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浅析实际问题数学化方法
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作者 李晓东 《数学教学研究》 1997年第1期16-20,共5页
浅析实际问题数学化方法李晓东(西北师大二附中730070)随着数学高考命题的不断改革,近年来的考题不断的出现利用数学知识解决实际问题的题目.比如1993年第22题,1995年第24题,1996年第24题.这些试题主要... 浅析实际问题数学化方法李晓东(西北师大二附中730070)随着数学高考命题的不断改革,近年来的考题不断的出现利用数学知识解决实际问题的题目.比如1993年第22题,1995年第24题,1996年第24题.这些试题主要考查学生如何将一个用文字语言叙述的... 展开更多
关键词 数学化方法 实际问题 等差数列 运油率 耗油量 数列问题 平均价格 基本不等式 通项公式 目标函数
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微积分学中若干问题的数学化归方法 被引量:1
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作者 余惠霖 《柳州职业技术学院学报》 2011年第2期18-21,共4页
从数学文化教育的角度,分析和讨论微积分学中若干问题的数学化归方法。
关键词 微积分学 数学方法 数学教育
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数学模型化方法刍议
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作者 戴勇 《黔南民族师范学院学报》 2001年第6期16-18,共3页
本文通过对数学模型 ,数学模型化方法及其基本步骤作论述 。
关键词 数学模型 数学模型方法 基本步骤
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热力耦合问题数学均匀化方法的物理意义 被引量:1
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作者 朱晓鹏 黄俊 +1 位作者 陈磊 邢誉峰 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2019年第11期2139-2151,共13页
针对复合材料周期结构热力耦合问题,通过构造各阶摄动项的全解耦格式,推导了高阶数学均匀化方法(MHM)的数学表达式,并使用加权残量方法将其转换为易于编程实现的矩阵列式。将弹性影响函数和热影响函数分别比拟为弹性虚拟位移和热虚拟位... 针对复合材料周期结构热力耦合问题,通过构造各阶摄动项的全解耦格式,推导了高阶数学均匀化方法(MHM)的数学表达式,并使用加权残量方法将其转换为易于编程实现的矩阵列式。将弹性影响函数和热影响函数分别比拟为弹性虚拟位移和热虚拟位移,通过弹性虚拟载荷和热虚拟载荷的自平衡特性、量纲分析及几何直观等角度揭示了各阶影响函数和摄动位移的物理意义,并指出二阶摄动位移对于细观结构分析的必要性。数值计算结果验证了高阶MHM矩阵列式及物理意义分析的正确性。 展开更多
关键词 周期复合材料结构 数学均匀方法(MHM) 热力耦合 摄动位移 物理意义
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热力耦合问题数学均匀化方法的计算精度 被引量:4
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作者 李鸿鹏 凌松 +2 位作者 戚振彪 姜克儒 陈磊 《应用数学和力学》 CSCD 北大核心 2020年第1期54-69,共16页
针对复合材料周期结构热力耦合问题,推导了数学均匀化方法(MHM)各阶摄动位移的全解耦格式和各阶影响函数控制方程,并使用加权残量方法将其转化为易于编程计算的有限元列式.在解耦格式中,各阶摄动位移是相应阶次的影响函数和宏观场导数... 针对复合材料周期结构热力耦合问题,推导了数学均匀化方法(MHM)各阶摄动位移的全解耦格式和各阶影响函数控制方程,并使用加权残量方法将其转化为易于编程计算的有限元列式.在解耦格式中,各阶摄动位移是相应阶次的影响函数和宏观场导数的乘积,即影响函数和宏观场导数的计算精度共同决定摄动项的精度,其中影响函数的计算精度取决于单胞边界条件选取的适用性.针对2D复合材料周期结构静力学问题,使用超单胞边界条件和微分求积有限单元法,分别提高了影响函数和宏观场导数的求解精度.在此基础上,研究了高阶展开项对MHM真实位移精度的影响,确定了二阶摄动项的必要性.最后应用最小势能原理评估了各阶摄动MHM的计算精度,数值比较结果验证了结论的正确性. 展开更多
关键词 数学均匀方法 周期复合材料 热力耦合 高阶摄动
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数学模型化方法:—中学数学现代科学方法
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作者 陈洽材 《钦州师专钦州教院学报》 1995年第4期75-80,共6页
运用数学模型化方法发展发散思想。
关键词 数学模型方法 数学方法 中学 发散思想
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《化学反应工程分析》“后语”(之二)——化学反应工程方法论讲座(第三讲) 被引量:4
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作者 袁渭康 《化工高等教育》 2002年第4期33-36,82,共5页
关键词 学反应工程分析》 方法 高等学校 数学模型方法 模型参数
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化学习题教学中应重视对学生解题方法的指导
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作者 杨鹤鸣 《宁波大学学报(教育科学版)》 2001年第3期144-145,共2页
关键词 解题方法 理想方法 数学化方法 指导 学教学 分科教学法
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新加坡小学数学教材的特色及启示 被引量:8
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作者 张文宇 傅海伦 《数学教育学报》 北大核心 2011年第4期63-66,共4页
新加坡的小学数学教材具有鲜明的特色,如:模型化方法的使用,螺旋式上升的内容编排方式,注重数学活动,注重信息技术和数学课程的整合.这些特色对中国小学数学课程教学研究有重要的启示:重视培养学生的数学问题解决能力;保持传统... 新加坡的小学数学教材具有鲜明的特色,如:模型化方法的使用,螺旋式上升的内容编排方式,注重数学活动,注重信息技术和数学课程的整合.这些特色对中国小学数学课程教学研究有重要的启示:重视培养学生的数学问题解决能力;保持传统优势,发展“双基”教学;重视数学活动的开展. 展开更多
关键词 问题解决 模型方法:数学活动 信息技术
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若干周期性复合材料结构数学均匀化方法的计算精度 被引量:7
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作者 邢誉峰 陈磊 《航空学报》 EI CAS CSCD 北大核心 2015年第5期1520-1529,共10页
数学均匀化方法(MHM)一般需要通过有限元方法(FEM)来实现,摄动阶次和单元阶次直接影响计算结果。在解耦格式中,各阶摄动位移是相应阶次的影响函数和均匀化位移导数的乘积。单元阶次的选取取决于影响函数和均匀化位移的精度要求,而摄动... 数学均匀化方法(MHM)一般需要通过有限元方法(FEM)来实现,摄动阶次和单元阶次直接影响计算结果。在解耦格式中,各阶摄动位移是相应阶次的影响函数和均匀化位移导数的乘积。单元阶次的选取取决于影响函数和均匀化位移的精度要求,而摄动阶次的选取则主要依赖于虚拟载荷的性质和均匀化位移各阶导数的计算精度;针对周期性复合材料杆的静力学问题,在施加不同阶次的载荷时,通过选择合适阶次的单元和摄动阶次得到了精确解。使用类似的方法研究了2D周期性复合材料静力学问题,指出了四边固支作为周期性单胞边界条件以及宏观位移求导精度对计算结果将有很大的影响。强调了二阶摄动对数学均匀化方法计算精度的作用;在数值结果中,应用最小势能原理评估了各阶摄动数学均匀化方法的计算精度,数值比较结果验证了结论的正确性。 展开更多
关键词 周期性复合材料结构 数学均匀方法 摄动阶次 单元阶次 势能泛函
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RESEARCH OF THE PARAMETRIC ASSEMBLY METHOD
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作者 孙知信 陈文亮 +1 位作者 丁秋林 张娟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1997年第2期165-169,共5页
The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly,... The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly, and by compiling operations like movement and rotation, the assembly drawing is created so as to implement the occurrence of the parameterizations of the assembly and the part drawing. The data structure of the assembly part and the key technologies of hidden line removal in the implementation of assembly process, etc. , are described in detail. 展开更多
关键词 ASSEMBLING PARAMETERS product modelling design methodology parametric drawing hidden line removal
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Adsorption of Rhenium(Ⅶ) with Anion Exchange Resin D318 被引量:11
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作者 舒增年 杨明华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第3期372-376,共5页
The adsorption and mechanism of Re(Ⅶ)on resin D318 were studied using chemical methods and IR spectrometry.At pH 5.2,the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg·g-1,respective... The adsorption and mechanism of Re(Ⅶ)on resin D318 were studied using chemical methods and IR spectrometry.At pH 5.2,the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg·g-1,respectively.The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10-4s-1.The desorption percentage was up to 99.7%when 2.0 mol·L-1KSCN was used for dynamic desorption. 展开更多
关键词 RHENIUM resin D318 ADSORPTION DESORPTION
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Chemometrics-aided Metabolic Fingerprint Method Applied in Bladder Cancer Stages Differentiating
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作者 You QIN Lin CHEN +2 位作者 Jian-Hu HUANG Shui-Han ZHANG Zuo-Wei XIAO 《Digital Chinese Medicine》 2018年第3期211-218,共8页
Objective To establish early detection and diagnosis for bladder cancer.Methods In the current study,a metabolomics strategy was used to profile bladder cancer urine metabolites in mice and to further characterize the... Objective To establish early detection and diagnosis for bladder cancer.Methods In the current study,a metabolomics strategy was used to profile bladder cancer urine metabolites in mice and to further characterize the disease status at different stages.In addition,some chemometrics algorithms were adopted to analyze the metabolites fingerprints,including baseline removal and retention time shift,to overcome variations in the experimental process.After processing,metabolites were qualitatively and quantitatively analyzed in each sample at different stages.Finally,a random forest algorithm was used to discriminate the differences among different groups.Results Four potential biomarkers,including glyceric acid,(R*,R*)-2,3-Dihydroxybutanoic acid,N-(1-oxohexyl)-glycine and D-Turanose,were discovered by exploring the characteristics of different groups.Conclusion These results suggest that combining chemometrics with the metabolites profile is an effective approach to aid in clinical diagnosis. 展开更多
关键词 Metabolic fingerprints Chemometrics approaches Data analysis Bladder cancer
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Spin Transport in a Rashba Ring-Quantum Dot System Pumped by Microwave Fields
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作者 张林 汪军 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期709-714,共6页
We report a theoretical study on producing electrically spin-polarized current in the Rashba ring with parallel double dots embedded, which are subject to two time-dependent microwave fields. By means of the Keldysh G... We report a theoretical study on producing electrically spin-polarized current in the Rashba ring with parallel double dots embedded, which are subject to two time-dependent microwave fields. By means of the Keldysh Green's function method, we present an analytic result of the pumped current at adiabatic limit and demonstrate that the interplay between the quantum pumping effect and spin-dependent quantum interference can lead to an arbitrarily controllable spin-polarized current in the device. The magnitude and direction of the charge and spin current can be effectively modulated by system parameters such as the pumping phase difference, Rashba precession phase, and the dynamic phase difference of electron traveling in two arms of ring; moreover, the spin-polarization degree of the charge current can also be tuned in the range [-∞, +∞]. Our findings may shed light on the all-electric way to produce the controllable spin-polarized charge current in the field of spintronics. 展开更多
关键词 spin-polarized current Rashba spin-orbit coupling microwave field Keldysh Green's function
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Enhancing pose accuracy of space robot by improved differential evolution
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作者 刘宇 倪风雷 +1 位作者 刘宏 徐文福 《Journal of Central South University》 SCIE EI CAS 2012年第4期933-943,共11页
Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the ... Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the real pose (including position and orientation) of the end effector not to match the desired one, and further hinder the space robot from performing the scheduled mission. To improve pose accuracy of space robot, a new self-calibration method using the distance measurement provided by a laser-ranger fixed on the end-effector is proposed. A distance-measurement model of the space robot is built according to the distance from the starting point of the laser beam to the intersection point at the declining plane. Based on the model, the cost function about the pose error is derived. The kinematic calibration is transferred to a non-linear system optimization problem, which is solved by the improved differential evolution (DE) algoritlun. A six-degree of freedom (6-DOF) robot is used as a practical simulation example, and the simulation results show: 1) A significant improvement of pose accuracy of space robot can be obtained by distance measurement only; 2) Search efficiency is increased by improved DE; 3) More calibration configurations may make calibration results better. 展开更多
关键词 space robot SELF-CALIBRATION laser ranger pose accuracy improved differential evolution
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Entropy Production along Dominant Pathway of Nonequilibrium Phase Transition in Mesoscopic Chemical System
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作者 Han-shuang Chen Gang He +1 位作者 Feng Huang Chuan-sheng Shen 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第5期549-552,I0003,共5页
We consider a bistable mesoscopic chemical reaction system and calculate entropy produc- tion along the dominant pathway during nonequilibrium phase transition. Using probability generating function method and eikonal... We consider a bistable mesoscopic chemical reaction system and calculate entropy produc- tion along the dominant pathway during nonequilibrium phase transition. Using probability generating function method and eikonal approximation, we first convert the chemical master equation into the classical Hamilton-Jacobi equation, and then find the dominant pathways between two steady states in the phase space by calculating zero-energy trajectories. We find that entropy productions are related to the actions of the forward and backward dominant pathways. At the coexistence point where the stabilities of the two steady states are equiv alent, both the system entropy change and the medium entropy change are zero; whereas at non-coexistence point both of them are nonzero. 展开更多
关键词 Entropy production Mesoscopic chemical reaction Nonequilibrium phasetransition
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Genesis and Quality of Groundwater in the Southeastern Region of Southern Vietnam
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作者 Chau Tran Vinh Tran Hong Thai +5 位作者 Doan Van Canh Dang Due Nhan Nguyen Cao Huan Nguyen Van Nghia Nguyen Hong Hieu Trinh Thi Thu Van 《Journal of Environmental Science and Engineering(A)》 2017年第6期277-292,共16页
The origin and quality of groundwater in the Southeastern region (belongs to Southern Plain) were identified by using isotopic techniques and geochemical analysis. Groundwater samples were collected from 7 aquifers... The origin and quality of groundwater in the Southeastern region (belongs to Southern Plain) were identified by using isotopic techniques and geochemical analysis. Groundwater samples were collected from 7 aquifers: the Holocene, upper Pleistocene, middle Pleistocene, lower Pleistocene, upper Pliocene, middle Pliocene and Miocene aquifers. The water isotopic compositions (82H and 8180) were determined to elucidate the origin and the interaction between surface water and groundwater studies. Transit time (age) of the groundwater samples was determined to explain the direction of groundwater flow. The dating techniques included 3H and ^14C isotopes measurement, followed by a correction for the initial ^14C-activity by the ^13C-composition (^13C) in TDIC (Total Dissolved Inorganic Carbon). Geochemical parameters of the groundwater samples were measured either directly in the field or in the laboratory. The results showed that the groundwater from the Holocene and upper Pleistocene aquifers was most recharged from the local meteorological and hydrological systems, including local precipitation, fiver and reservoirs. Thus, it has short transit time and its stable isotopic composition is spread around the local meteoric waterline and lines for rivers or reservoirs water. The groundwater in the deeper aquifers: middle and lower Pleistocene, and Neogene aquifers has old age up to 22.5 ka BP. Its water seems to be recharged from the areas with an altitude from 600 to 700 m higher to the Neogene deposit layer altitude. The groundwater in the SE SP (South-Eastern Southern Plain) region has a high quality. The water type is Na-Ca-Mg-HCO3 with low content of chloride and TDS (Total Dissolved Solids). Calcite/dolomite and gypsum dissolution, organic matter decomposition and sequence of red-ox reactions proceeding through different electron acceptors sediment were controlled the chemistry of the groundwater in the study region. 展开更多
关键词 Water isotopic composition ^14C-dating GROUNDWATER South-Eastern Southern Plain region Vietnam.
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建立机关后勤工作量化指标评价体系
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作者 姚万垠 《中国机关后勤》 2001年第6期26-28,共3页
关键词 机关后勤工作 指标 测评体系 工作目标 科学管理 经济指标 指标评价体系 质量标准 数学化方法 现代企业制度
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新教材中在《等比数列求和》教学中培养学生数学素养
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作者 徐洁 《进展》 2023年第16期183-185,共3页
在高中数学教学中,利用教材培养学生初步综合运用观察、分析、归纳、猜想、证明、数学建模等方法及应用能力,突出学生的数据处理、转化化归、代数推理和数学思想方法的提炼和运用能力。高中数学教师要善于利用多媒体优化知识教学,丰富... 在高中数学教学中,利用教材培养学生初步综合运用观察、分析、归纳、猜想、证明、数学建模等方法及应用能力,突出学生的数据处理、转化化归、代数推理和数学思想方法的提炼和运用能力。高中数学教师要善于利用多媒体优化知识教学,丰富学生之间的合作交流,展开多样化的实践探究活动,加强学生解题能力培养锻炼。 展开更多
关键词 数据处理 归代数推理数学思想方法的提炼和运用
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A Class of Smoothing-regularization Methods to Mathematical Programs with Vanishing Constraints
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作者 HU Qingjie MA Lili CHEN Yu 《数学进展》 CSCD 北大核心 2024年第5期953-973,共21页
this paper,we propose a class of smoothing-regularization methods for solving the mathematical programming with vanishing constraints.These methods include the smoothing-regularization method proposed by Kanzow et al.... this paper,we propose a class of smoothing-regularization methods for solving the mathematical programming with vanishing constraints.These methods include the smoothing-regularization method proposed by Kanzow et al.in[Comput.Optim.Appl.,2013,55(3):733-767]as a special case.Under the weaker conditions than the ones that have been used by Kanzow et al.in 2013,we prove that the Mangasarian-Fromovitz constraint qualification holds at the feasible points of smoothing-regularization problem.We also analyze that the convergence behavior of the proposed smoothing-regularization method under mild conditions,i.e.,any accumulation point of the stationary point sequence for the smoothing-regularization problem is a strong stationary point.Finally,numerical experiments are given to show the efficiency of the proposed methods. 展开更多
关键词 mathematical programs with vanishing constraints smoothing-regularization method VC-MFCQ strong stationary point
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