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Journal of Energy Chemistry 2024年第7期94卷 70-77页

作者： Haowen Cui yan-Xia Chen Hefei National Research Center for Physical Sciences at Microscale and Department of Chemical Physics University of Science and Technology of ChinaHefei 230026AnhuiChina

Despite substantial efforts in developing high-performance catalysts for the oxygen reduction reaction(ORR),the persistent challenge lies in the high onset overpotential of the ORR,and the effect of the elec-trolyte solution cannot be ***,we have systematically investigated the impact of adsorbate species and concentration,as well as solution pH,on the ORR activity on Pt(111)and Pt(poly)*** results all tend to establish a linear quantitative relationship between the onset potential for ORR and the adsorption equilibrium potential of the *** finding indicates the decisive role of adsorbates in the onset potential for ORR,suggesting that the adsorption potential of adsorbates can serve as an intuitive criterion for ORR *** support for this conclusion is derived from experimental results obtained from the oxygen evolution reaction on Pt(poly)with different adsorbate species and from the hydrogen evolution reaction on Pt(111)with iodine *** further propose both an empirical equation for the onset potential for ORR and the concept of a potential-regulated adsor-bate shielding effect to elucidate the influence of adsorbates on ORR *** study provides new insights into the high onset overpotential of the ORR and offers potential strategies for predicting and enhancingORRactivity inthefuture.

关键词： Oxygen reduction reaction Activity Adsorbate Equilibrium potential Pt(111)

Synthesis and characteristics of transparent Gd_(2)O_(3)ceramics with cubic structure

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Journal of Advanced Ceramics 2024年第4期13卷 463-468页

作者： Akio Ikesue yan Lin Aung World Lab Co. Nagoya456-8587Japan

Transparent Gd_(2)O_(3)ceramics with a cubic crystal structure were successfully synthesized for the first *** Gd_(2)O_(3)ceramics subjected to hot isostatic press(HIP)at 1070℃consisted of uniform grains of 2-3μm,and only a few residual pores could be detected inside the materials.X-ray diffraction(XRD)shows that the obtained polycrystalline materials have a cubic crystal structure,and the transmission polarized light observation shows that there is no birefringence inside the materials,indicating inherent optical properties of the cubic crystal *** optical absorption edge is 640 nm(optical band gap:2.1 eV),and the transmittance in the visible to near-infrared region is 72%,which is close to the theoretical transmittance calculated from Fresnel *** constant of this material is almost wavelength-independent,and it is diamagnetic since it has the opposite polarity to that of common paramagnetic materials.

关键词： gadolinium oxide cubic hot isostatic press(HiP) diamagnetic Verdet constant

Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

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Defence Technology（防务技术） 2024年第3期33卷 186-196页

作者： Yujie yan Bo Jin Rufang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center *** carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature *** was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the *** investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal *** carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 *** to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

关键词： g-C_(3)N_(4) Chitosan Co Ammonium perchlorate Pyrolysis kinetics

A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

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Journal of Materials Science & Technology 2024年第5期172卷 202-212页

作者： Fei Huang Jiyong Hu Xiong yan Shanghai Frontier Science Research Center for Modern Textiles Donghua UniversityShanghai 201620China

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide ***,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body ***,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain *** proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite *** strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the ***,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural *** final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,*** sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

关键词： Double-threaded yarn Strain redistribution Hysteresis Human motion monitoring

Microscale spherical TiO_(2)powder prepared by hydrolysis of TiCl_(4)solution:Synthesis and kinetics

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Particuology 2024年第1期84卷 60-71页

作者： Peiyi yan Ying Zhang Shili Zheng School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Panzhihua617000China

Hydrolysis of TiCl_(4)solution is capable of preparing microscale TiO_(2)*** research studied the synthesis of microscale spherical TiO_(2)powders and the hydrolysis *** effects of the flow field generated by different agitators and baffles in the crystallizer,the initial free acid concentration,the initial equivalent TiO_(2)concentration,and the temperature on the hydrolysis progress and powder morphology were systematically *** results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders,and the axial flow can improve the sphericity of the *** increased free HCl and equivalent TiO_(2)concentrations in the pregnant solution inhibit the forward hydrolysis reaction,prolong the time to reach equilibrium,and reduce the *** appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and *** with sizes ranging from around 5 um-40μm can be tuned under controlled flow field,solution compositions,and temperature *** addition,the Cheng and Wunderlich modified Avrami equation was used for the crystallization kinetic *** effects of the free HCl concentration,equivalent TiO_(2)concentration,and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction *** the free HCl and equivalent TiO_(2)concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei,thus increasing the final powder size,while increasing the temperature will lead to the opposite results.

关键词： TiCl_(4) Hydrolysis Microscale TiO_(2) Spherical Kinetics

Particles attrition of binary mixtures in the coal-fueled chemical looping system based on fluidized bed

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Particuology 2024年第3期86卷 281-290页

作者： Heyu Li Zhe Sun yan Cao Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Bejing 100049China CAS Key Laboratory of Renewable Energy Guangzhou 510640China Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640China College of Chemistry and Chemical Engineering Anhui UniversityHefei230601China

In this work,a reactive air jet attrition device with auto-recording and collection of elutriated fines was *** established insights into the physiochemical interaction and further correlated attrition behaviors between char and oxygen carriers under various operation *** attrition rate increased by over 110% upon the introduced CO_(2),which brought in the significant effect of thermo-chemical stress,similarly in effects of the increased char addition ratio and the decreased sizes of char or hematite in different *** the char-hematite co-attrition process,the elutriated carbon loss of char with poor mechanical strength was found to be over 10%,while the reactive iron loss of hematite was found to be 6.3%,and was enriched in elutriated *** reaction-derived thermochemical stress and the collision-derived mechanical stress jointly controls the particle attrition during the cyclic transformation of oxygen carrier particles in coal-fueled chemical looping fluidization,especially sig-nificant in its reduction stage.

关键词： Attrition Binary species Chemical looping Oxygen carrier CO_(2)capture

Effect of dissolved-oxygen on the flotation behavior of pyrite at high altitude area

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2148-2158页

作者： yan Miao Guangke Ye Guofan Zhang School of Minerals Processing and Bio-engineering Central South UniversityChangsha 410083China

With the continuous development of mineral resources to high altitude areas,the study of sulfide ore flotation in unconventional systems has been *** is a consensus that moderate oxidation of sulfide ore is beneficial to flotation,but the specific suitable dissolved oxygen value is inconclusive,and there are few studies on sulfide ore flotation under low dissolved oxygen environment at high *** this paper,we designed and assembled an atmosphere simulation flotation equipment to simulate the flotation of pyrite at high altitude by controlling the partial pressure of N_(2)/O_(2) and dissolved oxygen under atmospheric conditions.X-ray photoelectron spec-troscopy(XPS),atomic force microscope(AFM),Fourier transform infrared spectrometer(FT-IR),UV-vis spectrophotometer,zeta po-tential,and contact angle measurements were used to reveal the effects of surface oxidation and agent adsorption on pyrite at high altitude(4600 m dissolved oxygen(DO)=4.0 mg/L).The results of pure mineral flotation indicated that the high altitude and low dissolved oxy-gen environment is favorable for pyrite *** angle measurements and XPS analysis showed that the high altitude atmosphere nslows down the oxidation of pyrite surface,facilitates S_(n)^(2-)/S^(0) production and enhances surface *** calcula-tions and zeta potential analysis showed that the influence of atmosphere on the form of pyrite adsorption is small,and the different atmo-spheric conditions are consistent with dixanthogen electrochemical adsorption,with lower Zeta potential under high altitude atmosphere and significant potential shift after sodium isobutyl xanthate(SIBX)*** results of FT-IR,UV-vis,and AFM analysis showed that SIBX adsorbed more on the surface of pyrite under high altitude atmosphere and adsorbed on the surface in a mesh structure com-posed of column/*** results of the experimental study revealed the reasons for the easy flotation of sul

关键词： high altitude dissolved-oxygen pyrite flotation oxidation

Fast measurement and prediction method for electromagnetic susceptibility of receiver

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Journal of Systems Engineering and Electronics 2024年第2期35卷 275-285页

作者： CHEN yan LU Zhonghao LIU Yunxia State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and TechnologyNational University of Defense TechnologyChangsha 410073China State Key Laboratory of Astronautic Dynamics Xi’an 710043China

Aiming at evaluating and predicting rapidly and accurately a high sensitivity receiver’s adaptability in complex electromagnetic environments,a novel testing and prediction method based on dual-channel multi-frequency is proposed to improve the traditional two-tone ***,two signal generators are used to generate signals at the radio frequency(RF)by frequency scanning,and then a rapid measurement at the intermediate frequency(IF)output port is carried out to obtain a huge amount of sample data for the subsequent ***,the IF output response data are modeled and analyzed to construct the linear and nonlinear response constraint equations in the frequency domain and prediction models in the power domain,which provide the theoretical criteria for interpreting and predicting electromagnetic susceptibility(EMS)of the *** experiment performed on a radar receiver confirms the reliability of the method proposed in this *** shows that the interference of each harmonic frequency and each order to the receiver can be identified and predicted with the sensitivity *** on this,fast and comprehensive evaluation and prediction of the receiver’s EMS in complex environment can be efficiently realized.

关键词： electromagnetic susceptibility(EMS) receiver dualchannel multi-frequency nonlinear response frequency domain power domain

CFD-DEM study of impacts of the porous distributor medium on fluidization characteristics of a 2D-fluidized bed

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Particuology 2024年第4期87卷 54-73页

作者： Fei Wang Yishan Zeng Hao yan School of Mechanical Engineering Hefei University of TechnologyHefei230009China

Gas-solid bubbling fluidized beds are widely used in chemical,energy,construction,and other industrial fields due to their excellent fluidization performance.2D-fluidized beds with planar rectangular columns of finite thickness are widely used in fluidized bed studies,and it is essential for understanding the hydrodynamics of gas-particle ***,the distributor(porous medium)at the bottom of the bed has a crucial influence on the fluidization performance of the 2D-fluidized *** this work,the fluidization mechanism and gas-solid dynamic characteristics of the fluidized bed under three porous media are studied by CFD-DEM coupled with the porous medium model,and the accuracy of numerical simulation is verified by a high-speed photography *** show that with the increase in the flow resistance of the porous medium,the average and standard deviation of the bubble diameter decrease,and the time and position of particles in the dead zone to participate in the core-annular flow *** a low fluidization velocity,the dead zone in the bed can be considerably reduced by increasing the flow resistance.

关键词： Fluidized bed CFD-DEM Porous medium Bubble dynamics Solid mixing

Safety analysis of temporary anchorage system for immersed tube in Shenzhen-Zhongshan Link

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 797-813页

作者： Lei yan Jinning yan Guoping Xu Shuanhai He Zechen Zhang School of Highway Chang'an University Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology Chang'an University CCCC Highway Consultants Co.Ltd.

In the construction of the Shenzhen-Zhongshan Link, a temporary anchorage system,distributed uniformly along the pipe wall, has been employed. To assess the safety and reliability of this system, a combined method utilizing numerical analysis and model experiments was applied to study the safety of the temporary anchorage system and the reliability of the tension rods. Firstly, an overall model of the caisson segment based on GINA rebound force was established to analyze the stress state of the entire system. Secondly, a comprehensive numerical analysis and model experiment verification were conducted for the single tensioning system, revealing its failure mode and safety margin. The results indicate that the tension rod systems are uniformly stressed at an average of 444 k N during underwater jointing, with a safety factor of 1.94. At this point, the maximum von Mises stresses appearing at the front plate corners and the lower edge of the U-groove, with stress values of 181.8 MPa and 172.4 MPa, and safety factors of 1.54 and 1.71, *** the tension rod force reaches 940 k N, the tensioning system reaches its bearing limit,with initial yielding occurring at the front plate corners. Model experiments were conducted to verify the theoretical analysis results, under a test load of 444 k N, the stresses at the front plate corners and the lower edge of the U-groove were 159.6 and 195.9 MPa,respectively. As the test load increased to 940 k N, these stresses reached 390 and 389 MPa,exhibiting good agreement with the numerical analysis. Considering the uncertainty of loads and materials, a reliability analysis of the tension rods was conducted, yielding a reliability index of 4.34, meeting the secondary safety standard. Based on the comprehensive analysis, it can be concluded that the temporary anchorage system in the caisson segments of the Shenzhen-Zhongshan Link exhibits excellent safety margins.

关键词： Tunnel engineering Immersed tube structure Anchorage system Full-scale model test Load bearing performance Safety assessment.