A core-shell copper oxides-cobalt oxides heterostructure nanowire arrays for nitrate reduction to ammonia with high yield rate

Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still face relatively low NH3yield rate and poor stability. We present here a core-shell heterostructure comprising cobalt oxide anchored on copper oxide nanowire arrays(CuO NWAs@Co_(3)O_(4)) for efficient NRA. The CuO NWAs@Co_(3)O_(4)demonstrates significantly enhanced NRA performance in alkaline media in comparison with plain CuO NWAs and Co_(3)O_(4)flocs. Especially, at-0.23 V vs. RHE, NH_(3) yield rate of the CuO NWAs@Co_(3)O_(4)reaches 1.915 mmol h^(-1)cm^(-2),much higher than those of CuO NWAs(1.472 mmol h^(-1)cm^(-2)), Co_(3)O_(4)flocs(1.222 mmol h^(-1)cm^(-2)) and recent reported Cu-based catalysts.It is proposed that the synergetic effects of the heterostructure combing atom hydrogen adsorption and nitrate reduction lead to the enhanced NRA performance.

High?Index?Faceted Ni_3S_2 Branch Arrays as Bifunctional Electrocatalysts for Efficient Water Splitting

For efficient electrolysis of water for hydrogen generation or other valueadded chemicals, it is highly relevant to develop low-temperature synthesis of low-cost and high-e ciency metal sulfide electrocatalysts on a large scale. Herein, we construct a new core–branch array and binder-free electrode by growing Ni_3S_2 nanoflake branches on an atomic-layer-deposited(ALD) TiO_2 skeleton. Through induced growth on the ALD-TiO_2 backbone, cross-linked Ni_3S_2 nanoflake branches with exposed { 210} highindex facets are uniformly anchored to the preformed TiO_2 core forming an integrated electrocatalyst. Such a core–branch array structure possesses large active surface area, uniform porous structure, and rich active sites of the exposed { 210 } high-index facet in the Ni_3S_2 nanoflake. Accordingly, the TiO_2@Ni_3S_2 core/branch arrays exhibit remarkable electrocatalytic activities in an alkaline medium, with lower overpotentials for both oxygen evolution reaction(220 mV at 10 mA cm^(-2)) and hydrogen evolution reaction(112 m V at 10 mA cm^(-2)), which are better than those of other Ni_3S_2 counterparts. Stable overall water splitting based on this bifunctional electrolyzer is also demonstrated.

A Hybrid Electrode of Co_3O_4@PPy Core/Shell Nanosheet Arrays for High-Performance Supercapacitors

Herein, combining solverthermal route and electrodeposition, we grew unique hybrid nanosheet arrays consisting of Co_3O_4 nanosheet as a core, PPy as a shell. Benefiting from the PPy as conducting polymer improving an electron transport rate as well as synergistic effects from such a core/shell structure, a hybrid electrode made of the Co_3O_4@PPy core/shell nanosheet arrays exhibits a large areal capacitance of 2.11 F cm-2at the current density of 2 m A cm^(-2), a *4-fold enhancement compared with the pristine Co_3O_4electrode; furthermore, this hybrid electrode also displays good rate capability(*65 % retention of the initial capacitance from 2 to 20 m A cm^(-2)) and superior cycling performance(*85.5 % capacitance retention after 5000 cycles). In addition, the equivalent series resistance value of the Co_3O_4@PPy hybrid electrode(0.238 X) is significantly lower than that of the pristine Co_3O_4electrode(0.319 X). These results imply that the Co_3O_4@PPy hybrid composites have a potential for fabricating next-generation energy storage and conversion devices.

Directional construction of Cu2S branch arrays for advanced oxygen evolution reaction

Metal sulphide electrocatalyst is considered as one of the most promising low-cost candidates for oxygen evolution reaction(OER).In this work,we report a novel free-standing Cu2S branch array via a facile TiO2-induced electrodeposition-sulfurization method.Interestingly,cross-linked Cu2S nanoflake branch is strongly anchored on the TiO2 backbone forming high-quality Cu2S/TiO2/Cu2S core-branch arrays.The branch formation mechanism is also proposed.As compared to the pure Cu2S nanowire arrays,the asprepared Cu2S/TiO2/Cu2S core-branch arrays show much better alkaline OER performance with lower overpotential(284 mV at 10 mA cm^-2)and smaller Tafel slope(72 dec-1)as well as enhanced longterm durability mainly due to larger exposed area and more active electrocatalytic sites.Our work provides a new way for construction of advanced metal sulphide electrocatalysts for electrochemical energy conversion.

Magnetic field induced phase branches of the superconducting transition in two-dimensional square π-loop arrays

Based on the results of explicit forms of free energy density for each possible arrangement of magnetization fluxes in large-scale two-dimensional （2D） square π-loop arrays given by Li et al [2007 Chin. Phys. 16 1450], the field-cooled superconducting phase transition is further investigated by analysing the free energy of the arrays with a simplified symmetrical model. Our analytical result is exactly the same as that obtained in Li＇s paper by means of numerical calculations. It is shown that the phase transition splits into two branches with either ferromagnetic or anti-ferromagnetic flux ordering, which depends periodically on the strength of external magnetic flux φe through each loop and monotonically on the screen parameter β of the loops in the arrays. In principle, the diagram of the phase branches is similar to that of its one-dimensional counterpart. The influence of thermal fluctuation on the flux ordering during the transition from normal to superconducting states of the π-loop arrays is also discussed.

高校附属医院党支部参与临床业务科室决策机制研究

附属医院作为高校与医疗事业的关键,临床科室是其发展核心。新时代下,加强党支部参与临床科室决策的机制,是贯彻党的领导、强化医院管理的必然要求。高校附属医院党支部具有的“双重”属性,通过在临床业务科室设立党支部参与决策的“核心组”,搭建高效决策平台,配套议事规则和监管措施构建机制实现其功能作用,深入剖析管理挑战并提出改进对策,以创建党支部决策新途径、新机制,推动党建与业务深度融合。

超声雷达综合法检测钢筋混凝土构件内部缺陷研究

设计了一块内置不同人工缺陷的钢筋混凝土试块,结合探地雷达扫描成像法和相控阵超声成像法对试块内置缺陷进行检测,并通过钻芯取样法对结果进行验证。结果表明,探地雷达成像法和相控阵超声成像法均能准确反映混凝土内部缺陷,探地雷达具有更高的灵敏度,相控阵超声成像法成像更直观。

基于FPGA IPCore的1024点傅里叶变换的实现

本文主要研究傅利叶变换(后简称FFT)算法实现的问题。在传统的利用DSP实现FFT的方法中,主控器的数据吞吐量小,存储器资源不够,速度慢,难以达到FFT实时性的要求。为解决这些问题,本文提出了一种直接调用Altera公司的FFT知识产权核(IPCore)来实现1024点FFT的方法。通过对FFT核模块、状态机控制模块、存储器以及其他外部控制电路的研究设计,实现了10位的1024点FFT运算。利用现场可编程门阵列(后简称FPGA)丰富的内部资源和FFT IPCore的灵活性,简化了FFT算法实现的设计流程。仿真结果表明,这种方法快捷简便,而且能满足不同复杂程度FFT算法的需求。

Assembling Co_9S_8 nanoflakes on Co_3O_4 nanowires as advanced core/shell electrocatalysts for oxygen evolution reaction

Rational design of advanced cost-effective electrocatalysts is vital for the development of water electrolysis. Herein, we report a novel binder-free efficient CoS@CoOcore/shell electrocatalysts for oxygen evolution reaction（OER） via a combined hydrothermal-sulfurization method. The sulfurized net-like CoSnanoflakes are strongly anchored on the CoOnanowire core forming self-supported binder-free core/shell electrocatalysts. Positive advantages including larger active surface area of CoSnanoflakes,and reinforced structural stability are achieved in the CoS@CoOcore/shell arrays. The OER performances of the CoS@CoOcore/shell arrays are thoroughly tested and enhanced electrocatalytic performance with lower over-potential(260 m V at 20 m A cm) and smaller Tafel slopes（56 mV dec-1） as well as long-term durability are demonstrated in alkaline medium. Our proposed core/shell smart design may provide a new way to construct other advanced binder-free electrocatalysts for applications in electrochemical catalysis.

新时代大学生学习型党支部践行社会主义核心价值观的路径探究

当代中国精神最准确的体现是社会主义核心价值观,这代表全体人民的价值追求。高校大学生党支部是最基层的学生党组织,承担着坚定理想信念,提高大学生党员素质,帮助大学生健康成长,密切联系师生的关键作用。该文从社会主义核心价值观引领高校学生党支部建设的意义和难点出发,然后从线下、线上层面提出强化体制建设,加强队伍培训,完善学习制度,强化活动牵引力,利用“学习强国”APP创新管理和运行机制等路径。

站场工艺管道小口径支管角焊缝相控阵超声检测工艺

小口径支管是站场工艺管道重要组成部分,受其管径小、结构复杂等因素的影响,目前的无损检测技术有效性不高,大量小口径支管角焊缝的安全状况不明,是站场工艺管道的安全隐患。采用CIVA仿真软件对典型规格的小口径接管角焊缝模型进行仿真,分析不同工艺参数下焊缝内部声场的特点及变化规律,优化了相控阵无损检测工艺,并在模拟试件上开展5种典型缺陷的试验验证,验证结果表明,提出的相控阵检测工艺可以有效检测出模拟试件中的典型缺陷,缺陷实测尺寸误差在10%以内。

采用振动传感阵列的高压并联电抗器铁心松动故障诊断方法

铁心松动是高压并联电抗器长期振动效应下的主要机械故障之一,利用单点振动信号分析法对其进行缺陷诊断存在测点选择困难、数据不具备典型性等缺点,而利用振动传感阵列可有效避免以上问题。介绍了基于质量‑弹簧模型的并联电抗器铁心振动机理,通过高压并联电抗器振动测试平台,确立了高压并联电抗器油箱振动形态测试方案,得到各个频率分量下高压并联电抗器油箱表面的振动形态,分析了电压和铁心松动对高压并联电抗器油箱表面基频振动形态的影响。借鉴图像形态学中纹理特征的提取方法提出了一种基于振动强度共生矩阵的特征提取算法,以铁心处于紧固状态和不同松动状态下的10 kV并联电抗器模型为算例,验证了所提算法的有效性。

基于FVC-CNN模型的野外车辆声信号分类

针对野外环境下单通道车辆声信号受风噪影响严重、分类性能较低的问题,提出一种基于声阵列4通道同步采集信号的一维卷积神经网络模型(FVC-CNN)。该模型借鉴注意力机制加权平均的思想对Inception网络结构进行改进,作为输入层有针对性地提取4通道声信号多个不同时间尺度的特征,抑制噪声干扰,再根据不同车辆声信号特征分布特点,分别训练3个特征提取网络SWNet、LWNet和TNet来提取相应车辆的特征,最后对提取的特征进行多分支多维度的融合以供分类。在相同数据集上进行验证,实验结果表明,FVC-CNN模型总识别率可达94.22%,相较于传统方法识别率提高14.08%,取得了较好的分类效果。

基于PCIe的高精度低杂散信号源设计

为了在动态压力测试系统中提供1种精度高、便携式与可靠性强的信号源以完成校准测试工作,通过采用现场可编程门阵列(FPGA)芯片作为控制核心,设计了1种高精度、低杂散的信号源。基于直接数字式频率合成器(DDS)基本原理,利用高速串行计算机扩展总线(PCIe)标准发送上位机指令及大量波形数据,通过16位的4通道模数转换芯片DAC8544输出各类型信号。采用Xilinx提供的DDS Compiler知识产权(IP)核与Block Memory Generator知识产权(IP)核实现任意信号及调制信号的输出,以减少设计电路体积。此外,提出引用有限长单位冲激响应(FIR)滤波器插值滤波与相位抖动技术,对输出杂散进行了处理。试验结果表明,信号源频率范围为10 Hz~10 MHz,幅值±5 V可调,无杂散动态范围优于60 dB,频率误差在0.05%以内。该信号源输出信号精度高、杂散低,具有实际的应用价值,也可用于航空发动机、汽轮机等其他动态测试领域。

长条形阵列铁芯磁通门性能研究

为了提高微型磁通门传感器的性能,改进铁芯结构,基于MEMS工艺制作了35组不同结构的长条形阵列铁芯。利用双铁芯线圈结构磁通门对制作的35组长条形阵列铁芯进行了磁通门性能指标的测试,分析了长条形阵列铁芯排列密度以及单条铁芯宽度对磁通门最佳激励电流、线性范围、灵敏度以及噪声的影响规律。研究结果表明,当单条铁芯相邻宽度为35μm以及单条铁芯宽度为60μm时,长条形阵列铁芯的磁通门综合性能指标优于传统薄膜铁芯的磁通门性能。

最佳激励电流磁通门铁芯结构的仿真优化与分析

在分析微型磁通门的功耗主要受最佳激励电流影响的基础上,提出了一种通过减小退磁系数的长条形阵列铁芯减小微型磁通门的最佳激励电流,以达到降低功耗的目的。利用有限元仿真软件Magnet对长条形阵列铁芯进行了结构分析与优化,研究了长条形阵列铁芯尺寸和阵列密度与微型磁通门最佳激励电流的关系,为微型磁通门从改变铁芯拓扑结构方面降低功耗提供了技术思路和数据支持。

基于Solidworks Simulation仿真分析的ZJ118卷烟机双芯加热搓板装置设计

目的 为解决卷烟机在生产中细支卷烟时,因搓板加热不均匀导致的水松纸泡皱、皱纹、翘边等质量问题。方法 基于SOLIDWORKS Simulation仿真分析设计了一种400 W+800 W双芯加热搓板装置,代替原有的1 200 W单芯加热搓板装置,并通过仿真分析2种搓板加热装置在设定温度为200℃时的热量分布情况,然后在实际生产中验证改造方案的应用效果。结果 仿真分析的结果表明,400 W+800 W双芯加热搓板装置的热量极限和加热效率都比1 200 W单芯加热搓板装置高,双芯加热能更加快速地达到设定温度,搓板体上的热量分布更均匀,搓板面上的热量分布也更加稳定,温差较小,能够更好地保证卷烟搓接质量的稳定性。实际应用效果显示,使用双芯加热搓板装置后,再也没有出现水松纸泡皱、皱纹、翘边等质量问题。结论 400 W+800 W双芯加热搓板装置具有加热效率高、热量分布均匀、温差小等优点,能更有效地提高卷烟搓接质量,既大大减少了卷接质量事故出现频次和设备停台维修时间,也降低了卷烟生产消耗。

一种宽带微带单脉冲阵列天线设计

设计了一种工作在C波段的宽带微带单脉冲阵列天线,采用口径耦合馈电和附加寄生贴片方式拓展微带天线带宽,利用三分支定向耦合器结构设计宽带微带和差网络,并与4×4微带阵列天线组成宽带单脉冲阵列天线,设计仿真后加工实物,经过实测,天线工作带宽1.2 GHz。

阵列式位移计的300m级高心墙堆石坝沉降监测方法研究

因传统变形监测仪器存活率低、精度差,难以满足高心墙堆石坝沉降监测需要,提出了基于阵列式位移计的高心墙堆石坝沉降监测方法,并在两河口水电站大坝心墙沉降监测中得到成功应用,沿两河口大坝2760m高程心墙轴线拉通埋设的3套(共计400m长)阵列式位移计,完整揭示了大坝心墙沿轴线的沉降分布及发展规律。监测成果表明阵列式位移计具有精度高、量程大、环境适应性强等特点,能较好解决300m级高堆石坝变形监测面临的“高水压、高土压、大变形”等技术难题,是一种应用前景广阔的高堆石坝沉降监测新技术。

基于Verilog语言的CAN总线错误分析及仿真

CAN总线是一种串行数据通信总线,主要用于车载设备之间的通信。CAN总线是一种无主总线,在通信过程中每个节点均可以作为主机进行发送,作为从机进行接收,各个节点发送数据时采用仲裁机制进行发送,保证了数据发送的有序性,但是同时也容易受到外界干扰而发生错误。列举了CAN总线错误的状态、CAN总线错误的种类以及触发机制,对CAN总线错误基于Verilog代码进行分析,并通过ISIM仿真对CAN总线各种错误的触发机制进行了研究,分析了CAN总线错误产生的原因。