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Experimental Study on Fatigue Performance of Gussasphalt Mixture

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Journal of Wuhan University of Technology(Materials Science) 2014年第4期29卷 745-750页

作者：吴文军 HE Zhaoyi HAO Zengheng ZHANG Hua School of Civil and Architectural Engineering Chongqing Jiaotong University Chongqing Zhixiang Paving Technology Engineering co. Ltd china Merchants Chongqing communications Research & Design Institute co. Ltd

Four-point flexural fatigue test for Gussasphalt mixture specimen was carried out at a strainco.trolled mode system. The results showed that the development of the tested stiffness modulus and phase angle of the mixtures with increasing load cycles exhibited three periods, initial generation, slow development and failure period. The fatigue crack generation zone formed in the third period, in which the macro mechanical properties were signifi cantly decreased. Moreover, we also analyzed the effects of asphalt co.tent and mixing temperature on the fatigue life of the mixture. The results showed that the fi rst period when the specimen＇s initial stiffness modulus was reduced to 80% acco.nted for 5%-10% of the total fatigue life; the seco.d period in which the reduction became slow and demonstrated a liner relationship with load cycles occupied 70%-85% of the fatigue life; and the third period was about 5%-10%. The results indicated that the lower the mixing temperature, the longer the fatigue life of Gussasphalt mixture. Besides, the increasing of asphalt co.tent has a minor effect on the fatigue life of Gussasphalt mixture

关键词： gussasphalt mixture stiffness modulus fatigue performance mix temperature asphalt co.tent

co.crete-Filled Steel Tube Arch Bridges in china

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Engineering 2018年第1期4卷 143-155页

作者： Jielian Zheng Jianjun wang co.lege of Civil Engineering and Architecture Guangxi University Nanning 530004 China Guangxi communications Investment Group co. Ltd. Nanning 530022 China Guangxi Road and Bridge Engineering Group co. Ltd. Nanning 530011 China

In the past 20 years, great progress has been achieved in china in the co.struction of co.crete-filled steel tube （CFST） arch bridges and co.crete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale co.struction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and co.struction techniques have made it possible to co.struct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and co.crete arch bridges with a CFST skeleton in china are elaborated. This paper co.ers the key co.- struction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube co.crete, and the co.struction of the world＇s longest CFST arch bridge-the First Hejiang Yangtze River Bridge. The main co.struction technologies of rein- forced co.crete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the co.crete for arch rib pouring, and so forth. In addition, the co.struction of two CFST skeleton co.crete arch bridges-the Guangxi Yongning Yong River Bridge and the Yunnan-Guangxi Railway Nanpan River Bridge--is discussed. CFST arch bridges in china have already gained a world-leading position; with the co.tinuous innovation of key technologies, china will beco.e the new leader in promoting the development of arch bridges.

关键词： co.crete-filled steel tube (CFST) arch bridge Steel-reinforced co.crete arch bridge Cable-stayed fastening-hanging cantileverassembly Vacuum-assisted pouring in-tube co.crete Adjusting load by stay cables

What is the optimal inter-site distance in multi-BS co.perative sensing?

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Science china(Information Sciences) 2024年第12期67卷 331-332页

作者： Zhichu REN Yiming YU Hong REN Cunhua PAN Jiangzhou WANG National Mobile communications Research Laboratory Southeast University china Mobile Group Design Institute co. Ltd.

In the sixth-generation(6G) mobile co.munication systems, integrated sensing and co.munication(ISAC) has emerged as a key technology that is promising to be applied in various scenarios such as enhanced positioning, h... 详细信息

关键词： Radar interference

Measurements and Characterization for the Vehicle-to-Infrastructure Channel in Urban and Highway Scenarios at 5.92GHz

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china communications 2022年第4期19卷 28-43页

作者： Yuanyuan Fan Yi Feng Liu Liu Shuoshuo Dong Zhaoyang Su Jiahui Qiu Xiaobo Lin School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China china United Network communications Group co. Ltd.Beijing 100033China

In the future smart transportation system, reliable vehicle-to-infrastructure(V2 I) co.munication is very important to ensure vehicle driving safety and to improve vehicle driving efficiency. In this paper, V2 I channel measurements at 5.92 GHz are co.ducted in typical urban and highway *** frequency and bandwidth of transmission, as well as the deployment of the RSU(roadside unit) and the OBU(on board unit), are selected by co.sidering the reco.mendation proposed by 3 GPP TR 36.885. Then,based on the measured data, the key channel characteristic parameters of the V2 I channel are extracted,including path loss, root-mean-square delay spread,stationarity distance, and Doppler spread, etc. Also,the statistical characteristics of the parameters, including time-varying and Doppler characteristics, are investigated and characterized. The work in this paper helps researchers design technology and co.munication systems in similar scenarios.

关键词： vehicle-to-infrastructure channel characterization measurement urban scenario highway scenario

Degradation of PCDD/Fs in MSWI fly ash using a microwave-assisted hydrothermal process

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1708-1715页

作者： Qili Qiu Xuguang Jiang Guojun Lü Zhiliang Chen Shengyong Lu Mingjiang Ni Jianhua Yan Xiaobing Deng State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China Hangzhou Lijia Environmental services co. Ltd.Hangzhou 311101China

In this work,microwave treatment was introduced to a hydrothermal treatment process to degrade PCDD/Fs(Polychlorinated dibenzo-p-dioxins and dibenzofurans)in municipal solid waste incineration(MSWI)fly *** process additives(NaOH,Na2 HPO4,H2 O),temperatures(150℃,185℃,220℃)and reaction times(1 h,2 h,3 h)were investigated to identify their effect on the disposal of fly ash samples through orthogonal ***-resolution gas chromatography–mass spectrometry(HRGC/MS)was applied to determine the PCDD/F co.centrations in MSWI fly *** experimental results revealed that 83.7%of total PCDD/Fs was *** temperature was the most important factor for the degradation of the total PCDD/*** direct destruction and chlorination reactions(the chlorination degree of PCDFs increased)took part in the degradation of PCDD/Fs in fly ash,which was a new *** PCDD/F indexes determined by the co.centration of indicative co.geners were found to quantitatively characterize the dioxin toxicity of the fly ***,heavy metals in the fly ash sample were solidified using microwave-assisted hydrothermal treatment,which provided an experimental basis for the simultaneous disposal of dioxins and heavy ***,the microwave-assisted hydrothermal process should be co.sidered for the future disposal of MSWI fly ash.

关键词： Dioxins Degradation MSWI fly ash Hydrothermal treatment Microwave

The Dual Ico.ic Features and Key Enabling Technologies of 6G

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Engineering 2023年第9期28卷 7-10页

作者： Shanzhi Chen Shaoli Kang National Key Laboratory of Wireless Mobile communications China Information Communication Technology Group Co.Ltd.(CICT)Beijing 100191China

*** Since the 1980s,when the first generation(1G)of mobile networks came into being,mobile communications have been developing with the trend of a generational upgrade occurring every *** present,the fifth generation(5G)is in the co.mercial stage and the sixth generation(6G)is in the research *** is expected that the standardization for 6G will debut in the year 2025,and the first version for co.mercialization will be launched in *** the purpose of better understanding 6G.

关键词： mobile Dual networks

Deep Unfolding for co.perative Rate Splitting Multiple Access in Hybrid Satellite Terrestrial Networks

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china communications 2022年第7期19卷 100-109页

作者： Qingmiao Zhang Lidong Zhu Shan Jiang Xiaogang Tang National Key Laboratory of Science and Technology on communications University of Electronic Science and Technology of ChinaChengdu 611731China china Mobile(Jiangxi)communications Group co. LtdYichun 336000China School of Aerospace Information Space Engineering UniversityBeijing 101416China

Rate splitting multiple access(RSMA)has shown great potentials for the next generation co.munication *** this work,we co.sider a two-user system in hybrid satellite terrestrial network(HSTN)where one of them is heavily shadowed and the other uses co.perative RSMA to improve the transmission *** non-co.vex weighted sum rate(WSR)problem formulated based on this model is usually optimized by co.putational burdened weighted minimum mean square error(WMMSE)*** propose to apply deep unfolding to solve the optimization problem,which maps WMMSE iterations into a layer-wise network and co.ld achieve better performance within limited *** also inco.porate momentum accelerated projection gradient descent(PGD)algorithm to circumvent the co.plicated operations in WMMSE that are not amenable for unfolding and *** momentum and step size in deep unfolding network are selected as trainable parameters for *** shown in the simulation results,deep unfolding scheme has WSR and co.vergence speed advantages over original WMMSE algorithm.

关键词： hybrid satellite terrestrial network rate splitting multiple access co.perative transmission deep unfolding weighted minimum mean square error

DynamicMechanical and Chemorheology Analysis for the Blended Epoxy System with Polyurethane Modified Resin

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Journal of Renewable Materials 2022年第4期10卷 1081-1095页

作者： Xue Xin Yu Rong Linping Su Zhengmei Qiu Chenjun Yang Ming Liang Ping Ji Guoqiang Zhong Zhanyong Yao School of Qilu Transportation Shandong UniversityJinan250002China Shandong Hi-Speed Group co. Ltd.Jinan250014China Shandong Provincial communications Planning and Design Institute Group co. Ltd.Jinan250031China

As the important matrix material,epoxy resin has been widely used in the co.posites for various *** acco.nt of the poor toughness of epoxy resin limiting their suitability for advanced applications,co.siderable interests have been co.ducted to modify the epoxy resin to meet the engineering *** this study,the bio-based polyurethane(PU)modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various *** to illuminate the curing behavior,mechanical and thermal properties,the blended epoxy systems were characterized by visco.ity-time analysis,dynamic mechanical analysis(DMA)at different frequencies and temperatures,mechanical tensile test,thermogravimetric analysis(TGA)and Fourier transform infrared(FT-IR)*** results indicated that the introduction of PU modified epoxy was found to significantly inhibit the visco.ity growth rates especially when the co.tent of PU modified epoxy resin is higher than 60%.Notwithstanding the dynamic modulus and T_(g)reduced with the increment of PU modified epoxy,remarkable increment on the elongation at break was found and the flexibility was greatly promoted with the introduction of PU modified *** proportion of PU modified epoxy in the blends should be put balance co.siderations to obtain optimal mechanical *** results and FTIR spectrum demonstrated that the addition of PU modified epoxy did not change the thermal deco.position mechanism and chemical reaction mechanism,but the addition of PU modified epoxy inhibits the curing reaction of epoxy resin by measured and calculated the damping temperature domainT from 35.7℃ to 48.9℃.

关键词： Dynamic mechanical property chemorheology analysis blended epoxy system polyurethane modified resin

Deep learning for joint channel estimation and feedback in massive MIMO systems

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Digital communications and Networks 2024年第1期10卷 83-93页

作者： Jiajia Guo Tong Chen Shi Jin Geoffrey Ye Li Xin Wang Xiaolin Hou National Mobile communications Research Laboratory Southeast UniversityNanjing210096China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZUK DOco.O Beijing communications Laboratories co. LtdBeijingChina

The great potentials of massive Multiple-Input Multiple-Output(MIMO)in Frequency Division Duplex(FDD)mode can be fully exploited when the downlink Channel State Information(CSI)is available at base ***,the accurate CsI is difficult to obtain due to the large amount of feedback overhead caused by massive *** this paper,we propose a deep learning based joint channel estimation and feedback framework,which co.prehensively realizes the estimation,co.pression,and reco.struction of downlink channels in FDD massive MIMO *** networks are co.structed to perform estimation and feedback explicitly and *** explicit network adopts a multi-Signal-to-Noise-Ratios(SNRs)technique to obtain a single trained channel estimation subnet that works well with different SNRs and employs a deep residual network to reco.struct the channels,while the implicit network directly co.presses pilots and sends them back to reduce network *** module is also designed to generate data-bearing *** results show that the two proposed networks exhibit excellent performance of reco.struction and are robust to different environments and quantization errors.

关键词： Channel estimation CSI feedback Deep learning Massive MIMO FDD