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Communications in Theoretical Physics 2024年第7期76卷 94-104页

作者： Zhang xin xu Wei School of Mathematics and Physics China University of GeosciencesWuhan 430074China

Recently,a dual relation T_(0)(n+1)=T_(HP)(n)between the minimum temperature(T_(0)(n+1))black hole phase and the Hawking-Page transition(T_(HP)(n))black hole phase in two successive dimensions was introduced by Wei et al(2.2. ***.D102.0411);this was reminiscent of the anti-de Sitter/conformal field theory(AdS/CFT)correspondence,as the Hawking-Page transition temperature could be treated as the temperature of the dual physical quantity on the boundary and the latter corresponds to that in the *** this paper,we discuss the Hawking-Page transition and the dual relations in Ads black holes surrounded by dark energy in general *** findings reveal the occurrence of the Hawking-Page transition between the thermal AdS radiation and thermodynamically stable large AdS black holes,in both the spacetime surrounded by phantom dark energy and the spacetime surrounded by quintessence dark *** discuss the effects of the phantom dark energy and quintessence dark energy on the Hawking-Page transition *** the dual relation in particular,it works well for the case of an AdS black holes surrounded by phantom dark *** the case of an Ads black hole surrounded by quintessence dark energy,the dual relation should be modified under an open assumption that the state parameter and the density parameter of the quintessence dark energy depend on the dimensions of the spacetime.

关键词： Hawking-Page transition dark energy black hole thermodynamics

Effect of hot isostatic pressure on the microstructure and tensile properties of γ'-strengthened superalloy fabricated through induction-assisted directed energy deposition

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International Journal of Minerals,Metallurgy 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 strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation 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 inhomogeneously distributed γ’ phases in interdendritic and dendritic core *** HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly *** further heat treatment(HT,1070℃,2.h + 845℃,2. 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 strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ ***,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.

关键词： directed energy deposition Ni-based superalloys high-temperature preheating hot isostatic pressing microstructure tensile properties

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 Zongben 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 greatly 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 good initial solution from the learned distribution so that the local search can find a high-quality *** develop two different deep network models to deal with DOPs established on set(the knapsack problem)and graph(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 given 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 graph ***,with sampled initial solutions,a classical genetic algorithm can achieve better solutions than a random initialized population in solving the maximum clique problems on DIMACS ***,we emphasize that the developed models can generalize in dimensions and across graphs with various densities,which is an important advantage on generalizing deep-learning-based optimization algorithms.

关键词： discrete optimization deep learning graph convolutional network local search

Heterometallic Mg-Ni-Mg Complex Promoted Hydrosilylation of Alkenes: Catalytic Performance and Intermediates Characterization

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Chinese Journal of Chemistry 2024年第18期42卷 2133-2139页

作者： Yanping Cai Shengjie Jiang xin xu Key Laboratory of Organic Synthesis of Jiangsu Province College of ChemistryChemical Engineering and Materials ScienceSoochowUniversitySuzhouJiangsu215123China

Background and Originality Content The catalytic hydrosilylation of unsaturated hydrocarbons,facilitated by transition metal(TM),is widely recognized as a proficient technique for the synthesis of high-value organosilicon compounds'ti-4l over the past few decades,the most dominant *** in hydrosilylation processes have been constituted by pre-Ccious metar complexesroceinerecent vears omore sustainabile earth-abundant metal catalysts have received increased attentionj2.14l The classcal mechanism of transition metal-catalyzed hydrosilylation is generally accomplished through a series of fundamental processes(Scheme 1a),including(i)coordination and oxidative addition of Si-H bond to a low-valent metal center to form e.g.,o-complex or silyl metal hydride;(ii)insertion of.C-C multipe bonds intometal-hdridelsior metal-silicon bond;jiol and(ii)reductive elimination that forwards the hydrosilylated product with Markovnikov or anti-Markovnikov selectivity.

关键词： Heterometallic complex Cooperative effect Hydrosilylation Magnesium Nickel hydride

A Rendezvous Mission to the Second Earth Trojan Asteroid 2.2. XL_5 with Low-Thrust Multi-Gravity 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, 2.2. 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 2.2. XL_(5) is ***, due to its high inclination and large eccentricity, direct impulsive transfer requires large amounts of fuel consumption. To address this challenge, we explore the benefits of electric propulsion and multi-gravity assist techniques for interplanetary missions. These two techniques are integrated in this mission design. The design of a low-thrust gravity-assist(LTGA) trajectory in multi-body dynamics is thoroughly investigated,which is a complex process. A comprehensive framework including three steps is presented here for optimization of LTGA trajectories in multi-body dynamics. The rendezvous mission to 2.2. XL_(5) is designed with this three-step approach. The most effective transfer sequence among the outcomes involves Earth–Venus–Earth–Venus-2.2. XL_(5). Numerical results indicate that the combination of electric propulsion and multi-gravity assists can greatly reduce the fuel consumption, with fuel consumption of 9.03%, making it a highly favorable choice for this rendezvous mission.

关键词： minor planets asteroids:general celestial mechanics Planetary Systems

Experimental Investigation on Vertical Hydraulic Transport of Ores in Deepsea Mining

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China Ocean Engineering 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 Engineering 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 Engineering 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 gradient of ore transport was evaluated with various particle size distributions,particle densities,feeding concentrations and mixture flow *** transport,the local concentration is larger 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 significantly to particle velocity and slip velocity,whereas the effect of the local concentration is marginal.A higher feeding concentration and mixture flow velocity result in an increased hydraulic *** effect of the particle size gradation is slight,whereas the particle density plays a crucial role in the transport.

关键词： deepsea mining vertical hydraulic transport experiment flow characteristics

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

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Genes & Diseases 2024年第5期11卷 98-101页

作者： xingchen Li xin xu Jianliu Wang Department of Obstetrics and Gynecology Peking University People’s HospitalBeijing 100044China Department of Obstetrics and Gynecology Beijing ChaoYang HospitalCapital Medical UniversityBeijing 100020China

Endometrial cancer(EC)is one of the most prominent malignancies in ***,despite these advancements in understanding EC pathogenesis,mortality rates have not *** force(TF)refers to endogenous mechanical forces exerted by cells.1 These forces act on the extracellular matrix and the extracellular tumor microenvironment through focal adhesions,thereby regulating cell proliferation and ***,the TF characteristics of endometrial cancer cells and their heterogeneity remain unclear.

关键词： endometrial metastasis endogenous

Optimization of Gas 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 Groundwater 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 energy,natural gas hydrate plays an important role in improving the global energy consumption *** the hydrate industry in the South China Sea is important to achieving‘carbon peak and carbon neutrality’goals 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 morphologies of hydrate-bearing sediments(HBSs)fluctuate *** key to numerically simulating HBS morphologies is the establishment of the conceptual model,which represents the objective and real description of the actual geological ***,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 huge 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 gas ***,the results show that the gas productivity of fluctuating HBSs was about 5%less than that of horizontal *** optimizing the depressurization amplitude,well length,and layout location of vertical wells,the productivity of fluctuating HBSs increased by about 56.6%.

关键词： natural gas hydrate numerical simulation fluctuation characteristics depressurization production production well optimization

Evolution of the rare earth trade network:A perspective of dependency and competition

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Geoscience Frontiers 2024年第3期15卷 183-191页

作者： Jilan xu Jiahao Li Vincent Charles xin Zhao School of Urban and Regional Science Shanghai University of Finance and EconomicsShanghai 200433China School of Business East China University of Science and TechnologyShanghai 200237China School of Management University of BradfordBradford BD71DPUnited Kingdom School of Statistics and Applied Mathematics Anhui University of Finance and EconomicsBengbu 233030China

As a global strategic reserve resource,rare earth has been widely used in important industries,such as military equipment and ***,existing analyses based solely on the total volume of rare earth trade fail to uncover the underlying competition and dependency *** address this gap,this paper employs the principles of trade preference and import similarity to construct dependency and competition *** network analysis is then employed to study the evolution of the global rare earth trade network from 2.02.to *** main conclusions are as *** global rare earth trade follows the Pareto principle,and the trade network shows a scale-free *** has emerged as the world’s largest importer and exporter of rare earth since *** the dependency network,China has become the most dependent country since *** result of community division shows that China has separated from the American community and formed new communities with the Association of Southeast Asian Nations(ASEAN)*** United States of America has formed a super-strong community with European and Asian *** the competition network,the distribution of competition intensity follows a scale-free *** countries face low-intensity competition,but there are numerous competing *** competition related to China has increased ***,the competition source for the United States of America has shifted from Mexico to China,resulting in China,the USA,and Japan becoming the core participants in the competition network.

关键词： Rare earth Trade network Dependency Competition Complex network analysis

Towards direct superlubricity and superlow wear via amino modification of polyhydroxy alcohol solutions

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Friction 2024年第9期12卷 1980-1990页

作者： Qiang MA Chengpeng YAN Rui YAN xin xu Haifeng WANG State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China Chongqing Innovation Center Northwestern Polytechnical UniversityChongqing 401135China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China

Friction remains as the primary mode of energy dissipation and components wear,and achieving superlubricity shows high promise in energy conservation and lifetime wear *** results in this work demonstrate that direct superlubricity combined with superlow wear can be realized for steel/Si_(3)N_(4)contacts on engineering scale when polyhydroxy alcohol solution was selectively modified by amino *** direct superlubricity occurs because 3-amino-1,2.propanediol molecules at the friction interface could be induced to rotate and adsorb vertically on the friction surface,forming in-situ thick and dense molecular films to passivate the asperity ***,amino modification is also conducive to improving the lubrication state from boundary to mixed lubrication regime by strengthening the intermolecular hydrogen bonding interaction,presenting enhanced load-bearing capability and reduced direct solid asperity ***,direct superlow average friction of 0.01 combined with superlow wear are achieved *** design principle of direct superlubricity and superlow wear in this work indeed offers an effective strategy to fundamentally improve energy efficiency and provide lifetime wear protection for moving mechanical assemblies.

关键词： direct superlubricity amino modification molecular layer superlow wear