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Complex Spacetime Frame: Four-Vector Identities and Tensors
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作者 Joseph Akeyo Omolo 《Advances in Pure Mathematics》 2014年第11期567-579,共13页
This paper provides derivation of some basic identities for complex four-component vectors defined in a complex four-dimensional spacetime frame specified by an imaginary temporal axis. The resulting four-vector ident... This paper provides derivation of some basic identities for complex four-component vectors defined in a complex four-dimensional spacetime frame specified by an imaginary temporal axis. The resulting four-vector identities take exactly the same forms of the standard vector identities established in the familiar three-dimensional space, thereby confirming the consistency of the definition of the complex four-vectors and their mathematical operations in the general complex spacetime frame. Contravariant and covariant forms have been defined, providing appropriate definitions of complex tensors, which point to the possibility of reformulating differential geometry within a spacetime frame. 展开更多
关键词 complex Spacetime FRAME Four-Vector IDENTITIES Contravariant and COVARIANT Forms complex tensors
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NUMERICAL SIMULATION OF MORPHOLOGY OF POLYMER CHAIN COILS IN COMPLEX FLOWS 被引量:4
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作者 Hong Zheng Wei Yu Chi-xing Zhou Department of Polymer Materials Science & Engineering,Shanghai Jiaotong University,Shanghai 200240,China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第5期453-462,共10页
A new coupled finite element formulation is proposed to calculate a conformation tensor model in two complex flows: a planar contraction flow and a planar flow around a symmetrically placed cylinder. The components o... A new coupled finite element formulation is proposed to calculate a conformation tensor model in two complex flows: a planar contraction flow and a planar flow around a symmetrically placed cylinder. The components of conformation tensor are first computed together with the velocity and pressure to describe the change of morphology of polymer chain coils in flow fields. Macroscopic quantities of viscoelastic flow are then calculated based on the conformation tensor. Comparisons between the numerical simulations and experiments for stress patterns and velocity profiles are carried out to prove the validity of the method. 展开更多
关键词 Viscoelastic flow MORPHOLOGY complex flows Conformation tensor model Finite element method (FEM).
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Slodkowski Joint Spectrum and Tensor Product
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作者 史平 计国君 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期79-81,共3页
Slodkowski joint spectrum is similar to Taylor joint spectrum, but it has more important meaning in theory and application. In this paper we characterize Slodkowski joint spectrum and generalize some results about ten... Slodkowski joint spectrum is similar to Taylor joint spectrum, but it has more important meaning in theory and application. In this paper we characterize Slodkowski joint spectrum and generalize some results about tensor product. 展开更多
关键词 OPERATORS joint spectrum tensor product Koszul complex
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Tensor-Centric Warfare I: Tensor Lanchester Equations 被引量:1
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作者 Vladimir Ivancevic Peyam Pourbeik Darryn Reid 《Intelligent Control and Automation》 2018年第2期11-29,共19页
We propose the basis for a rigorous approach to modeling combat, specifically under conditions of complexity and uncertainty. The proposed basis is a tensorial generalization of earlier Lanchester-type equations, insp... We propose the basis for a rigorous approach to modeling combat, specifically under conditions of complexity and uncertainty. The proposed basis is a tensorial generalization of earlier Lanchester-type equations, inspired by the contemporary debate in defence and military circles around how to best utilize information and communications systems in military operations, including the distributed C4ISR system (Command, Control, Communications, Computing, Intelligence, Surveillance and Reconnaissance). Despite attracting considerable interest and spawning several efforts to develop sound theoretical frameworks for informing force design decision-making, the development of good frameworks for analytically modeling combat remains anything but decided. Using a simple combat scenario, we first develop a tensor generalization of the Lanchester square law, and then extend it to also include the Lanchester linear law, which represents the effect of suppressive fire. We also add on-off control inputs, and discuss the results of a simple simulation of the final model using our small scenario. 展开更多
关键词 tensor Modeling of complex Warfighting Lanchester-Type COMBAT EQUATIONS C4ISR MILITARY System
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Commuting Structure Jacobi Operator for Real Hypersurfaces in Complex Space Forms
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作者 U-Hang Ki Hiroyuki Kurihara 《Advances in Pure Mathematics》 2013年第2期264-276,共13页
Let M be a real hypersurface of a complex space form with almost contact metric structure (φ,ξ,η,g). In this paper, we prove that if the structure Jacobi operator Rξ=(·,ξ) ξ is φ▽ξξ-parallel and Rξ com... Let M be a real hypersurface of a complex space form with almost contact metric structure (φ,ξ,η,g). In this paper, we prove that if the structure Jacobi operator Rξ=(·,ξ) ξ is φ▽ξξ-parallel and Rξ commute with the shape operator, then M is a Hopf hypersurface. Further, if Rξ is φ▽ξξ-parallel and Rξ commute with the Ricci tensor, then M is also a Hopf hypersurface provided that TrRξ is constant. 展开更多
关键词 complex Space Form Hopf HYPERSURFACE STRUCTURE JACOBI OPERATOR Shape OPERATOR RICCI tensor
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Research on infrared dim and small target detection algorithm based on low-rank tensor recovery
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作者 LIU Chuntong WANG Hao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第4期861-872,共12页
In order to rapidly and accurately detect infrared small and dim targets in the infrared image of complex scene collected by virtual prototyping of space-based downward-looking multiband detection,an improved detectio... In order to rapidly and accurately detect infrared small and dim targets in the infrared image of complex scene collected by virtual prototyping of space-based downward-looking multiband detection,an improved detection algorithm of infrared small and dim target is proposed in this paper.Firstly,the original infrared images are changed into a new infrared patch tensor mode through data reconstruction.Then,the infrared small and dim target detection problems are converted to low-rank tensor recovery problems based on tensor nuclear norm in accordance with patch tensor characteristics,and inverse variance weighted entropy is defined for self-adaptive adjustment of sparseness.Finally,the low-rank tensor recovery problem with noise is solved by alternating the direction method to obtain the sparse target image,and the final small target is worked out by a simple partitioning algorithm.The test results in various spacebased downward-looking complex scenes show that such method can restrain complex background well by virtue of rapid arithmetic speed with high detection probability and low false alarm rate.It is a kind of infrared small and dim target detection method with good performance. 展开更多
关键词 complex scene infrared block tensor tensor kernel norm low-rank tensor restoration weighted inverse entropy alternating direction method
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An Alternative Way to Mapping Cone: The Algebraic Topology of the Pinched Tensor
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作者 Yousuf Alkhezi 《Applied Mathematics》 2023年第11期719-727,共9页
In this research, we explore the properties and applications of the mapping cone and its variant, the pinched mapping cone. The mapping cone is a construction that arises naturally in algebraic topology and is used to... In this research, we explore the properties and applications of the mapping cone and its variant, the pinched mapping cone. The mapping cone is a construction that arises naturally in algebraic topology and is used to study the homotopy type of spaces. It has several key properties, including its homotopy equivalence to the cofiber of a continuous map, and its ability to compute homotopy groups using the long exact sequence associated with the cofiber. We also provide an overview of the properties and applications of the mapping cone and the pinched mapping cone in algebraic topology. This work highlights the importance of these constructions in the study of homotopy theory and the calculation of homotopy groups. The study also points to the potential for further research in this area which includes the study of higher homotopy groups and the applications of these constructions to other areas of mathematics. 展开更多
关键词 complex tensor Product Pinched tensor Product Mapping Cone MORPHISM
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Study of Complex TOUGMA’s Metric
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作者 Jean Luc Wendkouni Tougma 《Open Journal of Applied Sciences》 2023年第7期1005-1011,共7页
General relativity of Einstein’s theory and Quantum physics theory are excellent pillars that explain much modern physics. Understanding the relation between these theories is still a theoretical physics central open... General relativity of Einstein’s theory and Quantum physics theory are excellent pillars that explain much modern physics. Understanding the relation between these theories is still a theoretical physics central open question. Over last several decades, works in this direction have led to new physical ideas and mathematical tools broad range. In recent years TOUGMA’s equation is established and solved, one of its solutions such as a real solution is studied in our last article. In this paper, complex TOUGMA’s metric is studied, particularly the physics concepts that this metric implies such as light geodesic and metric’s impacts at r = 0. The first time, we studied the fact of r = 0 and its limits, secondly, we consider a zero length light geodesic is a geodesic and ended by studying it mathematically. These underlying principles study, those various phenomena in universe are interconnected logic leading to develop new technologies for example: news engines, telecommunication networks. This study’s applications are exceptionally wide such as Astrophysics, cosmology, Quantum gravity, Quantum Mechanics, Multiverse. Mostly this study lets us to know the quantum relativity universe behaviors. 展开更多
关键词 complex Metric of TOUGMA Quantum Relativity Ricci tensor
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Orbits of Material Bodies in Complex TOUGMA’s Metric
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作者 Jean Luc Wendkouni Tougma 《Open Journal of Applied Sciences》 2023年第8期1310-1318,共9页
Einstein’s General relativity theory and Quantum physics are the main pillars for explaining most modern physics. Obtaining these theories relation between them remains a theoretical physics main question. In the las... Einstein’s General relativity theory and Quantum physics are the main pillars for explaining most modern physics. Obtaining these theories relation between them remains a theoretical physics main question. In the last most decades, works are leading to new physical ideas and mathematical tools broad range. In recent years TOUGMA’s equation is established and solved, and one of these solutions, mostly a real solution is studied in our last article. In this work, complex TOUGMA’s metric is studied, such as the physics concepts implied by this metric, mainly material bodies geodesics orbits. We studied the fact material bodies’ orbits and their limits. This study of the underlying principles and various phenomena in universe are interconnected logic leading to new technologies development such as news engines and telecommunication networks. The applications of this study are exceptionally wide such as Astrophysics, cosmology, Quantum gravity, Quantum Mechanics and Multiverse. Mostly this study allows us to know the behaviors of matter in the quantum relativity universe. Universe. 展开更多
关键词 Ricci tensor TOUGMA’s complex Metric Quantum Relativity
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On the Regression-Tensor Analysis of the Hardening Process of Metal Coatings
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作者 Rusanov Vyacheslav Anatolievich Agafonov Sergey Viktorovich +1 位作者 Daneev Aleksey Vasilyevich Gubanov Ilya Alecseevich 《Journal of Applied Mathematics and Physics》 2021年第7期1639-1651,共13页
This paper constructs and studies a nonlinear multivariate regression-tensor model for substantiation of necessary/sufficient conditions of optimization of technological calculation of multifactor physical and chemica... This paper constructs and studies a nonlinear multivariate regression-tensor model for substantiation of necessary/sufficient conditions of optimization of technological calculation of multifactor physical and chemical process of hardening of complex composite media for metal coatings. An adaptive a posteriori procedure for parametric formation of the target quality functional of integrative physical and mechanical properties of the designed metal coating has been proposed. The results of the research may serve as elements of a mathematical language when creating automated design of precision nanotechnologies for surface hardening of complex composite metal coatings on the basis of complex tribological and anticorrosive tests. 展开更多
关键词 Hardening Composite Metal Coatings complex Tribological Tests Optimal Physical and Chemical Process Multivariate Regression-tensor Analysis
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基于水平集的作物病叶图像分割方法 被引量:22
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作者 袁媛 李淼 +2 位作者 梁青 胡秀珍 张伟 《农业工程学报》 EI CAS CSCD 北大核心 2011年第2期208-212,共5页
针对具有复杂背景的作物病叶图像中的叶片提取问题,提出了一种基于先验信息的水平集模型。首先,在LBF模型中引入纹理信息——结构张量,构造新的水平集模型;其次,采用水平集方法表示目标叶片形状,并将先验形状信息以能量泛函的表达形式... 针对具有复杂背景的作物病叶图像中的叶片提取问题,提出了一种基于先验信息的水平集模型。首先,在LBF模型中引入纹理信息——结构张量,构造新的水平集模型;其次,采用水平集方法表示目标叶片形状,并将先验形状信息以能量泛函的表达形式引入到上述新的水平集模型中,得到新的基于先验信息的水平集模型;最后,利用该模型对具有复杂背景的黄瓜病叶图像进行分割。结果表明,该方法能准确地提取具有复杂背景黄瓜病叶图像中的病叶,为后续的病斑提取、识别和诊断奠定前期基础。 展开更多
关键词 图像分割 水平集方法 结构张量 先验形状 复杂背景
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二度体的重力张量有限元正演模拟 被引量:16
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作者 朱自强 曾思红 +1 位作者 鲁光银 严文婕 《物探与化探》 CAS CSCD 北大核心 2010年第5期668-671,685,共5页
介绍了重力梯度张量,并将有限单元法应用于二维重力梯度张量的正演计算。为了验证有限元正演方法的精度,对截面为矩形的两个二度体组合模型进行有限元正演模拟,结果表明正演曲线与理论曲线形态一致,拟合情况好。通过对截面形状不规则、... 介绍了重力梯度张量,并将有限单元法应用于二维重力梯度张量的正演计算。为了验证有限元正演方法的精度,对截面为矩形的两个二度体组合模型进行有限元正演模拟,结果表明正演曲线与理论曲线形态一致,拟合情况好。通过对截面形状不规则、密度分块均匀的二度体进行正演模拟,说明有限元法可通过网格剖分来逼近不规则目标体的边界,并对剖分单元赋予不同的密度值来实现对复杂二度体的重力张量的正演模拟。 展开更多
关键词 复杂二度体 重力张量 有限元 正演模拟
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复杂天空背景下基于GST的红外斑点小目标检测 被引量:6
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作者 高陈强 田金文 +1 位作者 王鹏 刘玮 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2009年第7期10-13,共4页
针对传统的杂波抑制方法的不足,提出了基于推广结构张量的红外斑点小目标检测方法.首先利用一阶高斯对称偏导滤波器计算图像的方向场;然后把斑点小目标看成是圆对称模式,根据推广结构张量检测理论,选择相应的复值滤波器应用到方向场,并... 针对传统的杂波抑制方法的不足,提出了基于推广结构张量的红外斑点小目标检测方法.首先利用一阶高斯对称偏导滤波器计算图像的方向场;然后把斑点小目标看成是圆对称模式,根据推广结构张量检测理论,选择相应的复值滤波器应用到方向场,并计算确定性图像;接着利用信息熵对图像复杂度进行评估,并根据评估结果确定分割阈值;最后对确定性图像进行分割和虚假目标删除,得到检测结果.实验结果表明:该算法能快速有效地检测复杂天空背景下的红外斑点小目标,检测概率达96%以上,明显优于传统方法. 展开更多
关键词 红外斑点小目标检测 复杂背景 对称模式 推广结构张量 信息熵
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磁共振扩散张量成像对正常女性尿道括约肌复合体及肛提肌结构的分析研究 被引量:7
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作者 张静 杨子涛 +3 位作者 赵志恒 吴玥 程敬亮 车英玉 《磁共振成像》 CAS CSCD 北大核心 2022年第4期128-131,共4页
目的利用3.0 T MR扩散张量成像(diffusion tensor imaging,DTI)技术探讨分娩和年龄对正常女性尿道括约肌复合体及肛提肌结构的影响变化,为分析盆底功能障碍的发病机制提供客观依据。材料与方法前瞻性纳入103例无盆底功能障碍的女性志愿... 目的利用3.0 T MR扩散张量成像(diffusion tensor imaging,DTI)技术探讨分娩和年龄对正常女性尿道括约肌复合体及肛提肌结构的影响变化,为分析盆底功能障碍的发病机制提供客观依据。材料与方法前瞻性纳入103例无盆底功能障碍的女性志愿者,根据有无分娩史分为正常对照组24例和经产妇组79例,然后再将经产妇组按年龄段分为≤30岁组(19例)、31~44岁组(22例)、45~59岁组(27例)和≥60岁组(11例)四个亚组。采用二维扩散加权横断自旋梯度回波(spin-echo-gradient-recalled echo,SE-GRE)脉冲序列对所有受试者行盆底DTI检查,测量尿道中段环形括约肌、纵行肌、耻骨直肠肌及髂尾肌肌纤维的DTI参数,包括各向异性分数(fractional anisotropy,FA)、表观扩散系数(apparent diffusion coefficient,ADC)值、三个特征值(λ1,λ2,λ3),分析分娩史及不同年龄对尿道及肛提肌的微观组织结构的影响。结果(1)经产妇组中≤30岁组耻骨直肠肌FA值较正常对照组小,差异有统计学意义(t=2.206,P=0.030);(2)经产妇组中不同年龄组间尿道中段环形括约肌ADC值、λ2值及λ3值之间比较,差异均有统计学意义(F=3.547、4.105、3.596,P=0.018、0.009、0.017),尿道中段纵行肌DTI各参数比较,差异无统计学意义(P>0.05);(3)经产妇组中不同年龄组间耻骨直肠肌FA值、ADC值、λ1值及λ2值之间比较,差异均有统计学意义(F=8.071、6.051、6.672、3.688,P<0.001、P=0.001、P<0.001、P=0.013);(4)经产妇组中不同年龄组间髂尾肌FA值、ADC值及λ3值之间比较,差异均有统计学意义(F=5.676、3.110、5.175,P=0.001、0.028、0.002)。结论分娩史主要影响耻骨直肠肌的微观结构,年龄因素对尿道环形括约肌及肛提肌微观结构的改变有一定的影响,DTI技术对观察盆底肌结构和评估微结构变化具有重要价值。 展开更多
关键词 扩散张量成像 尿道括约肌复合体 肛提肌 年龄 分娩 盆底功能障碍
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高精度结构曲率提取方法在潜江凹陷构造解释中的应用 被引量:5
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作者 霍志周 刘喜武 +2 位作者 莫莉 钟庆良 张颖燕 《石油物探》 EI CSCD 北大核心 2020年第6期961-969,共9页
广泛用于描述地质体几何形态变化的结构曲率属性可通过求取地层视倾角的偏导数获得,因此地层视倾角估计的精度直接影响结构曲率估计的精度。江汉潜江凹陷工区目的层断层发育、高陡构造较多、地震资料信噪比低,常规结构曲率提取方法无法... 广泛用于描述地质体几何形态变化的结构曲率属性可通过求取地层视倾角的偏导数获得,因此地层视倾角估计的精度直接影响结构曲率估计的精度。江汉潜江凹陷工区目的层断层发育、高陡构造较多、地震资料信噪比低,常规结构曲率提取方法无法有效提取目的层的结构曲率并用于断层及高陡构造等复杂构造带的解释。为此,采用了一种高精度结构曲率提取方法来提取研究区实际资料的结构曲率。该方法首先利用三维数据的瞬时相位构建梯度结构张量,并在此基础上估计地层视倾角;然后采用多窗估计技术来提高地层视倾角的估计精度;最后以高精度地层视倾角为基础进行地层结构曲率估计(包含最大正曲率和最大负曲率)。将高精度结构曲率提取方法及商业软件曲率模块用于江汉潜江凹陷的实际资料处理,结果表明:高精度结构曲率提取方法所提取的地层结构曲率在抗噪性以及断层结构等的刻画精度方面明显优于商业软件曲率模块所提取的地层结构曲率,同时对高陡倾角构造及大断层等构造复杂带的刻画精度更高,更有利于构造解释。该方法可应用于其它类似地区。 展开更多
关键词 复地震道分析 梯度结构张量 特征分解 多窗分析 视倾角 结构曲率 潜江凹陷
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复杂目标的X-样条曲面拟合 被引量:7
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作者 高鹰 谢胜利 《系统仿真学报》 EI CAS CSCD 2001年第2期163-164,188,共3页
在X-样条的算法及性质的基础上讨论了张量积X-样条曲面的算法及性质。并给出了张量积X-样条曲面在复杂目标拟合方面的应用。
关键词 X-样条 曲面拟合 NURBS样条 飞行器 航空 航天
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基于双树复数小波降噪的扩散张量估计 被引量:3
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作者 白衡 王世杰 +1 位作者 罗立民 张宗军 《信号处理》 CSCD 北大核心 2007年第3期330-335,共6页
本文引入了一个从扩散加权图像序列中估计扩散张量的新过程。此过程的第一个步骤是对扩散加权图像降噪,降噪的算法基于双树复数小波变换和双变量收缩规则;第二个步骤对降噪后的扩散加权图像使用最小二乘法估计扩散张量。我们在模拟二阶... 本文引入了一个从扩散加权图像序列中估计扩散张量的新过程。此过程的第一个步骤是对扩散加权图像降噪,降噪的算法基于双树复数小波变换和双变量收缩规则;第二个步骤对降噪后的扩散加权图像使用最小二乘法估计扩散张量。我们在模拟二阶张量场和真实DT-MRI数据集上进行了实验,与扩散张量估计后的平滑方法相比,先对扩散加权图像降噪能够得到更加精确的张量场估计。估计的扩散张量场的客观结果及主观评价可以说明,本文提出的估计过程可以很好地改进最终的扩散场的质量。 展开更多
关键词 双树复数小波 双变量收缩 降噪 扩散张量估计
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体积分方程法模拟复电阻率三维体电磁响应 被引量:13
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作者 张辉 李桐林 董瑞霞 《煤田地质与勘探》 CAS CSCD 北大核心 2006年第1期70-74,共5页
利用体积分方程法计算了均匀半空间中复电阻率(激电)效应和电磁效应同时存在时的三维体响应。在计算中,对于需要计算三重积分的张量格林函数电荷项一次部分,应用一种差分近似的方法求解,这种方法在保证计算精度的同时更加便于计算机实现... 利用体积分方程法计算了均匀半空间中复电阻率(激电)效应和电磁效应同时存在时的三维体响应。在计算中,对于需要计算三重积分的张量格林函数电荷项一次部分,应用一种差分近似的方法求解,这种方法在保证计算精度的同时更加便于计算机实现;采用二次剖分的算法解决了计算张量格林函数时的奇异值问题;计算含有贝塞尔函数的积分项时,利用一种结合连分式展开的高斯求积代替常规的快速汉克尔变换方法。验证了计算结果并分析了三维体复电阻率模型(Cole-Cole)参数对正演结果的影响,为三维体复电阻率及其参数反演提供了正演依据。 展开更多
关键词 体积分方程法 三维 复电阻率 电磁响应 张量格林函数
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β-二酮Gd(Ⅲ)配合物EPR谱解析及其零场分裂张量的计算 被引量:3
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作者 卢加春 成义祥 +1 位作者 徐端钧 徐元植 《波谱学杂志》 CAS CSCD 北大核心 1999年第1期59-64,共6页
稀土Gd(Ⅲ)的电子组态为4f7,七个未偶电子之间较强的自旋自旋相互作用,以致于EPR波谱相互重叠呈一条简单的包络线,几乎得不出有用的信息,限制了EPR波谱在这一领域中的应用.本文用自编的一个模拟程序,先是对包络线... 稀土Gd(Ⅲ)的电子组态为4f7,七个未偶电子之间较强的自旋自旋相互作用,以致于EPR波谱相互重叠呈一条简单的包络线,几乎得不出有用的信息,限制了EPR波谱在这一领域中的应用.本文用自编的一个模拟程序,先是对包络线进行分解剥离,确定各谱峰的g值.然后用自编的另一个程序根据所得之g值计算出零场分裂张量D和E.对五个不同的β二酮类Gd(Ⅲ)配合物进行了解析和计算。 展开更多
关键词 稀土Gd(Ⅲ) β-二酮配合物 EPR波谱 零场分裂张量
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0期无症状HIV相关性痴呆脑白质微细结构的DTI研究 被引量:3
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作者 李瑞利 李宏军 +4 位作者 米海峰 赵晶 员达 柳娇娇 齐石 《临床放射学杂志》 CSCD 北大核心 2014年第12期1813-1817,共5页
目的探讨0期无症状HIV相关性痴呆(HAD)常规MRI检查表现正常的脑白质磁共振扩散张量成像(DTI)的改变及其早期诊断价值。方法对32例0期无症状HAD患者和29名与之年龄、性别相匹配的健康志愿者为对照行MRI扫描,获取常规MRI(T1WI、T2WI、T2FL... 目的探讨0期无症状HIV相关性痴呆(HAD)常规MRI检查表现正常的脑白质磁共振扩散张量成像(DTI)的改变及其早期诊断价值。方法对32例0期无症状HAD患者和29名与之年龄、性别相匹配的健康志愿者为对照行MRI扫描,获取常规MRI(T1WI、T2WI、T2FLAIR)及DTI图像,测量其额叶、顶叶、颞叶、枕叶、胼胝体膝部、压部、内囊前、后肢白质区部分各向异性分数(FA)和表观扩散系数(ADC)。利用独立样本t检验比较HIV患者与对照组的FA值及ADC值。进一步根据CD4+计数将患者分为两组,即CD4+<200/mm3组、CD4+>200/mm3组,利用单因素方差分析比较CD4+<200/mm3组、CD4+>200/mm3组的HIV患者及对照组的FA值及ADC值。结果与正常对照组比较,0期无症状HAD患者的额叶、顶叶、颞叶、枕叶、胼胝体膝部、压部、内囊前、后肢白质的FA值均有所降低,但差异无统计学意义(P>0.05);对应ADC值呈不同幅度的增加:额叶、枕叶、内囊前肢白质显著增加(P<0.05),而顶叶、颞叶、胼胝体膝部、压部、内囊后肢白质区域的差异均无统计学意义(P>0.05)。另外,CD4+T细胞数<200/mm3的HIV患者额叶、枕叶白质的ADC值显著高于CD4+T细胞数>200/mm3的HIV患者及正常对照组(P<0.05),而对应FA值的差异均无统计学意义(P>0.05)。结论对无症状期HAD患者行定量DTI分析,有助于评价HAD患者在常规MRI检查表现正常的脑区的微结构改变,进而有助于HAD的早期诊治,阻止或逆转认知下降。定量ADC值的变化表明HAD疾病早期损害优先出现在额叶、枕叶,其结构特点(与高级皮层功能相关的脑区)可能是HAD早期易受损害的重要原因。此外,低CD4+T淋巴细胞计数可能是HIV患者进展为HAD的重要危险因素之一。 展开更多
关键词 扩散张量成像 脑白质 HIV相关性痴呆 0期 无症状
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