检索结果-南通市图书馆

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

引用

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 f.rmalized by the radiative transf.r equation(RTE), whose resolution calls f.r two-stream approximations among other methods. This paper proposes a new two-stream approximation of.the RTE with the development of.the phase f.nction 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 f.nction, allows in the conditions of.a plane parallel atmosphere a new mathematical f.rmulation of.γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta f.nction and Modif.ed Eddington, and second-order approximation methods with ref.rence to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion f.nction of.the proposed New Method using the f.ndamental def.nition 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 f.r wide domains of.the zenith angle μ 0, but tends to deviate f.om the Disort method with the zenith angle, especially f.r high values of.optical thickness. In spite of.this divergence in ref.ectance f.r high values of.optical thickness, very strong correlation with the Disort method(R ≈ 1) was obtained f.r most cases of.optical thickness in this study. An analysis of.the Legendre polynomial series f.r simple f.nctions shows that the high precision is due to the f.ct that the approximated f.nctions ameliorate the accuracy when the order of.approximation increases, although it has been proven that there is a limit order depending on the f.nction f.om which the precision is lost. This observation indicates that increasing the order of.app

关键词： Radiative Transf.r Equation two-stream method Legendre polynomial optical thickness moments of.specif.c intensity conversion f.nction transmittance ref.ectance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Semi-automated detection of.rangeland runof. and erosion control berms using high-resolution topography data

引用

International Soil and Water Conservation Research 2024年第1期12卷 217-226页

作者： li li Changjiang River Scientif.c Research Institute of.Changjiang Water Resources Commission Wuhan430010China Research Center on Mountain Torrent&Geologic Disaster Prevention Ministry of Water ResourcesWuhan430010China University of.Arizona School of Natural Resources and the EnvironmentTucsonAZ85719USA

An inventory of.topographic modif.cations is essential to addressing their impacts on hydrological and morphological processes in human-altered ***,such inventories are generally *** study presents two workf.ows f.r semi-automatic detection of.linear earthen runof. and erosion control berms in rangelands using high-resolution topographic *** workf.ows consist of.initial object identif.cation by applying either morphological grayscale reconstruction(MGR)or the Geomorphon(GEO)method,f.llowed by identif.cation ref.nements through f.lters based on objects’horizontal and vertical *** sites were selected within the Altar Valley,Arizona,in the southwestern United *** site was used f.r developing workf.ows and optimizing f.lter thresholds,and the other two sites were used to validate *** results showed that:1)The MGR-based workf.ow methodology could produce f.nal precision and detection rates of.up to 92%and 75%,respectively,and take less than 5 s f.r a 10.1 km^(2) site;2)The workf.ow based on the MGR method yielded greater identif.cation accuracy than did the GEO workf.ow;3)Object length,orientation,and eccentricity were important characteristics f.r identif.ing earthen berms,and are sensitive to general channel f.ow direction and berm shape;4)Manual interrogation of.topographic data and imagery can signif.cantly improve identif.cation precision *** proposed workf.ows will be usef.l f.r developing inventories of.runof. and erosion control structures in support of.sustainable rangeland management.

关键词： Earthen berm Rangeland Grayscale morphological reconstruction Geomorphon liDAR

来源：

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

A review:the mechanism of.plant-derived polysaccharides on osteoblasts and osteoclasts

引用

未来食品学报(英文) 2024年第3期4卷 183-192页

作者： Mengjie Ren Adel f.Ahmed Meng li Menghan li Zhiruo Yan Jinmei Wang National R&D Center f.r Edible f.ngus Processing Technology Henan UniversityKaifeng 475004China Joint International Research Laboratory of.0}od&Medicine Resource f.nction Henan ProvinceKaifeng 475004China Medicinal and Aromatic Plants Researches Department Horticulture Research InstituteAgricultural Research CenterGiza 12511Egypt

Bone loss and deterioration of.bone microarchitecture would increase the bone f.agility and f.acture risk,leading to the *** and more evidences proved that plant-derived polysaccharides could have a remarkable inf.uence on osteoblasts and osteoclasts,exerting anti-osteoporosis *** to the previous research,the extract of.Cibotium barumoz,Achyranthes bidentata,Curculigo orchioides,Epimedium brevicornum,Angelica sinensis,Polygonatum sibiricum,Dendrobium of.icinale,Morinda of.icinalis,Nelumbo mucif.ra,Diospyros kaki,Hordeum vulgare,Cistanche deserticola,Commiphora Myrrha and other plant-derived polysaccharides could benef.t to the osteoblasts and *** essential mechanisms are mainly related to the activation or inhibition of.many f.ctors,including runt-related transcription f.ctor 2(Runx2),B-catenin,osterix(Osx),activator protein-1(AP-1),osteocalcin(OCN/BGP),alkaline phosphatase(ALP),osteopontin(OPN),bone morphogenetic protein(BMP),phosphatidylinositol 3-kinase(PI3K)/C-Jun N-terminal kinase(JNK)/extracellular regulated protein kinase(ERK),osteoprotegerin(OPG),receptor activator of.nuclear f.ctor-kB(RANK),monocyte/macrophage colony-stimulating f.ctor(M-CSf.,tumor necrosis f.ctor receptor-associated f.ctor 6(TRAf.6),receptor activator of.nuclear f.ctor(Nf.-KB ligand(RANKL),nuclear f.ctor of.activated T cells 1(Nf.Tc1),c-f.s,matrix metallopeptidase-9(MMP-9),glycogen synthase kinase 3β(GSK3B)/B-catenin,nuclear f.ctor E2-related f.ctor 2(Nf.),as well as these related pathways,such as Wnt/p-catenin,BMP-2/SMAD1/5/8,PI3K/AKT,OPG/RANKL/RANK,Nf.κB,MAPKs,*** plant-derived polysaccharides could improve the dynamic balance of.bone f.rmation and resorption through promoting the dif.erentiation and maturation of.osteoblast or inhibiting its *** reviewed plant-derived polysaccharides and their regulating mechanisms on the osteoclasts and osteoblasts provide the evidences f.r the development of.osteoporosis therapeutics.

关键词： Osteoporosis Plant-derived polysaccharides Osteogenesis promotion Osteoclasts inhibition

来源：

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

Ef.ects of.mid-passage gap with a variable surf.ce angle on a turbine vane endwall’s aerothermal and f.lm cooling perf.rmances

引用

Chinese Journal of.Aeronautics 2024年第6期37卷 20-37页

作者： Zhiyu li Kaiyuan ZHANG Zhigang li Jun li Institute of.Turbomachinery Xi’an Jiaotong UniversityXi’an 710049China

The mid-passage gap is an inevitable structure in a vane passage due to turbine vanes being manuf.ctured *** coolant f.om this gap is able to prevent hot mainstream ingression and provide cooling protection f.r the endwall.A novel idea of.enlarging the endwall’s coverage area and reducing the endwall’s thermal load by applying the mid-passage gap with variable surf.ce angles is carried out in this *** endwall’s aerothermal and f.lm cooling perf.rmances under f.ur mid-passage gap modes at three typical mass f.ow ratio conditions are numerically *** indicate that under the traditional mid-passage mode,the coolant f.ows into the mainstream with a perpendicular incidence angle and can’t stick to the ***,cooling f.ilure occurs,and the endwall’s thermal load is badly *** f.lm cooling level at the suction-side endwall is improved when applying the mid-passage gap of.a 45surf.ce angle due to the secondary vortex being *** addition,when applying the mid-passage gap of.a 135surf.ce angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged *** best f.lm cooling perf.rmance is achieved when the upstream surf.ce angle is 135and the downstream surf.ce angle is 45due to the adiabatic f.lm cooling ef.ectiveness being increased at both the pressure-and suction-side *** the mass f.ow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic f.lm cooling ef.ectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关键词： f.lm cooling Heat transf.r Surf.ce angle Mid-passagegap Turbinevane endwall

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Theoretical Analysis of.Cooperative Driving at Idealized Unsignalized Intersections

引用

Tsinghua Science and Technology 2024年第1期29卷 257-270页

作者： Shen li Jiawei Zhang Zhenwu Chen li li Department of.Civil Engineering Tsinghua UniversityBeijing 100084China Department of.Automation Tsinghua UniversityBeijing 100084China Shenzhen Urban Transport Planning Center Co. Ltd.Shenzhen 518000China

Cooperative driving is widely viewed as a promising method to better utilize limited road resources and alleviate traf.ic *** recent years,several cooperative driving approaches f.r idealized traf.ic scenarios(i.e.,unif.rm vehicle arrivals,lengths,and speeds)have been ***,theoretical analyses and comparisons of.these approaches are *** this study,we propose a unif.ed group-by-group zipper-style movement model to describe dif.erent approaches synthetically and evaluate their *** derive the maximum throughput f.r cooperative driving plans of.idealized unsignalized intersections and discuss how to minimize the delay of.*** obtained conclusions shed light on f.ture cooperative driving studies.

关键词： cooperative driving connected and automated vehicles unsignalized intersection

来源：

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

Perturbed low-thrust geostationary orbit transf.r guidance via polynomial costate estimation

引用

Chinese Journal of.Aeronautics 2024年第3期37卷 181-193页

作者： Zhao li Hengnian li f.nghua JIANG Junf.ng li State Key Laboratory of.Astronautic Dynamics Xi’an Satellite Control CenterXi’an 710043China School of.Aerospace Engineering Tsinghua UniversityBeijing 100084China

This paper proposes an optimal,robust,and ef.icient guidance scheme f.r the perturbed minimum-time low-thrust transf.r toward the geostationary *** Earth’s oblateness perturbation and shadow are taken into *** is dif.icult f.r a Lyapunov-based or trajectory-tracking guidance method to possess multiple characteristics at the same time,including high guidance optimality,robustness,and onboard computational *** this work,a concise relationship between the minimum-time transf.r problem with orbital averaging and its optimal solution is identif.ed,which reveals that the f.ve averaged initial costates that dominate the optimal thrust direction can be approximately determined by only f.ur initial modif.ed equinoctial orbit elements af.er a coordinate *** on this relationship,the optimal averaged trajectories constituting the training dataset are randomly generated around a nominal averaged *** polynomial regression models are trained on the training dataset and are regarded as the costate *** the transf.r,the spacecraf. can obtain the real-time approximate optimal thrust direction by combining the costate estimations provided by the estimators with the current state at any ***,all these computations onboard are *** simulation results show that the proposed guidance scheme possesses extremely high guidance optimality,robustness,and onboard computational ef.iciency.

关键词： Low thrust Orbital transf.r Trajectory optimization Guidance Indirect method Orbital averaging Machine learning Geostationary satellites

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ultrathin organic solvent nanof.ltration membrane with polydopamine-HKUST-1 interlayer f.r organic solvent separation

引用

Journal of.Environmental Sciences 2024年第7期141卷 182-193页

作者： Haike li Xindong li Guozai Ouyang lijinhong Huang Lang li Wenhao li Wanf. Huang Duokun li Ganzhou Key Laboratory of.Basin Pollution Simulation and Control Jiangxi University of Science and TechnologyGanzhou 341000China Innovation Center f.r Water Quality Security Technology at Ganjiang River Basin Jiangxi University of Science and TechnologyGanzhou 341000China School of.Architecture and Design Jiangxi University of Science and TechnologyGanzhou 341000China WA School of.Mines:Minerals Energy and Chemical EngineeringCurtin UniversityWA 6845Australia School of.Materials Science and Engineering Tiangong UniversityTianjin 300387China

Polydopamine(PDA)and metal-organic skeleton HKUST-1 were co-deposited on the base membrane of.hexamethylenediamine(HDA)-crosslinked polyetherimide(PEI)ultraf.ltration membrane as the interlayer,and high-throughput organic solvent nanof.ltration membrane(OSN)was prepared by interf.cial polymerization and solvent activation *** polyamide(PA)layer surf.ce roughness f.om 28.4 nm in PA/PEI to 78.3 nm in PA/PDA-HKUST-10.6/PEI membrane,reduced the thickness of.the separation layer f.om 79 to 14 nm,and signif.cantly improved the hydrophilic,thermal and mechanical *** f.ux of.the PA/PDA-HKUST-10.6/PEI membrane in a 0.1 g/L Congo Red(CR)ethanol solution at 0.6 MPa test pressure reached 21.8 L/(m^(2)·hr)and the rejection of.CR was 92.8%.Solvent adsorption test,N,N-dimethylf.rmamide(DMf.immersion experiment,and long-term operation test in ethanol showed that the membranes had high solvent *** solvent f.ux test demonstrated that,under the test pressure of.0.6 MPa,the f.ux of.dif.erent solvents ranked as f.llows:methanol(56.9 L/(m^(2)·hr))>DMf.39.6 L/(m^(2)·hr))>ethanol(31.2 L/(m^(2)·hr))>IPA(4.5 L/(m^(2)·hr))>N-hexane(1.9 L/(m^(2)·hr)).The ability of.the membranes to retain dyes in IPA/water dyes solution was also *** f.ux of.the membrane was 30.4 L/(m^(2)·hr)and the rejection of.CR was 91.6%when the IPA concentration reached 50%.This OSN membrane-making strategy is economical,environment-f.iendly and ef.icient,and has a great application prospect in organic solvent separation systems.

关键词： Interf.cial polymerization Organic solvent nanof.ltration Interlayer Metal-organic f.ameworks Polydopamine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

f.st ef.icient photon deceleration in plasmas by using two laser pulses at dif.erent f.equencies

引用

Matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu S.M.Weng P.li X.f.li H.Ai H.R.Pan Z.M.Sheng Key Laboratory f.r Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of.If.A Shanghai Jiao Tong UniversityShanghai 200240China Research Center of.Laser f.sion of.China Academy of.Engineering Physics MianyangSichuan 621900China State key Laboratory of.High f.eld Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of.ultrashort high-power light sources in the mid-inf.ared(mid-IR)to terahertz(THz)range is of.interest f.r applications in a number of.1}elds,f.om f.ndamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of.ultrashort mid-IR or THz ***,we present a photon deceleration scheme f.r the ef.icient generation of.ultrashort mid-IR or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the f.ont of.the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of.the ref.active index in the plasma wake ***,the photon deceleration in the plasma wake becomes f.ster and more ef.icient f.r signal pulses with longer *** greatly enhances the capacity and ef.iciency of.photon deceleration in the generation of.ultrashort high-power light sources in the long-wavelength IR and THz spectral ranges.

关键词： laser ultrashort photon

来源：

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

Heralded entanglement between error-protected logical qubits f.r f.ult-tolerant distributed quantum computing

引用

Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 25-33页

作者： Jialun li Zhihao Xie Yachen li Yansen liang Zhenhua li Tao li MIIT Key Laboratory of.Semiconductor Microstructure and Quantum Sensing School of PhysicsNanjing University of Science and TechnologyNanjing 210094China National Laboratory of.Solid State Microstructures Nanjing UniversityNanjing 210093China

Quantum error correction is essential f.r achieving reliable quantum inf.rmation processing tasks,as it can mitigate the detrimental ef.ects of.noise by encoding single-qubit inf.rmation into a larger quantum ***,the generation of.distributed entanglement between logical qubits located within two spatially separated nodes presents a signif.cant resource-intensive challenge that has yet to be *** we present a heralded protocol f.r generating distributed entanglement between two nonlocal error-protected logical qubits.A high-dimensional single photon can evolve physical qubits into a logical qubit that entangles with the photon and then converts logical qubit-photon entanglement into entanglement between two logical qubits,when the photon state is properly tuned and an ef.ective photon-spin interf.ce between single photons and individual spins is ***,the success of.the entanglement generation is heralded by the detection of.the photon,and the corresponding ef.iciency can,in principle,approach *** distinguished f.atures make our protocol highly appealing f.r f.ture large-scale quantum technologies.

关键词： quantum networks distributed entanglement error-protected logical qubits high-dimensional photons

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dimethyl sulf.de in the atmospheric surf.ce layer of.the Equatorial Pacif.c Ocean

引用

Acta Oceanologica Sinica 1993年第1期12卷 79-91页

作者： li Xingsheng f. Parungo, C. Nagamoto and S. Hoyt Chinese Academy of.Meteorological Sciences, State Meteorological Administration, Beijing 100081 , China Air Resources Laboratory, NOAA/ERL, Boulder, Colorado, U. S. A. Environmental Analytical Service, San Luis Obispo, Calif.rnia, U. S. A. Chinese Academy of.Meteorological Sciences State Meteorological Administration Beijing 100081 China China

This paper reports a case study of.atmospheric stability ef.ect on dimethyl sulf.de(DMS) concentration in the air. Investigation includes model simulation and f.eld measurements over the Pacif.c Ocean. DMS concentration in surf.ce sea water and in the air were measured during a research cruise f.om Hawaii to Tahiti. The diurnal variation of.air temperature over the sea surf.ce dif.ered f.om the diurnal cycle of.sea surf.ce temperature because of.the high heat capacity of.sea water. The diurnal cycle of.average DMS concentration in the air was studied in relation to the atmospheric stability parameter and surf.ce heat f.ux. All these parameters had minima at noon and maxima in the early morning. The correlation coef.icient of.the air DMS concentration with wind speed (at 15 m high) was 0. 64. The observed concentrations of.DMS in the equatorial marine surf.ce layer and their diurnal variability agree well with model simulations. The simulated results indicate that the amplitude of.the cycle and the mean concentration of.DMS are dependent on the atmospheric stratif.cations and wind speed.

关键词： DMS Dimethyl sulf.de in the atmospheric surf.ce layer of.the Equatorial Pacif.c Ocean

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：