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OptoGPT: A foundation model for inverse design in optical multilayer thin film structures

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Opto-Electronic Advances 2024年第7期7卷 4-16页

作者： Taigao ma Haozhu Wang l.Jay Guo department of Physics University of MichiganAnn ArborMichigan 48109USA department of Electrical Engineering and Computer Science University of MichiganAnn ArborMichigan 48109USA

Optical multilayer thin film structures have been widely used in numerous photonic ***,existing inverse design methods have many drawbacks because they either fail to quickly adapt to different design targets,or are difficult to suit for different types of structures,e.g.,designing for different materials at each *** methods also cannot accommodate versatile design situations under different angles and *** addition,how to benefit practical fabrications and manufacturing has not been extensively considered *** this work,we introduce OptoGPT(Opto Generative Pretrained Transformer),a decoder-only transformer,to solve all these drawbacks and issues simultaneously.

关键词： multilayer thin film structure inverse design foundation models deep learning structural color

Guaranteed Cost Attitude Tracking Control for Uncertain Quadrotor Unmanned Aerial Vehicle Under Safety Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1447-1457页

作者： Qian ma Peng Jin Frank l.lewis School of Automation Nanjing University of Science and TechnologyNanjing 210094China UTA Research Institute University of Texas at ArlingtonFort WorthTexas 76118 USA IEEE

In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is ***,an augmented system is constructed by the tracking error system and reference *** transformation aims to convert the tracking control prob-lem into a stabilization control ***,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty *** on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is ***,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal *** proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety *** performance of the algorithm is evaluated by the numerical simulation.

关键词： Attitude tracking control quadrotor unmanned aerial vehicle(QUAV) reinforcement learning safety constraints uncertain disturbances.

Improved Reall-Santos method for AdS black holes in general 4-derivative gravities

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 74-86页

作者： Peng-Ju Hu liang ma Hong lü Yi Pang Center for Joint Quantum Studies and department of Physics School of ScienceTianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Peng Huanwu Center for Fundamental Theory Hefei 230026China

For asymptotically flat black holes,Reall-Santos method is a convenient tool to compute leading higher derivative corrections to the thermodynamic quantities without actually solving the modified field ***,there are subtleties in its generalization to asymptotically AdS black holes with general higher derivative *** of all,it is necessary to know all the higher derivative holographic counterterms and the surface terms implementing the variational principle and subtracting the *** then needs to solve for the modified AdS radius and rescale the time coordinate in an appropriate way such that the induced metric on the conformal boundary of AdS black hole is not *** observe that Reall-Santos method can be directly applied to a particular 4-derivative gravity model,known as the Einstein-Weyl gravity,which does not modify the AdS radius and requires only the Gibbons-Hawking-York term and holographic counterterms for the 2-derivative *** thus suggest that to compute the thermodynamic quantities of AdS black holes in general 4-derivative theories of gravity,one simply needs to transform it to a Einstein-Weyl gravity with identical thermodynamic variables by appropriate field *** explicitly verify this proposal with spherically-symmetric and static charged black holes in Einstein-maxwell theory extended with generic 4-derivative interactions.

关键词： black holes thermodynamics higher-derivative corrections effective theories higher dimensional black holes quantum gravity

The Influence of limestone Powder and Metakaolin Co-Blending on the Hydration Process and Mechanical Properties of Q-Phase Cement

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Journal of Wuhan University of Technology(materials Science) 2024年第5期39卷 1169-1176页

作者： XIONG Xuan HE Yongjia lÜlinnü ma Jie WANG Fazhou State Key laboratory of Silicate materials for Architectures Wuhan University of TechnologyWuhan 430070China School of materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key laboratory of Theory and Application of Advanced materials Mechanics School of ScienceWuhan University of TechnologyWuhan 430070China China Railway design Corporation Tianjin 300250China

A ternary system comprising Ca_(20)Al_(26)Mg_(3)Si_(3)O_(68)(Q-phase),limestone,and metakaolin is proposed,and its hydration behavior,hydration product phases,microstructure,and mechanical properties are investigated and compared with pure Q-phase *** results indicate that the ternary system exhibits exceptional and sustained compressive strength even under a 40℃environment,significantly outperforming pure *** mechanism lies in that metakaolin effectively inhibits the transformation of metastable ***,the interactions among Q-phase,limestone,and metakaolin further enhance the cementitious *** ternary system effectively addresses potential issues of strength loss in Q-phase cement application,and as a low-carbon cementitious material system,it holds promising potential applications.

关键词： Q-phase limestone metakaolin hydration compressive strength

Electrode particulate materials for advanced rechargeable batteries:A review

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Particuology 2024年第3期86卷 160-181页

作者： Mingyang ma Miao du Yan liu Hongyan lü Jialin Yang Zelin Hao Jinzhi Guo Xinglong Wu MOE Key laboratory for UV light-Emitting materials and Technology Northeast Normal UniversityChangchunJilin130024China department of Chemistry Northeast Normal UniversityChangchunJilin130024China

The demand for large-scale energy storage is increasing due to the decreasing non-renewable resources and deteriorating environmental *** rechargeable batteries with high energy density and long cycle performance is an ideal choice to meet the demand of energy storage *** development of excellent electrode particles is of great significance in the commercialization of nextgeneration *** ideal electrode particles should balance raw material reserves,electrochemical performance,price and environmental *** them,the development of electrode particulate materials with excellent electrochemical properties is the top priority at *** this review,the typical researches of electrode materials are summarized in terms of crystal structure,morphology,pore structure,surface and interface ***,the structural characteristics and improvement methods of transition metal oxides,polyanionic compounds,Prussian blue and their analogues are ***,the different effects of particulate morphology,pore,surface and interface structure on the performance of electrode materials are *** designing high-performance electrode materials,preparation route should be set according to the particle properties of the materials and the synergistic effect of various optimization methods should be *** the same time,in addition to the electrode materials,other components of the rechargeable batteries,such as current collector,separator and electrolytes,should be optimized to improve the overall performance of the *** review would provide important guiding principle for designing high-performance electrode particulate materials.

关键词： Particulate properties Electrode materials Rechargeable batteries

Uniform decomposition of velocity gradient tensor

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Journal of Hydrodynamics 2024年第1期36卷 24-34页

作者： Chenxi ma Chaoqun liu department of mathematics University of Texas at ArlingtonArlingtonTXUSA

In this paper,the principal decomposition of the velocity gradient tensor[∇v]is discussed in 3 cases based on the discriminant∆:∆0 with 3 distinct real eigen values,and∆=0 with 1 or 2 distinct real eigen *** velocity ... 详细信息

In this paper,the principal decomposition of the velocity gradient tensor[∇v]is discussed in 3 cases based on the discriminant∆:∆l eigen value and a pair of conjugate complex eigen values,∆>0 with 3 distinct real eigen values,and∆=0 with 1 or 2 distinct real eigen *** velocity gradient tensor can also be classified as rotation point,which can be decomposed into three parts,i.e.,rotation[R],shear[S]and stretching/compression[SC],and non-rotation point,we defined a new resistance term[l],and the tensor can be decomposed into three parts,i.e.,resistance[l],shear[S]and stretching/compression[SC].Example matric are also displayed to demonstrate the new *** of principal decomposition between 3 different cases,and between Resistance and liutex will also be discussed.

关键词： Velocity gradient liutex resistance fluid kinematics

CToMP: a cycle-task-oriented memory protection scheme for unmanned systems

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Science China(Information Sciences) 2024年第6期67卷 399-417页

作者： Chengyan ma Ning XI di lU Yebo FENG Jianfeng ma School of Cyber Engineering Xidian University School of Computer Science and Technology Xidian University department of Computer and Information Science University of Oregon

Memory corruption attacks(MCAs) refer to malicious behaviors of system intruders that modify the contents of a memory location to disrupt the normal operation of computing systems, causing leakage of sensitive data or perturbations to ongoing processes. Unlike general-purpose systems, unmanned systems cannot deploy complete security protection schemes, due to their limitations in size, cost and *** in unmanned systems are particularly difficult to defend against. Furthermore, MCAs have diverse and unpredictable attack interfaces in unmanned systems, severely impacting digital and physical sectors. In this paper, we first generalize, model and taxonomize MCAs found in unmanned systems currently, laying the foundation for designing a portable and general defense approach. According to different attack mechanisms,we found that MCAs are mainly categorized into two types — return2libc and return2shellcode. To tackle return2libc attacks, we model the erratic operation of unmanned systems with cycles and then propose a cycle-task-oriented memory protection(CToMP) approach to protect control flows from tampering. To defend against return2shellcode attacks, we introduce a secure process stack with a randomized memory address by leveraging the memory pool to prevent Shellcode from being executed. Moreover, we discuss the mechanism by which CTo MP resists the return-oriented programming(ROP) attack, a novel variant of return2libc attacks. Finally, we implement CTo MP on CUAV V5+ with Ardupilot and Crazyflie. The evaluation and security analysis results demonstrate that the proposed approach CTo MP is resilient to various MCAs in unmanned systems with low footprints and system overhead.

关键词： unmanned system memory corruption attack memory protection system security randomized memory address

Unconfined compressive strength and failure behaviour of completely weathered granite from a fault zone

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Journal of Mountain Science 2024年第6期21卷 2140-2158页

作者： dU Shaohua ma Jinyin ma liyao ZHAO Yaqian School of Civil Engineering and Architecture Henan University of Science and TechnologyLuoyang 471023China School of Resources and Safety Engineering Central South UniversityChangsha 410083China China Railway 18th Bureau Group Co. LtdTianjin 300222 China China General Nuclear Power Corporation Shenzhen 518031China

Understanding the strength characteristics and deformation behaviour of the tunnel surrounding rock in a fault zone is significant for tunnel stability *** this study,a series of unconfined compression tests were conducted to investigate the mechanical characteristics and failure behaviour of completely weathered granite(CWG)from a fault zone,considering with height-diameter(h/d)ratio,dry densities(ρd)and moisture contents(ω).Based on the experimental results,a regression mathematical model of unconfined compressive strength(UCS)for CWG was developed using the Multiple Nonlinear Regression method(MNlR).The research results indicated that the UCS of the specimen with a h/d ratio of 0.6 decreased with the increase ofω.When the h/d ratio increased to 1.0,the UCS increasedωwith up to 10.5%and then ***ρd is conducive to the improvement of the UCS at anyω.The deformation and rupture process as well as final failure modes of the specimen are controlled by h/d ratio,ρd andω,and the h/d ratio is the dominant factor affecting the final failure mode,followed byωandρ*** specimens with different h/d ratio exhibited completely different fracture mode,i.e.,typical splitting failure(h/d=0.6)and shear failure(h/d=1.0).By comparing the experimental results,this regression model for predicting UCS is accurate and reliable,and the h/d ratio is the dominant factor affecting the UCS of CWG,followed byρd and thenω.These findings provide important references for maintenance of the tunnel crossing other fault fractured zones,especially at low confining pressure or unconfined condition.

关键词： Fault fracture zone Completely weathered granite(CWG) Unconfined compression strength(UCS) Multiple nonlinear regression model

3d simulation of image-defined complex internal features using the numerical manifold method

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Science China(Technological Sciences) 2024年第4期67卷 1023-1039页

作者： WU Jie ma GuoWei School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China Tianjin Key laboratory for Prefabricated Building and Intelligent Construction Tianjin 300401China

The numerical simulation of internal features,such as inclusions and voids,is important to analyze their impact on the performance of composite ***,the complex geometries of internal features and the induced continuous-discontinuous(C-d)deformation fields are challenges to their numerical *** this study,a 3d approach using a simple mesh to simulate irregular internal geometries is developed for the first *** the help of a developed voxel crack model,image models that are efficient when recording complex geometries are directly imported into the *** reconstructions,which are usually labor-intensive,are excluded from this ***,using image models as the geometric input,image processing techniques are applied to detect material interfaces and develop contact ***,the C-d deformations of the complex internal features are directly calculated based on the numerical manifold *** accuracy and convergence of the developed3d approach are examined based on multiple *** 3d C-d simulation of sandstones with naturally formed complex microfeatures demonstrates the capability of the developed approach.

关键词： 3d continuous-discontinuous simulation image-based simulation complex internal features numerical manifold method voxel crack model structured mesh