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中国大陆M_(S)≥5.0地震序列扩展的B?th定律及主要影响因素讨论
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作者 蒋海昆 《地球物理学报》 北大核心 2025年第5期1826-1841,共16页
基于1970—2022年中国大陆M_(S)≥5.0地震序列资料,研究地震序列震级差ΔM=M0-M1统计特征,M0、M1分别为序列首次M_(S)≥5.0地震及后续最大地震震级.统计样本主要分布在青藏地块及周缘地区、天山地震带以及华北—东北地区.研究结果显示,... 基于1970—2022年中国大陆M_(S)≥5.0地震序列资料,研究地震序列震级差ΔM=M0-M1统计特征,M0、M1分别为序列首次M_(S)≥5.0地震及后续最大地震震级.统计样本主要分布在青藏地块及周缘地区、天山地震带以及华北—东北地区.研究结果显示,中国大陆约99%的M_(S)≥5.0地震序列的ΔM分布于[-1.0,4.4]之间,中位值Q2=1.7,平均值ΔM.ΔM分布符合以1.7为均值、以1.1为标准差的正态分布,与M0无关.ΔM具有一定的区域差异,由小到大依次为青藏地块中西部ΔM≈1.5±1.1、青藏地块东部(以南北地震带为主)ΔM≈1.7±1.1、天山地震带ΔM≈1.8±1.1、华北—东北地区ΔM≈2.1±1.1.其中华北—东北地区ΔM显著偏高,青藏地块中西部ΔM明显偏低,与其他构造区差异显著.对比不同震源机制地震序列的ΔM发现,正断型为主的地震序列ΔM≈1.6±1.0、走滑型为主的地震序列ΔM≈1.7±1.0、逆冲型为主的地震序列ΔM≈1.9±1.0,似乎显示一定的震源机制关联性,但无法通过差异显著性检验.中国大陆ΔM的区域性差异可能与区域平均断层运动速率及区域平均能矩比有关,ΔM与区域平均断层运动速率定性负相关、与平均能矩比定性正相关.不同震源机制ΔM之间的差异,可能与震源机制的区域性特征有关.本文采用全部样本的扩展的Bath定律震级差平均值ΔM(≈1.7±1.1),与仅采用主-余型序列样本的经验Bath定律ΔM(≈1.8±1.0)之间,尽管仅相差0.1个震级单位,但Z检验结果显示二者之间差异显著.无论是扩展的Bath定律还是经验Bath定律,中国大陆M_(S)≥5.0地震序列震级差的平均值ΔM均明显偏高于经验Bath定律ΔM≈1.2的预期,但与近几十年来全球大多数区域平均约1.6的研究结果基本一致. 展开更多
关键词 扩展的Båth定律 地震序列震级差ΔM 震级差平均值 的区域差异 中国大陆
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Variable mass and thermal properties in three-dimensional viscous flow: Application of Darcy law 被引量:4
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作者 Iffat JABEEN Muhammad FAROOQ Nazir A. MIR 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第5期1271-1282,共12页
This article concentrates on the properties of three-dimensional magneto-hydrodynamic flow of a viscous fluid saturated with Darcy porous medium deformed by a nonlinear variable thickened surface.Analysis of flow is d... This article concentrates on the properties of three-dimensional magneto-hydrodynamic flow of a viscous fluid saturated with Darcy porous medium deformed by a nonlinear variable thickened surface.Analysis of flow is disclosed in the neighborhood of stagnation point.Features of heat transport are characterized with Newtonian heating and variable thermal conductivity.Mass transport is carried out with first order chemical reaction and variable mass diffusivity.Resulting governing equations are transformed by implementation of appropriate transformations.Analytical convergent series solutions are computed via homotopic technique.Physical aspects of numerous parameters are discussed through graphical data.Drag force coefficient,Sherwood and Nusselt numbers are illustrated through graphs corresponding to various pertinent parameters.Graphical discussion reveals that conjugate and constructive chemical reaction parameters enhance the temperature and concentration distributions,respectively. 展开更多
关键词 Newtonian heating chemical reaction variable mass diffusivity darcy law
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结合Cannikin’s Law的离线数据增广方法研究
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作者 邓雪 赵皓 +2 位作者 张静 梅菠萍 张华 《计算机工程与应用》 CSCD 北大核心 2023年第1期207-212,共6页
数据增广是提升深度学习模型性能的有效方法之一。针对多类别目标检测任务中检测性能不平衡问题,提出一种针对“短板类别”(检测性能远低于模型平均检测性能的类别)的离线数据增广方法。受Cannikin’s Law的启发,采用基于复制粘贴(copy-... 数据增广是提升深度学习模型性能的有效方法之一。针对多类别目标检测任务中检测性能不平衡问题,提出一种针对“短板类别”(检测性能远低于模型平均检测性能的类别)的离线数据增广方法。受Cannikin’s Law的启发,采用基于复制粘贴(copy-paste)机制的场景多样性增广方法。随机采集训练集中“短板类别”实例区域,通过相似性度量机制选取训练集中增广目标样本进行随机粘贴。为了降低随机粘贴导致的遮挡问题,采用基于自遮挡(cut-replace)机制的增广方法提升模型遮挡表达能力。通过截取样本自身区域,对特征表达最显著区域进行遮挡。实验表明,FCOS目标检测框架在PASCAL VOC数据上的平均检测精度(mean average precision,mAP)从79.10%提升到83.90%,其中短板类别更为显著,提升了20.8个百分点。在MS-COCO数据上平均检测精度提升了0.9个百分点。 展开更多
关键词 数据增广 Cannikin’s law 相似性度量机制 自遮挡 目标检测
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Function S-rough sets and mining-discovery of rough law in systems 被引量:25
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作者 Shi Kaiquan Xia Jiarong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第4期919-926,共8页
Function S-rough sets (function singular rough sets) is defined on a -function equivalence class [u]. Function S-rough sets is the extension form of S-rough sets. By using the function S-rough sets, this paper gives... Function S-rough sets (function singular rough sets) is defined on a -function equivalence class [u]. Function S-rough sets is the extension form of S-rough sets. By using the function S-rough sets, this paper gives rough law generation model of a-function equivalence class, discussion on law mining and law discovery in systems, and application of law mining and law discovery in communication system. Function S-rough sets is a new theory and method in law mining research. 展开更多
关键词 function s-rough sets structure of function s-rough sets relationship theorem rough law mining-discovery applications.
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F-rough law and the discovery of rough law 被引量:12
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作者 Qiu Jinming Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期81-89,共9页
By using function one direction S-rough sets (function one direction singular rough sets), this article presents the concepts of F-law, F-rough law, and the relation metric of rough law; by using these concepts, thi... By using function one direction S-rough sets (function one direction singular rough sets), this article presents the concepts of F-law, F-rough law, and the relation metric of rough law; by using these concepts, this article puts forward the theorem of F-law relation metric, two orders theorem of F-rough law relation metric, the attribute theorem of F-rough law band, the extremum theorem of F-rough law relation metric, the discovery principle of F-rough law and the application of F-rough law. 展开更多
关键词 function one direction s-rough sets F-rough law rough law relation metric the theorem of relationmetric the discovery principle ofF-rough law application.
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耦合Navier-Stokes/Darcy模型多重网格方法的有限元实现(英文)
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作者 沈宇晶 韩丹夫 邵新平 《应用数学》 CSCD 北大核心 2016年第2期457-468,共12页
本文研究耦合Navier-Stokes/Darcy模型问题.构造一种从粗网格到细网格的有限元空间插值方法,不但简化了数值积分的单元匹配,也保证了数值积分的精度.利用基于有限元空间的多重网格方法,获得与直接法求解耦合问题误差相同的收敛阶,推广... 本文研究耦合Navier-Stokes/Darcy模型问题.构造一种从粗网格到细网格的有限元空间插值方法,不但简化了数值积分的单元匹配,也保证了数值积分的精度.利用基于有限元空间的多重网格方法,获得与直接法求解耦合问题误差相同的收敛阶,推广两重网格方法的结果. 展开更多
关键词 不可压缩流 多孔介质流 NAVIER-sTOKEs方程 darcy定律 多重网格方法 MI-NI有限元 Q2-Q1有限元
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Rough law generation and its separation-recognition 被引量:2
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作者 Li Dongya Ren Xuefang Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1239-1246,共8页
By using function S-rough sets(function singular rough sets), this paper gives rough law generation and the theorem of rough law generation.Based on these results above, the paper proposes rough law separation, the ... By using function S-rough sets(function singular rough sets), this paper gives rough law generation and the theorem of rough law generation.Based on these results above, the paper proposes rough law separation, the theorem of rough law separation, the compound generation theorem of rough law bands, and the principle of rough law bands.In the end, an application of rough law separation in recognizing the risk law of profit is presented. 展开更多
关键词 function one-directional s-rough set dual of function one-directional s-rough set rough law law separation the theorem of law separation the principle of rough law band application.
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F-generation law and recognition of system law 被引量:4
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作者 Shi Kaiquan Yao Bingxue 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第4期764-768,共5页
If a system is not disturbed (or invaded) by some law, there is no doubt that each system will move according to the expected law and keep stable. Although such a fact often appears, some unknown law breaks into the... If a system is not disturbed (or invaded) by some law, there is no doubt that each system will move according to the expected law and keep stable. Although such a fact often appears, some unknown law breaks into the system and leads it into turbulence. Using function one direction S-rough sets, this article gives the concept of the F-generation law in the system, the generation model of the F-generation law and the recognition method of the system law. Function one direction singular rough sets is a new theory and method in recognizing the disturbance law existing in the system and recognizing the system law. 展开更多
关键词 function one direction s-rough sets F-generation law recognition of system law recognition criterion APPLICATION
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F-interference law generation and its feature recognition 被引量:5
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作者 Qiu Jinming Zhang Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第4期777-783,共7页
By using two-directional S-rough sets, the concepts of (f, f)-interference generation and (f, f)- interference law generation of knowledge, F-interference generation and F-interference law generation of two-direct... By using two-directional S-rough sets, the concepts of (f, f)-interference generation and (f, f)- interference law generation of knowledge, F-interference generation and F-interference law generation of two-directional S-rough sets are proposed. Based on the concepts above, the relation theoreras between F-interference loss and F-interference degree, the relation theorems between F-interference loss law and F-interference degree law, the dis- cernibility theorems between F-interference and F-interference law are presented. At last, the recognition criterion of F-interference law and its application are given. 展开更多
关键词 two-directional s-rough sets F-interference F-interference law discernibility theorem of F- interference recognition of F-interference law applications.
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F-Law collision and system state recognition 被引量:4
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作者 Shi Kaiquan Xu Xiaojing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第2期259-264,共6页
Using function one direction S-rough sets (function one direction singular rough sets), f-law and F- law and the concept of law distance and the concept of system law collided by F-law are given. Using these concept... Using function one direction S-rough sets (function one direction singular rough sets), f-law and F- law and the concept of law distance and the concept of system law collided by F-law are given. Using these concepts, state characteristic presented by system law collided by F-law and recognition of these states characteristic and recognition criterion and applications are given. Function one direction S-rough sets is one of basic forms of function S-rough sets (function singular rough sets). Function one direction S-rough sets is importance theory and is a method in studying system law collision. 展开更多
关键词 Function one direction s-rough sets F -law COLLIsION Characteristic recognition Recognition criterion Applications.
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Rough law energy and measurement of ■-decomposition rough law 被引量:2
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作者 Shunliang Huang Huafeng Yang Kaiquan Shi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期62-66,共5页
By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ^-f-decomposition law and ^-F-decomposition rough law are proposed, and the measurement of rough law var... By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ^-f-decomposition law and ^-F-decomposition rough law are proposed, and the measurement of rough law variation in the process of rough law ^-F-decomposition is researched. The concepts of law energy and attdbute ^-f-interference degree are presented, which make the variation of rough law become measurable. ^-f-decomposition law energy characteristic theorem, ^-f- decomposition law energy inequality theorem, ^-F-decomposition rough law energy characteristic theorem, and ^-f-decomposition law energy mean value theorem are presented. 展开更多
关键词 function one-direction s-rough sets measurement ^-f-decomposition law F-decomposition rough law attribute ^-f-interference degree rough law energy.
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Hiding dependence-discovery of F-hiding laws and system laws 被引量:2
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作者 Zhou Houyong Huang Shunliang Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第3期543-550,共8页
Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hidin... Function one direction S-rough sets have dynamic characteristics and law characteristics. By using the function one direction S-rough sets, this article presents the concepts of the f-hiding law, F-hiding law, f-hiding law dependence and F-hiding law dependence. Based on the concepts above, this article proposes the hidingdependence theorem of f-hiding laws, the hiding-dependence theorem of F-hiding laws, the hiding-dependence separation theorem, the hiding dependence-discovery principle of unknown laws. Finally, the application of the hiding dependence of hiding laws in the discovery of system laws is given. 展开更多
关键词 function one direction s-rough set function rough set hiding law hiding dependence the hidingdependence theorem application.
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■-law collision and system state recognition 被引量:1
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作者 Shi Kaiquan Chen Hui 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第3期509-514,共6页
Using dual function one direction S-rough sets, this article gives the f-law, the F-law, law distance and the concept of system law collided by the F-law. The characteristics presented by the system law collided by th... Using dual function one direction S-rough sets, this article gives the f-law, the F-law, law distance and the concept of system law collided by the F-law. The characteristics presented by the system law collided by the F-law, the recognition of these characteristics and recognition criterion are also proposed. The dual function one direction S-rough sets is one of the basic forms of function S-rough sets. Its basic theory and application in the study of system law collision are reviewed. 展开更多
关键词 dual function one direction s-rough sets F-law COLLIsION characteristic recognition recognition criterion applications.
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Function S-rough sets and two law forecast
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作者 Fu Haiyan Shi Kaiquan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期332-338,共7页
Function S-rough sets has the properties of dynamics, heredity, and memory. Function S-rough sets is penetrated and crossed with the issue of economic law forecast, then a new forecast model based on function S-rough ... Function S-rough sets has the properties of dynamics, heredity, and memory. Function S-rough sets is penetrated and crossed with the issue of economic law forecast, then a new forecast model based on function S-rough sets namely the two law forecast model is proposed, which includes upper law forecast model and lower law forecast model; and its' implement algorithm is given. Finally, the validity of the model is demonstrated by the forecast for region economic development of Hainan Province. 展开更多
关键词 function s-rough sets two law forecast dynamic economic system
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水驱油田凹-S形含水上升规律表征方法的扩展
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作者 袁迎中 汤紫琪 +4 位作者 凌霄 黄冬梅 于成超 戚志林 严文德 《特种油气藏》 CSCD 北大核心 2024年第6期84-90,共7页
针对水驱油田凹-S形含水上升规律不易诊断且拟合效果较差的问题,综合考虑S形含水上升曲线高含水期偏离直线的情况,以及凹形含水上升曲线对S形含水上升曲线的增强或减弱作用,引入与含水饱和度有关的二次项、对数项及与含水率相关的形态指... 针对水驱油田凹-S形含水上升规律不易诊断且拟合效果较差的问题,综合考虑S形含水上升曲线高含水期偏离直线的情况,以及凹形含水上升曲线对S形含水上升曲线的增强或减弱作用,引入与含水饱和度有关的二次项、对数项及与含水率相关的形态指数n,建立表征凹-S形含水上升规律的扩展型水驱曲线方程。新方程兼具凹形和S形含水上升曲线的特征和优势,拓展了常规含水上升曲线的适用范围,提高了含水上升规律描述的准确性。将研究成果应用于WZ油田,结果表明:利用多元回归分析方法,获得了方程的相关参数,对凹-S形含水上升规律进行综合表征,拟合效果显著提高,拟合的R^(2)达0.9778。在实际应用过程中,可根据已有的生产数据回归得到扩展型水驱曲线方程系数,据此预测不同含水率时的累计产油量,或预测不同累计产油量时的含水率。研究成果对准确分析或预测油田含水上升规律具有重要作用。 展开更多
关键词 凹-s形含水上升规律 水驱曲线 形态指数 表征方法 多元回归
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Darcy定律在测定油松木质部导水特征中的应用 被引量:37
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作者 翟洪波 李吉跃 +1 位作者 李保华 吴文强 《北京林业大学学报》 EI CAS CSCD 北大核心 2001年第4期6-9,共4页
该文介绍了一种测定油松幼树不同部位枝条导水性的方法———冲洗法 .在立地条件相同或相近的情况下 ,选择年龄相近的 4株油松幼树 (8~ 10年生 ) ,用冲洗法进行测量 .在此基础上 ,首次成功地将Darcy定律应用于树木木质部的导水特征分... 该文介绍了一种测定油松幼树不同部位枝条导水性的方法———冲洗法 .在立地条件相同或相近的情况下 ,选择年龄相近的 4株油松幼树 (8~ 10年生 ) ,用冲洗法进行测量 .在此基础上 ,首次成功地将Darcy定律应用于树木木质部的导水特征分析 .结果表明 ,油松幼树在相对分枝级、冠层、分枝方向等不同的情况下 ,比导率表现出不同的变化趋势 .通过对平均比导率 (Ks)差异的进一步分析 ,能够较好地反映出油松木质部的导水特征和其在抗旱中的生态策略 . 展开更多
关键词 darcy定律 油松 冲洗法 比导率 木质部 导水特征
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函数S-粗集与粗规律挖掘-分离 被引量:33
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作者 张萍 史开泉 卢昌荆 《系统工程与电子技术》 EI CSCD 北大核心 2005年第11期1899-1902,共4页
研究了函数S-粗集的本质和特性,及其用于挖掘系统的潜在规律。利用函数S-粗集(单向函数S-粗集,双向函数S-粗集)的数学结构和特性,给出系统中粗规律模型的生成方法。给出了利用函数S-粗集进行系统中的粗规律挖掘与分离的讨论,和系统中粗... 研究了函数S-粗集的本质和特性,及其用于挖掘系统的潜在规律。利用函数S-粗集(单向函数S-粗集,双向函数S-粗集)的数学结构和特性,给出系统中粗规律模型的生成方法。给出了利用函数S-粗集进行系统中的粗规律挖掘与分离的讨论,和系统中粗规律分离的应用。例子证明,函数S-粗集是系统规律挖掘的一个有力工具。 展开更多
关键词 函数s粗集 粗规律生成 粗规律挖掘-分离
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Darcy渗流定律的微观界定及其应用 被引量:2
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作者 许友生 刘慈群 林机 《应用数学和力学》 CSCD 北大核心 2004年第3期253-261,共9页
 将Boltzmann微观方程用Chapman_Enskog展开,结合BGK近似理论得到Navier_Stokes方程,通过在多孔介质的某种表征体元上的不同的方式平均Navier_Stokes方程后得出Darcy渗流定律的一种表示方法。
关键词 darcy定律 BOLTZMANN方程 NAVIER-sTOKEs方程 Chapman-Enskog展开
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增深剂NS增深规律探究 被引量:7
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作者 高普 刘建勇 申晓星 《天津工业大学学报》 CAS 北大核心 2010年第4期53-56,60,共5页
通过对不同组织结构、不同色相的棉、涤纶和毛织物进行增深处理,探讨了增深剂NS的增深规律.研究结果表明:增深剂NS对棉、化纤、毛等各类织物均有比较好的增深效果;增深效果与增深剂的用量呈近似的线性关系;对斜纹织物的增深程度优于平... 通过对不同组织结构、不同色相的棉、涤纶和毛织物进行增深处理,探讨了增深剂NS的增深规律.研究结果表明:增深剂NS对棉、化纤、毛等各类织物均有比较好的增深效果;增深效果与增深剂的用量呈近似的线性关系;对斜纹织物的增深程度优于平纹织物;增深剂对不同色相织物的增深程度有所不同;增深剂对织物的色光基本无影响. 展开更多
关键词 增深规律 增深剂Ns K/s
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饱和土一维有限应变固结控制方程辨析
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作者 王玮瑜 雷国辉 +2 位作者 赵鑫 戴传杰 谷遇溪 《岩土工程学报》 北大核心 2025年第4期829-839,共11页
饱和土的一维有限应变固结控制方程存在多种表达形式,有Eulerian描述和Lagrangian描述,各有不同的控制变量,包括孔隙率、孔隙比、应变、固结比和超静孔压。为明辨其适用条件,考虑固相的压缩性,建立了两种描述方法间基于孔隙率、孔隙比... 饱和土的一维有限应变固结控制方程存在多种表达形式,有Eulerian描述和Lagrangian描述,各有不同的控制变量,包括孔隙率、孔隙比、应变、固结比和超静孔压。为明辨其适用条件,考虑固相的压缩性,建立了两种描述方法间基于孔隙率、孔隙比和位移的坐标转换关系,以及控制变量的时间导数间的转换关系,分析了两种描述方法便于求解的固结问题,并基于Eulerian描述,考虑固相和液相的压缩性和惯性,推导了一维有限应变固结控制方程组,包括连续性方程、动量平衡方程和达西渗流定律。忽略固相和液相的压缩性和惯性后,该方程组简化为一个具有单一控制变量的固结微分方程,通过坐标转换和时间导数转换,也得到了Lagrangian描述下的固结微分方程。将其退化为现有不同形式的有限应变固结控制方程,依据退化过程中涉及的基本假设,明确了这些控制方程的适用条件。 展开更多
关键词 固相和液相 压缩性 Eulerian和Lagrangian空间和时间转换 自然应变 固相和液相惯性 达西定律
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