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Almost Fixed Points and Fixed Points of Upper [Lower] Semicontinuous Multimap on Locally G-convex Spaces 被引量:3
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作者 朴勇杰 《Northeastern Mathematical Journal》 CSCD 2005年第4期391-396,共6页
In this paper, we use the well known KKM type theorem for generalized convex spaces due to Park (Elements of the KKM theory for generalized convex spaces, Korean J. Comp. Appl. Math., 7(2000), 1-28) to obtain an a... In this paper, we use the well known KKM type theorem for generalized convex spaces due to Park (Elements of the KKM theory for generalized convex spaces, Korean J. Comp. Appl. Math., 7(2000), 1-28) to obtain an almost fixed point theorem for upper [resp., lower] semicontinuous multimaps in locally G-convex spaces, and then give a fixed point theorem for upper semicontinuous multimap with closed Γ-convex values. 展开更多
关键词 G-convex space upper [lower] semicontinuous locally G-convex space ahnost fixed point property ahnost Γ-convex
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Lower rotating point nutrient vessels of sural nerve flap with distant pedicled repairing soft tissue defect of foot and ankle
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作者 林松庆 《外科研究与新技术》 2005年第3期175-176,共2页
To explore lower rotating potint nutrient vessels of sural nerve flap with distant pedicled repairing the soft tissue defect of foot and ankle.Methods Lay a foundation of anatomic studying from february 2003 to March ... To explore lower rotating potint nutrient vessels of sural nerve flap with distant pedicled repairing the soft tissue defect of foot and ankle.Methods Lay a foundation of anatomic studying from february 2003 to March 2004,using lower rotating point nutrient vessels of sural nerve flap with distant pedicled repairing the soft tissue defect of foot and ankle in 11 cases.Cause of injuring:traffic accident 7 cases,crushing 1 case,saw injury 1 case,skin cancer 1 case,chronic ulcer 1 case.Areas:foot heel 6 cases,shank lower section 2 cases,heel tendon 2 cases,the distant back of the foot 1 case.Using the flap axis point was 1~3 cm above the pin of the external heel,average 2 cm.The scope of the flap was 6.0 cm×8.0 cm~12.0 cm~18.0 cm.Results All sural nerve flaps were alive.Of them,2 cases have distant part necrosis,accompanying with subcutaneous tissue,1 case heels after change dressings,another heels after skin grafting.All case can walk as usual,the flap was wear-resisting and keenly feel.Conclusion Lower rotating point nutrient vessels of sural nerve flap,donner area was fine,available area was large,skin in the pink,easy grafting,without main blood vessel damage,survival rate high,it is a good donner area in repairing around heel,foot and shank lower section.7 refs,1 tab. 展开更多
关键词 lower rotating point nutrient vessels of sural nerve flap with distant pedicled repairing soft tissue defect of foot and ankle
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下刚果盆地早白垩世Pointe Indienne组湖相浊积岩特征及石油地质意义 被引量:2
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作者 余烨 蔡灵慧 +3 位作者 尹太举 王莉 张兴强 徐吉丰 《岩性油气藏》 CSCD 北大核心 2020年第6期12-21,共10页
为了明确下刚果盆地盐下重点勘探层系,采用沉积学、石油地质学的相关理论和方法,结合区域地质背景、钻测井数据和分析测试结果等资料,对下刚果盆地早白垩世Pointe Indienne组湖相浊积岩特征及其石油地质意义进行了探讨,并建立了Pointe I... 为了明确下刚果盆地盐下重点勘探层系,采用沉积学、石油地质学的相关理论和方法,结合区域地质背景、钻测井数据和分析测试结果等资料,对下刚果盆地早白垩世Pointe Indienne组湖相浊积岩特征及其石油地质意义进行了探讨,并建立了Pointe Indienne组大型浊积扇的发育模式。结果表明:该浊积岩形成于深湖相沉积环境,其叠置砂体具有典型的浊流沉积特征,发育典型的鲍玛序列及特征沉积构造;该浊积砂岩为长石岩屑质石英砂岩或杂砂岩,其成分成熟度低、结构成熟度较差,表现为快速堆积的重力流沉积特征;该浊积砂岩内部识别出了多套完整和不完整的鲍玛序列,显示了厚层块状浊积岩和薄层或微层浊积岩的组合形式,指示了浊积扇内扇、中扇、外扇的沉积特征;该浊积砂岩为中孔低渗储层,与Pointe Indienne组上段和下段发育的厚层优质烃源岩接触,具有良好的生、储、盖组合,是下刚果盆地盐下油气勘探的重点层系。 展开更多
关键词 浊积岩 深湖相 pointe Indienne组 早白垩世 下刚果盆地
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A Review on Flow Boiling of the Fluid with Lower Boiling Point in Micro-Channels
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作者 ZHANG Zhiqiang JIA Li DANG Chao 《Journal of Thermal Science》 SCIE EI CSCD 2024年第1期1-17,共17页
With the advancement of micro machining technology,the high-heat-flux removal from miniature electronic devices and components has become an attractive topic.Flow boiling in micro-channels is an optimal form of heat t... With the advancement of micro machining technology,the high-heat-flux removal from miniature electronic devices and components has become an attractive topic.Flow boiling in micro-channels is an optimal form of heat transfer and has been widely employed in high-heat-flux cooling applications.This comprehensively-reviewed article focused on the available recent literatures of experimental investigation regarding the flow boiling heat transfer and unstable behaviors of the fluid with lower boiling point in micro-channels.The thermal-fluid characteristics and potential heat transfer mechanisms of low-boiling-point fluids flow boiling in different narrow passages were summarized and discussed.The literatures regarding the pressure drop and occurrence of the unstable phenomena existing in two-phase flow boiling process were also discussed.The emphasis was given to the heat transfer enhancement methods as well as instability elimination,and various methods such as modification of surface and channel flow geometries were considered.Some future researches in the field of micro-scale flow boiling were suggested. 展开更多
关键词 flow boiling lower boiling point fluids mini/micro-channels INSTABILITIES enhancement SUPPRESSION
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湖相重力流沉积特征及沉积模式——以下刚果盆地A区块白垩系Pointe Indienne组为例
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作者 余烨 蔡灵慧 +4 位作者 尹太举 张兴强 许泓 黄俨然 曹涛涛 《沉积学报》 CAS CSCD 北大核心 2022年第1期34-46,共13页
应用深水沉积学和地震沉积学的相关理论,通过岩心观察描述、钻测井资料分析及平面沉积相编图,对下刚果盆地A区块白垩系Pointe Indienne组深水重力流的类型、沉积特征、垂向沉积组合及沉积模式进行了探讨分析,指出该地区发育砂质碎屑流... 应用深水沉积学和地震沉积学的相关理论,通过岩心观察描述、钻测井资料分析及平面沉积相编图,对下刚果盆地A区块白垩系Pointe Indienne组深水重力流的类型、沉积特征、垂向沉积组合及沉积模式进行了探讨分析,指出该地区发育砂质碎屑流、泥质碎屑流、浊流及与重力流形成过程相关的滑动—滑塌沉积,并总结了该深水重力流的沉积模式。结果表明:砂质碎屑流沉积以块状层理细砂岩为主,含大型漂浮泥砾和泥岩撕裂屑;泥质碎屑流沉积以泥级碎屑为主,含有少量的暗色泥岩碎屑和砂质团块,见"泥包砾"结构;浊流沉积以发育完整或不完整的鲍马序列为特征;滑动—滑塌沉积具有明显的剪切滑移面,可见旋转火焰构造、砂岩扭曲杂乱分布及褶皱变形层;纵向上可识别出4种类型的重力流沉积垂向组合,以多期砂质碎屑流沉积叠置和砂质碎屑流沉积与浊流沉积叠置最为常见;研究区深水重力流沉积可分为上部扇、中部扇和外部扇3部分,上部扇以主水道沉积为主;中部扇以辫状水道和溢岸沉积为主,砂体厚度较大;外部扇以朵叶体沉积和薄层浊积岩为主,砂体厚度相对较薄。 展开更多
关键词 重力流沉积 沉积模式 pointe Indienne组 白垩系 下刚果盆地
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MONOTONE POINTS IN ORLICZ-BOCHNER SEQUENCE SPACES
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作者 Wanzhong Gong Zhongrui Shi 《Analysis in Theory and Applications》 2012年第4期301-311,共11页
In Orlicz-Bochner sequence spaces endowed with Orlicz norm and Luxemburg norm, points of lower monotonicity, upper monotonicity, lower local uniform monotonicity and upper local uniform monotonicity are characterized.
关键词 Banach lattice Orlicz-Bochner space Luxemburg norm Orlicz norm upper(lower monotone point upper lower locally uniformly monotone point
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COMMON FIXED POINT OF GENERALIZED WEAKLY CONTRACTIVE MAPS IN PARTIAL METRIC SPACES 被引量:5
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作者 Vesna COJBAIC RAJIC Stojan RADENOVIC Sunny CHAUHAN 《Acta Mathematica Scientia》 SCIE CSCD 2014年第4期1345-1356,共12页
In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, ext... In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, extend, unify, enrich and complement many existing results in the literature. Example are given showing the validaty of our results. 展开更多
关键词 Common fixed point lower semi-continuous function weak (ψ Ф)-contraction partial metric space
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STABILITY OF MAJORLY EFFICIENT POINTS AND SOLUTIONS IN MULTIOBJECTIVE PROGRAMMING 被引量:2
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作者 GUGUOHUA HUYUDA 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第3期313-324,共12页
In this paper, we obtain some other properties of the majorly efficient points and solutions of the multiobjective optimization presellted in two previous papers of Hu. By decomposing the major cone, which is non-poin... In this paper, we obtain some other properties of the majorly efficient points and solutions of the multiobjective optimization presellted in two previous papers of Hu. By decomposing the major cone, which is non-pointed, non-convex and non-closed into a finite union of disjoint strictly supported pointed convex cones, we discuss the continuous perturbations of the decision space. Several sufficient conditions for the continuity of the sets of majorly efficiellt points and solutions are given. 展开更多
关键词 Multiobjective optimization STABILITY point-to-set map upper(lower) semicontinuity
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A GENERALIZATION OF BROWDER'S FIXED POINT THEOREM WITH APPLICATIONS
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作者 张石生 张宪 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第9期943-951,共9页
The purpose of this paper is to obtain a generalization of the famous Browder's fixed point theorem and some equivalent forms. As application, these results are utilized to study the existence problems of fixed po... The purpose of this paper is to obtain a generalization of the famous Browder's fixed point theorem and some equivalent forms. As application, these results are utilized to study the existence problems of fixed points and nearest points. 展开更多
关键词 transfer open(closed)mapping Browder's fixed point theorem transfer upper (lower) semi_continuous function
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Singular perturbation of a second-order three-point boundary value problem for nonlinear systems
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作者 林晓洁 刘文斌 《Journal of Shanghai University(English Edition)》 CAS 2009年第1期16-19,共4页
This paper deals with the existence of solutions to a singularly perturbed second-order three-point boundary value problem for nonlinear differential systems. The authors construct an appropriate generalized lower- an... This paper deals with the existence of solutions to a singularly perturbed second-order three-point boundary value problem for nonlinear differential systems. The authors construct an appropriate generalized lower- and upper-solution pair, a concept defined in this paper, and employ the Nagumo conditions and algebraic boundary layer functions to ensure the existence of solutions of the problem. The uniformly valid asymptotic estimate of the solutions is given as well. The differential systems have nonlinear dependence on all order derivatives of the unknown. 展开更多
关键词 singular perturbation nonlinear systems three-point boundary value problem upper and lower solutions
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The Existence of Positive Solutions of p-Laplacian Non-homogeneous Multi-point Boundary Value Problems
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作者 TIAN Ya 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第2期190-195,共6页
We study the following nonlinear m-point p-Laplacian boundary value problem with non-homogenous condition: (Φp(u′)′)+f(t, u, u′)=0, 0<t<1, u′(0)=0, u(1)-Σ m-2 i=1 kiu(ξi)=λ, where Φp(s)=|s|p-2 s, p>... We study the following nonlinear m-point p-Laplacian boundary value problem with non-homogenous condition: (Φp(u′)′)+f(t, u, u′)=0, 0<t<1, u′(0)=0, u(1)-Σ m-2 i=1 kiu(ξi)=λ, where Φp(s)=|s|p-2 s, p>1, λ>0, ki≥0(i = 1, 2, ··· , m-2), 0<ξ1<ξ2< ··· <ξm-2<1,0 < Σm-2 i=1 ki<1. Under sufficient conditions, we show that there exists a positive number λ* such that the problem has at least one positive solution for 0 < λ < λ and no solution for λ > λ*. The proof is based on the Schauder fixed point theorem and upper-lower technics. 展开更多
关键词 p-Laplacian operator NON-HOMOGENEOUS Shauder fixed-point theorem upperlower technics
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The Existence and Uniqueness of Positive Solutions for a Singular Nonlinear Three-Point Boundary Value Problems
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作者 Yao Dong Baoqiang Yan 《Journal of Applied Mathematics and Physics》 2018年第12期2600-2620,共21页
Using the method of lower and upper solutions, we study the following singular nonlinear three-point boundary value problems: , where K ∈ C[0,1] ,0 α η < 1 and λ is a positive parameter and present the existenc... Using the method of lower and upper solutions, we study the following singular nonlinear three-point boundary value problems: , where K ∈ C[0,1] ,0 α η < 1 and λ is a positive parameter and present the existence, uniqueness, and the dependency on parameters of the positive solutions under various assumptions. Our result improves those in the previous literatures. 展开更多
关键词 Three-point Boundary Value Problem Positive Solution lower and UPPER Solutions EIGENVALUE and EIGENFUNCTION
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ON THE EXISTENCE OF SOLUTION OF A NONLINEAR TWO-POINT BOUNDARY VALUE PROBLEM ARISING FROM A LIQUID METAL FLOW
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作者 程晓良 应玮婷 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2005年第4期351-356,共6页
In this paper, we discuss the existence of solution of a nonlinear two-point boundary value problem with a positive parameter Q arising in the study of surfacetension-induced flows of a liquid metal or semiconductor. ... In this paper, we discuss the existence of solution of a nonlinear two-point boundary value problem with a positive parameter Q arising in the study of surfacetension-induced flows of a liquid metal or semiconductor. By applying the Schauder's fixed-point theorem, we prove that the problem admits a solution for 0 ≤ Q ≤ 14.306.It improves the result of 0 ≤ Q < 1 in [2] and 0 ≤ Q ≤ 13.213 in [3]. 展开更多
关键词 边值问题 Schauder固定点 估计解 存在性
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Motion Planning for a Cable-Driven Lower Limb Rehabilitation Robot with Movable Distal Anchor Points
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作者 Jinghang Li Keyi Wang +1 位作者 Yanzhuo Wang Chao Wang 《Journal of Bionic Engineering》 SCIE EI CSCD 2023年第4期1585-1596,共12页
This article introduces a cable-driven lower limb rehabilitation robot with movable distal anchor points(M-CDLR).The traditional cable-driven parallel robots(CDPRs)control the moving platform by changing the length of... This article introduces a cable-driven lower limb rehabilitation robot with movable distal anchor points(M-CDLR).The traditional cable-driven parallel robots(CDPRs)control the moving platform by changing the length of cables,M-CDLR can also adjust the position of the distal anchor point when the moving platform moves.The M-CDLR this article proposed has gait and single-leg training modes,which correspond to the plane and space motion of the moving platform,respectively.After introducing the system structure configuration,the generalized kinematics and dynamics of M-CDLR are established.The fully constrained CDPRs can provide more stable rehabilitation training than the under-constrained one but requires more cables.Therefore,a motion planning method for the movable distal anchor point of M-CDLR is proposed to realize the theoretically fully constrained with fewer cables.Then the expected trajectory of the moving platform is obtained from the motion capture experiment,and the motion planning of M-CDLR under two training modes is simulated.The simulation results verify the effectiveness of the proposed motion planning method.This study serves as a basic theoretical study of the structure optimization and control strategy of M-CDLR. 展开更多
关键词 Bionic robot Cable-driven parallel robot(CDPR) lower limb rehabilitation robot Movable anchor point Motion planning SIMULATION
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Fall preventive gait trajectory planning of a lower limb rehabilitation exoskeleton based on capture point theory 被引量:1
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作者 Mei-ying DENG Zhang-yi MA +5 位作者 Ying-nan WANG Han-song WANG Yi-bing ZHAO Qian-xiao WEI Wei YANG Can-jun YANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2019年第10期1322-1330,共9页
We study the balance problem caused by forward leaning of the wearer's upper body during rehabilitation training with a lower limb rehabilitation exoskeleton. The instantaneous capture point is obtained by modelin... We study the balance problem caused by forward leaning of the wearer's upper body during rehabilitation training with a lower limb rehabilitation exoskeleton. The instantaneous capture point is obtained by modeling the human-exoskeleton system and using the capture point theory. By comparing the stability region with instantaneous capture points of different gait phases, the balancing characteristics of different gait phases and changes to the equilibrium state in the gait process are analyzed. Based on a model of the human-exoskeleton system and the condition of balance of different phases, a trajectory correction strategy is pro-posed for the instability of the human-exoskeleton system caused by forward leaning of the wearer's upper body. Finally, the reliability of the trajectory correction strategy is verified by carrying out experiments on the Zhejiang University Lower Extremity Exoskeleton. The proposed trajectory correction strategy can respond to forward leaning of the upper body in a timely manner. Additionally, in the process of the center of gravity transferred from a double-support phase to a single-support phase, the ratio of gait cycle to zero moment point transfer is reduced correspondingly, and the gait stability is improved. 展开更多
关键词 lower EXTREMITY EXOSKELETON CAPTURE point GAIT phase Balance of HUMAN-MACHINE system
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Upper(Lower) Monotone Coefficient of a Point in Orlicz Function Spaces
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作者 Hong Shi MA Xin Bo LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第5期585-598,共14页
The calculation expressions of upper (lower) monotone coefficient of a point in Orlicz function spaces are given.
关键词 Orlicz function space LM upper lower monotone coefficient upper lower locally uniform monotone point
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基于检测框下边沿的单目视觉车辆测距研究
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作者 刘宏利 王雨林 +1 位作者 邵磊 李季 《计算机科学》 CSCD 北大核心 2024年第S01期415-420,共6页
对车辆测距是当今驾驶领域的热门研究方向。针对传统测距方法测距精度受到车型大小影响的问题以及前车存在的X轴偏移问题,提出了基于检测框下边沿中心点的车辆测距模型。该模型通过使用单目视觉摄像头及车辆检测算法获取前方车辆的位置... 对车辆测距是当今驾驶领域的热门研究方向。针对传统测距方法测距精度受到车型大小影响的问题以及前车存在的X轴偏移问题,提出了基于检测框下边沿中心点的车辆测距模型。该模型通过使用单目视觉摄像头及车辆检测算法获取前方车辆的位置信息,并通过车辆检测框得出的下边沿中心点坐标,以及相机安装的俯仰角信息综合建立了车辆测距模型,解决了车型大小带来的误差问题;通过构建三角函数模型,解决了前车相对于实验车辆存在的X轴分量问题,并优化改进了前车安全距离的判定方式;设定车尾矩形框中心点横坐标与车辆外接矩形框宽度的比值λ,根据λ取值分情况讨论,使该模型更符合场景应用需要。并提出了基于测距关键点的逆透视变换模型,减小了测距误差。实验表明,改进后测距模型的测距精度不受车型大小的影响且能考虑到前车位置的X轴分量问题,改进后的测距模型相对于传统测距模型,测距误差降低了约1.5%,且测距精度明显提高。 展开更多
关键词 单目视觉 测距 逆透视变换 检测框下边沿中心点 目标检测
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固体激光器可靠性评估技术研究
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作者 杨丽颖 曹剑 《电工技术》 2024年第4期184-186,共3页
主要介绍了在获得固体激光器的失效数据下,利用AIC、BIC信息量最小准则的分布类型选择方法,确定固体激光器的失效分布类型,再利用已有的数据,对其可靠性进行有效的评估,得到固体激光器MTBF的点估计和不同置信度下的MTBF置信下限,为该产... 主要介绍了在获得固体激光器的失效数据下,利用AIC、BIC信息量最小准则的分布类型选择方法,确定固体激光器的失效分布类型,再利用已有的数据,对其可靠性进行有效的评估,得到固体激光器MTBF的点估计和不同置信度下的MTBF置信下限,为该产品设计定型和生产决策提供管理信息。 展开更多
关键词 可靠性评估 分布选择 点估计 置信下限
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A FOUR-POINT BOUNDARY VALUE PROBLEM FOR NONLINEAR EQUATION
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作者 蒋达清 《Annals of Differential Equations》 1997年第1期68-76,共9页
This paper deals with a four-point boundary value problem [φ(u')]' = f(t, u, u'),a < t < b with u(a) - u(ao) = A, u(b) - u(bo) = B, where a < a0 <b0 < b.
关键词 A four-point boundary value problem Upper and lower solutions EXISTENCE Nagumo condition.
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三层正放四角锥预应力网架稳定性分析
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作者 高福聚 徐敬 +1 位作者 宋昱豪 尹宏志 《低温建筑技术》 2024年第2期79-82,90,共5页
网架以其优良的工程性能成为大跨度结构的首选结构类型之一。为改善传统网架结构在大跨度条件下变形大、用钢量大的缺陷,文中通过对网架施加预应力的方式,达到增强结构整体刚度和承载能力的目的。预应力的施加必然会对网架的稳定性能造... 网架以其优良的工程性能成为大跨度结构的首选结构类型之一。为改善传统网架结构在大跨度条件下变形大、用钢量大的缺陷,文中通过对网架施加预应力的方式,达到增强结构整体刚度和承载能力的目的。预应力的施加必然会对网架的稳定性能造成影响,其中支承形式对网架结构的稳定性影响较大。并通过对网架施加不同预应力后进行稳定性分析,得到不同预应力布索方式对网架稳定性影响,为网架的实际工程建设提供参考。 展开更多
关键词 下弦多点支承 三层正放四角锥网架 网架稳定性分析
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