控制方法,给出了PLC的I/O地址表、外部接线图以及编程思路。结果表明:此机械手结构简单,便于调试,可实现自动上下料功能,具有很好的实用价值和经济效益。