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Efflcient machining of a complex blisk channel using a disc cutter

Chinese Journal of Aeronautics 2024年第1期37卷 414-437页

作者： Xiangyu LI Zhaoyu LI dong he Junxue REN Qian feng Kai TANG Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong Kong 999077China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Xi’an Sanhang Power Technology Co. LtdXi’an 710000China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute FutianShenzhen 518057China HKUST Shenzhen Research Institute Shenzhen 518057China

For rough machining of a complex narrow cavity,e.g.,a complex blisk channel on an aero-engine,the typically used cutting tools are the slender cylindrical cutter and conical ***,as neither of the two is particularly suited for rough machining,wherein the main purpose is to remove a large volume as quickly as possible,the machining efficiency is low,especially when the part materials are of hard-to-cut types(e.g.,Titanium-alloy)for which it often takes days to rough machine a ***,disc machining provides a new and efficient roughing solution,since a disc cutter with a large radius enables a much larger cutting speed and thus a larger material removal ***,due to the large radius of the disc cutter,its potential collision with narrow and twisted channels becomes a serious *** this paper,we propose a novel twophase approach for efficiently machining a complex narrow cavity workpiece using a disc-shaped cutter,i.e.,3+2-axis disc-slotting of the channel by multiple layers(rough machining)+five-axis disc-milling of the freeform channel side surfaces(semi-finish machining).Both simulation and physical cutting experiments are conducted to assess the effectiveness and advantages of the proposed *** experimental results show that,with respect to a same cusp-height threshold on the channel side surfaces,the total machining time of the tested part by the proposed method is about only 36%of that by the conventional approach of plunging-milling(for roughing)plus milling by a slender cylindrical cutter(for semi-finishing).

关键词： Blisk channel CNC machining Disc cutter Roughing efficiency Tool path planning

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Increased glacier melt enhances future extreme floods in the southern Tibetan Plateau

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Advances in Climate Change Research 2024年第3期15卷 431-441页

作者： he SUN Tan-dong YAO feng-Ge SU Tinghai Ou Zhihua he Guoqiang TANG Deliang CheN State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden Centre for Hydrology University of SaskatchewanSaskatoon S7N 1K2Canada Climate and Global Dynamics National Center for Atmospheric ResearchBoulder CO 80307USA

Mountainous areas are of special hydrological concern because topography and atmospheric conditions can result in large and sudden floods,posing serious risks to water-related safety in neighbouring *** Yarlung Zangbo(YZ)River basin is the largest river basin on the Tibetan Plateau(TP),but how floods will discharge in this basin and how the role of glacier melt in floods will change throughout the 21st-century under shared socioeconomic pathways scenarios(SSP2-4.5 and SSP5-8.5)remain ***,we comprehensively address this scientific question based on a well-validated large-scale glacier-hydrology *** results indicate that extreme floods was projected to increase in the YZ basin,and was mainly reflected in increased duration(4–10 d per decade)and intensity(153–985 m^(3)s^(−1)per decade).Glacier runoff was projected to increase(2–30 mm per decade)throughout the 21st-century,but there was also a noticeable decrease or deceleration in glacier runoff growth in the late first half of the century under the SSP2-4.5,and in the latter half of the century under the *** melt was projected to enhance the duration(12%–23%)and intensity(15%–21%)of extreme floods under both SSPs,which would aggravate the impact of future floods on the socioeconomics of the YZ *** effect was gradually overwhelmed by precipitation-induced floods from glacier areas to YZ *** study takes the YZ basin as a projection framework example to help enrich the understanding of future flood hazards in basins affected by rainfall-or meltwater across the TP,and to help policy-makers and water managers develop future plans.

关键词： floods glacier Tibetan

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H-and J-aggregation of conjugated small molecules in organic solar cells

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Journal of Energy Chemistry 2024年第6期93卷 174-192,I0005页

作者： Qiaoqiao Zhao feng he State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353ShangdongChina Shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055GuangdongChina Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055GuangdongChina

As H-and J-aggregation receive more and more attention in the research of organic solar cells(OSCs),especially in small molecular systems,deep understanding of aggregation behavior is needed to guide the design of conjugated small molecular structure and the fabrication process of OSC *** this end,this review is ***,the review firstly introduced the basic information about H-and J-aggregation of conjugated small molecules in ***,the characteristics of H-and J-aggregation and the methods to identify them were ***,it reviewed the research progress of H-and J-aggregation of conjugated small molecules in OSCs,including the factors influencing H-and J-aggregation in thin film and the effects of H-and J-aggregation on OPV performance.

关键词： H-aggregation J-aggregation Organic solar cells Small molecules Efficiency Stability

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Endpoint temperature prediction of molten steel in RH using improved case-based reasoning

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1148-1154页

作者： Kai feng Hong-bing Wang An-jun Xu dong-feng he School of Metallurgy and Ecology Engineering University of Science and Technology Beijing State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Computer and Communication Engineering University of Science and Technology Beijing

An improved case-based reasoning （CBR） method was proposed to predict the endpoint temperature of molten steel in Ruhrstahl heraeus （RH） process. Firstly, production data were analyzed by multiple linear regressions and a pairwise comparison matrix in analytic hierarchy process （AHP） was determined by this linear regression＇s coefficient. The weights of various influencing factors were obtained by AHP. Secondly, the dividable principles of case base including ＂0-1＂ and ＂breakpoint＂ were proposed, and the case base was divided into several homogeneous parts. Finally, the improved CBR was compared with ordinary CBR, which is based on the even weight and the single base. The results show that the improved CBR has a higher hit rate for predicting the endpoint temperature of molten steel in RH.

关键词： steelmaking degassing case-based reasoning analytic hierarchy process temperature prediction

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CONVERGENCE ANALYSIS OF SOME FINITE ELEMENT PARALLEL ALGORITHMS FOR The STATIONARY INCOMPRESSIBLE MHD EQUATIONS

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Journal of Computational Mathematics 2024年第1期42卷 49-70页

作者： Xiaojing dong Yinnian he Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationSchool of Mathematics and Computational ScienceXiangtan UniversityXiangtan 411105China Institute of Applied Physics and Computational Mathematics Beijing 100088China School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China

By combination of iteration methods with the partition of unity method(PUM),some finite element parallel algorithms for the stationary incompressible magnetohydrodynamics(MHD)with different physical parameters are presented and *** algorithms are highly *** first,a global solution is obtained on a coarse grid for all approaches by one of the iteration *** parallelized residual schemes,local corrected solutions are calculated on finer meshes with overlapping *** subdomains can be achieved flexibly by a class of *** proposed algorithm is proved to be uniformly stable and ***,one numerical example is presented to confirm the theoretical findings.

关键词： Partition of unity method Local and parallel algorithm Finite element method Iteration methods Magnetohydrodynamics

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Meta-path reasoning of knowledge graph for commonsense question answering

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Frontiers of Computer Science 2024年第1期18卷 49-59页

作者： Miao ZHANG Tingting he Ming dong National Engineering Research Center for E-Learning Central China Normal UniversityWuhan 430079China Hubei Provincial Key Laboratory of Artificial Intelligence and Smart Learning Central China Normal UniversityWuhan 430079China National Language Resources Monitoring&Research Center for Network Media Central China Normal UniversityWuhan 430079China School of Computer Central China Normal UniversityWuhan 430079China

Commonsense question answering(CQA)requires understanding and reasoning over QA context and related commonsense knowledge,such as a structured Knowledge Graph(KG).Existing studies combine language models and graph neural networks to model ***,traditional knowledge graph are mostly concept-based,ignoring direct path evidence necessary for accurate *** this paper,we propose MRGNN(Meta-path Reasoning Graph Neural Network),a novel model that comprehensively captures sequential semantic information from concepts and *** MRGNN,meta-paths are introduced as direct inference evidence and an original graph neural network is adopted to aggregate features from both concepts and paths *** conduct sufficient experiments on the CommonsenceQA and OpenBookQA datasets,showing the effectiveness of ***,we conduct further ablation experiments and explain the reasoning behavior through the case study.

关键词： question answering knowledge graph graph neural network meta-path reasoning

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Energy partition in laser-induced cavitation bubbles near the rigid wall with a gas-containing hole

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Journal of Hydrodynamics 2024年第3期36卷 435-443页

作者： dong-qiao he Hai-gang Wen Si-yuan Geng Chen-xi Yang Qiang Zhong Zhi-feng Yao College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China PowerChina Beijing Engineering Corporation Limited Beijing100024China State Key Laboratory of Efficient Utilization of Agricultural Water Resources Beijing100083China Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing100083China

To investigate the energy partition in laser-induced cavitation bubbles near the rigid wall with a gas-containing hole,we utilized a nanosecond resolution photography system based on a Q-switched Nd:YAG laser and conventional industrial camera to carefully observe the transient process of bubble collapse near the rigid wall with a gas-containing *** analyzed the generation of collapse microjets and the emission of collapse shock *** found that the cavitation bubble near the rigid wall with a gas-containing hole collapsed at different times and space,and produced various types of shock *** on the far field pressure information of the shock waves measured by hydrophone,the energy of the shock waves generated by the bubble collapse near the rigid wall with a gas-containing hole is calculated for the first *** results show that the ratio of collapse shock wave energy to bubble energy is approximately between 0.7 and 0.8.

关键词： Energy partition bubble collapse laser-induced shock wave gas-containing hole

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Deep Insight of Design,Mechanism,and Cancer Theranostic Strategy of Nanozymes

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Nano-Micro Letters 2024年第2期16卷 165-217页

作者： Lu Yang Shuming dong Shili Gai Dan Yang he Ding Lili feng Guixin Yang Ziaur Rehman Piaoping Yang Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001People’s Republic of China Yantai Research Institute Harbin Engineering UniversityYantai 264000People’s Republic of China Key Laboratory of Green Chemical Engineering and Technology of heilongjiang Province College of Material Science and Chemical EngineeringHarbin University of Science and TechnologyHarbin 150040People’s Republic of China Department of Chemistry Quaid-i-Azam UniversityIslamabad 45320Pakistan

Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction conditions,good stability,and suitable for large-scale ***,with the cross fusion of nanomedicine and nanocatalysis,nanozyme-based theranostic strategies attract great attention,since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side ***,various nanozymes have been developed and used for tumor *** this review,more than 270 research articles are discussed systematically to present progress in the past five ***,the discovery and development of nanozymes are ***,classification and catalytic mechanism of nanozymes are ***,activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory,machine learning,biomimetic and chemical ***,synergistic theranostic strategy of nanozymes are ***,current challenges and future prospects of nanozymes used for tumor theranostic are outlined,including selectivity,biosafety,repeatability and stability,in-depth catalytic mechanism,predicting and evaluating activities.

关键词： Nanozymes Classification Prediction and design Catalytic mechanism Tumor theranostics

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Multiscale observation in wide-spatial radar surveillance based on coherent FDA design

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Science China(Information Sciences) 2024年第2期67卷 232-252页

作者： Lei YU feng he Yi SU College of Electronics Science National University of Defense Technology

Wide-spatial radar surveillance missions are challenging tasks, requiring an increased power budget and agility in transmission aimed at extracting information from multiple targets in different environments. These requirements necessitate high transmitting degrees of freedom(DOF) to achieve the objective of multiscale observation for specific tasks in specialized regions of interest. herein, we exploit the multiscale observation ability in wide-spatial radar surveillance based on frequency diverse array(FDA)radar. The proposed method facilitates spatial anisotropic control of multiple radar resources, including the transmitting waveforms, beampattern, and bandwidth. By utilizing a coherent FDA radar, we offer principles for the selection of baseband waveforms, in addition to the quantitative design of the beampattern gain and optimal bandwidth from the perspective of detection. The feasibility of the proposed method is validated through numerical experiments, thus indicating the potential in wide-spatial radar surveillance. Moreover,this work can be regarded as a preliminary attempt to gauge the efficacy of the computational array, a novel academic concept.

关键词： multi-scale observation wide-spatial surveillance frequency diverse array (FDA) beampattern synthesis frequency diversity gain computational array

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Carbonation Behavior Assessment of RH Slag Batch after Aqueous Extraction at Environmental Pressure

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Journal of Iron and Steel Research(International) 2014年第S1期21卷 74-81页

作者： An-jun XU Hui-ning ZHANG dong-feng he State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing School of Metallurgy and Chemical Engineering Jiangxi University of Science and Technology

In order to assess CO2 sequestration amount and carbonation degree for RH slag at surrounding pressure, carbonation process of RH slag batch in lab is investigated, and the parameters of carbonation degree and CO2 sequestration amount are the targets, and the relationship between both and relevant factors, such as CO2 flow, gas bubble size etc. is originally discussed. The carbonation degree increases when temperature increases before 60 oC, then decreases. Particle size has a positive effect on carbonation degree, and carbonation degree for 0.5 L/min is bigger than those for 0.1 L/min and 1.0 L/min. When small gas bubble generator is adopted, carbonation degree and CO2 sequestration amount is improved. The maximum carbonation degree and CO2 sequestration amount is 34% and 178.65 g/kgslag, respectively when 38 μm RH slag batch is carbonated for 90 min at 60 oC under the conditions that CO2 flow is 0.5 L/min and bubble size equals 5 mm. CaCO3 and MgCO3 phases exists through XRD analysis, showing that carbonation process is effective. Carbonation degree model is established assuming carbonation reaction occurs on the active surface of RH slag batch. This model fits very well by comparison between experimental results and model results.

关键词： RH slag carbonation degree CO2 bubble size CO2 sequestration amount

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