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Chinese Journal of Chemical Engineering 2024年第2期66卷 40-50页

作者： Yi-Fei Liang jin-Rong Lu Shang-Kun Tian Wen-Quan Cui Li liu Hebei Provincial Key Laboratory of Environmental Photocatalytic and Electrocatalytic Materials College of Chemical EngineeringNorth China University of Science and TechnologyTangshan 063210China

For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild *** attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of *** improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced *** catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes *** addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and *** study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.

关键词： Water reforming of methanol Photocatalysis g-C_(3)N_(4) Pt nanoclusters Hydrogen production

Size-dependent thermomechanical vibration characteristics of rotating pre-twisted functionally graded shear deformable microbeams

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1015-1032页

作者： Songye jin Bo ZHANG Wuyuan ZHANG Yuxing WANG Huoming SHEN jing WANG Juan liu School of Mechanics and Aerospace Engineering Southwest Jiaotong UniversityChengdu 610031China School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China School of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu 610500China

A three-dimensional(3D)thermomechanical vibration model is developed for rotating pre-twisted functionally graded(FG)microbeams according to the refined shear deformation theory(RSDT)and the modified couple stress theory(MCST).The material properties are assumed to follow a power-law distribution along the chordwise *** model introduces one axial stretching variable and four transverse deflection variables including two pure bending components and two pure shear *** complex modal analysis and assumed mode methods are used to solve the governing equations of motion under different boundary conditions(BCs).Several examples are presented to verify the effectiveness of the developed *** coupling the slenderness ratio,gradient index,rotation speed,and size effect with the pre-twisted angle,the effects of these factors on the thermomechanical vibration of the microbeam with different BCs are *** is found that with the increase in the pre-twisted angle,the critical slenderness ratio and gradient index corresponding to the thermal instability of the microbeam increase,while the critical material length scale parameter(MLSP)and rotation speed *** sensitivity of the fundamental frequency to temperature increases with the increasing slenderness ratio and gradient index,and decreases with the other increasing ***,the size effect can suppress the dynamic stiffening effect and enhance the Coriolis ***,the mode transition is quantitatively demonstrated by a modal assurance criterion(MAC).

关键词： thermomechanical vibration rotating pre-twisted functionally graded(FG)microbeam refined shear deformation theory(RSDT) modified couple stress theory(MCST) modal assurance criterion(MAC)

Experimental and numerical study of combustion characteristics of ammonia-hydrogen-air swirling flame with/without secondary air injection

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Chinese Journal of Aeronautics 2024年第4期37卷 243-255页

作者： Chunyu liu Chenhu GAO Yue HUANG Hua jin Dan ZHAO Wenjiang XU Yancheng YOU School of Aerospace Engineering Xiamen UniversityXiamen 361005China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering University of CanterburyChristchurch 8041New Zealand

Ammonia (NH_(3)) is currently considered to be a potential carbon-free alternative fuel,and its large-scale use as such would certainly decrease greenhouse gas emissions and meet increasingly stringent emission *** the low flame propagation speed and high NO production of NH_(3) hinder its direct application as a renewable fuel,co-combustion of NH_(3)–H_(2)is an effective way to overcome these *** this study,the combustion characteristics of NH_(3)–H_(2)swirling flames under different equivalence ratios and H_2blending ratios conditions are both numerically and experimentally ***,the One-Dimensional (1D) laminar flame computation presents a comparison base and the Three-Dimensional (3D) numerical simulation yields detailed flame property ***,the high-speed camera takes instantaneous swirl flame images and the gas analyzer measures the NO emission at the exit plane of the flame *** and quantitative analysis is performed on the flame structure and NO emission for a series of NH_(3)–H_(2)swirl *** variation trends of the NO emission calculated using different techniques agree very *** quantitative results show that the NO emissions are much higher at lean equivalence ratios than those at rich equivalence ratios,and such difference is closely related to the combustion flame ***,it is shown that the utilization of secondary air injection can achieve a significant reduction in NO emissions at the exit of the combustion chamber at equivalence ratios less than or equal to 0.9.

关键词： Ammonia combustion Swirling flow NO emission characteristics Secondary combustion Chemical reaction mechanism

Selective cyclohexane oxidation enhancement by electronic structures regulation of metal-poly(ionic liquid)s

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Green Chemical Engineering 2024年第2期5卷 213-221页

作者： Ying jin Shengxin Chen Ruirui Wang Yumei liu Xinxin Li Yingwei Li Ruirui Zhang Ruixia liu Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou450001China Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringInnovation Academy for Green ManufactureCASBeijing100190China

Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in *** this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of *** analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial *** with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil *** interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the ***,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.

关键词： Metal-PILs Cyclohexane oxidation C-H activation Co-N sites

A Composite Elastomer with Photo-responsive Shape Memory and Programmable Hygroscopic Actuation Functionalities

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Chinese Journal of Polymer Science 2024年第10期42卷 1470-1478页

作者： Xiang-Xi Cui Li Shang Zhong-Wen liu Zhao-Tie liu jin-Qiang Jiang Guo Li Key Laboratory of Syngas Conversion of Shaanxi Province School of Chemistry and Chemical Engineering Shaanxi Normal University

Developing hydroscopic actuators with simultaneous high elasticity, shape programmability and tunable actuating behaviors are highly desired but still challenging. In this study, we propose an orthogonal composite design to develop such a material. The developed composite elastomer comprises carboxyl group-grafted polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene(SEBS-g-COOH) as the elastic substrate, and a synthesized azobenzene derivative as the functional filler(Azo12). By surface treatment using acidic and base solutions, the carboxyl groups on the surface can reversibly transform into carboxylate groups, which render the composite tunable hygroscopic actuating functionality. On another aspect, the added filler undergoes trans-to-cis isomerization when exposed to UV light irradiation, leading to liquefaction of the crystalline aggregates formed by Azo12 molecules. The liquefied Azo12 molecules can autonomously resotre their trans form and reform the crystalline structure. This reversible change in crystralline structure is utilized to realize the shape memory property, and 5 wt% of Azo12addition is adequate for the composite to exhibit photo-responsive shape memory behavior without compromising much of the elasricity. The regualtion of external geometry by shape memory effect is effective in altering the actuating behavior. The proposed method can be extend to designing different composites with the demonstrated functionalities.

关键词： Actuator Azobenzene Hygroscopic responsive Photo-responsive Shape memory

Vanadium nitride quantum dots@carbon skeleton anode material synthesized via in situ oxidation initiation strategy

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Tungsten 2024年第3期6卷 561-573页

作者： Yi-Han Fu Yuan-You Peng Lei Zhao Tian-Qi He Mei-Mei Yuan Hao Dang Rui liu fen Ran State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals School of Materials Science and Engineering Lanzhou University of Technology

Vanadium nitride（VN） has received significant attention as a potential negative electrode material due to its remarkable theoretical and physical ***,the electrochemical performance needs to be improved due to its low specific surface area and the issue of being easily dissolved in *** have shown that the composite structure of carbon-coated nano sc ale VN particles could significantly increase the specific surface area of VN,and more importantly,and the carbon matrix can effectively restrain the dissolution of VN particles in the electrolyte,thereby improving its chemical and electrochemical performance,including specific capacity and cycling ***,VN quantum dots are synthesized and protected by uniformly coating the carbon skeleton on its surface via an in situ strategy of oxidation initiation,which initiates dopamine polymerization,forming a crystalline complex of polydopamine and *** heat treatment,the product is a composite material with VN quantum dots embedded in the amorphous carbon *** resulting smallsized and crosslinked carbon particles formed a graded pore structure,more reasonable channels provided for electrolyte ions transport *** the composite material was used as the negative electrode material for supercapacitors,it exhibits the specific capacity of 391.9 F·g-1at a current density of 0.5 A·g-1and excellent capacity retention rate of 83.6% after *** synthesis method of this quantum dot could be applied to other metal compounds and has potential applications in catalysis,environmental protection,and other fields.

关键词： In situ initiation Vanadium nitride Quantum dots Anode Supercapacitors

Dynamic access task scheduling of LEO constellation based on space-based distributed computing

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Journal of Systems Engineering and Electronics 2024年第4期35卷 842-854页

作者： liu Wei jin Yifeng ZHANG Lei GAO Zihe TAO Ying Institute of Telecommunication and Navigation Satellites China Academy of Space TechnologyBeijing 100094China Innovation Center of Satellite Communication System China National Space AdministrationBeijing 100094China

A dynamic multi-beam resource allocation algorithm for large low Earth orbit(LEO)constellation based on on-board distributed computing is proposed in this *** allocation is a combinatorial optimization process under a series of complex constraints,which is important for enhancing the matching between resources and requirements.A complex algorithm is not available because that the LEO on-board resources is *** proposed genetic algorithm(GA)based on two-dimen-sional individual model and uncorrelated single paternal inheri-tance method is designed to support distributed computation to enhance the feasibility of on-board application.A distributed system composed of eight embedded devices is built to verify the algorithm.A typical scenario is built in the system to evalu-ate the resource allocation process,algorithm mathematical model,trigger strategy,and distributed computation *** to the simulation and measurement results,the proposed algorithm can provide an allocation result for more than 1500 tasks in 14 s and the success rate is more than 91%in a typical *** response time is decreased by 40%com-pared with the conditional GA.

关键词： beam resource allocation distributed computing low Earth obbit(LEO)constellation spacecraft access task scheduling

Preventive effects of Bifidobacterium lactis Probio-M8 on ovalbumin-induced food allergy in mice

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Food Science and Human Wellness 2024年第4期13卷 2346-2352页

作者： Jialu Shi Yan Xu Cheng liu Shizhi Wang jin Wang Vijaya Raghavan Key Laboratory of Environmental Medicine and Engineering Ministry of Educationand Department of Nutrition and Food HygieneSchool of Public HealthSoutheast UniversityNanjing 210009China Department of Bioresource Engineering Faculty of Agricultural and Environmental SciencesMcGill UniversitySainte-Anne-de-BellevueQC H9X3V9Canada

Food allergy is a significant public health concern *** probiotics have been found to enhance food allergy by regulating immune-microbe interactions in animal models and ***,the effects of Bifidobacterium lactis Probio-M8 on food allergy have not been thoroughly *** present study examined the anti-allergic properties of Probio-M8,particularly in relation to immune response and gut microbiota *** demonstrate that oral administration of Probio-M8 effectively mitigated the allergy symptoms triggered by ovalbumin(OVA)by ameliorating the morphological damage in the jejunum,reducing OVA-specific IgE and histamine levels in the serum,and suppressing Th2 cytokines(interleukin(IL)4 and IL-13)while increasing Th1 cytokines(interferon(IFN)γ)and regulatory T(Treg)cytokines(IL-10 and transforming growth factor(TGF)β1)in the culture supernatants of splenic ***,Probio-M8 effectively altered the diversity and composition of gut microbiota,particularly the relative abundances of Akkermansia_muciniphila in OVA-induced *** to the OVA group,the Probio-M8 group showed a decrease in the relative abundance of Akkermansia_*** conclusion,Probio-M8 demonstrates the potential to alleviate food allergy by regulating the Th1/Th2 response and modulating gut microbiota,thereby offering a novel therapeutic strategy for patients with food allergy.

关键词： Food allergy Bifidobacterium lactis Probio-M8 T cell immune response Gut microbiota

Flame Structure of Methane and Kerosene Combustion with a Compact Concave Flame-Holder using the LES-pdf Method

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Journal of Thermal Science 2024年第1期33卷 222-234页

作者： WANG Fang WANG Yunfan WEI Guanyi liu Denghuan jin Jie JONES P.William School of Energy and Power Engineering Beihang UniversityBeijingBeijing 100191China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Compact flame-holders for afterburners are an increasing requirement for modern aero ***,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex turbulence,combustion,and spray coupling in modern *** this work,the LES-pdf and stochastic fields-Lagrangian particle spray methods are used to investigate methane and aviation kerosene combustion structures formed by new-type concave *** flow pattern,combustion mode,and flame structure of gaseous and liquid fuel around a concave flame-holder are analyzed,discussed,and compared with experimental *** reveal that the flame stability of a concave flame-holder is better than that of the non-concave ***,when using liquid fuel,the concave flame-holder forms a stable and compact *** results suggest concave flame-holders are a promising design for compact afterburners.

关键词： concave structure flame-holder LES-pdf spray combustion flame structure AECSC

Investigation of the block toppling evolution of a layered model slope by centrifuge test and discrete element modeling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 112-122页

作者： Leilei jin Hongkai Dong Fei Ye Yufeng Wei Jianfeng liu Changkui Wang State Key Laboratory of Hydraulic and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China

Primary toppling usually occurs in layered rock slopes with large anti-dip *** this paper,the block toppling evolution was explored using a large-scale centrifuge *** block column in the layered model slope was made of cement *** artificial cracks perpendicular to the block column were *** gages,displacement gages,and high-speed camera measurements were employed to monitor the deformation and failure processes of the model *** centrifuge test results show that the block toppling evolution can be divided into seven stages,*** compression,formation of major tensile crack,reverse bending of the block column,closure of major tensile crack,strong bending of the block column,formation of failure zone,and complete *** toppling is characterized by sudden large deformation and occurs in *** wedge-shaped cracks in the model incline towards the *** observations show that block toppling is mainly caused by bending failure rather than by shear *** tensile strength also plays a key factor in the evolution of block *** simulation results from discrete element method(DEM)is in line with the testing *** stress exists at the backside of rock column during toppling *** concentration results in the fragmented rock column and its degree is the most significant at the slope toe.

关键词： Block toppling Centrifuge Anti-dip slope Failure mechanism Discrete element method