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Potential applications for composite utilization of rubber and plastic in asphalt pavements:A critical review

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Journal of Traffic and Transportation engineering(English Edition) 2024年第05期 939-971页

作者： Haibin Li Lichang Zhou Yuhang Cai Yongfei Zhang Bature Auwal Ibrahim Zixuan Feng Liyun Tang Zhigang Li Fayong Yang school of Civil and architectural engineering Xi'an University of Science and Technology Road engineering Research Center Xi'an University of Science and Technology school of Highway Chang'an University Xi'an Highway Research Institute Co. Ltd.

Waste plastics and rubber have always posed a threat to the environment and a great challenge for disposal. The use of these two waste materials as modifiers for road asphalt provides new road asphalt binders and at the same time provides a new way for waste material resource treatment. Rubber-modified asphalt and plastic-modified asphalt have received widespread attention due to their green and low-carbon characteristics and some performance advantages, but there are still some performance shortcomings that hinder their promotion and application. In order to continue to explore the application of waste materials in the field of road engineering, combined with the performance advantages of both, many scholars began to study the rubber-plastic composite modified asphalt(RPCMA). Therefore, this paper reviewed the different types of waste rubber and plastic, the comprehensive performance of different types of asphalt and its mixture performance,analyzed the modification mechanism of rubber-plastic composite modified asphalt and its performance changes. The results show that rubber-plastic composite modified asphalt is mostly prepared by directly adding modified materials. However, the pretreatment or melt granulation of rubber and plastic will make the performance of rubber-plastic modified asphalt has improved. There is a mutual promotion mechanism between rubber and plastic in asphalt, which makes the performance of rubber-plastic modified asphalt better than that of asphalt obtained by a single modification method(rubber modified asphalt or plastic modified asphalt). In some properties, it can be close to the commercial SBS modified asphalt. The performance of rubber and plastic composite modified asphalt at high temperature has been generally recognized by researchers, but its low-temperature performance is still controversial. Therefore, it is recommended to apply in high-temperature areas. Future work should focus on the development of composite modifiers with st

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Pipeline thickness estimation using the dispersion of higher-order SH guided waves

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Chinese Physics B 2024年第7期33卷 389-396页

作者：代政辰刘金霞龙云飞张建海 Tribikram Kundu 崔志文 Department of Acoustics and Microwave Physics College of PhysicsJilin UniversityChangchun 130012China school of Mechanical and Aerospace engineering Jilin UniversityChangchun 130025China Department of Civil and architectural engineering and Mechanics University of ArizonaTucsonArizona 85721USA College of Aerospace and Mechanical engineering University of ArizonaTucsonAZ 85721USA State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.

关键词： pipeline wall thickness higher-order modes SH guided waves dispersion

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Macro electrochemical milling and its hybrid variants

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Chinese Journal of Aeronautics 2024年第8期37卷 1-35页

作者： Ningsong QU Xiaolong FANG Junzhong ZHANG Huanghai KONG Yang LIU Minglu WANG Xiaokang YUE Yuehong MA Zhihao SHEN Jiajie CHEN College of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China school of Mechanical engineering Jiangsu UniversityZhenjiang 212003China school of Mechanical engineering Jiangsu University of Science and TechnologyZhenjiang 212003China school of Mechanical engineering Hefei University of TechnologyHefei 230009China

Macro electromechanical milling has recently attracted increasing attention because numerous large thin-walled structures composed of difficult-to-cut materials are employed in the aerospace *** paper reviews recent developments in state-of-the-art macro electromechanical *** fundamental aspects of material removal mechanisms,such as the generation and breakdown behaviors of passive oxide films of typical difficult-to-cut materials,were *** methods for breaking down passive films are summarized,and simulation methods for the machining process coupling multiple physical fields are *** electrochemical milling methods,including fly mode electrochemical milling and sink electrochemical milling,are *** made to improve process performance,such as the material removal rate,surface quality,and machining accuracy,are *** addition,the main hybrid electrochemical milling methods,including electrochemical discharge milling,mechano-electrochemical milling,and electrochemical mill grinding,are also presented.

关键词： Electrochemical machining Electrochemical milling Material removal rate Surface quality Electrochemical discharge milling Electrochemical millgrinding

Leaching behavior and microstructure of phosphorus in converter slag

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Journal of Iron and Steel Research International 2024年第7期31卷 1646-1660页

作者： Chao-gang Zhou Jin-yue Li Qing-gong Chen Yin-ye Yang Wei Gong Li-qun Ai Shu-huan Wang Bei-yue Ma College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina College of Materials Science and engineering Guizhou Minzu UniversityGuiyang 550025GuizhouChina school of Materials and architectural engineering Guizhou Normal UniversityGuiyang 550025GuizhouChina school of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

Converter slag is a by-product of the steelmaking process and contains a large amount of Ca,Fe,P and other *** the phosphorus in the converter slag can be effectively extracted,the resulting phosphorus can be used as a phosphate *** in converter slag is mainly enriched in 2CaO·SiO_(2)-3CaO·P_(2)O_(5)(C_(2)S-C_(3)P)solid solution and is easily dissolved in ***,acid leaching method was used to dissolve the solid solution to extract phosphorus in converter slag,so as to realize the recycling of phosphorus resources in converter *** leaching behavior of three actual converter slags from different steel mills in acid leaching solutions composed of citric acid,sodium hydroxide,hydrochloric acid and deionized water was studied by X-ray diffraction,scanning electron microscopy combined with energy dispersive spectrometry,Fourier transform infrared spectroscopy and Raman spectroscopy to reveal the change in object image structure as well as SiO_(4) and PO_(4) tetrahedron before and after acid *** results show that only a small amount of phosphorus in converter slag with too low basicity is enriched in C_(2)S-C_(3)P solid solution,resulting in poor leaching *** the converter slag has a high basicity,the removal effect of phosphorus is 70.64%-81.88%.In addition,when the basicity of converter slag is roughly the same,the dephosphorization effect of slag with high FeO content is relatively *** acid leaching will cause depolymerization behavior of SiO_(4) and PO_(4) tetrahedron,so that the mole fraction of Q0(Si)(asymmetric stretching vibration of Si-O bond in SiO_(4) tetrahedron with bridge oxygen number of 0)and NBO/Si(non-bridging oxygen in silicate tetrahedra)will ***-containing solids can be obtained from the solution after acid leaching through static precipitation,and the solids have the potential to make phosphate fertilizers.

关键词： Dephosphorization converter slag Acid leaching Phosphorus Solid solution Slag structure

Ultrathin polyimide-based composites with efficient low-reflectivity electromagnetic shielding and infrared stealth performance

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Nano Research 2024年第7期17卷 6700-6712页

作者： Xu Zhao Xinwei Tang Yunlong Qiao Shuangshuang Li Zihang Zhang Yezi Lu Mingyang Zhu Zaiyin Hu Lijuan Long Zicheng Wang Tianxi Liu The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringInternational Joint Research Laboratory for Nano Energy CompositesJiangnan UniversityWuxi 214122China Guizhou Aerospace Wujiang Electro-mechanical Equipment Co. Ltd.No.20-5Dalian Road Aerospace Industrial ParkHuichuan DistrictZunyi 563000China school of Materials and architectural engineering Guizhou Normal UniversityGuiyang 550025China

Researching and manufacturing materials that possess both electromagnetic interference(EMI)shielding and infrared stealth capabilities is of great ***,an ultrathin polyimide-based nonwoven fabric with low-reflection EMI shielding/infrared stealth performance is successfully fabricated by in-situ loading of Fe_(3)O_(4)/Ag nanoparticles on the surface of polyimide(PI)fiber(PFA),and followed by bonding with a commercial Cu/Ni *** synergistic assembly of PFA and Cu/Ni promotes the rational construction of hierarchical impedance matching,inducing electromagnetic waves(EMW)to enter the composite and be dissipated as much as ***,the existence of Cu/Ni mesh on back of PFA facilitates the formation of electromagnetic resonance and destructive interference of EMW reflected from composite,leading to a lowerreflectivity(0.26)EMI shielding performance of 58 dB within 24–40 GHz at a thinner thickness(430μm).More importantly,the fluffy PFA nonwoven fabric and metal Cu/Ni mesh endow composite with good thermal insulation and low infrared emissivity,resulting in excellent infrared stealth performance in various *** a result,such excellent compatibility makes it possible to become a promising defense material to be applied in military tent for preventing electromagnetic and infrared radiation.

关键词： polyimide electromagnetic interference shielding low reflection infrared stealth

Teaching Design of Course Building Decoration Materials Based on Generative Artificial Intelligence

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Journal of Landscape Research 2024年第3期16卷 83-87页

作者： LIU Yanan HONG Xiaochun QIAN Liang school of architectural engineering Yangzhou Polytechnic InstituteYangzhouJiangsu 225127China College of architectural Science and engineering Yangzhou UniversityYangzhouJiangsu 225127China

With the digital transformation of global education and China's emphasis on education digital,generative AI technology has been widely used in the field of higher *** this paper,the development of generative AI technology and its potential in personalized learning,interactive content creation and adaptive assessment in education were introduced ***,the application case of generative AI tools in teaching content creation,scenario-based teaching content development,visual teaching content development,complex concept deconstruction and analogy,student-led application practice and other aspects in the teaching of Building Decoration Materials was *** the teaching experiment and effect evaluation,the positive influence of generative AI technology on the improvement of students'learning effect and teaching efficiency was ***,some thoughts and inspirations on the combination of educational theory and generative AI technology,the integration of teaching design and generative AI technology,and the practice cases and effect evaluation were put forward,and the importance of teacher role transformation and personalized learning path design was emphasized to provide theoretical and practical support for the innovative development of higher education.

关键词： Generative artificial intelligence Higher education Teaching design Education digitization

Disc-cutter induced rock breakage mechanism for TBM excavation in rock masses with different joint shear strengths

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Underground Space 2024年第6期19卷 119-137页

作者： Bolong Liu Bo Li Liang Zhang Rui Huang Huicai Gao Shilin Luo Tao Wang Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing UniversityShaoxing 312000China College of Civil engineering Tongji UniversityShanghai 200092China College of Civil and architectural engineering Xi’an University of Science and TechnologyXi’an 710054China College of Civil engineering Changsha UniversityChangsha 410022China school of Transportation Science and engineering Harbin Institute of TechnologyHarbin 150040China Chongqing Research Institute of Harbin Institute of Technology Harbin Institute of TechnologyChongqing 401151China

When tunnel boring machines(TBMs)excavate through jointed rock masses,the cutting efficiency is strongly affected by the shear strength of joints,the mechanism of which,however,remains poorly *** this study,a series of disc-cutter indentation tests were conducted on granite rock mass specimens with different joint shear *** the indentation,the cracking process was recorded by a digital image correlation(DIC)*** deformation and strength of specimens,cracking behavior,rock breakage mode and cutting efficiency were quantitatively *** addition,to investigate the combined effects of joint shear strength,orientation and spacing on the rock breakage mechanism,numerical rock mass models were established based on a particle flow code *** results reveal that the cracking of primary and secondary cracks changes from the mixed shear-tensile to tensile mode in the initial stage,while the joint shear strength does not affect the cracking mode in the subsequent propagation *** rock breakage mode is classified to an internal block breakage mode,a cross-joint breakage mode and a cutters-dependent breakage *** cross-joint breakage mode is optimal for improving the cutting *** simulation results reveal that the increase in the joint shear strength changes the internal block breakage mode to cross-joint breakage mode for rock masses of particular ranges of joint orientation and *** findings provide basis for improving the TBM cutting efficiency through jointed rock masses.

关键词： Indentation test Joint shear strength Disc cutter Rock breakage mechanism Cutting efficiency

Ligand modulation of active center to promote lead-free Cs_(2)AgInCl_(6)photocatalytic CO_(2)reduction

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Journal of Energy Chemistry 2024年第8期95卷 660-669,I0015页

作者： Baofei Sun Wei Chen Yanyi Huang Daofu Wu Heng Luo Faguang Kuang Hongmei Ran Yichen Liu Liqin Gao Jinchen Zhou Bo Gao Qiang Huang Xiaosheng Tang Key Laboratory of Human Brain Bank for Functions and Diseases of Department of Education of Guizhou Province College of Basic MedicalGuizhou Medical UniversityGuiyang 550025GuizhouChina school of electromechanical and Automotive engineering Yantai UniversityYantai 264005ShandongChina State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina College of Optoelectronic engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China school of Materials Science and engineering Zhengzhou UniversityZhengzhou 450001HenanChina

Metal halide perovskites(MHP)are potential candidates for the photocatalytic reduction of CO_(2)due to their long photogenerated carrier lifetime and charge diffusion ***,the conventional long-chain ligand impedes the adsorption and activation of CO_(2)molecules in practical ***,a ligand modulation technology is employed to enhance the photocatalytic CO_(2)reduction activity of lead-free Cs_(2)AgInCl_(6)microcrystals(MCs).The Cs_(2)AgInCl_(6)MCs passivated by Oleic acid(OLA)and Octanoic acid(OCA)are used for photocatalytic CO_(2)*** results show that the surface defects and electronic properties of Cs_(2)AgInCl_(6)MCs can be adjusted through ligand *** with the OLA-Cs_(2)AgInCl_(6),the OCA-Cs_(2)AgInCl_(6)catalyst demonstrated a significant improvement in the catalytic yield of CO and CH_(4).The CO and CH_(4)catalytic yields of OCA-Cs_(2)AgInCl_(6)reached 171.88 and34.15μmol g^(-1)h^(-1)which were 2.03 and 12.98 times higher than those of OLA-Cs_(2)AgInCl_(6),and the total electron consumption rate of OCA-Cs_(2)AgInCl_(6)was 615.2μmol g^(-1)h^(-1)which was 3.25 times higher than that of OLA-Cs_(2)AgInCl_(6).Furthermore,in situ diffuse reflectance infrared Fourier transform spectra revealed the enhancement of photocatalytic activity in Cs_(2)AgInCl_(6)MCs induced by ligand *** study illustrates the potential of lead-free Cs_(2)AgInCl_(6)MCs for efficient photocatalytic CO_(2)reduction and provides a ligand modulation strategy for the active promotion of MHP photocatalysts.

关键词： Surface ligand Photocatalysis CO_(2)reduction Lead-free perovskite Reactive mechanism

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A Coordinate-Free Approach to the Design of Generalized Griffis-Duffy Platforms

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Chinese Journal of Mechanical engineering 2024年第3期37卷 95-103页

作者： Chengwei Shen Xu Pei Lubin Hang Jingjun Yu College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityHangzhou 311300China school of Mechanical engineering and Automation Beihang UniversityBeijing 100191China school of Mechanical and Automotive engineering Shanghai University of Engineering ScienceShanghai 201620China

architectural singularity belongs to the Type II singularity,in which a parallel manipulator(PM)gains one or more degrees of freedom and becomes *** remaining permanently in a singularity are beneficial for linearto-rotary motion ***-Duffy(GD)platform is a mobile structure admitting a Bricard *** this paper,we present a coordinate-free approach to the design of generalized GD platforms,which consists in determining the shape and attachment of both the moving platform and the fixed *** generalized GD platform is treated as a combination of six coaxial single-loop mechanisms under the same *** to the inversion,hidden in the geometric structure of these single-loop mechanisms,the mapping from a line to a circle establishes the geometric transformation between the fixed base and the moving platform based on the center of inversion,and describes the shape and attachment of the generalized GD ***,the center of inversion not only identifies the location of rotation axis,but also affects the shape of the platform mechanism.A graphical construction of generalized GD platforms using inversion,proposed in the paper,provides geometrically feasible solutions of the manipulator design for the requirement of the location of rotation axis.

关键词： Generalized Griffis-Duffy platforms Self-motion Inversion Coordinate-free determination Manipulator design

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