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High-performance martensitic stainless steel nanocomposite powder for direct energy deposition prepared by ball milling

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Rare Metals 2023年第7期42卷 2419-2432页

作者： Zhen Wang Shu-Rong Xu Qing-Xuan Sui Jiang Wang Bo Liu Hao Wen Tian-Yi Xiao Quan Yuan Feng-Jun Zhao Jun Liu School of Materials Science and Engineering Central South UniversityChangsha410083China jinchuan Nickel Cobalt Research and Design Institute Jinchuan Group Co.LtdJinchang737100China

Direct energy deposition(DED)has great potential for the production of stainless steel matrix nanocomposite ***,the propensity of nanoparticle agglomeration leads to the difficulty in realizing homogenous dispersion of nanoparticles in the *** this study,a series of agglomeration-free nanoWC-Co-reinforced 420 stainless steel matrix nanocomposite powders with high flowability were prepared by ball milling under the optimal *** effect of ball milling time on the properties of the composite powders was *** powder properties ensure the DED processing ***,the corresponding composites were fabricated by DED,and the effects of nano-WC-Co content on the properties of the composites were comprehensively *** contact angles between the single pass cladding layer and the substrate change with increasing nano-WC-Co content(decrease from 127.38°to 113.07°).The different contact angles will significantly influence the quality of the multipass cladding ***,the addition of nanoWC-Co leads not only to further grain refinement but also to more pronounced isotropy of the micros *** the increase in nano-WC-Co content,the corrosion resistance is significantly improved(62.28%lower corrosion current for 420-15 wt%nano-WC-Co than for 420).

关键词： Steel matrix composites Direct energy deposition(DED) Ball milling time Contact angle Microstructure Mechanical property

Flow behavior and microstructural evolution in nickel during hot deformation

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Rare Metals 2019年第7期38卷 675-682页

作者： Wen-Li Gao Shi-Zhen Lai Jie Teng Zhen-Tao Du Xue-Sheng Liu Yao-Wei Chang College of Materials Science and Engineering Hunan University. Changsha 410082 China jinchuan Nickel and Cobalt Research and Engineering Institute Jinchuan Group Nickel Alloy Co. Ltd.. Jinchang 737100 China

The hot deformation behavior of pure nickel with coarse, columnar grains in the temperature range of 950-1150 ℃ at intervals of 50℃ and in the strain rate range of 0.001-10.000 s^-1 at intervals of one order of magnitude was investigated by isothermal hot compressive testing with the compression ratio of 70%. The results reveal that the strain rate and the temperature strongly affect the flow stress during hot deformation and that flow stress increases with the increase in strain rate while decreases with temperature increasing. Moreover, the relationship among flow stress, strain rate and temperature can be represented by the Zener-Hollomon parameter with the calculated apparent activation energy of 312.403 kJ·mol^-1, and the variation of activation energy is sensitive to strain rate rather than temperature. In addition, the dynamic recrystallization (DRX) analysis reveals that the DRX behavior of nickel is evidently affected by both deformation temperature and strain rate and that the distinct mechanisms of nucleation are the bulging of serrated grain boundaries and the development of twinning.

关键词： Pure nickel Hot compression Flow behavior Microstructure Mechanism

An End-To-End Hyperbolic Deep Graph Convolutional Neural Network Framework

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 537-563页

作者： Yuchen Zhou Hongtao Huo Zhiwen Hou Lingbin Bu Yifan Wang Jingyi Mao Xiaojun Lv Fanliang Bu School of Information Network Security People’s Public Security University of ChinaBeijing100038China Institute of Computing Technology China Academy of Railway Sciences Corporation LimitedBeijing100081China

Graph Convolutional Neural Networks(GCNs)have been widely used in various fields due to their powerful capabilities in processing graph-structured ***,GCNs encounter significant challenges when applied to scale-free graphs with power-law distributions,resulting in substantial ***,most of the existing GCN models are shallow structures,which restricts their ability to capture dependencies among distant nodes and more refined high-order node features in scale-free graphs with hierarchical *** more broadly and precisely apply GCNs to real-world graphs exhibiting scale-free or hierarchical structures and utilize multi-level aggregation of GCNs for capturing high-level information in local representations,we propose the Hyperbolic Deep Graph Convolutional Neural Network(HDGCNN),an end-to-end deep graph representation learning framework that can map scale-free graphs from Euclidean space to hyperbolic *** HDGCNN,we define the fundamental operations of deep graph convolutional neural networks in hyperbolic ***,we introduce a hyperbolic feature transformation method based on identity mapping and a dense connection scheme based on a novel non-local message passing *** addition,we present a neighborhood aggregation method that combines initial structural featureswith hyperbolic attention *** the above methods,HDGCNN effectively leverages both the structural features and node features of graph data,enabling enhanced exploration of non-local structural features and more refined node features in scale-free or hierarchical *** results demonstrate that HDGCNN achieves remarkable performance improvements over state-ofthe-art GCNs in node classification and link prediction tasks,even when utilizing low-dimensional embedding ***,when compared to shallow hyperbolic graph convolutional neural network models,HDGCNN exhibits notable advantages and performance enhanceme

关键词： Graph neural networks hyperbolic graph convolutional neural networks deep graph convolutional neural networks message passing framework

Low-modal-crosstalk doped-fiber amplifiers in few-mode-fiber-based systems

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Photonics Research 2024年第8期12卷 1768-1775页

作者： SHUAILUO HUANG LEI SHEN GANG QIAO YUANPENG DING YUYANG GAO JIAN CUI BAOLONG ZHU SIYUAN LIU MINGQING ZUO JINGLONG ZHU LEI ZHANG JIE LUO YONGQI HE ZHANGYUAN CHEN JUHAO LI State Key Laboratory of Advanced Optical Communication Systems and Networks Peking UniversityBeijing 100871China State Key Laboratory of Optical Fiber and Cable Manufacture Technology Yangtze Optical Fibre and Cable Joint Stock Limited CompanyWuhan 430073China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Department of Networks China Mobile Communications Group Co.Ltd.Beijing 100033China Department of Fundamental Network Technology China Mobile Research InstituteBeijing 100053China Pengcheng Laboratory Shenzhen 518055China

Independent light propagation through one or multiple modes is commonly considered as a basic demand for mode manipulation in few-mode fiber(FMF)-or multimode fiber(MMF)-based optical systems such as transmission links,optical fiber lasers,or distributed optical fiber ***,the insertion of doped-fiber amplifiers always kills the entire effort by inducing significant modal *** this paper,we propose the design of doped-fiber amplifiers in FMF-based systems adopting identical multiple-ring-core(MRC)index profiles for both passive and doped fibers to achieve low modal *** develop the direct-glass-transition(DGT)modified chemical vapor deposition(MCVD)processing for precise fabrication of few-mode erbium-doped fibers(FM-EDFs)with MRC profiles of both refractive index and erbium-ion doping ***,a few-mode erbium-doped-fiber amplifier(FM-EDFA)with a maximum gain of 26.08 dB and differential modal gain(DMG)of 2.3 dB is realized based on fabricated FM-EDF matched with a transmission FMF supporting four linearly polarized(LP)*** the insertion of the FM-EDFA,60+60 km simultaneous LP_(01)∕LP_(11)∕LP_(21)∕LP_(02)transmission without inter-modal multiple-input multiple-output digital signal processing(MIMO-DSP)is successfully *** proposed design of low-modal-crosstalk doped-fiber amplifiers provides,to our knowledge,new insights into mode manipulation methods in various applications.

关键词： fiber crosstalk amplifiers

Correlation between carbon emissions,fuel consumption of vehicles and speed limit on expressway

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 631-642页

作者： Chao Gao Jinliang Xu Miao Jia Zhenhua Sun School of Highway Chang'an UniversityXi'an 710064China Shaoxing Communications Investment group Co. Ltd.Shaoxing 312000China

This paper aimed to investigate the correlation between carbon emissions,fuel consumption,and speed limit.A theoretical model was derived based on the energy conservation law,which expresses the relationship between vehicle's fuel consumption and ***,a total of 40 sets of fuel consumption data were collected through field tests to verify the accuracy of the theoretical model at different speeds and different road longitudinal slope *** fuel consumption was then converted to carbon emissions according to the carbon emission factors specified by Intergovernmental Panel on Climate Change(IPCC).In the field experiment,two types of cars and trucks,which are most common on the expressways in China,were ***,the travel speed under different posted speed limits was obtained through the previously established model,and the carbon emission changes of different vehicle types at different limited speeds are *** results show that the speed limit has a significant impact on fuel consumption and carbon *** the speed limit increased from 80 to 120 km/h,average vehicle speeds increased about 21%-27%,and fuel consumption and carbon emissions increased from approximately 33%-38%.Another interesting result was that the vehicle's fuel consumption and carbon emissions are only affected by *** results of the study explore the effect of speed limits on carbon emissions and provide evidence for road managers to set reasonable speed limits.

关键词： Vehicle carbon emission Vehicle fuel consumption Posted speed limit Average speed Road longitudinal slope

Fast Fourier transform convolution neural network accelerator based on overlap addition

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The Journal of China Universities of Posts and Telecommunications 2024年

作者： You Chen Li Dejian Feng Xi Shen Chongfei Wei Jizeng Liu Yu School of Microelectronics， Tianjin University College of Intelligence and Computing， Tianjin University Beijing Smart-Chip Microelectronics Technology Company limited

In convolutional neural networks（CNNs）， the floating point computation in the traditional convolution layer is enormous， and the execution speed of the network is limited by intensive computing， which makes it challenging to meet the real-time response requirements of complex applications. This work is based on the principle that the time domain convolution result equals the frequency domain dot multiplication result to reduce the amount of floating-point calculations for convolution. The input feature map and the convolution kernel are converted to the frequency domain by the fast Fourier transform（FFT）， and the corresponding dot multiplication is performed. Then the frequency domain result is converted back to the time domain， and the output result of the convolution is obtained. In the shared CNN， the input feature map is much larger than the convolution kernel， resulting in many invalid operations. The overlap addition method is proposed to reduce invalid calculations and speed up network execution better. This work designs a hardware accelerator for frequency domain convolution and verifies its efficiency on the Xilinx ZYNQ UltraScale+MPSoC ZCU102 board: comparing the calculation time of Visual Geometry group16(VGG16) under the ImageNet dataset， compared to traditional convolution accelerators， the hardware acceleration of frequency-domain convolution has improved performance by 8.5 times.

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Alkali Tolerance of Concrete Internal Curing Agent Based on Sodium Carboxymethyl Starch

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 82-90页

作者：陈梅花刘荣进 CHEN Ping JING Daiyan WAN Dandan FU Siyuan College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004China Guangxi Engineering and Technology Center for Utilization of Industrial Waste Residue in Building Materials Guilin 541004China Guangxi Maibu New Material limited Company Guilin 541004China

Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of *** alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using sodium carboxymethyl starch (CMS) with high hydrophilicity,acrylic acid (AA) containing anionic carboxylic group and acrylamide (AM) containing non-ionic amide group as the main raw *** results show that the ratio of CAA-ICA alkali absorption solution is higher than that existing ICA,which solves the low water absorption ratio of the ICA in alkali *** water absorption ratio of CAA-ICA in saturated Ca(OH)_(2) solution is 95.8 g·g^(-1),and the alkali tolerance coefficient is *** application of CAA-ICA in cement-based materials can increase the internal relative humidity and miniaturize the pore *** compressive strength of mortar increases up to 12.95%at 28 d,which provids a solution to overcome the reduction of the early strength.

关键词： alkali tolerance sodium carboxymethyl starch internal curing agent compressive strength

Prognostic value of cardiovascular magnetic resonance in immune checkpoint inhibitor-associated myocarditis:A systematic review and meta-analysis

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Cancer Innovation 2024年第3期3卷 22-32页

作者： Wenhua Song Nan Zhang Tonglian Lv Yang Zhao Guangping Li Gary Tse Tong Liu Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of CardiologyTianjin Institute of CardiologySecond Hospital of Tianjin Medical UniversityTianjinChina Department of Radiology Second Hospital of Tianjin Medical UniversityTianjinChina School of Nursing and Health Studies Hong Kong Metropolitan UniversityHong KongChina Cardiac Electrophysiology Unit Cardiovascular Analytics GroupPowerHealth LimitedHong KongChina

Background:The role of surgery in metastatic breast cancer(MBC)is currently *** novel statistical and deep learning(DL)methods promise to infer the suitability of surgery at the individual ***:The objective of this study was to identify the most applicable DL model for determining patients with MBC who could benefit from surgery and the type of surgery ***:We introduced the deep survival regression with mixture effects(DSME),a semi-parametric DL model integrating three causal inference *** models were trained to make individualized treatment *** who received treatments in line with the DL models'recommendations were compared with those who underwent treatments divergent from the *** probability weighting(IPW)was used to minimize *** effects of various features on surgery selection were visualized and quantified using multivariate linear regression and causal ***:In total,5269 female patients with MBC were *** was an independent protective factor,outperforming other models in recommend-ing surgery(IPW-adjusted hazard ratio[HR]=0.39,95%confidence interval[CI]:0.19–0.78)and type of surgery(IPW-adjusted HR=0.66,95%CI:0.48–0.93).DSME was superior to other models and traditional guidelines,suggesting a higher proportion of patients benefiting from surgery,especially breast-conserving *** debiased effect of patient characteristics,including age,tumor size,metastatic sites,lymph node status,and breast cancer subtypes,on surgery decision was also ***:Our findings suggested that DSME could effectively identify patients with MBC likely to benefit from surgery and the specific type of surgery *** method can facilitate the development of efficient,reliable treatment recommendation systems and provide quantifiable evidence for decision-making.

关键词： breast surgery causal inference deep learning metastatic breast cancer

Development laws of geological hazards along urban highway in SouthwestChina and countermeasures for prevention and control

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Geohazard Mechanics 2024年第1期2卷 13-20页

作者： Xu Gao China Academy of Railway Sciences Corporation limited BeijingChina

China is a mountainous country with highly developed road geologic hazards, which pose a great threat to theconstruction and operation of highways, bridges, and tunnels and to the safety of people and property. This paperdiscussed the types, basic features, formation, and prevention conditions of road geologic hazards in China basedon ﬁeld research and study data collected thus far. The study considered an urban area of a city in southwestChina as the center and a geological ﬁeld investigation was performed over a total of 282 km on three importantlifeline projects. The results show: Types of geologic hazards along the highways are mainly avalanches, debrisﬂows, and landslides, respectively. Among them, the landslips are mainly distributed along the roads, with slip,dumping, and wrong break types as the main ones;the debris ﬂows are widely distributed, mainly concentrated inthe river valleys;and the unstable slopes are relatively few in number. Geological disasters are characterized bylarge-scale and concentrated triggering in time and space, and a single disaster can easily trigger other disasters,thus forming a chain of disasters. Neotectonic movement, seismic activity, topography, climatic conditions,stratigraphic lithology, and human activities are important factors leading to geologic hazards in the study *** study is of great practical signiﬁcance for reducing the occurrence of roadbed diseases and prolonging theservice life of highways.

关键词： Urban highway Geologic hazards Development pattern Prevention