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Microstructure evolution and strengthening mechanism of high -performance powder metallurgy TA15 titanium alloy by hot rolling

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1426-1436页

作者： Ying Gao ce zhang Jiazhen zhang Xin Lu Beijing Advanced Innovation center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsInstitute for Advanced Ma-terials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research center for Advanced Rolling Technology National Engineering Research Center for Flat Rolling EquipmentInstitute of Engin-eering TechnologyUniversity of Science and Technology BeijingBeijing 100083China

Hot deformation of sintered billets by powder metallurgy(PM)is an effective preparation technique for titanium alloys,which is more significant for high-alloying alloys.In this study,Ti–6.5Al–2Zr–Mo–V(TA15)titanium alloy plates were prepared by cold press-ing sintering combined with high-temperature hot rolling.The microstructure and mechanical properties under different process paramet-ers were investigated.Optical microscope,electron backscatter diffraction,and others were applied to characterize the microstructure evolution and mechanical properties strengthening mechanism.The results showed that the chemical compositions were uniformly dif-fused without segregation during sintering,and the closing of the matrix craters was accelerated by increasing the sintering temperature.The block was hot rolled at 1200℃ with an 80%reduction under only two passes without annealing.The strength and elongation of the plate at 20–25℃ after solution and aging were 1247 MPa and 14.0%,respectively,which were increased by 24.5%and 40.0%,respect-ively,compared with the as-sintered alloy at 1300℃.The microstructure was significantly refined by continuous dynamic recrystalliza-tion,which was completed by the rotation and dislocation absorption of the substructure surrounded by low-angle grain boundaries.After hot rolling combined with heat treatment,the strength and plasticity of PM-TA15 were significantly improved,which resulted from the dense,uniform,and fine recrystallization structure and the synergistic effect of multiple slip systems.

关键词： elemental powder powder metallurgy titanium alloy hot rolling strength and plasticity

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A Survey and Tutorial of EEG-Based Brain Monitoring for Driver State Analysis

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IEEE/CAA Journal of Automatica Sinica 2021年第7期8卷 1222-1242页

作者： ce zhang Azim Eskandarian Virginia Tech Mechanical Engineering Department ASIM Lab Virginia 24061-0131 USA

The driver’s cognitive and physiological states affect his/her ability to control the vehicle.Thus,these driver states are essential to the safety of automobiles.The design of advanced driver assistance systems(ADAS)or autonomous vehicles will depend on their ability to interact effectively with the driver.A deeper understanding of the driver state is,therefore,paramount.Electroencephalography(EEG)is proven to be one of the most effective methods for driver state monitoring and human error detection.This paper discusses EEG-based driver state detection systems and their corresponding analysis algorithms over the last three decades.First,the commonly used EEG system setup for driver state studies is introduced.Then,the EEG signal preprocessing,feature extraction,and classification algorithms for driver state detection are reviewed.Finally,EEG-based driver state monitoring research is reviewed in-depth,and its future development is discussed.It is concluded that the current EEGbased driver state monitoring algorithms are promising for safety applications.However,many improvements are still required in EEG artifact reduction,real-time processing,and between-subject classification accuracy.

关键词： Advanced driver assistance systems(ADAS) data analysis electroencephalography(EEG) intelligent vehicles machine learning algorithms neural network.

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Comparison of time trends in the incidence of primary liver cancer between China and the United States: an age-period-cohort analysis of the Global Burden of Disease 2019

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Chinese Medical Journal 2022年第17期135卷 2035-2042页

作者： Zhiyong Zou Zuofeng zhang ce Lu Hui Wang Iinstitute of Child and Adolescent Health School of Public HealthPeking University Health Science CenterBeijing 100191China Department of Epidemiology Fielding School of Public HealthUniversity of CaliforniaLos AngelesCAUSA Department of Epidemiology School of Public HealthNanjing Medical UniversityNanjngJjiangsu 21161China Department of Maternal and Child Health School of Public HealthPeking University Health Science CenterBeijing 100191China

Background::China and the United States(US)ranked first and third in terms of new liver cancer cases and deaths globally in 2020.Therefore,a comprehensive assessment of trends in the incidence of primary liver cancer with four major etiological factors between China and the US during the past 30 years with age-period-cohort(APC)analyses is warranted.Methods::Data were obtained from the Global Burden of Disease 2019,and period/cohort relative risks were estimated by APC modeling from 1990 to 2019.Results::In 2019,there were 211,000 new liver cancer cases in China and 28,000 in the US,accounting for 39.4%and 5.2%of global liver cancer cases,respectively.For China,the age-standardized incidence rate(ASIR)consecutively decreased before 2005 but increased slightly since then,whereas the ASIR continuously increased in the US.Among the four etiological factors of liver cancer,the fastest reduction in incidence was observed in hepatitis B virus-related liver cancer among Chinese women,and the fastest increase was in nonalcoholic steatosis hepatitis(NASH)-related liver cancer among American men.The greatest reduction in the incidence of liver cancer was observed at the age of 53 years in Chinese men(-5.2%/year)and 33 years in Chinese women(-6.6%/year),while it peaked at 58 years old in both American men and women(4.5%/year vs.2.8%/year).Furthermore,the period risks of alcohol-and NASH-related liver cancer among Chinese men have been elevated since 2013.Simultaneously,leveled-off period risks were observed in hepatitis C viral-related liver cancer in both American men and women.Conclusions::Currently,both viral and lifestyle factors have been and will continue to play an important role in the time trends of liver cancer in both countries.More tailored and efficient preventive strategies should be designed to target both viral and lifestyle factors to prevent and control liver cancer.

关键词： Alcohol use-related liver cancer China Global Burden of Disease Hepatitis Hepatitis B virus Hepatitis C Incidence Liver neoplasms Life Style Middle aged Non-alcoholic fatty liverdisease United States

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Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient catalytic degradation of organic dyes

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Frontiers of Chemical Science and Engineering 2023年第7期17卷 893-905页

作者： Fan zhang ce Gao Shang-Ru Zhai Qing-Da An Liaoning Key Lab of Lignocellulose Chemistry and BioMaterials Liaoning Collaborative Innovation Center for Lignocellulosic BiorefineryCollege of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian 116034China

A novel alginate/poly(acrylic acid/acrylamide)double-network hydrogel composite with silver nanoparticles was successfully fabricated using the sol–gel method.The presence of carboxyl and amide groups in the network structure provided abundant active sites for complexing silver ions,facilitating the in situ reduction and confinement of silver nanoparticles.In batch experiments,the optimal silver loading was 20%,and 5 mmol·L^(–1) of p-nitrophenol was completely degraded in 113 s with a rate constant value of 4.057×10^(−2) s^(–1).In the tap water system and simulated seawater system,the degradation time of p-nitrophenol at the same concentration was 261 and 276 s,respectively,with a conversion rate above 99%.In the fixed-bed experiment,the conversion rate remained above 74%after 3 h at a flowing rate of 7 mL·min^(–1).After 8 cycling tests,the conversion rate remained at 98.7%.Moreover,the catalyst exhibited outstanding performance in the degradation experiment of four typical organic dyes.

关键词： double-network hydrogel dye degradation silver nanoparticles alginate

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Temporal sequence Object-based CNN(TS-OCNN) for crop classification from fine resolution remote sensing image time-series

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The Crop Journal 2022年第5期10卷 1507-1516页

作者： Huapeng Li Yajun Tian ce zhang Shuqing zhang Peter MAtkinson Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130012JilinChina Lancaster Environment centre Lancaster UniversityLancaster LA14YQUK Faculty of Science and Technology Lancaster UniversityLancaster LA14YRUK

Accurate crop distribution mapping is required for crop yield prediction and field management. Due to rapid progress in remote sensing technology, fine spatial resolution(FSR) remotely sensed imagery now offers great opportunities for mapping crop types in great detail. However, within-class variance can hamper attempts to discriminate crop classes at fine resolutions. Multi-temporal FSR remotely sensed imagery provides a means of increasing crop classification from FSR imagery, although current methods do not exploit the available information fully. In this research, a novel Temporal Sequence Object-based Convolutional Neural Network(TS-OCNN) was proposed to classify agricultural crop type from FSR image time-series. An object-based CNN(OCNN) model was adopted in the TS-OCNN to classify images at the object level(i.e., segmented objects or crop parcels), thus, maintaining the precise boundary information of crop parcels. The combination of image time-series was first utilized as the input to the OCNN model to produce an ‘original’ or baseline classification. Then the single-date images were fed automatically into the deep learning model scene-by-scene in order of image acquisition date to increase successively the crop classification accuracy. By doing so, the joint information in the FSR multi-temporal observations and the unique individual information from the single-date images were exploited comprehensively for crop classification. The effectiveness of the proposed approach was investigated using multitemporal SAR and optical imagery, respectively, over two heterogeneous agricultural areas. The experimental results demonstrated that the newly proposed TS-OCNN approach consistently increased crop classification accuracy, and achieved the greatest accuracies(82.68% and 87.40%) in comparison with state-of-the-art benchmark methods, including the object-based CNN(OCNN)(81.63% and85.88%), object-based image analysis(OBIA)(78.21% and 84.83%), and standard pixel-wise CNN(79.18%and 82.90%). The proposed approach is

关键词： Convolutional neural network Multi-temporal imagery Object-based image analysis(OBIA) Crop classification Fine spatial resolution imagery

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Land cover classification from remote sensing images based on multi-scale fully convolutional network

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Geo-Spatial Information Science 2022年第2期25卷 278-294页

作者： Rui Li Shunyi Zheng Chenxi Duan Libo Wang ce zhang School of Remote Sensing and Information Engineering Wuhan UniversityWuhanChina Faculty of Geo-Information Science and Earth Observation(ITC) University of TwenteEnschedeThe Netherlands The State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina Lancaster Environment centre Lancaster UniversityLancasterUK UK centre for Ecology&Hydrology LancasterUK

Although the Convolutional Neural Network(CNN)has shown great potential for land cover classification,the frequently used single-scale convolution kernel limits the scope of informa-tion extraction.Therefore,we propose a Multi-Scale Fully Convolutional Network(MSFCN)with a multi-scale convolutional kernel as well as a Channel Attention Block(CAB)and a Global Pooling Module(GPM)in this paper to exploit discriminative representations from two-dimensional(2D)satellite images.Meanwhile,to explore the ability of the proposed MSFCN for spatio-temporal images,we expand our MSFCN to three-dimension using three-dimensional(3D)CNN,capable of harnessing each land cover category’s time series interac-tion from the reshaped spatio-temporal remote sensing images.To verify the effectiveness of the proposed MSFCN,we conduct experiments on two spatial datasets and two spatio-temporal datasets.The proposed MSFCN achieves 60.366%on the WHDLD dataset and 75.127%on the GID dataset in terms of mIoU index while the figures for two spatio-temporal datasets are 87.753%and 77.156%.Extensive comparative experiments and abla-tion studies demonstrate the effectiveness of the proposed MSFCN.

关键词： Spatio-temporal remote sensing images Multi-Scale Fully Convolutional Network land cover classification

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Do egg cell-secreted aspartic proteases promote gamete attachment?

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Journal of Integrative Plant Biology 2023年第1期65卷 3-6页

作者： Xuecheng zhang Xiaobo Yu ce Shi Thomas Dresselhaus Meng-Xiang Sun State Key Laboratory of Hybrid Rice College of Life Sciences Wuhan UniversityWuhan 430072 China Bamboo Diseases and Pest Control and Resources Development Key Laboratory of Sichuan Province College of Life Science Leshan Normal UniversityLeshan 614000 China cell Biology and Plant Biochemistry University of Regensburg Regensburg 3193053 Germany

During the double fertilization process of flowering plants(angiosperms),pollen tubes transport a pair of immobile sperm cells toward and inside the embryo sac for fusion with egg and central cell,respectively.Male–female gamete interactions during fertilization are critical for reproductive success and seed development,and thus have interested biologists for decades.Compared to animals,little is known about gamete interaction mechanisms in angiosperms.

关键词： gamete fertilization interested

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Low-complexity PTS scheme based on phase factor sequences optimization

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Journal of Systems Engineering and Electronics 2018年第4期29卷 707-713页

作者： JI ce zhang Chao ZHU Wenjing School of Computer Science & Engineering Northeastern University

In this paper, a new partial transmit sequence（PTS）scheme with low computational complexity is proposed for the problems of high computational complexity in the conventional PTS method. By analyzing the relationship of candidate sequences in the PTS method under the interleaved partition method, it has been discovered that some candidate sequences generated by phase factor sequences have the same peak average power ratio（PAPR）. Hence, phase factor sequences can be optimized to reduce their searching times. Then, the computational process of generating candidate sequences can be simplified by improving the utilization of data and minimizing the calculations of complex multiplication. The performance analysis shows that, compared with the conventional PTS scheme, the proposed approach significantly decreases the computational complexity and has no loss of PAPR performance.

关键词： partial transmit sequence （PTS） peak average powerratio （PAPR） phase factor sequences optimization orthogonal frequency division multiplexing （OFDM） low computational com-plexity

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Effects of adverse pressure gradient on Reynolds stresses inturbulent boundary layers

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航空动力学报 2017年第2期32卷 463-469页

作者： LUO Xiao-tian ZHANG Ce MA Wei TENG Jin-fang School of Aeronautics and Astronautics Shanghai Jiao Tong University

The effects of adverse pressure gradient(APG)on Reynolds stresses in turbulent boundary layers(TBLs)with APG were analyzed.The difficulty of this work was attributable to the Reynolds stresses in TBLs with APG under two combined effects,i.e.:effect of upstream flow and effect of APG.The effect of upstream flow is an inherent effect no matter pressure gradient exists or not.The individual effect was analyzed from absolute developments of Reynolds stresses in TBLs with zero pressure gradient(ZPG)firstly.Effect of APG was then analyzed from absolute developments of Reynolds stresses in TBLs with APG.Result showed that,for absolute development of mean streamwise Reynolds stresses,APG accelerated its development in TBL with ZPG;for absolute development of mean normal or shear Reynolds stresses,APG increased their magnitude in the outer part,and decreased their extent of large value region.

关键词： turbulent boundary layer adverse pressure gradient zero pressure gradient Reynolds stresses flat plate

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A female in vivo haploid-induction system via mutagenesis of egg cell-specific peptidases

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Molecular Plant 2023年第2期16卷 471-480页

作者： Xuecheng zhang ce Shi Siling Li Bo zhang Pan Luo Xiongbo Peng Peng Zhao Thomas Dresselhaus Meng-Xiang Sun State Key Laboratory of Hybrid Rice College of Life SciencesWuhan UniversityWuhan 430072China Hubei Hongshan Laboratory Wuhan 430070China cell Biology and Plant Biochemistry University of RegensburgRegensburgGermany

Crop breeding schemes can be significantly accelerated by using(doubled)haploid plants.In vivo haploid induction has been applied in plant breeding for decades but is still not available for all crops and genotypes,and haploidization rates are generally very low.Therefore,methodological improvements to and new concepts for haploidization are required.Here,we report a novel system for the induction of haploid plants by mutating genes encoding egg cell-specific aspartic endopeptidases(ECSs).We show that after successful sperm–egg cell fusion,ECSs play a critical role to ensure male and female nucleus fusion after fertilization.The ecs1 ecs2 double mutant can induce haploids by both selfing and hybridization in Arabidopsis and ECS mutation is also capable of producing haploids in rice.In summary,our study develops a novel approach for maternal haploidization and provides new insights into the molecular basis of fertilization.

关键词： haploid induction egg cell maternal inducer semigamy fertilization

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