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Phase Diffusion in Single-Walled Carbon Nanotube Josephson Transistors

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Nano Research 2008年第2期1卷 145-151页

作者： Yong Zhang Gang Liu ch.n Ning lau Department of Physics&Astronomy University of CaliforniaRiversideCA 92521USA Present address:Sch.ol of Physical Science&Tech.ology Southwest UniversityChongqing 400715China

We investigate electronic transport in Josephson junctions formed by individual single-walled carbon nanotubes coupled to superconducting *** observe enhanced zero-bias conductance(up to 10e2/h)and pronounced sub-harmonic gap structures in differential conductance,which.arise from the multiple Andreev refl ections at superconductor/nanotube *** voltage-current ch.racteristics of these junctions display abrupt switch.ng from the supercurrent branch.to the resistive branch.with a gate-tunable switch.ng current ranging from 65 pA to 2.5 *** fi nite resistance observed on the supercurrent branch.and the magnitude of the switch.ng current are in good agreement with the classical phase diffusion model for resistively and capacitively shunted junctions.

关键词： Carbon nanotubes Josephson junctions quantum dot electrical transport supercurrent

Structural, mech.nical and corrosion properties of CNT-304 stainless steel nanocomposites

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Progress in Natural Science:Materials International 2019年第5期29卷 595-602页

作者： A.V.Radhamani Hon ch.ng lau S.Ramakrishna Department of Civil and Environmental Engineering National University of Singapore Department of Mech.nical Engineering Centre for Nanofibers and Nanotechnology National University of Singapore

In this work, a systematic investigation was performed on the structural, mech.nical and corrosion properties of CNT incorporated 304 stainless steel. Various concentrations of CNT from 0.5 to 4 wt% were incorporated into the 304 stainless steel matrix to investigate the feasibility of fabrication and enhancement of strength and other material properties. The fabrication of CNT-steel composite was ach.eved through a spark plasma sintering process at a sintering temperature of 800℃. Raman and morphological studies confirmed that the CNT structure was retained in the sintered pellets. Optimum performance was found at 0.5 wt% CNT giving a Vickers hardness of 351 Hv and compressive yield strength of 404 MPa which.were 5.5 and 2.0 times, respectively, those of pristine steel. Corrosion studies with 3.5 wt% Na Cl solution revealed a slight increase in the corrosion rate for CNT dispersed samples.

关键词： Carbon nanotube 304-Stainless steel Spark plasma sintering Hardness Compression Corrosion

CD40-activated B cells are more potent than immature dendritic cells to induce and expand CD41 regulatory T cells

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Cellular & Molecular Immunology 2010年第1期7卷 44-50页

作者： Jian Zheng Yinping Liu Yu-Lung lau Wenwei Tu Department of Paediatrics and Adolescent Medicine Li Ka Shing Faculty of MedicineUniversity of Hong KongHong KongChina Joint Research.Centre West China Second University HospitalSichuan University and Faculty of MedicineUniversity of Hong KongChengduChina

CD4^(+)regulatory T cells(Tregs)play an important role in maintaining immune tolerance by suppressing pathologic immune responses.,The generation of large numbers of antigen-specific Tregs ex vivo is critical for the development of clinical immunotherapy based on the adoptive transfer of *** CD40-activated B cells(CD40-B)and immature dendritic cells(imDCs)have been used as professional antigen-presenting cells(APCs)to generate antigen-specific ***,the efficiencies of CD40-B and imDCs to generate CD4^(+)Tregs have not been compared directly and the mech.nism driving the generation of these Tregs remains largely *** this study,we found that CD40-B exhibited mature phenotypes and were more able to induce and expand CD4^(high)"CD25^(+)Tregs than ***,Tregs induced by CD40-B had greater suppressive capacity than those induced by *** generation of CD4^(high)CD25^(+)Tregs by CD40-B and imDCs is cell-cell contact dependent and partially relies on the expression of human leukocyte antigen(HLA)-DR and CD80/*** in CD4^(high)CD25^(+)Treg generation efficiency were largely explained by the production of endogenous IL-2 by *** results suggest that CD40-B is better able to generate large numbers of antigen-specific Tregs than ***,using CD40-B to generate Tregs may accelerate the clinical use of Treg-based immunotherapy in the treatment of allograft rejection,graft versus host disease(GVHD)and autoimmune diseases.

关键词： B cells immature DC Treg IL-2

Post-disaster Psych.social Capacity Building for Women in a ch.nese Rural Village

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International Journal of Disaster Risk Science 2019年第2期10卷 193-203页

作者： Timothy Sim Jocelyn lau Ke Cui Hsi-Hsien Wei Department of Applied Social Sciences The Hong KongPolytechnic UniversityHong KongChina World Health Organization Collaborating Centre forCommunity Health Services School of NursingThe HongKong Polytechnic UniversityHong KongChina Sch.ol of Public Administration Sichuan UniversityChengdu610065China Department of Building and Real Estate The Hong KongPolytechnic UniversityHong KongChina

Mental health interventions following disasters have been criticized as individualistic, incomplete, and culturally insensitive. This article showcases the effects of a culturally relevant and sustainable psych.social capacitybuilding project at the epicenter of the 2008 Wench.an Earthquake. Specifically, the project focuses on women, a group that has received limited attention in post-disaster recovery in ch.na. This qualitative research.study(N = 14)sheds light on the ch.racteristics and processes of the implementation of a post-disaster psych.social intervention project in rural ch.na. In addition, by adopting the Success Case Method as an evaluation approach. this study elucidates its effects on the psych.logical and social ch.nges of the disaster victims. The findings capture five aspects of psych.social ch.nges: enrich.d daily life, better mood,enhanced self-confidence, increased willingness to socialize, and the provision of mutual help. This study hopes to encourage more culturally relevant and empowering practices for women in building their psych.social capacity after disasters.

关键词： ch.na Natural hazard-induced disasters Post-disaster recovery Psych.social capacity building Success case method Women’ empowerment

On ch.nnel quantization for multi-cell cooperative systems with limited feedback

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Science ch.na(Information Sciences) 2013年第2期56卷 74-89页

作者： HOU XueYing YANG ch.nYang lau Buon Kiong Sch.ol of Electronics and Information Engineering Beihang University Department of Electrical and Information Tech.ology Lund University

Coherent multi-cell cooperative transmission, also referred to as coordinated multi-point transmission (CoMP), is a promising strategy to provide high spectral efficiency for universal frequency reuse cellular systems. To report the required ch.nnel information to the transmitter in frequency division duplexing systems, limited feedback tech.iques are often applied. Considering that the average ch.nnel gains from multiple base stations (BSs) to one mobile station are different and the number of cooperative BSs may be dynamic, it is neither flexible nor compatible to employ a large codebook to directly quantize the CoMP ch.nnel. In this paper, we employ per-cell codebooks for quantizing local and cross ch.nnels. We first propose a codeword selection criterion, aiming at maximizing an estimated data rate for each.user. The proposed criterion can be applied for an arbitrary number of receive antennas at each.user and also for an arbitrary number of data streams transmitted to each.user. Considering that the resulting optimal per-cell codeword selection for CoMP ch.nnel is of high complexity, we propose a serial codeword selection method that has low complexity but yields comparable performance to that of the optimal codeword selection. We evaluate the proposed codeword selection criterion and method using measured CoMP ch.nnels from an urban environment as well as simulations. The results demonstrate significant performance gain as compared to an existing low-complexity method.

关键词： base station cooperative transmission ch.nnel quantization limited feedback codeword selection

Preserving the literary past, looking to the future: the first Hong Kong Literature Database

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第11期6卷 1341-1347页

作者： MA Leo F.H. WONG Rita lau Paul University Library System The Chinese University of Hong Kong Hong Kong ChinaUniversity Library System The Chinese University of Hong Kong Hong Kong ChinaUniversity Library System The Chinese University of Hong Kong Hong Kong China

In the last two decades of the 20th century, there has been an increasing interest in and emphasis on the study of the Hong Kong literature in both the academic and general public in Hong Kong. Recognizing the emergent need of the resources on Hong Kong literature, the University Library System of the ch.nese University of Hong Kong set up the Hong Kong Literature Database （the “Database”）, which.was the first ch.nese literature database in the Internet in 2000. The paper will examine how the database is constructed using XML tech.ology andometadata sch.ma, The database also employs Unicode UTF-8 as the internal code. A mapping table for traditional and simplified ch.nese ch.racters was created based on Unihan and is used behind the scene so that a user can either input traditional or simplified ch.nese ch.racters and retrieval will give both traditional and simplified ch.nese ch.racters. Currently 65% of journals use OCR tech.ology so that full-text search.ng is possible. The ch.nese OCR tech.ology will be examined in greater detail. Special features of the Database such.as, page-by-page browse mode, position-highlight for full-page newspaper, linking Table-Of-Contents and book jackets from the Library catalogue, etc. are described. The paper will also bring out the problem of massive downloading and compare the state-of-the-art tech.ology and their shortcomings. This paper shows how the Hong Kong Literature Database facilitates future collaboration and data exch.nge by using open standard, shareable structure and the latest tech.ology.

关键词： Hong Kong Literature Hong Kong Literature Database XML Metadata sch.ma Database structure UnicodeUTF-8 OCR tech.ology

Regulation of cytohesins by their interactors in the nervous system

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Neural Regeneration Research 2023年第10期18卷 2186-2187页

作者： Yuqi Zhai King To Leung Kwok-Fai lau Sch.ol of Life Sciences Faculty of ScienceThe Chinese University of Hong KongHong Kong Special Administrative RegionChina

Adenosine diphosphate ribosylation factors(ARFs) are small GTP-binding proteins of the Ras superfamily which.are involved in membrane trafficking and actin cytoskeleton *** other small GTPases,their functions are attributed to the cycling of ARF between GTP(active) and GDP (inactive) states through the actions of guanine nucleotide exch.nge factors (GEFs) and GTPase-activating proteins,respectively.

关键词： Adenosine cycling attributed

Recent Advances in Directed Assembly of Nanowires or Nanotubes

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Nano-Micro Letters 2012年第3期4卷 142-153页

作者： Mei Liu Zhizheng Wu Woon Ming lau Jun Yang Sch.ol of Mech.tronics Engineering and Automation Shanghai University State Key Laboratory of Transducer Tech.ology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences Green Energy and Green Manufacturing Tech.ology R&D Center Department of Mech.nical and Materials Engineering the University of West ern Ontario

Nanowires and nanotubes of diverse material compositions,properties and/or functions have been produced or fabricated through various bottom-up or top-down *** nanowires or nanotubes have also been utilized as potential building blocks for functional *** key for the integration of those nanowire or nanotube based devices is to assemble these one dimensional nanomaterials to specific locations using tech.iques that are highly controllable and *** such.tech.iques should enable assembly of highly uniform nanowire/nanotube arrays with precise control of density,location,dimension or even material types of nanowires/*** assembly tech.iques are being developed that can quickly align and assemble large quantities of one type or multiple types of nanowires through parallel processes,including flow-assisted alignment,Langmuir-Blodgett assembly,bubble-blown tech.ique,electric/magnetic-field directed assembly,contact/roll printing,knocking-down,etc..With these assembling tech.iques,applications of nanowire/nanotube based devices such.as flexible electronics and sensors have been *** paper delivers an overall review of directed nanowire/nanotube assembling approach.s and analyzes advantages and limitations of each.*** future research.directions have also been discussed.

关键词： Nanowire Nanotube Assembly Shear force Contact printing Dielectrophoresis Microfluidics Nanosystems Nanodevices

ch.racterization of the Ubiquitin E2 Enzyme Variant Gene Family in Arabidopsis

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Journal of Integrative Plant Biology 2007年第1期49卷 120-126页

作者： Yu Zhang Pei Wen On-Sun lau Xing-Wang Deng National Institute of Biological Sciences Zhongguancun Life Science Park Beijing 102206 China Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotech.ology College of Life Sciences Peking University Beijing 100871 China College of Life Sciences Beijing Normal University Beijing 100875 China Department of Molecular Cellular and Developmental Biology Yale University New Haven Connecticut 06520-8104 USA

Ubiquitin E2 enzyme variant （UEV） proteins are similar to ubiquitin-conjugating enzyme （E2） in both sequence and structure, but the lack of a catalytic cysteine residue renders them incapable of forming a thiolester linkage with ubiquitin. While the functional roles of several UEVs have been defined in yeast and animal systems, Arabidopsis COP10, a photomorphogenesis repressor, is the only UEV ch.racterized in plants. Phylogenetic analysis revealed that the eight Arabidopsis UEV genes belong to three subfamilies. The expresslon of those genes is supported by either the presence of ESTs or RT-PCR analysis. We also ch.racterized the other members of the COP10 subfamily, UEV2. Semi-quantitative RT-PCR analysis indicated that the UEV2 transcripts can be detected in most organs of Arabidopsis. Analysis of UEV2：：GUS transgenic lines also showed its ubiquitous expression in nearly all the developmental stages of Arabidopsis. Transient expression analysis indicated that the sGFP-UEV2 fusion protein can localize to both the cytoplasm and nucleus. A T-DNA insertion mutant, uev2-1, which.abolished the transcription of UEV2, displays no visible phenotype. Further, the cop10-4 uev2-1 double mutant exhibits the same phenotype as the cop10-4 mutant in darkness. UEV2 is therefore not functionally redundant with COP10.

关键词： Arabidopsis COP10 E2 gene family ubiquitin UEV