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Series-Type Switched-Inductor Z-Source Inverter

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CES Transactions on Electrical Machines and Systems 2020年第1期4卷 53-60页

作者： Xupeng Fang Yingying Tian xiaokang ding Bolong Ma College of Electrical Engineering and Automation Shandong University of Science and Technology

To solve the disadvantages of the traditional Z-source inverter(ZSI),this paper investigates a series-type switched-inductor Z-source inverter(SSI-ZSI)*** not only preserves the advantages of the traditional ZSI,but also improves the voltage *** the condition of the same voltage gain,the capacitor voltage stress is reduced,the soft start characteristic can be achieved and the inverter can be immune to the damage of the inrush *** circuit structure and operating principle are analyzed in detail;the simulation model and the experimental platform are *** simulation and experimental results verify the rationality and superiority of the circuit topology.

关键词： Switched-inductor ZSI PWM series-type.

Design of bifunctional single-atom catalysts NiSA/ZIF-300 for CO_(2) conversion by ligand regulation strategy

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Nano Research 2024年第5期17卷 3827-3834页

作者： Wengang Fu Yapei Yun Hongting Sheng xiaokang Liu Tao ding Shuxian Hu Tao Yao Binghui Ge Yuanxin Du Didier Astruc Manzhou Zhu Department of Chemistry and Centre for Atomic Engineering of Advanced Materials Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationCollege of Materials Science and EngineeringInstitutes of Physical Science and Information Technology and Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized MaterialsAnhui UniversityHefei 230601China Universitéde Bordeaux ISMUMR CNRS N°5255351 Cours de La Libération33405 Talence CedexFrance National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Department of Physics University of Science and Technology BeijingBeijing 100083China Anhui Tongyuan Environment Energy Saving Co. LtdHefei 230041China

Carbon-supported noble-metal-free single-atom catalysts(SACs)have aroused widespread interest due to their green chemistry aspects and excellent ***,we propose a“ligand regulation strategy”and achieve the successful fabrication of bifunctional SAC/MOF(MOF=metal-organic framework)nanocomposite(abbreviated NiSA/ZIF-300;ZIF=ZIF-8)with exceptional catalytic performance and *** designed NiSA/ZIF-300 has a planar interfacial structure with the Ni atom,involving one S and three N atoms bonded to Ni(Ⅱ),fabricated by controllable pyrolysis of volatile Ni-S *** CO_(2) cycloaddition to styrene epoxide,NiSA/ZIF-300 exhibits ultrahigh activity(turnover number(TON)=1.18×105;turnover frequency(TOF)=9830 molSC·mol_(Ni)^(-1)·h^(-1);SC=styrene carbonate)and durability at 70℃ under 1 atm CO_(2) pressure,which is much superior to Ni complex/ZIF,NiNP/ZIF-300,and most reported *** study offers a simple method of bifunctional SAC/MOF nanocomposite fabrication and usage,and provides guidance for the precise design of additional original SACs with unique catalytic properties.

关键词： single atom catalyst bifunctional CO_(2)conversion cycloaddition

Atomically precise Ru-O-Ru clusters for enhanced water dissociation in alkaline hydrogen evolution

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Nano Research 2024年第8期17卷 6993-7000页

作者： Dong Liu Li Xu Sicheng Li Airong Xu Yuanhua Sun Tong Liu Mengyuan Liu Huijuan Wang xiaokang Liu Tao Yao Tao ding Hefei National Research Center for Physical Sciences at the Microscale School of Nuclear Science and TechnologyKey Laboratory of Precision and Intelligent ChemistryNational Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230029China Experimental Center of Engineering and Materials Science University of Science and Technology of ChinaHefei 230026China

Atomic clusters typically exhibit distinctive electronic structures and physicochemical ***,as the size decreases,their ability to adsorb and dissociate water also diminishes,thereby affecting chemical reactions involving water *** the adsorption and dissociation capabilities of atomic clusters towards water molecules and elucidating the mechanisms underlying their performance enhancement have become important research ***,employing the carrier-anchored strategy,Ru-O-Ru atomic clusters were prepared and displayed excellent activity and durability in the hydrogen evolution ***,the Ru-O-Ru atomic clusters exhibited only 86 mV overpotential at 100 mA·cm−^(2) and superior membrane-electrode-assembly activity than commercial Ru/C *** radiation-based Fourier transform infrared spectroscopic measurements revealed that the modification of oxygen in Ru-O-Ru units promoted the reorientation of water molecules from a H-up orientation to H-down,therefore,enhanced the formation of strong hydrogen-bond network of interfacial water on the surface of Ru-O-Ru clusters,leading to enhanced adsorption and dissociation of water and accelerated Volmer *** findings provide a potential strategy and deep insights for the development of atomic clusters in electrocatalysts.

关键词： hydrogen evolution in-situ Fourier transform infrared(FTIR) Ru catalysts electrocatalysis atomic clusters

Regulating atomic Fe-Rh site distance for efficient oxygen reduction reaction

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Science China Chemistry 2024年第4期67卷 1352-1359页

作者： Tong Liu Yudan Chen Airong Xu xiaokang Liu Dong Liu Sicheng Li Hui Huang Li Xu Shuaiwei Jiang Qiquan Luo Tao ding Tao Yao National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Key Laboratory of Precision and Intelligent Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China

Exploring the atomic interaction mechanisms of dense single-atom catalysts(SACs)is of great significance for their application in oxygen reduction reaction(ORR).However,the intrinsic mechanism of the site-distance effect on the catalytic performance has been largely ***,we demonstrate the site-distance effect of Fe-Rh_(x)@NC catalysts in ORR theoretically and *** charge analysis reveals that the strong interaction between Fe and Rh atoms at a certain atomic distance(dFe-Rh)alters the catalytic electronic structure,facilitating the optimization of catalyst adsorption *** by the theoretical calculations,we designed and synthesized the Fe-Rhx@NC catalysts through a spatial confinement *** characterization results prove that the Fe-Rh_(2)@NC has the optimal d_(Fe-Rh),which improves its intrinsic ORR activity,providing a half wave potential of 0.91 V,higher than that of the commercial Pt/C(0.86 V).This study emphasizes the importance of determining the basic mechanism of the site-distance effect in dissimilar metal atoms catalysts,which is conducive to the design of efficient catalyst systems for practical applications.

关键词： Density functional theory single-atom catalyst in-situ encapsulating site-distance effect oxygen reduction reaction

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当前心理健康教育存在的问题及对策探微

成才之路 2021年第22期 28-29页

作者：丁小康甘肃省成县东街小学甘肃成县742500

开展学生心理健康教育是实施素质教育的需要,是社会发展的需要,是学生全面发展的需要,是消除学生厌学情绪的需要。针对当前心理健康教育存在的问题,教师要积极探索相应的对策。转变思想认识、提升专业水平,创设良好的教育大环境,创建“... 详细信息

开展学生心理健康教育是实施素质教育的需要,是社会发展的需要,是学生全面发展的需要,是消除学生厌学情绪的需要。针对当前心理健康教育存在的问题,教师要积极探索相应的对策。转变思想认识、提升专业水平,创设良好的教育大环境,创建“三位一体”的教育网络,是解决当前心理健康教育问题的有效策略。

关键词：心理健康教育重要性问题对策

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串联型Y源逆变器

电子器件 2021年第4期44卷 782-788页

作者：房绪鹏鲁莹丁晓康王璞山东科技大学山东青岛266590 国家电网菏泽供电公司山东菏泽274000

为了克服传统Y源逆变器(YSI)输入电流不连续、电容电压应力和冲击电流大等问题,提出了一种串联型Y源逆变器的拓扑结构。其拓扑结构是在传统Y源逆变器基础上将输入侧二极管和逆变桥的位置进行调换,电容极性也随之反转。串联型Y源逆变器... 详细信息

为了克服传统Y源逆变器(YSI)输入电流不连续、电容电压应力和冲击电流大等问题,提出了一种串联型Y源逆变器的拓扑结构。其拓扑结构是在传统Y源逆变器基础上将输入侧二极管和逆变桥的位置进行调换,电容极性也随之反转。串联型Y源逆变器不但实现了输入侧电流连续,电容电压应力和启动冲击电流小,还保留了传统Y源逆变器高增益的特点。首先对电路的拓扑结构和工作原理进行了分析,并通过数学公式推导证明了电容电压应力和冲击电流,然后用MATLAB/Simulink软件进行仿真分析,最后搭建实验样机进行了验证,仿真和实验结果均证明了电路拓扑的可靠性和优越性。

关键词：逆变器串联型Y源逆变器电压应力冲击电流仿真实验

Q235-304L电偶对在Na_2S溶液中的电偶腐蚀行为研究

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中国腐蚀与防护学报 2006年第5期26卷 308-314页

作者：李君董超芳李晓刚丁小康北京科技大学材料科学与工程学院北京100083

用电化学法和浸泡法研究了Q235-304L电偶对在3种不同浓度的Na2S溶液中的电偶腐蚀行为,用SEM观察试样的表面形貌.结果表明:在3种溶液中Q235钢的阳极过程均为混合控制,而304L的阴阳极过程均为电化学控制;偶接后Q235钢表面阳极金属的溶解... 详细信息

用电化学法和浸泡法研究了Q235-304L电偶对在3种不同浓度的Na2S溶液中的电偶腐蚀行为,用SEM观察试样的表面形貌.结果表明:在3种溶液中Q235钢的阳极过程均为混合控制,而304L的阴阳极过程均为电化学控制;偶接后Q235钢表面阳极金属的溶解过程与阴极过程同时进行,其阳极溶解电流大于电偶电流值;电偶腐蚀效应随阴阳极面积比的增大而增大;随着S2-浓度的升高,电偶对中Q235钢的腐蚀速率减小,电偶腐蚀效应也随之降低.

关键词：电偶腐蚀 Q235钢 304L不锈钢阴阳极面积比

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基于数值模拟的栓塞修复过程中AE信号分析

东北林业大学学报 2012年第4期40卷 71-74页

作者：郝燕华张祥雪丁小康刘姣北京林业大学北京100083

为探讨木质部栓塞修复过程监测到大量AE信号现象的原因,基于Rayleigh-Plesset方程建立描述栓塞修复过程中空化泡的运动方程,并用数值模拟方法得到空化泡运动方程的解,对AE信号进行动力学分析。结果表明:当木质部液水势升高时,空化泡会... 详细信息

为探讨木质部栓塞修复过程监测到大量AE信号现象的原因,基于Rayleigh-Plesset方程建立描述栓塞修复过程中空化泡的运动方程,并用数值模拟方法得到空化泡运动方程的解,对AE信号进行动力学分析。结果表明:当木质部液水势升高时,空化泡会塌缩为半径较小的气泡。但经过一次塌缩并不会使栓塞修复。在压强升高的情况下,气泡会经多次塌缩直到形成稳定的微小气泡,栓塞才会完全修复。在气泡多次塌缩的过程中,气泡半径减小,但是并不是单调减小而是以减幅振动的方式减小,从而形成振源,成为AE信号的来源之一。

关键词：数值模拟木质部栓塞修复 AE信号

基于二维激光与图像的人工林采育目标检测方法

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林业科学 2015年第7期51卷 129-135页

作者：丁小康闫磊孔建磊刘晋浩北京林业大学工学院北京100083

【目的】对人工林区内的采育目标进行检测和识别,为采育作业操作员提供辅助信息,弥补人眼判断的不足,提高作业效率,降低操作风险。【方法】提出一种基于二维激光和图像的人工林采育目标检测方法,主要内容包括以下几个方面:1)基于二维激... 详细信息

【目的】对人工林区内的采育目标进行检测和识别,为采育作业操作员提供辅助信息,弥补人眼判断的不足,提高作业效率,降低操作风险。【方法】提出一种基于二维激光和图像的人工林采育目标检测方法,主要内容包括以下几个方面:1)基于二维激光测距仪和红外热像仪搭建采育目标信息采集系统,利用上位机对传感器的信息采集进行控制,并对采集到的信号进行预处理,获取目标的激光数据、可见光图像和红外热图像;2)将激光与图像进行标定,得到图像中的目标区域,同时由激光坐标得到目标的位置信息,为目标识别和定位打好基础;3)将可见光图像与红外图像进行融合,融合后的图像信息更丰富并减少由单一传感器所引起的不确定性,起到互补的作用;4)根据采育目标的特点,基于激光与图像信息进行特征提取,包括温度特征、颜色特征和形状特征等,为目标识别提供具体依据;5)在获得采育目标特征的基础上,运用当前流行的机器学习算法——支持向量机(SVM),通过大量样本训练和学习,建立特征参数与采育目标的数学模型;6)在SVM模型的基础上,利用3种不同的优化算法对其参数进行优化,提高识别性能。【结果】将不同算法优化后的模型通过受试者工作特征曲线(ROC曲线)进行对比,结果显示,采用遗传算法优化后的模型对人工林采育目标的识别正确率能够达到96%以上,具有较好的识别效果。【结论】将多传感器融合技术引入到林业智能装备中,取代常用的昂贵的三维激光扫描系统,采用二维激光与图像结合的方式,一方面节省了成本,另一方面,针对二维数据,系统的数据处理速度更快;同时,多传感器之间的互补作用使得对目标的测量和识别更为准确。

关键词：激光图像采育目标识别检测