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Strengthening-toughening methods and mechanisms of Mg-Li alloy:a review

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Rare Metals 2022年第4期41卷 1176-1188页

作者： Xiang Peng Wen-cai Liu Guo-Hua wu National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Magnesium-lithium(Mg-Li) alloy,as the lightest metal structure material,has unparalleled market prospects in aerospace,weapons and equipment,electronic technology,transportation,and many other ***,it is hard to balance the superlight and high strength of Mg-Li alloy,and the inferior high-temperature strength and poor high-temperature stability limit the wide application of Mg-Li *** present,the main methods to improve the mechanical properties of Mg-Li alloy are alloying,grain refinement,and compound *** domestic and overseas research progress in the strengthening and toughening methods and mechanisms of Mg-Li alloy are reviewed,and the future development of the high strength and high toughness Mg-Li alloy is prospected.

关键词： Mg-Li alloy Solution strengthening Precipitation strengthening Grain reflnement strengthening Compound strengthening

ANALYsiS ON SMALL SCALE BRIDGING IN FIBROUS MONOLITHIC CERAMICS

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Acta Mechanica Solida sinica 1999年第3期12卷 227-238页

作者： wu, ZJ cai, QH Tsing Hua Univ Dept Mech Engn Beijing 100084 Peoples R China

Based on shear lag model of interface between fiber and matrix, a new formula that relates the crack opening displacement and bridging force in fibrous monolithic ceramics was constructed under the framework of small scale bridging. This formula was applied to predict the fracture resistance or R-curve response of a three-point bending specimen made of fibrous monolithic ceramics. A parametric investigation on the influences of fiber volume fraction, fiber radius, characteristics of constituents, BN's fracture toughness and specimen's geometry on the bridging forces and fracture resistance in si3N4/BN composite was carried out. The upper and lower limits of the R-curve of si3N4/BN in small scale bridging were derived. This research revealed the role played by the above parameters in the fracture toughness of fibrous monolithic ceramics.

关键词： fibrous monolithic ceramics fiber bridging R-curve fracture toughness

Optimization of Fuel In-situ Reduction(FISR)Denitrification Technology for Cement Kiln using CFD Method

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Journal of Thermal Science 2023年第6期32卷 2256-2272页

作者： SHI Chaoting cai Jun REN Qiangqiang wu Huixing Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Dalian National Laboratory for Clean Energy Dalian116023China

Nitrogen oxides(NO_(x))from cement industry have drawn more and more attention and the existing denitrification technologies can hardly meet the increasingly stringent emission requirements in *** our previous work,fuel in-situ reduction(FISR)method was proposed to cut cement NO_(x)*** the pilot-scale precalciner in the previous experiment as objection,optimization of FISR method was conducted using CFD *** results demonstrated that NO_(x)emission decreased by 69.86%after adopting FISR *** effects of initial concentrations of NO and O_(2)in kiln gas,feeding location of the first-stage tertiary(tertiary air-I)and cement raw meal(CRM)were further *** increasing initial NO concentration,NO_(x)emission increased linearly,while the reduction rate of NO in kiln gas maintained above 80%.When O_(2)content in kiln gas is more than 4%,oxygen would more significantly promote the formation of NO_(x)and inhibit the reduction of *** dimensionless locations of tertiary air-I and CRM were *** simulation results showed that the optimal dimensionless locations are 0.6 and 1.6 for tertiary air-I and CRM,*** outputs achieved in this study will provide a strong support for the practical application of FISR method in cement industry.

关键词： cement industry precalciner pretreated fuel NO_(x)emission denitrification

Bioinspired nanotransducers for neuromodulation

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Nano Research 2024年第2期17卷 618-632页

作者： Fan Yang Xiang wu Sa cai Guosong Hong Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA wu Tsai Neurosciences Institute Stanford UniversityStanfordCA 94305USA School of Science Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

The field of neuromodulation has experienced significant advancements in the past decade,owing to breakthroughs in disciplines such as materials science,genetics,bioengineering,photonics,and *** convergence of these fields has resulted in the development of nanotransducers,devices that harness the synergies of these diverse *** nanotransducers,essential for neuromodulation,often draw inspiration from energy conversion processes found in nature for their unique *** this review,we will delve into the latest advancements in wireless neuromodulation facilitated by optical,magnetic,and mechanical *** will examine their working principles,properties,advantages,and limitations in comparison to current methods for deep brain neuromodulation,highlighting the impact of natural systems on their design and ***,we will underscore potential future directions,emphasizing how continued progress in materials science,neuroscience,and bioengineering might expand the horizons of what is achievable with nanotransducer-enabled neuromodulation.

关键词： bioinspired synthesis neuromodulation mechanoluminescence focused ultrasound nanotransducers sono-optogenetics

Research progress of rubrene as an excellent multifunctional organic semiconductor

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Frontiers of physics 2021年第1期16卷 57-71页

作者： si Liu Hongnan wu Xiaotao Zhang Wenping Hu Tianjin Key Laboratory of Molecular Optoelectronic Science Department of ChemistrySchool of ScienceTianjin University&Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin 300072China

Rubrene,a superstar in organic semiconductors,has acliieved imprecedented achievements in the application of electronic devices,and research based on its various photoelectric properties is still in *** this review,we introduced the preparation of rubrene crystal,summarized the applications in organic optoelectronic devices with the latest research achievements based on rubrene *** outlook of future research directions and cliallenges of rubrene semiconductor for applications is also provided.

关键词： rubrene organic semiconductor optoelectronic devices

IRS-Aided SWIPT Systems with Power Splitting and Artificial Noise

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China Communications 2022年第4期19卷 108-120页

作者： Baogang Li Fuqiang si Dongsheng Han wujing wu Department of Electronic and Communication Engineering North China Electric Power UniversityBaoding 071003HebeiChina Hebei Key Laboratory of Power Internet of Things Technology North China Electric Power UniversityBaoding 071003HebeiChina

Intelligent reflecting surface(IRS) is regarded as a promising technology because it can achieve higher passive beamforming gain. In particular, the IRS assisted simultaneous wireless information and power transfer(SWIPT) system can make the information decoding receivers(IDRs) have a higher signal-to-noise ratio(SNR), and the energy harvesting receivers(EHRs) have the guarantee of minimum harvested energy threshold. Motivated by the above,in this paper, we use the power splitting(PS) at the user and introduce artificial noise(AN) into the access point(AP), so that the user in system can harvest energy and decode information simultaneously,further improve the security of user. We jointly optimize the beamforming matrix at AP, the reflection phase shift at IRS and the PS ratio, in order to maximize the user’s achievable secrecy rate, subject to the user’s minimum harvested energy threshold and AP’s transmission power. Due to the introduction of PS ratio, the coupling between variables is increased,and the complexity of the problem is significantly increased. Furthermore, the problem is non-convex, so we propose an efficient algorithm based on Taylor Formula, semi-definite relaxation(SDR) and alternating optimization(AO) to get the solution. Numerical results show that the proposed IRS-SWIPT system with PS and AN achieves significant performance improvement compared with other benchmark scheme.

关键词： intelligent reflecting surface(IRS) passive beamforming power splitting SWIPT

Brain Representation of Active and Passive Hand Movements in Healthy Aged People

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中国康复医学杂志 2013年第6期28卷 523-527页

作者： cai Weisen wu Yi wu Junfa Department of Rehabilitation Huashan HospitalFudan University wuxi Tongren International Rehabilitation Hospital The Yonghe Branch of Huashan Hospital Fudan University

Objective:To reveal the neural network of active and passive hand movements. Method:Seven healthy aged people were checked, and acquired functional magnetic resonance imaging data on a 1.5T scanner. Active movement consisted of repetitive grasping and loosening of hand; passive movement involved the same movement performed by examiner. Both types of hand movements were assessed separately. These data were analysed by Statistical Parametric Mapping Microsoft. Result:The main activated brain areas were the contralateral supplemental motor area, primary motor area, primary sensory area and the ipsilateral cerebellum when subjects gripped right hands actively and passively. The supplemental area was less active in passive hand movement than active hand movement. The activated brain areas were mainly within Brodmann area 4 during active hand movement; in the contrast, the voxels triggered by passive movement were mainly within Brodmann areas 3,1,2 areas. Conclusion:The results suggest that the neural networks of passive and active tasks spared some common areas, and the passive movement could be as effective as active movement to facilitate the recovery of limbs motor function in patients with brain damage.

关键词：医疗康复美国医疗卫生行业患者护理

Towards a New Paradigm for Brain-inspired Computer Vision

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Machine Intelligence Research 2022年第5期19卷 412-424页

作者： Xiao-Long Zou Tie-Jun Huang si wu Beijing Academy of Artificial Intelligence Beijing 100084China School of Psychology and Cognitive Sciences IDG/McGovern Institute for Brain ResearchCenter for Quantitative BiologyPKU-Tsinghua Center for Life SciencesPeking UniversityBeijing 100084China National Engineering Research Center of Visual Technology School of Computer SciencePeking UniversityBeijing 100871China Institute for Artificial Intelligence Peking UniversityBeijing 100871China

Brain-inspired computer vision aims to learn from biological systems to develop advanced image processing ***,its progress so far is not *** recognize that a main obstacle comes from that the current paradigm for brain-inspired computer vision has not captured the fundamental nature of biological vision,i.e.,the biological vision is targeted for processing spatio-temporal ***,a new paradigm for developing brain-inspired computer vision is emerging,which emphasizes on the spatio-temporal nature of visual signals and the brain-inspired models for processing this type of *** this paper,we review some recent primary works towards this new paradigm,including the development of spike cameras which acquire spiking signals directly from visual scenes,and the development of computational models learned from neural systems that are specialized to process spatio-temporal patterns,including models for object detection,tracking,and *** also discuss about the future directions to improve the paradigm.

关键词： Brain-inspired computer vision spatio-temporal patterns object detection object tracking object recognition

Numerical simulation for Accuracy of Velocity Analysis in Small-Scale High-Resolution Marine Multichannel Seismic Technology

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Journal of Ocean University of China 2017年第3期16卷 370-382页

作者： LUO Di cai Feng wu Zhiqiang The Key Laboratory of Gas Hydrate Ministry of Land and ResourcesQingdao Institute of Marine Geology Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology

When used with large energy sparkers, marine multichannel small-scale high-resolution seismic detection technology has a high resolution, high-detection precision, a wide applicable range, and is very flexible. Positive results have been achieved in submarine geological research, particularly in the investigation of marine gas hydrates. However, the amount of traveltime difference information is reduced for the velocity analysis under conditions of a shorter spread length, thus leading to poorer focusing of the velocity spectrum energy group and a lower accuracy of the velocity analysis. It is thus currently debatable whether the velocity analysis accuracy of short-arrangement multichannel seismic detection technology is able to meet the requirements of practical application in natural gas hydrate exploration. Therefore, in this study the bottom boundary of gas hydrates(Bottom simulating Reflector, BSR) is used to conduct numerical simulation to discuss the accuracy of the velocity analysis related to such technology. Results show that a higher dominant frequency and smaller sampling interval are not only able to improve the seismic resolution, but they also compensate for the defects of the short-arrangement, thereby improving the accuracy of the velocity analysis. In conclusion, the accuracy of the velocity analysis in this small-scale, high-resolution, multi-channel seismic detection technology meets the requirements of natural gas hydrate exploration.

关键词： small-scale high-resolution multichannel seismic velocity analysis accuracy gas hydrate