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Defence Technology（防务技术） 2024年第2期32卷 644-654页

作者： Yabei Xu Jiankun Shao wei Wang Shengliang Xu Dongping chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyXiangyang 441003China

The coupling effect of heat absorption and release exists in the thermal decomposition of a few chemical ***,the impact of the above coupling on thermal hazard assessment is not considered in the literature *** this work,nitroguanidine(NQ)and 1,3,5-trinitro-1,3,5-triazine(RDX)are selected as representative materials to explore the influence of the coupling effect on the thermal hazard assessment of chemical *** linear heating experiments of NQ and RDX are carried out by a microcalorimeter and synchronous thermal *** thermal decomposition curves are decoupled by advanced thermokinetics *** thermal decomposition and kinetic parameters before and after decoupling are *** results of Tg experiment show that both NQ and RDX began to lose mass during the endothermic *** endothermic melting and exothermic decomposition of NQ and RDX are coupled within this *** coupling effect has different degrees of influence on its initial decomposition temperature and safety *** with the parameters in the coupling state,the initial decomposition temperature and adiabatic induction period after decoupling *** self-accelerating decomposition temperature increases,and internal thermal runaway time *** the thermal hazard assessment of chemical materials with coupling effects,the calculated parameters after decoupling should be taken as an important safety index。

关键词： Calorimetric technologies Kinetics Thermal hazard Phase transformation Thermal decomposition

Nonlinear dynamics of a circular curved cantilevered pipe conveying pulsating fluid based on the geometrically exact model

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 261-276页

作者： Runqing CAO Zilong gUO wei chen Huliang DAI Lin WANg Department of Engineering Mechanics School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable *** fluid-structure interaction(FSI)between the pipe with a curved shape and the time-varying internal fluid flow brings a great challenge to the revelation of the dynamical behaviors of flexible pipes,especially when the pipe is highly flexible and usually undergoes large *** this work,the geometrically exact model(gEM)for a curved cantilevered pipe conveying pulsating fluid is developed based on the extended Hamilton's *** stability of the curved pipe with three different subtended angles is examined with the consideration of steady fluid *** attention is concentrated on the large-deformation resonance of circular pipes conveying pulsating fluid,which is often encountered in practical *** constructing bifurcation diagrams,oscillating shapes,phase portraits,time traces,and Poincarémaps,the dynamic responses of the curved pipe under various system parameters are *** mean flow velocity of the pulsating fluid is chosen to be either subcritical or *** numerical results show that the curved pipe conveying pulsating fluid can exhibit rich dynamical behaviors,including periodic and quasi-periodic *** is also found that the preferred instability type of a cantilevered curved pipe conveying steady fluid is mainly in the flutter of the second *** a moderate value of the mass ratio,however,a third-mode flutter may occur,which is quite different from that of a straight pipe system.

关键词： curved pipe conveying fluid pulsating fluid geometrically exact model(gEM) nonlinear dynamics parametric vibration flutter

Characterization of Fe-containing particles in chengdu,southwest China,using single-particle aerosol mass spectrometry

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Journal of Environmental Sciences 2024年第2期136卷 110-120页

作者： Renjiang He Junke Zhang Luyao chen wei Zhang Yingwei Xi School of Public Health Southwest Medical UniversityLuzhou 646000China Faculty of geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Sichuan Environmental Monitoring Center Chengdu 610074China

Single-particle aerosol mass spectrometry was used to study the characteristics of Fecontaining particles during winter in chengdu,southwest *** mass concentrations of PM_(2.5)and PM_(10)during the study period were 64±38 and 89±49μg/m~3,respectively,and NO_(2)and particulate matter were high compared with most other regions of *** Fecontaining particles were divided into seven categories with different mass spectra,sources and aging *** highest contribution was from Fe mixed with carbonaceous components(Fe-C,23.1%)*** was more mixed with sulfate than nitrate and therefore the contribution of Fe mixed with sulfate(Fe-S,20.7%)particles was higher than that of Fe mixed with nitrate(Fe-N,12.5%)*** contributions from Fe-containing particles related to primary combustion were high in the small particle size range,whereas aged Fecontaining particles and dust-related particles were mostly found in the coarse particle size *** air masses mainly originated from the west and east of chengdu,and the corresponding PM_(2.5)concentrations were 79±36 and 55±36μg/m~3,*** west and east air masses showed stronger contributions of Fe-containing particles related to biomass burning(Fe-B)and fossil fuel combustion(Fe-C and Fe-S)particles,*** southwest area contributed the most Fe-containing *** assessments of the effects of Fe-containing particles during heavy pollution period should pay more attention to Fe-C and Fe-S ***-reduction of Fe-containing particles should consider both local emissions and short-distance transmission from the surrounding areas.

关键词： Fe-containing particles Particle composition Potential source areas Evolution chengdu

Metal-to-insulator transitions in 3d-band correlated oxides containing Fe compositions

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 48-59页

作者： Yiping Yu Yuchen Cui Jianga.g He wei Mao Jikun chen Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Institute of Industrial Science The University of Tokyo4-6-1 KomabaMeguro-kuTokyo 153-8505Japan

Metal-to-insulator transitions (MITs),which are achieved in 3d-band correlated transitional metal oxides,trigger abrupt variations in electrical,optical,and/or magnetic properties beyond those of conventional *** such material families,iron(Fe:3d^(6)4s^(2))-containing oxides pique interest owing to their widely tunable MIT properties,which are associated with the various valence states of *** potential electronic applications also show promise,given the large abundance of Fe on *** MIT properties triggered by critical temperature (TMIT) were reported for ReFe_(2)O_(4)(Fe^(2.5+)),ReBaFe_(2)O_(5)(Fe^(2.5+)),Fe_(3)O_(4)(Fe^(2.67+)),Re_(1/3)Sr_(2/3)FeO_(3)(Fe^(3.67+)),Re Cu_(3)Fe_(4)O_(12)(Fe^(3.75+)),and Ca_(1-x)Sr_(x)FeO_(3)(Fe^(4+))(where Re represents rare-earth elements).The common feature of MITs of these Fe-containing oxides is that they are usually accompanied by charge ordering transitions or disproportionation associated with the valence states of ***,we review the material family of Fe-containing MIT oxides,their MIT functionalities,and their respective *** the perspective of potentially correlated electronic applications,the tunability of the TMITand its resultant resistive change in Fe-containing oxides are summarized and further compared with those of other materials exhibiting MIT *** particular,we highlight the abrupt MIT and wide tunability of TMITof Fe-containing quadruple perovskites,such as Re ***,their effective material synthesis still needs to be further explored to cater to potential applications.

关键词： metal-to-insulator transitions Fe-containing oxides charge ordering charge disproportionation

High-throughput microfluidic production of carbon capture microcapsules:fundamentals,applications,and perspectives

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International Journal of Extreme Manufacturing 2024年第3期6卷 330-361页

作者： Xiangdong Liu wei gao Yue Lu Liangyu Wu Yongping chen College of Electrical Energy and Power EngineeringYangzhou UniversityYangzhouJiangsu 225127People’s Republic of China Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjingJiangsu 210096People’s Republic of China Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application School of Environmental Science and EngineeringSuzhou University of Science and TechnologySuzhouJiangsu 215009People’s Republic of China

In the last three decades,carbon dioxide(CO_(2)) emissions have shown a significant increase from various *** address this pressing issue,the importance of reducing CO_(2) emissions has grown,leading to increased attention toward carbon capture,utilization,and storage *** these strategies,monodisperse microcapsules,produced by using droplet microfluidics,have emerged as promising tools for carbon capture,offering a potential solution to mitigate CO_(2) ***,the limited yield of microcapsules due to the inherent low flow rate in droplet microfluidics remains a *** this comprehensive review,the high-throughput production of carbon capture microcapsules using droplet microfluidics is focused ***,the detailed insights into microfluidic chip fabrication technologies,the microfluidic generation of emulsion droplets,along with the associated hydrodynamic considerations,and the generation of carbon capture microcapsules through droplet microfluidics are *** review highlights the substantial potential of droplet microfluidics as a promising technique for large-scale carbon capture microcapsule production,which could play a significant role in achieving carbon neutralization and emission reduction goals.

关键词： carbon capture microcapsules droplet microfluidic high-throughput production carbon neutralization

Energy budget of cold and hot gas-solid fluidized beds through CFD-DEM simulations

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Particuology 2024年第6期89卷 153-171页

作者： Lei Bi Yunpeng Jiao Chunjiang Liu Jianhua chen wei ge School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Direct energy budget is carried out for both cold and hot flow in gas–solid fluidization ***,the energy paths are proposed from thermodynamic *** consumption means total power input to the specific system,and it can be decomposed into energy retention and energy *** retention is the variation of accumulated mechanical energy in the system,and energy dissipation is the energy converted to heat by irreversible *** based on the Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)framework,different energy terms are quantified from the specific flow elements of fluid cells and particles as well as their interactions with the *** order to clarify the energy budget,it is important to identify which system is studied:the particle-fluid system or the particle *** the cold flow,the total energy consumption of the particle sub-system can well indicate the onset of bubbling and turbulent,while the variation of local energy consumption terms can reflect the evolution of heterogeneous *** the hot flow,different heat transfer mechanisms are analyzed and the solver is modified to reproduce the experimental *** impact of the heat transfer mechanisms and heat production on energy consumption is also *** proposed budget method has proven to be energy-conservative and easy to conduct,and it is hopeful to be applied to other multiphase flow systems.

关键词： Energy budget gas-solid fluidization CFD-DEM Regime transition Heat transfer mechanism

Promoted surface charge density from interlayer Zn–N_(4) configuration in carbon nitride for enhanced CO_(2) photoreduction

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Nano Research 2024年第4期17卷 2400-2409页

作者： Xianjin Shi Yu Huang ga.gqiang Zhu wei Peng Meijuan chen State Key Laboratory of Loess and Quaternary geology(SKLLQg) Key Laboratory of Aerosol Chemistry and PhysicsInstitute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Center of Excellence in Quaternary Science and global Change Chinese Academy of SciencesXi’an 710061China University of Chinese Academy of Sciences Beijing 100049China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China

The solar-driven reduction of CO_(2) into valuable products is a promising method to alleviate global environmental problems and energy ***,the low surface charge density limits the photocatalytic conversion performance of CO_(2).Herein,a polymeric carbon nitride(PCN)photocatalyst with Zn single atoms(Zn1/CN)was designed and synthesized for CO_(2) *** results of the CO_(2) photoreduction studies show that the CO and CH_(4) yields of Zn1/CN increased fivefold,reaching 76.9 and 22.9μmol/(g·h),respectively,in contrast to the unmodified ***+plasma-etched X-ray photoelectron spectroscopy and synchrotron radiation-based X-ray absorption fine structure results reveal that Zn single atom is mainly present in the interlayer space of PCN in the Zn–N_(4) *** characterizations indicate that the interlayer Zn–N_(4) configuration can amplify light absorption and establish an interlayer charge transfer ***-assisted Kelvin probe force microscopy confirms that more photogenerated electrons are delivered to the catalyst surface through interlayer Zn–N_(4) configuration,which increases its surface charge ***,in-situ infrared spectroscopy combined with density functional theory calculation reveals that promoted surface charge density accelerates key intermediates(*COOH)conversion,thus achieving efficient CO_(2) *** work elucidates the role of internal single atoms in catalytic surface reactions,which provides important implications for the design of single-atom catalysts.

关键词： single-atom catalysts photocatalytic CO_(2)reduction interlayer modification charge transfer dynamics surface charge density

Time-synchronous-averaging-spectrum based on super-resolution analysis and application in bearing fault signal identification

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 573-585页

作者： Zengle REN Yuan WANg Huiyue TANg Xin'an chen wei FENg guangdong Provincial Key Laboratory of Construction Robotics and Intelligent Construction Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China Shenzhen EBORAIL Technology Co. Ltd.Shenzhen518038China National Supercomputing Center in Shenzhen Shenzhen518055China State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing100044China University of Chinese Academy of Sciences Beijing100190China Shenzhen University of Advanced Technology Shenzhen518107China

Time-synchronous-averaging(TSA)is based on the idea of denoising by averaging,and it extracts the periodic components of a quasiperiodic signal and keeps the extracted waveform *** paper studies the mathematical properties of TSA,where three propositions are given to reveal the nature of *** paper also proposes a TSA-spectrum based on super-resolution analysis and it decomposes a signal without using any base *** contrast to discrete Fourier transform spectrum(DFT-spectrum),which is a spectrum in frequency domain,TSA-spectrum is a period-based spectrum,which can present more details of the cross effects between different periodic components of a quasiperiodic ***,a case study is carried out using bearing fault analysis to illustrate the performance of TSA-spectrum,where the rotation speed fluctuation of the shaft is estimated,which is about 0.12 ms *** extracted fault signals are presented and some insights are *** believe that this paper can provide new motivation for TSA-spectrum to be widely used in applications involving quasiperiodic signal processing(QSP).

关键词： Time-synchronous-averaging(TSA) Spectrum Quasiperiodic signal processing(QSP) Super-resolution analysis Bearingfaultdetection

Regulatable Orthotropic 3D Hybrid Continuous Carbon Networks for Efficient Bi-Directional Thermal Conduction

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Nano-Micro Letters 2024年第10期16卷 136-148页

作者： Huitao Yu Lianqiang Peng Can chen Mengmeng Qin wei Feng School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin 300350People's Republic of China

Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer efficiency of vertically oriented carbon structures is a challenging ***,an orthotropic three-dimensional(3D)hybrid carbon network(VSCg)is fabricated by depositing vertically aligned carbon nanotubes(VACNTs)on the surface of a horizontally oriented graphene film(HOgF).The interfacial interaction between the VACNTs and HOgF is then optimized through an annealing *** regulating the orientation structure of the VACNTs and filling the VSCg with polydimethylsi-loxane(PDMS),VSCg/PDMS composites with excellent 3D thermal conductive properties are *** highest in-plane and through-plane thermal conduc-tivities of the composites are 113.61 and 24.37 W m^(-1)K^(-1),*** high contact area of HOgF and good compressibility of VACNTs imbue the VSCg/PDMS composite with low thermal *** addition,the interfacial heat-transfer efficiency of VSCg/PDMS composite in the TIM performance was improved by 71.3%compared to that of a state-of-the-art thermal *** new structural design can potentially realize high-performance TIMs that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.

关键词： Orthotropic continuous structures Hybrid carbon networks Carbon/polymer composites Thermal interface materials

Optimal Planning of Hybrid AC/DC Low-voltage Distribution Networks Considering DC Conversion of Three-phase Four-wire Low-voltage AC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 141-153页

作者： Bo Zhang Lu Zhang wei Tang gen Li chen Wang the College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China the Electric Energy group Department of Engineering TechnologyTechnical University of Denmark(DTU)2750 BallerupDenmark the Power Distribution Technology Center State Grid Beijing Electric Power Research InstituteBeijing 100075China

The increasing integration of distributed household photovoltaics(PVs)and electric vehicles(EVs)may further ag gravate voltage violations and unbalance of low-voltage distribu tion networks(LVDNs).DC distribution networks can increase the accommodation of PVs and EVs and mitigate mutilple pow er quality problems by the flexible power regulation capability of voltage source *** paper proposes schemes to es tablish hybrid AC/DC LVDNs considering the conversion of the existing three-phase four-wire low-voltage AC systems to DC op *** characteristics and DC conversion constraints of typical LVDNs are *** addition,converter configura tions for typical LVDNs are proposed based on the three-phase four-wire characteristics and quantitative analysis of various DC ***,an optimal planning method of hybrid AC/DC LVDNs is proposed,which is modeled as a bi-level programming model considering the annual investments and three-phase *** are conducted to verify the effectiveness of the proposed optimal planning *** ulation results show that the proposed optimal planning method can increase the integration of PVs while simultaneously reduc ing issues related to voltage violation and unbalance.

关键词： Optimal planning low-voltage distribution net work three-phase unbalance DC conversion