检索结果-南通市图书馆

Preparation,optical properties and energy transfer of SrLaAlO4:Dy3+,Eu3+

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第11期42卷 2058-2067页

作者： wei chen Heng Zhang Desheng Zhu School of Physic and Optoelectronic Engineering Yangtze University

A series of Dy3+/Eu3+single doped and co-doped SrLaAlO4phosphors was synthesized by the traditional high-temperature solid-state method,and their structure,morphology and optical properties were *** X-ray diffraction（XRD） shows a small amount of doping with Dy3+and Eu3+does not change the crystal structure of the matrix SrLaAlO4and the best synthesis temperature is 1450℃.The scanning electron microscopy（SEM） indicates the particle size directly ranges from 1 to 5μm roughly and the energy dispersive spectroscopy（EDS） patterns show that SrLaAlO4:Dy3+phosphor and SrLaAlO4:Dy3+,Eu3+phosphor were successfully ***4:Dy3+phosphor can be effectively excited by near-ultraviolet light,producing two strong emission lights at 483 nm（blue light） and 579 nm（yellow light）,presenting a cold white light;SrLaAlO4:Eu3+phosphor can be effectively excited by nearultraviolet light,producing red lights at 622 nm;the characteristic emission peaks of Dy3+and Eu3+can be shown simultaneously under the same excitation wavelength in SrLaAlO4:Dy3+, Eu3+*** changing the relative doping concentration ratio of Dy3+and Eu3+,the modulation of SrLaAlO4:Dy3+,Eu3+phosphor from cold white to warm white light can be *** addition,the study of the luminescent mechanism and lifetime shows that there is energy transfer between Dy3+and Eu3+in SrLaAlO4:Dy3+,Eu3+phosphor.

关键词： Energy transfer High-temperature solid-phase method Luminescence properties Rare earths SrLaAlO4: Dy3+, Eu3+ White phosphor

Complex interactions among insect viruses-insect vector-arboviruses

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2024年第3期31卷 683-693页

作者： Hui Wang Qian chen Taiyun wei State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops Vector-borne Virus Research CenterFujian Agriculture and ForestryUniversityFuzhouChina

Insects are the host or vector of diverse viruses including those that infect vertebrates,plants,and *** viruses reside inside their insect hosts and are vertically transmitted from parent to *** insect virus-host relationship is intricate,as these viruses can impact various aspects of insect biology,such as development,reproduction,sex ratios,and ***-borne viruses(arboviruses)that cause substantial global health or agricultural problems can also be vertically transmitted to insect vector *** infections with insect viruses and arboviruses are common in *** coinfections involve complex interactions,including synergism,dependence,and *** studies have shed light on the influence of insect viruses on the competence of insect vectors for *** this review,we focus on the biological effects of insect viruses on the transmission of arboviruses by *** also discuss the potential mechanisms by which insect viruses affect the ability of hosts to transmit arboviruses,as well as potential strategies for disease control through manipulation of insect *** of the interactions among insect vectors,insect viruses and arboviruses will provide new opportunities for development of innovative strategies to control arbovirus transmission.

关键词： arbovirus insect biology insect vectors insect virus interaction transmission

Winter wheat yield improvement by genetic gain across different provinces in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第2期23卷 468-483页

作者： wei chen Jingjuan Zhang Xiping Deng Key Laboratory of Disaster Monitoring and Mechanism Simulating of Shaanxi Province/School of Geography and Environment Baoji University of Arts and SciencesBaoji 721013China Centre for Crop and Food Innovation Murdoch University90 South StreetMurdochWA 6150Australia State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China

The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in *** on two sets of data,production yield from the National Bureau of Statistics of China and experimental yield from literature,this study aims to(1)illustrate the increasing patterns of production yield among different provinces from 1978 to 2018 in China,(2)explore the genetic gain in yield and yield relevant traits through the variety replacement based on experimental yield from 1937 to 2016 in China,and(3)compare the yield gap between experimental yield and production *** results show that both the production and experimental yields significantly increased along with the variety *** national annual yield increase ratio for the production yield was 1.67%from 1978 to 2018,varying from 0.96%in Sichuan Province to 2.78%in Hebei Province;such ratio for the experimental yield was 1.13%from 1937 to *** yield gap between experimental and production yields decreased from the 1970s to the *** study reveals significant increases in some yield components consequent to variety replacement,including thousand-grain weight,kernel number per spike,and grain number per square meter;however,no change is shown in spike number per square *** biomass and harvest index consistently and significantly increased,whereas the plant height decreased significantly.

关键词： genetic gain winter wheat yield yield components

维普期刊数据库

Recent progress on the functionalization of white phosphorus in China

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 308-320页

作者： Xinlei Huangfu Zhongzhen Wang Yu chen Junnian wei wei Liu Wen-Xiong Zhang Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Rare-Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular Engineering Peking University

Direct synthesis of organophosphorus compounds from white phosphorus represents a significant but challenging subject, especially in the context of ongoing efforts to comprehensively improve the phosphorus-derived chemical industry driven by sustainability and safety concerns. China is the world's largest producer of white phosphorus, creating a significant demand for the green transformation of this crucial feedstock. This review provides an overview of advancements in white phosphorus activation by Chinese research teams, focusing on the direct construction of P–C/N/O/S/M bonds from white phosphorus. Additionally, we offer some insights into prospective directions for the activation and transformation of white phosphorus in the future. This review paper aims to attract more researchers to engage in this area, stimulating follow-up exploration and fostering enduring advances.

关键词： white phosphorus organophosphorus compound activation selectivity efficiency

Cluster-Based Massive Access for Massive MIMO Systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第1期21卷 24-33页

作者： Shiyu Liang wei chen Zhongwen Sun Ao chen Bo Ai State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong UniversityBeijing 100091China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100091China Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong UniversityBeijing 100091China Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing Jiaotong UniversityBeijing 100091China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing Jiaotong UniversityBeijing 100091China School of Information Engineering Zhengzhou UniversityZhengzhou 450001China

Massive machine type communication aims to support the connection of massive devices,which is still an important scenario in *** this paper,a novel cluster-based massive access method is proposed for massive multiple input multiple output *** exploiting the angular domain characteristics,devices are separated into multiple clusters with a learned cluster-specific dictionary,which enhances the identification of active *** detected active devices whose data recovery fails,power domain nonorthogonal multiple access with successive interference cancellation is employed to recover their data via *** results show that the proposed scheme and algorithm achieve improved performance on active user detection and data recovery.

关键词： compressive sensing dictionary learning multiuser detection random access

维普期刊数据库

Tailoring of a robust asymmetric aramid nanofibers/MXene aerogel film for enhanced infrared thermal camouflage and Joule heating performances

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1990-1998页

作者： Wanbin Dang wei Guo Wenting chen Qiuyu Zhang Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

The development of infrared(IR)surveillance technology has led to a growing interest in thermal ***,the trade-off relationship between low IR-emissivity and thermal insulation hinders the advance of thermal camouflage ***,guided by multi-physics simulation,we show a design of asymmetric aramid nanofibers/MXene(ANF/MXene)aerogel film that realizes high-efficient thermal camouflage *** rationale is that the asymmetric structure contains a thermal-insulation three-dimensional(3D)network part to prevent effective heat transfer and a low IR-emissivity(~0.3)dense surface layer to suppress radiative heat *** is remarkable that the synergy mechanism in the topology structure contributes to over 40%reduction of target radiation ***,the tailored asymmetric ANF/MXene aerogel film also enables sound mechanical properties such as a young’s modulus of 44.4 MPa and a tensile strength of 1.3 MPa,superior to most aerogel *** also exhibits great Joule heating performances including low driving voltage(4 V),fast thermal response(<10 s),and long-term stability,further enabling its versatile thermal camouflage *** work offers an innovative design concept to configure multifunctional structures for next-generation thermal management applications.

关键词： asymmetric aerogel film low infrared(IR)-emissivity thermal insulation IR thermal camouflage Joule heating performance

Effects of Aging at 550℃ on α'-Martensitic Transformation of High Si-Bearing Metastable Austenitic Stainless Steel Weld Metal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1467-1479页

作者： Yakui chen Shitong wei Dong Wu Shanping Lu Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The high Si-bearing 15Cr-9Ni-Nb metastable austenitic stainless steel weld metal was prepared via gas tungsten arc welding and then processed by stabilized heat treatment(SHT)at 850℃ for 3 *** effects of 550℃ aging on the α'-martensitic transformation of the as-welded and the SHT weld metals were *** results showed that the weld metal had poor thermal stability of *** precipitation of NbC during the 850℃ SHT made the thermal stability of the local matrix decrease and led to the formation of a large amount of C-depleted α'-*** precipitation of coarse σ-phase at the δ-ferrite led to the Cr-depleted zone and the formation of Cr-depleted α'-martensite at the early stage of 550℃ *** homogenized diffusion of C and Cr in the matrix during 550℃ aging led to the restoration of austenitic thermal stability and the decrease of α'-martensite *** C-depleted α'-martensite content in the SHT weld metal decreased rapidly at the early stage of aging due to the fast diffusion rate of the C atom in the matrix,while the Cr-depleted α'-martensite decreased at the later stage of aging due to the decreased diffusion rate of the Cr.

关键词： Metastable austenitic stainless steel weld metal α'-martensitic transformation δ-ferrite σ-phase

Automated Identification of Ordered Phases for Simulation Studies of Block Copolymers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 683-692,I0011页

作者： Yu-chen Zhang wei-Ling Huang Yi-Xin Liu State Key Laboratory of Molecule Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China

In unit cell simulations,identification of ordered phases in block copolymers(BCPs)is a tedious and time-consuming task,impeding the advancement of more streamlined and potentially automated research *** this study,we propose a scattering-based automated identification strategy(SAIS)for characterization and identification of ordered phases of BCPs based on their computed scattering *** approach leverages the scattering theory of perfect crystals to efficiently compute the scattering patterns of periodic morphologies in a unit *** the first stage of the SAIS,phases are identified by comparing reflection conditions at a sequence of Miller *** confirm or refine the identification results of the first stage,the second stage of the SAIS introduces a tailored residual between the test phase and each of the known candidate ***,our strategy incorporates a variance-like criterion to distinguish background species,enabling its extension to multi-species BCP *** has been demonstrated that our strategy achieves exceptional accuracy and robustness while requiring minimal computational ***,the approach allows for real-time expansion and improvement to the candidate phase library,facilitating the development of automated research workflows for designing specific ordered structures and discovering new ordered phases in BCPs.

关键词： Block copolymer Phase identification Scattering function

维普期刊数据库

Optimizing mechanical properties of HIPS fabricated with low-cost desktop 3D printers:investigating the impact of process parameters

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 379-395页

作者： Jin-Ting Xu Guang-wei Zhang Man-Man chen School of Automotive Engineering Dalian University of TechnologyDalian116024People’s Republic of China

Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread ***,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D *** this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were *** experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed *** prediction models of the process parameters were regressed to produce the optimal combination of process *** experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile *** an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer *** addition,they all increased with an increase of infill *** was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were *** results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.

关键词： Desktop three-dimensional(3D)printers Fused deposition modeling(FDM) High-impact polystyrene(HIPS) Process parameters