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用结构分数法考评学业成绩的尝试
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作者 李文贵 《中小学教育与管理》 2003年第4期48-48,共1页
关键词 结构分数法 学业成绩 试卷分数 操作方 考评方 学生自评
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Prolongation Structure of Semi-discrete Nonlinear Evolution Equations 被引量:6
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作者 BAI Yong-Qiang WU Ke +1 位作者 GUO Han-Ying ZHAO Wei-Zhong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4X期591-600,共10页
Based on noncommutative differential calculus, we present a theory of prolongation structure for semidiscrete non/inear evolution equations. As an illustrative example, a semi-discrete model of the non/inear SchrSding... Based on noncommutative differential calculus, we present a theory of prolongation structure for semidiscrete non/inear evolution equations. As an illustrative example, a semi-discrete model of the non/inear SchrSdinger equation is discussed in terms of this theory and the corresponding Lax pairs are also given. 展开更多
关键词 noncommutative differential calculus prolongation structure Lax pair
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Molecular reconstruction model based on structure oriented lumping and group contribution methods 被引量:7
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作者 Jincai Chen Zhou Fang Tong Qiu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1677-1683,共7页
Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in pet... Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping(SOL) and group contribution(GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy(MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data. 展开更多
关键词 Molecular reconstruction Structure oriented lumping Group contribution Monte Carlo Maximum information entropy
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Studying surface structure in desert areas using multiple kinds of surface wave data 被引量:1
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作者 Cheng Suo Gang Tian Zhanjie Shi 《Applied Geophysics》 SCIE CSCD 2007年第1期1-7,共7页
Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan ... Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan Desert area, we use the multi-channel analysis of surface wave (MASW) method to process multi-channel shallow surface wave records to determine the near surface velocity structure in the desert area. We also process, analyze, and compare the surface waves in many-trace records extracted from the oil exploration shot gathers in the area. We show that the MASW method can determine detailed shallow velocity structure in desert areas and the many-trace records can be used to get detailed deep geological structure. The combination of the two different datasets can obtain the exact velocity structure upper 60 m depth in the survey area. 展开更多
关键词 desert area near surface structure shot records multi-channel analysis of surface wave.
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Determination of a Pore Structure Parameter of Porous Media by Analysis of Percolation Network Model 被引量:1
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作者 辛峰 王富民 +1 位作者 廖晖 李绍芬 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第4期287-293,共7页
According to the simulation of nitrogen sorption process in porous media with three-dimensional network model, and the analysis for such a process with percolation theory, a new method is proposed to determine a pore ... According to the simulation of nitrogen sorption process in porous media with three-dimensional network model, and the analysis for such a process with percolation theory, a new method is proposed to determine a pore structure parameter--mean coordination number of pore network, which represents the connectivity among a great number of pores. Here the 'chamber-throat' model and the Weibull distribution are used to describe the pore geometry and the pore size distribution respectively. This method is based on the scaling law of percolation theory after both effects of sorption thermodynamics and pore size on the sorption hysteresis loops are considered. The results show that it is an effective procedure to calculate the mean coordination number for micro- and meso-porous media. 展开更多
关键词 coordination number porous media percolation theory network model SORPTION
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Coalbody structure classification method based on dual-lateral and RXO crossplot analysis 被引量:6
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作者 Qiang CHEN Hui-Fang YAO +1 位作者 Suo-Liang CHANG Jun LIU 《Journal of Coal Science & Engineering(China)》 2013年第4期522-529,共8页
According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonabl... According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonably located. Inte- grated the data of coal macrostructure characteristics, coal petrography analysis and coal gas production test, it studies the rela- tionship between coalbody structure and amplitude variation of different well logging data, and the tectonic coal recognition method with well logging data in fresh-water mud invasion. The results show that: the anomalous response of natural gamma ray, neutron, density and apparent resistivity does not reflect the coalbody structure type. In fresh-water drilling mud invasion, using the crossplot technique of dual-lateral, RXO resistivity response and the coalbody structure can classify granulated coal accurately; the proposed method is of good practicability and high reliability. 展开更多
关键词 coalbody structure mud filtrate invasion coal core depth-correction dual-lateral and RXO resistivity permeability
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Membership Proof and Verification in Authenticated Skip Lists Based on Heap 被引量:1
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作者 Shuanghe Peng Zhige Chen Deen Chen 《China Communications》 SCIE CSCD 2016年第6期195-204,共10页
How to keep cloud data intact and available to users is a problem to be solved. Authenticated skip list is an important data structure used in cloud data integrity verification. How to get the membership proof of the ... How to keep cloud data intact and available to users is a problem to be solved. Authenticated skip list is an important data structure used in cloud data integrity verification. How to get the membership proof of the element in authenticated skip list efficiently is an important part of authentication. Kaouthar Blibech and Alban Gabillon proposed a head proof and a tail proof algorithms for the membership proof of elements in the authenticated skip list. However, the proposed algorithms are uncorrelated each other and need plateau function. We propose a new algorithm for computing the membership proof for elements in the authenticated skip list by using two stacks, one is for storing traversal chain of leaf node, the other is for storing authentication path for the leaf. The proposed algorithm is simple and effective without needing plateau function. It can also be applicable for other similar binary hash trees. 展开更多
关键词 authenticated skip list max heap membership proof STACK algorithms
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Experimental and Numerical Investigations on Vibration Characteristics of a Loaded Ship Model
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作者 Pu Liang Ming Hong Zheng Wang 《Journal of Marine Science and Application》 CSCD 2015年第3期234-243,共10页
In this paper, the vibration characteristics of the structure in the finite fluid domain are analyzed using a coupled finite element method. The added mass matrix is calculated with finite element method (FEM) by 8-... In this paper, the vibration characteristics of the structure in the finite fluid domain are analyzed using a coupled finite element method. The added mass matrix is calculated with finite element method (FEM) by 8-node acoustic fluid elements. The vibration characteristics of the structure in the finite fluid domain are calculated combining structure FEM mass matrix. By writing relevant programs, the numerical analysis on vibration characteristics of a submerged cantilever rectangular plate in finite fluid domain and loaded ship model is performed. A modal identification experiment for the loaded ship model in air and in water is conducted and the experiment results verify the reliability of the numerical analysis. The numerical method can be used for further research on vibration characteristics and acoustic radiation problems of the structure in the finite fluid domain. 展开更多
关键词 loaded ship model vibration characteristics finite element method (FEM) added mass matrix natural frequency modal identification finite fluid domain
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Deployment simulation of cable-strut structures considering cable sliding 被引量:2
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作者 CAI JianGuo FENG Jian WANG Kai 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第12期3263-3269,共7页
The influence of cable sliding on the deployment of foldable cable-strut structures was studied in this paper. In order to develop an effective program for the cable sliding program, two-node cable element based on th... The influence of cable sliding on the deployment of foldable cable-strut structures was studied in this paper. In order to develop an effective program for the cable sliding program, two-node cable element based on the analytical solution of elastic cate- nary was studied. Then the cable sliding stiffness was defined as the ratio of the variation of the cable force to the variation of the cable length. To validate the proposed numerical method, analyses of two examples given in references were carried out. The results show that the method given in this paper is accurate and effective, which can be used to model the cable sliding in cable structures. Finally, the deployment process of a foldable cable-strut structure, which is composed of four-bar linkages and cables, was discussed. It can be found that the effect of cable sliding on the behavior of cable-strut structures is significant. The length changes of active cables are smaller when the cable sliding is considered. Moreover, the nodal coordinate changes also become faster when the numerical model is with cable sliding. 展开更多
关键词 DEPLOYMENT elastic catenary cable-strut structures cable sliding nonlinear analysis
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A collocation interval analysis method for interval structural parameters and stochastic excitation 被引量:13
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作者 QI WuChao QIU ZhiPing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第1期66-77,共12页
Uncertainty propagation, one of the structural engineering problems, is receiving increasing attention owing to the fact that most significant loads are random in nature and structural parameters are typically subject... Uncertainty propagation, one of the structural engineering problems, is receiving increasing attention owing to the fact that most significant loads are random in nature and structural parameters are typically subject to variation. In the study, the collocation interval analysis method based on the first class Chebyshev polynomial approximation is presented to investigate the least favorable responses and the most favorable responses of interval-parameter structures under random excitations. Compared with the interval analysis method based on the first order Taylor expansion, in which only information including the function value and derivative at midpoint is used, the collocation interval analysis method is a non-gradient algorithm using several collocation points which improve the precision of results owing to better approximation of a response function. The pseudo excitation method is introduced to the solving procedure to transform the random problem into a deterministic problem. To validate the procedure, we present numerical results concerning a building under seismic ground motion and aerofoil under continuous atmosphere turbulence to show the effectiveness of the collocation interval analysis method. 展开更多
关键词 uncertainty propagation interval analysis Taylor series expansion Chebyshev polynomial Pseudo excitation method
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Elastic catenary cable element considering frictional slip effect 被引量:10
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作者 CAI JianGuo LIM James +2 位作者 FENG Jian XU YiXiang WANG Kai 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第6期1489-1495,共7页
Conventional analysis methods of cable structures do not consider sliding of cables inside the joint,which may lead to inaccuracy of the theoretical behavior of the structure.In order to develop an effective method fo... Conventional analysis methods of cable structures do not consider sliding of cables inside the joint,which may lead to inaccuracy of the theoretical behavior of the structure.In order to develop an effective method for cable sliding,a two-node cable element based on the analytical solution for an elastic catenary was studied.The cable sliding stiffness and the effect of friction were investigated.To validate the proposed numerical method,analyses of two examples given in the literature were conducted.The results demonstrated that the method given in this paper is accurate and effective,and can take into account cable sliding in cable structures.In addition,it was shown that the effect of cable sliding on the behavior of cable structures is significant.It was also shown that the friction at the support hampers the flow of the cable force,leading to unequal cable tensions on both sides of the support. 展开更多
关键词 CABLE elastic catenary FRICTION cable sliding nonlinear analysis
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Tomographic TR-PIV measurement of coherent structure spatial topology utilizing an improved quadrant splitting method 被引量:18
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作者 YANG ShaoQiong JIANG Nan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第10期1863-1872,共10页
In this paper,we calculated the spatial local-averaged velocity strains along the streamwise direction at four spatial scales according to the concept of spatial local-averaged velocity structure function by using the... In this paper,we calculated the spatial local-averaged velocity strains along the streamwise direction at four spatial scales according to the concept of spatial local-averaged velocity structure function by using the three-dimensional three-component database of time series of velocity vector field in the turbulent boundary layer measured by tomographic time-resolved particle image velocimetry.An improved quadrant splitting method,based on the spatial local-averaged velocity strains together with a new conditional sampling phase average technique,was introduced as a criterion to detect the coherent structure topology.Furthermore,we used them to detect and extract the spatial topologies of fluctuating velocity and fluctuating vorticity whose center is a strong second-quadrant event(Q2) or a fourth-quadrant event(Q4).Results illustrate that a closer similarity of the multi-scale coherent structures is present in the wall-normal direction,compared to the one in the other two directions.The relationship among such topological coherent structures and Reynolds stress bursting events,as well as the fluctuating vorticity was discussed.When other burst events are surveyed(the first-quadrant event Q1 and the third-quadrant event Q3),a fascinating bursting period circularly occurs:Q4-S-Q2-Q3-Q2-Q1-Q4-S-Q2-Q3-Q2-Q1 in the center of such topological structures along the streamwise direction.In addition,the probability of the Q2 bursting event occurrence is slightly higher than that of the Q4 event occurrence.The spatial instable singularity that almost simultaneously appears together with typical Q2 or Q4 events has been observed,which is the main character of the mutual induction mechanism and vortex auto-generation mechanism explaining how the turbulence is produced and maintained. 展开更多
关键词 turbulent boundary layer coherent structure BURST TR-PIV Q2/Q4 local-averaged velocity strain quadrant splittingmethod
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Investigation on emissive properties of peroskite-type oxide LSMO with grating surface
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作者 HUANG JinGuo XUAN YiMin LI Qiang 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第1期220-225,共6页
This paper aims to investigate thermal radiative characteristics of thermochrornic material La0.825Sr0.175MnO3(LSMO) with one-dimensional grating structured surfaces. The dielectric function of LSMO was calculated b... This paper aims to investigate thermal radiative characteristics of thermochrornic material La0.825Sr0.175MnO3(LSMO) with one-dimensional grating structured surfaces. The dielectric function of LSMO was calculated by K-K approach. Numerical calculation was conducted to obtain spectral emittance distribution of such surfaces with different structural parameters using the finite difference time domain (FDTD) method. It was found that the spectral emittance of LSMO structured surface exhib- ited the feature of selective enhancement due to the excitation of microcavity effect. The effects of structural parameters on spectral emittance indicated that the desired radiative enhancement could be achieved by the rational design of the structural parameters of grating. The temperature dependence of averaged emittance of LSMO was also calculated, The results showed that LSMO with grating structured surface had a better thermochromic performance compared with LSMO with smooth surface. 展开更多
关键词 GRATING thermochromic materials EMISSION
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MATHEMATICAL DESCRIPTION OF GROWTH OF MULTIPLE ROOT BRANCHING STRUCTURE IN A PLANT
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作者 ARUN KUMAR 《International Journal of Biomathematics》 2013年第3期1-10,共10页
An existing growth model of Edelstien is extended and modified for multiple root branching structure or root hairs of any plant. Numerical and analytical solutions for the model are developed and compared. In the deri... An existing growth model of Edelstien is extended and modified for multiple root branching structure or root hairs of any plant. Numerical and analytical solutions for the model are developed and compared. In the derivation it is assumed that multiple root branches are attached to the root surface that acts as a continuous source of new tips. The numerical scheme is derived with anticipation of the fact that comparison with experimental data may necessitate a more complicated model. 展开更多
关键词 Uptake parameter asymptotic matching van Genuchten formula relativewater content.
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