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Synthesis and properties of poly(1-phenyl-1-octyne)s containing stereogenic and chromophoric pendant groups

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Science China Chemistry 2009年第10期52卷 1691-1702页

作者： lam jacky w.Y. JIM Cathy K.w. KwOK Hoi Sing Department of Chemistry The Hong Kong University of Science & Technology Center for Display Research The Hong Kong University of Science & Technology

poly(1-phenyl-1-octyne)s containing different stereogenic and chromophoric pendants {-[(C6H13)C= C(C6H4-p-CO2-R)] n -R = [(1S)-endo]-(?)-borneyl (p3), (1R,2S,5R)-(?)-menthyl (p4), -C6H4-p-(1R,2S,5R)-(?)-menthyl (p5), 2-napthyl (p6), 4-biphenylyl (p7)} have been designed and synthesized. The polymers are prepared in moderate yields by wCl6-ph4Sn and possess high molecular weights (M w up to 64000). The structures and properties of the polymers are characterized and evaluated by NMR, TGA, UV, CD, pL, and EL analyses. All the polymers are thermally stable and their temperatures for 5% weight loss locate in the range of 300 to 416°C under nitrogen. The energy band gaps of all the polymers are ～3.0 eV. polymers p4 and p5 show CD absorptions associated with the helicity of the polymer segments. Excitation of the THF solutions of p3–p7 by UV irradiation gives strong blue lights of ～485 nm with quantum yields higher than 20%. The thin films of the polymers also emit in the same spectral region, indicative of little aggregation-caused quenching of light emission. Multilayer EL devices with a configuration of ITO/polymer:pVK/BCp/Alq3/LiF/Al are constructed, which emit blue lights of ～487 nm. The maximum luminance and external quantum efficiency vary with the pendant groups, with p6 exhibiting the highest external quantum efficiency of 0.16%. The spectra stability of the EL devices is outstanding and the EL peak maximum experiences little change with the applied voltage.

关键词： chiral photoluminescence polyacetylene electroluminescence helicity

Restriction of Intramolecular Motion(RIM):Investigating AIE Mechanism from Experimental and Theoretical Studies

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Chemical Research in Chinese Universities 2021年第1期37卷 1-15页

作者： ZHANG Jianyu ZHANG Haoke lam jacky w.Y. TANG Ben Zhong Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and ReconstructionInstitute for Advanced Studyand Department of Chemical and Biological EngineeringThe Hong Kong University of Science&TechnologyClear Water BayKowloonHong KongP.R.China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027P.R.China Center for Aggregation-Induced Emission SCUT-HKUST Joint Research InstituteState Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou510640P.R.China Guangzhou Development District AIE InstituteGuangzhou510530P.R.China

Mechanistic studies promote scientific development from phenomena to ***-induced emission(AIE),as an unusual photophysical phenomenon,builds the bridge between molecular science and aggregate *** the twenty-year development of AIE,restriction of intramolecular motion(RIM)has been verified as the working mechanism of AIE *** this review,these mechanistic works about RIM are summarized from experimental and theoretical ***,the experimental studies are introduced from three parts:external rigidification,structural modification and structural *** the theoretical part,calculations on the low-frequency motion of AIEgens have been performed to prove the RIM *** virtue of the theoretical calculations,some new mechanisms are proposed to supplement the RIM,such as restriction of access to conical intersection,suppression of Kasha transition,restriction of access to dark state,*** is foreseeable that the RIM mechanism will unify the photophysical theories for both molecules and aggregates,and inspire more progress in aggregate science.

关键词： Aggregation-induced emission(AIE) Restriction of intramolecular motion photophysical mechanism Aggregate science

Crystalline Behavior and Structure of a Liquid Crystal Com- pound, 5-{[4＇-（（（pentyl）oxy）-4-biphenylyl）carbonyl]oxy}- 1 -pentyne

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Chinese Journal of Chemistry 2011年第4期29卷 631-638页

作者：刘雷静李杲周恩乐 lam,jacky wing Yip 唐本忠 State Key Laboratory of Supramolecular Structure and Materials Jilin University Changchun Jilin 130012 China State Key Laboratory of polymer physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Graduate School of Chinese Academy of Sciences Changchun Jilin 130022 China Department of Chemistry Hong Kong University of Science & Technology Clear Water Bay Kowloon Hong Kong China

Single crystals of two liquid crystal compounds, 5-{[4＇-（（（pentyl）oxy）-4-biphenylyl）carbonyl]oxy}-1-pentyne （A3EO5） and 5-{[（4＇-nonyloxy-4-biphenylyl）carbonyl]oxy}-1-pentyne （A3EO9）, have been prepared by solution growth technique. The morphologies and structures of A3EO5 and A3EO9 crystals were investigated by wide angle X-ray diffraction （wXRD）, atom force microscope （AFM） and transmission electron microscope （TEM）. In contrast to the same series of compounds which have a longer alkyl tail, 5-{[（4＇-heptoxy-4-biphenylyl）carbonyl]oxy}-1-pentyne （A3EO7）, 5-{[（4＇-heptoxy-4-biphenylyl）oxy]carbonyl}-1-pentyne （A3E＇O7） and A3EO9, A3EO5 shows strikingly different crystalline behavior. The former three compounds have only one crystal form, whereas A3EO5 exhibits polymorphism. Specifically, A3EO5 crystals grown from toluene solution show two crys- tal forms. The first one is crystal I which adopts a monoclinic p112/m space group with unit cell parameters of a= 5.79A, b=8.34A, c=43.92/k, y=96°, and the other one is crystal II which adopts a monoclinic p112 space group with unit cell parameters of a=5.55A, b=7.38A, c=31.75 ]k, y=94°. when using dioxane as the solvent to grow A3EO5 crystal, we can selectively obtain crystal Ⅰ. A3EO5 melt-grown crystals also have two crystal forms which derive from crystal I and crystal Ⅱ, respectively. The different crystalline behavior of the compounds should correlate with their different electron dipole moment resulting from the different length of alkyl tail.

关键词： crystal growth crystal morphology crystal structure electron diffraction single crystal

SYNTHESIS AND pHOTOLUMINESCENCE OF AN ANTHRACENE-CONTAINING HYpERBRANCHED pOLY(ARYLENEETHYNYLENE)

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Chinese Journal of polymer Science 2005年第6期23卷 665-669页

作者： Yong-qiang Dong Zhen Li jacky w. Y. lam Yu-ping Dong Xin-de Feng Ben-zhong Tang Department of polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Department of Chemistry Center for Display Research The Hong Kong University of Science ＆ Technology Clear Water Bay Kowloon Hong Kong China

A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, pL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.

关键词： Hyperbranched polymer Cross-coupling Blue light emission

1-((12-Bromododecyl)oxy)-4-((4-(4-pentylcyclohexyl)phenyl)ethynyl) benzene: Liquid crystal with aggregation-induced emission characteristics

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Science China Chemistry 2013年第9期56卷 1191-1196页

作者： CHEN YaFei LIN JieSheng YUAN wangZhang YU ZhenQiang lam jacky.w.ngy.p TANG Ben Zhong Shenzhen Key Laboratory of Functional polymers School of Chemistry and Chemical EngineeringShenzhen University National Institutes for Food and Drug Control School of Chemistry and Chemical engineering Shanghai Jiao Tong University Department of Chemistry The Hong Kong University of Science & Technology

The luminescent liquid crystals (LLCs) are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs. Herein, we developed a new strategy of applying aggregation-induced emission (AIE) phenomenon to the molecular design of LCs towards LLCs. In this report, a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by 1H, 13C NMR, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) high-resolution mass spectra. The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (pOM). The crystal structure was obtained by X-ray diffraction crystallography with p1 space group. Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic, smectic C and smectic B phase.

关键词： aggregation-induced emission tolane liquid crystal phase behavior

Occurrence and fate of endogenous steroid hormones,alkylphenol ethoxylates, bisphenol A and phthalates in municipal sewage treatment systems

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Journal of Environmental Sciences 2017年第11期29卷 49-58页

作者： Qian wu James C.w.lam Karen Y.Kwok Mirabelle M.p.Tsui paul K.S.lam State Key Laboratory in Marine pollution (SKLMp) Department of Biology and Chemistry Research Centre for the Oceans and Human Health Shenzhen Key Laboratory for Sustainable Use of Marine Biodiversity City University of Hong Kong Department of Science and Environmental Studies The Education University of Hong of Kong

Steroid hormones, alkylphenol ethoxylates（ApEOs） and phthalic acid esters（pAEs） are emerging endocrine disrupting chemicals（EDCs） that can interfere with the endocrine function in organisms at low concentrations. The occurrence, distribution behavior, removal rate and the fate of 31 target EDCs in sewage treatment plants, which consist of various treatment facilities and receiving water in Hong Kong, were investigated. Estrone,nonylphenol-di-ethoxylate and diethyl phthalate were found to be dominant in each group of influent samples with concentrations ranging from 11–33, 747–3945 and 445–4635 ng/L,respectively. Conversely, progesterone, nonylphenol-mono-ethoxylate and bis（2-ethylhexyl）phthalate were the most abundant in dewatered sludge, with concentrations ranging from 0.9–237, 75–19,743 and 4310–37,016 ng/g（dry weight）. The removal rates of primary sedimentation and disinfection approaches were lower than 30% for most of the chemicals,while those of activated sludge and reverse osmosis were greater than 80% for more than two-thirds of the compounds, noticeably decreasing the estrogenic risk of sewage discharged into the environment. Steroid hormones were removed via biological degradation, while some ApEOs and pAEs adsorbed to the sludge. Victoria Harbor poses a low to medium estrogenic risk mainly contributed by estrone and estradiol and deserves attention.

关键词： Endocrine disruptor Steroid hormone Alkylphenol ethoxylate phthalic acid ester Risk assessment

Endohepatology:Arrival at the frontier of interventional endosonography

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world Journal of Gastroenterology 2024年第18期30卷 2397-2401页

作者： Shane p Selvanderan Eric lam Neal Shahidi Department of Medicine University of British ColumbiaVancouver V6Z 1Y6BCCanada

Endohepatology describes the emerging field where diagnostic and therapeutic endoscopic ultrasound(EUS)are used for the diagnosis and management of liver disease and its *** this editorial we comment on the article by Gadour et *** spectrum of EUS-guided procedures includes liver parenchymal and lesional biopsy,abscess drainage,treatment of focal liver lesions,diagnosis of portal hypertension and management of gastric *** data suggest that the application of EUS to hepatology is technically feasible and safe,heralding the arrival at a new frontier for *** data,specifically randomised trials comparing EUS to interventional radiology techniques,and continued partnership between endoscopy and hepatology are required to see this field establish itself outside expert tertiary centres.

关键词： Cancer Cirrhosis Endoscopy Endoscopic ultrasound Liver disease

Fast compression of computer-generated holographic images based on a GpU-accelerated skip-dimension vector quantization method

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Chinese Optics Letters 2013年第5期11卷 28-32页

作者： Y.K.lam w.C.Situ p.w.M.Tsang Department of Electronic Engineering City University of Hong Kong

A method for fast and low bit-rate compression of digital holograms based on a new vector quantization （VQ） method known as the skip-dimension VQ （SDVQ） is proposed. Briefly, a complex hologram is converted into a real off-axis hologram, and partitioned into a set of image vectors. The image vectors are passed into a graphic processing unit （GpU）, and compressed through SDVQ into a set of code indices considerably smaller in data size than the source hologram. Experimental evaluation reveals that our scheme is capable of compressing a digital hologram to a compression ratio of over 500 times, in approximately 20-22 ms.

关键词： GpU Fast compression of computer-generated holographic images based on a GpU-accelerated skip-dimension vector quantization method VQ

5-[4′-正庚基-氧-联苯基-4-氧-羰基]基-1-正戊炔的晶体结构研究

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高等学校化学学报 2005年第7期26卷 1366-1368,M010页

作者：刘雷静耿建新周云春尹丽李杲周恩乐 jacky lam wing Yip 唐本忠中国科学院研究生院长春应用化学研究所高分子物理与化学国家重点实验室长春130022 香港科技大学化学系

The crystal structure of 5-{[(4′-heptoxy-biphenylyl-4-yl)oxy]carbonyl}-1-pentyne({A3E′O7}) was investigated by wide angle X-ray diffraction(wAXD), transmission electron microscope(TEM) and atom force microscope(AFM). The structures of A3E′O7 solution-crystal and melt-crystal are the same. The crystals belong to the monoclinic p112/m space group, the cell parameters are {a0.589 nm}, b0^771 nm, c4.75 nm, αβ90° and γ93.8°, the calculated cell density is {1.167 g/cm+3}.

关键词：晶体结构 5-[4′-正庚基-氧-联苯基-4-氧-羰基]基-1-正戊炔透射电镜 X射线衍射