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Establishment of a three-dimensional particle library for graded crushed stone based on a new aggregate morphology characterization method

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 117-130页

作者： Haitao Ge Aimin sha Zhenqiang Han School of Future Transportation Chang'an UniversityXi'an 710064China University of Strasbourg INSA StrasbourgCNRSICubeUMR 7357Strasbourg F-67000France School of Highway Chang'an UniversityXi'an 710064China Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an UniversityXi'an 710064China

The morphology of graded crushed stone(GCS)particles has an essential influence on the performance of aggregate *** impact of particle shape is a comprehensive effect that cannot be considered separately,leading to difficulties in establishing the relationship between the mixture properties and the aggregate morphology by using laboratory *** discrete element method(DEM)is an effective way widely adopted to reconstruct the morphology of particles and simulate performance tests of granular ***,selecting limited particles characterizing a real particle-assembly for simulation is still a challenge in current research due to the inherent rich variability of particle *** this study,based on the acquisition of three-dimensional(3D)aggregate shapes by using laser scanning,ellipsoid index(EDI)translating the particle shape as a function of surface area,volume,and contour length is proposed to comprehensively evaluate aggregate ***,a particle library capable of characterizing aggregate morphology distribution is established based on the statistics of the corresponding morphological characteristics of particle *** model reliability is validated by carrying out a series of experimental and numerical penetration tests with nine different *** established particle library can be used to model aggregate mixtures and the proposed simulation framework is promising for optimizing the mixture gradation design numerically.

关键词： Particle library Discrete element method 3D laser scanning Coarse aggregate Morphology characterization Gradation design

Chen Jiayong:Pioneer in hydrometallurgy and chemical engineering disciplines

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Chinese Journal of Chemical Engineering 2022年第1期35卷 2-5页

作者： Zai-sha Mao Huizhou Liu Chao Yang Institue of Process Engineering Chinese Academy of SciencesBeijing 100190China

*** Jiayong(Chia-Yung)was born on Feb.17,1922 in a prestigous intellectual clan at Jintang County,Sichuan Province,*** receiving early education at the Chengdu County Middle School(now Chengdu 7th School),he was admitted as an undergraduate student to the Department of Chemical Engineering,the National Central University at the city of Chongqing from 1939 through 1943 during the Anti-Japanese *** graduation,he continued to work as a teaching assistant for both the inorganic and organic chemistry courses.

关键词： Chongqing Pioneer admitted

Fatigue life research and experimental verification of superalloy thin-walled structures subjected to thermal-acoustic loads

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Chinese Journal of Aeronautics 2020年第2期33卷 598-608页

作者： Jian WANG Fengtong ZHAO Yundong sha Song GU Department of Aircraft Maintenance Engineering Chengdu Aeronautic PolytechnicChengdu 610100China Liaoning Key Laboratory of Advanced Test Technology for Aeronautical Propulsion System Shenyang Aerospace UniversityShenyang 110136China

Rapid alternating stress is formed in structure subjected to harsh thermal-acoustic loads,which will affect fatigue performance and reduce fatigue life ***,fatigue experiment of superalloy thin-walled structure was carried out to obtain fatigue damage location and failure time of the experiment specimen,and S-iN curves of superalloy thin-walled structure at 723 K were ***,dynamic response simulation of superalloy thin-walled structure under the same load as experiment was implemented,and fatigue life was estimated based on the fatigue life prediction model which mainly included:improved rain-flow counting method,Morrow average stress model and Miner linear cumulative damage ***,comparisons between simulation solutions and experimental results achieved a consistency,which verified the validity of the Fatigue Life Prediction Model(FLPM).Moreover,taking a rectangle plate as the analysis object,the distributions of Fain-low circulation blocks and damage levels of the structure were discussed ***,current research indicates that in pre-buckling the structure is in softened area and fatigue life decreases with the increase of temperature;in post-buckling the structure is in hardened area and fatigue life increases with the increase of temperature within a certain range.

关键词： Experimental verification Fatigue life Improved rain-flow counting method Rain-flow cycle matrix Rain-flow damage matrix Thermal-acoustic load Thin-walled structures

Umbelliferone ameliorates renal function in diabetic nephropathy rats through regulating inflammation and TLR/NF-κB pathway

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Chinese Journal of Natural Medicines 2019年第5期17卷 346-354页

作者： WANG Han-Qing WANG sha-sha Chiufai Kuok WANG Qi CHENG Xiao-Lan College of Pharmacy Ningxia Medical University School of Rehabilitation Medicine Binzhou Medical University School of Health Sciences Macao Polytechnic Institute Nanjing Dorra Pharmaceutical Co. Ltd. Laboratory of Cellular and Molecular Biology Jiangsu Province Academy of Traditional Chinese Medicine

Diabetic nephropathy(DN) is a leading cause of renal failure, contributing to severe morbidity and mortality in diabetic patients. Umbelliferae(Umb) has been well characterized to exert protective effects in diabetes. However, the action and mechanism of Umb in DN remains unclear. In this work, we studied the effect of Umb in a streptozotocin(STZ)-induced DN rat model and explore its underlying mechanism. DN rats were treated with Umb(20, 40 mg·kg^(-1)) or irbesartan(15 mg·kg^(-1)) for 4 weeks. Levels of serum glucose, insulin, blood uric acid, creatinine, triglycerides(TG) and total cholesterol(TC) were measured by commercial assay kits,respectively. Histopathological changes and inflammatory cytokine levels including IL-6, IL-1β and TNF-α in the kidney were also evaluated. Alterations in the expression of podocin, CD2 AP and TLR/NF-κB were assessed by western blotting. Our results showed that Umb reduced renal injury in DN rat model, as evidenced by the decrease in blood glucose, 24 h urinary protein, serum creatinine,and blood uric acid. Umb also significantly ameliorated the renal histopathological alteration, and down-regulated the expression of epithelial-to-mesenchymal transition-related molecular markers podocin and CD2AP. Moreover, Umb inhibited TLR2, TLR4, MyD88 expressions, NF-κB activation and considerably reduced levels of other downstream inflammatory molecules(TNF-α, IL-6, IL-1β).These findings indicated that Umb improved renal function through regulating inflammation and TLR/NF-κB pathway, suggesting the potential efficacy of Umb in DN treatment.

关键词： Diabetic nephropathy Umbelliferone Streptozotocin Inflammation TLR/NF-κB pathway

Nanoparticle Dispersion and Glass Transition Behavior of Polyimide-grafted Silica Nanocomposites

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Chinese Journal of Polymer Science 2020年第1期38卷 100-108,I0008页

作者： sha-Ni Hu Yu Lin Guo-Zhang Wu shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology

How to control the spatial distribution of nanoparticles to meet different performance requirements is a constant challenge in the field of polymer *** studies have been focused on the flexible polymer chain *** this study,the rigid polyimide(PI) chain grafted silica particles with different grafting chain lengths and grafting densities were prepared by "grafting to" method,and the influence of polymerization degree of grafted chains(N),matrix chains(P),and grafting density(a) on the spatial distribution of nanoparticles in the PI matrix was *** glass transition temperature(Tg) of PI composites was systematically investigated as *** results show that silica particles are well dispersed in polyamic acid composite systems,while aggregation and small clusters appear in PI nanocomposites after thermal ***,the particle size has no impact on the spatial distribution of *** σ·N0.5<<(N/P)2,the grafted and matrix chains interpenetrate,and the frictional resistance of the segment increases,resulting in restricted relaxation kinetics and Tg increase of the PI composite *** addition,smaller particle size and longer grafted chains are beneficial to improving Tg of composites These results are all propitious to complete the microstructure control theory of nanocomposites and make a theoretical foundation for the high performance and multi-function of PI nanocomposites.

关键词： Polyimide grafted nanoparticle Dispersion morphology Glass transition temperature

Universality of an improved photosynthesis prediction model based on PSO-SVM at all growth stages of tomato

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International Journal of Agricultural and Biological Engineering 2017年第2期10卷 63-73页

作者： Li Ting Ji Yuhan Zhang Man sha sha Li Minzan Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083China Key Laboratory of Agricultural Information Acquisition Technology Ministry of AgricultureChina Agriculture UniversityBeijing 100083China Beijing Research Institute of Uranium Geology Beijing 100029China

CO_(2)concentration is an environmental factor affecting photosynthesis and consequently the yield and quality of *** this study,a photosynthesis prediction model for the entire growth stage of tomatoes was constructed to elevate CO_(2)level on the basis of crop requirements and to evaluate the effect of CO_(2)elevation on leaf *** effect of CO_(2)enrichment on tomato photosynthesis was investigated using two CO_(2)enrichment treatments at the entire growth stage.A wireless sensor network-based environmental monitoring system was used for the real-time monitoring of environmental factors,and the LI-6400XT portable photosynthesis system was used to measure the net photosynthetic rate of tomato *** input variables for the model,environmental factors were uniformly preprocessed using independent component ***,the photosynthesis prediction model for the entire growth stage was established on the basis of the support vector machine(SVM)*** particle swarm optimization(PSO)was also used to search for the best parameters c and g of ***,the relationship between CO_(2)concentration and photosynthetic rate under varying light intensities was predicted using the established model,which can determine CO_(2)saturation points at the various growth *** determination coefficients between the simulated and observed data sets for the three growth stages were 0.96,0.96,and 0.94 with the improved PSO-SVM and 0.89,0.87,and 0.86 with the original *** results indicate that the improved PSO-SVM exhibits a high prediction *** study provides a basis for the precise regulation of CO_(2)enrichment in greenhouses.

关键词： photosynthesis greenhouse tomato CO2 enrichment photosynthesis prediction model wireless sensor network environmental monitoring system

Will polycentric cities cause more CO2 emissions? A case study of 232 Chinese cities

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Journal of Environmental Sciences 2020年第10期32卷 33-43页

作者： Wei sha Ying Chen Jiansheng Wu Zhenyu Wang Key Laboratory for Urban Habitat Environmental Science and Technology School of Urban Planning and DesignPeking UniversityShenzhen 518055China Laboratory for Earth Surface Processes Ministry of EducationCollege of Urban and Environmental SciencesPeking UniversityBeijing 100871China

From 2000 to 2010 China experienced rapid economic development and *** cities in economically developed areas have developed from a single-center status to *** this study,we used exploratory spatial data analysis (ESDA) to identify the population centers,which identified 232 cities in China as having urban *** was used to represent urban agglomeration,and POLYD (representing how far is the city’s sub-centers to the main center),POLYC (representing the number of a city’s centers),and POLYP (representing the population distributed between the main center and the sub-centers) were used to indicate urban *** light data were used to determine the CO2 emissions from various cities in China.A mixed model was used to study the impact of urban aggregation and polycentric data on the CO2 emission efficiency in 2000 and *** study found that cities with higher compactness were distributed in coastal areas,and the cities with higher multicentricity were distributed in the Yangtze River Delta and shandong *** more compact the city was,the less conducive it was to improving CO2 emission *** development of the city was conducive to improving the CO2 emission efficiency,but the number of urban centers had no significant relationship with the CO2 emission *** research showed that the compactness and multicentricity of the city had an impact on the CO2 emission efficiency and provided some planning suggestions for the low carbon development of the city.

关键词： CO_2 emission efficiency polycentricity compactness Chinese cities

A Study on Quasi-orthogonal M-ary Chirp Modulation

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Chinese Journal of Electronics 2019年第5期28卷 1053-1058页

作者： YANG Liu ZHANG Fangqi ZHENG Guoxin sha Jiajun Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai Institute for Advanced Communication and Data ScienceShanghai University School of Electronic and Information Shanghai Dianji University Maglev Transportation Engineering R&D Center The Key Laboratory of Road and Traffic Engineering Ministry of Education Tongji University

This paper proposes and studies a novel M-ary chirp modulation scheme adopting quasi-orthogonal waveforms. The Symbol error probability(SEP) of M-ary modulation over Additive white Gaussian noise(AWGN)channel is derived based on coherent detection, which is a function of modulation factor and waveform ***, the SEP is investigated over a channel limited by a nominal bandwidth. Both theoretical analysis and simulations prove that the SEP performance of the proposed 8-ary chirp modulation outperforms that of conventional 8 Phase shift keying(8PSK) with the same bandwidth efficiency.

关键词： Chirp modulation Correlation coefficient Quasi-orthogonal waveform

Microstructure and wear behavior of Mo–60Si–5B coating doped with 0.5 at% La by spark plasma sintering

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Progress in Natural Science:Materials International 2022年第6期32卷 752-757页

作者： Zilong Wu Kanglu Feng Jiangbo sha Chungen Zhou School of Materials Science and Engineering Beihang University

Mo-60Si-5B coating doped with 0.5 at% La was prepared on niobium silicon based alloy by spark plasma *** microstructure and wear behavior of the 0.5La-Mo-60Si-5B（0.5La-MSB） coating were *** results show that the mean grain sizes of the Mo-60Si-5B（0La-MSB） and 0.5La-MSB coatings are calculated to be 3.27 μm and 2.85 μm,*** addition of La plays a role of refining the grains of 0.5La-MSB *** specific wear rate of 0.5La-MSB coating is decreased by up to 26.8% at the oscillation frequency of 20 Hz and the sliding load of 11 N compared to 0La-MSB *** anti-friction performance of Mo-60Si-5B coating is modified by the addition of 0.5 at.% *** improvement of anti-friction performance of the Mo-60Si-5B coating is due to the increased hardness and the provided lubrication function by La2O3.

关键词： Metal coatings La2O3 Nanoindentation Wear behavior