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ATMOSPHERIC TURBULENCE INTENSITY AND DIFFUSION PARAMETER OVER COMPLICATED TOPOGRAPHY OF EASTERN GUANGDONG 被引量:1
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作者 吴艳标 刘树旺 阳继宏 《Journal of Tropical Meteorology》 SCIE 1996年第2期181-188,共8页
ATMOSPHERICTURBULENCEINTENSITYANDDIFFUSIONPARAMETEROVERCOMPLICATEDTOPOGRAPHYOFEASTERNGUANGDONGWuYanbiao(吴艳标)... ATMOSPHERICTURBULENCEINTENSITYANDDIFFUSIONPARAMETEROVERCOMPLICATEDTOPOGRAPHYOFEASTERNGUANGDONGWuYanbiao(吴艳标);LiuShuwang(刘树旺)a... 展开更多
关键词 COMPLICATED TOPOGRAPHY ATMOSPHERIC DIFFUSION parameter TURBULENCE intensity
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Computation of Energy, Intensity and Thermodynamic Parameters for the Interaction of Ln(III) with Nucleic Acid: Analysis of Structural Conformations, Chemical Kinetics and Thermodynamic Behaviour through 4f-4f Transition Spectra as Probe
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作者 N. Bendangsenla T. Moainla +1 位作者 Juliana Sanchu M. Indira Devi 《Journal of Materials Science and Chemical Engineering》 2018年第7期169-183,共15页
Nucleosides and Nucleotides are polydentate ligands, offering potential binding sites for metal ions. Energy interaction parameters: Slater Condon Fk (cm-1), Spin Orbit interaction ξ4f? (cm-1), Nephelauxetic Ratio (... Nucleosides and Nucleotides are polydentate ligands, offering potential binding sites for metal ions. Energy interaction parameters: Slater Condon Fk (cm-1), Spin Orbit interaction ξ4f? (cm-1), Nephelauxetic Ratio (β), Bonding (b1/2) and Covalency (δ) parameter for the interaction of Pr(III) with Nucleoside and Nucleotide are evaluated to study the mode of binding of the Nucleic Acid Components (Guanosine and Guanosine Triphosphate) with Pr(III). Further Intensity Parameters like Oscillation Strength and Judd Ofelt Parameter (T2, T4, T6) have been evaluated to investigate degree of inner or outer sphere co-ordination of Pr(III) with Nucliec Acid ligands. Comperative Absorption Spectra in different solvents substantiate the informations, gathered from the evaluated values of both energy interaction and intensity parameters. Further evaluation of Thermodynamic parameters (ΔG, ΔH and ΔS) through Kinetic studies enable to provide the detailed information about the reaction pathways and thermodynamic behavour of the complexation process of neucleosides and nucleotides with Pr(III) and Ca2+. 展开更多
关键词 Nucleic Acid 4f-4f TRANSITION SPECTRA Nephelauxetic Effect judd-ofelt parameters Slator Condon Reaction Rate Thermodynamic
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Altitude and intensity characteristics of parametric instability excited by an HF pump wave near the fifth electron harmonic
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作者 吴军 吴健 +3 位作者 M T RIETVELD I HAGGSTROM 赵海生 许正文 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第12期50-56,共7页
An ionospheric heating experiment involving an O mode pump wave was carried out at European Incoherent Scatter Scientific Association site in Troms?. The observation of the ultra high frequency radar illustrates the ... An ionospheric heating experiment involving an O mode pump wave was carried out at European Incoherent Scatter Scientific Association site in Troms?. The observation of the ultra high frequency radar illustrates the systematic variations of the enhanced ion line and plasma line in altitude and intensity as a function of the pump frequency. The analysis shows that those altitude variations are due to the thermal effect, and the intensity variations of the enhanced ion line are dependent on whether or not the enhanced ion acoustic wave satisfy the Bragg condition of radar. Moreover, a prediction that if the enhancement in electron temperature is suppressed,those systematic variations will be absent, is given. 展开更多
关键词 ionospheric heating fifth harmonic parameter instability altitude intensity
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基于Wave Intensity技术的高血压患者动脉弹性参数与血瘀证积分的相关性分析 被引量:8
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作者 魏世超 骆杰伟 +7 位作者 陈玮吉 林宁 郑星宇 李建卫 任林 孟晓嵘 张莹莹 黄昉萌 《世界中西医结合杂志》 2012年第5期407-409,共3页
目的探讨应用Wave Intensity(WI)技术检测高血压患者动脉弹性参数与血瘀证积分的相关性。方法用ALOKA Prosoundα10彩色多普勒超声仪检测119例高血压基础病患者,及62例健康对照者,获取颈总动脉β(僵硬度)、Ep(弹性模量)、AC(顺应性)、AI... 目的探讨应用Wave Intensity(WI)技术检测高血压患者动脉弹性参数与血瘀证积分的相关性。方法用ALOKA Prosoundα10彩色多普勒超声仪检测119例高血压基础病患者,及62例健康对照者,获取颈总动脉β(僵硬度)、Ep(弹性模量)、AC(顺应性)、AI(增大指数)、PWVβ(β值推导的脉搏波传导速度)、PWV-WI(WI值推导的脉搏波传导速度)等数据,并评估血瘀证积分。结果高血压组β、Ep、AI、PWVβ、PWV-WI均值均高于对照组均值,而AC均值低于对照组均值,两组比较差异有统计学意义(P<0.05),而高血压血瘀证积分与β、Ep、PWVβ、PWV-WI值与呈正相关(分别为r=0.750,P<0.001;r=0.776,P<0.001;r=0.870,P<0.001;r=0.418,P<0.001),与AC呈负相关(r=-0.769,P<0.001),差异有统计学意义,血瘀证积分与AI无明显相关(r=0.023,P=0.800)。结论基于Wave Intensity技术检测的动脉弹性参数能较准确反映血瘀证程度,具有临床应用价值。 展开更多
关键词 WAVE intensity 超声检查 高血压 血瘀证 动脉弹性参数
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The influence of cation additives on the NIR luminescence intensity of Er~(3+)-doped borate glasses 被引量:1
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作者 周永亮 张晓松 +4 位作者 徐建萍 张忠朋 张高峰 魏凤巍 李岚 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期398-402,共页
Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/... Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency. 展开更多
关键词 maximal phonon density of state judd-ofelt intensity parameter Er3+-doped borate glasses
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Some considerations on the physical mea-sure of seismic intensity 被引量:1
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作者 郝敏 谢礼立 徐龙军 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第2期245-250,255,共7页
The study on seismic intensity can be traced prior to the time that modern seismology was established. In its early stage the seismic intensity was designed to serve as a measure in scaling the severity of earthquake ... The study on seismic intensity can be traced prior to the time that modern seismology was established. In its early stage the seismic intensity was designed to serve as a measure in scaling the severity of earthquake damage to civil engineering and environmental structures. Also the seismic intensity is usually assigned by engineers and seismologists with one or two characteristic parameters of earthquake ground motions to reflect earthquake damage potential so as to be able to serve as an input earthquake load for seismic design of structures. So choosing a proper parameter to reflect the action of seismic intensity is the main objective of the research on physical measure of seismic intensity. However, since various kinds of structures have quite different damage mechanisms, there will exist great differences in damages to different structures located at the same area during the same earthquake. Particularly, in some cases, quite different damages have happened even to the structures of same kind due to many other factors such as different construction materials, different configurations or on the different types of sites where structures located. In addition, the ground motion parameters, which result in damage to structures, are not the single peak value of ground motion. Hence, this paper emphasizes that the research on new physical measure of seismic intensity should not only consider the structural characteristics but also take into account other parameters such as duration, energy of ground motion and so on. In particular, as the physical measures of intensity, different ground motion parameter should be adopted for different structures. 展开更多
关键词 seismic intensity earthquake potential damage earthquake damage to structures physical measure of seismic intensity earthquake ground motion parameters
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Transition intensity calculation of Yb:YAG 被引量:1
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作者 张洪波 张庆礼 +4 位作者 王星 孙贵花 王小飞 张德明 孙敦陆 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第6期448-453,共6页
The Yb:YAG is an excellent high-average power and ultra-short pulse laser crystal. Transition intensity parameters A(tp)~k and Huang–Rhys factors are fitted to its emission spectrum by the full-profile fitting met... The Yb:YAG is an excellent high-average power and ultra-short pulse laser crystal. Transition intensity parameters A(tp)~k and Huang–Rhys factors are fitted to its emission spectrum by the full-profile fitting method. Calculated results indicate that the emission spectrum of Yb:YAG at cryogenic temperature consists of three pure electron state transitions and two phononassisted transitions, one vibronic transition releases one-phonon of 3 cm^(-1), and the other vibronic transition absorbs onephonon of 22 cm^(-1). At 300 K, the phonon assisted transition of 3 cm^(-1) turns into two-or more-phonon assisted transitions.The procedure absorbing phonon can reduce the thermal load of Yb:YAG and improve the laser efficiency, which may be one of the reasons why Yb:YAG has excellent performance. The emission bands of Yb:YAG are broadened thermally, and the peak values decrease by several times. The emission cross sections of Yb:YAG determined by Fuchtbauer–Ladenburg(F–L) formula are remarkably different from those calculated with A(tp)~k, which indicates that it is necessary for a laser material to determine its transition intensity parameters A(tp)~kin order to reasonably evaluate the laser performance. 展开更多
关键词 transition intensity parameters rare earth PHOTOLUMINESCENCE Yb^3+ :YAG
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Spectral Parameters of Nd^(3+) Ion in Nd^(3+):NaGd(MoO_4)_2 Crystal 被引量:1
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作者 李修芝 王国富 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第4期392-394,共3页
The spectral parameters of Nd^3+ ions in Nd^3+-doped NaGd(MoO4)2 crystal have been investigated based on Judd-Ofelt theory and obtained as follows: The intensity parameters Ωeff are Ω2 = 24.77×10^20, Ω4 =... The spectral parameters of Nd^3+ ions in Nd^3+-doped NaGd(MoO4)2 crystal have been investigated based on Judd-Ofelt theory and obtained as follows: The intensity parameters Ωeff are Ω2 = 24.77×10^20, Ω4 = 7.31×10^-20 and Ω6 = 6.91×10^-20 cm^2. The radiative lifetime is 100 μs, and the quantum efficiency is 93.9%. The fluorescence branch ratios were calculated to be β1 = 0.441, β2 = 0.469,β3 = 0.086 and β4=0.004. 展开更多
关键词 spectral parameters judd-ofelt theory Nd^3+:NaGd(MoO4)2 solid-state laser materials
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Kurtosis parameters of super Lorentz-Gauss beams through a paraxial and real ABCD optical system
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作者 周国泉 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期233-240,共8页
Based on the propagation equation of higher-order intensity moments, analytical propagation expressions for the kurtosis parameters of a super Lorentz-Gauss (SLG) SLG01 beam through a paraxial and real ABCD optical ... Based on the propagation equation of higher-order intensity moments, analytical propagation expressions for the kurtosis parameters of a super Lorentz-Gauss (SLG) SLG01 beam through a paraxial and real ABCD optical system are derived. By replacing the parameters in the expressions of the kurtosis parameters of the SLC01 beam, the kurtosis parameters of the SLG10 and SLGll beams through a paraxial and real ABCD optical system can be easily obtained. The kurtosis parameters of an SLG01 beam through a paraxial and real ABCD optical system depend on two ratios. One is the ratio of the transfer matrix element B to the product of the transfer matrix element A and the diffraction-free range of the super-Lorentzian part. The other is the ratio of the width parameter of the super-Lorentzian part to the waist of the Gaussian part. As a numerical example, the properties of the kurtosis parameters of an SLG01 beam propagating in free space are illustrated. The influences of different parameters on the kurtosis parameters of an SLG01 beam are analysed in detail. 展开更多
关键词 super Lorentz-Gauss beam kurtosis parameter intensity moment
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Optical parameters and energy levels splitting of Ho^(3+) in Ho^(3+): GdVO_4
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作者 王策 陈晓波 +8 位作者 张春林 张蕴芝 刘金英 王亚非 刘大禾 杜帅 徐小灵 王磊 李崧 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第12期4656-4664,共9页
Ho^3+ : GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3+ in the sample Ho^3+: GdVO4. The intensity parameters are calculated by using t... Ho^3+ : GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3+ in the sample Ho^3+: GdVO4. The intensity parameters are calculated by using the Judd-Ofelt theory. Some predicted spectroscopic parameters, such as the spontaneous radiative transition rate, branching ratio and integrated emission cross section are dealt with. And we also compare the optical parameters with those of other materials. From these results, it is found that there are many transitions which have large oscillator strengths and large integrated emission cross sections. Especially the transitions such as ^5 F4 → ^5 I 8, ^5 S2→^5 I8, ^5 F5 → ^5 I8 and ^5 I7 →^ 5 I8 are useful in solid-state lasers and other fields. Finally, we discuss the splitting of the energy levels of Ho^3+ in the crystal GdVO4 based on the group theory. 展开更多
关键词 Ho^3+: GdVO4 absorption spectrum intensity parameters laser material
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Spectral Parameters of Nd^(3+) in the Nd^(3+):GdMgB_5O_(10) Crystal
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作者 FANJun-Mei LINZhou-Bin ZHANGLi-Zhen HUZu-Shu WANGGuo-Fu 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第4期419-423,共5页
The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.5... The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2. 展开更多
关键词 spectral parameters Nd3+:GdMgB5O10 crystal judd-ofelt theory
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Spectral Parameters of Nd^(3+) Ion in Nd^(3+):KLu(WO_4)_2 Crystal
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作者 TANGLi-Yong WANGGuo-Fu 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第4期383-386,共4页
The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20... The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20 cm2 and ?6 = 3.1189×10-20 cm2; the radiative lifetime is 123 μs; the quantum efficiency is equal to 64.55%; and β1 = 0.5498, β2 = 0.3943, β3 = 0.0551 and β4 = 0.0027 for the fluorescence branch ratios. 展开更多
关键词 spectral parameters Nd3+:KLu(WO4)2 crystal judd-ofelt theory
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Bubble dynamics characteristics and influencing factors on the cavitation collapse intensity for self-resonating cavitating jets
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作者 PENG Kewen TIAN Shouceng +3 位作者 LI Gensheng HUANG Zhongwei YANG Ruiyue GUO Zhaoquan 《Petroleum Exploration and Development》 2018年第2期343-350,共8页
Based on bubble dynamics theory, a mathematic model describing the cavitation bubble size variation in the flow field of self-resonating cavitating jet was developed considering the pressure field and mass and heat ex... Based on bubble dynamics theory, a mathematic model describing the cavitation bubble size variation in the flow field of self-resonating cavitating jet was developed considering the pressure field and mass and heat exchange between cavitation bubble and ambient fluid. With this model, the influence factors on the cavitation intensity are investigated. The results show that the destructiveness of cavitating jet in breaking rocks depends on the bubble's first collapse, with decreasing intensity in the subsequent collapses. The self-resonating effect significantly enhances the cavitation intensity by promoting the collapse pressure and elongating its duration. Hydraulic parameters are proven to be the dominating factors influencing cavitation intensity: while collapse intensity monotonously increases with jet velocity, there exists an optimum ambient pressure where highest collapse intensity can be achieved. Conversely, the fluid properties show minor influences: cavitation intensity only slightly decreases with the increasing of fluid's density and barely changes with the variation of viscosity and surface tension. The results from this investigation help to uncover the mechanism of the enhanced erosion potential of self-resonating cavitating jet. The conclusions can be used to further improve the performance of self-resonating cavitating jet in field applications. 展开更多
关键词 self-resonating cavitating JET cavitating BUBBLE COLLAPSE intensity hydraulic parameters fluid properties
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Intensity Retrieved from Public Monitoring Video——Cases from the May 12,2008,Wenchuan Earthquake 被引量:1
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作者 Yang Xiaolin Wu Zhongliang Xia Min 《Earthquake Research in China》 2008年第3期229-236,共8页
Macroseismic investigation is presented with a new potential means of investigation in the "digital age". In this paper we studied several cases in the May 12, 2008, Wenchuan M_S8.0 earthquake with a view to... Macroseismic investigation is presented with a new potential means of investigation in the "digital age". In this paper we studied several cases in the May 12, 2008, Wenchuan M_S8.0 earthquake with a view to exploring the feasibility of retrieving intensity, or even strong ground motion parameters, from public monitoring video which was originally deployed for security purposes. We used public monitoring video records from 44 sites across the meizoseismal region and its surroundings to estimate the intensity. By using the video from a bank in Dujiangyan, Sichuan Province and making the simple assumption that ground vibration is in the form of a propagating harmonic wave, we estimated that the local ground motion acceleration was 0.14g. 展开更多
关键词 地震 公共场所 参数 参量 监测
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DICE:An open-source MATLAB application for quantification and parametrization of digital outcrop model-based fracture datasets
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作者 Niccolò Menegoni Daniele Giordan +1 位作者 Riccardo Inama Cesare Perotti 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第5期1090-1110,共21页
An open-source MATLAB application(app)named Discontinuity Intensity Calculator and Estimator(DICE)was developed in order to quantitatively characterize the fractures,or in more general,discontinuities within a rocky o... An open-source MATLAB application(app)named Discontinuity Intensity Calculator and Estimator(DICE)was developed in order to quantitatively characterize the fractures,or in more general,discontinuities within a rocky outcrop in three-dimensional(3D)digital data,such as digital outcrop model(DOM).The workflow proposed for the parametrization of the discontinuities consists of the following steps:(1)Analysis and mapping of the fractures detected within the 3D DOMs;(2)Calculation of the orientation,position and dimensions of discontinuities that are represented by best-fit circular planes;(3)Determining the discontinuity parameters(dimension,distribution,spacing and intensity)by the DICE algorithm using different 3D oriented sampling techniques(3D oriented scanline,3D oriented circular scan window and spherical scan volume).Different sampling methods were bench tested with a synthetic,as well as a natural case study,and compared in order to understand the advantages and limitations of each technique.The 3D oriented circular scan window appears to be the most effective method for fracture intensity estimation with high accuracy(error 0.4%)and stability with variations in scan radius. 展开更多
关键词 Fracture parameter DISCONTINUITY Fault Fracture intensity Linear fracture intensity(P10) Areal fracture intensity(P21) Volumetric fracture intensity(P32)
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Linkage intensity learning approach with genetic algorithm for causality diagram
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作者 WANG Cheng-liang CHEN Juan-juan 《Journal of Chongqing University》 CAS 2007年第2期135-140,共6页
The causality diagram theory, which adopts graphical expression of knowledge and direct intensity of causality, overcomes some shortages in belief network and has evolved into a mixed causality diagram methodology for... The causality diagram theory, which adopts graphical expression of knowledge and direct intensity of causality, overcomes some shortages in belief network and has evolved into a mixed causality diagram methodology for discrete and continuous variable. But to give linkage intensity of causality diagram is difficult, particularly in many working conditions in which sampling data are limited or noisy. The classic learning algorithm is hard to be adopted. We used genetic algorithm to learn linkage intensity from limited data. The simulation results demonstrate that this algorithm is more suitable than the classic algorithm in the condition of sample shortage such as space shuttle’s fault diagnoisis. 展开更多
关键词 因果图表 遗传算法 计算方法 人工智能系统
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STUDY ON AUTOMATIC POLISHING AT CONSTANT PRESSURE INTENSITY
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作者 Zhao Ji(Jilin University of TechnologyKondo T Narahara H Igarashi S Saito kHokkaido University, Japan) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1994年第4期296-302,共17页
Through theoretical and experimental researeh about automatic polishing on thecurved surfaces of the moulds, the limitation of the polishing method at constant pressure, whichis adopted widely in the world, is analyse... Through theoretical and experimental researeh about automatic polishing on thecurved surfaces of the moulds, the limitation of the polishing method at constant pressure, whichis adopted widely in the world, is analysed. Based on the analysis, a new polishing method atconstant pressure intensity is proposed, and the corresponding goveming equation and a com-prehensive polishing parameter are given as well. 展开更多
关键词 Mould curved surface Polishing at constant pressure intensity Comprehensive polishing parameter
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考虑渗吸效应的页岩油井体积压裂用液强度优化方法——以南襄盆地泌阳凹陷X-1井为例
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作者 蒋廷学 沈子齐 +6 位作者 王良军 齐自立 肖博 秦秋萍 范喜群 王勇 曲海 《石油勘探与开发》 EI CAS CSCD 北大核心 2024年第3期588-596,共9页
以南襄盆地泌阳凹陷X-1井为例,将岩心实验测得的带压渗吸规律通过岩心尺度油藏模拟拟合得到表征渗吸过程的毛管压力特征曲线及相对渗透率特征曲线,将其代入宏观油藏模型中模拟压后焖井过程,建立体积压裂用液强度优化方法。研究表明:压... 以南襄盆地泌阳凹陷X-1井为例,将岩心实验测得的带压渗吸规律通过岩心尺度油藏模拟拟合得到表征渗吸过程的毛管压力特征曲线及相对渗透率特征曲线,将其代入宏观油藏模型中模拟压后焖井过程,建立体积压裂用液强度优化方法。研究表明:压裂液用液强度的优化必须考虑造缝要满足预测最终可采储量的需求、满足渗吸驱油的需求、满足补充地层能量的需求,同时将压裂液用液强度控制在临界渗吸强度附近,避免液量过少导致渗吸置换作用不充分,液量过大导致成本增加与潜在储层伤害。模拟发现,压裂液用液强度与单井预测最终可采储量正相关且存在最优值,大于最优值后,单井预测最终可采储量增加的幅度将越来越小,通过适当提高压裂液用液强度补充地层能量提高焖井压力,适当增加焖井时间,可有效增加压后产能。经过X-1井现场试验验证,该优化方法对油井生产效果改善显著,具有较好的实用性。 展开更多
关键词 页岩油 水平井 体积压裂 渗吸效应 用液强度 参数优化
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泥岩卸荷力学行为、声发射特征及能量演化研究
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作者 张良泉 刘建锋 +1 位作者 裴建良 刘怀忠 《三峡大学学报(自然科学版)》 CAS 北大核心 2024年第2期47-54,共8页
为了更好地探究水利水电工程地下开挖施工时泥岩损伤演化,利用四川大学MTS 815混凝土与岩石力学试验系统开展泥岩三轴卸荷试验,试验共设置3种围压(10,20,25 MPa),采用加围压-恒围压加轴压-加轴压卸围压的方式加载,同步进行声发射数据采... 为了更好地探究水利水电工程地下开挖施工时泥岩损伤演化,利用四川大学MTS 815混凝土与岩石力学试验系统开展泥岩三轴卸荷试验,试验共设置3种围压(10,20,25 MPa),采用加围压-恒围压加轴压-加轴压卸围压的方式加载,同步进行声发射数据采集,从力学行为、声发射特征和能量演化的角度分析试验结果.结果表明:围压越高,卸载后对试样的影响越大,泥岩的体积膨胀特性更显著,试样破坏时的卸荷比更小,弹性应变能和耗散能的增速越快.随着卸荷比增大,泥岩的变形模量会先增大后减小,内摩擦角、黏聚力、剪胀角增大,弹性应变能增大,耗散能先增大后趋于稳定甚至下降.在峰值应力出现前会出现声发射振铃计数率的高值,围压的增大会延缓声发射活跃期的出现,同时声发射累计计数与能量会增加. 展开更多
关键词 泥岩 卸荷 变形模量 强度参数 声发射 能量演化
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国家中心地震烈度速报与预警技术平台
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作者 张建勇 席楠 +3 位作者 徐泰然 戴丹青 孙丽 梁建宏 《中国地震》 北大核心 2024年第1期54-68,共15页
震后快速获取发震信息和灾区受灾情况,对于降低生命和财产损失、震后灾害评估和救援决策至关重要。得益于国家地震烈度速报与预警工程的实施,中国地震台网中心建立了国家中心地震烈度速报与预警技术平台。通过该平台汇集并交换全国预警... 震后快速获取发震信息和灾区受灾情况,对于降低生命和财产损失、震后灾害评估和救援决策至关重要。得益于国家地震烈度速报与预警工程的实施,中国地震台网中心建立了国家中心地震烈度速报与预警技术平台。通过该平台汇集并交换全国预警实时波形,分析、判断、加工实时波形数据,及时产出地震预警、烈度速报、地震基本参数和震源参数等信息产品,并将其推送到紧急信息服务系统,实现秒级地震预警、分钟级参数速报和烈度速报,在泸定MS6.8等强震袭来时均成功发布预警信息,为防震减灾及应急救援等提供有力保障。本文详细介绍该平台的整体情况及其所包含的分系统功能,并讨论目前平台的技术特性和需要改进的问题。 展开更多
关键词 地震预警 烈度速报 参数速报 融合决策
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