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Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun zhang Shengtao Gao Xingzhao zhang Dacheng Ma Chuanlei Zhu Jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

三相Vienna整流器中点电位波动的机理分析与抑制

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电力电子技术 2018年第7期52卷 7-9页

作者：党超亮同向前宋卫章常亚飞西安理工大学自动化与信息工程学院陕西西安710048

三相三电平Vienna整流器由于具有功率密度高、开关电压应力小、网侧电流谐波小等优势在数据中心供电系统等交直流混合供电电源中获得广泛应用。直流侧中点电位波动作为Vienna整流器固有问题,直接影响网侧电流质量甚至危害系统的安全可... 详细信息

三相三电平Vienna整流器由于具有功率密度高、开关电压应力小、网侧电流谐波小等优势在数据中心供电系统等交直流混合供电电源中获得广泛应用。直流侧中点电位波动作为Vienna整流器固有问题,直接影响网侧电流质量甚至危害系统的安全可靠运行。以基于平均电流控制的三相三电平Vienna整流器为研究对象,详细分析了直流侧中点电位波动机理,从直流中点电位平衡控制本质出发给出了中点电位控制调节系数的精确取值。通过RT-LAB测试平台进行了全面的实时测试分析,结果表明该控制可有效抑制中点电位波动,有效验证了所提理论分析的正确性。

关键词：整流器中点电位平衡控制

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第1期 174-180页

作者： Fan-Xiao Meng Xing-Yu Wang Ka Lu Ju-song Yang Fu-Min zhang Ai-Jun Ma Bao Du Yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

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Accuracy and Consistency of the Explicit-Invariant Energy Quadratization Approach for the Cahn-Hilliard Equation

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Journal of Mathematical Research with Applications 2025年第1期 84-104页

作者： Jun zhang Fangying song Yu zhang Computational Mathematics Research Center Guizhou University of Finance and Economics School of mathematics and statistics Guizhou University of Finance and Economics School of Mathematics and Stastistics Fuzhou University

It is well known that the explicit-invariant energy quadratization (EIEQ) approach can generate fully decoupled, linear and unconditionally energy-stable numerical schemes, so it is favored by many researchers. However, the undeniable fact is that the numerical method obtained by EIEQ approach preserves the “modified” energy law instead of the original *** is mainly due to the introduction of some auxiliary variables in EIEQ scheme, and the truncation error will make the auxiliary variables deviate from the original definition in the process of numerical calculation. The primary objective of this paper is to address this gap by providing the accuracy and consistency of the EIEQ method in the context of the CahnHilliard equation. We introduce a relaxation technique for auxiliary variables and construct two numerical schemes based on EIEQ. The analysis results show that the newly constructed schemes are not only unconditionally energy stable, linear and fully decoupled, but also can effectively correct the errors introduced by auxiliary variables and follow the original energy ***, several 2D and 3D numerical examples illustrate the accuracy and efficiency of the newly constructed numerical schemes.

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磷酸的钼酸铵分光光度法测定改进研究

精细与专用化学品 2017年第8期25卷 31-33页

作者：程雪莲宋香哲张影河北诚信九天医药化工有限公司河北石家庄051130

对现有磷酸的钼酸铵分光光度法进行改进。本研究选择抗坏血酸作为还原剂、用6mol/L硫酸溶液配制钼酸铵,并对配制浓度进行调整,测得工作曲线的相关系数、检出限、精密度都得到了很大提高。

关键词：磷酸分光光度法抗坏血酸

DDoS Attack Autonomous Detection Model Based on Multi-Strategy Integrate Zebra Optimization Algorithm

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Computers, Materials & Continua 2025年第1期82卷 645-674页

作者： Chunhui Li Xiaoying Wang Qingjie zhang Jiaye Liang Aijing zhang School of Information Engineering Institute of Disaster PreventionLangfang065201China Langfang Key Laboratory of Network Emergency Protection and Network Security Langfang065201China

Previous studies have shown that deep learning is very effective in detecting known ***,when facing unknown attacks,models such as Deep Neural Networks(DNN)combined with Long Short-Term Memory(LSTM),Convolutional Neural Networks(CNN)combined with LSTM,and so on are built by simple stacking,which has the problems of feature loss,low efficiency,and low ***,this paper proposes an autonomous detectionmodel for Distributed Denial of Service attacks,Multi-Scale Convolutional Neural Network-Bidirectional Gated Recurrent Units-Single Headed Attention(MSCNN-BiGRU-SHA),which is based on a Multistrategy Integrated Zebra Optimization Algorithm(MI-ZOA).The model undergoes training and testing with the CICDDoS2019 dataset,and its performance is evaluated on a new GINKS2023 *** hyperparameters for Conv_filter and GRU_unit are optimized using the Multi-strategy Integrated Zebra Optimization Algorithm(MIZOA).The experimental results show that the test accuracy of the MSCNN-BiGRU-SHA model based on the MIZOA proposed in this paper is as high as 0.9971 in the CICDDoS 2019 *** evaluation accuracy of the new dataset GINKS2023 created in this paper is *** to the MSCNN-BiGRU-SHA model based on the Zebra Optimization Algorithm(ZOA),the detection accuracy on the GINKS2023 dataset has improved by 5.81%,precisionhas increasedby 1.35%,the recallhas improvedby 9%,and theF1scorehas increasedby 5.55%.Compared to the MSCNN-BiGRU-SHA models developed using Grid Search,Random Search,and Bayesian Optimization,the MSCNN-BiGRU-SHA model optimized with the MI-ZOA exhibits better performance in terms of accuracy,precision,recall,and F1 score.

关键词： Distributed denial of service attack intrusion detection deep learning zebra optimization algorithm multi-strategy integrated zebra optimization algorithm

Integrated Equipment with Functions of Current Flow Control and Fault Isolation for Multiterminal DC Grids

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Energy Engineering 2025年第1期122卷 85-99页

作者： Shuo zhang Guibin Zou School of Electrical Engineering Shandong UniversityJinan250061China Suzhou Research Institute Shandong UniversitySuzhou215123China

The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable *** the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and ***,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power *** solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent *** addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC *** order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC ***,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.

关键词： Integrated equipment multiterminal direct current grid current flow control fault isolation

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运用粒度分析方法探讨古代砂体的沉积环境

同济大学学报 1979年第2期 35-50页

作者：王慧中项立嵩张国栋

本文用薄片粒度的概率累积曲线分析方法,在与其他相指标相互配合的情况下,试从苏、浙、皖老第三系300多个样品的分析探讨古代河床砂、河口坝砂、天然堤与决口扇砂以及浅滩砂粒度分布的基本特征。并注意到这种粒度分析方法,在一定的条件... 详细信息

本文用薄片粒度的概率累积曲线分析方法,在与其他相指标相互配合的情况下,试从苏、浙、皖老第三系300多个样品的分析探讨古代河床砂、河口坝砂、天然堤与决口扇砂以及浅滩砂粒度分布的基本特征。并注意到这种粒度分析方法,在一定的条件下,也适用于碳酸盐砂的环境解释。

关键词：河床相决口扇薄片天然堤自然堤河谷地貌浅滩河床地形砂体斜层理粉砂岩碎屑岩河口坝粒度分析方法概率累积曲线粒度概率图阜二段异化颗粒沉积环境地质环境

比索洛尔联合螺内酯对老年慢性心力衰竭患者心室重构的影响

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广东医科大学学报 2017年第2期35卷 119-121页

作者：陈允祥陈宋璋黄炯泽广东省普宁市人民医院心血管内科广东普宁515300

目的观察比索洛尔联合螺内酯治疗老年慢性心力衰竭的临床效果。方法 106例老年慢性心力衰竭患者随机分为对照组和观察组。对照组按照慢性心力衰竭常规治疗方案进行干预,观察组在此基础上采用比索洛尔联合螺内酯治疗。对比两组的疗效,观... 详细信息

目的观察比索洛尔联合螺内酯治疗老年慢性心力衰竭的临床效果。方法 106例老年慢性心力衰竭患者随机分为对照组和观察组。对照组按照慢性心力衰竭常规治疗方案进行干预,观察组在此基础上采用比索洛尔联合螺内酯治疗。对比两组的疗效,观察患者治疗前后舒张末期室间隔厚度(IVST)、舒张末期左心室内径(LVEDD)、左心室射血分数(LVEF)以及肿瘤坏死因子(TNF-α)、白细胞介素6(IL-6)、NT-proBNP浓度、6 min步行试验的改变。结果观察组的临床疗效优于对照组(P<0.01)。治疗后,观察组的LVEDV、LVESV水平均低于对照组;CI、SV、LVEF、6 min步行距离则高于对照组;治疗后两组患者的TNF-α、IL-6、血清NT-proBNP均低于治疗前,且以观察组更为显著(P<0.05或0.01)。结论采用比索洛尔联合螺内酯治疗老年慢性心力衰竭能够有效提高患者的临床疗效,改善患者的心室重构和心功能。

关键词：慢性心力衰竭螺内酯比索洛尔临床疗效