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Time-Frequency Bandwidth Product Estimation of Sinusoidal Non-Linear Chirp Keying Scheme

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China Communications 2017年第8期14卷 184-194页

作者： Zhiguo Sun Xiaoyan ning Danyang Tian College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Shijiazhuang 050000China University of Califomia RiversideCalifornia 92521USA

Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some parameter estimation issues over conventional modulation schemes. In this paper, a novel transform termed as Discrete Sinusoidal Frequency Modulation transform(DSFMT) is proposed. Then, the DSFMT of SNCK signal is deduced and classified into three types, based on which, the time-bandwidth product is estimated by the proposed algorithm. Simulation results show that the noise has a signifi cant impact on the localization of the peak value and the time-bandwidth product can be estimated by using local ratio values when.

关键词：非线性调频估计问题正弦调频键控频带宽时间带宽积乘积调制方式

Responses of nutrient biogeochemistry and nitrogen cycle to seasonal upwelling in coastal waters of the eastern Hainan Island

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Acta Oceanologica Sinica 2022年第6期41卷 99-113页

作者： Nan Zhou Sumei Liu Guodong Song Yunyan Zhang Lingyan Wang Xiaoyan ning Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology of Ministry of EducationOcean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

The coastal upwelling has profound influence on the surrounding ecosystem by supplying the nutrient-replete water to the euphotic zone.Nutrient biogeochemistry was investigated in coastal waters of the eastern Hainan Island in summer 2015 and autumn 2016.From perspectives of nutrient dynamics and physical transport,the nutrient fluxes entered the upper 50 m water depth(between the mixed layer and the euphotic zone)arisen from the upwelling were estimated to be 2.5-5.4 mmol/(m^(2)·d),0.15-0.28 mmol/(m^(2)·d),and 2.2-7.2 mmol/(m^(2)·d)for dissolved inorganic nitrogen(DIN),phosphate(DIP),and dissolved silicate(DSi),respectively,which were around 6-to 12-fold those in the background area.The upwelled nutrients supported an additional plankton growth of(14.70±8.95)mg/m^(2)for chlorophyll a(Chl a).The distributions of nitrateδ^(15)N andδ^(18)O above the 300 m water depth(top of the North Pacific Intermediate Water)were different among the upwelling area,background area in summer,and the stations in autumn,and the difference of environmental and biogeochemical conditions between seasons should be the reason.The higher DIN/DIP concentration ratio,nitrate concentration anomaly,and lower nitrate isotope anomaly(Δ(15,18))in the upper ocean in summer than in autumn indicated the stronger nitrogen fixation and atmospheric deposition,and the following fixed nitrogen regeneration in summer.The higher values of Chl a and nitrateδ^(15)N andδ^(18)O within the euphotic zone in autumn than the background area in summer suggested the stronger nitrate assimilation in autumn.The differences in relatively strength of the assimilation,nitrogen fixation and atmospheric deposition,and the following remineralization and nitrification between the two seasons made the higherδ^(18)O:δ^(15)N and larger difference of enzymatic isotope fractionation factors^(15)εand^(18)εfor nitrate assimilation in summer than in autumn above the North Pacific Tropical Water.

关键词： nutrients upwelling nitrateδ^(15)N andδ^(18)O nitrogen cycle South China Sea

Solar Flux Measuring and Optical Efficiency Forecasting of the Linear Fresnel Reflector Concentrator after Dust Accumulation

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Journal of Thermal Science 2022年第3期31卷 663-677页

作者： ZHAO xiaoyan YAN Suying ZHANG Na ZHAO ning GAO Hongwei College of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot010051China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

The linear Fresnel reflector concentrator(LFRC)is widely used in the field of solar energy utilization due to its simple structure,low cost,and excellent wind resistance.Nevertheless,the LFRC operates outdoors all year round,and the dust accumulation on the mirror will reduce the optical efficiency of the system,so it needs to be perfected and improved.In this paper,a focal plane energy flux experimental device was designed to test the energy flux of the system under different dust accumulation times.The results indicate that,the dust density on the mirror increased and the energy flux on the focal plane decreased with increase of dust accumulation time.After undergoing dust accumulation for 35 days,the dust density on the mirror reached 4.33 g/m^(2)and the average energy flux on the focal plane decreased to 1.78 kW/m^(2).Additionally,the variation of reflectivity caused by dust accumulation on mirror was taken as the quantitative index,and a prediction model for the impact of dust on the optical efficiency of the system was proposed.The results will provide guidance for improving the optical efficiency of the LFRC.

关键词： dust accumulation energy flux linear Fresnel reflector concentrator optical efficiency forecast

Fabrication and characterization of epoxylated zwitterionic copolymergrafted silica nanoparticle as a new support for lipase immobilization

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1129-1135页

作者： ning Chen Chunyu Zhang xiaoyan Dong Yan Sun Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300354China

Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(glycidyl methecrylate)(pGMA)grafted SNP,while the latter showed significantly increased activity.Inspired by the research,we have herein proposed to synthesize copolymers of zwitterionic sulfobetaine methacrylate(SBMA)and GMA for CRL immobilization.The copolymers were grafted onto SNP surface at three GMA/SBMA(G/S)molar ratios(G100/S0,G50/S50,G10/S90),followed by the covalent coupling of CRL to the surface copolymers.The immobilized CRLs on the corresponding supports were denoted as p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL.The enzyme loading increased with the increase of GMA content in the copolymer,while the activity varied with the grafted copolymer composition.Kinetic study proved the improvement of enzyme-substrate affinity after immobilization.In comparison to p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL presented remarkably enhanced thermal stability and pH tolerance,and p(G10-S90)-CRL showed the highest stability.These results suggest that the copolymer design is promising for development as a versatile platform for enzyme immobilization.

关键词： Lipase Immobilization Zwitterionic copolymer Interfacial activation Stabilization

Analysis of the Light Concentration Loss of a Fresnel CPV/T System after Dust Accumulation

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Journal of Thermal Science 2022年第6期31卷 1868-1880页

作者： ZHAO ning YAN Suying MA Xiaodong WU Ze MING Tingzhen ZHAO xiaoyan ZHANG Na College of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot O10051China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China

Dust accumulation is one of the reasons for the performance degradation of concentrating photovoltaic and thermal(CPV/T) systems due to the deposition of dust particles with different compositions, shapes, sizes, and masses. In this work, an optical model was developed to investigate the influence of the particle size, diameter, shape, and deposition density on the light concentration efficiency, using the Monte Carlo raytracing(MCRT) method in the Tracepro software. The triangular particles had a larger influence on the light ray deflection and energy flux degradation than the circular and square particles. An average increase in the dust density of 1 g/m^(2) decreased the light concentration efficiency of particles with sizes smaller than 50 μm and 60 μm by 3.31% and 3.26%, respectively. Furthermore, the effect of the incidence angle on the light concentration efficiency was considered at an angle less than 2°.

关键词： dust accumulation Fresnel CPV/T system light concentration efficiency Monte Carlo raytracing

Using pipette tips to readily generate spheroids comprising single or multiple cell types

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第10期24卷 875-885页

作者： Rong PAN xiaoyan YANG Shiming WU Yuanyuan XIE Feng CHEN Ke ning Wei SUN Ling YU Key Laboratory of Luminescence Analysis and Molecular Sensing Ministry of EducationInstitute for Clean Energy and Advanced MaterialsSchool of Materials and EnergySouthwest UniversityChongqing 400715China College of Chemistry and Chemical Engineering Hainan Normal UniversityHaikou 571158China

Three-dimensional(3D)cell culture methods have been validated that can replicate the tumor environment in vivo to a large extent,providing an effective tool for studying tumors.In this study,we demonstrated the use of standard laboratory pipette tips as micro vessels for generating 3D cell spheroids.No microfabrication or wet-chemistry surface modifications were involved in the procedure.Spheroids consisting of single or multiple cell types were generated within 24 h just by pipetting and incubating a cell suspension in pipette tips.Scanning electron microscope and optical microscope proved that the cells grew together tightly,and suggested that while gravity force might have initiated the sedimentation of cells at the bottom of the tip,the active aggregation of cells to form tight cell-cell interactions drove the formation of spheroids.Using common laboratory micropipettes and pipette tips,the rate of spheroid generation and the generation reproducibility was characterized from five boxes each with 80 tips.The ease of transferring reagents allowed modeling of the growth of microvascular endothelial cells in tumor spheroids.Moreover,the pairing and fusion of tumor spheroids could be manipulated in the pipette tips,suggesting the potential for building and assembling heterogeneous micro-tumor tissues in vitro to mimic solid tumors in vivo.This study demonstrated that spheroids can be readily and cost-effectively generated in standard biological laboratories in a timely manner using pipette tips.

关键词： Pipette tip 3D cell culture Tumor spheroids Co-culture In-situ observation

Silicon-substituted rhodamines for stimulated emission depletion fluorescence nanoscopy

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Chinese Chemical Letters 2022年第1期33卷 133-140页

作者： ning Wang Yumeng Hao Xiaowei Feng Haidan Zhu Dazhi Zhang Ting Wang xiaoyan Cui Department of Chemistry School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200241China Department of Organic Chemistry College of PharmacyNaval Medical University(Second Military Medical University)Shanghai 200433China

As an essential part in the toolbox of super-resolution microscopy,stimulated emission depletion(STED)nanoscopy has been widely explored in revealing the substructure and bioactivities in fluorescence imaging.Among the applied STED fluorophores,silicon-substituted rhodamines(SiRs)belong to one of the most extensively employed fluorophores.The carboxy-SiR was favored in STED bioimaging with many advantages,including reliable photostability,cell permeability,tunable fluorogenicity,feasible structural decoration and so on.We reviewed the research of carboxy-SiR in the STED nanoscopy and hopefully this can inspire more efforts in the design and application of STED fluorophores.

关键词： Silicon Xanthene Super-resolution Stimulated emission depletion

Boosting the catalytic performance of Cu-SAPO-34in NO_(x) removal via hydrothermal treatment

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Journal of Environmental Sciences 2024年第1期135卷 640-655页

作者： xiaoyan Tian Huimin Wang Siyuan Xu Lianyun Gao Jinyan Cao Jianjun Chen Qiulin Zhang Ping ning Jiming Hao Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries Kunming University of Science and TechnologyKunming 650500China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution ControlTsinghua UniversityBeijing 100084China

Phosphate ions promoted Cu-SAPO-34(P-Cu-SAPO-34)were prepared using bulk CuO particles as Cu^(2+)precursor by a solid-state ion exchange technique for the selective catalytic reduction of NO_(x) with NH_3(NH_3-SCR).The effects of high temperature(H-T)hydrothermal aging on the NO_(x) removal(de-NO_(x))performance of Cu-SAPO-34 with and without phosphate ions were systematically investigated at atomic level.The results displayed that both Cu-SAPO-34 and P-Cu-SAPO-34 presented relatively poor NO_(x) removal activity with a low conversion(<30%)at 250-500℃.However,after H-T hydrothermal treatment(800℃ for 10 hr at 10%H_2O),these two samples showed significantly satisfied NO_(x) elimination performance with a quite high conversion(70%-90%)at 250-500℃.Additionally,phosphate ions decoration can further enhance the catalytic performance of Cu-SAPO-34 after hydrothermal treatment(Cu-SAPO-34H).The textural properties,morphologies,structural feature,acidity,redox characteristic,and surface-active species of the fresh and hydrothermally aged samples were analyzed using various characterization methods.The systematical characterization results revealed that increases of 28%of the isolated Cu^(2+)active species(Cu^(2+)-2Z,Cu(OH)^(+)-Z)mainly from bulk CuO and 50%of the Bronsted acid sites,the high dispersion of isolated Cu^(2+)active component as well as the Bronsted acid sites were mainly responsible for the accepted catalytic activity of these two hydrothermally aged samples,especially for P-Cu-SAPO-34H.

关键词： NH_(3)-SCR Cu-SAPO-34 Hydrothermal induced Phosphate ions

Ultralong organic room-temperature phosphorescence of electrondonating and commercially available host and guest molecules through efficient Förster resonance energy transfer

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Science China Chemistry 2021年第5期64卷 739-744页

作者： Yeling ning Junfang Yang Han Si Haozhong Wu xiaoyan Zheng Anjun Qin Ben Zhong Tang State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSCUT-HKUST Joint Research InstituteAIE InstituteCenter for Aggregation-Induced EmissionSouth China University of Technology(SCUT)Guangzhou 510640China Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster Science of Ministry of EducationBeijing Institute of TechnologyBeijing 100081China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionInstitute for Advanced Studyand Department of Chemical and Biological EngineeringThe Hong Kong University of Science&Technology(HKUST)Clear Water BayKowloonHong KongChina

Ultralong organic room-temperature phosphorescence(RTP)materials have attracted tremendous attention recently due to their diverse applications.Several ultralong organic RTP materials mimicking the host-guest architecture of inorganic systems have been exploited successfully.However,complicated synthesis and high expenditure are still inevitable in these studies.Herein,we develop a series of novel host-guest organic phosphorescence systems,in which all luminophores are electron-rich,commercially available and halogen-atom-free.The maximum phosphorescence efficiency and the longest lifetime could reach 23.6%and 362 ms,respectively.Experimental results and theoretical calculation indicate that the host molecules not only play a vital role in providing a rigid environment to suppress non-radiative decay of the guest,but also show a synergistic effect to the guest through Förster resonance energy transfer(FRET).The commercial availability,facile preparation and unique properties also make these new host-guest materials an excellent candidate for the anti-counterfeiting application.This work will inspire researchers to develop new RTP systems with different wavelengths from commercially available luminophores.

关键词： room-temperature phosphorescence host-guest system Förster resonance energy transfer commercial luminophore anti-counterfeiting