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FEM Analysis of Physical Field in Level Rolling Process of Inversion Casting by ANSYS Program 被引量:3
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作者 ZHAO Hong-liang GUAN Ren-guo WEN Jing-lin 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2000年第1期14-16,共3页
The strain physical field in level rolling process of inversion casting was analyzed by ANSYS program.Plastic strain,stress and displacement were gained.The results show that only surface strain takes place) the maxim... The strain physical field in level rolling process of inversion casting was analyzed by ANSYS program.Plastic strain,stress and displacement were gained.The results show that only surface strain takes place) the maximum stress exists in the geometrical deformation zone;In the deformation transition zone and the part leaving the rollers,different stress exists.The rolling force estimated with ANSYS program corresponds to those measured. 展开更多
关键词 inversion casting level rolling FEM ANSYS progra m
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Three-dimensional inversion of knot defects recognition in timber cutting
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作者 Yizhuo Zhang Dapeng Jiang +1 位作者 Zebing Zhang Jinhao Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期1145-1152,共8页
The comprehensive utilization of wood is the main goal of log cutting,but knot defects increase the diffi-culty of rationally optimizing cutting.Due to the lack of real shape data of knot defects in logs,it is diffi c... The comprehensive utilization of wood is the main goal of log cutting,but knot defects increase the diffi-culty of rationally optimizing cutting.Due to the lack of real shape data of knot defects in logs,it is diffi cult for detection methods to establish a correlation between signal and defect morphology.An image-processing method is proposed for knot inversion based on distance regularized level set segmentation(DRLSE)and spatial vertex clustering,and with the inversion of the defects existing relative board position in the log,an inversion model of the knot defect is established.First,the defect edges of the top and bottom images of the boards are extracted by DRLSE and ellipse fi tting,and the major axes of the ellipses made coplanar by angle correction;second,the coordinate points of the top and bottom ellipse edges are extracted to form a spatial straight line;third,to solve the intersection dispersion of spatial straight lines and the major axis plane,K-medoids clustering is used to locate the vertex.Finally,with the vertex and the large ellipse,a 3D cone model is constructed which can be used to invert the shape of knots in the board.The experiment was conducted on ten defective larch boards,and the experimental results showed that this method can accurately invert the shapes of defects in solid wood boards with the advantages of low cost and easy operation. 展开更多
关键词 Timber knot inversion Distance regularized level set segmentation(DRLSE) Ellipse fi tting K-medoids cluster
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Study on Volume Strain Inversion from Water Level Change of Well-aquifer Systems
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作者 Yan Rui Gao Fuwang Chen Yong 《Earthquake Research in China》 2008年第1期82-88,共7页
Based on linear poroelasfic and hydrogeology theory, a mathenmatical expression describing the relationship between water level clmnge and aquifer volume strain is put forward. Combined with earth tidal theory, we ana... Based on linear poroelasfic and hydrogeology theory, a mathenmatical expression describing the relationship between water level clmnge and aquifer volume strain is put forward. Combined with earth tidal theory, we analyze the response characteristics from well-aquifer water level change to earth tide of volume strain and present a method of volume strain inversion from water level clmnge. Comparing the results of inversion with real observed data, we found that there is a good consistency. This suggests that the method of volume strain inversion from water level clmnge is proper. It will offer a reference for learning about hydrogeology characteristics, volume strain and searching for precursor anomalies. 展开更多
关键词 Well-aquifer system Water level tide Volume strain inversion
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Fabrication of multi-level 3-dimension microstructures by phase inversion process
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作者 Y.Song 《Nano-Micro Letters》 SCIE EI CAS 2010年第2期95-100,共6页
One process based on phase inversion of fillers in microstructures for the fabrication of multi-level three-dimensional(3-D) microstructures is described using SU-8, a kind of epoxy photoresist, as the model construct... One process based on phase inversion of fillers in microstructures for the fabrication of multi-level three-dimensional(3-D) microstructures is described using SU-8, a kind of epoxy photoresist, as the model constructing materials. This process is depicted by use of the routine photolithography technique to construct the top layer of 3-D microstructures on the bottom layer of 3-D microstructures layer by layer. This process makes it possible to fabricate multi-level 3-D microstructures with connectors at desired locations, and to seal long span microstructures(e.g. very shallow channels with depth less than 50 μm and width more than 300 μm) without blockage. In addition, this process can provide a sealing layer by the solidification of a liquid polymer layer, which can be as strong as the bulk constructing materials for microstructures due to a complete contact and cross-linking between the sealing layer and the patterned layers. The hydrodynamic testing indicates that this kind of sealing and interconnection can endure a static pressure of more than 10 MPa overnight and a hydrodynamic pressure drop of about 5.3 MPa for more than 8 hours by pumping the tetrahydrofuran solution through a 60 μm wide micro-channels. 展开更多
关键词 MICROSTRUCTURES MULTI-level FABRICATION PHOTOLITHOGRAPHY Phase inversion SEALING
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Lasing without inversion in a four-level diamond system
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作者 高强 宋同强 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期243-249,共7页
We study the lasing without inversion in a four-level diamond configuration in the case of incoherent pumping field within the framework of the bare-state basis. With the strong fields limit, we obtain the approximate... We study the lasing without inversion in a four-level diamond configuration in the case of incoherent pumping field within the framework of the bare-state basis. With the strong fields limit, we obtain the approximate steady-state solution, and discuss the dependence of population distribution and system gain on probe detuning and auxiliary field Rabi frequency. 展开更多
关键词 lasing without inversion four-level diamond system cyclic transition
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the phase-dependent gain without inversion in a Doppler broadened open four-level system
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作者 刘中波 贾克宁 +2 位作者 梁颖 仝殿民 樊锡君 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期227-233,共7页
It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase ... It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case. 展开更多
关键词 open N-type four-level system spontaneously generated coherence relative phase Doppler broadening gain without inversion
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Modulation of atomic exit and injection rates on the phase-dependent gain without inversion in a Doppler broadened open four-level system
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作者 刘中波 贾克宁 +2 位作者 梁颖 仝殿民 樊锡君 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期231-237,共1页
It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase betw... It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case. 展开更多
关键词 open N-type four-level system spontaneously generated coherence relative phase Doppler broadening gain without inversion
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Potential Vorticity Structure and Inversion of the Cyclogenesis Over the Yangtze River and Huaihe River Valleys 被引量:4
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作者 赵兵科 吴国雄 姚秀萍 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第1期44-54,共11页
In this paper, the potential vorticity structure and inversion of the cyclogenesis over the Yangtze River and Huaihe River valleys during 21 23 June 2003 are investigated with a potential vorticity (PV) framework. T... In this paper, the potential vorticity structure and inversion of the cyclogenesis over the Yangtze River and Huaihe River valleys during 21 23 June 2003 are investigated with a potential vorticity (PV) framework. The cyclogenesis is manifested by a lower-tropospheric PV anomaly over the Yangtze River and Huaihe River valleys at early stages mainly due to latent heat release, which greatly affects the evolution of the associated lower-tropospheric geopotential height and wind fields as demonstrated by piecewise PV inversion. At later stages, an upper-tropospheric PV anomaly develops, resulting in the growth of ridges over the cyclone in both the upstream and downstream, which provide a favorable background field for the low-level cyclone development. But the effect of a surface thermal anomaly always impedes the development of the cyclone to different extents during this cyclogenesis. It is further demonstrated that the position and the strength of the PV anomaly are closely related to the low-level cyclone development, and the lower-tropospheric PV anomaly seems to constitute the most significant feature, for instance, contributing about 60% to the low-level jet (LLJ). 展开更多
关键词 potential vorticity anomaly potential vorticity inversion latent heat release low-level jet cyclogenesis
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Deformation datum in source mechanism inversion
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作者 巩守文 王庆良 +1 位作者 祝意青 陈兵 《Acta Seismologica Sinica(English Edition)》 CSCD 1996年第2期299-308,共10页
Based on the analyses of geodetic deformation datum, the concepts of real datum and relative datum of displacements associated with an earthquake are put foward. Introducting a deformation datum parameter into model p... Based on the analyses of geodetic deformation datum, the concepts of real datum and relative datum of displacements associated with an earthquake are put foward. Introducting a deformation datum parameter into model parameter vector can enable the reference station to be set in the epicentral areas. Two improved inversionmethods, the deformation datum parameter (DDP) method and deformation difference (DD) method, are advanced in this paper. They are further applied to dislocation model inversion of the 1990 Gonghe Ms7.0 earthquake. The inversion results inferred by using the two methods are well consistent with each other, which basically reflect the source geometry and the slip of the causative fault. 展开更多
关键词 deformation datum focal mechanism inversion levelling survey route Gonghe earthquake.
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Undersea Buried Pipeline Reconstruction Based on the Level Set and Inverse Multiquadric Regularization Method
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作者 SHANG Wenjing XUE Wei +2 位作者 XU Yidong MAKAROV Sergey B LI Yingsong 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第1期101-112,共12页
The electric inversion technique reconstructs the subsurface medium distribution from acquired data.On the basis of electric inversion,objects buried under the earth or seabed,such as pipelines and unexploded ordnance... The electric inversion technique reconstructs the subsurface medium distribution from acquired data.On the basis of electric inversion,objects buried under the earth or seabed,such as pipelines and unexploded ordnance,are detected and located in a contactless manner.However,the process of accurately reconstructing the shape of the target object is challenging because electric inversion is a nonlinear and ill-posed problem.In this work,we present an inverse multiquadric(IMQ)regularization method based on the level set function for reconstructing buried pipelines.In the case of locating underwater objects,the unknown inversion area is split into two parts,the background and the pipeline with known conductivity.The geometry of the pipeline is represented based on the level set function for achieving a noiseless inversion image.To obtain a binary image,the IMQ is used as the regularization term,which‘pushes’the level set function away from 0.We also provide an appropriate method to select the bandwidth and regularization parameters for the IMQ regularization term,resulting in reconstructed images with sharp edges.The simulation results and analysis show that the proposed method performs better than classical inversion methods. 展开更多
关键词 inverse problems level set function inverse multiquadric regularization method buried pipeline
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Comparison between effects of Doppler broadening on pure and non-pure inversionless gain with frequency up-conversion
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作者 樊锡君 马慧 +1 位作者 刘中波 仝殿民 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第12期5342-5349,共8页
A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one... A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one-photon inversion does not occur but two-photon inversion is present, in a closed A-type three-level system with incoherent pumping. It is shown that when the driving field is resonant but the probe field is not, in a certain range of Doppler width, for the case of the lower degree of frequency up-conversion, generally, pure gain without inversion increases monotonically and non-pure gain without inversion does not monotonically increase or decrease with increasing Doppler width; for the case of the higher degree of frequency up-conversion, pure gain without inversion decreases monotonically but non-pure gain without inversion cannot be produced. In the case of two-photon resonance, in some range of Doppler width, pure gain without inversion does not monotonically increase or decrease while non-pure gain without inversion decreases monotonically with Doppler width increasing. Finally, an experimental scheme for examining our theoretical result is given. 展开更多
关键词 A-type three-level system Doppler broadening gain without inversion frequency upconversion
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Using WGM2012 to Compute Gravity Anomaly Corrections of Leveling Observations in China
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作者 Yanhui CAI Li ZHANG Xu MA 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第1期88-94,共7页
Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Grav... Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Gravity Anomaly(BGA)map of WGM2012,the feasibility of replacing in-situ gravity surveying in China is investigated.For leveling application,that is to evaluate the accuracy of WGM2012 in China.Because WGM2012 is organized with a standard rectangle grid,two interpolation methods,bilinear interpolating and Inverse Distance Weighted(IDW)interpolating,are proposed.Four sample areas in China,i.e.,Hanzhong,Chengdu,Linzhi and Shantou,are selected to evaluate the systems bias and precision of WGM2012.Numerical results show the average system bias of WGM2012 BGA in west China is about-100.1 mGal(1 mGal=10^(-5) m/s^(2))and the standard deviation is about 30.7 mGal.Tests in Shantou indicate the system bias in plain areas is about-130.4 mGal and standard deviation is about 6.8 mGal.All these experiments means the accuracy of WGM2012 is limited in high mountain areas of western China,but in plain areas,such as Shantou,WGM2012 BGA map is quite good for most leveling applications after calibrating the system bias. 展开更多
关键词 Bouguer Gravity Anomaly(BGA) Gravity Anomaly Correction(GAC) precise leveling WGM2012 bilinear Interpolation inverse Distance Weighted(IDW)interpolation
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降雨和库水位变动联合作用下滑坡位移加权反分析及监测预警方法
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作者 袁维 籍晓蕾 +9 位作者 王东坡 管凯歌 裴子豪 钟辉亚 唐佳 孙瑞峰 王伟 郑贺民 郭帅杰 李红旭 《测绘学报》 EI CSCD 北大核心 2024年第5期917-932,共16页
降雨和库水位变动是诱发大型库岸滑坡体持续变形甚至失稳的主要外在因素。针对以上两种因素联合作用下滑坡体的变形特征,本文提出一种基于多源数据的“反演-评估-融合-预警”四步式滑坡监测预警方法。该方法采用趋势项位移进行力学参数... 降雨和库水位变动是诱发大型库岸滑坡体持续变形甚至失稳的主要外在因素。针对以上两种因素联合作用下滑坡体的变形特征,本文提出一种基于多源数据的“反演-评估-融合-预警”四步式滑坡监测预警方法。该方法采用趋势项位移进行力学参数反演,有效避免了降雨、库水位变动等外在因素对反演结果的影响。同时,采用熵权值构建了反演目标函数,借此考虑了不同位置监测点对反演结果的影响程度。此外,考虑了滑坡体自身的地质条件和坡体结构对监测预警的影响,综合运用安全系数和综合变形速率构建了具有地质和力学基础的预警模型。采用本文方法对贵州三板溪水电站东岭信滑坡体进行了力学参数反演和监测预警,结果表明:该滑坡体整个监测期间的安全系数在1.25~1.70之间波动,整体状态呈下降趋势,基于安全系数的角度判断其尚处于稳定状态;综合变形速率呈现上、下波动趋势,与安全系数在变化规律上具有高度的相关性,两者可以从整体上表征该滑坡体在降雨和库水位变动联合作用下稳定性的演进过程;当前监测时刻点的综合变形速率是0.0599,根据分级预警模型判断此滑坡体当前处于稳定变形阶段(Ⅰ级预警),与安全系数的判断结果具有一致性。 展开更多
关键词 滑坡体 监测预警 参数反演 降雨 库水位变动
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上海市高程基准近五年变化分析
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作者 赵鹏飞 赵峰 《地理空间信息》 2024年第4期117-120,共4页
高程基准是一个地区经济社会发展的重要基础设施。上海市于2020—2022年开展了全市高程基准更新工作。通过对原有高程基准基础设施调查、高程控制网水准复测、高程基准分析三步工作完成了上海市的高程基准的更新并发布新一期的高程基准... 高程基准是一个地区经济社会发展的重要基础设施。上海市于2020—2022年开展了全市高程基准更新工作。通过对原有高程基准基础设施调查、高程控制网水准复测、高程基准分析三步工作完成了上海市的高程基准的更新并发布新一期的高程基准成果。为了掌握上海市高程基准在近5 a的变化情况,对上海市城市水准点的数量变化、区域分布及高程变化情况3个方面进行研究分析,得出了关于上海市城市水准点数量、分布及高程变化的有益结论。最后对上海市高程基准的维护更新提出了一些建议。 展开更多
关键词 高程基准 水准复测 地表沉降 反距离权重法插值 INSAR
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基于改进麻雀搜索算法的水质模型多参数反演
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作者 彭杨 杨德铭 +1 位作者 罗诗琦 张志鸿 《中国农村水利水电》 北大核心 2024年第7期102-109,116,共9页
水质模型参数取值对模型的模拟精度影响很大,为提高BOD-DO水质模型参数反演精度,首先在DobbinsCamp BOD-DO水质模型的基础上,以BOD和DO浓度计算值与实测值之差的加权平方和最小为目标函数,构建了Dobbins-Camp BOD-DO水质多参数反演模型... 水质模型参数取值对模型的模拟精度影响很大,为提高BOD-DO水质模型参数反演精度,首先在DobbinsCamp BOD-DO水质模型的基础上,以BOD和DO浓度计算值与实测值之差的加权平方和最小为目标函数,构建了Dobbins-Camp BOD-DO水质多参数反演模型;然后针对麻雀搜索算法(Sparrow Search Algorithm,SSA)求解精度低、稳定性不足和易陷入局部最优等问题,引入Sine混沌映射和对立学习、转移概率以及差分变异3个策略,分别从提高初始种群多样性、扩大搜索空间以及增强种群跳出局部最优的能力三方面对SSA算法进行改进,提出了一种多策略改进的麻雀搜索算法(Multi-strategy Improved Sparrow Search Algorithm,MISSA),并将其应用于Dobbins-Camp BOD-DO水质多参数反演模型的求解;最后通过数值实验将得到的反演结果与SSA算法、模拟退火算法、粒子群算法、遗传算法四种优化算法进行对比,并探讨了参数初值选取和观测噪声水平对反演结果的影响。结果表明:MISSA算法的计算性能明显优于对照组中的4种算法,且能显著降低初值选取对BOD-DO水质模型参数反演结果的影响,当观测数据的噪声水平不超过5%时,MISSA算法可有效提高反演结果的稳定性。该结果验证了MISSA算法在反演Dobbins-Camp BOD-DO水质模型参数的有效性,为水质模型参数求解提供有益参考。 展开更多
关键词 BOD-DO水质模型 参数反演 多策略改进的麻雀搜索算法 初值选取 观测噪声水平
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GNSS-IR测量水位的精度评估和站点对比:以中国南海北部和日本南部站点为例
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作者 叶脉 李琳琳 +2 位作者 彭冬菊 王培涛 邱强 《海洋预报》 CSCD 北大核心 2024年第1期61-73,共13页
通过南海北部和日本多个实例,量化分析影响近岸全球卫星导航系统干涉反射计(GNSS-IR)反演潮位或风暴潮过程效果的主要影响因素。结果表明:接收机所能接收的卫星信号波段数量、反射信号功率对反演的时间分辨率和精度影响巨大。研究以中... 通过南海北部和日本多个实例,量化分析影响近岸全球卫星导航系统干涉反射计(GNSS-IR)反演潮位或风暴潮过程效果的主要影响因素。结果表明:接收机所能接收的卫星信号波段数量、反射信号功率对反演的时间分辨率和精度影响巨大。研究以中国香港HKQT站点为例量化多模多频GNSS-IR监测风暴潮的优势,同时展示日本J425站点在潮位站空缺地区记录完整风暴潮波形的能力。分别针对卫星信号接受波段、硬件配置、台站架设位置和架设高度等因素,对未来架设具有测量海平面能力的近岸GNSS站点提供具体的指导意见。 展开更多
关键词 GNSS-IR 长期水位 风暴潮 反演影响因素
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王庆坨水库周边地下水位反演与浸没评价
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作者 冯伟骞 杨慧 刘小川 《海河水利》 2024年第6期56-63,共8页
根据地下水位监测资料,对王庆坨水库蓄水前围坝及库区地下水位的基本情况进行详细梳理,分析水库库区内地下水动态变化特征,获得了蓄水前后地下水位分布规律。在此基础上,依据王庆坨水库建设中使用的渗流控制方案,构建王庆坨水库围坝及... 根据地下水位监测资料,对王庆坨水库蓄水前围坝及库区地下水位的基本情况进行详细梳理,分析水库库区内地下水动态变化特征,获得了蓄水前后地下水位分布规律。在此基础上,依据王庆坨水库建设中使用的渗流控制方案,构建王庆坨水库围坝及库区三维渗流有限元模型,进行了大量的反演分析,对王庆坨水库蓄水后的浸没情况进行客观分析与评价,以确定水库蓄水后对周边的影响。 展开更多
关键词 王庆坨水库 地下水位 监测 三维渗流 有限元 反演分析 浸没评价
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一种太阳翼对接用调姿机构虚腿调平策略
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作者 商涛 鲍成文 +2 位作者 寇士营 王文宗 石震宇 《航天控制》 CSCD 2024年第4期78-84,共7页
针对太阳翼对接过程中姿态调整的快速性和准确性需求及人工调整不便的问题,本文设计了一种调平策略,能够根据地面状态更新调姿机构的运动学参数,利用激光跟踪仪获取调平所需位姿,采用基于运动学逆解的关节位置闭环控制实现动平台的调平... 针对太阳翼对接过程中姿态调整的快速性和准确性需求及人工调整不便的问题,本文设计了一种调平策略,能够根据地面状态更新调姿机构的运动学参数,利用激光跟踪仪获取调平所需位姿,采用基于运动学逆解的关节位置闭环控制实现动平台的调平,避免了传统支腿升降调平法在调平过程中存在的虚腿问题,实现了调姿机构从支腿收起状态到触地支撑状态再到动平台调至水平状态的自动调节。通过仿真验证了该调平策略的可行性,为太阳翼对接用调姿机构在工程应用中存在的虚腿调平问题提供了解决思路和方法。 展开更多
关键词 并联机构 虚腿调平 运动学逆解 激光跟踪仪
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一种GNSS-MR海平面高度反演模型研究
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作者 张卫平 刘立龙 +3 位作者 陈发德 张志 郑明明 吴昊舰 《无线电工程》 2024年第2期369-377,共9页
针对大地测量型GNSS接收机获取的信噪比(Signal to Noise Ratio,SNR)观测值存在趋势项分离不佳和信号叠加干涉的问题,融合自适应噪声完备集合鲁棒局部均值分解方法对原始SNR信号进行分解,有效分离SNR观测值中的趋势项并提取相应的潮位信... 针对大地测量型GNSS接收机获取的信噪比(Signal to Noise Ratio,SNR)观测值存在趋势项分离不佳和信号叠加干涉的问题,融合自适应噪声完备集合鲁棒局部均值分解方法对原始SNR信号进行分解,有效分离SNR观测值中的趋势项并提取相应的潮位信号,以布设在美国华盛顿州星期五海港岸边的SC02测站为例,利用实测数据反演潮位变化并与传统的低阶多项式拟合方法进行对比分析。结果表明,融合CERLMDAN方法的反演结果的均方根误差(Root Mean Square Error,RMSE)、相关系数分别为0.56 m和0.97,相比于传统方法的反演精度提升了33.7%。 展开更多
关键词 全球导航卫星系统多路径反射 自适应噪声完备集合鲁棒局部均值分解 潮位反演 信噪比
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基于改进遗传算法的胶结砂砾石料细观层面参数反演分析
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作者 管子 李玲 《安徽水利水电职业技术学院学报》 2024年第1期29-33,共5页
针对传统室内试验无法获取胶结砂砾石料细观层面参数的问题,提出基于改进遗传算法的胶结砂砾石料细观层面参数反演分析方法。以胶结砂砾石料室内单轴压缩试验结果为反演目标值,通过有限元软件模拟建立室内试验的胶结砂砾石试件随机骨料... 针对传统室内试验无法获取胶结砂砾石料细观层面参数的问题,提出基于改进遗传算法的胶结砂砾石料细观层面参数反演分析方法。以胶结砂砾石料室内单轴压缩试验结果为反演目标值,通过有限元软件模拟建立室内试验的胶结砂砾石试件随机骨料模型,反演分析确定胶结砂砾石细观组分参数,解决了室内试验无法获取参数的问题。研究结果表明:在该试验条件下,通过反演分析确定的细观组分参数进行室内试验数值模拟结果与试验值基本一致,胶结砂砾石料的骨料弹性模量EG最终值为550 MPa,砂浆基质弹性模量Em最终值为40MPa,界面弹性模量Ei最终值为30MPa。 展开更多
关键词 胶结砂砾石料 细观层面 单轴压缩 改进遗传算法 反演分析
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