在光催化产氢反应中引入助催化剂可促进光生电子快速转移, 是提高光催化活性的有效方法。而目前, 高效助催化剂主要仍然是贵金属, 其高昂的价格极大限制了实际应用。本研究探讨了构筑非贵金属助催化剂CoN与g-C₃N₄ 0D/2D紧密界面对光催化制氢性能的影响。负载非贵金属助催化剂CoN可以有效提高2D g-C₃N₄的光催化制氢活性, 负载量对其活性也有影响。构筑的0D/2D紧密界面有利于光生电子快速传输。两者的共同作用使得10% CoN/2D g-C₃N₄复合物光催化制氢效率达到403.6 μmol·g^-1·h^-1, 是2D g-C₃N₄单体的20倍。在CoN/2D g-C₃N₄复合材料中, 负载CoN作为析氢助催化剂可以显著促进电荷转移过程, 从而大幅提高光催化析氢活性。

Selector devices are indispensable components of large-scale memristor array systems. The thereinto, ovonic threshold switching (OTS) selector is one of the most suitable candidates for selector devices, owing to its high selectivity and scalability. However, OTS selectors suffer from poor endurance and stability which are persistent tricky problems for application. Here, we report on a multilayer OTS selector based on simple GeSe and doped-GeSe. The experimental results show improving selector performed extraordinary endurance up to 10¹⁰ and the fluctuation of threshold voltage is 2.5%. The reason for the improvement may lie in more interface states which strengthen the interaction among individual layers. These developments pave the way towards tuning a new class of OTS materials engineering, ensuring improvement of electrical performance.Selector devices are indispensable components of large-scale memristor array systems. The thereinto, ovonic threshold switching (OTS) selector is one of the most suitable candidates for selector devices, owing to its high selectivity and scalability. However, OTS selectors suffer from poor endurance and stability which are persistent tricky problems for application. Here, we report on a multilayer OTS selector based on simple GeSe and doped-GeSe. The experimental results show improving selector performed extraordinary endurance up to 10¹⁰ and the fluctuation of threshold voltage is 2.5%. The reason for the improvement may lie in more interface states which strengthen the interaction among individual layers. These developments pave the way towards tuning a new class of OTS materials engineering, ensuring improvement of electrical performance.

为降低高超声速飞行器再入过程中，产生的气动热辐射对红外探测窗口性能的影响，从轨迹优化的角度，以再入飞行全程驻点总红外辐射为目标函数，提出了一种基于改进鲸鱼优化算法(Whale Optimization Algorithm，WOA)的高超声速飞行器轨迹优化算法。首先，通过Tent混沌映射和控制因子余弦变化改进WOA，改进算法位置更新时的位置指向性，增强算法全局搜索能力；同时，将再入轨迹优化问题转化为控制量剖面参数优化问题，采用倾侧角一次翻转策略，利用普朗克公式计算驻点红外辐射，并设计目标函数，利用阻力加速度再入走廊处理路径约束，采用罚函数法将终端约束同目标函数相结合；最后，利用改进的WOA对设计的控制量剖面进行参数寻优，获得使目标函数最优的解。仿真实验表明： 文中改进的WOA能够有效完成全程总红外辐射最小的再入轨迹优化任务，全局搜索能力强，且具有较好的鲁棒性。

When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping (5%/mol MgO:LiNbO3) under the condition of total reflection, semi-degenerate four-wave mixing (FWM) is generated. On this basis, a more sophisticated frequency conversion process on the interface of nonlinear crystal has been researched. The generation mechanism of FWM is associated with the fundamental waves reflected on the inner surface of the nonlinear crystal. Analysis of the phase-matching mechanism confirms that the FWM is radiated by the third-order nonlinear polarized waves, which are stimulated by the third-order nonlinear susceptibility coefficient of the nonlinear crystal. Theoretically calculated and experimentally measured corresponding data have been presented in this article. These results are expected to provide new inspiration for further experimental and theoretical research on frequency conversion in nonlinear crystals.