检索结果-南通市图书馆

HYDRODYNAMIc FORcES FOR LARGE VERTIcAL cYLINDERS OF ARBITRARY SEcTION

在线全文

学校读者我要写书评

暂无评论

china Ocean engineering 1990年第2期5卷 145-158页

作者： Miao, guoping Liu, Yingzhong Shanghai Jiao Tong Univ Shanghai China

Some offshore structures have configurations as uniform vertical cylinders of equal section. The interaction between the oscillation of them and fluid motion is of importance in many design cases. For those special cylindrical bodies, a new type of local disturbance source is presented in the paper, which, being distributed on the sectional contour of the cylinders together with the known wave source, can be used to estimate the three-dimensional hydrodynamic forces on those cylinders of arbitrary section oscillating in still waters. The solution method both for wave forces and radiation forces is also discussed.

关键词： cylinders Wave Effects Hydrodynamics Fluid Structure Interaction Vibrations

New Method for Estimating Daily Global Solar Radiation over Sloped Topography in china

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sc.ences 2018年第3期35卷 285-295页

作者： guoping SHI Xinfa QIU Yan ZenG School of Geography and Remote Sensing Nanjing University of Information Science and Technology Nanjing 210044 China School of Applied Meteorology Nanjing University of Information Science and Technology Nanjing 210044 China jiangsu climate center Nanjing 210009 China

A new scheme for the estimation of daily global solar radiation over sloped topography in china is developed based on the Iqbal model c and MODIS cloud fraction. The effects of topography are determined using a digital elevation model. The scheme is tested using observations of solar radiation at 98 stations in china, and the results show that the mean absolute bias error is 1.51 MJ m-2 d-1 and the mean relative absolute bias error is 10.57%. Based on calculations using this scheme, the distribution of daily global solar radiation over slopes in china on four days in the middle of each season （15 January, 15 April, 15 July and 15 October 2003） at a spatial resolution of 1 km×1 km are analyzed. To investigate the effects of topography on global solar radiation, the results determined in four mountains areas （Tianshan, Kunlun Mountains, Qinling, and Nanling） are discussed, and the typical characteristics of solar radiation over sloped surfaces revealed. In general, the new scheme can produce reasonable characteristics of solar radiation distribution at a high spatial resolution in mountain areas, which will be useful in analyses of mountain climate and planning for agricultural production.

关键词： sloped terrain solar radiation topography geographic information system

Investigations of entrainment characteristics and shear-layer vortices evolution in an axisymmetric rear variable area bypass injector

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Aeronautics 2022年第4期35卷 230-244页

作者： guoping HUANG chao LI c.en XIA Qian LI college of energy and Power engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this study,firstly,for the axisymmetric RVABI,the change-rule of adverse pressure gradient caused by radial velocity during the transition of internal flow mode in variable geometry is summarized,and a Bypass Ratio(BR) iterative algorithm based on the empirical correlation of non-equilibrium pressure is *** algorithm can estimate the nonlinear relationship between area ratio and BR,with an error range falling below 6.5%.Then,we discuss the favorable effect of uniform mixing on the thrust augmentation of mixed exhaust under variable BR *** this point of view,the characteristics of vortices evolution in different shear strength jets are compared,to clarify the effect of variable cycle parameters on jet *** the results suggest,when ■ is as low as 0.22,the K-H disturbance is of high-frequency wavelet property,and it is difficult to induce large-scale spanwise *** macro migrations of fluid elements in span wise vortices and the diffusion effect caused by edge tearing is weak,which is not conducive to the energy exchange between the two ***,the low ■ jet will also correspondingly weaken the viscous dissipation effect of *** is concluded that the dissipation level is proportional to the 2.31 power of the ■.

关键词： Variable cycle engine Rear variable area bypass injector Bypass ratio adjustment Mixed exhaust Thermal mixing Spanwise vortex

Impact of Arctic Oscillation on cloud radiative forcing and September sea ice retreat

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2022年第10期41卷 131-139页

作者： Yanxing Li Liang chang guoping Gao college of Marine Sc.ences Shanghai Ocean UniversityShanghai201306China State Key Laboratory of Satellite Ocean environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China college of Marine Ecology and environment Shanghai Ocean UniversityShanghai201306China

The Arctic Oscillation(AO)has important effects on the sea ice change in terms of the dynamic and thermodynamic ***,while the dynamic processes of AO have been widely explored,the thermodynamic processes of AO need to be further *** this paper,we use the fifth state-of-the-art reanalysis at European centre for Medium-Range Weather Forecasts(ERA5)from 1979 to 2020 to investigate the relationship between AO and the surface springtime longwave(LW)cloud radiative forcing(cRF),summertime shortwave(SW)cRF in the Arctic region(65°-90°N).In addition,the contribution of cRF induced by AO to the sea ice change is also *** indicate that the positive(negative)anomalies of springtime LW cRF and summertime SW cRF are generally detected over the Arctic Ocean during the enhanced positive(negative)AO phase in spring and summer,***,while the LW(SW)cRF generally has a positive correlation with AO index(AOI)in spring(summer)over the entire Arctic Ocean,this correlation is statistically significant over 70°-85°N and 120°W-90°E(i.e.,region of interest(ROI))in both ***,the response of cRF to the atmospheric conditions varies in spring and *** also find that the positive springtime(summertime)AOI tends to decrease(increase)the sea ice in September,and this phenomenon is especially prominent over the *** sensitivity study among sea ice extent,cRF and AOI further reveals that decreases(increases)in September sea ice over the ROI are partly attributed to the springtime LW(summertime SW)cRF during the positive *** present study provides a new pattern of AO affecting sea ice change via cloud radiative effects,which might benefit the sea ice forecast improvement.

关键词： Arctic Arctic Oscillation cloud radiative forcing sea ice retreat

Vegetation Development and Water Level changes in Shenjiadian Peatland in Sanjiang Plain,Northeast china

在线全文

学校读者我要写书评

暂无评论

chinese Geographical Sc.ence 2015年第4期25卷 451-461页

作者： WANG chunling ZHAO Hongyan WANG guoping Key Laboratory of Wetland Ecology and environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of chinese Academy of Sc.ences Key Laboratory of Wetland Ecology and Vegetation Restoration Northeast Normal University

This paper documents a 7800-year proxy record from the Shenjiadian peatland on the Sanjiang Plain in Northeast ***-resolution plant macrofossil and colorimetric humification methods were used to reconstruct the vegetation and hydrologic history from a 193 cm-long sedimentary *** correspondence analysis(DcA) was applied to transform the raw plant macrofossil data into latent indices of peatland water *** vegetation community transited from an Equisetum fluviatile community to a carex lasiocarpa community at approximately 3800 cal yr BP and was followed by a carex-shrub community at approximately 480 cal yr *** on the plant macrofossil DcA axis 1 scores and humification values,we distinguished four hydrologic periods:a wet period from 7800 cal yr BP to 4500 cal yr BP,dry periods up to 1600 cal yr BP,drier periods until 300 cal yr BP,and the driest period from 300 cal yr BP until the *** a comparison with other climate records,we suggest that the East Asian summer monsoon(EAM) was the main driving force for vegetation and water level changes to the Shenjiadian peatland through its impacts on precipitation.

关键词： plant macrofossils humification Holocene peatland Northeast china

Stabilization for nonlinear systems via a limited capacity communication channel with data packet dropout

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第1期8卷 111-116页

作者： Lei ZHOU guoping LU School of Sc.ence Nantong University Nantong Jiangsu 226007 China Department of Mathematics East China Normal University Shanghai 200062 China college of Electrical engineering Nantong University Nantong Jiangsu 226019 China

This paper addresses the stabilization problem for a class of nonlinear systems. It is assumed that the controller can only receive the transmitted sequence of finite coded signals via a limited digital communication channel. Both state and output feedback coder-decoder-controller procedures are proposed. Stabilization conditions involving the size of coding alphabet, the sampling period, system state growth rate and data packet dropout rate are obtained. Finally, an example is given to illustrate the design procedures and effectiveness of the proposed results.

关键词： Stabilization Nonlinear system Limited information Data packet dropout Linear matrix inequality

TIME DOMAIN SOLUTION OF UNSTEADY FLOW AROUND A SHIP

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1998年第4期10卷 7-15页

作者： Li, Yile Liu, Yingzhong Miao, guoping Shanghai Jiaotong Univ Shanghai China

The unsteady flow around a ship advancing at a constant speed was studied in time domain by using a higher-order boundary element method. The Rankine source was employed. The ship hull and free surface were discretized into 8-node isoparametric elements. A modified Green formula was used to overcome the numerical difficulty arising from singular or quasi-singular integral equation. In the case of τ>0.25, a rigid wall condition was applied to the upstream and a numerical beach was applied to the downstream to absorb the outgoing waves. The numerical results are satisfactory compared with the experimental results.

关键词： Boundary element method computer simulation Flow of water Ships Time domain analysis Unsteady flow

AcTIVE cONTROL OF A FLEXIBLE cANTILEVER PLATE WITH MULTIPLE TIME DELAYS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2008年第3期21卷 257-266页

作者： Longxiang c.en Ji Pan guoping cai Department of engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

Active control of a flexible cantilever plate with multiple time delays is investigated using the discrete optimal control method. A controller with multiple time delays is presented. In this controller, time delay effect is incorporated in the mathematical model of the dynamic system throughout the control design and no approximations and assumptions are made in the controller derivation, so the system stability is easily guaranteed. Furthermore, this controller is available for both small time delays and large time delays. The feasibility and effic.ency of the proposed controller are verified through numerical simulations in the end of this paper.

关键词： flexible cantilever plate multiple time delays discrete optima l control

energy transfer, anticounterfeiting, white light emission and sensing in fine-regulating series of lanthanide metal-organic frameworks

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第3期42卷 446-454,I0001页

作者： Juanjuan Xue Yao Wang guoping Yang Yaoyu Wang Key Laboratory of Synthetic and Natural Functional Molecule chemistry of the Ministry of Education Shaanxi Key Laboratory of Physico-Inorganic ChemistryCollege of Chemistry&Materials ScienceNorthwest UniversityXi'an710127China

Three lanthanide ions and a rigid(1,1'-biphenyl)-2,4,6-tricarboxylic acid(H_(3)bptc) ligand led to the isostructural lanthanide metal-organic frameworks(Ln-MOFs) {[Ln(bptc)(H_(2)O)_(3)]·3H_(2)O}_n(Lnbptc, Ln = Eu,Tb, Gd, Eu_(x)Tb_(1—x), Eu_(x)Gd_(1-x), Tb_(x)Gd_(1-x), and Eu_(0.12)Tb_(0.52)Gd_(0.36)). The density functional theory(DFT) and time-dependent DFT calculation were expanded on H_3bptc, which point to the occurrence of “antenna effect”. The minor diameter samples of Eubptc, Tbbptc, and Gdbptc can also be attained via the microwave synthesis and employed for handwriting anticounterfeiting. Interestingly, the typical red emission of Eu^(3+) and green emission of Tb~(3+) could be fine-tuned by Gd^(3+) via chemical mixing to be full-color emissions bimetallic doped Eu_(x)Tb_(1-x)bptc, Eu_(x)Gd_(1-x)bptc, and Tb_(x)Gd_(1-x)bptc. The above synthetic bimetallic MOFs can be fixed in positioning boxes of quick response(QR) codes with diverse emission for anticounterfeiting. The message can be decoded under the irradiation of 365 nm ultraviolet lamp while invisible in the daylight. Notably, the trimetallic doped Eu_(0.12)Tb_(0.52)Gd_(0.36)bptc emits white light with the cIE color coordinate(0.34, 0.34). Furthermore, Tbbptc is demonstrated to be a sensitive probe toward nitrobenzene and acetone with multiple mechanisms.

关键词： Metal-organic frameworks Anticounterfeiting White light-emitting Sensing Rare earths