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Wireless Communication and Broadcasting Convergence Network Throughput

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Tsinghua science and technology 2009年第6期14卷 710-717页

作者：白铂曹志刚陈巍易芝玲 State Key Laboratory on Microwave and Digital Communications Tsinghua National Laboratory for Information Science and Technology(TNList)Department of Electronic EngineeringTsinghua University hong kong applied science and technology research institute company limited(ASTRI)

Wireless communication and broadcasting convergence networks provide a potential solution to greater traffic throughput in the future. In this paper, the throughput of a convergence network is analyzed based on the standardization project for specific requirements for local and metropolitan area networks in China, referred to as broadband wireless multimedia systems. The convergence network is modeled as a combination of a broadcasting channel and a multi-access channel with interference. The throughput is then given as a function of the time resource allocation by calculating the channel capacity with interference. The maximum throughput and the optimal time resource allocation are then determined for a given delay constraint and traffic requirements. The results give guidelines for time resource allocation and system design for convergence networks.

关键词： wireless convergence network broadcasting channel multi-access channel interference

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Ultra-sensitive hybrid diamond nanothermometer

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National science Review 2021年第5期8卷 76-84页

作者： Chu-Feng Liu Weng-Hang Leong Kangwei Xia Xi Feng Amit Finkler Andrej Denisenko J?rg Wrachtrup Quan Li Ren-Bao Liu Department of Physics The Chinese University of Hong Kong 3rd institute of Physics and Center for applied Quantum Technologies University of Stuttgart Department of Chemical and Biological Physics Weizmann Institute of Science Max Planck institute for Solid State research The hong kong institute of Quantum Information science and technology The Chinese University of Hong Kong

Nitrogen-vacancy（NV） centers in diamond are promising quantum sensors because of their long spin coherence time under ambient conditions. However, their spin resonances are relatively insensitive to non-magnetic parameters such as temperature. A magnetic-nanoparticle-nanodiamond hybrid thermometer, where the temperature change is converted to the magnetic field variation near the Curie temperature, were demonstrated to have enhanced temperature sensitivity(11 m K Hz-1/2)（Wang N, Liu G-Q and Leong W-H et al. Phys Rev X 2018; 8: 011042）, but the sensitivity was limited by the large spectral broadening of ensemble spins in nanodiamonds. To overcome this limitation, here we show an improved design of a hybrid nanothermometer using a single NV center in a diamond nanopillar coupled with a single magnetic nanoparticle of copper-nickel alloy, and demonstrate a temperature sensitivity of 76 μK Hz-1/*** hybrid design enables detection of 2 m K temperature changes with temporal resolution of 5 ms. The ultra-sensitive nanothermometer offers a new tool to investigate thermal processes in nanoscale systems.

关键词： nano-thermometry diamond nitrogen-vacancy center quantum sensing magnetic nanoparticle

Optical fibre based artificial compound eyes for direct static imaging and ultrafast motion detection

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Light(science & Applications) 2024年第11期13卷 2649-2667页

作者： Heng Jiang Chi Chung Tsoi Weixing Yu Mengchao Ma Mingjie Li Zuankai Wang Xuming Zhang Department of applied Physics The Hong Kong Polytechnic University999077 Hong KongChina Photonics research institute(PRI) The Hong Kong Polytechnic University999077 Hong KongChina Key Laboratory of Spectral Imaging technology Xi’an Institute of Optics and Precision MechanicsChinese Academy of Sciences710119 Xi’anChina Anhui Province Key Laboratory of Measuring Theory and Precision Instrument School of Instrument Science and Opto-Electronics EngineeringHefei University of Technology230009 HefeiChina Department of Mechanical Engineering The Hong Kong Polytechnic University999077 Hong KongChina research institute for Advanced Manufacturing(RIAM) The Hong Kong Polytechnic University999077 Hong KongChina

Natural selection has driven arthropods to evolve fantastic natural compound eyes(NCEs)with a unique anatomical structure,providing a promising blueprint for artificial compound eyes(ACEs)to achieve static and dynamic perceptions in complex ***,each NCE utilises an array of ommatidia,the imaging units,distributed on a curved surface to enable abundant *** has inspired the development of many ACEs using various microlens arrays,but the reported ACEs have limited performances in static imaging and motion ***,it is challenging to mimic the apposition modality to effectively transmit light rays collected by many microlenses on a curved surface to a flat imaging sensor chip while preserving their spatial relationships without *** this study,we integrate 271 lensed polymer optical fibres into a dome-like structure to faithfully mimic the structure of *** ACE has several parameters comparable to the NCEs:271 ommatidia versus 272 for bark beetles,and 180° field of view(FOV)versus 150–180° FOV for most *** addition,our ACE outperforms the typical NCEs by~100 times in dynamic response:31.3 kHz versus 205 Hz for Glossina *** with other reported ACEs,our ACE enables real-time,180° panoramic direct imaging and depth estimation within its nearly infinite depth of ***,our ACE can respond to an angular motion up to 5.6×10^(6)deg/s with the ability to identify translation and rotation,making it suitable for applications to capture high-speed objects,such as surveillance,unmanned aerial/ground vehicles,and virtual reality.

关键词： field. compound enable

Drivability of Large Diameter Steel Cylinders During Hammer-Group Vibratory Installation for the hong kong–Zhuhai–Macao Bridge

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Engineering 2023年第1期20卷 180-191页

作者： W.J.Lu B.Li J.F.Hou X.W.Xu H.F.Zou L.M.Zhang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyKowloonHong Kong 999077China The hong kong University of science and technology Shenzhen research institute Shenzhen 518057China Tianjin Port Engineering institute Co. Ltd.of CCCC First Harbor Engineering Co.Ltd.Tianjin 300222China Key Laboratory of Port Geotechnical Engineering Ministry of Communications of People’s Republic of ChinaTianjin 300222China CCCC First Harbor Engineering company Ltd. Tianjin 300461China AECOM Asia company limited Hong Kong 999077China

The hong kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer *** to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers,predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the *** this study,the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys,field monitoring,and drivability *** vibratory penetration rate,installation accuracy,and dynamic responses of the steel cylinders at both the eastern and western artificial islands are *** dynamic soil resistance has a great influence on the cylinder ***,the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale ***,a modified method with a normalized effective area ratio A_(r,eff)is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged *** the scale effects on the vibratory driving soil resistance,the proposed method leads to closer results to the measured data,providing a reference for future engineering practice.

关键词： hong kong-Zhuhai-Macao Bridge Vibratory pile driving Wave equation analysis Large-diameter steel cylinder Artificial island offshore foundati ons

Bandwidth Allocation in WiMedia UWB Networks

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Bandwidth Allocation in WiMedia UWB Networks

An overview on AIEgen-decorated porphyrins:Current status and applications

2005年全国超宽带无线通信技术学术会议

作者： Kit Wah LAU hong kong applied science technology research institute company limited

＜正＞UWB has boosted research and development interest recently in wireless personal area networks （WPANs）. To facilitate the efficient sharing of wireless radio medium, WiMedia Alliance has defined a set of radio sharing rules. Among these, medium access slot （MAS） sharing principles play an important role in bandwidth allocation. This paper discusses MAS allocation rules and presents an algorithm to implement these rules. Simulation results show that these rules can be satisfied by the proposed algorithm.

关键词： UWB WPAN bandwidth allocation MAS.

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Aggregate 2023年第3期4卷 55-70页

作者： Govardhana Babu Bodedla Xunjin Zhu Wai-Yeung Wong Department of applied Biology&Chemical technology and research institute for Smart Energy The Hong Kong Polytechnic UniversityHong KongP.R.China The hong kong Polytechnic University Shenzhen research institute ShenzhenP.R.China Department of Chemistry Hong Kong Baptist UniversityHong KongP.R.China

One of the major obstacles of porphyrins is the aggregation-caused quenching(ACQ)of photoluminescence due to the strong intermolecularπ–πinteraction of the planar porphyrin core in the solid ***,ACQ leads to the nonradiative deactivation of the photoexcited states which results in short-lived charge-separated states and thus low photoluminescence and singlet quantum *** phenomenon would limit the utilization of porphyrins in near-infrared fluorescent bioimaging,photodynamic therapy,photocatalytic hydrogen evolution,electrochemiluminescence,and chiroptical ***,to address the ACQ property of porphyrins and enhance the performance of the above applications,a limited number of AIEgen-decorated porphyrins have been designed,synthesized,and tested for their *** has been found that the introduction of AIEgens,such as tetraphenylethylene,diphenylacrylonitrile,(3,6-bis-(1-methyl-4-vinylpyridinium)-carbazole diiodide,and iridium motif into the porphyrin core,transformed the porphyrins from ACQ to aggregation-induced emission(AIE)in their solid state due to the reduced strong intermolecularπ–πstacking of ***,such porphyrins containing AIE features are employed as potential candidates in the above-mentioned *** this review,we summarize the AIEgen-decorated porphyrins which have been published to date,and also discuss the benefits of converting porphyrins from ACQ to AIE for enhanced performance within each *** far as we know,there is no review that summarizes the structures and applications of AIEgen-decorated porphyrins to ***,we presume that this review would be helpful to design more efficient AIEgen-decorated porphyrins for a wide range of applications in the future.

关键词： aggregation-caused quenching aggregation-induced emission AIE luminogen FRET and solid state emission porphyrin

Transmission Power Control in WiMedia UWB Networks

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Transmission Power Control in WiMedia UWB Networks

Amorphous silicon from low-temperature reduction of silica in the molten salts and its lithium-storage performance

2005年全国超宽带无线通信技术学术会议

作者： Raymond Yan Lam LEE hong kong applied science technology research institute company limited（ASTRI）

＜正＞Ad-hoc network utilizing Ultra-wide band （UWB） technologies has become a major focus for wireless personal area network （WPAN）. However, most of the portable devices are driven by batteries. In order to extend the battery life of a portable device, effective transmission power control （TPC） is very important. This paper discusses the requirements and implementation of the TPC algorithm for UWB networks. Simulation results show that TPC can save around 70% to 90% of power for devices separated by short distances and around 10% to 50% for devices separated by long distances.

关键词： UWB WPAN TPC.

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Chinese Chemical Letters 2021年第2期32卷 598-603页

作者： Xi Huang Xuyun Guo Yicheng Ding Run Wei Shengnan Mao Ye Zhu Zhihao Bao Shanghai Key Laboratory of Special Artificial Microstructure Materials and technology School of Physics Science and EngineeringTongji University.Shanghai 200092China Department of applied Physics Research Institute for Smart EnergyHong Kong Polytechnic UniversityHong KongChina

Amorphous silicon(a-Si) is one of the most promising anode-materials for the lithium-ion battery owing to its large capacity and superior fracture ***,a-Si is usually fabricated with the sophisticated chemical vapor deposition or pulse laser deposition in a limited *** this work,we have succes s fully pre pared a-Si spheres(~200 nm) by reducing the TiO2-coated silica spheres with Al powders in the molten salts at 300℃.The coated TiO2 layer acts as a protective layer for structural maintenance during the reduction and a precursor for *** doped Ti element may suppress the crystal growth of Si to facilitate the formation of *** observation with in-situ transmission electron microscopy(TEM) further reveals that lithiation kinetics of the synthesized a-Si is controlled by the interfacial *** Li^(+) diffusivity in a-Si determined from the observation is in the order of 10^(-14) cm^(2)/*** anode of a-Si spheres together with crystalline Si nanoparticles exhibits excellent electrochemical performance,delivering a reversible capacity of 1604 mAh/g at 4 A/g and a capacity retention of 78,3%after 500 *** low temperature reduction process reported in this study provides a low-cost method to fabricate a-Si nanostructures as high-capacity durable anode materials.

关键词： Amorphous Molten salt Lithium-ion battery Silicon anode Doping

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Integrating multiple images in a sampled phase-only hologram

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Chinese Optics Letters 2019年第5期17卷 11-14页

作者： P. W. M. Tsang T.-C. Poon W. Wang X. Zhu K. Chan Department of Electronic Engineering City University of Hong KongHong Kong SARChina Bradley Department of Electrical and Computer Engineering Virginia TechBlacksburgVirginia 24061USA hong kong applied science and technology research institute company limited Hong Kong SARChina

Past research has demonstrated that a sampled phase-only hologram (SPOH) is capable of representing an image without the magnitude component of the hologram. At present, an SPOH can only record and reconstruct a single source image. In this Letter, we propose, for the first time, to the best of our knowledge, a method for representing multiple images with a single integrated SPOH (ISPOH). Subsequently, each image can be retrieved from the ISPOH with a unique key parameter and displayed as a visible image on a phase-only spatial light modulator.

关键词： Integrating multiple images sampled phase-only hologram magnitude component

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