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Photonics Research 2023年第2期11卷 181-188页

作者： KUNHAO j. DI LIN IAN A. davidSON SIYI WANG j.EL CARPENTER YOSHIMICHI AMMA YONGMIN j.NG MASSIMILIANO GUASONI david j. richardson Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK Institute of Advanced Photonics Technology School of Information EngineeringGuangdong University of TechnologyGuangzhou 510006China Guangdong Provincial Key Laboratory of Photonics Information Technology Guangdong University of TechnologyGuangzhou 510006China School of Information Technology and Electrical Engineering The University of QueenslandBrisbaneQLD 4072Australia Fuj.kura Ltd. Chiba 285-8550Japan

Higher-order Poincarésphere(HOPS) beams with spatially variable polarization and phase distributions are opening up a host of unique applications in areas ranging from optical communication to ***, the flexible generation of these beams with high peak power from compact laser systems remains a challenge. Here, we demonstrate the controlled generation of HOPS beams based on coherent beam combination from an Yb-doped multicore fiber(MCF) amplifier. Using a spatial light modulator to adaptively adj.st the wavefront and polarization of the signals seeded into the individual cores of the MCF various structured beams(including cylindrical vector beams and first-and second-order vortex beams) were generated with peak powers up to 14 k W for ~92 ps pulses.

关键词： amplifier polarization fiber

Highly Efficient L-Band Fibre -DFB Lasers

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光学学报 2003年第S1期23卷 379-380页

作者： Morten Ibsen david j. richardson david N. Payne ORC - University of Southampton Southampton SO17 1BJ United Kingdom. Also with Southampton Photonics Ltd. Southampton SO16 4NS United Kingdom.ORC - University of Southampton Southampton SO17 1BJ United Kingdom. Also with Southampton Photonics Ltd. Southampton SO16 4NS United Kingdom.ORC - University of Southampton Southampton SO17 1BJ United Kingdom. Also with Southampton Photonics Ltd. Southampton SO16 4NS United Kingdom.

A more than 12 mW highly efficient fibre-DFB laser operating at 1618.3 nm is fabricated and characterised. Its high-power, low-noise and single-polarisation characteristics make it very suitable WDM-source for L-band ... 详细信息

关键词： DFB Lasers high in for Highly Efficient L-Band Fibre WDM RIN

Multi-Wavelength Optical Packet Routing Technologies Based on Superstructured Fiber Bragg Gratings

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光学学报 2003年第S1期23卷 699-700页

作者： Benn C. Thomsen Peh C. Teh Morten Ibsen david j. richardson Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.

A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstr... 详细信息

关键词： WDM in of as OCL that Multi-Wavelength Optical Packet Routing Technologies Based on Superstructured Fiber Bragg Gratings on

Tuning electronic properties of cobalt phthalocyanines for oxygen reduction and evolution reactions

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Science China Chemistry 2024年第1期67卷 398-407页

作者： j.anlin j.ang Zhen Liu Shuaij.n Pan Xinnian Xia Bing Qin Yang Hu Xuxu Wang j.amin Lan Yu Gu Encai Ou Weij.an Xu j.seph j.richardson Rui Guo SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China College of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410128China Department of Chemical Engineering The University of MelbourneParkville 3010Australia College of Environmental Science and Engineering Hunan UniversityChangsha 410082China School of Engineering RMIT UniversityMelbourneVictoria 3001Australia

Metal–phthalocyanines are a class of catalytically active materials promising in energy conversion and storage fields(e.g.,electrocatalysis).However,understanding and controlling the electrochemical properties in metal-phthalocyanine systems is ***,we elucidate the electrocatalytic origins of a series of cobalt-phthalocyanine molecular catalysts and finetune their electronic properties at the atomic level,both experimentally and *** interactions between the cobalt center and the local coordination environment are regulated by introducing either electron-donating or electron-withdrawing groups on the phthalocyanine ligand,and the spin-orbit splitting of cobalt is increased by~0.15 eV compared with the nonsubstituted ***,the aminated cobalt phthalocyanine-based electrocatalysts exhibit low free energies in the ratedetermining steps of the oxygen reduction(-1.68 eV)and oxygen evolution reactions(0.37 eV).This contributes to the high electrocatalytic activity(e.g.,a halfwave potential of 0.84 V and an overpotential of 0.30 V at 10 mAcm^(-2)),featuring a high selectivity of a four-electron pathway(i.e.,a negligible by-product of hydrogen peroxide).These catalysts also exhibit exceptional kinetic current density(Tafel slope of 100 mV dec^(-1))in oxygen reduction reactions,in addition to a superior power density(158 mWcm^(-2))and a high cycling stability(>1,300 cycles)in Zn-air batteries,outperforming the commercial Pt/C and/or RuO2counterparts.

关键词： interfacial wettability molecular catalysts carbon nanotubes density functional theory electrochemistry

Disinfection byproducts in chlorinated or brominated swimming pools and spas: Role of brominated DBPs and association with mutagenicity

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j.urnal of Environmental Sciences 2022年第7期34卷 253-263页

作者： Hannah K.Liberatore Eric j.Daiber Sridevi A.Ravuri j.dith E.Schmid Susan D.richardson david M.DeMarini Air Methods and Characterization Division Center for Environmental Measurement and ModelingU.S.Environmental Protection AgencyResearch Triangle ParkNC 27711USA Student Services Authority U.S.Environmental Protection AgencyNational Exposure Research LaboratoryAthensGA 30605USA National Health and Environmental Effects Research Laboratory U.S.Environmental Protection AgencyResearch Triangle ParkNC 27711USA Department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

Although the health benefits of swimming are well-documented, health effects such as asthma and bladder cancer are linked to disinfection by-products(DBPs) in pool water. DBPs are formed from the reaction of disinfectants such as chlorine(Cl) or bromine(Br) with organics in the water. Our previous study(Daiber et al., Environ. Sci. Technol. 50, 6652;2016) found correlations between the concentrations of classes of DBPs and the mutagenic potencies of waters from chlorinated or brominated swimming pools and spas. We extended this study by identifying significantly different concentrations of 21 individual DBPs in brominated or chlorinated pool and spa waters as well as identifying which DBPs and additional DBP classes were most associated with the mutagenicity of these waters. Using data from our previous study, we found that among 21 DBPs analyzed in 21 pool and spa waters, the concentration of bromoacetic acid was significantly higher in Brwaters versus Cl-waters, whereas the concentration of trichloroacetic acid was significantly higher in Cl-waters. Five Br-DBPs(tribromomethane, dibromochloroacetic acid, dibromoacetonitrile, bromoacetic acid, and tribromoacetic acid) had significantly higher concentrations in Br-spa versus Cl-spa waters. Cl-pools had significantly higher concentrations of ClDBPs(trichloroacetaldehyde, trichloromethane, dichloroacetic acid, and chloroacetic acid), whereas Br-pools had significantly higher concentrations of Br-DBPs(tribromomethane, dibromoacetic acid, dibromoacetonitrile, and tribromoacetic acid). The concentrations of the sum of all 4 trihalomethanes, all 11 Br-DBPs, and all 5 nitrogen-containing DBPs were each significantly higher in brominated than in chlorinated pools and spas. The 8 Br-DBPs were the only DBPs whose individual concentrations were significantly correlated with the mutagenic potencies of the pool and spa waters. These results, along with those from our earlier study, highlight the importance of Br-DBPs in the muta

关键词： Swimming pools Hot tubs Mutagenicity Disinfection byproducts Spas

A balancing act: Optimizing free chlorine contact time to minimize iodo-DBPs, NDMA, and regulated DBPs in chloraminated drinking water

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j.urnal of Environmental Sciences 2022年第7期34卷 315-325页

作者： Matthew A.Bloodgood Sridevi Anduri Chowdary Eric j.Daiber Honglan Shi Caroline O.Granger Susan D.richardson Student Services Authority U.S.Environmental Protection AgencyNational Exposure Research LaboratoryAthensGA 30605USA Department of Chemistry Missouri University of Science and TechnologyRollaMO 65409USA Department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

Many drinking water treatment plants in the U.S. have switched from chlorination to chloramination to lower levels of regulated trihalomethane(THM) and haloacetic acid(HAA) disinfection byproducts(DBPs) in drinking water and meet the current regulations. However, chloramination can also produce other highly toxic/carcinogenic, unregulated DBPs: iodoacids, iodo-THMs, and N-nitrosodimethylamine(NDMA). In practice, chloramines are generated by the addition of chlorine with ammonia, and plants use varying amounts of free chlorine contact time prior to ammonia addition to effectively kill pathogens and meet DBP regulations. However, iodo-DBPs and nitrosamines are generally not considered in this balancing of free chlorine contact time. The goal of our work was to determine whether an optimal free chlorine contact time could be established in which iodo-DBPs and NDMA could be minimized, while keeping regulated THMs and HAAs below their regulatory limits. The effect of free chlorine contact time was evaluated for the formation of six iodo-trihalomethanes(iodo-THMs), six iodo-acids, and NDMA during the chloramination of drinking water. Ten different free chlorine contact times were examined for two source waters with different dissolved organic carbon(DOC) and bromide/iodide. For the low DOC water at pH 7 and 8, an optimized free chlorine contact time of up to 1 h could control regulated THMs and HAAs, as well as iodo-DBPs and NDMA. For the high DOC water, a free chlorine contact time of 5 min could control iodo-DBPs and NDMA at both p Hs, but the regulated DBPs could exceed the regulations at pH 7.

关键词： Iodo-DBPs NDMA Disinfection byproducts Chloramine Drinking water Free chlorine contact time

Predicting an Athlete’s Physiological and Haematological Response to Live High-Train High Altitude Training Using a Hypoxic Sensitivity Test

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j.urnal of Science in Sport and Exercise 2022年第4期4卷 371-385页

作者： Gareth Turner Kate L.Spilsbury david j.Green Barry W.Fudge j.mie S.M.Pringle Alan j.richardson Neil S.Maxwell Environmental Extreme Laboratory University of BrightonEastbourneUK English Institute of Sport Bisham AbbeyUK Queensland Academy of Sport BrisbaneAustralia English Institute of Sport LoughboroughUK Aspire Academy DohaQatar University of Birmingham BirminghamUK

Purpose Elite endurance runners frequently utilise live high-train high(LHTH)altitude training to improve endurance per-formance at sea level(SL).Individual variability in response to the hypoxic exposure have resulted in contradictory *** the present case study,changes in total haemoglobin mass(tHbmass)and physiological capacity,in response to 4-weeks of LHTH were *** tested if a hypoxic sensitivity test(HST)could predict altitude-induced adaptations to *** Fifteen elite athletes were selected to complete 4-weeks of LHTH(~2400 m).Athletes visited the laboratory for preliminary testing(PRE),to determine lactate threshold(LT),lactate turn point(LTP),maximal oxygen uptake VO_(2max)and *** LHTH,athletes completed daily physiological measures[arterial oxygen saturation(SpO2)and body mass]and subj.ctive wellbeing *** was repeated,for those who completed the full camp,post-LHTH(POST).Additionally,athletes completed the HST prior to *** A difference(Pj.ry or *** HST did however,estimate changes in tHbmass and VO_(2max).HST prior to LHTH could allow coaches and practitioners to better inform the acclimatisation strategies and train-ing load application of endurance runners at altitude.

关键词： Altitude training Runners Endurance Haemoglobin mass Performance Hypoxic sensitivity

High-power,electronically controlled source of user-defined vortex and vector light beams based on a few-mode fiber amplifier

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Photonics Research 2021年第5期9卷 856-864页

作者： DI LIN j.EL CARPENTER YUTONG FENG YONGMIN j.NG SHAIF-UL ALAM david j.richardson Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK School of Information Technology and Electrical Engineering The University of QueenslandBrisbaneQLD 4072Australia

Optical angular momentum(OAM)-based structured light beams provide an additional degree of freedom for practical applications ranging from optical communication to laser-based material processing. Many techniques exist for generating such beams within laser sources and these primarily rely upon the use of specially designed optical components that limit laser power scaling and ready tunability of the topological charge and polarization of the output OAM beams. Here we show that some of these limitations can be overcome by employing a computer controlled reflective phase-only spatial light modulator to adaptively tailor the input(and subsequent output) beam wavefront and polarization in a few-mode fiber amplifier. In this way modal-coupling-induced beam distortion within the fiber amplifier can be mitigated and we are able to generate at will any desired supported spatial mode guided in the fiber, including conventional linearly polarized(LP) modes, scalar OAM modes, and cylindrical vector modes, at average powers >10 W and with a peak power of >11 kW. Our results pave the way to the realization of practical high-power structured laser sources with tunable chirality and polarization.

关键词： amplifier fiber power

A fine-scale assessment of the ecosystem service-disservice dichotomy in the context of urban ecosystems affected by alien plant invasions

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Forest Ecosystems 2019年第4期6卷 323-338页

作者： Luke j.Potgieter Mirij.m Gaertner Patrick j.O’Farrell david M.richardson Centre for Invasion Biology Department of Botany and ZoologyStellenbosch University

Background: Natural resources within and around urban landscapes are under increasing pressure from ongoing urbanisation, and management efforts aimed at ensuring the sustainable provision of ecosystem services(ES) are an important response. Given the limited resources available for assessing urban ES in many cities, practical approaches for integrating ES in decision-making process are ***: We apply remote sensing techniques(integrating LiDAR data with high-resolution multispectral imagery)and combined these with supplementary spatial data to develop a replicable approach for assessing the role of urban vegetation(including invasive alien plants) in providing ES and ecosystem disservices(EDS). We identify areas denoting potential management trade-offs based on the spatial distribution of ES and EDS using a local-scale case study in the city of Cape Town, South Africa. Situated within a global biodiversity hotspot, Cape Town must contend with widespread invasions of alien plants(especially trees and shrubs) along with complex socio-political challenges. This represents a useful system to examine the challenges in managing ES and EDS in the context of urban plant ***: Areas of high ES provision(for example carbon sequestration, shade and visual amenity) are characterized by the presence of large trees. However, many of these areas also result in numerous EDS due to invasions of alien trees and shrubs – particularly along rivers, in wetlands and along the urban edge where tall alien trees have established and spread into the natural vegetation(for example increased water consumption, increased fire risk and reduced soil quality). This suggests significant trade-offs regarding the management of species and the ES and EDS they ***: The approach applied here can be used to provide recommendations and to guide city planners and managers to fine-tune management interventions at local scales to maximise the provision of ES.

关键词： Biodiversity Biological invasions Ecosystem disservices Ecosystem services Remote sensing Trade-offs Tree invasions Urban plant invasions

Relationships between regulated DBPs and emerging DBPs of health concern in U.S. drinking water

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j.urnal of Environmental Sciences 2022年第7期34卷 161-172页

作者： Stuart W.Krasner Ai j.a Chih-Fen T.Lee Raha Shirkhani j.shua M.Allen Susan D.richardson Michael j.Plewa Metropolitan Water District of Southern California Water Quality LaboratoryCA 91750USA Department of Chemistry and Biochemistry University of South CarolinaSC 29208USA Department of Crop Sciences University of Illinois at Urbana-ChampaignIL 61801USA Safe Global Water Institute University of Illinois at Urbana-ChampaignIL 61801USA

A survey was conducted at eight U.S. drinking water plants, that spanned a wide range of water qualities and treatment/disinfection practices. Plants that treated heavily-wastewaterimpacted source waters had lower trihalomethane to dihaloacetonitrile ratios due to the presence of more organic nitrogen and HAN precursors. As the bromide to total organic carbon ratio increased, there was more bromine incorporation into DBPs. This has been shown in other studies for THMs and selected emerging DBPs(HANs), whereas this study examined bromine incorporation for a wider group of emerging DBPs(haloacetaldehydes, halonitromethanes). Moreover, bromine incorporation into the emerging DBPs was, in general, similar to that of the THMs. Epidemiology studies that show an association between adverse health effects and brominated THMs may be due to the formation of brominated emerging DBPs of heath concern. Plants with higher free chlorine contact times before ammonia addition to form chloramines had less iodinated DBP formation in chloraminated distribution systems, where there was more oxidation of the iodide to iodate(a sink for the iodide) by the chlorine. This has been shown in many bench-scale studies(primarily for iodinated THMs), but seldom in full-scale studies(where this study also showed the impact on total organic iodine. Collectively, the THMs, haloacetic acids, and emerging DBPs accounted for a significant portion of the TOCl, TOBr, and TOI;however, ~50% of the TOCl and TOBr is still unknown. The correlation of the sum of detected DBPs with the TOCl and TOBr suggests that they can be used as reliable surrogates.

关键词： Disinfection by-products Total organic bromine Total organic iodine Trihalomethanes Haloacetonitriles Haloacetaldehydes Iodo-trihalomethanes Iodoacetic acids