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Dynamic Characteristics of Functionally Graded Timoshenko Beams by Improved Differential Quadrature Method
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作者 Xiaojun Huang Liaojun Zhang +1 位作者 Hanbo Cui Gaoxing Hu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1647-1668,共22页
This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node... This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node distribution.Firstly,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam cross-section.Then,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse displacement.Based on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic equations.Finally,the first several natural frequencies of the beam can be calculated.The feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature. 展开更多
关键词 Timoshenko beams functionally graded materials dynamic characteristics natural frequency improved differential quadrature method
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Alzheimer's disease with sleep insufficiency:a cross-sectional study on correlations among clinical characteristics,orexin,its receptors,and the bloodbrain barrier 被引量:1
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作者 Peng Guo Wen-Jing Zhang +13 位作者 Teng-Hong Lian Wei-Jiao Zhang Ming-Yue He Ya-Nan Zhang Yue Huang Du-Yu Ding Hui-Ying Guan Jing-Hui Li Dan-Ning Li Dong-Mei Luo Wei-Jia Zhang Hao Yue Xiao-Min Wang Wei Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第8期1757-1762,共6页
Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-br... Previous studies have shown that reduced sleep duration,sleep fragmentation,and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling.At the same time,blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease.However,currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency.This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital.Patients were divided into two groups:those with insufficient sleep(sleep duration≤6 hours,n=19,age 61.58±8.54 years,10 men)and those with normal sleep durations(sleep duration>6 hours,n=31,age 63.19±10.09 years,18 men).Demographic variables were collected to evaluate cognitive function,neuropsychiatric symptoms,and activities of daily living.The levels of orexin,its receptor proteins,and several blood-brain barrier factors were measured in cerebrospinal fluid.Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains.Furthermore,levels of orexin and its receptors were upregulated in the cerebrospinal fluid,and the blood–brain barrier was destroyed.Both these events precipitated each other and accelerated the progression of Alzheimer's disease.These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation.Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease. 展开更多
关键词 Alzheimer's disease blood-brain barrier cerebrospinal fluid clinical characteristics cognitive function matrix metalloproteinases matrix metalloproteinase-3 neuropsychiatric symptoms orexin signaling sleep insufficiency
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LAD PARAMETER ESTIMATION of SaS BASED on SAMPLE CHARACTERISTIC FUNCTION
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作者 陈高波 《科技信息》 2010年第25期I0028-I0028,I0027,共2页
Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS... Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS is discussed. The example illustrates that the algorithm is feasible and efficient. 展开更多
关键词 概率 密度函数 计算方法 迭代参数
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Synthetically quantitative evaluation function of characteristic parameters on CO_2 arc welding process 被引量:4
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作者 俞建荣 蒋力培 +2 位作者 史耀武 孙振国 王军波 《China Welding》 EI CAS 2001年第1期19-26,共8页
The statistical probability and their variation regularity of the measurable characteristic parameters in the CO 2 arc welding droplet short circuiting transfer process have been studied. The statistical analysis sh... The statistical probability and their variation regularity of the measurable characteristic parameters in the CO 2 arc welding droplet short circuiting transfer process have been studied. The statistical analysis shows that the sensitivity of each characteristic parameter with regard to the variation of the short circuiting transfer process is different. The sensitivity of 4 kinds among these characteristic parameters is more intense than that of the short circuiting transfer frequency. In order to take account of the synthetic influence of these characteristic parameters, by means of the characteristic parameters synthetic value, a quantitative evaluation function is built up to describe and evaluate the short circuiting transfer process of CO 2 arc welding in real time. The testing shows that the evaluation function can give a suitable synthetic valuation for the short circuiting transfer process with a variety of welding variables. 展开更多
关键词 CO 2 arc welding process characteristic parameters quantitative evaluation function
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The Characteristic Function Method and Its Application to (1 + 1)-Dimensional Dispersive Long Wave Equation 被引量:2
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作者 Medhat M. Helal Mohammad L. Mekky Emad A. Mohamed 《Applied Mathematics》 2012年第1期12-18,共7页
In this paper, the characteristic function method is applied to seek traveling wave solutions of nonlinear partial differential equations in a unified way. We consider the Wu-Zhang equation (which describes (1 + 1)-di... In this paper, the characteristic function method is applied to seek traveling wave solutions of nonlinear partial differential equations in a unified way. We consider the Wu-Zhang equation (which describes (1 + 1)-dimensional disper-sive long wave). The equations governing the wave propagation consist of a pair of non linear partial differential equations. The characteristic function method reduces the system of nonlinear partial differential equations to a system of nonlinear ordinary differential equations which is solved via the shooting method, coupled with Rungekutta scheme. The results include kink-profile solitary wave solutions, periodic wave solutions and rational solutions. As an illustrative example, the properties of some soliton solutions for Wu-Zhang equation are shown by some figures. 展开更多
关键词 characteristic function Method Wu-Zhang EQUATION
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Relations Between Characteristic Function,Positive P-Representation and Coherent Thermal State 被引量:1
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作者 FAN Hong-Yi XU Xing-Lei Department of Material Science and Engineering,University of Science and Technology of China,Hefei 230026,China2 Department of Physics,Shanghai Jiao Tong University,Shanghai 200030,China3 Department of Physics,Heze University,Heze 274015,China 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第7期67-70,共4页
We employ the coherent thermal states(a kind of entangled states)in thermal field dynamics to establisha complete entangled state formalism expressing pseudo-classical representations of density operator for light fie... We employ the coherent thermal states(a kind of entangled states)in thermal field dynamics to establisha complete entangled state formalism expressing pseudo-classical representations of density operator for light field.Especially,the relationship between the coherent thermal state and the characteristic function and the positive Prepresentation in quantum optics theory are obtained. 展开更多
关键词 coherent thermal state characteristic function positive P-representation
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Characteristic Functional Structure of Infinitesimal Symmetry Transformations for Nonholonomic System 被引量:1
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作者 张宏彬 陈立群 《Journal of Shanghai University(English Edition)》 CAS 2005年第2期134-138,共5页
It was proved that velocity-dependent infinitesima l symmetry transformations of nonholonomic systems have a characteristic functio nal structure, which could be formulated by means of an auxiliary symmetry tra nsform... It was proved that velocity-dependent infinitesima l symmetry transformations of nonholonomic systems have a characteristic functio nal structure, which could be formulated by means of an auxiliary symmetry tra nsformation function and is manifestly dependent upon constants of motion of th e system. An example was given to illustrate the applicability of the results. 展开更多
关键词 analytical mechanics nonholonomic system velocity-dependent infinitesimal symmetry transformation characteristic functional structure constant of motion.
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Natural dynamic characteristics of a circular cylindrical Timoshenko tube made of three-directional functionally graded material 被引量:3
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作者 Ye TANG Jiye XU Tianzhi YANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2022年第4期479-496,共18页
The natural dynamic characteristics of a circular cylindrical tube made of three-directional(3 D)functional graded material(FGM)based on the Timoshenko beam theory are investigated.Hamilton’s principle is utilized to... The natural dynamic characteristics of a circular cylindrical tube made of three-directional(3 D)functional graded material(FGM)based on the Timoshenko beam theory are investigated.Hamilton’s principle is utilized to derive the novel motion equations of the tube,considering the interactions among the longitudinal,transverse,and rotation deformations.By dint of the differential quadrature method(DQM),the governing equations are discretized to conduct the analysis of natural dynamic characteristics.The Ritz method,in conjunction with the finite element method(FEM),is introduced to verify the present results.It is found that the asymmetric modes in the tube are controlled by the 3 D FGM,which exhibit more complicated shapes compared with the unidirectional(1 D)and bi-directional(2 D)FGM cases.Numerical examples illustrate the effects of the axial,radial,and circumferential FGM indexes as well as the supported edges on the natural dynamic characteristics in detail.It is notable that the obtained results are beneficial for accurate design of smart structures composed from multi-directional FGM. 展开更多
关键词 circular cylindrical tube three-directional(3D)functionally graded material(FGM) asymmetric mode natural dynamic characteristic differential quadrature method(DQM)
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Characteristic and Functions of Architectural Cultures in Traditional Villages of Ningbo 被引量:1
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作者 HUANG Shuna 《Journal of Landscape Research》 2015年第5期57-58,60,共3页
Further promotion of urbanization has resulted in the broken integrity of architectural environment and cultural system of traditional villages, and some traditional villages with historical architectural styles have ... Further promotion of urbanization has resulted in the broken integrity of architectural environment and cultural system of traditional villages, and some traditional villages with historical architectural styles have been on the verge of extinction. Against the background of building "beautiful Zhejiang and good life", Ningbo City has to optimize the livable environment continuously, integrate natural, humanistic, green, characteristic and comfortable elements into the beautiful countryside construction, thus it is urgent to explore the cultural characteristics and functions of architectural environment in traditional villages. Cultural characteristics and functions of architectural environment in traditional villages of Ningbo should be more systematic, legalized, and scientific. This paper reviewed concepts and cultural connotations of traditional villages, and integrated cultural characteristics and functions of regional architectural environment in traditional villages of Ningbo, and provided references for theoretic researches on the formation of characteristic regional architectural cultures in traditional villages of Ningbo. 展开更多
关键词 Traditional village Regionality Architectural cultural characteristics Architectural cultural functions
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Global Avalanche Characteristics of Boolean Functions by Concatenation
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作者 Zepeng Zhuo Jinfeng Chong +1 位作者 Ruirui Yu Mingsheng Ren 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第3期91-96,共6页
In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,f... In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,for the function f = f_1‖f_2,the cross-correlation function of f_1,f_2 in the special condition are studied.In this case,f,f_1,f_2 must be in desired form.By computing their sum-of-squares indicators,the crosscorrelation function between f_1,f_2 is obtained.Secondly,for the function g = f_1‖f_2‖f_3‖f_4,by analyzing the relation among their auto-correlation functions,their sum-of-squares indicators are investigated.Based on them,the sum-of-squares indicators of functions obtained by Canteaut et al.are investigated.The results show that the correlation property of g is good when the correlation properties of Boolean functions f_1,f_2,f_3,f_4 are good. 展开更多
关键词 BOOLEAN function CROSS-CORRELATION function GLOBAL AVALANCHE characteristics sum-of-squaresindicator
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CRITERION AND APPRAISABLE FUNCTION OF SIZE CHARACTERISTICS
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作者 Xie, Hengxing Yi, Guohong Li, Songren 《中国有色金属学会会刊:英文版》 EI CSCD 1997年第1期9-13,共5页
CRITERIONANDAPPRAISABLEFUNCTIONOFSIZECHARACTERISTICS①XieHengxing,YiGuohong,LiSongrenDepartmentofMineralEngin... CRITERIONANDAPPRAISABLEFUNCTIONOFSIZECHARACTERISTICS①XieHengxing,YiGuohong,LiSongrenDepartmentofMineralEngineering,CentralSou... 展开更多
关键词 SIZE SIZE characteristicS CRITERION appraisable function
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Multilevel Characteristic Basis Function Method with ACA for Accelerated Solution of Electrically Large Scattering Problems
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作者 Li Chenlu Sun Yufa +1 位作者 Wang Zhonggen Wang Guohua 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期449-454,共6页
The multilevel characteristic basis function method(MLCBFM)with the adaptive cross approximation(ACA)algorithm for accelerated solution of electrically large scattering problems is studied in this paper.In the convent... The multilevel characteristic basis function method(MLCBFM)with the adaptive cross approximation(ACA)algorithm for accelerated solution of electrically large scattering problems is studied in this paper.In the conventional MLCBFM based on Foldy-Lax multiple scattering equations,the improvement is only made in the generation of characteristic basis functions(CBFs).However,it does not provide a change in impedance matrix filling and reducing matrix calculation procedure,which is time-consuming.In reality,all the impedance and reduced matrix of each level of the MLCBFM have low-rank property and can be calculated efficiently.Therefore,ACA is used for the efficient generation of two-level CBFs and the fast calculation of reduced matrix in this study.Numerical results are given to demonstrate the accuracy and efficiency of the method. 展开更多
关键词 multilevel characteristic basis function method(MLCBFM) adaptive cross approximation(ACA) characteristic basis functions(CBFs) electromagnetic scattering
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Genetic-algorithm-based balanced distribution of functional characteristics for machines
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作者 王国新 杜景军 阎艳 《Journal of Beijing Institute of Technology》 EI CAS 2015年第1期49-57,共9页
In order to make reconfigurable manufacturing system (RMS) adapt to the fluctuations of production demand with the minimum number of reconflgurations in its full life cycle, we presented a method to design RMS based... In order to make reconfigurable manufacturing system (RMS) adapt to the fluctuations of production demand with the minimum number of reconflgurations in its full life cycle, we presented a method to design RMS based on the balanced distribution of functional characteristics for ma- chines. With this method, functional characteristics were classified based on machining functions of cutting-tools and machining accuracy of machines. Then the optimization objective was set as the to- tal shortest mobile distance that all the workpieces are moved from one machine to another, and an improved genetic algorithm (GA) was proposed to optimize the configuration. The elitist strategy was used to enhance the global optimization ability of GA, and excellent gene pool was designed to maintain the diversity of population. Software Matlab was used to realize the algorithm, and a case study of simulation was used to evaluate the method. 展开更多
关键词 reconfigurable manufacturing systems balanced distribution functional characteristics genetic algorithm
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Alternative Derivation of the Propagator in Polar Coordinates by Feynman's Physical Interpretation of the Characteristic Function
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作者 QIAN Shang-Wu CHAN King-Man GU Zhi-Yu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第11期529-532,共4页
This article revisits Feynman's characteristic function, and points out the insight and usefulness of hisphysical interpretation. As an example, the tedious and rather long derivation of the propagator in polar co... This article revisits Feynman's characteristic function, and points out the insight and usefulness of hisphysical interpretation. As an example, the tedious and rather long derivation of the propagator in polar coordinatescan be easily and clearly obtained by merely using Feynman's physical intepretation of the characteristic function andsome well-known results of central force problem. 展开更多
关键词 Feynman's characteristic function PROPAGATOR in POLAR COORDINATES
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Construction of Transgenic Crop Germplasm Effective Function and Characteristic Analysis
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作者 DING Guangzhou WANG Xiaowei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2008年第2期68-75,共8页
Germplasm effect reflects the quantitative relation between production ability of germplasm elements and yield (quality) of a certain crop, which can be shown by mathematic function, namely, germplasm effect functio... Germplasm effect reflects the quantitative relation between production ability of germplasm elements and yield (quality) of a certain crop, which can be shown by mathematic function, namely, germplasm effect function. Germplasm effect of a crop variety is an aggregation of many effective factors, and is restrained by different effective factors; constant increase of any one effect of germplasm elements would lead to law of effect decline, therefore, possible modes of transgenic crops effect function were deduced according to the law of effect decline. The possible modes of single transgenic germplasm effect function and multi-transgenic germplasm effect regression equation were discussed, and the characteristics of germplasm effect regression equation were analyzed in this paper. 展开更多
关键词 transgenic crops germplasm effect function mode and characteristic germplasm operation
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Numerical modeling calculation for the spatial distribution characteristics of horizontal field transfer functions
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作者 龚绍京 陈化然 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2001年第6期676-684,共9页
Applying 3-dimension finite difference method, the distribution characteristics of horizontal field transfer functions for rectangular conductor have been computed, and the law of distribution for Re-part and Im-part ... Applying 3-dimension finite difference method, the distribution characteristics of horizontal field transfer functions for rectangular conductor have been computed, and the law of distribution for Re-part and Im-part has been given. The influences of source field period, the conductivity, the buried depth and the length of the conductor on the transfer functions were studied. The extrema of transfer functions appear at the center, the four corners and around the edges of conductor, and move with the edges. This feature demonstrates that around the edges are best places for transfer functions' observation. 展开更多
关键词 numerical modeling 3-D finite difference method horizontal field transfer function spatial distribution characteristics
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CHARACTERISTIC FUNCTIONS OF BILINEAR TIME SERIES MODEL
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作者 贾民平 钟秉林 黄仁 《Journal of Southeast University(English Edition)》 EI CAS 1993年第1期9-13,共5页
Bilinear time series models are of importance to nonlinear time seriesanalysis.In this paper,the autocovariance function and the relation between linearand general bilinear time series models are derived.With the help... Bilinear time series models are of importance to nonlinear time seriesanalysis.In this paper,the autocovariance function and the relation between linearand general bilinear time series models are derived.With the help of Volterra seriesexpansion,the impulse response function and frequency characteristic function of thegeneral bilinear time series model are also derived. 展开更多
关键词 time series analysis BILINEAR characteristic function Volterra series expansion Green's function autocovariance function
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Study on Plant Community Characteristics and Ecological Functions of Mingyue Park in Jingzhou City
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作者 Yingjie LI Zijing XIANG +1 位作者 Xianjie LAN Yang ZHANG 《Agricultural Biotechnology》 CAS 2022年第5期38-41,49,共5页
[Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzho... [Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzhou City, as well as the ecological functions of plants in cooling, humidification, shading, and noise reduction. [Methods] A quadart method was used to investigate plant communitues of Mingyue Park in Jingzhou City. [Results] There were 141 species in the park, including 44 tree speceies, 35 shrub speceies, and 62 herb speceies. The arber-shrub-grass structure was the dominant plant community structure. The Simpson index(D), Shannon-Wiener index(H) and Pielou index(J) of the herb layer were higher than those of the tree layer and the shrub layer, and the shrub layer was the lowest. The results of ecological function research showed that the plant communities had a significant shading effect and a certain ability to reduce noise. The comprehensive conclusion showed that the ecological function indexes of the arbor-shrub-grass structure in Mingyue Park were significantly higher than those of the arbor-shrub structure and the single-tree structure. In order to improve the ecological benefits of plant communities in Mingyue Park, the plant diversity can be increased in the later construction to enrich community structures. [Conclusions] This study evaluated the ecological benefits of plant communities in Mingyue Park, and provides a scientific basis for the plant configuration of parks in Jingzhou and other regions. 展开更多
关键词 Mingyue Park Community structure Plant diversity Ecology function Community characteristics
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Research on Functional Characteristics of Karst Eco-economic Compound System in Guizhou Province 被引量:2
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作者 LUO Kun-yan Xingyi Normal University for Nationalities,Xingyi 562400,China 《Asian Agricultural Research》 2011年第3期113-119,共7页
Based on the eco-economy theory,this paper analyzed the characteristics of the components of eco-economic compound system of karst region in Guizhou Province.The functional characteristics of eco-economic compound sys... Based on the eco-economy theory,this paper analyzed the characteristics of the components of eco-economic compound system of karst region in Guizhou Province.The functional characteristics of eco-economic compound system of karst region in Guizhou Province were analyzed.The functional characteristics were as follows:low biological production of Guizhou Province;weak capacity of ecosystem;slow speed of storage and accumulation of material and serious environmental pollution;low production and efficiency of energy;serious wastes of energy.On the basis of functional characteristics of eco-economic compound System in Karst region.Some views in terms of maintenance and reconstruction of compound system,were put forward,including laying stress on improving ecological system;choosing and cultivating the advanced species that suit the Karst region;improving the amount and speed of material accumulation,at the same time,introducing into advanced production technologies and management experience;reducing the energy efficiency of each section in economic system and improving the transformation efficiency of energy. 展开更多
关键词 Eco-economic COMPOUND system KARST region of Guizh
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REFERENCE FUNCTIONAL AND CHARACTERISTIC SPACE FOR LAGRANGE AND BERNSTEIN OPERATORS
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作者 S.De Marchi M.Morandi Cecchi 《Analysis in Theory and Applications》 1995年第4期6-14,共9页
This paper deals with the description and the representation of polynomials defined over n-simplices, The polynomials are computed by using two recurrent schemes: the Neville-Aitken one for the Lagrange interpolating ... This paper deals with the description and the representation of polynomials defined over n-simplices, The polynomials are computed by using two recurrent schemes: the Neville-Aitken one for the Lagrange interpolating operator and the De Casteljau one for the Bernstein-Bezier approximating operator. Both schemes fall intothe framework of transformations of the form where the F iare given numbers (forexample, at the initial step they coincide with the values of the function on a given lattice), and the coefficients (x) are linear polynomials valued in x and x is fixed. A general theory for such sequence of transformations can be found in [2] where it is also proved that these tranformations are completely characterized in term of a linear functional, reference functional. This functional is associated with a linear space., characteristic space.The concepts of reference functionals and characteristic spaces will be used and we shall prove the existence of a characteristic space for the reference functional: associated with these operators. 展开更多
关键词 REFERENCE functionAL AND characteristic SPACE FOR LAGRANGE AND BERNSTEIN OPERATORS
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