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岩体裂隙网络非线性非立方渗流研究与应用 被引量:3
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作者 徐维生 柴军瑞 +1 位作者 陈兴周 孙旭曙 《岩土力学》 EI CAS CSCD 北大核心 2009年第S1期53-57,共5页
裂隙岩体渗流与岩体其他分析密切相关。岩体裂隙网络渗流理论最初主要是建立在线性立方定律的基础基上的,当裂隙水头较大或者流速较大时,裂隙水流不再满足线性立方定律,此时如仍用线性立方水流分析,无疑将会给渗流分析带来较大的误差,... 裂隙岩体渗流与岩体其他分析密切相关。岩体裂隙网络渗流理论最初主要是建立在线性立方定律的基础基上的,当裂隙水头较大或者流速较大时,裂隙水流不再满足线性立方定律,此时如仍用线性立方水流分析,无疑将会给渗流分析带来较大的误差,甚至引起工程事故。当裂隙水流不满足线性立方定律时,研究这种渗流自身的规律则是非常重要的,也是必要的。通过研究裂隙网络稳定和非稳定情况下的非线性渗流、非立方渗流规律,得出以下结论:①当渗流规律偏离线性渗流较远时,按非线性渗流计算出的水头分布和流量与线性渗流相差较大;当偏离不远时,计算出的水头分布和流量与线性渗流相差较小,可近似简化为线性渗流分析;②当渗流偏离立方渗流较远时,按非立方渗流计算出的水头分布和流量与立方渗流相差较大;当偏离不远时,计算出的水头分布和流量与立方渗流相差较小,可近似简化为立方渗流分析;③对于非线性非立方渗流,应综合考虑非线性与非立方两种因素对渗流的影响。 展开更多
关键词 裂隙网络岩体 线性 非立方 稳定 渗流
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非立方晶系电子衍射花样的ξ表法 被引量:1
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作者 杨国涛 杨进 《理化检验(物理分册)》 CAS 2003年第11期568-570,共3页
提出了一种不使用仪器常数Lλ可鉴定非立方晶系电子衍射花样(EDP)选区物相及确定其指数{hkl}的新方法———相对d值表法(简称ξ表法)。由于省去了繁琐的Lλ测定,在一般情况下,ξ表法较传统的d值表法[1]简便,精度也得到了提高。
关键词 非立方晶系 电子衍射花 晶面间距 物相鉴定 晶面指数 晶格常数 测量相对误差
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最小二乘法在精确测定非立方晶系中的应用 被引量:1
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作者 胡正西 《广西科学院学报》 2004年第1期20-21,25,共3页
利用最小二乘法消除误差 ,导出正交晶系的法式方程 ,由此推导出非立方晶系的基本形式 ,并以六方晶系为例 ,给出方程组的求解过程 .
关键词 最小二乘法 精确测定 非立方晶系 点阵常数 法式方程 晶体材料
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一个非立方晶系晶体的X-射线粉末图的指标化方法
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作者 郭利中 刘光宇 《纺织基础科学学报》 CAS 1994年第1期51-53,16,共4页
本文提出了一种关于非立方晶系晶体的X-射线粉末图的指标化方法,它利用由单晶测得的晶胞参数,通过我们导出的晶胞参数和衍射指标的关系,结合实验数据,便可对非立方晶系的X-射线粉末图指标化。
关键词 非立方晶系 晶体 X射线 粉末图
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解复立方非谐振子的变分矩阵近似法
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作者 龚仁山 《南昌大学学报(理科版)》 CAS 北大核心 2006年第5期455-458,共4页
提出了一种可借助于最小敏感性原理求解本征能量的双变分参数的近似方法。阐明了将这种近似方法应用于复立方非谐振子的有效性,给出了决定两变分参数的方程组以及计算复立方非谐振子系统的哈密顿量的矩阵元的完整计算公式。分析表明,通... 提出了一种可借助于最小敏感性原理求解本征能量的双变分参数的近似方法。阐明了将这种近似方法应用于复立方非谐振子的有效性,给出了决定两变分参数的方程组以及计算复立方非谐振子系统的哈密顿量的矩阵元的完整计算公式。分析表明,通过数值计算可得到该系统哈密顿量的所有本征值的近似值。 展开更多
关键词 立方谐振子 变分矩阵近似法 最小敏感性原理
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移动立方体算法的研究和改进 被引量:15
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作者 钱峰 马秀丽 +1 位作者 杨胜齐 万旺根 《计算机工程与应用》 CSCD 北大核心 2010年第34期177-180,共4页
CT三维重建技术是辅助医生对病情进行分析和显示的有效工具,它极大地提高了医疗诊断的准确性。移动立方体法(Marching Cubes,MC)是一种经典的医学图像三维重建算法,但是在实际使用中还是存在着一些缺点。针对传统MC算法出现的两个问题:... CT三维重建技术是辅助医生对病情进行分析和显示的有效工具,它极大地提高了医疗诊断的准确性。移动立方体法(Marching Cubes,MC)是一种经典的医学图像三维重建算法,但是在实际使用中还是存在着一些缺点。针对传统MC算法出现的两个问题:(1)用直线代替双曲线来构造等值面会产生误差;(2)重建过程中大量时间耗费在检查空立方体上,提出了一种改进的MC算法,分别通过切片图像间的插值和基于分割的快速查找法来对此进行解决。通过实验表明,改进的MC算法比起传统MC算法,在三维重建的效果和效率上都得到了很大的提高。 展开更多
关键词 三维重建 移动立方 插值 立方
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岩体粗糙裂隙渗流研究 被引量:5
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作者 徐维生 陈兴周 李娟娟 《西安理工大学学报》 CAS 北大核心 2010年第2期218-222,共5页
渗流线性立方定律是建立在单直平滑裂隙基础上的,而工程中裂隙多是粗糙的,很多裂隙渗流不满足线性立方定律。针对这一问题,根据裂隙分布统计特征生成粗糙裂隙,推导了不同渗流本构关系下的单宽流量公式、裂隙等分段结点水头公式和等效隙... 渗流线性立方定律是建立在单直平滑裂隙基础上的,而工程中裂隙多是粗糙的,很多裂隙渗流不满足线性立方定律。针对这一问题,根据裂隙分布统计特征生成粗糙裂隙,推导了不同渗流本构关系下的单宽流量公式、裂隙等分段结点水头公式和等效隙宽公式。对比分析光滑、粗糙裂隙的渗流规律得出如下结论:①实际工程中的裂隙往往是不平滑的,统计裂隙开度分布规律、研究裂隙开度的模拟是非常有必要的;②粗糙裂隙非立方、非线性型渗流的基本规律与光滑平直裂隙非立方、非线性型渗流的基本规律存在明显不同;③相等平均隙宽条件下的粗糙裂隙比光滑裂隙的过流能力小得多。 展开更多
关键词 立方定律 粗糙裂隙 线性 非立方 渗流
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多级互连网络中的任务分配
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作者 顾沈明 《浙江海洋学院学报(自然科学版)》 CAS 2001年第4期328-330,共3页
讨论了在多级互连网络中的任务分配方法,指出了外部冲突和内部分割是基于多级互连网络系统主要的瓶颈问题;提出了基于BR网络的分配方法,该方法能用于多级互连网络系统中任意立方任务的分配。对于非立方任务的分配,给出了一种基于二分思... 讨论了在多级互连网络中的任务分配方法,指出了外部冲突和内部分割是基于多级互连网络系统主要的瓶颈问题;提出了基于BR网络的分配方法,该方法能用于多级互连网络系统中任意立方任务的分配。对于非立方任务的分配,给出了一种基于二分思想的分配方法。 展开更多
关键词 任务分配 多级互连网络 方立任务 非立方任务
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玻璃晶化法制备氧化物透明陶瓷研究进展 被引量:1
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作者 周春鸣 陈航 +9 位作者 陈旭 李建强 曹月 李延彬 周天元 邵岑 陈士卫 康健 陈浩 张乐 《人工晶体学报》 CAS 北大核心 2023年第9期1555-1569,共15页
透明陶瓷是一种具有广阔应用前景的无机非金属材料,但以粉末烧结为主的传统制备策略存在依赖高质量原料粉体、需要长时间高温处理、设备和工艺复杂、生产成本高等技术限制。玻璃晶化法是通过调控晶化过程实现玻璃全部结晶并且获得透明... 透明陶瓷是一种具有广阔应用前景的无机非金属材料,但以粉末烧结为主的传统制备策略存在依赖高质量原料粉体、需要长时间高温处理、设备和工艺复杂、生产成本高等技术限制。玻璃晶化法是通过调控晶化过程实现玻璃全部结晶并且获得透明陶瓷的新方法,因其可以克服与传统透明陶瓷加工相关的技术困难,并在合成高致密度、无气孔、非立方相、纳米结构透明陶瓷等方面具有独特的优势,而受到人们的广泛关注。本文首先从玻璃晶化法制备氧化物透明陶瓷的工艺方法和组分体系两方面入手,详细概述了该方法的发展历程和研究现状。接着,指出了目前研究中存在的问题,并对其未来发展前景进行了展望,以期该方法能够广泛应用于制备下一代高性能透明陶瓷材料。 展开更多
关键词 玻璃晶化法 玻璃 氧化物透明陶瓷 非立方 纳米结构 组分体系
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Oscillations of the Solutions of Hyperbolic Partial Differential Equations of Neutral Type 被引量:4
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作者 刘安平 曹少琛 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第2期7-13,共7页
In this paper, oscillatory properties of solutions of certain nonlinear hyperbolic partial differential equations are investigated and a series of sufficient conditions for oscillations of the equations are establishe... In this paper, oscillatory properties of solutions of certain nonlinear hyperbolic partial differential equations are investigated and a series of sufficient conditions for oscillations of the equations are established. The results fully indicate that the oscillations are caused by delay. 展开更多
关键词 HYPERBOLIC DELAY OSCILLATION nonlinear NEUTRAL
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Nonlinear Current-Voltage Characteristics and Electroluminescence of cBN Crystal
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作者 窦庆萍 陈占国 +3 位作者 贾刚 马海涛 曹昆 张铁臣 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期609-612,共4页
The current-voltage(I-V) characteristics of cBN crystal sandwiched between two metallic electrodes are measured and found to be nonlinear. Over 20 samples are measured at room temperature with various electrodes, an... The current-voltage(I-V) characteristics of cBN crystal sandwiched between two metallic electrodes are measured and found to be nonlinear. Over 20 samples are measured at room temperature with various electrodes, and the resulting curves are all similar in shape. When a voltage of about 560V is applied to the cBN crystal, the emitted light is visible to the naked eye in a dark room. We explain these phenomena by the space charge limited current and the electronic transition between the X and Г valleys of the conduction band. 展开更多
关键词 n-cBN crystal nonlinear I-V characteristics space charge limited current electronic transition in two valleys
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Asymptotic Behavior and Nonexistence of Positive Solutions of Delay Difference Equations *L
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作者 彭名书 徐千里 《Journal of Beijing Institute of Technology》 EI CAS 1999年第1期25-30,共6页
Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some i... Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included. 展开更多
关键词 OSCILLATION asymptotic behavior positive solution neutral delay difference equation NONLINEARITY
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Spatiotemporal Similaritons in (3+l)-Dimensional Inhomogeneous Nonlinear Medium with Cubic-Quintic Nonlinearity 被引量:3
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作者 陈翼翔 陆璇辉 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期871-877,共7页
We obtain exact spatiotemporal similaritons to a (3+ l)-dimensional inhomogeneous nonlinear Schrodinger equation, which describes the propagation of optical pulses in a cubic-quintic nonlinearity medium with distri... We obtain exact spatiotemporal similaritons to a (3+ l)-dimensional inhomogeneous nonlinear Schrodinger equation, which describes the propagation of optical pulses in a cubic-quintic nonlinearity medium with distributed dispersion and gain. A one-to-one correspondence between such self-similar waves and solutions of the elliptic equation is found when a certain compatibility condition is satisfied. Based on exact solutions, we discuss evolutional behaviors of self-similar cnoidal waves and chirped similaritons in two kind of typicai soliton control systems. Moreover, the comparison between chirped similaritons and chirp-free solitons is given. 展开更多
关键词 spatiotemporal similaritons (3+l)-dimensional cubic-quintic nonlinear SchrSdinger equation dynamical behaviors
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New Generalized Transformation Method and Its Application in Higher-Dimensional Soliton Equation 被引量:2
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作者 BAI Cheng-Lin GUO Zong-Lin ZHAO Hong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期447-451,共5页
A new generalized transformation method is differential equation. As an application of the method, we presented to find more exact solutions of nonlinear partial choose the (3+1)-dimensional breaking soliton equati... A new generalized transformation method is differential equation. As an application of the method, we presented to find more exact solutions of nonlinear partial choose the (3+1)-dimensional breaking soliton equation to illustrate the method. As a result many types of explicit and exact traveling wave solutions, which contain solitary wave solutions, trigonometric function solutions, Jacobian elliptic function solutions, and rational solutions, are obtained. The new method can be extended to other nonlinear partial differential equations in mathematical physics. 展开更多
关键词 new generalized transformation method exact solution (3+1)-dimensional breaking soliton equation KdV equation mKdV equation cubic nonlinear Klein-Gordon equation
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Finite Symmetry Transformation Groups and Some Exact Solutions to(2+1)-Dimensional Cubic Nonlinear Schrdinger Equantion 被引量:3
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作者 LI Biao LI Yu-Qi CHEN Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第5期773-776,共4页
Making use of the direct method proposed by Lou et al. and symbolic computation, finite symmetry transformation groups for a (2+ l)-dimensional cubic nonlinear Schrodinger (NLS) equation and its corresponding cyl... Making use of the direct method proposed by Lou et al. and symbolic computation, finite symmetry transformation groups for a (2+ l)-dimensional cubic nonlinear Schrodinger (NLS) equation and its corresponding cylindrical NLS equations are presented. Nine related linear independent infinitesimal generators can be obtained from the finite symmetry transformation groups by restricting the arbitrary constants in infinitesimal forms. Some exact solutions are derived from a simple travelling wave solution. 展开更多
关键词 symmetry groups cubic NLS equation exact solution
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Oscillation of Second Order Delay Differential Equations with Nonlinear Neutral Term 被引量:2
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作者 XU Zhi-ting JIN Chu-hua 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第2期271-277,共7页
By using the averaging technique, we obtain new oscillation criteria for second order delay differential equation with nonlinear neutral term. These results generalize and improve some known results about neutral dela... By using the averaging technique, we obtain new oscillation criteria for second order delay differential equation with nonlinear neutral term. These results generalize and improve some known results about neutral delay differential equation of second order. 展开更多
关键词 OSCILLATION delay differential equation nonlinear neutral term second order
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Solitary Waves for Cubic-Quintic Nonlinear Schroedinger Equation with Variable Coefficients 被引量:6
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作者 ZHANG Jin-Liang WANG Ming-Liang LI Xiang-Zheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第2期343-346,共4页
The cubic-quintic nonlinear Schroedinger equation (CQNLS) plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic sol... The cubic-quintic nonlinear Schroedinger equation (CQNLS) plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic solitary waves, and trigonometric traveling waves for the cubic-quintic nonlinear Schroedinger equation with variable coefficients (vCQNLS) are derived with the aid of a set of subsidiary high-order ordinary differential equations (sub-equations for short). The method used in this paper might help one to derive the exact solutions for the other high-order nonlinear evolution equations, and shows the new application of the homogeneous balance principle. 展开更多
关键词 cubic-quintic nonlinear Schroedinger equation with variable coefficients homogeneous balance principle solitary wave
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Darboux Transformation for Tzitzeica Equation 被引量:1
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作者 ZHU Jun-Yi GENG Xian-Guo 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4期577-580,共4页
We present a Darboux transformation for Tzitzeica equation associated with 3 × 3 matrix spectral problem.The explicit solution of Tzitzeica equation is obtained,
关键词 Darboux transformation nonlinear evolution equation soliton solutions
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Green's Function Method for Perturbed sine-Gordon Equation 被引量:1
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作者 LIUFeng-Ming CAIHao LIUZheng-You HUANGNian-Ning 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期907-910,共4页
The usual Green's function method is introduced to show the completeness of the squared Jost solutions of the multi-soliton case in this work. Since sine-Gordon equation contains second derivative in time, the kno... The usual Green's function method is introduced to show the completeness of the squared Jost solutions of the multi-soliton case in this work. Since sine-Gordon equation contains second derivative in time, the known procedure with generalized Marchenko equation to show completeness relation of the eigenfunctions of linearized equation is unavailable. And the explicit expressions of Jost solutions are not necessary here. Thus a general method of direct perturbation method for the perturbed sine-Gordon equation is developed. 展开更多
关键词 SOLITONS nonlinear equation PERTURBATION
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A Higher-Dimensional Hirota Condition and Its Judging Method
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作者 GUO Fu-Kui ZHANG Yu-Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第1期27-30,共4页
When a one-dimensional nonlinear evolution equation could be transformed into a bilinear differential form as F(Dt, Dx)f . f = O, Hirota proposed a condition for the above evolution equation to have arbitrary N-soli... When a one-dimensional nonlinear evolution equation could be transformed into a bilinear differential form as F(Dt, Dx)f . f = O, Hirota proposed a condition for the above evolution equation to have arbitrary N-soliton solutions, we call it the 1-dimensional Hirota condition. As far as higher-dimensional nonlinear evolution equations go, a similar condition is established in this paper, also we call it a higher-dimensional Hirota condition, a corresponding judging theory is given. As its applications, a few two-dimensional KdV-type equations possessing arbitrary N-soliton solutions are obtained. 展开更多
关键词 Hirota condition KdV equation soliton solution
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