高寒区引水渠道抽水融冰原型试验及分析

在我国新疆、西藏等西部高寒地区,抽水融冰是解决该地区引水式电站冬季运行冰害的理想措施。本文在对引水渠道冬季运行冰害形成过程及影响分析的基础上,结合新疆玛纳斯河流域红山嘴水电站应用抽水融冰情况,介绍了高寒区引水渠道冬季运行抽水融冰基本原理,并根据抽水融冰原型试验结果分析了抽水融冰的运行效果,给出了渠道水与井水混合后的温度变化过程以及渠道水温沿程变化规律等,进一步论证了抽水融冰理论的正确性和可行性。     

Erratum to “Designing thermal demultiplexer: Splitting phonons by negative mass and genetic algorithm optimization”

Equations (8) and (9) in the original paper [Chin. Phys. B 30 036301 (2021)] are corrected.     

Designing thermal demultiplexer: Splitting phonons by negative mass and genetic algorithm optimization

We propose the concept of thermal demultiplexer, which can split the heat flux in different frequency ranges intodifferent directions. We demonstrate this device concept in a honeycomb lattice with dangling atoms. From the view ofeffective negative mass, we give a qualitative explanation of how the dangling atoms change the original transport property.We first design a two-mass configuration thermal demultiplexer, and find that the heat flux can flow into different ports incorresponding frequency ranges roughly. Then, to improve the performance, we choose the suitable masses of danglingatoms and optimize the four-mass configuration with genetic algorithm. Finally, we give out the optimal configuration witha remarkable effect. Our study finds a way to selectively split spectrum-resolved heat to different ports as phonon splitter,which would provide a new means to manipulate phonons and heat, and to guide the design of phononic thermal devices inthe future.     

Ir在La_2O_2CO_3(001)表面吸附的理论研究

制氢技术是发展燃料电池的关键技术之一,而目前研究较多且具有良好应用前景的制氢技术是醇类水蒸气重整制氢法制氢.具有高活性、高选择性、高稳定性的催化剂在醇类催化制氢过程中起重大作用.采用密度泛函和周期边界模型对La2O2CO3负载Ir催化剂体系界面作用作了理论研究,计算了Ir在La2O2CO3(001)面上的各个吸附位点的吸附能.计算表明Ir原子在La2O2CO3(001)面上各个吸附位点上均发生化学吸附,其中吸附能最高的吸附位点为桥位平行,其吸附能为-479.863 kJ/mol.进而计算了Ir在Ca掺杂的La2O2CO3(001)面上各位点吸附能,结果表明Ca掺杂后的载体对Ir的吸附能力大大提高,且桥位平行位点依旧为最佳吸附位点,其吸附能达到-676.971 kJ/mol.     

吉首市举办非煤矿山、危险化学品安全生产知识培训班

近日,吉首市非煤矿山（采石场）、危险化学品安全生产知识培训班在市委党校举办,全市非煤矿山（采石场）、危险化学品生产经营单位的主要负责人和安全管理人员90余人参加了培训。此次培训重点突出安全生产法律法规,非煤矿山和危险化学品安全管理法律法规、安全管理基础知识的教育,培训课程还包括重大危险源管理、重大事故防范、应急管理、事故应急救援、职业危害以及事故案例分析与讨论等。     

Synthesis of ZnO films with a special texture and enhanced field emission properties

ZnO films with special textures are fabricated on Mo-coated Al₂O₃ ceramic substrates by the catalyst-free electron beam evaporation method, and the as-deposited films are treated by hydrogen plasma. It is found that the surface morphologies of the films are changed significantly after hydrogen plasma treatment and that the films consist of vertically standing and intersecting nanosheets. A lower turn-on field of 1.2 V/μm and an enhanced current density ～0.11 mA/cm² at 2.47 V/μm are achieved. The low threshold field and the high emission current density are attributed primarily to the unique shape and smaller resistivity of the ZnO nanosheet films.     

基于石墨烯-TiO_2复合材料的蛋白质电化学传感器的研究

采用层层涂布法把石墨烯-二氧化钛(GR-TiO_2)复合材料、血红蛋白(Hb)和Nafion滴涂在固体电极表面制备出相应的蛋白质电化学传感器.为了证明Hb与复合材料混合后其原始构象基本不变,采用光谱技术进行表征.利用循环伏安扫描在Hb修饰电极上出现一对良好对称峰形的准可逆氧化还原峰,表明电活性的Hb发生反应.同时利用此方法求解了电化学参数如电子传递系数和异相电极反应速率常数,考察了该电化学传感器对三氯乙酸的电催化行为.