检索结果-南通市图书馆

Converting TREx-RGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 258-274页

作者： Jun Liang d.M.Gillies E.Spanswick E.f.donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and *** the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TREx-RGB camera is usually dominated by the 557.7 nm *** this rationale,the TREx mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm *** this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB *** illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TREx spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-Earth-orbit satellites,with the aid of an auroral transport *** demonstrate the procedures and provide initial results for the TREx-RGB ASIs at the Rabbit Lake and Lucky Lake *** RGB response is found to be *** conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TREx-RGB data *** methodology established in this study will also be applicable to the upcoming SMILE ASI mission,which will adopt a similar RGB camera system in its deployment.

关键词： TREx RGB green-line aurora auroral transport model

Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2024年第9期45卷 28-35页

作者： Leonarde N.Rodrigues Wesley f.Inoch Marcos L.f.Gomes Odilon d.d.Couto Jr. Bráulio S.Archanjo Sukarno O.ferreira Physics department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2d character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0d) 0d nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

发展中国家筛查结核病接触者合适吗?1996-1998年尼泊尔东部地区的经验

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

结核病健康教育 2001年第1期 45-49页

作者： d.f.wares M.Akhtar S.Singh H.LuiteI 邹级谦张立兴 The Britain-Nepal Medical Trust Biratnagar Nepl Eastern Mediterranean Region Office World Health Organisation Alexandria Egypt 卫生部结核病控制中心北京结核病控制研究所

背景:此项结核病研究是由一家非政府组织在尼泊尔东部8个丘陵及山区地区实施的。目的:评价筛查接触者对病例发现的作用。设计:对1996—1998年诊断并登记的"首登病例"(index cases),即涂片阳性、涂片阴性和肺外结核病例的接触者进行回顾... 详细信息

背景:此项结核病研究是由一家非政府组织在尼泊尔东部8个丘陵及山区地区实施的。目的:评价筛查接触者对病例发现的作用。设计:对1996—1998年诊断并登记的"首登病例"(index cases),即涂片阳性、涂片阴性和肺外结核病例的接触者进行回顾性队列研究。首登病例的家庭成员为接触者,接触者经疫检筛查,2份痰涂片阳性者确定为涂阳肺结核病例。结果:大约从50%(668)的登记病人中确定接触者;在确定的接触者中75%(2298)送检1个或以上的痰标本。从接触者中共筛查出14例(0.61%)涂阳肺结核病例,除1例外,13例涂阳肺结核病人都是从涂阳肺结核首登病例的接触者中检出的。从涂阳菌量≥2+的首登病例接触者中检出的涂阳肺结核病人是涂阳菌量1+者的7.2倍(P=0.04)。讨论:在这样的背景下,从涂阴肺结核或肺外结核病人的家庭接触者中用痰检筛查是不合适的。为了评价筛查没有症状的涂阳肺结核病例接触者的实用性以及通过筛查痰菌量大(>24)病例的接触者是否可以改善费用效益,有必要进一步的评估。

关键词：结核病接触者筛查发展中国家尼泊尔

The magnetosheath at high spectral resolution

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.d.Küntz d.Koutroumpa W.R.dunn A.foster f.S.Porter d.G.Sibeck B.Walsh The Henry A.Rowland department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/Birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： f.Momo TEMGOUA L.Akana NGUIMdO dNJOMO Environmental Energy Technologies Laboratory(EETL) Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon department of Electrical and Electronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of Legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined delta function and Modified Eddington, and second-order approximation methods with reference to the discrete Ordinate(disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation(f-TSA) developed in a previous work. Notably,New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the disort method(R ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the Legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method Legendre polynomial optical thickness moments of specific intensity conversion function transmittance reflectance

design of a Novel Exoskeleton with Passive Magnetic Spring Self-locking and Spine Lateral Balancing

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第1期21卷 236-255页

作者： Jhon f.Rodríguez-León Betsy d.M.Chaparro-Rico daniele Cafolla francesco Lago Eduardo Castillo-Castañeda Giuseppe Carbone Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada Unidad Querétaro MecatronicaInstituto Politécnico NacionalCerro Blanco 14176090 Colinas del CimatarioQuerétaroMexico department of Mechanical Energy and Management EngineeringUniversity of CalabriaVia P.Bucci Cubo 46 C87036 RendeItaly faculty of Science and Engineering Department of Computer ScienceSwansea UniversitySwanseaUK CESTER University of Cluj-NapocaCluj-NapocaRomania

This paper proposes a new upper-limb exoskeleton to reduce worker physical *** proposed design is based on a novel PRRRP(P-Prismatic;R-Revolute)kinematic chain with 5 passive degrees of freedom(dof).Utilizing a magnetic spring,the proposed mechanism includes a specially designed locking mechanism that maintains any desired task *** proposed exoskeleton incorporates a balancing mechanism to alleviate discomfort and spinal torsional effects also helping in limb weight *** paper reports specific models and simulations to demonstrate the feasibility and effectiveness of the proposed *** experimental characterization is performed to validate the performance of the mechanism in terms of forces and physical strain during a specific application consisting of ceiling-surface drilling *** obtained results preliminarily validate the engineering feasibility and effectiveness of the proposed exoskeleton in the intended operation task thereby requiring the user to exert significantly less force than when not wearing it.

关键词： Assistive mechanism Exoskeleton Locking mechanism Bionic robot

Bolstering integrity in environmental data science and machine learning requires understanding socioecological inequity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

frontiers of Environmental Science & Engineering 2024年第5期18卷 171-179页

作者： Joe f.Bozeman III School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA30332USA School of Public Policy Georgia Institute of TechnologyAtlantaGA30332USA

Socioecological inequity in environmental data science—such as inequities deriving from data-driven approaches and machine learning(ML)—are current issues subject to debate and *** is growing consensus around embedding equity throughout all research and design domains—from inception to administration,while also addressing procedural,distributive,and recognitional ***,practically doing so may seem onerous or daunting to *** current perspective helps to alleviate these types of concerns by providing substantiation for the connection between environmental data science and socioecological inequity,using the Systemic Equity framework,and provides the foundation for a paradigmatic shift toward normalizing the use of equity-centered approaches in environmental data science and ML *** the integrity of environmental data science and ML is just beginning from an equity-centered tool development and rigorous application *** this end,this perspective also provides relevant future directions and challenges by overviewing some meaningful tools and strategies—such as applying the Wells-du Bois Protocol,employing fairness metrics,and systematically addressing irreproducibility;emerging needs and proposals—such as addressing data-proxy bias and supporting convergence research;and establishes a ten-step path ***,the work that environmental scientists and engineers do ultimately affect the well-being of us all.

关键词： Equity Bias Machine Learning data Science Justice Systemic Equity

Nickel sulfate solution fluoride separation with hydrous zirconium oxide

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tungsten 2024年第2期6卷 367-381页

作者： Elbert M.Nigri Ummul K.Sultana André L.A.Santos James W.Vaughan Sonia d.f.Rocha department of Mining Engineering Federal University of Minas GeraisBelo Horizonte 31270-901Brazil School of Chemical Engineering University of QueenslandSt Lucia 4072Australia

fluoride is an impurity in nickel sulfate production,which is required for electric vehicle *** zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate *** fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr *** availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous *** removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate *** removal was dominated by an ion exchange mechanism and resulting Zr–f bonds were observed using fourier-transform infrared *** presence of nickel sulfate decreased loading capacity compared to a salt-free *** maintained adsorption capacity through five cycles of loading and regeneration.

关键词： Hydrous zirconium oxide Nickel sulfate fluoride Adsorption Anion exchange

在线全文

学校读者我要写书评

暂无评论

印度结核病患者中的HIV感染率估算

国际结核病与肺部疾病杂志 2010年第1期5卷 39-41页

作者： P.K.dewan d.Gupta B.G.Williams R.Thakur d.Bachani A.Khera d.f.wares S.Sahu d.C.S.Reddy N.Raizada L.S.Chauhan 王冬梅王雪静 Office of the World Health Organization Representative to India New Delhi Central Tuberculosis division Directorate General of Health ServicesMinistry of Health and Family WelfareGovernment of IndiaNew DelhiIndia Consultant GenevaSwitzerland National AIdS Control Organization Ministry of Health and Family WelfareGovernment of IndiaNew Delhi foundation for Innovative New diagnostics New DelhiIndia

使用全球的数据已经对印度结核病(TB)患者的人类免疫缺陷病毒(HIV)感染状况进行了间接估算。为了使用当地数据对HIV感染状况进行更加准确的估算,我们将县/区级产前门诊的HIV监测数据与结核病诊断中心的HIV监测数据联系起来,并将这一关... 详细信息

使用全球的数据已经对印度结核病(TB)患者的人类免疫缺陷病毒(HIV)感染状况进行了间接估算。为了使用当地数据对HIV感染状况进行更加准确的估算,我们将县/区级产前门诊的HIV监测数据与结核病诊断中心的HIV监测数据联系起来,并将这一关联性应用到省级对孕妇人群的HIV感染状况估算中。我们估计,2007年196万新发结核病患者的HIV感染率为4.85%(95%可信区间为4.12～5.73)或HIV感染人数为95 240(95%可信区间为80 730～112 478)例。从使用这些当地数据所进行的估算中,国家结核病防治规划能够更好的制定TB/HIV双重感染防治联合行动,并监控在这一大规模人群中发现HIV感染者的结果。

关键词： HIV 结核监测印度