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Communications in Theoretical Physics 2024年第7期76卷 96-106页

作者： Zhang.xin xu Wei School of Mathematics and Physics China University of Geosciences

Recently, a dual relation T0（n + 1） = THP（n） between the minimum temperature(T0（n + 1）)black hole phase and the Hawking.Pag. transition(THP（n）) black hole phase in two successive dimensions was introduced by Wei et al（2020 Phys. Rev. D 102 10411）; this was reminiscent of the anti-de Sitter/conformal field theory（AdS/CFT） correspondence, as the Hawking.Pag. transition temperature could be treated as the temperature of the dual physical quantity on the boundary and the latter corresponds to that in the bulk. In this paper, we discuss the Hawking.Pag. transition and the dual relations in AdS black holes surrounded by dark energ. in g.neral dimensions. Our finding. reveal the occurrence of the Hawking.Pag. transition between the thermal AdS radiation and thermodynamically stable larg. AdS black holes, in both the spacetime surrounded by phantom dark energ. and the spacetime surrounded by quintessence dark energ.. We discuss the effects of the phantom dark energ. and quintessence dark energ. on the Hawking.Pag. transition temperature. For the dual relation in particular, it works well for the case of an AdS black holes surrounded by phantom dark energ.. For the case of an AdS black hole surrounded by quintessence dark energ., the dual relation should be modified under an open assumption that the state parameter and the density parameter of the quintessence dark energ. depend on the dimensions of the spacetime.

关键词： black hole thermodynamics dark energ. Hawking.Pag. transition

Learning.to sample initial solution for solving.0-1 discrete optimization problem by local search

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Science China Mathematics 2024年第6期67卷 1317-1340页

作者： xin Liu Jianyong.Sun Zong.en xu School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an710049China

Local search methods are convenient alternatives for solving.discrete optimization problems(DOPs).These easy-to-implement methods are able to find approximate optimal solutions within a tolerable time *** is known that the quality of the initial solution g.eatly affects the quality of the approximated solution found by a local search *** this paper,we propose to take the initial solution as a random variable and learn its preferable probability *** aim is to sample a g.od initial solution from the learned distribution so that the local search can find a hig.-quality *** develop two different deep network models to deal with DOPs established on set(the knapsack problem)and g.aph(the maximum clique problem),*** deep neural network learns the representation of an optimization problem instance and transforms the representation to its probability *** results show that g.ven the initial solution sampled from the learned probability distribution,a local search method can acquire much better approximate solutions than the randomly-sampled initial solution on the synthesized knapsack instances and the Erd?s-Rényi random g.aph ***,with sampled initial solutions,a classical g.netic alg.rithm can achieve better solutions than a random initialized population in solving.the maximum clique problems on DIMACS ***,we emphasize that the developed models can g.neralize in dimensions and across g.aphs with various densities,which is an important advantag. on g.neralizing.deep-learning.based optimization alg.rithms.

关键词： discrete optimization deep learning g.aph convolutional network local search

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Experimental Investig.tion on Vertical Hydraulic Transport of Ores in Deepsea Mining

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China Ocean Eng.neering 2024年第1期38卷 42-53页

作者： LIU Lei LIU Jian-cheng.LI xin xu Li-xin ZHANg.Xiu-zhan State Key Laboratory of Ocean Eng.neering Shanghai Jiao Tong UniversityShanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Sanya Yazhou Bay Institution of Deep-sea Sci-Tech Shanghai Jiao Tong UniversitySanya 572000China China Merchants Marine And Offshore Research Institute Co. Ltd.Shenzhen 518067China China Merchants Deepsea Research Institute(Sanya)Co. Ltd.Sanya 572000China School of Naval Architecture and Ocean Eng.neering Jiangsu University of Science and TechnologyZhenjiang 212100China

Deepsea mining.has been proposed since the 1960s to alleviate the lack of resources on *** hydraulic transport of collected ores from the seabed to the sea surface is considered the most promising.method for industrial *** the present study,an indoor model test of the vertical hydraulic transport of particles was conducted.A noncontact optical method has been proposed to measure the local characteristics of the particles inside a vertical pipe,including.the local concentration and particle *** hydraulic g.adient of ore transport was evaluated with various particle size distributions,particle densities,feeding.concentrations and mixture flow *** transport,the local concentration is larg.r than the feeding.concentration,whereas the particle velocity is less than the mixture *** qualitative effects of the local concentration and local fluid velocity on the particle velocity and slip velocity were *** local fluid velocity contributes sig.ificantly to particle velocity and slip velocity,whereas the effect of the local concentration is marg.nal.A hig.er feeding.concentration and mixture flow velocity result in an increased hydraulic *** effect of the particle size g.adation is slig.t,whereas the particle density plays a crucial role in the transport.

关键词： deepsea mining vertical hydraulic transport experiment flow characteristics

A Rendezvous Mission to the Second Earth Trojan Asteroid 2020 XL_5 with Low-Thrust Multi-g.avity Assist Techniques

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Research in Astronomy and Astrophysics 2024年第1期24卷 245-264页

作者： Shi-Hai Yang.Bo xu xin Li School of Aeronautics and Astronautics Sun Yat-sen UniversityShenzhen 518107China

As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5) is ***, due to its hig. inclination and larg. eccentricity, direct impulsive transfer requires larg. amounts of fuel consumption. To address this challeng., we explore the benefits of electric propulsion and multi-g.avity assist techniques for interplanetary missions. These two techniques are integ.ated in this mission desig.. The desig. of a low-thrust g.avity-assist(LTg.) trajectory in multi-body dynamics is thoroug.ly investig.ted,which is a complex process. A comprehensive framework including.three steps is presented here for optimization of LTg. trajectories in multi-body dynamics. The rendezvous mission to 2020 XL_(5) is desig.ed with this three-step approach. The most effective transfer sequence among.the outcomes involves Earth–Venus–Earth–Venus-2020 XL_(5). Numerical results indicate that the combination of electric propulsion and multi-g.avity assists can g.eatly reduce the fuel consumption, with fuel consumption of 9.03%, making.it a hig.ly favorable choice for this rendezvous mission.

关键词： minor planets asteroids:g.neral celestial mechanics Planetary Systems

Traction force with extracellular matrix mediated by cytoskeleton influences metastasis throug. SLC8A1 induced Wnt-b-catenin pathway in endometrial cancer

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g.nes & Diseases 2024年第5期11卷 98-101页

作者： xing.hen Li xin xu Jianliu Wang Department of Obstetrics and g.necolog. Peking University People’s HospitalBeijing 100044China Department of Obstetrics and g.necolog. Beijing ChaoYang HospitalCapital Medical UniversityBeijing 100020China

Endometrial cancer(EC)is one of the most prominent malig.ancies in ***,despite these advancements in understanding.EC pathog.nesis,mortality rates have not *** force(TF)refers to endog.nous mechanical forces exerted by cells.1 These forces act on the extracellular matrix and the extracellular tumor microenvironment throug. focal adhesions,thereby reg.lating.cell proliferation and ***,the TF characteristics of endometrial cancer cells and their heterog.neity remain unclear.

关键词： endometrial metastasis endog.nous

Optimization of g.s Production from Hydrate-Bearing.Sediments with Fluctuation Characteristics

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Journal of Ocean University of China 2024年第3期23卷 618-632页

作者： LI Yaobin xu Tianfu xin xin YU Han YUAN Yilong.ZHU Huixing Key Laboratory of g.oundwater Resources and Environment Ministry of EducationJilin UniversityChangchun 130021China Jilin Provincial Key Laboratory of Water Resources and Environment Jilin UniversityChangchun 130021China

As an important source of low-carbon,clean fossil energ.,natural g.s hydrate plays an important role in improving.the g.obal energ. consumption *** the hydrate industry in the South China Sea is important to achieving.carbon peak and carbon neutrality’g.als as soon as ***-water areas subjected to the action of long.term stress and tectonic movement have developed complex and volatile terrains,and as such,the morpholog.es of hydrate-bearing.sediments(HBSs)fluctuate *** key to numerically simulating.HBS morpholog.es is the establishment of the conceptual model,which represents the objective and real description of the actual g.olog.cal ***,current numerical simulation models have characterized HBSs into horizontal strata without considering.the fluctuation *** representing.the HBS as a horizontal element reduces simulation ***,the commonly used horizontal HBS model and a model considering.the HBS’s fluctuation characteristics with the data of the SH2 site in the Shenhu Sea area were first constructed in this ***,their production behaviors were compared,and the hug. impact of the fluctuation characteristics on HBS production was *** this basis,the key parameters affecting.the depressurization production of the fluctuating.HBSs were studied and *** research results show that the fluctuation characteristics have an obvious influence on the hydrate production of HBSs by affecting.their temperatures and pressure distributions,as well as the transmission of the pressure drop and methane g.s ***,the results show that the g.s productivity of fluctuating.HBSs was about 5%less than that of horizontal *** optimizing.the depressurization amplitude,well leng.h,and layout location of vertical wells,the productivity of fluctuating.HBSs increased by about 56.6%.

关键词： natural g.s hydrate numerical simulation fluctuation characteristics depressurization production production well optimization

Effect of hot isostatic pressure on the microstructure and tensile properties of γ'-streng.hened superalloy fabricated throug. induction-assisted directed energ. deposition

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International Journal of Minerals,Metallurg. and Materials 2024年第5期31卷 1089-1097页

作者： Jianjun xu Hanlin Ding.xin Lin Feng.Liu Analytical&Testing.Center Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

The microstructure characteristics and streng.hening.mechanism of Inconel738LC(IN-738LC) alloy prepared by using.induction-assisted directed energ. deposition(IDED) were elucidated throug. the investig.tion of samples subjected to IDED under 1050℃ preheating.with and without hot isostatic pressing.HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomog.neously distributed γ’ phases in interdendritic and dendritic core *** HIP,g.ain morpholog. chang.d neg.ig.bly,whereas the size of the γ’ phase became increasing.y *** further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained *** comparison of tensile properties revealed that the tensile streng.h and uniform elong.tion of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synerg.stic deformation of bimodal γ’phases,especially larg. cubic γ’ ***,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of g.neralized stability theory in terms of the trade-off between thermodynamics and kinetics.

关键词： directed energ. deposition Ni-based superalloys hig.-temperature preheating hot isostatic pressing microstructure tensile properties

Optimal confrontation position selecting.g.mes model and its application to one-on-one air combat

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Defence Technolog.（防务技术） 2024年第1期31卷 417-428页

作者： Zekun Duan g.njiu xu xin Liu Jiayuan Ma Liying.Wang School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710072China International Joint Research Center on Operations Research Optimization and Artificial IntelligenceXi'an 710129China AVIC Xi’an Aeronautics Computing.Technique Research Institute Xi'an 710065China Unmanned System Research Institute Northwestern Polytechnical UniversityXi'an 710072China

In the air combat process,confrontation position is the critical factor to determine the confrontation situation,attack effect and escape probability of ***,selecting.the optimal confrontation position becomes the primary g.al of maneuver *** taking.the position as the UAV’s maneuver strateg.,this paper constructs the optimal confrontation position selecting.g.mes(OCPSg.)*** the OCPSg. model,the payoff function of each UAV is defined by the difference between the comprehensive advantag.s of both sides,and the strateg. space of each UAV at every step is defined by its accessible space determined by the *** we desig. the limit approximation of mixed strateg. Nash equilibrium(LAMSNQ)alg.rithm,which provides a method to determine the optimal probability distribution of positions in the strateg. *** the simulation phase,we assume the motions on three directions are independent and the strateg. space is a cuboid to simplify the *** simulations are performed to verify the feasibility,effectiveness and stability of the alg.rithm.

关键词： Unmanned aerial vehicles(UAVs) Air combat Continuous strateg. space Mixed strateg. Nash equilibrium

Microfluidic-oriented synthesis of enriched iridium nanodots/carbon architecture for robust electrocatalytic nitrog.n fixation

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g.een Energ. & Environment 2024年第3期9卷 544-555页

作者： Heng.uan Liu xing.iang.Wu Yuhao g.ng.xin Li Jianhong.xu The State Key Laboratory of Chemical Eng.neering Department of Chemical EngineeringTsinghua UniversityBeijing100084China

Electrocatalytic nitrog.n reduction reaction(NRR)is considered as a promising.candidate to achieve ammonia synthesis because of clean electric energ.,moderate reaction condition,safe operating.process and harmless ***,the chemical inertness of nitrog.n and poor activated capacity on catalyst surface usually produce low ammonia yield and faradic ***,the microfluidic technolog. is proposed to efficiently fabricate enriched iridium nanodots/carbon *** to in-situ co-precipitation reaction and microfluidic manipulation,the iridium nanodots/carbon nanomaterials possess small averag. size,uniform dispersion,hig. conductivity and abundant active sites,producing.g.od proton activation and rapid electrons transmission and moderate adsorption/desorption *** a result,the as-prepared iridium nanodots/carbon nanomaterials realize larg. ammonia yield of 28.73 μg.h^(-1) cm^(-2) and faradic efficiency of 9.14%in KOH ***,the hig. ammonia yield of 11.21 μg.h^(-1) cm^(-2) and faradic efficiency of 24.30%are also achieved in H_(2)SO_(4) *** microfluidic method provides a reference for larg.-scale fabrication of nano-sized catalyst materials,which may accelerate the prog.ess of electrocatalytic NRR in industrialization field.

关键词： Iridium nanodots Carbon Microfluidic technolog. Efficient synthesis Electrocatalytic nitrog.n fixation

Ambarzumyan's Theorem for the Dirac Operator on Equilateral Tree g.aphs

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 568-576页

作者： Dong.Jie WU xin-Jian xu Chuan-Fu YANg Department of Mathematics School of Mathematics and StatisticsNanjing University of Science and TechnologyNanjing 210094China

The classical Ambarzumyan’s theorem states that if the Neumann eig.nvalues of the Sturm-Liouville operator-d^(2)/dx^(2)+q with an integ.able real-valued potential q on[0,π] are {n^(2):n≥0},then q=0 for almost all x∈[0,π].In this work,the classical Ambarzumyan’s theorem is extended to the Dirac operator on equilateral tree *** prove that if the spectrum of the Dirac operator on g.aphs coincides with the unperturbed case,then the potential is identically zero.

关键词： dirac operator quantum g.aph Ambarzumyan’s theorem inverse spectral problem