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Electrochemical radical-polar crossover:a radical approach to polar chemistry

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science China Chemistry 2024年第2期67卷 450-470页

作者： Zhoumei Tan Haonan Zhang Kun Xu Chengchu Zeng Faculty of Environment and Life Beijing University of TechnologyBeijing100124China

Radical-polar crossover(RPC) reaction bridges the gap between one-and two-electron reactivities,thus providing an ideal solution to overcome the limitations of both radical and polar *** this manifold,organic electrochemistry provides a uniquely facile strategy to access a diverse array of radical intermediates,thus broadening the chemical space of the RPC *** review highlights the synthetic advances in the field of electrochemical RPC reactions since 2020,with an emphasis on the substrate scope,reaction limitation and mechanistic *** related RPC reactions are categorized as netoxidative,net-reductive,or redox neutral transformations.

关键词： electrosynthesis radical-polar crossover radical chemistry polar chemistry alkene functionalization

Real-Time Intelligent Diagnosis of Co-frequency Vibration Faults in Rotating Machinery Based on Lightweight-Convolutional Neural Networks

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 264-282页

作者： Xin Pan Xiancheng Zhang Zhinong Jiang Guangfu Bin beijing Key Laboratory of Health Monitoring and Self-recovery for High-End Mechanical Equipment College of Mechanical and Electrical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Engine Health Monitoring-Control and Networking(Ministry of Education) College of Mechanical and Electrical EngineeringBeijing University of Chemical TechnologyBeijing 100029China College of Mechanical Engineering Hunan University of Science and TechnologyXiangtan 411201China

The co-frequency vibration fault is one of the common faults in the operation of rotating equipment,and realizing the real-time diagnosis of the co-frequency vibration fault is of great significance for monitoring the health state and carrying out vibration suppression of the *** engineering scenarios,co-frequency vibration faults are highlighted by rotational frequency and are difficult to identify,and existing intelligent methods require more hardware conditions and are exclusively ***,Lightweight-convolutional neural networks(LW-CNN)algorithm is proposed in this paper to achieve real-time fault *** critical parameters are discussed and verified by simulated and experimental signals for the sliding window data augmentation *** on LW-CNN and data augmentation,the real-time intelligent diagnosis of co-frequency is ***,a real-time detection method of fault diagnosis algorithm is proposed for data acquisition to fault *** is verified by experiments that the LW-CNN and sliding window methods are used with high accuracy and real-time performance.

关键词： Co-frequency vibration Real-time diagnosis LW-CNN Data augmentation

Effect of antenna helicity on discharge characteristics of helicon plasma under a divergent magnetic field

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Plasma science and Technology 2024年第6期26卷 50-59页

作者：孙萌徐晓芳王陈文尹贤轶陈强张海宝 Laboratory of Plasma Physics and Materials School of Printing and Packaging EngineeringBeijing Institute of Graphic CommunicationBeijing 102600People’s Republic of China

The characteristics of the blue core phenomenon observed in a divergent magnetic field helicon plasma are investigated using two different helical antennas, namely right-handed and lefthanded helical antennas. The mode transition, discharge image, spatial profiles of plasma density and electron temperature are diagnosed using a Langmuir probe, a Nikon D90 camera,an intensified charge-coupled device camera and an optical emission spectrometer, *** results demonstrated that the blue core phenomenon appeared in the upstream region of the discharge tube at a fixed magnetic field under both helical antennas. However, it is more likely to appear in a right-handed helical antenna, in which the plasma density and ionization rate of the helicon plasma are higher. The spatial profiles of the plasma density and electron temperature are also different in both axial and radial directions for these two kinds of helical antenna. The wavelength calculated based on the dispersion relation of the bounded whistler wave is consistent with the order of magnitude of plasma length. It is proved that the helicon plasma is part of the wave mode discharge mechanism.

关键词： helicon plasma non-uniform magnetic field helical antenna blue core discharge mechanism

A novel structure of ultra-high-loading small moleculesencapsulated ZIF-8 colloid particles

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Nano Research 2024年第4期17卷 2929-2940页

作者： Pengfei Duan Yunhe An Xiaoxiao Wei Yanjie Tian Di Guan Xiangwen Liu Lanqun Mao Institute of Analysis and Testing Beijing Academy of Science and Technology(Beijing Center for Physical and Chemical Analysis)Beijing 100089China College of Chemistry Beijing Normal UniversityBeijing 100875China

The safety of nanoparticle-based drug delivery systems(DDSs)for cancer treatment is still a challenge,restricted by the intrinsic cytotoxicity of drug carriers and leakage of loaded ***,we propose a novel nanocarrier’s cytotoxicity avoidance strategy by synthesizing an encapsulation core–shell structure of zeolitic imidazolate framework-8(ZIF-8)-based colloid particles(CPs)with an amorphous ZIF-8 *** encapsulation structure achieves an ultra-high loading rate(LR)of 90%(i.e.,9 mg doxorubicin(DOX)per 1 mg ZIF-8)for DOX and the protection of DOX from ***,to deliver unit-dose drug,this ultra-high LR of 90%significantly reduces the usage of ZIF-8 to 1.2%(2 orders of magnitude)compared to that of DOX@ZIF-8 with a 10%LR,in which cytotoxicity of ZIF-8 could well below the safety limit and then be relatively ***,drug delivery efficacy,scale-up ability,and universality of this encapsulation structure have been further *** findings suggest the great potential of this ZIF-8-based encapsulation core–shell structure in the field of drug delivery.

关键词： metal-organic frameworks zeolitic imidazolate framework-8(ZIF-8) drug delivery nanoparticles nanostructures

Almost periodic solutions of memristive multidirectional associative memory neural networks with mixed time delays

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International Journal of Biomathematics 2024年第2期17卷 113-138页

作者： Yan Zhang Yuanhua Qiao Lijuan Duan Faculty of science Beijing University of Technology Beijing 100124P.R.China Faculty of Information Technology Beijing University of Technology Beijing 100124P.R.China

Traditional biological neural networks cannot simulate the real situation of the abrupt synaptic connections between neurons while modeling associative memory of human *** this paper,the memristive multidirectional associative memory neural networks(MAMNNs)with mixed time-varying delays are investigated in the sense of Filippov ***,three steps are given to prove the existence of the almost periodic *** new lemmas are proposed to prove the boundness of the solution and the asymptotical almost periodicity of the solution by constructing Lyapunov ***,the uniqueness and global exponential stability of the almost periodic solution of memristive MAMNNs are investigated by a new Lyapunov *** sufficient conditions guaranteeing the properties of almost periodic solution are derived based on the relevant definitions,Halanay inequality and Lyapunov *** investigation is an extension of the research on the periodic solution and almost periodic solution of bidirectional associative memory neural ***,numerical examples with simulations are presented to show the validity of the main results.

关键词： Almost periodic solutions memristive multidirectional associative memory neural networks mixed time-varying delays global exponential stability

LONP1 ameliorates liver injury and improves gluconeogenesis dysfunction in acute-on-chronic liver failure

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Chinese Medical Journal 2024年第2期137卷 190-199页

作者： Muchen Wu Jing Wu Kai Liu Minjie Jiang Fang Xie Xuehong Yin Jushan Wu Qinghua Meng Department of Liver Disease Beijing You-An HospitalCapital Medical UniversityBeijing 100069China beijing Institute of Hepatology Beijing You-An HospitalCapital Medical UniversityBeijing 100069China Department of General Surgery Beijing You-An HospitalCapital Medical UniversityBeijing 100069China

Background:Acute-on-chronic liver failure(ACLF)is a severe liver disease with complex *** hypoglycemia is common in patients with ACLF and often predicts a worse *** evidence suggests that glucose metabolic disturbance,especially gluconeogenesis dysfunction,plays a critical role in the disease progression of *** protease-1(LONP1)is a novel mediator of energy and glucose ***,whether gluconeogenesis is a potential mechanism through which LONP1 modulates ACLF remains ***:In this study,we collected liver tissues from ACLF patients,established an ACLF mouse model with carbon tetrachloride(CCl 4),lipopolysaccharide(LPS),and D-galactose(D-gal),and constructed an in vitro hypoxia and hyperammonemia-triggered hepatocyte injury ***1 overexpression and knockdown adenovirus were used to assess the protective effect of LONP1 on liver injury and gluconeogenesis *** histopathology,biochemical index,mitochondrial morphology,cell viability and apoptosis,and the expression and activity of key gluconeogenic enzymes were detected to explore the underlying protective mechanisms of LONP1 in ***:We found that LONP1 and the expressions of gluconeogenic enzymes were downregulated in clinical ACLF liver ***,LONP1 overexpression remarkably attenuated liver injury,which was characterized by improved liver histopathological lesions and decreased serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in ACLF ***,mitochondrial morphology was improved upon overexpression of ***,the expression and activity of the key gluconeogenic enzymes were restored by LONP1 ***,the hepatoprotective effect was also observed in the hepatocyte injury model,as evidenced by improved cell viability,reduced cell apoptosis,and improved gluconeogenesis level and activity,while LONP1 knockdown worsened liver injury and gluconeogenesis ***

关键词： Acute-on-chronic liver failure Lon protease-1 Gluconeogenesis disturbance Mitochondrial dysfunction Metabolism

Wave nature of Rosensweig instability

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Chinese Physics B 2024年第3期33卷 471-479页

作者：李柳李德才戚志强王璐张志力 School of Mechanical Electronicand Control EngineeringBeijing Jiaotong UniversityBeijing 100044China beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale Beijing 100044China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

The explicit analytical solution of Rosensweig instability spikes'shapes obtained by Navier-Stokes(NS)equation in diverse magnetic field H vertical to the flat free surface of ferrofluids are systematically studied experimentally and *** carefully analyzing and solving the NS equation in elliptic form,the force balanced surface equations of spikes in Rosensweig instability are expressed as cosine wave in perturbated magnetic field and hyperbolic tangent in large magnetic field,whose results both reveal the wave-like nature of Rosensweig *** results of hyperbolic tangent form are perfectly fitted to the experimental results in this paper,which indicates that the analytical solution is basically *** the forementioned theoretical results,the total energy of the spike distribution pattern is *** analyzing the energy components under different magnetic field intensities H,the hexagon-square transition of Rosensweig instability is systematically discussed and explained in an explicit way.

关键词： ferrofluids Rosensweig instability hexagon-square transition

Principal Model Analysis Based on Bagging PLS and PCA and Its Application in Financial Statement Fraud

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Journal of Systems science and Information 2024年第2期12卷 212-228页

作者： Xiao LIANG Qiwei XIE Chunyan LUO Liang TANG Yi SUN School of Economics and Management Beijing University of TechnologyBeijing 100124China Shanghai Tongtu Semiconductor Technology Co. LtdShanghai 210203China School of Finance Anhui University of Finance&EconomicsBengbu 233000China

Motivated by the Bagging Partial Least Squares(Bagging PLS)and Principal Component Analysis(PCA)algorithms,a novel approach known as Principal Model Analysis(PMA)method is introduced in this *** the proposed PMA algorithm,the PCA and the Bagging PLS are *** this method,multiple PLS models are trained on sub-training sets,derived from the training set using the random sampling with replacement *** regression coefficients of all the sub-PLS models are fused in a joint regression coefficient *** final projection direction is then estimated by performing the PCA on the joint regression coefficient ***,the proposed PMA method is compared with other traditional dimension reduction methods,such as PLS,Bagging PLS,Linear discriminant analysis(LDA)and *** results on six public datasets demonstrate that our proposed method consistently outperforms other approaches in terms of classification performance and exhibits greater ***,it is employed in the application of financial statement fraud *** and other five algorithms are utilized to financial statement fraud which concerned by the academic community,and the results indicate that the classification of PMA surpassed that of the other methods.

关键词： principal model analysis partial least squares principal component analysis dimension reduction ensemble learning financial statement fraud detection

Accurate estimation of Li/Ni mixing degree of lithium nickel oxide cathode materials

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Chinese Physics B 2024年第5期33卷 631-635页

作者：陈鹏浩徐磊禹习谦李泓 Institute of Physics Chinese Academy of SciencesBeijing 100190China Center of Materials science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China beijing Frontier Research Center on Clean Energy Huairou DivisionInstitute of PhysicsChinese Academy of SciencesBeijing 101400China

Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode ***,accurately measuring the Li/Ni mixing degree is difficult due to the preferred orientation of labbased XRD measurements using Bragg–Brentano ***,we find that employing spherical harmonics in Rietveld refinement to eliminate the preferred orientation can significantly decrease the measurement error of the Li/Ni mixing *** Li/Ni mixing ratio obtained from Rietveld refinement with spherical harmonics shows a strong correlation with discharge capacity,which means the electrochemical capacity of lithium nickel oxide and high-nickel ternary cathode can be estimated by the Li/Ni mixing *** findings provide a simple and accurate method to estimate the Li/Ni mixing degree,which is valuable to the structural analysis and screening of the synthesis conditions of lithium nickel oxide and high-nickel ternary cathode materials.

关键词： lithium nickel oxide high-nickel ternary cathode Li/Ni mixing spherical harmonics function discharge capacity