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Microstructure and property of laser additive manufactured alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si after aged at different temperatures

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Rare Metals 2024年第5期43卷 2275-2281页

作者： Guo-Chao Li Xu Cheng hua-Ming wang National Engineering Laboratory of Additive Manufacturing for Large Metallic Components and Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for Large Metallic Components School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The solid solution and aging treatment for conventional manufacturing processes might not be suitable for laser additive manufactured titanium alloys due to the different lamellar *** this study,the influence of aging temperatures(600,700 and 800°C)on microstructure and mechanical properties of titanium alloy Ti-6Al-2V-1.5Mo-0.5Zr-0.3Si was *** results indicate that after solid solution treatment at 970°C followed by water quenching,the alloy mainly consists of coarsening lamellar a phase in martensite α' *** at 600°C will not change the size of primary lamellar α phase but lead to huge amount of secondary a phases(α_(s))generating with very fine *** increasing the aging temperature,the number of α_(s) decreases but with coarsened *** aged at 800°C,the width of the asphase reaches 350 nm,almost 7 times wider than that aged at 600°*** changing size of α_(s) obviously influences the property of the *** fine α_(s) leads to high strength and microhardness but low plasticity,and specimen aged at 700°C with suitable assize has the best comprehensive properties.

关键词： α+βtitanium alloy Laser additive manufacturing Solid solution and aging treatment Microstructure Room temperature tensile property

Stochastic Flexibility Evaluation for Virtual Power Plants by Aggregating Distributed Energy Resources

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 988-999页

作者： Siyuan wang Wenchuan Wu Qizhan Chen Junjie Yu peng wang Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Zhongshan Power Supply Bureau of the Guangdong Power Grid Corporation Zhongshan 528400China Beijing Qingda Gaoke System Control Company Beijing 102208China CSEE IEEE

To manage a large amount of flexible distributed energy resources(DERs)in the distribution networks,the virtual power plant(VPP)is introduced into the *** VPP can optimally dispatch these resources in a cluster manner and provide flexibility for the power system operation as a *** existing studies formulate the equivalent power flexibility of the aggregating DERs as deterministic optimization models without considering their *** this paper,we introduce the stochastic power flexibility range(PFR)and timecoupling flexibility(TCF)to describe the power flexibility of *** this model,both operational constraints and the randomness of the DERs’output are incorporated,and a combined model and data-driven solution is proposed to obtain the stochastic PFR,TCF,and cost function of *** aggregating model can be easily incorporated into the optimization model for the power system operator or market bidding,considering ***,a numerical test is *** results show that the proposed model not only has higher computational efficiency than the scenario-based methods but also achieves more economic benefits.

关键词： Chance constrained optimization combined model and data-driven stochastic power flexibility virtual power plant

Assessment of piloting behavior impact on landing risk of transport aircraft

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Chinese Journal of Aeronautics 2024年第9期37卷 178-192页

作者： Zhiyue XIONG Shuguang ZHANG Mingkai wang peng TANG Mengmeng wang School of Transportation Science and Engineering Beihang UniversityBeijing 102206China

The human factors and their interaction with other factors play an important role in the flight safety of transport *** this paper,a paradigm of risk assessment for transport aircraft interacting with piloting behaviors is proposed,with focus on landing which is the most accident-prone flight stage in aviation safety ***-based flight simulation serves as our data source for landing risk analysis under uncertainties.A digital pilot in the loop that reflects the human piloting behaviors is employed to facilitate simulation *** types of unsafe events in landing are identified from *** this basis,the landing safety boundary is extracted via stochastic simulation to divide safety and hazardous flight status domains,which con-tributes to flight status management and risk *** simulation results indicate that appro-priate piloting behavior,which is active response and fast target acquisition with minimum overshoot and fluctuation,shows benefit to landing *** subset simulation technique is employed to further refine the boundary with less computational ***,the effect of airspeed,windspeed,and other factors on landing risk is also *** proposed risk assess-ment method would help optimize operation procedure and develop targeted pilot training program.

关键词： Landing risk assessment Risk parameterization Human factors Piloting behavior model Landing safety boundary Subset simulation

Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery

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Petroleum Science 2024年第2期21卷 974-986页

作者： Xi-Dao Wu peng Xiao Bei Liu Guang-Jin Chen Jian-hua Pang State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Ocean Intelligence Technology Center Shenzhen Institute of Guangdong Ocean UniversityShenzhen518120GuangdongChina

CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility ***,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely *** this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil ***,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT ***,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary ***,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were *** results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) *** inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was ***_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water ***,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,*** work may provide guidelines for EOR using CO_(2) emulsions with high water cut.

关键词： CO_(2)/H_(2)O emulsion High water cut CO_(2) mobility control Enhanced oil recovery

In situ Simulation of Thermal Reality

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Research 2024年第2期2023卷 685-690页

作者： peng Jin Jinrong Liu Fubao Yang Fabio Marchesoni Jian-hua Jiang Jiping huang Department of Physics State Key Laboratory of Surface Physicsand Key Laboratory of Micro and Nano Photonic Structures(MOE)Fudan UniversityShanghai 200438China Center for Phononics and Thermal Energy Science Shanghai Key Laboratory of Special Artificial Microstructure Materials and TechnologySchool of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics University of CamerinoCamerino 62032Italy Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China

Simulated reality encompasses virtual,augmented,and mixed realities梕ach characterized by different degrees of truthfulness in the visual perception:"all false","coexistence of true and false,"and"difficult distinction between true and false,"*** all these technologies,however,the temperature rendering of virtual objects is still an unsolved ***,the lack of thermal tactile functions substantially reduces the quality of the user's real-experience *** address this challenge,we propose theoretically and realize experimentally a technological platform for the in situ simulation of thermal *** this purpose,we design a thermal metadevice consisting of a reconfigurable array of radiating units,capable of generating the thermal image of any virtual object,and thus rendering it in situ together with its thermal *** is a substantial technological advance,which opens up new possibilities for simulated reality and its applications to human activities.

关键词： false rendering signature

A new insight into LPSO phase transformation and mechanical properties uniformity of large-scale Mg-Gd-Y-Zn-Zr alloy prepared by multi-pass friction stir processing

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Journal of Magnesium and Alloys 2024年第5期12卷 2041-2056页

作者： Xiaohu Guan Wen wang Ting Zhang Pai peng Qiang Liu peng Han Ke Qiao Jun Cai Liqiang wang Kuaishe wang School of Metallurgical Engineering National and Local Joint Engineering Research Center for Functional Materials ProcessingXi’an University of Architecture and TechnologyNo.13 Yanta RoadXi’anShaanxi 710055China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China State Key Laboratory of Metal Matrix Composites School of Material Science and EngineeringShanghai Jiao Tong UniversityNo.800 Dongchuan RoadShanghai 200240China

A large-scale fine-grained Mg-Gd-Y-Zn-Zr alloy plate with high strength and ductility was successfully prepared by multi-pass friction stir processing(MFSP)technology in this *** structure of grains and long period stacking ordered(LPSO)phase were characterized,and the mechanical properties uniformity was ***,a quantitative relationship between the microstructure and tensile yield strength was *** results showed that the grains in the processed zone(PZ)and interfacial zone(IZ)were refined from 50μm to 3μm and 4μm,respectively,and numerous original LPSO phases were *** IZ,some block-shaped 18R LPSO phases were transformed into needle-like 14H LPSO phases due to stacking faults and the short-range diffusion of solute *** severe shear deformation in the form of kinetic energy caused profuse stacking fault to be generated and move rapidly,greatly increasing the transformation rate of LPSO *** MFSP,the ultimate tensile strength,yield strength and elongation to failure of the large-scale plate were 367 MPa,305 MPa and 18.0% *** refinement and LPSO phase strengthening were the major strengthening mechanisms for the MFSP *** particularly,the strength of IZ was comparable to that of PZ because the strength contribution of the 14H LPSO phase offsets the lack of grain refinement strengthening in *** result opposes the widely accepted notion that IZ is a weak region in MFSP-prepared large-scale fine-grained plate.

关键词： Friction stir processing Multi-pass Mg-Gd-Y-Zn-Zr alloy LPSO phase transformation Mechanical properties

The Sequential Pricing of Ride-Hailing System with Rental Service in the Context of Fleet Electrification

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 77-105页

作者： Yaoyao Ku peng Wu Qiang Ren Yiqing wang Business School Sichuan UniversityChengdu610065China

Surging demand and reduced capacity in the ride-hailing industry have prompted numerous ride-hailing platforms to build their own car-rental services catering to drivers who do not possess private vehicles. However, the trade-off between the ride-hailing service and the car-rental service is an important issue that is still unclear in theory. Moreover, ride-hailing platforms are transitioning towards all-electric fleets in the context of Carbon Neutrality goals and government regulations. This paper considers a ride-hailing system comprising a monopolist ride-hailing platform, an electric vehicle (EV) rental firm, and a gasoline vehicle (GV) rental firm. Furthermore, we build a stylized model to study the sequential pricing of the system. The equilibrium outcomes show the significant impact of the ride-hailing platform’s decision to continue or withdraw offering EV rental services on EV and GV drivers’ net earnings, rental prices, and wages. The ride-hailing platform providing EV rental services increases EV drivers’ net earnings but decreases the GV driver wages and rental prices. However, the EV rental service offered by the ride-hailing platform does not necessarily lead to an increased total profit for the system. The improved profitability of the system by the ride-hailing platform providing EV rental services is contingent upon lower rider prices and higher fuel costs. The ride-hailing platform’s EV rental services provision also effectively fosters the ride-hailing fleet’s electrification. Furthermore, as the number of riders increases, the ride-hailing platform should reduce the commission rate for EV drivers to maintain competitiveness and profitability.

关键词： Ride-hailing system car rental fleet electrification sequential pricing differential wage scheme

A self-organization formation configuration based assignment probability and collision detection

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Journal of Systems Engineering and Electronics 2024年第1期35卷 222-232页

作者： SONG Wei wang Tong YANG Guangxin ZHANG peng School of Harbin Engineering University Harbin 150001China Chinese Aeronautical Establishment Beijing 100010China

The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research *** on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment probability is proposed to achieve the shortest overall formation path of multi-UAVs with low complexity and reduce the energy *** order to avoid the collision between UAVs in the formation process,the concept of safety ball is introduced,and the collision detection based on continuous motion of two time slots and the lane occupation detection after motion is proposed to avoid collision between *** on the idea of game theory,a method of UAV motion form setting based on the maximization of interests is proposed,including the maximization of self-interest and the maximization of formation interest is proposed,so that multi-UAVs can complete the formation task quickly and reasonably with the linear trajectory assigned in ***,through simulation verification,the multi-UAVs target assignment algorithm based on the assignment probability proposed in this paper can effectively reduce the total path length,and the UAV motion selection method based on the maximization interests can effectively complete the task formation.

关键词： straight line trajectory assignment probability collision detection lane occupation detection maximization of interests

Coupled funnel control for supersonic tailless aerial vehicle on penetrating counter air

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Chinese Journal of Aeronautics 2024年第7期37卷 458-481页

作者： Yingyang wang peng ZHANG Jilian GUO Jianbo HU Equipment Management and Unmanned Aerial Vehicle Engineering School Air Force Engineering UniversityXi’an 710051China Aviation Engineering School Air Force Engineering UniversityXi’an 710038China

Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control *** attack angle and the sideslip angle need to be limited to ensure that the engine inlet and the aerodynamic rudder at the rear of the vehicle can work properly,which is the so-called security *** addition,the tracking error of the aerodynamic angle needs to be limited to achieve effective attitude control or high-accuracy tracking of trajectories,which is the so-called performance *** this end,an attitude control method that meets the needs of PCA has been devised,based on constraint definition,coupled constraints handling,and control law ***,mathematical descriptions of the security constraints,performance constraints,and control constraints are ***,two treatment methods,coupled command filter and coupled funnel control are proposed for the aerodynamic angle coupled constraint ***,based on Nonlinear Dynamic Inverse(NDI)design,the coupled funnel controller is designed and validated by simulation for two typical mission scenarios,high-altitude penetration and low-altitude surprise *** proposed control method not only satisfies the security and performance constraints of STAV attitude control but also is highly robust.

关键词： Supersonic tailless aircraft Penetrating counter air Funnel control Attitude control Control allocation