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Porous silica nano-flowers stabilized Pt-Pd bimetallic nanoparticles as heterogeneous catalyst for efficiently synthesizing guaiacol from 2-methoxycyclohexanol

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Chinese Journal of Chemical engineering 2024年第6期70卷 222-233页

作者： Junbo Feng Junyan Wu Dongdong Yan Yadong Zhang School of Chemical engineering Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Coking coal Exploitation and Comprehensive Utilization Pingdingshan 467000China Jiyuan research institute Zhengzhou UniversityJiyuan 459000China School of Materials and Chemical engineering Zhongyuan University of TechnologyZhengzhou 450007China

Porous silica nano-flowers(KCC-1)immobilized Pt-Pd alloy NPs(Pt-Pd/KCC-1)with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction,using hydrazinium hydroxide as a reducing *** as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm,exhibiting a high specific surface area(443.56 m^(2)·g^(-1)).Meanwhile,the obtained Pt-Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4-6 nm,which exist as metallic Pd and Pt on the surface of monodisperse KCC-1,showing the transfer of electrons from Pd to *** as-synthesized 2.5%Pt-2.5%Pd/KCC-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare *** with Pt or Pd single metal supported catalysts,the obtained 2.5%Pt-2.5%Pd/KCC-1 shows 97.2%conversion rate of 2-methoxycyclohexanol and 76.8%selectivity for guaiacol,which attributed to the significant synergistic effect of bimetallic Pt-Pd alloy ***,turn over frequency value of the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s^(-1),showing higher catalytic efficiency than other two monometallic *** pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are ***,the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol,while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green,outstanding and powerful synthetic pathway of guaiacol.

关键词： Supported catalyst Nanoparticles Dehydrogenation 2-Methoxycyclohexanol Guaiacol

Improving flangeability of multiphase steel by increasing microstructural homogeneity

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Journal of Iron and Steel research(International) 2024年第7期31卷 1736-1745页

作者： Xiao-yu Yang Yong-gang Yang Xing Fang Han-long Zhang Zhen-li Mi Beijing Advanced Innovation Center for Materials Genome engineering Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Shanghai Baosteel group Corp.technology Center Shanghai 201900China

Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstructural homogeneity was advanced by adjusting the hard martensite/austenite(M/A)*** strength-flangeability was measured via uniaxial tensile tests and hole expansion *** microstructures were characterized using a scanning electron microscope equipped with an electron backscatter diffraction detector and a transmission electron *** tests were supplementally used to quantitatively reveal the microstructural homogeneity of the *** show that the adjusted multiphase steel achieves an excellent ultimate tensile strength(~800 MPa)and flangeability(~135%hole expansion ratio).A promising homogeneous multiphase microstructure was obtained by controlling undercooled austenite transformed at about 600℃.This microstructure consists of soft polygonal ferrite,blocky bainitic ferrite,and hard M/A *** volume fraction of M/A islands is around 5%,and the average size is less than l *** nanoindentation analysis indicated that the participation of M/A islands impressively influenced the microstructural *** strain partition and better mechanical compatibility were present in the adjusted multiphase steel since the plasticity initiation started late,which resulted in a positive ***,avoiding M/A islands distributed in the chain along the rolling direction on the matrix hindered the possibility of voids coalescing into cracks and stabilized the flanging performance.

关键词： Multiphase steel Flangeability Martensite/austenite island-Microstructural homogeneity-Microstructure Compact strip production process

Regulating the non-effective carriers transport for high-performance lithium metal batteries

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Journal of Energy Chemistry 2024年第5期92卷 132-141页

作者： Simeng Wang Youchun Yu Shaotong Fu Hongtao Li Jiajia Huang institute of Process engineering Chinese Academy of SciencesBeijing 100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing 100049China Haike group research institute of Innovation&technology Dongying 257000ShangdongChina

The absence of control over carriers transport during electrochemical cycling,accompanied by the deterioration of the solid electrolyte interphase(SEI)and the growth of lithium dendrites,has hindered the development of lithium metal ***,a separator complexion consisting of polyacrylonitrile(PAN)nanofiber and MIL-101(Cr)particles prepared by electrospinning is proposed to bind the anions from the electrolyte utilizing abundant effective open metal sites in the MIL-101(Cr)particles to modulate the transport of non-effective *** binding effect of the PANM separator promotes uniform lithium metal deposition and enhances the stability of the SEI layer and long cycling stability of ultra-high nickel layered oxide *** PANM as the Li||NCM96 separator enables high-voltage cycling stability,maintaining 72%capacity retention after 800 cycles at a charging and discharging rate of 0.2 C at a cut-off voltage of 4.5 V and 0°***,the excellent high-rate performance delivers a specific capacity of 156.3 mA h g^(-1) at 10 *** addition,outstanding cycling performance is realized from−20 to 60°*** separator engineering facilitates the electrochemical performance of lithium metal batteries and enlightens a facile and promising strategy to develop fast charge/discharge over a wide range of temperatures.

关键词： Functional separators Metal-organic frameworks 3D continuous ion transport networks Electrospinning Lithium metal batteries

Performance Enhancement of Parabolic Trough Collector by Using Homogenizer and Spiral

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Journal of Thermal Science 2024年第2期33卷 658-674页

作者： LI Peijing LIU Taixiu QIN Yuanlong ZHENG Zhimei ZHAO Kai LIU Qibin School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China institute of engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Science Beijing100049China Department of Thermal Science and Energy engineering University of Science and Technology of ChinaHefei230027China research institute of Science and technology of china Three Gorges group Corporation Beijing100038China

In conventional parabolic trough collectors(PTCs),sunlight is concentrated at the bottom of the absorber tube,resulting in a significant circumferential temperature gradient across the absorber tube,heat loss and thermal deformation,which affects the safety and thermal performance of *** this study,a new receiver with homogenizer and spiral(RHS) is proposed,achieving the optical and thermal synergy to ameliorate the thermal deformation of the absorber tube and enhance thermal efficiency.A plane structure homogenizer is designed to improve uniformity of the concentrated solar flux of absorber tube through second *** combination with the spiral,it improves the optical-thermal efficiency of the PTC by enhancing heat exchange between the fluid and the backlight side of the absorber *** performance of the collector is numerically studied by building a three-dimensional coupled light-thermal-structure *** results show that the thermal deformation of the RHS is reduced by more than 96% and the optical-thermal efficiency is improved by 1.2%-0.63% compared with conventional receivers(CRs) under the same inlet temperature *** proposed receiver is validated to be effective in reducing thermal deformation and improving optical-thermal efficiency.

关键词： parabolic trough collector homogenizer thermal deformation spiral

Exploring mechanism of hidden,steep obliquely inclined bedding landslides using a 3DEC model:A case study of the Shanyang landslide in Shaanxi Province,china

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china Geology 2024年第2期7卷 303-314,I0001-I0003页

作者： Jia-yun Wang Zi-long Wu Xiao-ya Shi Long-wei Yang Rui-ping Liu Na Lu Xi’an Center of china Geological Survey/Northwest china Center for Geoscience Innovation Xi’an 710119China Xi’an University of Science and technology Xi’an 710054China Wuhan Design&research institute Co. Ltd.of China Coal Technology&Engineering GroupWuhan 430064China

Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily *** phenomenon has become a focal point in landslide ***,there is a lack of studies on the failure modes and mechanisms of hidden,steep obliquely inclined bedding *** study investigated the Shanyang landslide in Shaanxi Province,*** field investigations,laboratory tests of geotechnical parameters,and the 3DEC software,this study developed a numerical model of the landslide to analyze the failure process of such *** findings indicate that the Shanyang landslide primarily crept along a weak interlayer under the action of *** landslide,initially following a dip angle with the support of a stable inclined rock mass,shifted direction under the influence of argillization in the weak interlayer,moving towards the apparent dip *** slide resistance effect of the karstic dissolution zone was increasingly significant during this process,with lateral friction being the primary resistance force.A reduction in the lateral friction due to karstic dissolution made the apparent dip sliding characteristics of the Shanyang landslide more ***,deformations such as bending and uplift at the slope’s foot suggest that the main slide resistance shifts from lateral friction within the karstic dissolution zone to the slope foot’s resistance force,leading to the eventual buckling failure of the *** study unveils a novel failure mode of apparent dip creep-buckling in the Shanyang landslide,highlighting the critical role of lateral friction from the karstic dissolution zone in its failure *** insights offer a valuable reference for mitigating risks and preventing disasters related to obliquely inclined bedding landslides.

关键词： Landslide Steep obliquely inclined bedding slope Failure mode Failure mechanism Apparent dip creep-buckling Lateral friction 3DEC model Landslide numerical model Geological hazards survey engineering

A Novel Anti-Collision Algorithm for Large Scale of UHF RFID Tags Access Systems

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Computers, Materials & Continua 2024年第7期80卷 897-912页

作者： Xu Zhang Yi He Haiwen Yi Yulu Zhang Yuan Li Shuai Ma Gui Li Zhiyuan Zhao Yue Liu Junyang Liu Guangjun Wen Jian Li School of Information and Communication engineering/Yibin institute University of Electronic Science and Technology of ChinaChengdu611731China Department of IoT technology research China Mobile Research InstituteBeijing100053China The 10th research institute of china Electronics technology group Corporation Chengdu611731China College of Information and Communication National University of Defense TechnologyWuhan430019China

When the radio frequency identification(RFID)system inventories multiple tags,the recognition rate will be seriously affected due to *** on the existing dynamic frame slotted Aloha(DFSA)algorithm,a sub-frame observation and cyclic redundancy check(CRC)grouping combined dynamic framed slotted Aloha(SUBF-CGDFSA)algorithm is *** algorithm combines the precise estimation method of the quantity of large-scale tags,the large-scale tags grouping mechanism based on CRC pseudo-randomcharacteristics,and the Aloha anti-collision optimization mechanism based on sub-frame *** grouping tags and sequentially identifying themwithin subframes,it accurately estimates the number of remaining tags and optimizes frame length accordingly to improve efficiency in large-scale RFID *** outcomes demonstrate that this proposed algorithmcan effectively break through the system throughput bottleneck of 36.8%,which is up to 30%higher than the existing DFSA standard scheme,and has more significant advantages,which is suitable for application in largescale RFID tags scenarios.

关键词： Radio frequency identification anti-collision tags grouping dynamic framed slotted Aloha

Experimental investigation of spectral evolution in flash radiation by hypervelocity impact on aluminum plates

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Defence technology（防务技术） 2024年第7期37卷 96-110页

作者： Xing Chen Yonggang Lu Zhiwen Li Zhonghua Cui institute of Systems engineering China Academy of Engineering PhysicsMianyang 621900SichuanChina Chongqing Qianwei technology group Co. LtdChongqing 401121China

In this study,a series of hypervelocity impact tests were carried out based on a two-stage light gas gun,and the sequence spectrum and radiation evolution data of the impact products under different impact conditions were *** diameter of the projectile is 3-5 mm,the impact velocity is 3.13-6.58 km/s,and the chamber pressure is 0.56-990 *** spectrum of ejected debris cloud in the 250-310 nm band were obtained using a transient spectral measurement system and a multi-channel radiometer measurement *** test results reveal that the flash radiation intensity increases as a power function with the kinetic energy of the ***,the peak value of the line spectrum decreases as the chamber vacuum degree increases,while the radiation width gradually *** line spectrum in the spectral characterization curve corresponds to the ejected debris clouds splitting phase,which does not produce significant line spectrum during material fragmentation and is dominated by the continuum spectrum produced by blackbody *** will appear one or three characteristic peaks in the flash radiation time curve,the first and second peaks correspond to the penetration phase and the third peak corresponds to the expansion phase of the ejected debris clouds on the time scale,the first and second peaks are more sensitive to the chamber vacuum degree,and when the pressure is higher than 99 Pa,the first and second characteristic peaks will *** radiant heat attenuation of the flash under different impact conditions is significantly different,the attenuation exponent has a power function relationship with the impact velocity and the chamber vacuum degree,while the attenuation exponent has a linear relationship with the diameter of the projectile,the specific expression of the attenuation exponent is obtained by *** findings from this research can serve as a valuable reference for remote diagnostic technologies based on flash radiation characte

关键词： Hypervelocity impact Flash radiation Evolution Spectral characteristics Damage evaluation

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

Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

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Chinese Journal of Chemical engineering 2024年第1期65卷 1-7页

作者： Risheng Shen Shilong Li Yuqing Sun Yuan Bai Jian Lu Wenheng Jing State Key Laboratory of Materials-Oriented Chemical engineering Nanjing Tech UniversityNanjing 210009China National Energy group Science and technology research institute Co. Ltd.Nanjing 210023China

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide(H_(2)O_(2)).But due to the oxidation degradation of the organic membranes(***)by the strong oxidative radicals(e.g.OH)generated via the activation of H_(2)O_(2)by iron ions(Fe^(3+)),the short effective lifetime of membranes remains a *** nano tin oxide(SnO_(2))has great potential for the removal of Fe^(3+)in strongly oxidative H_(2)O_(2)because of its ability to stabilize H2O_(2)and preferentially adsorb Fe^(3+).Herein,we have designed for the first time a flower-like robust SnO_(2)membrane on the ceramic support by in situ template-free one-step hydrothermal *** three-dimensional loose pore structure in the membrane built by interlacing SnO_(2)nanosheets endows the SnO_(2)membrane with a high specific surface area and abundant adsorption sites(AOH).Based on the coordination complexation and electrostatic attraction between the SnO_(2)surface and Fe^(3+),the membrane shows a high Fe3+removal efficiency(83%)and permeability(24 L·m^(-2)·h^(-1)·MPa^(-1))in H_(2)O_(2).This study provides an innovative and simple approach to designing robust SnO_(2)membranes for highly efficient removal of Fe^(3+)in harsh environments,such as strong oxidation conditions.

关键词： Hydrogen peroxide SnO_(2)membrane Adsorption Hydrothermal