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Journal of Central South University 2024年第6期31卷 1931-1944页

作者： XIE Su-chao HE Lei YAN Hong-yu ZHANG Feng-yi HE Guan-di WANG Jia-cheng Key Laboratory of Traffic safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha 410075China joint International research Laboratory of Key technology for rail Traffic safety Changsha 410075China national&local joint engineering research center of safety technology for rail vehicle Changsha 410075China

In order to overcome the limitations of traditional microperforated plate with narrow sound absorption bandwidth and a single structure,two multi-cavity composite sound-absorbing materials were designed based on the shape of monoclinic crystals:uniaxial oblique structure(UOS)and biaxial oblique structure(BOS).Through finite element simulation and experimental research,the theoretical models of UOS and BOS were verified,and their sound absorption mechanisms were *** the same time,the influence of multi-cavity composites on sound absorption performance was analyzed based on the theoretical model,and the influence of structural parameters on sound absorption performance was *** research results show that,in the range of 100-2000 Hz,UOS has three sound absorption peaks and BOS has five sound absorption *** frequency range of the half-absorption bandwidth(α>0.5)of UOS and BOS increases by 242% and 229%,*** with traditional microperforated sound-absorbing structures,the series and parallel hybrid methods significantly increase the sound-absorbing bandwidth of the sound-absorbing *** research has guiding significance for noise control and has broad application prospects in the fields of transportation,construction,and mechanical design.

关键词： monoclinic crystal microperforated plate acoustic metamaterials inclined cavity sound absorption

Numerical simulation of formaldehyde distribution characteristics in the high-speed train cabin

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Building Simulation 2024年第2期17卷 285-300页

作者： Fan Wu Hang Dong Chao Yu Hengkui Li Qingmin Cui Renze Xu Key Laboratory of Traffic safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangshaHunan410075China joint International research Laboratory of Key Technologies for rail Traffic safety ChangshaHunan410075China national&local joint engineering research center of safety technology for rail vehicle ChangshaHunan410075China School of Software Henan University of EngineeringZhengzhouHenan451191China

The global concern over indoor air pollution in public vehicles has grown *** a focus on enhancing passengers’comfort and health,this study endeavors to investigate the distribution characteristics of formaldehyde within a high-speed train cabin by employing a computational fluid dynamics(CFD)model which is experimentally validated in a real cabin *** research focuses on analyzing the impact of air supply modes,temperature,relative humidity,and fresh air change rate on the distribution and concentration of *** results demonstrate that the difference in average formaldehyde concentration between the two air supply modes is below 1.3%,but the top air supply mode leads to a higher accumulation of formaldehyde near the sidewalls,while the bottom air supply mode promotes a more uniform distribution of ***,the temperature,relative humidity,and fresh air change rate are the primary factors affecting formaldehyde concentration levels,but they have modest effects on formaldehyde’s distribution pattern within the *** the temperature and relative humidity increase,the changes in formaldehyde concentrations in response to variations in these factors become more ***,the formaldehyde concentration may surpass the standard limit of 0.10 mg/m^(3)if the fresh air change rate falls below 212 m^(3)/*** research provides a systematic approach and referenceable results for exploring formaldehyde pollution in high-speed train cabins.

关键词： indoor air pollution formaldehyde CFD simulation high-speed train ventilation

PdCu alloy anchored defective titania for photocatalytic conversion of carbon dioxide into methane with 100% selectivity

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Journal of Energy Chemistry 2024年第4期91卷 254-265页

作者： Lina Zhang Sajjad Hussain Qiuye Li Jianjun Yang national&local joint engineering research center for Applied technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004HenanChina

The photoreduction of CO_(2)into CH_(4)with simultaneous high activity and selectivity is a promising strategy to increase energy supply and alleviate global ***,the absence of the active sites that is responsible for the adsorption and activation of CO_(2)and the generation of CO and H2via side reactions often lead to poor efficiency and low selectivity of the ***,Cu,Pd,and PdCu metal clusters cocatalyst-anchored defective TiO_(2)nanotubes(Cu/TiO_(2)-SBO,Pd/TiO_(2)-SBO,and Pd1Cu1/TiO_(2)-SBO)were designed via a simple solution impregnation reduction and applied for photocatalytic conversion of CO_(2)to CH_(4).The Pd1Cu1/TiO_(2)-SBO photocatalyst exhibits excellent catalytic performance among the other catalysts for photoreduction of CO_(2)into CH_(4).More interestingly,the product selectivity of CH_(4)reaches up to 100%with a rate of 25μmol g^(-1)h^(-1).In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and density functional theory(DFT)simulations indicate that the main reasons for the high selectivity of CH_(4)are attributed to the PdCu alloy and oxygen vacancies,which jointly enhance the photoinduced carrier separation and lower energy barriers of key ***,due to the tunable d-band center of the Cu site in the PdCu alloy,the generated intermediates can be well prevented from poisoning and promoted to participate in further ***,the current study will provide insight into the development of new,highly selective photocatalysts for the visible light-catalytic reduction of CO_(2)into CH_(4).

关键词： PdCu alloy Defective TiO_(2) Photoreduction of CO_(2) Photocatalytic mechanism

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Surface structural transformation of Ni2P@C electrocatalysts for overall alkaline water splitting

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Progress in Natural Science:Materials International 2024年第1期34卷 102-107页

作者： Kun Yang Xinjuan Liu Jun Xu Yun Gong Shuling Shen Jinchen Fan Xiaojie Zhang Yuhua Xue School of Materials and Chemistry University of Shanghai for Science and Technology national&local joint engineering research center for Mineral Salt Deep Utilization Huaiyin Institute of Technology

Understanding the surface restructuring, including atomic rearrangement and chemical composition adjustments,is urgent to accelerate electrocatalytic reactions. Herein, we focus on the surface restructuring and active species for phosphide especially Ni2P during the water splitting process by combination of in-situ Raman and ex-situ X-ray photoelectron spectroscopy. Results confirm that NiOOH and NiOO* are formed during OER, while Niδ+-Hadactive sites are formed during HER. In situ-formed NiOOH/Ni2P@C and Niδ+/Ni2P@C show enhanced water splitting（1.514 V at 10 mA/cm2） and NO3RR(86% and 668 μmol h-1cm-2for NH3Faraday efficiency and yield)activities. In-depth investigation of the surface dynamic changes can provide guidance for establishing the relation of structure-electrocatalytic activity.

关键词： Dynamic surface restructuring Phase structural transition In-situ Raman spectra Ni_2P@C Overall water splitting

EBSD analysis of grain boundary evolution and dynamic recrystallization of Inconel 625 superalloy at various hot spinning feed rates

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Progress in Natural Science:Materials International 2024年第1期34卷 56-65页

作者： Zhanjie Jing Jiangkun Fan Xudong Liu Yuelin Song Zixiao Wang Kai Cao Yuetan Chen Heng Fu Jianing Zhang Jinshan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Chongqing Innovation center Northwestern Polytechnical University national&local joint engineering research center for Precision Thermoforming technology of Advanced Metal Materials

Hot spinning can make the material withstand shear stress, so that the shape of the material has a great change,which is one of the main processing methods of nickel-based alloy plate members. Inconel 625 alloy, which has excellent high temperature mechanical properties and can be used as the main candidate material for aerospace applications, needs further study on its hot spinning deformation behavior and deformation mechanism. In this paper, the effect of feed rate on the microstructure evolution of Inconel 625 superalloy was studied by the electron backscattered diffraction technology. The microstructure with necklace-like structures composed of dynamic recrystallization(DRX) grains was observed after hot spinning. It was found that at the low feed rate, the promotion of DRX degree and grain refinement happened, where the grain size reached the trough of 10.99 μm under a feed rate of 300 mm/min. However, with the further feed rate rising, the degree of DRX was suppressed to a certain extent and grain size increased to 14.26 μm. On balance, the feed rate of 300 mm/min was the most efficient condition for grain refinement. Besides, it was revealed that both discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) occurred during hot spinning. DDRX includes the initial grain boundary nucleation by bulging and the annealing twin boundary assisted nucleation, while the CDRX mechanism is related to the continuous subgrain rotation within the deformed grain. DDRX is the main DRX mechanism.

关键词： Inconel 625 superalloy Hot spinning Grain boundary evolution DRX mechanism

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

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Nano research 2024年第3期17卷 1666-1675页

作者： Cuiping Li Lu Zhang Shuai Zhang Qiqi Yu Dan Li Lei Zhang Chunhong Gong Jingwei Zhang Institute of Functional Polymer Composites College of Chemistry and Molecular SciencesHenan UniversityKaifeng 475004China national&local joint engineering research center for Applied technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature ***,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about ***,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of ***,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on *** hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated *** from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 *** work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

关键词： flexible titanium nitride nanofibrous membranes local conductive loss dielectric loss electromagnetic microwave absorption wide temperature spectrum

Quantitative measurement and application of droplets on physical surfaces based on LIF technology

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Transportation safety and Environment 2024年第2期6卷 104-113页

作者： Fan Wu Shuaixiong Zhou Qingmin Cui Renze Xu Hengkui Li Chao Yu Key Labor atory of Traffic safety on Track of Ministry of Education School of Traffic&Transportation EngineeringCentr al South Univ ersityChangsha 410075HunanChina joint International research Laboratory of Key Technologies for rail Traffic safety School of Traffic&Transportation EngineeringCentral South UniversityChangsha 410075HunanChina School of software Henan University of EngineeringZhengzhou 451191HenanChina national&local joint engineering research center of safety technology for rail vehicle School of Traffic&Transportation EngineeringCentral South UniversityChangsha 410075HunanChina

Contaminated surfaces play a significant role in the transmission of respiratory infectious *** address this issue,we pre-sented a novel quantitative detection method for droplets on physical surfaces,based on the laser-induced fluorescence *** proposed detection method was demonstrated in a realistic high-speed train compartment scenario by simulating the process of droplet release during passengers’breathing and *** experimental results showed that this method could offer high precision(10-1 mg/m^(2))for detecting minute substance concentrations,and its ease of operation makes it suitable for complex en-gineering *** results also revealed that under the combined effects of the indoor airflow and breathing airflow,the range of droplets released by breathing activity exceeded two rows in front of and behind the release ***,we observed that a large number of droplets settled on the seat surfaces on both sides of the same row as the releaser,with over 36%of these droplets concentrated on the backrest area of the *** the respiratory jet velocity increased,the location with the most sed-iment droplets(accounting for 8%of the total sedimentation)occurred on the seat directly in front of the releaser,and approximately 48% of the droplets were found on the back of this *** proposed method overcomes the shortcomings of existing experimental methods in quantitatively capturing the motion characteristics of droplets in complex flow fields.

关键词： quantitative measurement sediment droplets physical surfaces fluorescence measurement high-speed train compart-ment

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Complementary multicolor electrochromic devices with excellent stability based on porous tin oxide nanosheet scaffold

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Nano research 2024年第4期17卷 3035-3042页

作者： Chenchen Bian Jinhui Wang Huanhuan Liu Yin Yan Ping Zhang Weilong Yang Sensen Jia Xiaodan Guo Guofa Cai Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Center for High-Efficiency Display and Lighting TechnologySchool of Materials and Engineeringand Collaborative Innovation Center of Nano Functional Materials and ApplicationsHenan UniversityKaifeng 475004China

Electrochromic devices(ECDs)have been extensively investigated as promising candidates in broad cutting-edge applications,such as smart windows,electronic labels,adaptive camouflage,***,they have suffered from either inadequate color variations or poor cycling stability for a long ***,we developed a general strategy to boost the cyclic stability and enrich the color variations of ECDs by scrupulous design of the composition and nanostructure of electrodes,in which porous tin oxide(SnO_(2))nanosheets serve as the scaffold and typical metal oxides or conducting polymers as the active electrochromic *** electrochromic composite materials,including polyaniline(PANI)@SnO_(2),V2O5@SnO_(2),and WO_(3)@SnO_(2) heterostructured nanoarrays were prepared by the facile wet-chemical *** composite electrodes exhibit remarkable electrochromic performances,e.g.,superior cycling stability(more than 2000 cycles),rich color variations(more than 5 colors for PANI@SnO_(2)),and enlarged optical *** excellent performances account for the heterogenous porous nanoarrays,which not only facilitate the intercalation/extraction of ions but also relieve the stress generated during the electrochemical *** addition,diverse prototypes of complementary multicolor ECD with excellent cycling stability(over thousands of cycles)and rich color variations(8 colors)were realized for the first *** believe that our work put forward a general strategy for developing high-quality multicolor complementary electrochromic devices.

关键词： electrochromism tin oxide metal oxide cycling stability multicolor complementary device

High-brightness green InP-based QLEDs enabled by in-situ passivating core surface with zinc myristate

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Materials Futures

Materials Futures 2024年第2期3卷 141-148页

作者： Yuanbin Cheng Qian Li Mengyuan Chen Fei Chen Zhenghui Wu Huaibin Shen Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Center for High-efficiency Display and Lighting TechnologyHenan UniversityKaifeng 475004People’s Republic of China

The performance of red InP and blue ZnTeSe-based quantum dots(QDs)and corresponding QD light emitting diodes(QLEDs)has already been improved significantly,whose external quantum efficiencies(EQEs)and luminances have exceeded 20%and 80000 cd m-2,***,the inferior performance of the green InP-based device hinders the commercialization of full-color Cd-free QLED *** ease of oxidation of the highly reactive InP cores leads to high non-radiative recombination and poor photoluminescence quantum yield(PL QY)of the InP-based core/shell QDs,limiting the performance of the relevant ***,we proposed a fluoride-free synthesis strategy to in-situ passivate the InP cores,in which zinc myristate reacted with phosphine dangling bonds to form Zn–P protective layer and protect InP cores from the water and oxygen in the *** resultant InP/ZnSe/ZnS core/shell QDs demonstrated a high PL QY of 91%.The corresponding green-emitting electroluminescence devices exhibited a maximum EQE of 12.74%,along with a luminance of over 175000 cd m^(-2)and a long T50@100 cd m^(-2)lifetime of over 20000 h.

关键词： quantum-dot light emitting diodes InP-based quantum dot in-situ passivation of core surface zinc myristate

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane oxidation with molecular oxygen and the active sites investigation

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Frontiers of Chemical Science and engineering 2024年第3期18卷 101-112页

作者： Lei Chen Yuan Sun Jinshan Chi Wei Xiong Pingle Liu Fang Hao College of Chemical engineering National&Local United Engineering Research Centre for Chemical Process Simulation and IntensificationXiangtan UniversityXiangtan411105China

The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical *** present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%***,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency ***,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin *** achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under *** results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the *** addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)*** this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.

关键词： KA oil production cyclohexane selective oxidation cobalt-nitrogen co-doped porous carbon spheres metal-organic framework