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Chinese Chemical Letters 2009年第1期20卷 25-28页

作者： Jing Li Qiang Liu Rui Guang Xing xiao xia shen Zhen Gang Liu Bo Zhou State Key Laboratory of Applied Organic Chemistry. College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 PR China

A convenient route for the synthesis of 3,4-dihydrocoumarin derivates from salicylaldehyde derivates and 1,3-dicarbonyl compounds under solvent-free microwave irradiation conditions was described. In this way, a range... 详细信息

关键词： 3,4-Dihydrocoumarin Salicylaldehyde Hantzsch ester Microwave irradiation One-pot reaction

Management strategies of neonatal jaundice during the coronavirus disease 2019 outbreak

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World Journal of Pediatrics 2020年第3期16卷 247-250页

作者： xiao-Lu Ma Zheng Chen Jia-Jun Zhu xiao-xia shen Ming-Yuan Wu Li-Ping Shi Li-Zhong Du Jun-Fen Fu Qiang Shu Children's Hospital Zhejiang University School of MedicineHangzhou 310052China National Clinical Research Center for Child Health National Children's Regional Medical CenterHangzhou 310052China Women's Hospital Zhejiang University School of MedicineHangzhou 310003China

The outbreak of coronavirus disease 2019 (COVID-19;formally known as 2019-nCoV) has become a most challenging health *** to rigorous quarantine and control measures taken in China,routine neonatal health surveillance and follow-up have become *** follow-up surveillance,some rapid and progressive newborn diseases,such as bilirubin encephalopathy,may be *** characteristics of onset age of kernicterus suggest that monitoring of bilirubin level at home provides a useful way to alert hospital visits and to prevent the development of extremely ***,we developed an online follow-up program for convenient monitoring of bilirubin level of newborns that is based on our practical *** aim is to make our management strategies of neonatal jaundice tailored to the infection prevention and control during the COVID-19 epidemic.

关键词： New coronavirus pneumonia Hyperbilirubinemia Newborn Follow-up Internet hospital

Achieving structurally stable O3-type layered oxide cathodes through site-specific cation-anion co-substitution for sodium-ion batteries

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Journal of Energy Chemistry 2024年第6期93卷 411-418,I0011页

作者： Yihao shen Chen Cheng xiao xia Lei Wang Xi Zhou Pan Zeng Jianrong Zeng Liang Zhang Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123JiangsuChina Institute for Advanced Study School of Mechanical EngineeringChengdu UniversityChengdu 610106SichuanChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123JiangsuChina

O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical ***,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over *** study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these ***,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,*** as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended *** a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 *** study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.

关键词： Sodium-ion batteries O3-type layered oxides Site-specific co-doping Phase transition

A Probing Model of Secret Key Generation Based on Channel Autocorrelation Function

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China Communications 2024年第6期21卷 163-175页

作者： xia Enjun Hu Binjie shen Qiaoqiao School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China

Secret key generation(SKG)is a promising solution to the problem of wireless communications *** the first step of SKG,channel probing affects it *** there have been some probing schemes,there is a lack of research on the optimization of the probing *** study investigates how to optimize correlated parameters to maximize the SKG rate(SKGR)in the time-division duplex(TDD)***,we build a probing model which includes the effects of transmitting power,the probing period,and the dimension of sample *** on the model,the analytical expression of the SKGR is ***,we formulate an optimization problem for maximizing the SKGR and give an algorithm to solve *** conclude the SKGR monotonically increases as the transmitting power *** mathematical proofs are given in this *** the simulation results,increasing appropriately the probing period and the dimension of the sample vector could increase the SKGR dramatically compared to a yardstick,which indicates the importance of optimizing the parameters related to the channel probing phase.

关键词： channel autocorrelation function channel probing optimization problem physical layer security secret key generation

Systematic bibliometric analysis of research hotspots and trends on the application of premium IOLs in the past 2 decades

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International Journal of Ophthalmology(English edition) 2024年第4期17卷 736-747页

作者： Liang-Pin Li Li-Yun Yuan De-shen Mao xia Hua xiao-Yong Yuan Clinical College of Ophthalmology Tianjin Medical UniversityTianjin 300020China Tianjin Key Laboratory of Ophthalmology and Visual Science Tianjin Eye InstituteTianjin Eye HospitalTianjin 300020China School of Medicine Nankai UniversityTianjin 300071China Anhui Medical University Hefei 230032Anhui ProvinceChina Tianjin Aier Eye Hospital Tianjin UniversityTianjin 300190China

AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 ***:The literature search was performed on the Web of Science and included PIOLs studies published between January 2000 and December *** retrieved literature was collated and analyzed by R-tool’s Bibliometrix package,CitNetExplorer,CiteSpace and other ***:A total of 1801 articles about PIOLs were obtained,most of which were published in Spain and the United *** organization that published the most articles was the University of Valencia in ***ó JL,and Montés-Micó R,from Spain were the most influential authors in this *** Journal of Cataract and Refractive Surgery and Journal of Refractive Surgery were the core journals for this field;the top 10 cited articles mainly focus on postoperative satisfaction with multifocal intraocular lens(IOLs)and postoperative results of toric *** the keyword analysis,we found that trifocal IOLs,astigmatism and extended depth of focus(EDoF)IOLs are the most discussed topics at present,and the importance of astigmatism and the clinical application of the new generation of PIOLs are the emerging research ***:Bibliometric analysis can effectively help to identify multilevel concerns in PIOLs research and the prevailing research trends in the realm of PIOLs encompass the adoption of EDoF IOLs,trifocal IOLs,and their respective Toric models.

关键词： premium intraocular lens bibliometric H-index cataract surgery global trends

Transient Characteristics and Accommodative Current Limiting Strategy for Bidirectional Interlinking Converters in Hybrid AC/DC Microgrids

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1575-1588页

作者： xia shen Zhikang Shuai Wen Huang Chao shen Yang shen Z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616 USA

Bidirectional interlinking converter(BIC)is the core equipment in a hybrid AC/DC microgrid connected between AC and DC ***,the variety of control modes and flexible bidirectional power flow complicate the influence of AC faults on BIC itself and on DC sub-grid,which potentially threaten both converter safety and system *** study first investigates AC fault influence on the BIC and DC bus voltage under different BIC control modes and different pre-fault operation states,by developing a mathematical model and equivalent sequence ***,based on the analysis results,a general accommodative current limiting strategy is proposed for BIC without limitations to specific mode or operation *** amplitude is predicted and constrained according to the critical requirements to protect the BIC and relieving the AC fault influence on the DC bus *** with conventional methods,potential current limit failure and distortions under asymmetric faults can also be ***,experiments verify feasibility of the proposed method.

关键词： Bidirectional interlinking converter current limiting fault characteristic hybrid AC/DC microgrid variation/oscillation of DC bus voltage

A CELL-CENTERED GODUNOV METHOD BASED ON STAGGERED DATA DISTRIBUTION,PART Ⅰ:ONE-DIMENSIONAL CASE

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Journal of Computational Mathematics 2024年第4期42卷 1172-1196页

作者： Jiayin Zhai xiao Li Zhijun shen Institute of Applied Physics and Computational Mathematics LCPP.O.Box 8009-26Beijing 100088China College of Big Data and Internet Shenzhen Technology UniversityShenzhen 518118China Center for Applied Physics and Technology HEDPSPeking UniversityChina

This paper presents a cell-centered Godunov method based on staggered data distribu-tion in Eulerian *** motivation is to reduce the intrinsic entropy dissipation of classical Godunov methods in the calculation of an isentropic or rarefaction *** the same time,the property of accurate shock capturing is also *** analyzing the factors that cause nonphysical entropy in the conventional Godunov methods,we introduce two velocities rather than a single velocity in a cell to reduce kinetic energy dissipation.A series of redistribution strategies are adopted to update subcell quantities in order to improve *** examples validate that the present method can dramatically reduce nonphysical entropy *** subject classification:35Q35,76N15,76M12.

关键词： Godunov method Riemann solver Rarefaction wave Nonphysical entropy increase.

Synthesis of Organofluorine Compounds with Acylsilanes

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Chinese Journal of Chemistry 2024年第8期42卷 887-902页

作者： Youyuan Guo Gang Zhou xiao shen The Institute for Advanced Studies Engineering Research Center of Organosilicon Compounds&MaterialsMinistry of EducationWuhan University299 Bayi RoadWuhanHubei430072 China

Comprehensive Summary,Organofluorine compounds are central in synthetic chemistry,medicinal chemistry and material *** this review,we summarize the investigations on the synthesis of organofluorine compounds with *** the non-fluorinated acylsilanes,the in situ generation of difluoroenoxysilanes from the reactions of the acylsilanes with trifluoromethylation reagents is the major pathway,leading to the facile preparation of variousα,α-*** the fluoroalkylacylsilanes,apart from the in situ generation of difluoroenoxysilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acylsilanes and the selective control of reactivities of the biradicals pave the way for the synthesis of a variety of organofluorine *** general,most of these reactions gave racemic products,and the asymmetric synthesis of organofluorine compounds with acylsilanes is still rare,which would be a future.

关键词： Acylsilanes Organofluorine compounds Brook rearrangement Radical rearrangement β-Fluoride elimination Asymmetric catalysis Photocatalysis Defluoroalkylation

Intelligent Reflecting Surface-Aided Secure and Covert Communications

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China Communications 2024年第9期21卷 1-10页

作者： Zhou xiaobo Jiang Yong xia Tingting xia Guiyang shen Tong School of Information and Artificial Intelligence Anhui Agricultural UniversityAnhui 230036China

This work employs intelligent reflecting surface(IRS)to enhance secure and covert communication *** formulate an optimization problem to jointly design both the reflection beamformer at IRS and transmit power at transmitter Alice in order to optimize the achievable secrecy rate at Bob subject to a covertness *** first develop a Dinkelbach-based algorithm to achieve an upper bound performance and a high-quality *** reducing the overhead and computational complexity of the Dinkelbach-based scheme,we further conceive a low-complexity algorithm in which analytical expression for the IRS reflection beamforming is derived at each *** result shows that the devised low-complexity algorithm is able to achieve similar secrecy rate performance as the Dinkelbach-based *** examination also shows that introducing an IRS into the considered system can significantly improve the secure and covert communication performance relative to the scheme without IRS.

关键词： covert communications intelligent reflecting surface physical layer security reflection beamforming

Harmonic Transfer Function Based Single-input Single-output Impedance Modeling of LCC-HVDC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1327-1332页

作者： Yang Wang Fei xia Ying Wang xianyong xiao College of Electrical Engineering Sichuan UniversityChengdu 610065China

This study presents a harmonic transfer function(HTF)based single-input single-output(SISO)impedance modeling *** method converts an HTF from phase domain to sequence domain and then transforms it into an SISO impedance while preserving the frequency coupling information of different sequences and different *** of this method to a line-commutated converter based high-voltage direct current(LCC-HVDC)system are *** results demonstrate the accuracy of the derived SISO impedance,and a truncation-order selection is *** case study shows that the proposed method facilitates simpler impedance measurements and associated stability analysis.

关键词： Line-commutated converter based high-voltage direct current(LCC-HVDC) harmonic transfer function(HTF) single-input single-output(SISO)impedance frequency coupling