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Chinese Physics letters 2005年第12期22卷 3029-3031页

作者：桑新柱余重秀王葵如 CHU pak l. School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 Optoelectronics Ftesearch Centre City University of Hong Kong Kowloon Hong Kong

Dual wavelength high-frequency chaos based on nonlinear effects is generated in an erbium-doped fibre ring laser, where tunable filters （TFs） are used to select the wavelength. A receiving fibre laser with an open-loop structure is constructed with identical parameters as the transmitting fibre laser. By tuning the TFs and the fibre delay line in the receiving fibre laser, chaos synchronization has been observed at anyone the two wavelengths after the chaos is transmitted over 1 km. It is of far reaching importance to construct the high capacity chaos communication system.

关键词： DOPED FIBER lASERS GENERAlIZED SYNCHRONIZATION RING lASERS DYNAMICS

An Easily Operating Polymer 1×4 Optical Waveguide Switch Matrix Based on Vertical Couplers

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Chinese Physics letters 2007年第6期24卷 1728-1730页

作者： Kaixin Chen pak l Chu Hau Ping Chan Kin S. Chiang Department of Electronic Engineering City University of Hong Kong Kowloon Hong Kong Cotco Holdings ltd Science Park Hong Kong

A three-dimensional （3D） polymer thermo-optic （TO） 1 × 4 waveguide switch matrix based on vertical couplers is demonstrated. It consists of four basic 3D switch units and because of its 3D structure, its construction is compact, only 9 mm in length; moreover, the control logic of the entire switch is very simple, the light signal can be easily switched to any output port by operating only a single switch unit. The finished devices exhibit a switching extinction ratio greater than 21 dB for all of four output ports and the crosstalk between two adjacent output ports is lower than -19 dB. The rise time and the fall time of the switch matrix are 0.8ms and 1.4ms, respectively. The required electrical power to initiate the switching function for M1 switching units is about 50mW.

关键词： FABRICATION DESIGN

Spectrum and Singular Integrals on a New Weighted Function Space

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Acta Mathematica Sinica,English Series 2018年第11期34卷 1692-1702页

作者： Hee Chul pak Young Ja PARK Department of Mathematics Dankook University Dandae-ro 119 Dongnam-gu Cheonan-si Chungnam 31116 Republic of Korea Department of Mathematics Hoseo University Hoeo-ro 79 Asan-si Chungnam 31499 Republic of Korea

We introduce a new function space that is much finer than the classical lebesgue spaces, and investigate the continuity and the discontinuity of the Calderon-Zygmund operators on the new weighted spaces. In order to identify the continuity of singular integrals, we prove an interpolation theorem on the new spaces and propose a concept of the spectrum of base functions.

关键词： Function spaces singular integrals interpolation Calderdn Zygmund operators Holder's inequality l log l

Secure Communication System Based on Chaos in Optical Fibre

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光学学报 2003年第S1期23卷 540-541页

作者： pak l Chu Fan Zhang William Mak Robust lai Optoelectronics Research Centre City Univeristy of Hong Kong Kowloon Hong KongOptoelectronics Research Centre City Univeristy of Hong Kong Kowloon Hong KongOptoelectronics Research Centre City Univeristy of Hong Kong Kowloon Hong KongOptoelectronics Research Centre City Univeristy of Hong Kong Kowloon Hong Kong

1 IntroductionRecently, there have been intense research activities on the study of synchronized chaos generated by fibre lasers and its application to secure communication systems. So far, all studies concentrate on two aspects: (1) the effect of the transmission channel between the transmitter and the receiver has been neglected, and (2) the chaos and the signal are carried by one wavelength. Both theoretical and experimental investigations

关键词： in as on Secure Communication System Based on Chaos in Optical Fibre into been of WDM

Discovery of Zr-based metal-organic polygon:Unveiling new design opportunities in reticular chemistry

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Nano Research 2021年第2期14卷 392-397页

作者： Jiyeon Kim Dongsik Nam Hiroshi Kitagawa Dae-woon lim Wonyoung Choe Department of Chemistry Ulsan National Institute of Science and Technology50 UNIST-gilUlsan 44919Republic of Korea Department of Chemistry Graduate School of ScienceKyoto UniversityKitashirakawa Oiwake-choSakyo-kuKyoto 606-8502Japan Department of Chemistry and Medical Chemistry College of Science and TechnologyYonsei University1 Yonseidae-gilWonjuGangwon-do 26493Republic of Korea

Metal-based secondary building unit and the shape of organic ligands are the two crucial factors for determining the final topology of metal-organic materials.A careful choice of organic and inorganic structural building units occasionally produces unexpected structures,facilitating deeper fundamental understanding of coordination-driven self-assembly behind metal-organic ***,we have synthesized a triangular metal-organic polygon(MOT-1),assembled from bulky tetramethyl terephthalate and Zr-based secondary building ***,the Zr-based secondary building unit serves as an unusual ditopic Zr-connector,toform metal-organic polygon MOT-1,proven to be a good candidate for water adsorption with *** study highlights the interplay of the geometrically frustrated ligand and secondary building unit in controlling the connectivity of metal-organic *** a strategy can be further used to unveil a new class of metal-organic materials.

关键词： reticular chem istry Zr-based metal-organic polygon geometrical frustration ditopic secondary building unit

cDNA-Amplified fragment length polymorphism analysis reveals differential gene expression induced by exogenous MeJA and GA_3 in oilseed rape (Brassica napus l.) flowers

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Journal of Integrative Agriculture 2017年第1期16卷 47-56页

作者： Haksong pak lI Yu-ling Hyenchol Kim JIANG li-xi College of Agriculture and Biotechnology Zhejiang University Department of Genetics College of Life ScienceKIM IL SUNG University

The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins （GA3） to oilseed plants （Brassica napus l.） interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA3 influences the transcriptome at the initial fiowenng stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism （cDNA-AFlP） was analyzed to identify genes whose expression was modulated by application of MeJA and GA3 to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA （50 μmol l-1）, MeJA （100 μmol l-1）, and GA3 （50 μmol l-1）. Overall, 168 transcript-derived fragments （TDFs） were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA3, MeJA, and both GA3 and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.

关键词： Brassica napus l. cDNA-AFlP flower development gibberellic acid methyl jasmonate

Monitoring of non-point source pollutants load from a mixed forest land use

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Journal of Environmental Sciences 2010年第6期22卷 801-805页

作者： Sung Wan Yoon Se woong Chung Dong Geun Oh Jae woon lee Department of Environmental Engineering Chungbuk National University Geum River Environmental Research Center National Institute of Environmental Research

The aim of this study was to determine the unit load of NPS （non-point source） pollutants including organic variables such as BOD （biochemical oxygen demand）, COD （chemical oxygen demand） and DOC （dissolved organic carbon）, nitrogen and phosphorus constituents, and suspended solids （SS） and their event mean concentration （EMC） of runoff flows from a water-shed of mixed forest land use by intensive field experiments. Field monitoring for continuous measurements of rainfall, flow, and water quality was conducted over 12 storm events during 2008-2009 using automated and manual sampling methods. The EMCs of individual runoff event were estimated for each water quality constituent based on the flow rate and concentration data of runoff discharge. The average EMCs of BOD, COD, DOC, SS, TN （total nitrogen）, NH4^＋-N, NO3^--N, TP （total phosphorus）, PO4^3-P from the mixed forest land were 1.794, 3.498, 1.462, 10.269, 0.862, 0.044, 0.634, 0.034, and 0.005 mg/l, respectively. The annual unit loads of BOD, COD, DOC, SS, TN, NH4^＋-N, NO3^--N, TP and PO4^3--P were estimated as 66.9, 133.2, 55.5, 429.8, 36.5, 1.6, 26.9, 1.3 and 0.1 kg/（ha·yr）, respectively. In addition, affecting parameters on the EMCs were investigated by statistic analysis of the field data. As a result, significant correlations with precipitation, rainfall intensity, and total runoff flows were found in most constituents.

关键词： event mean concentration mixed forest land use non-point source pollutant load unit load

Enhancement of matrix metalloproteinases 2 and 9 accompanied with neurogenesis following collagen glycosaminoglycan matrix implantation after surgical brain injury

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Neural Regeneration Research 2018年第6期13卷 1007-1012页

作者： Wei-Cherng Hsu Chun-Hsien Yu woon-Man Kung Kuo-Feng Huang Department of Ophthalmology Taipei Tzu Chi Hospital Buddhist Tzu Chi Medical Foundation School of Medicine Buddhist Tzu Chi University Department of Pediatrics Taipei Tzu Chi Hospital Buddhist Tzu Chi Medical Foundation Division of Neurosurgery Department of Surgery Taipei Tzu Chi Hospital Buddhist Tzu Chi Medical Foundation Department of Exercise and Health Promotion College of Education Chinese Culture University

Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan（CGM）. Matrix metalloproteinases（MMPs） may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan（CGM） following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups：（1） sham operation group： craniotomy only;（2） lesion（l） group： craniotomy ＋ surgical trauma lesion;（3） lesion ＋ CGM（l ＋ CGM） group： CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2（marker of proliferating neural progenitor cells） and matrix metalloproteinases（MMP2 and MMP9） in the lesion boundary zone were assayed and analyzed by immunofluorescence and ElISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2^＋/SOX2^＋ cells and MMP9^＋/SOX2^＋ cells were seen within the lesion boundary zone in the l ＋ CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.

关键词： collagen glycosaminoglycan matrix metalloproteinases surgical brain trauma neurogenesis neural regeneration

Photocatalytic degradation of organic pollutants using green oil palm frond-derived carbon quantum dots/titanium dioxide as multifunctional photocatalysts under visible light radiation

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Chinese Journal of Chemical Engineering 2022年第11期51卷 21-34页

作者： Zeng Wei Heng woon Chan Chong Yean ling Pang lan Ching Sim Chai Hoon Koo lee Kong Chian Faculty of Engineering and Science Universiti Tunku Abdul RahmanSungai Long CampusJalan Sungai LongCheras43000 KajangSelangorMalaysia Centre for Photonics and Advanced Materials Research Universiti Tunku Abdul RahmanSungai Long CampusJalan Sungai LongCheras43000 KajangSelangorMalaysia

The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogendoped carbon quantum dots(NCQDs)and proposed a straightforward in-situ hydrothermal method for the preparation of NCQDs/TiO_(2)*** elemental composition,morphological,structural and optical characteristics of NCQDs/TiO_(2)nanocomposites have been comprehensively *** successful grafting of NCQDs on TiO_(2)matrix was confirmed by the formation of Ti AOAC bond and the electronic coupling between theπ-states of NCQDs and the conduction band of TiO_(2).For the first time,the oil palm frond-derived NCQDs/TiO_(2)was adopted in the photodegradation of methylene blue(MB)under visible-light *** a result,the photocatalytic efficiency of NCQDs/TiO_(2)nanocomposites(86.16%)was 2.85 times higher than its counterpart TiO_(2)(30.18%).The enhanced performance of nanocomposites was attributed to the pivotal roles of NCQDs serving as electron mediator and visiblelight ***,the optimal NCQDs loading was determined at 4 ml while the removal efficiency of NCQDs/TiO_(2)-4 was the highest at a catalyst dosage of 1 g.l^(-1)under alkaline *** research work is important as it proposed a new insight to the preparation of biomass-based NCQDs/TiO_(2)using a facile synthetic method,which offers a green and sustainable water remediation technology.

关键词： Oil palm frond biomass N-doped carbon quantum dots Titanium-dioxide In-situ hydrothermal Visible light photocatalysis Methylene blue