检索结果-南通市图书馆

EI NIO PHENOMENON AND EXTENDED ASSOCIATE PATTERN ANALYSIS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2004年第1期16卷 90-100页

作者： CUIMao-chang MOJun QIAOFang-li InstituteofOceanology ChineseAcademyofSciences.Qingdao266071China／KeyLaboratoryofMarineScienceandNumericalmodelingTheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China. InstituteofOceanology ChineseAcademyofSciences.Qingdao266071China keylaboratoryofMarineScienceandNumericalmodeling TheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China

To study the causes of El Nino Phenomenon the Extended Associate PatternAnalysis (EAPA) is set up with monthly sea surface wind stress and precipitation besides Sea LevelPressure (SLP) and Sea Surface Temperature (SST) in or over the Pacific and related seas since 1979in present paper. The results show that El Nino Phenomenon means a SST redistribution, coveringalmost the whole Pacific that needs a huge amount of energy provided by air-sea interaction in themost Pacific regions; It is the wester burst and wind convergence, coming from meddle latitudesdirectly, instead of Kelvin waves that produce the strong SST warm signal in Nino regions; Twonegative SLP anomalies in middle of the North and South Pacific, most likely produced by the averageair pressure decreasing effect of explosive cyclones through precipitation, and the positive SLPanomaly o-ver the Asia-Australia land bridge, coming mainly from the south hemisphere with a littleinfluence from the Asian continent, are the three major causes for El Nino onset, they work togetherto produce anomalous wind convergence in Nino regions and wester burst in middle of the North andSouth Pacific that result in a warm tongue and cold pincers gearing together; Basically, during itsearly stage the ocean is forced by the atmosphere, while during its late stage the atmosphere isforced by the ocean.

关键词： extended associate pattern analysis (EAPA) El nino phenomenon

Light collection of the POLAR detector

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,LI YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,chinese academy of sciences,beijing 100049,china 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-350 *** light collection of 200 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4×4 bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

SVOM gamma ray monitor

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,chinese academy of sciences,beijing 100049,china 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

The effects of shock wave and quasi-traveling wave in the mechanical impact test

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2010年第9期53卷 2535-2541页

作者： WU Mei1,5,SUN ZhongFeng2,ZHANG LuMei3,CHEN Yong1 & JI LinHong4 1 Institute of High energy Physics,chinese academy of sciences,beijing 100049,china 2 School of Mathematical sciences,Peking University,beijing 100871,china 3 High School of Central University for Nationalities,beijing 100081,china 4 Institute of Mechanical Design,Department of Precision Instruments and Mechanology,Tsinghua University,beijing 100084,china 5 academy of Opto-electronics,chinese academy of sciences,beijing 100190,china 1. Institute of High energy Physics Chinese Academy of Sciences Beijing 100049 China5. Academy of Opto-electronics Chinese Academy of Sciences Beijing 100190 China2. School of Mathematical Sciences Peking University Beijing 100871 China3. High School of Central University for Nationalities Beijing 100081 China4. Institute of Mechanical Design Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China

It is well-known that the numerical value is always larger than the measured value,amounting to many times,if we calculate the stress of the specimen in the impulse test using the NASTRAN and ANSYS (N-A) *** believe that the impact induces shock wave or quasi-traveling wave in the specimen,which can qualitatively explain the discrepancy of the two *** order to verify it,the Lax-Friedrichs (L-F) scheme is taken to simulate the transmission of shock wave and quasi-traveling wave in *** results show that the action area of the stress wave is small and the action time is very short,so the resulting stress and actual work are not *** addition,the distribution of the impact values obtained by the numerical simulation is in accordance with the trend of the measured impact values.

关键词： aerospace environment test shock wave quasi-traveling wave

MELTING CRYSTALLIZATION BEHAVIOR OF NYLON 66

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2001年第3期19卷 237-246页

作者： Qing-xin Zhang Zhi-shen Mo State key laboratory of Polymer Physics & Chemistry Changchun Institute of Applied Chemistry chinese academy of sciences, Changchun 130022, china chinese Acad Sci Changchun Inst Appl Chem State Key Lab Polymer Phys & Chem Changchun 130022 Peoples R China

Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 66. In the isothermal crystallization process, mechanisms of spherulitic nucleation and growth were discussed. The lateral and folding surface free energies determined from the Lauritzen-Hoffman treatment are sigma = 9.77 erg/cm(2) and sigma (e) = 155.48 erg/cm(2), respectively; and the work of chain folding is q = 33.14 kJ/mol. The nonisothermal crystallization kinetics of nylon 66 was analyzed by using the Mo method combined with the Avrami and Ozawa equations. The average Avrami exponent (n) over bar was determined to be 3.45. The activation energies (DeltaE) were determined to be -485.45 kJ/mol and -331.27 kJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius and the Kissinger methods.

关键词： nylon 66 crystallization kinetics activation energy

Properties of the 3/2^-[521] band in the odd-N rare-earth nuclei

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2011年第S1期54卷 37-43页

作者： CHEN Liang1,2, ZHOU XiaoHong1,2, ZHANG YuHu1, ZHANG ShuangQuan3 & ZHU LiHua4 1Institute of Modern Physics, chinese academy of sciences, Lanzhou 730000, china 2Graduate University of chinese academy of sciences, beijing 100049, china 3State key laboratory of Nuclear Physics and Technology, School of Physics, Peking University, beijing 100871, china 4china Institute of Atomic energy, beijing 102413, china 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing 100871 China4. China Institute of Atomic Energy Beijing 102413 China

High-spin states in 161Er have been studied experimentally via the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. Three rotational bands built on the 5/2+[642], 3/2-[521], and 11/2-[505] configurations have been extended up to high-spin states, and particularly, the α = -1/2 branch of the ground state 3/2-[521] band has been revised significantly. It is found that signature inversion occurs in the 3/2-[521] band after the band crossing in 161Er. The systematics of the signature inversion associated with the 3/2-[521] configuration in the rare-earth region is discussed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and a triaxial deformation is proposed to the 3/2-[521] band.

关键词： high-spin states signature inversion triaxial particle-rotor model

ADAPTIVE VARIABLE STRUCTURE CONTROLLERS AND APPLICATION TO ENGINE IDLE SPEED CONTROL SIMULATION

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Mechanical Engineering 2003年第2期16卷 171-174页

作者： Hui Qing Quyang MinggaoState key laboratory of AutomotiveSafety and energy,Tsinghua University,beijing 100084, china State key laboratory of Automotive Safety and energy Tsinghua University Beijing 100084 China

A neural-network-based adaptive variable structure control methodology isproposed for the tracking problem of nonlinear discrete-time input-output systems. The unknowndynamics of the system are approximated via radial basis function neural networks. The control lawis based on sliding modes and simple to implement. The discrete-time adaptive law for tuning theweight of neural networks is presented using the adaptive filtering algorithm with residueupper-bound compensation. The application of the proposed controller to engine idle speed controldesign is discussed. The results indicate the validation and effectiveness of this approach.

关键词： variable structure control adaptive control neural networks nonlineardiscrete-time systems idle speed control

Quantifying the effectiveness of SiO_2/Au light trapping nanoshells for thin film poly-Si solar cells

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2010年第8期53卷 2228-2231页

作者： BAI YiMing 1 ,WANG Jun 2 ,CHEN NuoFu 1,3 ,YAO JianXi 1 ,YIN ZhiGang 3 ,ZHANG Han 3 , ZHANG XingWang 3 ,HUANG TianMao 3 ,WANG YanShuo 3 &YANG XiaoLi 3 1School of Renewable energy Engineering,North china Electric power University,beijing 102206,china 2 National Engineering Research Center for Optoelectronic Devices,Institute of Semiconductors, chinese academy of sciences,PO Box 912,beijing 100083,china 3 key laboratory of Semiconductor Materials Science,Institute of Semiconductors, chinese academy of sciences,PO Box 912,beijing 100083,china 1. School of Renewable energy Engineering North China Electric Power University Beijing 102206 China2. National Engineering Research Center for Optoelectronic Devices Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 China3. Key Laboratory of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences PO Box 912 Beijing 100083 China

In order to enhance light absorption of thin film poly-crystalline silicon(TF poly-Si)solar cells over a broad spectral range, and quantify the effectiveness of nanoshell light trapping structure over the full solar spectrum in theory,the effective photon trapping flux(EPTF)and effective photon trapping efficiency(EPTE)were firstly proposed by considering both the external quantum efficiency of TF poly-Si solar cell and scattering properties of light trapping *** EPTF,EPTE and scattering spectrum exhibit different behaviors depending on the geometric size and density of nanoshells that form the light trapping *** an optimum size and density of SiO2/Au nanoshell light trapping layer,the EPTE could reach up to 40%due to the enhancement of light trapping over a broad spectral range,especially from 500 to 800 nm.

关键词： thin film poly-crystalline silicon surface plasmons SiO2/Au nanoshell

Laser Remelting of Plasma Sprayed NiCrAlY and NiCrAlY-Al_2O_3 Coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第5期17卷 525-528页

作者： Yingna WU, Gang ZHA NC, Bingchun ZHANG, Zhongchao FENG and Yong LIANG Institute of Metal Research, chinese academy of sciences, Shenyang 110016, china Fangjun LIU key laboratory for High energy Density Beam Processing Technology, beijing Aeronautical Manu chinese Acad Sci Inst Met Res Shenyang 110016 Peoples R China beijing Aeronaut Mfg Technol Res Inst Key Lab High Energy Dens Beam Proc Technol Beijing 100024 Peoples R China

Two types of plasma sprayed coatings (NiCrAlY and NiCrAlY-A12O3) were remelted by a 5 kW cw CO2 laser. With increasing laser power and decreasing traverse speed in the ranges of 200-700 W and 5-30 mm/s respectively, the melted track grew in width and depth. In the optimum range of laser parameters, a homogeneous remelted layer without voids, cavities, unmelted particles and microcracks was formed. On the surface of remelted layers, Al203 and YAIO3 were detected. As a result of isothermal oxidation tests, weight gains of laser remelted coatings were obviously lower than that only plasma sprayed, especially laser remelted NiCrAlY-Al2O3 coatings. The effects of laser remelting and incorporation of A12O3 second phase in N1CrAlY matrix on high temperature oxidation resistance were discussed.

关键词： Ni Laser Remelting of Plasma Sprayed NiCrAlY and NiCrAlY-Al2O3 Coatings TBCS Al