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10篇 您的检索式:作者名="Mengfei Lei"
    题名 作者 年代 出处 被引量
1Architecture design for reliable and reconfigurable FPGA-based GNC computer for deep space exploration显示文摘SRAM(static random access memory)-based FPGA(field programmable gate array), owing to its large capacity, high performance, and dynamical reconfiguration, has become an attractive platform for So PC(system on programmable chip) development. However, as the configuration memory and logic memory of the SRAM-based FPGA are highly susceptible to SEUs(single-event upsets) in deep space, it is a challenge to design and implement a highly reliable FPGA-based system for spacecraft, and no practical architecture has been proposed. In this paper, a new architecture for a reliable and reconfigurable FPGAbased computer in a highly critical GNC(guidance navigation and control) system is proposed. To mitigate the effect of an SEU on the system, multi-layer reconfiguration and multi-layer TMR(triple module redundancy) techniques are proposed, with a reliable reconfigurable real-time operating system(Space OS) managing the system level fault tolerance of the computer in the architecture. The proposed architecture for the reconfigurable FPGA-based computer has been implemented with COTS(commercial off the shelf) FPGA and has firstly been applied to the GNC system of a circumlunar return and reentry flight vehicle. The in-orbit results show that the proposed architecture is capable of meeting the requirements of high reliability and high availability, and can provide the expressive varying functionality and runtime flexibility for an FPGA-based GNC computer in deep space.YANG MengFei LIU Bo GONG Jian LIU HongJin HU HongKai DONG YangYang SHI Lei ZHAO YunFu MIAO ZhiFu 2016Science China(Technological Sciences)2016,59,2:10
2Influence of ocean tidal loading on InSAR offshore areas deformation monitoring显示文摘The ocean tide can cause the redistribution of the seawater mass,resulting in earth's surface deformation,namely ocean tidal loading(OTL).OTL vertical displacement may reach several centimeters,especially in coastal areas,so its effect in the field of high precision geodesy must be considered.This study concentrates on the influences of OTL on InSAR deformation measurements.We improve the osu.chinasea.2010 regional model and then compare the improved regional model with other regional models.It turns out that the improved regional model can achieve higher precision.Then we use it to replace the offshore part of the global model to generate the present model.We find that the displacement observed by the present model is 2-3 mm larger than that of other models on some sites.Finally,the present model is used to correct the deformation observed by InSAR of Shanghai and Los Angeles.A comparison between the displacements of IGS station with the corrected data shows that the OTL correction can improve the accuracy of InSAR deformation results by about 20%.Mengfei Lei Qijie Wang Xiaoli Liu Bing Xu Hongqiang Zhang 2017Geodesy and Geodynamics2017,8,1:3
3Taking advantage of glass:capturing and retaining the helium gas on the moon显示文摘Helium-3(3He)is a noble gas that has critical applications in scientific research and promising application potential as clean fusion energy.It is thought that the lunar regolith contains large amounts of helium,but it is challenging to extract because most helium atoms are reserved in defects of crystals or as solid solutions.Here,we find large amounts of helium bubbles in the glassy surface layer of ilmenite particles that were brought back by the Chang’E-5 mission.The special disordered atomic packing structure of glasses should be the critical factor for capturing the noble helium gas.The reserves in bubbles do not require heating to high temperatures to be extracted.Mechanical methods at ambient temperatures can easily break the bubbles.Our results provide insights into the mechanism of helium gathering on the moon and offer guidance on future in situ extraction.Ao Li Xiao Chen Lijian Song Guoxin Chen Wei Xu Juntao Huo Meng Gao Ming Li Lei Zhang Bingnan Yao Min Ji Yan Zhang Shaofan Zhao Wei Yao Yanhui Liu Jun-Qiang Wang Haiyang Bai Zhigang Zou Mengfei Yang Weihua Wang 2022Materials Futures2022,1,3:2
4The partitioning behavior of trace elements in subduction zones:Advances and prospects显示文摘The partitioning behavior of trace elements is of key importance for understanding the geochemical process and material cycle mechanism in subduction zones.This paper focuses on the advances and prospects on the studies of trace element partitioning in subduction zones from the following four aspects.(1)The properties of fluids derived from subducting slabs and their ability in element transport.How slab-derived solute-rich fluids and supercritical fluids are formed and what the roles and key control factors of these fluids are in transferring of elements(especially the high field strength elements)from slab to wedge are discussed.We point out that the detailed investigations of supercritical fluids may provide a new perspective for the element migration mechanism,material cycle process,arc magma genesis and so on.(2)The behavior of transition elements during mantle wedge melting.The behavior of the first row transition elements(Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn)in the mantle partial melting process is compatible or incompatible,depending on residual mineral assemblage and physicochemical conditions.The partitioning behavior of the elements such as Sc,Ti,Co,Ni and Zn whose valence states do not change in the melting process mainly depends on the residual mineral assemblage and temperature,whereas the partitioning behavior of the multivalent elements such as V and Fe is also the function of oxygen fugacity(fO_(2))in addition to mineral assemblage and temperature.Therefore,the partitioning behavior of transition elements has important applications in tracing lithologic inhomogeneity and fO_(2)of the mantle wedges.(3)The specificity of element partitioning behavior during arc magma evolution.Garnet has Dy/Yb partitioning behavior different from amphibole,and rutile has Nb/Ta partitioning behavior different from amphibole.Dy/Yb and Nb/Ta partitioning differences for these minerals enable to distinguish the specific evolution process of arc magmas.The Dy/Yb and Nb/Ta generally decrease with the increase of SiO_(2)in arc magmas,indicating that amphibole fractionation should be the most important during arc magma differentiation.(4)The behavior of sulfur and chalcophile elements and porphyry metallogeny.In subduction zones,the behavior of chalcophile elements such as Cu and Au is controlled by sulfide and fluid.Therefore,the stability of sulfide,the time at which the fluid exsolves from the melt relative to sulfide saturation,the fluid/sulfide mass ratio and fluid/melt Cu and Au partition coefficients in intermediate-felsic magma-H_(2)O systems are especially important in understanding Cu and Au enrichment in magma-hydrothermal processes.Intermediate-felsic magmas mainly originate from the differentiation of arc magmas at lower crustal reservoirs,and thus the fluid exsolution from the lower crustal reservoirs and the fluid/melt and fluid/sulfide partition coefficients of Cu and Au should be the keys to understanding quantitatively how Cu and Au are migrated from the deep crust to the shallow site of mineralization.Xiaolin Xiong Xingcheng Liu Li Li Jintuan Wang Wei Chen Mengfei Ruan Ting Xu Zhongxing Sun Fangfang Huang Jianping Li&Lei Zhang 2020Science China Earth Sciences2020,63,12:2
5Epoxidation of propylene onNaCl-modified silver catalysts with air as the oxidant显示文摘Jiqing Lu Mengfei Luo Hao Lei 2002AppliedCatalysis A: General2002,237,12:1
6Thermoelectric enhancement of p-type Si_(80)Ge_(20) alloy via co-compositing of dual oxides:Respective regulation for power factor and thermal conductivity byβ-Ga_(2)O_(3) and SiO_(2) aerogel powders显示文摘Si-based thermoelectric(TE)materials are exhibiting remarkable perspectives in self-energized applications with their special advantages.However,the relatively high total thermal conductivity(κ)prevents their TE enhancement.Here,a strategy of co-compositing dual oxides was implemented for enhancing the TE properties of p-type Si_(80)Ge_(20) bulks.Composited Ga2O_(3) was demonstrated to enhance the power factor(PF)due to the crystallization-induced effect of produced Ga by decomposition on SiGe matrix.Associating with compositing SiO_(2) aerogel(a-SiO_(2))powder,not only introduced the fine amorphous inclusions and decreased the grain size of host matrix,but also various nano morphologies were formed,i.e.,nano inclusions,precipitations,twin boundaries(TBs),and faults.Combining with the eutectic Ge,hierarchical scattering centers impeded the phonon transport comprehensively(decreasing the phonon group velocity(a v)and relaxation time)for reducing the lattice-induced thermal conductivity(lκ).As a result,a minimumκof 2.38 W·m^(−1)·K^(−1) was achieved,which is significantly dropped by 32.6%in contrast with that of the pristine counterpart.Ultimately,a maximal dimensionless figure of merit(ZT)of 0.9 was achieved at 600℃,which is better than those of most corresponding oxide-composited Si-based bulks.Huajun LAI Ying PENG Mengfei WANG Runze SHI Junliang CHEN Chengyan LIU Yifeng WANG Lei MIAO Haiqiao WEI 2023Journal of Advanced Ceramics2023,12,2:1
73D bioprinted hyaluronic acid‑based cell‑laden scaffold for brain microenvironment simulation显示文摘Treatments for lesions in central nervous system(CNS)are always faced with challenges due to the anatomical and physiological particularity of the CNS despite the fact that several achievements have been made in early diagnosis and precision medicine to improve the survival and quality of life of patients with brain tumors in recent years.Understanding the complexity as well as role of the microenvironment of brain tumors may suggest a better revealing of the molecular mechanism of brain tumors and new therapeutic directions,which requires an accurate recapitulation of the complex microenvironment of human brain in vitro.Here,a 3D bioprinted in vitro brain matrix-mimetic microenvironment model with hyaluronic acid(HA)and normal glial cells(HEBs)is developed which simulates both mechanical and biological properties of human brain microenvironment in vivo through the investigation of the formulation of bioinks and optimization of printing process and parameters to study the effects of different concentration of gelatin(GA)within the bioink and different printing structures of the scaffold on the performance of the brain matrix-mimetic microenvironment models.The study provides experimental models for the exploration of the multiple factors in the brain microenvironment and scaffolds for GBM invasion study.Liang Ma Yuting Li Yutong Wu Mengfei Yu Abdellah Aazmi Lei Gao Qian Xue Yichen Luo Hongzhao Zhou Bin Zhang Huayong Yang 2020Bio-Design and Manufacturing2020,3,3:1
8Research on the Types of Cigarette Products Preferred by Consumers显示文摘Cigarette design and improvement according to consumer needs is an important basis for market-oriented management.The preferences of cigarette consumption such as cigarette product types,packaging styles,packaging colors and packaging materials were investigated and the real needs of cigarette consumers were figured out,in order to provide specific work guidance for the development of new cigarette products.Mengfei JIANG Hongtao FENG Xuefeng HE Tao ZHANG Lei YANG Yu ZHONG Tiyuan XIA 2022Asian Agricultural Research2022,14,4:0
9An Evaluation Method for Automotive Technical and Comprehensive Performance显示文摘An objective evaluation scheme for automotive technical and comprehensive performance could provide critical and instructive insights for academic research,engineering practice,and commercial marketing of vehicles.In this paper,the technical performance index A=S∕T_(1)⋅T_(2)(m∕(s^(2)⋅L))and comprehensive performance index F=M⋅S∕T_(1)⋅T_(2),(kN⋅L^(−1),where M is the vehicle mass)are formulated by incorporating the vehicle 0–100 km⋅h^(−1) acceleration duration T_(1),100–0 km⋅h^(−1) braking duration T_(2),and fuel economy S(mileage per liter fuel at constant speed)to assess the vehicle’s longitudinal dynamic performance.A and F offer a clear physical implication of a vehicle’s acceleration capability and traction efficiency acquired per unit of fuel consumption,respectively.These indexes are used for wide case studies of popular market sedans and SUVs of joint ventures(JVs)and domestic brands in China over the last 17 years.The findings prove that this approach could be effectively and reliably utilized for the objective evaluation and analysis of the technical and comprehensive performance of automotive models.Mengfei Liu Xinyu Ouyang Ruikai Lu Zijun Hao Raphael Blumenfeld Xin Tang Gang Lei Hongwu Ouyang 2023Automotive Innovation2023,6,2:0
10Formal modelling of list based dynamic memory allocators显示文摘Existing implementations of dynamic memory allocators(DMA) employ a large spectrum of policies and techniques. The formal specifications of these techniques are quite complicated in isolation and very complex when combined. Therefore, the formal reasoning on a specific DMA implementation is difficult for automatic tools and mostly single-use. This paper proposes a solution to this problem by providing formal models for a full class of DMA, the class using various kinds of lists to manage the memory blocks controlled by the DMA. To obtain reusable formal models and tractable formal reasoning, we organise these models in a hierarchy ranked by refinement relations. We prove the soundness of models and the refinement relations using the modeling framework Event-B and the theorem prover Rodin. We demonstrate that our hierarchy is a basis for an algorithm theory for list based DMA: it abstracts various existing implementations of DMA and leads to new DMA implementations. The applications of this formalisation include model-based code generation, testing, and static analysis.Bin FANG Mihaela SIGHIREANU Geguang PU Wen SU Jean-Raymond ABRIAL Mengfei YANG Lei QIAO 2018Science China(Information Sciences)2018,61,12:0
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