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An improved limit equilibrium method for rock slope stability analysis under stress-based calculation mode for slip surface
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作者 DENG Dong-ping ZHANG Dian +1 位作者 PENG Yi-hang CHEN Hao-yu 《Journal of Central South University》 2025年第1期262-287,共26页
This study proposes an alternative calculation mode for stresses on the slip surface(SS).The calculation of the normal stress(NS)on the SS involves examining its composition and expanding its unknown using the Taylor ... This study proposes an alternative calculation mode for stresses on the slip surface(SS).The calculation of the normal stress(NS)on the SS involves examining its composition and expanding its unknown using the Taylor series.This expansion enables the reasonable construction of a function describing the NS on the SS.Additionally,by directly incorporating the nonlinear Generalized Hoke-Brown(GHB)strength criterion and utilizing the slope factor of safety(FOS)definition,a function of the shear stress on the SS is derived.This function considers the mutual feedback mechanism between the NS and strength parameters of the SS.The stress constraints conditions are then introduced at both ends of the SS based on the spatial stress relation of one point.Determining the slope FOS and stress solution for the SS involves considering the mechanical equilibrium conditions and the stress constraint conditions satisfied by the sliding body.The proposed approach successfully simulates the tension-shear stress zone near the slope top and provides an intuitive description of the concentration effect of compression-shear stress of the SS near the slope toe.Furthermore,compared to other methods,the present method demonstrates superior processing capabilities for the embedded nonlinear GHB strength criterion. 展开更多
关键词 stability of rock slope nonlinear GHB strength criterion limit equilibrium method stress function on slip surface stress constraint conditions at both ends of slip surface
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THE SPHERICAL FUNCTIONS AND THE CENTRAL LIMIT THEOREM ON SU(2,2)/S(U(2)×U(2))
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作者 杨乔华 张钦 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期867-874,共8页
Let G = SU(2, 2), K = S(U(2) × U(2)), and for l ∈ Z, let {Tl}l∈z be a one-dimensional K-type and let El be the line bundle over G/K associated to Tl. It is shown that the Tl-spherical function on G is g... Let G = SU(2, 2), K = S(U(2) × U(2)), and for l ∈ Z, let {Tl}l∈z be a one-dimensional K-type and let El be the line bundle over G/K associated to Tl. It is shown that the Tl-spherical function on G is given by the hypergeometric functions of several variables. By applying this result, a central limit theorem for the space G/K is obtained. 展开更多
关键词 Spherical function central limit theorem hypergeometric function
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Iterative and adjusting method for computing stream function and velocity potential in limited domains and convergence analysis
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作者 黎爱兵 张立凤 +1 位作者 臧增亮 张云 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第6期687-700,共14页
The stream function and the velocity potential can be easily computed by solving the Poisson equations in a unique way for the global domain. Because of the var- ious assumptions for handling the boundary conditions, ... The stream function and the velocity potential can be easily computed by solving the Poisson equations in a unique way for the global domain. Because of the var- ious assumptions for handling the boundary conditions, the solution is not unique when a limited domain is concerned. Therefore, it is very important to reduce or eliminate the effects caused by the uncertain boundary condition. In this paper, an iterative and ad- justing method based on the Endlich iteration method is presented to compute the stream function and the velocity potential in limited domains. This method does not need an explicitly specifying boundary condition when used to obtain the effective solution, and it is proved to be successful in decomposing and reconstructing the horizontal wind field with very small errors. The convergence of the method depends on the relative value for the distances of grids in two different directions and the value of the adjusting factor. It is shown that applying the method in Arakawa grids and irregular domains can obtain the accurate vorticity and divergence and accurately decompose and reconstruct the original wind field. Hence, the iterative and adjusting method is accurate and reliable. 展开更多
关键词 limited domain stream function velocity potential iteration and adjust-ment CONVERGENCE
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THE AUTOMATIC GENERATION OF LIMIT STATE FUNCTION OF HINGED STRUCTURE
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作者 车维毅 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1991年第12期1187-1193,共7页
In this paper, the theorem of structure continual variation of truss structure in the analysis of structure reliability is derived, and it is used to generate limit state function automatically. We can avoid repeated ... In this paper, the theorem of structure continual variation of truss structure in the analysis of structure reliability is derived, and it is used to generate limit state function automatically. We can avoid repeated assembly of global stiffness matrix and repeated inverse operations of the matrix caused by constant changes of structure topology. A new criterion of degenerate of the structure into mechanism is introduced. The calculation examples are satisfactory. 展开更多
关键词 hinged structure continual variation theorem limit state function
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Right prefrontal cortex is activated for perceiving postural limits: a functional near-infrared spectroscopy study
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作者 Noriyuki Kamata Yoshimi Matsuo +2 位作者 Ayako Matsuya Satoru Inoue Kazuo Abe 《Health》 2009年第3期239-243,共5页
The purpose of this study was to investigate neuronal mechanisms active during the percep-tion of forward postural limits in a standing po-sition and to specify fall-related brain activity using optical functional nea... The purpose of this study was to investigate neuronal mechanisms active during the percep-tion of forward postural limits in a standing po-sition and to specify fall-related brain activity using optical functional near-infrared spectros-copy. The study group included six right-handed, healthy female volunteers (range: 19, 20 years). The optical imaging device comprised 16 opto-des designed to provide 24-channel recording of changes in hemoglobin oxygenation. We meas-ured the changes of oxygenated hemoglobin levels in the frontal region when subjects per-ceived reachability in a standing position. Com- pared with those in other regions, the oxygen-ated hemoglobin levels in the right frontal region compatible with the right prefrontal cortex sig-nificantly increased. This result suggests that brain activities in the right prefrontal cortex are related to perception of reachability. Overesti-mation of postural limits has been reported as one of the risk factor for falling. This overesti-mation might be induced by dysfunction in the prefrontal cortex, resulting in a failure to inhibit a motor program that would have caused a loss of balance in reaching. Activation of the right prefrontal cortex may be a key factor for pre-venting accidental falls in the elderly and in pa-tients with neurological disorders. 展开更多
关键词 POSTURAL limits FALLS functional NEAR-INFRARED Spectroscopy (fNIRS) PREFRONTAL CORTEX (PFC)
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LIMITING WEAK-TYPE BEHAVIORS FOR CERTAIN LITTLEWOOD-PALEY FUNCTIONS 被引量:2
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作者 Xianming HOU Huoxiong WU 《Acta Mathematica Scientia》 SCIE CSCD 2019年第1期11-25,共15页
In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the co... In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the corresponding results for Marcinkiewicz integral and its fractional version with kernels satisfying L_α~q-Dini condition are also given. 展开更多
关键词 limitING BEHAVIORS weak-type bounds LITTLEWOOD-PALEY g-functions Marcinkiewicz integrals L_α~q -Dini conditions
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Inverse Limit of Spaces of Upper Semicontinuous Functions
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作者 张德学 《Northeastern Mathematical Journal》 CSCD 2001年第1期49-52,共4页
Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor o... Given a compact Hausdorff space X, U(X) denotes the compact Hausdorff space of all the upper semicontinuous functions from X to the unit interval with the dual lim inf topology. Then U is an endofunctor on compact Hausdorff space. It is proved in this note that this functor preserves inverse limits. 展开更多
关键词 upper semicontinuous function continuous lattice lim inf convergence inverse limit
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Effect of Intermittent Pneumatic Compression on Functional Level and Quality of Life in Community-Dwelling Older Adults with Limited Ambulation Due to Leg Pain: A Randomized Controlled Trial
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作者 Weerasinghe Mudiyanselage Sujeewa Weerasinghe Thunpaththu Mudiyanselage Upul Sanjeewa Thunpaththu +4 位作者 Weerasinghe Mudiyanselage Sandali Anjana Weerasinghe Weerasinghe Mudiyanselage Shalindu Thushen Weerasinghe Pahala Walpola Gamarallage Shirani Walpola Dissanayaka Mudiyanselage Tharanga Padmini Dissanayaka Angelo Karunaratne 《Health》 2021年第10期1145-1169,共25页
<strong>Background and Purpose:</strong> Walking difficulties are defined as any reduction in speed, balance, or change of gait, causing limited ambulation. These difficulties are a common problem in older... <strong>Background and Purpose:</strong> Walking difficulties are defined as any reduction in speed, balance, or change of gait, causing limited ambulation. These difficulties are a common problem in older adults and may greatly affect their quality of life (QOL) and restrict their personal independence and participation. This study aimed to determine the effect of intermittent pneumatic compression (IPC) on lower leg pain, walking capacity, functional mobility, ankle range of motion (AROM), and QOL of community-dwelling older people with walking difficulties. <strong>Methods:</strong> In this randomized controlled trial, 34 eligible participants with self-reported lower limb pain and limited ambulation were randomized either to the intermittent pneumatic compression intervention group (IPCIG) or static compression control group (SCCG). The IPCIG and SCCG were trained to receive IPC and SC respectively for both lower legs and instructed to continue the application independently at home for 15 minutes per session, 2 sessions a day, 7 days per week for 4 weeks independently at the home. Outcome measures of lower leg pain, AROM, walking capacity, and functional mobility were assessed at baseline and at the first, second, third, and fourth weeks after randomization. Quality of life was assessed at baseline and immediately after the intervention. <strong>Results and Discussion:</strong> IPCIG showed a more significant improvement compared to the SCCG at the post-interventional stage for QOL and all the subscales. The findings show that “80% improved QOL” is 53% higher with the application of IPC than with SC for 4 weeks. The IPCIG showed a more significant improvement in the 6-minute walk test (6 MWT) at the third and fourth weeks compared to the SCCG. A pairwise comparison of mean values of 6 MWT over 4 weeks within the IPCIG showed a significant difference between all the weeks. Pairwise comparisons between groups at each time point showed that the IPCIG showed a more significant improvement in the timed up and go (TUG) test at the third and fourth weeks compared to the SCCG. Pairwise comparison of mean values of TUG test within the IPCIG showed a significant difference over 4 weeks, except between the second and third weeks, fourth week, and third and fourth weeks. The IPCIG showed a more significant improvement in lower leg pain between all weeks except the first week compared to the SCCG. Pairwise comparison of mean values of lower leg pain over 4 weeks within the IPCIG showed a significant difference among all weekly outcomes except between 1 and 2 weeks. The IPCIG showed a more significant improvement in left and right ankle dorsiflexion ROM at the third and fourth weeks compared to the SCCG. <strong>Conclusions:</strong> The IPC was effective in reducing lower leg pain and increasing the AROM and improving the walking capacity, functional mobility level, and QOL of community-dwelling older people with walking disabilities. Walking disability in old age is a common condition requiring physical therapy. Intermittent pneumatic compression can be used as a physical therapy modality for this patient group. 展开更多
关键词 Intermittent Pneumatic Compression functional Level Quality of Life Older Adults limited Ambulation Leg Pain
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BOUNDARY LIMITS OF α-HARMONIC FUNCTIONS
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作者 Gao Qiren 《数学研究》 CSCD 1994年第1期68-71,共4页
BOUNDARYLIMITSOFα-HARMONICFUNCTIONS¥GaoQiren(Dept.ofMath.,XiamenUniv.Xiamen361005)Abstract:Inthispaper,theex... BOUNDARYLIMITSOFα-HARMONICFUNCTIONS¥GaoQiren(Dept.ofMath.,XiamenUniv.Xiamen361005)Abstract:Inthispaper,theexistenceofweighted... 展开更多
关键词 α-Harmonic function α-superharmonic function weighted boundary limits
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Assessment of the 2 Conventional Physiotherapy Sessions Alone versus One Session Associated to Kabat’s Method in the Rehabilitation of Buruli Ulcer Patients (PUB), with Functional Limitations in the District Hospital of Akonolinga, Cameroon
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作者 Fred Dikongue Dikongue Faustin Tsatedem Atemkeng +4 位作者 Joseph Fondop Jean Hubert Donfack Alain Djam Nkomo Banga Mbida Mpoame 《Surgical Science》 2023年第6期428-435,共8页
Buruli ulcer (BU) is a chronic, indolent necrotizing disease of the skin and underlying tissues caused by Mycobacterium ulcerans, which may result in functional disability. This disease is the third most frequent infe... Buruli ulcer (BU) is a chronic, indolent necrotizing disease of the skin and underlying tissues caused by Mycobacterium ulcerans, which may result in functional disability. This disease is the third most frequent infection after leprosy and tuberculosis caused by a mycobacterium. The main objective of this study was to determine comparative effectiveness of conventional physiotherapy alone to its association with Kabat’s method in the management of post-Buruli ulcer functional limitations. This was an interventional randomized, comparative and prospective study. It took place at the district hospital of Akonolinga from the 12<sup>th</sup> June to 12<sup>th</sup> September 2016. The study was included, post-Buruli ulcer patients who matched the eligibility criteria, were under treatment in the physiotherapy unit, and who accepted to participate in our study. A questionnaire on the socio-demographic profile of participants, the ulcer localization, the limitation stage, previous medical history and functional mobility assessment scale was administered to the subjects before and after the intervention which lasted for twelve weeks. We had 2 groups: the case group received association of Kabat technique to conventional physiotherapy and the control group received conventional physiotherapy alone. We had 22 patients, 11 patients for the experimental group, 11 patients for the control group. The mean age was 26.18 years, 54.5% of female participation, 68.2% of leg localization, 59.1% patients with severe limitations of functional mobility, and preference for traditional medication 95.5%. After evaluation of efficiency, we concluded that there was no statistically significant difference between the two treatment protocols. Further studies with larger sample size are recommended. 展开更多
关键词 Buruli Ulcer functional limitations PHYSIOTHERAPY Kabat Technique
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PADE APPROXIMANTS AS LIMITS OF RATIONAL FUNCTIONS OF BEST APPROXIMATION IN ORLICZ SPACE
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作者 Li Jialiang Central China Normal University, China Department of Mathematics Central Normal University 《Analysis in Theory and Applications》 1994年第2期74-82,共9页
In this paper, we prove that the best rational approximation of a given analytic function in Orlicz space L~*(G), where G = {|z|≤∈}, converges to the Pade approximants of the function as the measure of G approaches ... In this paper, we prove that the best rational approximation of a given analytic function in Orlicz space L~*(G), where G = {|z|≤∈}, converges to the Pade approximants of the function as the measure of G approaches zero. 展开更多
关键词 RATIONAL MATH PADE APPROXIMANTS AS limitS OF RATIONAL functionS OF BEST APPROXIMATION IN ORLICZ SPACE AS
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THE INTEGRAL AS A FUNCTION OF THE UPPER LIMIT AND AN ANALYTICAL SOLUTION TO PLANE STRAIN DRAWING AND EXTRUSION
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作者 赵德文 赵志业 张强 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1990年第8期759-765,共7页
A kinematically admissible velocity field which is different from Avitzur's is established in Cartesian Coordinates. An upper-bound analytical solution to strip drawing andextrusion is obtained by using the integr... A kinematically admissible velocity field which is different from Avitzur's is established in Cartesian Coordinates. An upper-bound analytical solution to strip drawing andextrusion is obtained by using the integral as a function of the upper limit in this paper. 展开更多
关键词 THE INTEGRAL AS A function OF THE UPPER limit AND AN ANALYTICAL SOLUTION TO PLANE STRAIN DRAWING AND EXTRUSION
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THE LIMIT CYCLE BIFURCATIONS OF A WHIRLING PENDULUM WITH PIECEWISE SMOOTH PERTURBATIONS
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作者 杨纪华 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期1115-1144,共30页
This paper deals with the problem of limit cycles for the whirling pendulum equation x=y,y=sin x(cosx-r)under piecewise smooth perturbations of polynomials of cos x,sin x and y of degree n with the switching line x=0.... This paper deals with the problem of limit cycles for the whirling pendulum equation x=y,y=sin x(cosx-r)under piecewise smooth perturbations of polynomials of cos x,sin x and y of degree n with the switching line x=0.The upper bounds of the number of limit cycles in both the oscillatory and the rotary regions are obtained using the Picard-Fuchs equations,which the generating functions of the associated first order Melnikov functions satisfy.Furthermore,the exact bound of a special case is given using the Chebyshev system.At the end,some numerical simulations are given to illustrate the existence of limit cycles. 展开更多
关键词 whirling pendulum limit cycle Melnikov function Picard-Fuchs equation Chebyshev system
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The Ill-Posedness of Derivative Interpolation and Regularized Derivative Interpolation for Non-Bandlimited Functions
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作者 Weidong Chen 《Applied Mathematics》 2022年第1期87-100,共14页
In this paper, the ill-posedness of derivative interpolation is discussed, and a regularized derivative interpolation for non-bandlimited signals is presented. The convergence of the regularized derivative interpolati... In this paper, the ill-posedness of derivative interpolation is discussed, and a regularized derivative interpolation for non-bandlimited signals is presented. The convergence of the regularized derivative interpolation is studied. The numerical results are given and compared with derivative interpolation using the Tikhonov regularization method. The regularized derivative interpolation in this paper is more accurate in computation. 展开更多
关键词 Nonband-limited function Derivative Interpolation ILL-POSEDNESS REGULARIZATION
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基于ICF的智力残疾儿童言语功能障碍和沟通活动受限特征与康复干预
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作者 易玲 周静 +3 位作者 陈雪芬 陈川帆 陈科伊 董慧繁 《中国康复理论与实践》 北大核心 2025年第4期398-405,共8页
目的系统分析智力残疾儿童言语和沟通障碍的特点,设计整体性的康复方案。方法运用《国际功能、残疾和健康分类》(ICF)的理论和方法,从身体功能和结构、活动和参与、环境因素等多个维度对智力残疾儿童的言语和沟通功能障碍特征进行深入... 目的系统分析智力残疾儿童言语和沟通障碍的特点,设计整体性的康复方案。方法运用《国际功能、残疾和健康分类》(ICF)的理论和方法,从身体功能和结构、活动和参与、环境因素等多个维度对智力残疾儿童的言语和沟通功能障碍特征进行深入分析。在言语康复和特殊教育情境下实施综合干预方法。结果在身体功能和结构方面,言语功能障碍常常表现为语言的心理功能、发音功能、言语的流畅性和节律功能等障碍。在活动和参与层面,表现为沟通障碍,包括说话、倾听、对话以及人际互动等方面可能存在障碍或困难。环境因素,如家庭支持、同伴态度、专业服务以及辅助沟通技术的可及性,对智力残疾儿童的言语功能和沟通功能的发展有重要的影响。本研究基于ICF架构提出了儿童的言语功能和沟通活动功能的系统性评估方法,强调从整体视角理解智力残疾儿童的言语功能障碍和沟通活动障碍,注重沟通活动功能对智力残疾儿童的学习和日常生活的影响。在言语康复治疗和教育康复情境下,针对智力残疾儿童的言语障碍和沟通活动障碍的特点,设计个别化的干预方法,注重培养儿童的功能性沟通技能,并将其融入到日常生活和教育活动中。辅助和替代沟通技术、自然情境下的语言干预、视觉支持以及同伴介导等干预均是有效的康复措施。结论本研究运用ICF架构和方法,对智力残疾儿童的言语功能和沟通活动功能进行了系统分析,从身体功能和结构、活动和参与以及环境因素3个层面,系统探讨了智力残疾儿童的言语功能和沟通活动功能的特征,并且提出了在言语康复治疗和教育康复情景下,推动智力残疾儿童言语功能和沟通活动功能发展的系统性方法,包括设计个别化干预方法、辅助技术应用、视觉辅助支持以及同伴介导等措施。 展开更多
关键词 智力残疾 儿童 言语功能障碍 沟通活动受限 国际功能、残疾和健康分类
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局域与区域过程对生物多样性的影响:群落构建的饱和与开放
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作者 韩博平 王璐 +2 位作者 刘振元 周婷婷 黄琦 《水生生物学报》 北大核心 2025年第1期29-40,共12页
自MacArthur和Wilson建立岛屿生物地理学的平衡模型以来,以生物多样性为核心的群落生态学进入了范式转变的阶段,从更为广阔的视角重新审视群落构建这一决定生物多样性的核心机制。与经典群落生态学不同,新范式的群落生态学将局域群落视... 自MacArthur和Wilson建立岛屿生物地理学的平衡模型以来,以生物多样性为核心的群落生态学进入了范式转变的阶段,从更为广阔的视角重新审视群落构建这一决定生物多样性的核心机制。与经典群落生态学不同,新范式的群落生态学将局域群落视为一个开放的单元,认为区域群落和集合群落内部的物种扩散与迁移是平衡局域群落中物种灭绝的关键力量。局域群落的物种组成与多样性是局域过程与区域过程共同作用的产物,局域过程包括生物过滤和非生物过滤,而区域过程包含了影响物种形成的地理、历史和进化过程。局域过程与区域过程在局域群落构建中的相对重要性具有时空依赖性。文章回顾了半个世纪以来群落生态学研究范式的变化,从群落构建、物种库与群落饱和性等概念入手,系统地介绍了基于局域-区域物种丰富度关系分析区域与局域过程相对重要性的方法及其局限性,并介绍了克服这些局限性的辅助分析方法。物种库是生物地理学的基础概念,物种库的物种数量与组成记录了地理与区域尺度上历史上发生的生态与进化过程,物种库为表述区域过程的作用提供了可定量化的变量。局域群落是区域物种库所有物种的子集,局域群落构建是这一子集形成的过程与机制。局域-区域物种丰富度关系是用于比较群落构建中区域与局域过程的相对重要性的直观方法,这种关系的非线性反映了群落的饱和性。由于这种关系受到空间尺度、环境条件和群落中物种特性的影响,在判读群落是否饱和时需要结合其他理论与经验方法。对于物种均处于同一营养级的群落而言,当局域尺度足够小时,容易检测到群落的饱和性。而对于包括多个营养级的群落,局域-区域物种丰富度关系的解读需要考虑跨营养级的相互作用。环境选择与种间相互作用都是通过性状实现的,实际观测的局域群落与随机群落的功能多样性比较可以辅助判断局域过程的性质与强度。准确定义物种库是理解局域群落构建与生物多样性维持机制的前提,同时应考虑物种库的大小与功能属性,这将促进我们对群落结构与生物多样性格局的理解与认识。 展开更多
关键词 物种库 区域群落 扩散限制 环境过滤 物种库功能多样性
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基于深度置信网络的旋转机械在线故障诊断
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作者 郭俊杰 郭正红 《计算机测量与控制》 2025年第1期60-68,共9页
针对现有旋转机械在线故障诊断算法所存在的数据遍历耗时长,检测准确率低,故障分类准确率低等不足,提出一种基于深度置信网络的故障诊断算法;先基于受限的玻尔兹曼机搭建深度置信网络框架,利用数据标签在输入层和后端的受限玻尔兹曼机... 针对现有旋转机械在线故障诊断算法所存在的数据遍历耗时长,检测准确率低,故障分类准确率低等不足,提出一种基于深度置信网络的故障诊断算法;先基于受限的玻尔兹曼机搭建深度置信网络框架,利用数据标签在输入层和后端的受限玻尔兹曼机之间建立联系;然后利用k-means算法压缩聚类处理数据集降低数据集的规模和复杂度;最后在不同故障特征的分类诊断方面,引入加入核函数的SVM分类算法,提升对不同机械故障类型的分类精度;实验结果显示,提出的旋转机械故障在线诊断方案的迭代效率高,数据遍历耗时少,训练集和测试集F1指标的分别为97.9%和97.4%,优于传统故障诊断算法。 展开更多
关键词 深度置信网络 改进K-MEANS算法 受限的玻尔兹曼机 核函数 SVM
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具有医疗资源有限和Ornstein-Uhlenbeck过程的随机SIR传染病模型研究
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作者 刘晓虎 曹虹 聂麟飞 《应用数学》 北大核心 2025年第1期170-181,共12页
基于医疗资源的有限性和疾病的传播规律,提出一类具有Ornstein-Uhlenbeck过程和一般发生率的随机SIR传染病模型.首先,讨论模型全局正解的存在唯一性并给出疾病灭绝性的充分条件.其次,通过构造合适的Lyapunov函数并应用It^o公式等方法,... 基于医疗资源的有限性和疾病的传播规律,提出一类具有Ornstein-Uhlenbeck过程和一般发生率的随机SIR传染病模型.首先,讨论模型全局正解的存在唯一性并给出疾病灭绝性的充分条件.其次,通过构造合适的Lyapunov函数并应用It^o公式等方法,得到模型平稳分布的存在性.此外,通过求解Fokker-Planck方程,给出模型在拟地方病平衡点附近的密度函数的具体形式.最后通过数值模拟解释主要的理论结果并探讨随机扰动对疾病传播的影响. 展开更多
关键词 随机传染病模型 医疗资源有限 灭绝性 平稳分布 概率密度函数
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腹腔镜限量解剖性肝切除术对中期胆囊癌患者近远期肝功能的影响
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作者 陈小彬 于伯华 +1 位作者 黄毅龙 谢家敏 《癌症进展》 2025年第7期767-769,773,共4页
目的探讨腹腔镜限量解剖性肝切除术(LLAH)对中期胆囊癌患者近远期肝功能的影响。方法依据手术方式的不同将68例胆囊癌患者分为对照组(n=30)和观察组(n=38),对照组患者接受传统解剖性肝切除术,观察组患者接受LLAH术。比较两组患者的肝功... 目的探讨腹腔镜限量解剖性肝切除术(LLAH)对中期胆囊癌患者近远期肝功能的影响。方法依据手术方式的不同将68例胆囊癌患者分为对照组(n=30)和观察组(n=38),对照组患者接受传统解剖性肝切除术,观察组患者接受LLAH术。比较两组患者的肝功能指标[丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、总胆红素(TBIL)]、围手术期指标和并发症发生情况。结果术后1周、1个月、6个月、1年,两组患者ALT、AST、TBIL均呈先升高后降低趋势,且观察组患者ALT、AST、TBIL水平均低于对照组,差异均有统计学意义(P﹤0.05)。观察组患者手术时间长于对照组,住院时间短于对照组,术中出血量少于对照组,差异均有统计学意义(P﹤0.05)。观察组患者的并发症总发生率为5.26%,低于对照组患者的23.33%,差异有统计学意义(P﹤0.05)。结论中期胆囊癌患者采用LLAH术治疗,有利于近远期肝功能的恢复,还能够减少术中出血量,降低术后并发症发生风险,缩短住院时间,值得临床推广。 展开更多
关键词 腹腔镜限量解剖性肝切除术 胆囊癌 肝功能 并发症
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极限两类问题中海涅定理的应用
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作者 张慧芬 张珍 《山西大同大学学报(自然科学版)》 2025年第1期36-38,共3页
海涅定理是山东大学版高等数学课本中函数极限性质中的一部分内容,书上内容篇幅有限,定理内容描述又抽象,使得学生理解起来有点困难。从海涅定理的应用着手,阐述了用其解决极限问题中两类题型的可行性。通过分类举例思想,使得学生对这... 海涅定理是山东大学版高等数学课本中函数极限性质中的一部分内容,书上内容篇幅有限,定理内容描述又抽象,使得学生理解起来有点困难。从海涅定理的应用着手,阐述了用其解决极限问题中两类题型的可行性。通过分类举例思想,使得学生对这一知识点掌握得更具体化、实用化,完成学科构建的目标,能够轻松独立完成课后作业题。 展开更多
关键词 函数极限 数列极限 海涅定理
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