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CeO_(2)C_(2)Nanoparticles with Oxygen-Enriched Vacancies In-site Self-embedded in Fe,N Co-doped Carbon Nanofibers as Efficient Oxygen Reduction Catalyst for Zn-Air Battery

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Chinese Journal of Chemistry 2022年第23期40卷 2763-2772页

作者： Mingxin Zhang Hui Peng Kanjun Sun Xuan Xie Xiaofei Lei Sitong Liu Guofu Ma Ziqiang Lei Key Laboratory of Eco-functional Polymer Materials of the Ministry of education Key Laboratory of Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhouGansu 730070China College of Chemistry and Chemical Engineering Lanzhou City UniversityLanzhouGansu 730070China

Rational design of robust non-noble electrocatalysts with numerous oxygen vacancies and highly reactive activity for oxygen reduction reaction(ORR)towards Zn-air batteries is extremely paramount yet ***,a novel CeO_(2)C_(2)nanoparticles self-embedded in Fe,N co-doped carbon nanofibers(CeO_(2)C_(2)@Fe-N-C)heterostructure catalyst has been prepared by the in-site dual template assisted electrospinning technique and subsequent high temperature pyrolysis *** to the CeO_(2)C_(2)with oxygen-enriched vacancies and versatile Fe-N-C with rich reactive species and high conductivity,CeO_(2)C_(2)@Fe-N-C catalyst exhibits outstanding catalytic performance in the ORR process,and shows excellent methanol tolerance and cycle *** addition,CeO_(2)C_(2)@Fe-N-C delivers a nearly four-electron transfer process in the process of oxygen reduction catalysis,providing a fast-electrochemical kinetic rate,which makes it an efficient air cathode for the Zn-air ***,the Zn-air battery fabricated with CeO_(2)C_(2)@Fe-N-C cathode achieves superior performance including large open-circuit voltage(1.5 V)and high specific capacity(780 mAh·g–1 at 10 mA·cm–2)together with superior reversibility and cycling stability,outperforming commercial Pt/C *** present work introduces a new strategy to design and develop highly active non-noble catalysts and highlights the synergy from heterostructure in oxygen electrocatalysis for advanced Zn-air batteries.

关键词： Energy conversion Doping Nanoparticles Carbon nanofibers Zn-air battery

Research on Mixed Logic Dynamic Modeling and Finite Control Set Model Predictive Control of Multi-Inverter Parallel System

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Energy Engineering 2023年第3期120卷 649-664页

作者： Xiaojuan Lu Mengqiao Chen Qingbo Zhang Lanzhou Jiaotong University Lanzhou730070China

Parallel connection of multiple inverters is an important means to solve the expansion,reserve and protection of distributed power generation,such as *** view of the shortcomings of traditional droop control methods such as weak anti-interference ability,low tracking accuracy of inverter output voltage and serious circulation phenomenon,a finite control set model predictive control(FCS-MPC)strategy of microgrid multiinverter parallel system based on Mixed Logical Dynamical(MLD)modeling is ***,the MLD modeling method is introduced logical variables,combining discrete events and continuous events to form an overall differential equation,which makes the modeling more *** a predictive controller is designed based on the model,and constraints are added to the objective function,which can not only solve the real-time changes of the control system by online optimization,but also effectively obtain a higher tracking accuracy of the inverter output voltage and lower total harmonic distortion rate(Total Harmonics Distortion,THD);and suppress the circulating current between the inverters,to obtain a good dynamic ***,the simulation is carried out onMATLAB/Simulink to verify the correctness of the model and the rationality of the proposed *** paper aims to provide guidance for the design and optimal control of multi-inverter parallel systems.

关键词： Multiple inverters in parallel microgrid mixed logic dynamic model finite control set model predictive control circulation

Rail Surface Defect Detection Based on Improved UPerNet and Connected Component Analysis

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Computers, Materials & Continua 2023年第10期77卷 941-962页

作者： Yongzhi Min Jiafeng Li Yaxing Li School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou730070China gansu Provincial Engineering Research Center for Artificial Intelligence and Graphics&Image Lanzhou Jiaotong UniversityLanzhou730070China State Grid gansu Electric Power Baiyin Power Supply CompanyBaiyin730900China

To guarantee the safety of railway operations,the swift detection of rail surface defects becomes *** methods of manual inspection and conventional nondestructive testing prove inefficient,especially when scaling to extensive railway ***,the unpredictable and intricate nature of defect edge shapes further complicates detection *** these challenges,this paper introduces an enhanced Unified Perceptual Parsing for Scene Understanding Network(UPerNet)tailored for rail surface defect ***,the Swin Transformer Tiny version(Swin-T)network,underpinned by the Transformer architecture,is employed for adept feature *** approach capitalizes on the global information present in the image and sidesteps the issue of inductive *** model’s efficiency is further amplified by the windowbased self-attention,which minimizes the model’s parameter *** implement the cross-GPU synchronized batch normalization(SyncBN)for gradient optimization and integrate the Lovász-hinge loss function to leverage pixel dependency *** evaluations underscore the efficacy of our improved UPerNet,with results demonstrating Pixel Accuracy(PA)scores of 91.39%and 93.35%,Intersection over Union(IoU)values of 83.69%and 87.58%,Dice Coefficients of 91.12%and 93.38%,and Precision metrics of 90.85%and 93.41%across two distinct *** increment in detection accuracy was *** further practical applicability,we deploy semantic segmentation of rail surface defects,leveraging connected component processing techniques to distinguish varied defects within the same *** computing the actual defect length and area,our deep learning methodology presents results that offer intuitive insights for railway maintenance professionals.

关键词： Rail surface defects connected component analysis Transformer UPerNet

Direct Kerr-lens mode-locked Tm:LuYO_(3) ceramic laser

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Chinese Physics B 2023年第11期32卷 493-497页

作者：令维军薛婧雯杨金芳王翀杜晓娟王文婷张明霞路飞平李向兵董忠 gansu All Solid-State Laser Engineering Research Center Tianshui 741001China Engineering Research Center of Integrated Circuit Packaging and Testing Ministry of EducationTianshui 741001China School of Electronic Information and Electrical Engineering Tianshui Normal UniversityTianshui 741001China

A direct Kerr-lens mode-locked Tm:LuYO_(3)ceramic laser without the aid of any mode-locked starting element is reported for the first time. A pulse duration as short as 259 fs and a maximum average output power of 326 m W are obtained at a repetition rate of 97.1 MHz. The corresponding optical spectrum centered at 2053 nm exhibits a bandwidth of 19.8 nm,which indicates the presence of nearly Fourier transform-limited pulses. Such a Kerr-lens mode-locked Tm:LuYO_(3)ceramic laser is a promising ultrashort pulse source, with both the excellent laser characteristics of Tm:LuYO3and the high-power 790 nm laser diode pumping scheme.

关键词： all solid-state laser ultrashort pulse Kerr-lens mode-locked Tm:LuYO_(3)ceramic

A Study on the Unsteady Flow Characteristics and Energy Conversion in the Volute of a Pump-as-Turbine Device

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Fluid Dynamics & Materials Processing 2021年第6期17卷 1021-1036页

作者： Senchun Miao Hongbiao Zhang Wanglong Tian Yinqiang Li School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou730050China Jiangsu Shuangda Pump Valve Group Co. Ltd.Jingjiang214537China

To study the unsteady flow and related energy conversion process in the volute of a pump-as-turbine(PAT)device,six different working conditions have been *** numerical calculation,the spatio-temporal variation of static pressure,dynamic pressure,total pressure and turbulent energy dissipation have been determined in each section of the *** is concluded that the reduction of the total power of two adjacent sections of the PAT volute is equal to the sum of the power lost by the fluid while moving from one section to the other and the power output from the two adjacent *** a fixed flow rate,the percentage of static pressure energy at the outlet of the PAT is roughly similar to that of the corresponding volute section,and both show a gradually increasing *** turbulent dissipation rate on each section of the PAT volute displays a similar a spatio-temporal behavior for different flow rates.

关键词： Pump as turbine volute energy conversion unsteady numerical simulation

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光电倍增管计数温漂自适应补偿方法

Journal of Measurement Science and Instrumentation 2024年第2期15卷 244-252页

作者：李岗王耀琦王小鹏兰州交通大学电子与信息工程学院甘肃兰州730070

光电倍增管是微光探测的重要器件,使用光子计数法对光强进行检测可以大幅降低噪声的干扰,但光电倍增管的阴极灵敏度、增益及暗噪声易受环境温度的影响,导致输出脉冲幅值的不稳定,影响系统对微光的检测性能。本文通过使用微控制单元、数... 详细信息

光电倍增管是微光探测的重要器件,使用光子计数法对光强进行检测可以大幅降低噪声的干扰,但光电倍增管的阴极灵敏度、增益及暗噪声易受环境温度的影响,导致输出脉冲幅值的不稳定,影响系统对微光的检测性能。本文通过使用微控制单元、数字模拟转换器等模块对光电倍增管设计了高压增益补偿和阈值校正系统,通过对不同温度下光电倍增管的阴极饱和电流、灵敏度和暗噪声的综合分析,构建温度与高压补偿增量Vh及阈值补偿增量Vt混合函数模型,使用补偿增量混合模型对光电倍增管计数输出进行自适应温漂补偿。对滨松的端窗型光电倍增管CR135进行实验,证明了此系统在较大温度变化下仍具有良好的输出信噪比,在-20℃时计数率平均提升0.19,即使引入了少量暗噪声,仍大幅提升了探测性能。

关键词：光电倍增管自适应温漂补偿补偿增量混合模型阴极灵敏度

来自选定多AP的信道状态信息图像室内定位(英文)

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Journal of Measurement Science and Instrumentation 2024年

作者：龙良王小鹏王江李岗兰州交通大学电子与信息工程学院

为了提高使用信道状态信息（channel state information， CSI）图像的室内定位方法的精度，提出了一种使用来自选定多个接入点（access point， AP）的CSI图像的定位方法。该方法分为离线阶段和在线阶段。在离线阶段，根据接收信号强... 详细信息

为了提高使用信道状态信息（channel state information， CSI）图像的室内定位方法的精度，提出了一种使用来自选定多个接入点（access point， AP）的CSI图像的定位方法。该方法分为离线阶段和在线阶段。在离线阶段，根据接收信号强度指示（received signal strength indication， RSSI）从定位区域的四个AP中选择三个AP。然后，使用商用Intel 5300网卡从三个选定的AP收集CSI数据。通过联合来自不同天线的振幅信息和相邻天线之间的相位差信息，为每个选定的AP构建一个单通道子图像。这些子图像合并为三通道的RGB图像，然后将其输入至卷积神经网络 (convolutional neural network， CNN)进行训练，训练完成后保存CNN 模型。在在线阶段，收集来自目标设备的CSI数据，使用与离线阶段相同的步骤将其转换为图像，并输入至训练好的CNN模型。最后，使用基于模型输出概率值的加权质心算法估计目标设备的真实位置。提出方法在室内环境中使用两个数据集进行了验证，取得了良好的定位精度。

关键词： WiFi室内定位多接入点指纹信道状态信息图像卷积神经网络

Research on the phase characteristics and driving mechanism of Chinese business cycle fluctuation--Empirical analysis based on MS-TVTP model

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China Finance and Economic Review 2016年第2期5卷 93-112页

作者： Zhang Tongbin Gao Tiemei School of Mathematics and Quantitative Economics Center for Econometric Analysis and ForecastingDongbei University of Finance and EconomicsChina School of Mathematics and Quantitative Economics Dongbei University of Finance and EconomicsChina

Based on the Keynesian IS curve and MS-TVTP model,this paper studies the phase operating characteristics and driving mechanism of Chinese business growth cycle fluctuation by specifying output gap series through coincident composite index and estimating expectation variable through state space *** results are that the influences of output gap expectation on business growth cycle are positive and the effects of real interest rate are *** of them exert asymmetric features in different *** estimation results of smoothed probability and transition probability show that the financial and investment composite indexes are the significant driving factors of business growth cycle switch among different *** to promoting economic growth,the monetary policy plays a more effective role in decelerating the growth *** the speed of investment’s influence during the economic downturn phase is rapid,the lag of its effects is lengthened due to the investment cycle and capital *** reform dividend through stabilizing expectation and reducing the fluctuation of business cycle by employing the macro prudent government are important ways to maintain the steady growth of Chinese economy.

关键词： growth cycle output gap driving effect MS-TVTP model

The evolution of the cold chain logistics vehicle routing problem:a bibliometric and visualization revie

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Digital Transportation and Safety

Digital Transportation and Safety 2024年第3期3卷 92-114页

作者： Bo Qi Guangyu Li School of Traffic and Transportation Lanzhou Jiaotong UniversityLanzhou 730070China

This paper uses the bibliometric analysis software CiteSpace to examine the current status and evolution of cold-chain logistics vehicle routing problems(CCVRP).7381 relevant articles published in the Web of Science core collection from 2008 to 2024 were analyzed,an in-depth understanding of the publication trends and category distribution were ***,CiteSpace was used to create a scientific knowledge graph and perform visualization *** analysis includes collaboration among authors,countries,and institutions;co-citation analysis of authors,journals,and references;citation burst detection of keywords;and co-citation cluster analysis of *** on a deep understanding of current research hotspots,an in-depth discussion of existing research was conducted from three perspectives:optimization objectives,distribution scenarios,and solution *** results show that CCVRP involves complex factors such as temperature requirements,time window constraints,and multi-objective *** intricate constraints are causing research to become increasingly interdisciplinary and *** evolution of hot topics shows that the research directions span multiple fields,from algorithm design to logistics *** review helps researchers better understand the history,current status,and future development directions of CCVRP research,and provides valuable references and inspiration for academia and practice.

关键词： Cold chain logistics Vehicle routing Carbon emissions Optimization objective Solution algorithm