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Architecture of Graphics System with 3D Acceleration Support for Embedded Operating Systems

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Tsinghua Science and Technology 2024年第3期29卷 863-873页

作者： Alexander Giatsintov Kirill Mamrosenko Pavel Bazhenov Center of Visualization and Sattelite Information Technologies Scientific Research Institute for System Analysis of the Russian Academy of Sciences(SRISA RAS)Moscow 117218Russia

An increasing number of tasks now require the use of hardware accelerators to reduce the time required for computation and display the computational *** paper presents a new graphics system architecture for operating systems(OSs)with microkernel architecture,including real-time *** proposed system architecture provides capabilities for displaying graphical images on various information display devices and for accelerating graphical operations on *** architecture of the graphics system uses a concept of allocators to manage system and video memory,provides an abstraction of memory operations with a single interface for video memory management,and simplifies memory handling where incorrect operation is the cause of many failures.A comparison between the performance of a real-time OS and Linux OS implementing the graphics system using the example of a glmark2 benchmark is presented,thereby the superiority of the proposed architecture in several scenarios is demonstrated.

关键词： real-time operating system(RTOS) graphics system rendering system architecture operatingsystem visualization system programming

Effect of Ball Milling Time on Microstructure and Hydrogen Storage Properties of Nd_(5)Mg_(41)Ni Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1201-1214页

作者： Zeming Yuan Chenxu Liu Xiaoming Li Yongqi Sui Zhonggang Han Tingting Zhai Dianchen Feng Yanghuan Zhang Instrumental analysis Center Inner Mongolia University of Science and TechnologyBaotou014010China Department of Functional Material research Central Iron and Steel Research InstituteBeijing100081China

Mg-based alloys must be dehydrogenated at high pressure and temperatures, limiting their practical application. In this paper, Nd_(5)Mg_(41)Ni alloy was prepared by vacuum melting, and the as-cast alloy was ball milled for 5 h, 10 h, 15 h, and 20 h. The effect of ball milling time on the microstructure and hydrogen storage properties of the alloy was systematically studied. The alloy comprises Nd_(5)Mg_(41), NdMg_(12), NdMg_(3), and Mg_(2)Ni phases. The Nd_(5)Mg_(41)Ni alloy milling for 10 h can reach 95% of the saturated hydrogen absorption at 553 K by 40 s, and the alloy can desorb hydrogen only by 20 min. The dehydrogenation activation energy is only 99.9 kJ/mol H_(2). Ball milling makes the alloy produce many nanocrystalline and amorphous structures. The nano-grain boundary provides a channel for the diffusion of hydrogen atoms, and the high energy at the grain boundary provides energy for the phase deformation nucleus. Ball milling leads to the refinement of alloy particles and shortens the diffusion distance of hydrogen atoms to the interior of alloy particles. Defects such as twins and dislocations generated by milling provide energy for the phase deformation nucleus during the hydrogen absorption and desorption.

关键词： Hydrogen storage materials Magnesium-base alloy Ball milling Nanocrystal Kinetics

Hot carrier cooling in lead halide perovskites probed by two-pulse photovoltage correlation spectroscopy

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Chinese Physics B 2024年第10期33卷 116-119页

作者： Yuqing Huang Chaoyu Guo Lei Gao Wenna Du Haotian Zheng Da Wu Zhengpu Zhao Chu-Wei Zhang Qin Wang Xin-Feng Liu Qingfeng Yan Ying Jiang International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Quantum matter Beijing 100871China Department of Chemistry Tsinghua UniversityBeijing 100084China CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Interdisciplinary institute of Light-element Quantum Materials and research Center for Light-element Advanced Materials Peking UniversityBeijing 100871China

The next-generation hot-carrier solar cells,which can overcome the Shockley-Queisser limit by harvesting excessenergy from hot carriers,are receiving increasing *** halide perovskite(LHP)materials are considered aspromising candidates due to their exceptional photovoltaic properties,good stability and low *** cooling rate of hotcarriers is a key parameter influencing the performance of hot-carrier solar *** this work,we successfully detected hotcarrier dynamics in operando LHP devices using the two-pulse photovoltage correlation *** enhance the signalto-noise ratio,we applied the delay-time modulation method instead of the traditional power *** advancementallowed us to detect the intraband hot carrier cooling time for the organic LHP CH_(3)NH_(3)PbBr_(3),which is as short as 0.21 *** comparison,the inorganic Cs-based LHP CsPbBr_(3)exhibited a longer cooling time of around 0.59 ps due to differentphonon *** results provide us new insights into the optimal design of hot-carrier solar cells and highlightthe potential of LHP materials in advancing solar cell technology.

关键词： two-pulse correlation spectroscopy lead halide perovskites hot carrier cooling ultrafast dynamics

Interaction between Surface Acoustic Wave and Quantum Hall Effects

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Chinese Physics Letters 2024年第4期41卷 105-109页

作者：刘萧吴蒙蒙王任飞王兴豪张文锋董昱江杜瑞瑞刘阳林熙 International Center for Quantum Materials Peking UniversityBeijing 100871China Center for Excellence University of Chinese Academy of SciencesBeijing 100190China Hefei National Laboratory Hefei 230088China Interdisciplinary institute of Light-element Quantum Materials and research Center for Light-element Advanced Materials Peking UniversityBeijing 100871China

Surface acoustic wave(SAW)is a powerful technique for investigating quantum phases appearing in twodimensional electron *** electrons respond to the piezoelectric field of SAW through screening,attenuating its amplitude,and shifting its velocity,which is described by the relaxation *** this work,we systematically study this interaction using orders of magnitude lower SAW amplitude than those in previous *** high magnetic fields,when electrons form highly correlated states such as the quantum Hall effect,we observe an anomalously large attenuation of SAW,while the acoustic speed remains considerably high,inconsistent with the conventional relaxation *** anomaly exists only when the SAW power is sufficiently low.

关键词： relaxation quantum inconsistent

Layered kagome compound Na_(2)Ni_(3)S_(4)with topological flat band

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Chinese Physics B 2024年第5期33卷 153-159页

作者：叶君耀林益浩王浩哲宋志达冯济谢韦伟贾爽 International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Department of Chemistry Michigan State UniversityMI48824USA Hefei National Laboratory Hefei 230088China Interdisciplinary institute of Light-element Quantum Materials and research Center for Light-element Advanced Materials Peking UniversityBeijing 100871China

We report structural and electronic properties of Na_(2)Ni_(3)S_(4),a quasi-two-dimensional compound composed of alternating layers of[Ni_(3)S_(4)]^(2-)and Na^(+).The compound features a remarkable Ni-based kagome lattice with a square planar configuration of four surrounding S atoms for each Ni *** and electrical measurements reveal a weak paramagnetic insulator with a gap of about 0.5 *** band structure calculation highlights a set of topological flat bands of the kagome lattice derived from the rotated dxz-orbital with C_(3)+T symmetry in the presence of crystal-field splitting.

关键词： kagome lattice flat band

Apatite Fission-Track Thermochronology in the Tamusu Area,Bayingobi Basin,NW China,and its Geological Significance

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 585-601页

作者： TONG Qinlong QIN Mingkuan YE Fawang CNNC Beijing research institute of Uranium Geology National Key Laboratory of Remote Sensing Information and Image Analysis TechnologyBeijing 100029China

The Bayingobi basin is located in the middle of Central Asia Orogenic Belt,at the intersection of Paleo-Asian Ocean and Tethys Ocean,as well as the junction of multiple tectonic *** unique tectonic setting underpins the basin's intricate history of tectonic *** unravel the multifaceted tectono-thermal evolution within the southwestern region of the basin and to elucidate the implications of sandstone-hosted uranium mineralization,granitic and clastic rock samples were collected from the Zongnai *** and Yingejing depression,and apatite fission track(AFT)dating and thermal history simulation analysis were *** dating findings reveal that the apparent ages of all samples fall within the range of 244 Ma to 112 *** particular,the bedrock of the Zongnai *** Jurassic detrital apatite fission tracks have undergone complete annealing,capturing the uplift-cooling ***,the AFT ages of Cretaceous detrital rocks are either equivalent to or notably exceed the age of sedimentary strata,signifying the cooling age of the provenance.A comprehensive examination of AFT ages and palaeocurrent direction analyses suggests that the Cretaceous source in the Tamusu area predominantly originated from the central and southern sectors of the Zongnai ***,at a certain juncture during the Late Early Cretaceous,the Cretaceous provenance expanded to include the northern part of the Zongnai *** on the results of thermal history simulations and previous studies,it is considered that the Tamusu area has undergone four distinct tectonic uplift events since the Late *** first is the Late Permian to Early Triassic(260-240 Ma),which is associated with the closure of the Paleo-Asian Ocean and the accretionary orogeny within the Alxa *** second uplift event took place in the Early Jurassic(190-175 Ma)and corresponded to intraplate orogeny following the closure of the Paleo-Asian *** third uplift event is the Lat

关键词： apatite fission-track tectono-thermal history sandstone-hosted uranium deposit Bayingobi basin Central Asian Orogenic Belt

Spin-polarized pairing induced by the magnetic field in the Bernal bilayer graphene

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Chinese Physics B 2024年第4期33卷 650-654页

作者：黄妍周涛 Guangdong Basic research Center of Excellence for Structure and Fundamental Interactions of matter Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum MaterialsSchool of PhysicsGuangdong-Hong Kong Joint Laboratory of Quantum Matterand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China

Recent experimental findings have demonstrated the occurrence of superconductivity in Bernal bilayer graphene when induced by a magnetic *** this study,we conduct a theoretical investigation of the potential pairing symmetry within this superconducting *** developing a theoretical model,we primarily calculate the free energy of the system with p+ip-wave parallel spin pairing,p+ip-wave anti-parallel spin pairing and d+i d-wave pairing *** results confirm that the magnetic field is indeed essential for generating the *** discover that the p+ip-wave parallel spin pairing leads to a lower free energy for the *** numerical calculations of the energy band structure,zero-energy spectral function and density of states for each of the three pairing symmetries under consideration show a strong consistency with the free energy results.

关键词： superconductivity magnetic field induction pairing symmetry Bernal bilayer graphene

Real-time estimation of the structural utilization level of segmental tunnel lining

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Underground Space 2024年第4期17卷 132-145页

作者： Nicola Gottardi Steffen Freitag Gunther Meschke institute for Structural Mechanics Ruhr University BochumBochum 44801Germany institute for Structural analysis Karlsruhe Institute of TechnologyKarlsruhe 76131Germany

Over the last decades,an expansion of the underground network has been taking place to cope with the increasing amount of moving people and *** a consequence,it is of vital importance to guarantee the full functionality of the tunnel network by means of preventive maintenance and the monitoring of the tunnel lining state over time.A new method has been developed for the real-time prediction of the utilization level in tunnel segmental linings based on input monitoring *** new concept is founded on a framework,which encompasses an offline and an online *** the former,the generation of feedforward neural networks is accomplished by employing synthetically produced *** element simulations of the lining structure are conducted to analyze the structural response under multiple loading *** scenarios are generated by assuming ranges of variation of the model input parameters to account for the uncertainty due to the not fully determined in situ *** and target quantities are identified to better assess the structural utilization of the *** latter phase consists in the application of the methodological framework on input monitored data,which allows for a real-time prediction of the physical quantities deployed for the estimation of the lining *** approach is validated on a full-scale test of segmental lining,where the predicted quantities are compared with the actual ***,it is investigated the influence of artificial noise added to the training data on the overall prediction performances and the benefits along with the limits of the concept are set out.

关键词： Segmental lining Artificial neural networks Structural utilization level Real-time prediction Structural health monitoring Monitoring data

A simulation-based software to support the real-time operational parameters selection of tunnel boring machines

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Underground Space 2024年第1期14卷 176-196页

作者： Yaman Zendaki Ba Trung Cao Abdullah Alsahly Steffen Freitag Gunther Meschke institute for Structural Mechanics Ruhr University BochumBochum 44801Germany institute for Structural analysis Karlsruhe Institute of TechnologyKarlsruhe 76131Germany

With the fact that the main operational parameters of the construction process in mechanized tunneling are currently selected based on monitoring data and engineering experience without exploiting the advantages of computer methods,the focus of this work is to develop a simulation-based real-time assistant system to support the selection of operational *** choice of an appropriate set of these parameters(i.e.,the face support pressure,the grouting pressure,and the advance speed)during the operation of tunnel boring machines(TBM)is determined by evaluating different tunneling-induced soil-structure interactions such as the surface settlement,the associated risks on existing structures and the tunnel lining *** evaluate soil-structure behavior,an advanced process-oriented numerical simulation model based on the finite cell method is *** enable the real-time prediction capability of the simulation model for a practical application during the advancement of TBMs,surrogate models based on the Proper Orthogonal Decomposition and Radial Basis Functions(POD-RBF)are *** proposed approach is demonstrated through several synthetic numerical examples inspired by the data of real tunnel *** developed methods are integrated into a user-friendly application called SMART to serve as a support platform for tunnel engineers at construction *** to each user adjustment of the input parameters,i.e.,each TBM driving scenario,approximately two million outputs of soil-structure interactions are quickly predicted and visualized in seconds,which can provide the site engineers with a rough estimation of the impacts of the chosen scenario on structural responses of the tunnel and above ground structures.

关键词： Numerical simulation Surrogate model Real-time prediction Proper orthogonal decomposition Radial basis functions TBM operation Smart construction