检索结果-南通市图书馆

Q-switched giant pulsed erbium-doped all-fiber laser with V_(2)ZnC MAX phase saturable absorber

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第6期20卷 321-329页

作者： kawther M Musthafa Azura Hamzah ooi Wei Ling Ahmad Haziq Aiman Rosol Norliza Mohamed Sulaiman Wadi Harun Malaysia-Japan International Institute of technology Universiti Teknologi MalaysiaKuala Lumpur 54100Malaysia Razak Faculty of technology and Informatics Universiti Teknologi MalaysiaKuala Lumpur 54100Malaysia Department of Electrical Engineering University of MalayaKuala Lumpur 50603Malaysia1

MXenes,drawn from MAX phases,are special two-dimensional substances with numerous advantages in nonlinear optics,specifically in giant and ultrashort pulsed-laser ***_(3)C_(2)t_(x)and ti_(2)Ct_(x)nanosheets however rapidly deteriorate under ambient conditions,limiting their *** paper demonstrates how excellent modulation depth of one of the MAX phase compounds vanadium zinc carbide(V_2ZnC)makes it a brilliant saturable absorber(SA)in passively Q-switched all-fiber pulsed lasers,integrated such that a 16.73-μm V_(2)ZnC-polyvinyl alcohol(PVA)thin film acts as SA in the *** and non-saturable absorptions were found to be 13.2%and 10.47%,while saturation optical intensity and modulation depth were 6.25 k W/cm^(2)and 12.43%,respectively,illustrating the optical *** superiority of MAX-PVA,fabricated in four distinct ratios,was demonstrated by the fact that it self-starts a giant pulsed laser at pump power as low as 22.5 mW and firmly accomplished 120.6 kHz repetition rate with a pulse width of 2.08μ*** is a fine SA for the use of pulsed-laser production using all-fiber laser due to fabrication simplicity and great optical,thermophysical,and mechanical qualities.

关键词： MAX Q-switched giant pulsed erbium-doped all-fiber laser with V_(2)ZnC MAX phase saturable absorber

Nonlinear optics on silicon-rich nitride--a high nonlinear figure of merit CMOS platform[Invited]

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2018年第5期6卷 I0075-I0091页

作者： D.t.H.tAN k.J.A.ooi D.k.t.NG Photonics Devices and Systems Group Singapore University of Technology and Design8 Somapah Rd.Singapore 487372Singapore Data Storage Institute Agency for ScienceTechnology and Research(A*STAR)2 Fusionopolis Way#08-01 InnovisSingapore 138634Singapore

CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. Silicon-based platforms have been prolific amongst the suite of advanced nonlinear optical signal processes demonstrated to date. these include crystalline silicon, amorphous silicon, Hydex glass, and stoichio- metric silicon nitride. Residing between stoichiometric silicon nitride and amorphous silicon in composition, silicon-rich nitride films of various formulations have emerged recently as promising nonlinear platforms for high nonlinear figure of merit nonlinear optics. Silicon-rich nitride films are compositionally engineered to create bandgaps that are sufficiently large to eliminate two-photon absorption at telecommunications wavelengths while enabling much larger nonlinear waveguide parameters （5x-500x） than those in stoichiometric silicon uitride. this paper reviews recent developments in the field of nonlinear optics using silicon-rich nitride platforms, as well as the outlook and future opportunities in this burgeoning field.

关键词： Nonlinear optics silicon-rich nitride a high Nonlinear figure of merit CMOS platform

一种模拟堆石料的二维多边形离散单元法及程序

在线全文

学校读者我要写书评

暂无评论

岩土力学 2017年第3期38卷 883-892页

作者：罗滔 ooi E t CHAN A H C 傅少君武汉大学土木建筑工程学院湖北武汉430072 澳大利亚联邦大学工程与计算机信息学院塔斯马尼亚大学工程信息与计算机技术学院

在考虑堆石料真实颗粒形状的基础上,将每个颗粒用一个多边形离散单元表示,基于一种线性搜索算法对多边形-多边形之间的接触详情进行检索计算,引入基于势能原理的法向多边形-多边形接触模型及切向库仑摩擦模型,形成了一种多边形离散元计... 详细信息

在考虑堆石料真实颗粒形状的基础上,将每个颗粒用一个多边形离散单元表示,基于一种线性搜索算法对多边形-多边形之间的接触详情进行检索计算,引入基于势能原理的法向多边形-多边形接触模型及切向库仑摩擦模型,形成了一种多边形离散元计算方法,并开发了相应的PDEM程序。可以从颗粒尺度层面展示颗粒之间的相互作用以及每个颗粒的位移和转动,帮助进一步揭示颗粒的细观特性(形状、大小、材料特性等)对堆石料的宏观强度和变形的影响。最后采用PDEM程序对某粗粒料的二维模型试验进行了数值模拟,得到了与室内试验一致的应力变形规律,展现了其方法和程序用于研究堆石料的有效性。

关键词：堆石料离散单元法接触检索接触模型 PDEM 双轴试验

一种模拟堆石料颗粒破碎的离散元-比例边界有限元结合法

在线全文

学校读者我要写书评

暂无评论

岩土力学 2017年第5期38卷 1463-1471页

作者：罗滔 E.t.ooi A.H.C Chan 傅少君武汉大学土木建筑工程学院湖北武汉430072 澳大利亚联邦大学科学与技术学部塔斯马尼亚大学工程信息与交流技术学院

试验研究和数值模拟都表明,颗粒破碎对颗粒岩土材料的宏观力学响应具有重要的影响。结合离散元与比例边界有限元法,提出一种用于研究堆石料颗粒破碎行为的新的数值计算方法,可以将两种方法各自的优势同时发挥出来。离散单元法将被用于... 详细信息

试验研究和数值模拟都表明,颗粒破碎对颗粒岩土材料的宏观力学响应具有重要的影响。结合离散元与比例边界有限元法,提出一种用于研究堆石料颗粒破碎行为的新的数值计算方法,可以将两种方法各自的优势同时发挥出来。离散单元法将被用于求解颗粒的运动以及相互作用。在每一个时间步尾,采用比例边界有限单元法计算颗粒内部的应力分布。比例边界有限单元法可以仅用一个任意边数的多边形来描述一个颗粒,大大节约应力计算的成本。当应力状态确定之后,Hoek-Brown准则将被引入用于确定颗粒内部的破坏点,当破坏点达到一定的比例时,即视为这个颗粒将破坏。为简化起见,假设破坏路径为直线,如果破坏发生,则该颗粒一分为二,各个新的颗粒将直接参与离散元和比例边界有限元的计算。该方法无需预定义任何子颗粒或网格重划分。最后以一个简单的双轴试验的模拟展现方法的可行性。

关键词：堆石料离散单元法比例边界有限单元法颗粒破碎 Hoek-Brown准则双轴试验

Broadband strong optical dichroism in topological Dirac semimetals with Fermi velocity anisotropy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第7期29卷 128-134页

作者： J Lim k J A ooi C Zhang L k Ang Yee Sin Ang Science Math and TechnologySingapore University of Technology and DesignSingapore School of Energy and Chemical Engineering Xiamen University MalaysiaSelangor Darul Ehsan 43900Malaysia College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005China School of Physics University of WollongongNorthfields AvenueNew South Wales 2522Australia

Prototypical three-dimensional(3D)topological Dirac semimetals(DSMs),such as Cd3As2 and Na3Bi,contain electrons that obey a linear momentum-energy dispersion with different Fermi velocities along the three orthogonal momentum *** being extensively studied in recent years,the inherent Fermi velocity anisotropy has often been neglected in the theoretical and numerical studies of 3D *** this omission does not qualitatively alter the physics of light-driven massless quasiparticles in 3D DSMs,it does quantitatively change the optical coefficients which can lead to nontrivial implications in terms of nanophotonics and plasmonics *** we study the linear optical response of 3D DSMs for general Fermi velocity values along each *** the signature conductivity-frequency scaling,σ(ω)∝ω,of 3D Dirac fermion is well-protected from the Fermi velocity anisotropy,the linear optical response exhibits strong linear dichroism as captured by the universal extinction ratio scaling law,Λi j=(vi/v j)^2(where i=j denotes the three spatial coordinates x,y,z,and vi is the i-direction Fermi velocity),which is independent of frequency,temperature,doping,and carrier scattering *** Cd3As2 and Na3Bi3,an exceptionally strong extinction ratio larger than 15 and covering a broad terahertz window is *** findings shed new light on the role of Fermi velocity anisotropy in the optical response of Dirac semimetals and open up novel polarization-sensitive functionalities,such as photodetection and light modulation.

关键词： topological Dirac semimetal optical anisotropy linear dichroismn linear response theory

Antiviral activities of extracts from Hong kong seaweeds

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第12期9卷 969-976页

作者： Hui WANG Engchoon Vincent ooi Put O. ANG Jr Medical College Jinan University Guangzhou 510632 China Department of Biology the Chinese University of Hong Kong Shatin N. T. Hong Kong China

We extracted six Hong kong brown seaweed species with hot water for their antiviral properties. the cytotoxicity and antiviral activity of these extracts were tested by Mtt [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenlytetrezolium bromide] method, cytopathic effect reduction assay, and plaque reduction assay. the antiviral effect was further determined by flow cytometric analysis. the results showed that most of these extracts inhibited the propagation of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) standard strains with very low cytotoxicity to the host cells. the extracts of Hydroclathrus clathratus and Lobophora variegata showed more potential anti-HSV activities than the extracts of the other four seaweeds. they also had moderate anti- respiratory syncytial virus (RSV) activities but could not inhibit influenza A virus. Hydroclathrus clathratus was further extracted by diluted acid and alkali and the antiviral effects of the extracts were also detected. the result showed that the hot water extract contained the main carbohydrate components that exhibited the antiviral activities against various strains of HSV, including the acyclovir-resistant strain. HI-3, a compound fractionated from this hot water extract, showed a dose-dependent anti-HSV activity in flow cytometric analysis and plaque reduction assay.

关键词： Hong kong seaweed Hydroclathrus clathratus Antiviral activity Herpes simplex virus (HSV) Flow cytometry

Do introduced honeybees affect seed set and seed quality in a plant adapted for bird pollination?

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2017年第4期10卷 721-729页

作者： Amy-Marie Gilpin Justin C.Collette Andrew J.Denham Mark k.J.ooi David J.Ayre Centre for Sustainable Ecosystem Solutions School of Biological SciencesUniversity of WollongongNorthfields AvenueWollongongNSW 2522Australia NSW Department of Premier and Cabinet Office of Environment and HeritagePO Box 1967HurstvilleNSW 2220Australia Centre for Ecosystem Science School of BiologicalEarth and Environmental SciencesUniversity of New South WalesSydneyNSW 2052Australia

Aims Worldwide,evidence suggests that exotic pollinators can disrupt plant mating ***,few studies have determined if pol-lination by the honeybee Apis mellifera(the world’s most widely introduced pollinator)reduces offspring quality when compared with pollination by native *** Australian Proteaceae provides an excellent opportunity to test the impact of honeybees in pol-lination systems that are adapted to birds and non-flying *** We compared the frequency of flower visitation and foraging behav-iour of birds and insects within seven populations of Banksia *** ericifolia is hermaphroditic and has large nectar-rich,orange inflorescences typical of bird and mammal pollinated *** a subset of the study populations,we compared the qual-ity of seed produced via an exclusion treatment(that only allowed invertebrates to access flowers)with an open-pollination treatment(potentially visited by mammals,birds and invertebrates),by meas-uring seed weight,germination rates(t50),percent germination,seedling height after 14 days since the emergence of the cotyledon and time to emergence of the *** Findings Apis mellifera was the only apparent insect pollinator and the most frequent flower visitor,while the open treatment inflorescences were also frequently visited by avian pollinators,primarily hone-yeater *** foraging behaviour of honeybees and honeyeat-ers showed striking differences that potentially affect patterns of pollen *** made significantly greater proportions of within *** plant movements and only 30%(n=48)of honeybees foraged for pollen(nectar foragers carried no pollen)whilst all birds were observed to contact both stigmas and anthers when foraging for *** these fundamental differences in behaviour,there was little effect of treatment on seed set or *** data show that while honeybees appear to alter patterns of pollen transfer within *** popu

关键词： Apis mellifera Banksia ericifolia Proteaceae seedling performance seed vigour

Apoptotic and cytostatic actions of maslinic acid in colorectal cancer cells through possible Ikk-β inhibition

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of tropical Biomedicine 2021年第3期11卷 122-131页

作者： kai Xin ooi Menaga Subramaniam Lai Yen Fong Hoe Han Goh Soo Beng Alan khoo Yang Mooi Lim Centre for Cancer Research Faculty of Medicine and Health SciencesUniversiti Tunku Abdul RahmanLOT PT 21144.Jalan Sungai LongBandar Sungai LongCheras 43000 KajangSelangorMalaysia Department of Pre-Clinical Sciences Faculty of Medicine and Health SciencesUniversiti Tunku Abdul RahmanLOT PT 21144.Jalan Sungai LongBandar Sungai LongCheras 43000 KajangSelangorMalaysia Institute of Systems Biology Universiti Kebangsaan Malaysia43600 BangiSelangor Darul EhsanMalaysia Molecular Pathology Unit Cancer Research CentreInstitute for Medical ResearchKuala LumpurMalaysia

Objective:to explore the anti-cancer activity of maslinic acid against colorectal cancer(CRC)cell lines and its possible ***:the inhibitory effect of maslinic acid was screened against five CRC cell lines(Ht-29,HCt 116,SW480,SW48,and LS 174 t)via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide *** and cell cycle analyses were carried out using annexinⅤ-FItC/propidium iodide staining and propidium iodide staining,respectively and subjected to fluorescence-activated cell sorting *** expression studies of inhibitor ofκB kinase-β(Ikk-β),checkpoint kinase 1(Chk1)and cyclin D1 were conducted using the JESS ***:Maslinic acid exhibited growth inhibitory effect in a doseand time-dependent manner in Ht-29 and HCt 116 cell lines.A more prominent apoptosis induced by maslinic acid was observed in HCt 116 cell ***,in Ht-29 cell line,maslinic acid induced cell cycle arrest by inhibiting the G1-S transition,which was accompanied by the downregulation of cyclin *** expression of unphosphorylated Ikk-βprotein was increased in both(Ht-29 and HCt 116)cell lines after maslinic acid ***:Maslinic acid inhibits the growth of Ht-29 and HCt 116 cells in a different manner,induces cell cycle arrest in Ht-29 cells and causes apoptosis in HCt 116 cells partially via NF-κB pathway inhibition.

关键词： Maslinic acid Colorectal cancer Apoptosis Cell cycle arrest NF-κB pathway Ikk-β

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

堆石体宏细观力学特性演化机制的离散元模拟

武汉大学学报（工学版） 2018年第7期51卷 607-612页

作者：罗滔李刚 ooiE t CHAN A HC 傅少君邹维列西京学院陕西省混凝土结构安全与耐久性重点实验室陕西西安710123 澳大利亚联邦大学工程与计算机信息学院澳大利亚巴拉腊特3350 塔斯马尼亚大学工程信息与计算机技术学院澳大利亚霍巴特7000 武汉大学土木建筑工程学院湖北武汉430072

以具有尖角的堆石颗粒材料为研究对象,采用自主开发的多边形离散单元法程序PDEM对其在双轴压缩试验过程中的宏-细观力学特性及变形破坏机制进行系统分析.根据数值试验中试样在不同围压下应力及变形的发展,从颗粒运动角度探讨试样宏观应... 详细信息

以具有尖角的堆石颗粒材料为研究对象,采用自主开发的多边形离散单元法程序PDEM对其在双轴压缩试验过程中的宏-细观力学特性及变形破坏机制进行系统分析.根据数值试验中试样在不同围压下应力及变形的发展,从颗粒运动角度探讨试样宏观应力应变剪胀特性演化的细观机制;细观组构与宏观应力变形的发展之间具有同步性,反映试样宏细观演化的统一性;通过对颗粒细观各向异性的统计分析,揭示颗粒间摩擦及咬合作用是维持细观力学结构相对稳定的重要因素;通过对力链网络的形态演化分析,发现试样大主应力方向与各向异性主方向一致,力链密集程度随压缩过程先上升后下降,试样孔隙度也随之先减小后增大,反映了试样宏观先减缩后剪胀的特性.

关键词：堆石体多边形离散单元法双轴压缩应力-应变-剪胀宏细观机制