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Numerical simulation of non-Archie electrophysical property of saturated rock with lattice Boltzmann method 被引量:2
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作者 Yue Wenzheng Tao Guo +1 位作者 Liu Dongming Yang Wendu 《Petroleum Science》 SCIE CAS CSCD 2009年第1期24-28,共5页
The electrophysical property of saturated rocks is very important for reservoir identification and evaluation. In this paper, the lattice Boltzmann method (LBM) was used to study the electrophysical property of rock... The electrophysical property of saturated rocks is very important for reservoir identification and evaluation. In this paper, the lattice Boltzmann method (LBM) was used to study the electrophysical property of rock saturated with fluid because of its advantages over conventional numerical approaches in handling complex pore geometry and boundary conditions. The digital core model was constructed through the accumulation of matrix grains based on their radius distribution obtained by the measurements of core samples. The flow of electrical current through the core model saturated with oil and water was simulated on the mesoscopic scale to reveal the non-Archie relationship between resistivity index and water saturation (I-Sw). The results from LBM simulation and laboratory measurements demonstrated that the I-Sw relation in the range of low water saturation was generally not a straight line in the log-log coordinates as described by the Archie equation. We thus developed a new equation based on numerical simulation and physical experiments. This new equation was used to fit the data from laboratory core measurements and previously published data. Determination of fluid saturation and reservoir evaluation could be significantly improved by using the new equation. 展开更多
关键词 Non-Archie relation digital core model lattice Boltzmann method numerical simulation rock physical experiment
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A Physical Method of Analyzing theMechanism of Continental StrongShocks from Crustal Movement 被引量:4
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作者 Shen Chongyang,Wu Yun,and Gan Jiasi Institute of Seismology. CSB, Wuhan 430071,China 《Earthquake Research in China》 2001年第3期282-297,共16页
In order to analyze the mechanism of continental strong shocks from the angle of crustal movement using the data of repeated geodetic survey, this paper has proposed a physical method; it analyzes the mechanism of den... In order to analyze the mechanism of continental strong shocks from the angle of crustal movement using the data of repeated geodetic survey, this paper has proposed a physical method; it analyzes the mechanism of density change due to the occurrence of strong shocks by use of the physical quantity that reflects the time change of crustal density. (1) The general theory of the time change of density in the earth’ s interior and the theory of the time change of single layer density have been introduced, and an algorithm of stepwise iteration has been proposed; (2) The effect of the change of single layer density caused by fault dislocation has been analyzed in brief; (3) The characteristics of the time change of crustal density in the south of the seismogenic region before the 1996 Lijiang earthquake with M_L =7.0 have been studied; (4) The precursor model or causal mechanism of strong shocks possibly existing in the time change of crustal density has been investigated preliminarily. 展开更多
关键词 CRUSTAL MOVEMENT Mechanism of STRONG SHOCKS Density change physical method
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A simple physical mixing method for MnO2/MnO nanocomposites with superior Zn^2+storage performance 被引量:3
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作者 Xiao-bei ZANG Ling-tong LI +5 位作者 Zhi-xin SUN Rabah BOUKHERROUB Jia-xin MENG Kun-peng CAI Qing-guo SHAO Ning CAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第12期3347-3355,共9页
MnO2/MnO cathode material with superior Zn^2+storage performance is prepared through a simple physical mixing method.The MnO2/MnO nanocomposite with a mixed mass ratio of 12:1 exhibits the highest specific capacity(36... MnO2/MnO cathode material with superior Zn^2+storage performance is prepared through a simple physical mixing method.The MnO2/MnO nanocomposite with a mixed mass ratio of 12:1 exhibits the highest specific capacity(364.2 mA·h/g at 0.2C),good cycle performance(170.4 mA·h/g after 100 cycles)and excellent rate performance(205.7 mA·h/g at 2C).Analysis of cyclic voltammetry(CV)data at various scan rates shows that both diffusioncontrolled insertion behavior and surface capacitive behavior contribute to the Zn2+storage performance of MnO2/MnO cathodes.And the capacitive behavior contributes more at high discharge rates,due to the short paths of ion diffusion and the rapid transfer of electrons. 展开更多
关键词 zinc-ion battery MnO2/MnO cathode material physical mixing method reaction kinetics
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Physical Parameter Identification Method Based on Modal Analysis for Two-axis On-road Vehicles:Theory and Simulation 被引量:3
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作者 ZHENG Minyi ZHANG Bangji +1 位作者 ZHANG Jie ZHANG Nong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期756-764,共9页
Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unkno... Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unknown parameters can be identified.In order to identify physical parameters of vehicle in the case that all physical parameters are unknown,a methodology based on the State Variable Method(SVM) for physical parameter identification of two-axis on-road vehicle is presented.The modal parameters of the vehicle are identified by the SVM,furthermore,the physical parameters of the vehicle are estimated by least squares method.In numerical simulations,physical parameters of Ford Granada are chosen as parameters of vehicle model,and half-sine bump function is chosen to simulate tire stimulated by impulse excitation.The first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%;and the effect of the errors of additional mass,structural parameter and measurement noise are discussed in the following simulations,the results shows that when signal contains 30 d B noise,the largest absolute value of percentage error of the identification is 3.78%.These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road vehicles.The proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known. 展开更多
关键词 Parameter identification free-decay response state variable method modal parameter physical parameter
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Factors Related to Engaging in Physical Activity: A Mixed Methods Study of Female University Students 被引量:1
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作者 Afnan H. Saaty Debra B. Reed +1 位作者 Weiwu Zhang Mallory Boylan 《Open Journal of Preventive Medicine》 2015年第10期416-425,共10页
Objective: As a needs assessment for intervention, quantitative and qualitative methods were used to examine attitude, subjective norms, perceived behavioral control, intention, knowledge, and weight control status re... Objective: As a needs assessment for intervention, quantitative and qualitative methods were used to examine attitude, subjective norms, perceived behavioral control, intention, knowledge, and weight control status related to physical activity in female university students within the Theory of Planned Behavior (TPB). Methods: A two-phase mixed method design was used. In Phase I, 362 students participated in an online survey, and in Phase II, 33 students participated in five focus group discussions. Ages of participants ranged from 18 to 45 years old, with 18 - 25 year olds making up over 74% of the sample. Results: Attitude, subjective norms, and perceived behavioral control, along with weight control status of trying to lose weight, were found to be significant predictors of intention to follow physical activity recommendations, which in turn were the strongest predictor of physical activity. Knowledge was not found to be significant. Group discussions revealed barriers to meeting physical activity recommendations, which included lack of companionship and social support, lack of motivation, time and cost restrictions, and lack of privacy in the gym. Social norms exerted both positive and negative influences. Conclusion: The mixed method approach provided a deeper insight into the influential factors pertaining to physical activity among female students, and results could be used in further research to develop effective interventions. 展开更多
关键词 physical Activity Theory of PLANNED Behavior FEMALE UNIVERSITY STUDENTS Mixed methods
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Improvements of marine clay slurries using chemicale-physical combined method(CPCM) 被引量:1
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作者 Dongqing Wu Wenyu Xu Romy Tjuar 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第2期220-225,共6页
In this paper, the effectiveness, applicability and validity of chemicalephysical combined methods(CPCMs) for treatment of marine clay (MC) slurries were evaluated. The method CPCM1 combineschemical stabilization ... In this paper, the effectiveness, applicability and validity of chemicalephysical combined methods(CPCMs) for treatment of marine clay (MC) slurries were evaluated. The method CPCM1 combineschemical stabilization and vacuum preloading (VP), while CPCM2 is similar to CPCM1 but includes boththe application of surcharge and use of geo-bags to provide confinement during surcharge preloading.The key advantage of CPCM2 using geo-bags is that the surcharge can be immediately applied on thechemically stabilized slurries. Two types of geo-bags were investigated under simulated land filling anddyke conditions, respectively. The test results show that the shear strength (cu) of treated slurry byCPCM2 is generally much higher than that by CPCM1. Besides, the use of CPCM2 can significantly reducethe treatment time due to the short drainage paths created by geo-bags. Overall, CPCM2 allows fasterconsolidation and higher preloading that help to achieve higher mechanical properties of the stabilizedslurry. There are consistent relationships between cU and water content of slurries treated by CPCM2.Several important observations were also made based on comparisons of experimental data. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved. 展开更多
关键词 Chemical e physical combined method(CPCM) Soil improvement Marine clay(MC) slurry Land reclamation Chemical stabilization Vacuum preloading(VP) Geo-bags SURCHARGE
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Effects of Varieties and Cooking Methods on Physical and Chemical Characteristics of Cooked Rice 被引量:1
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作者 Merynda Indriyani SYAFUTRI Filli PRATAMA +1 位作者 Friska SYAIFUL Achmad FAIZAL 《Rice science》 SCIE CSCD 2016年第5期282-286,共5页
To analyze the effect of different lowland rice varieties and different cooking methods on physical and chemical characteristics of cooked rice. A factorial randomized block design with two factors was used and each c... To analyze the effect of different lowland rice varieties and different cooking methods on physical and chemical characteristics of cooked rice. A factorial randomized block design with two factors was used and each combination of the factors was repeated three times. The first factor was rice variety(Ciherang and Ciliwung) and the second factor was the cooking method(stovetop, boiling and steaming, and rice cooker). Results showed that Ciherang and Ciliwung varieties were classified into slender grain rice type with yellowred color. The amylose content of Ciherang was classified as moderate, while the amylose content of Ciliwung classified as low. The most abundant amino acid contained in Ciherang and Ciliwung varieties was glutamic acid. Statistical analysis showed that cooking method had significant effects on texture, lightness, chroma, hue and moisture content of cooked rice. Rice cooked with liwet method had the lowest texture value, lowest lightness value, highest chroma value, and highest moisture content. 展开更多
关键词 physical and chemical characteristic cooking method rice variety amino acid
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Adolescents’ perspectives on a school-based physical activity intervention:A mixed method study
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作者 Stephanie T.Jong Caroline H.D.Croxson +8 位作者 Cornelia Guell Emma R.Lawlor Campbell Foubister Helen E.Brown Emma K.Wells Paul Wilkinson Anna Vignoles Esther M.F.van Sluijs Kirsten Corder 《Journal of Sport and Health Science》 SCIE 2020年第1期28-40,F0003,共14页
Purpose'. To examine adolescent experiences and perspectives of the GoActive intervention (ISRCTN31583496) using mixed methods processevaluation to determine satisfaction with intervention components and interpret... Purpose'. To examine adolescent experiences and perspectives of the GoActive intervention (ISRCTN31583496) using mixed methods processevaluation to determine satisfaction with intervention components and interpret a*dolescents experiences of the intervention process in order toprovide insights for future intervention design.Methods'. Participants (n = 1542;13.2 土 0.4 years, mean 土 SD) provided questionnaire data at baseline (shyness, activity level) and post-intervention(intervention acceptability, satisfaction with components). Between-group differences (boys vs. girls and shy/inactive vs. others) weretested with linear regression models, accounting for school clustering. Data from 16 individual interviews (shy/inactive) and 11 focus groupswith 48 participants (mean = 4;range 2—7) were thematically coded. Qualitative and quantitative data were merged in an integrative mixedmethods convergence matrix, which denoted convergence and dissonance across datasets.Results'. Effect sizes for quantitative results were small and may not represent substantial between-group differences. Boys (vs. girls) preferredclass-based sessions (0 = 0.2, 95% confidence interval (CI): 0.1—0.3);qualitative data suggested that this was because boys preferred competition,which was supported quantitatively (0 = 0.2, 95%CI: 0.1-0.3). Shy/inactive students did not enjoy the competition (0 = -0.3, 95%CI:—0.5 to —0.1). Boys enjoyed trying new activities more (0 = 0.1, 95%CI: 0.1 -0.2);qualitative data indicated a desire to try new activities acrossall subgroups but identified barriers to choosing unfamiliar activities with self-imposed choice restriction leading to boredom. Qualitative datahighlighted critique of mentorship;adolescents liked the idea, but older mentors did not meet expectations.Conclusion. We interpreted adolescent perspectives of intervention components and implementation to provide insights into future complexinterventions aimed at increasing young people's physical activity in school-based settings. The intervention component mentorship was liked inprinciple, but implementation issues undesirably impacted satisfaction;competition was disliked by girls and shy/inactive students. The resultshighlight the importance of considering gender differences in preference of competition and extensive mentorship training. 展开更多
关键词 ADOLESCENT INTERVENTION Mixed methods physical activity Process evaluation
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STUDY OF NUMERICAL AND PHYSICAL FRACTURE WITH SPH METHOD
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作者 Fei Xu Yah Zhao +1 位作者 Yulong Li Masanori Kikuchi 《Acta Mechanica Solida Sinica》 SCIE EI 2010年第1期49-56,共8页
Two kinds of fractures can be observed in the SPH (smoothed particle hydrodynamics) simulations, which are the physical fracture and the numerical fracture. The physical one exists in reality, while the numerical on... Two kinds of fractures can be observed in the SPH (smoothed particle hydrodynamics) simulations, which are the physical fracture and the numerical fracture. The physical one exists in reality, while the numerical one is fictitious. This paper presents the effects of both fractures and proposes a simple adding particle technique to avoid the numerical fracture. The real physical fracture is then figured out by using an applicable fracture criterion. Firstly, the effect of the numerical fracture on the computational accuracy is investigated by introducing the artificial fracture in a model of wave propagation. Secondly, a simple adding particle technique is proposed and validated by a three dimensional bending test. Finally, the experiments of penetration on the skin of aircrafts are simulated by both the initial SPH method and the improved method with the adding particle technique. The results show that the improved SPH method can describe the physical fracture very well with better accuracy. 展开更多
关键词 SPH method physical fracture numerical fracture adding particle technique
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MEASUREMENT METHOD AND PHYSICAL MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS
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作者 万梅香 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第4期330-339,共10页
Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC... Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail. 展开更多
关键词 VSC show MEASUREMENT method AND physical MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS
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Growth and Physical Properties of CdS/TiO_2 Bilayer by Plasma-Based Method
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作者 T.Hoseinzadeh M.Ghoranneviss +1 位作者 E.Akbarnejad Z.Ghorannevis 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第3期39-42,共4页
The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2... The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2 nanotubes arrays by radio-frequency magnetron sputtering. X-ray diffraction, scanning electron mieroscopy, transmission electron microscopy and diffuse reflection spectra are used to study structural, morphological and optical properties of the CdS/TiO2 bilayer. 展开更多
关键词 CDS TIO Growth and physical Properties of CdS/TiO2 Bilayer by Plasma-Based method
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Studies of Atomic Structure and Physical Properties of Metal Clusters in MgO by HREM and Nano-probe Methods
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作者 Nobuo Tanaka (Dept. of Applied Physics, School of Engineering, Nagoya University, Nagoya, 464-01, Japan) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1997年第4期265-270,共6页
Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area el... Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area electron diffraction. The size of the clusters is ranging from 1 nm to 3 nm without those larger than 5 nm, and most of them have definite epitaxial orientations with the MgO matrix films. The character of the composite films is very much useful for the studies of various kinds of physical properties with anisotroPy. The physical properties such as electric transport, magnetic, optical absorption, sintering and catalytic ones were thus measured on the same samples analyzed by HREM by using high sensitivity apparatus with interest of clarifying the retationship between the atomic structure and physical properties 展开更多
关键词 FIGURE NANO Studies of Atomic Structure and physical Properties of Metal Clusters in MgO by HREM and Nano-probe methods HREM MGO
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Hydrodynamic Performance of a Newly-Designed Pelagic and Demersal Trawls Using Physical Modeling and Analytical Methods for Cameroonian Industrial Fisheries
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作者 Tcham Leopold Vanlie Maurice Kontchou +2 位作者 Nyatchouba Nsangue Bruno Thierry Abdou Njifenjou Njomoue Pandong Achille 《Open Journal of Marine Science》 2023年第3期41-65,共25页
This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were inve... This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were investigated using physical modelling method and analytical method based on the predicted equations. In a flume tank, a series of physical model tests based on Tauti’s law were performed to investigate the hydrodynamic and geometrical performances of both trawls and to assess the applicability of the analytical methods based on predicted equations. The results showed that in model scale, the working towing speed and door spread for the pelagic trawl were 3.5 knots and 1.85 m, respectively, and for the bottom trawl net they were 4.0 knots and 1.8 m. At that speed and door spread, the drag force, net opening height, and wing-end spread of the pelagic model trawl were 36.73 N, 0.89 m, and 0.86 m, respectively, and the swept area was 0.76 m<sup>2</sup>. Bottom trawl speed and door spread were 30.43 N, 0.38 m, and 0.45 m, respectively, and the swept area was 0.25 m<sup>2</sup>. The maximum difference between the experimental and analytical results of hydrodynamic performances was less than 56.22% and 41.45%, respectively, for pelagic and bottom trawls, the results of the geometrical performances obtained using predicted equations were close to the experimental results in the flume tank with a maximum relative error less than 12.85%. The newly developed pelagic and bottom trawls had advanced engineering performance for high catch efficiency and selectivity and could be used in commercial fishing operations in Cameroonian waters. 展开更多
关键词 Cameroonian Waters Pelagic Trawl Bottom Trawl Engineering Performances physical Model Test Analytical methods Formatting
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Study and Practice of "Harmonious Teaching Method" in Art Course Teaching of College Physical Education Taking College Sports Dance Teaching As an Example
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作者 Long WU 《International English Education Research》 2014年第2期112-115,共4页
The ultimate goal of college personnel training is "comprehensively implementing quality-oriented education and cultivating innovation-oriented personnel". The application of "harmonious teaching method" in the sp... The ultimate goal of college personnel training is "comprehensively implementing quality-oriented education and cultivating innovation-oriented personnel". The application of "harmonious teaching method" in the sports dance teaching of general colleges can help theoretically analyze the teaching process of existing sports dance actions and reveal the main reason for the gap with the goal of "comprehensive harmonious development", and also can verify the theoretical analysis results. Therefore, using teaching experiment method, experiment class and control class were selected for implementing two different teaching methods. Difference T test of small samples average was made on the acquired data for revealing the teaching effect difference between two different teaching methods. The result shows that the difference between two teaching methods was significant. The application of "harmonious teaching method" in the sports dance teaching of physical education of general colleges plays a certain positive role in training the comprehensive and harmonious moral, intellectual and physical developments of college students. 展开更多
关键词 COLLEGES physical Education Harmonious Teaching method STUDY
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Discussion on incentives of Physical Education Teaching Methods
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作者 Hongtao PAN 《International Journal of Technology Management》 2015年第7期140-142,共3页
The use of literature, logical reasoning and other research methods are used in this thesis, classification and analysis of the definition of incentive methods, motivation methods are also stated in this paper, and th... The use of literature, logical reasoning and other research methods are used in this thesis, classification and analysis of the definition of incentive methods, motivation methods are also stated in this paper, and this article also combine with students' psychological characteristics, different teaching content, teaching methods together, discussed how to stimulate students' interest in sports and mobilize students' enthusiasm, initiative by motivation methods in the sports teaching, thus promoting teaching effectiveness, improve teaching quality, provide some theoretical reference for improving the quality of teaching physical education. The results showed that: we have already made some researches in the stimulation methods in teaching sports, but few are studied combining with the psychological characteristics of students 展开更多
关键词 physical education motivation methods SECONDARY
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Perturbation-Iteration Method for Solving Mathematical Model of Glucose and Insulin in Diabetic Human during Physical Activity
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作者 Marcel Gahamanyi Jean Marie Ntaganda Mahamat Saleh Daoussa Haggar 《Open Journal of Applied Sciences》 2016年第12期826-838,共14页
In this paper, we aim to solve a two compartmental mathematical model of ordinary differential equations for cardiovascular-respiratory system using a new recent method: Perturbation Iteration method. The description ... In this paper, we aim to solve a two compartmental mathematical model of ordinary differential equations for cardiovascular-respiratory system using a new recent method: Perturbation Iteration method. The description of this method for different order derivatives in the Taylor Series expansion is discussed. This method provides the solution in the form of an infinite series for ordinary differential equation. The efficiency of the method used is investigated by a comparison of Euler method and Runge Kutta. Numerical simulations of all these three methods are implemented in Matlab. The validation has been carried out by taking the values of determinant parameters of cardiovascular-respiratory system for a 30 years old woman who is supposed to make practice of three regular physical activities: Walking, Jogging and Running fast. The results are in good agreement with experimental data. 展开更多
关键词 Perturbation-Iteration method GLUCOSE INSULIN Heart Rate Alveolar Ventilation physical Activity Numerical Simulation
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Exploration and safety evaluation on Panzhihua iron barren rock with physical geographical methods
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作者 Xianguo TUO Wan LEI +2 位作者 Zhengqi XU Jinxi LI Keliang MU 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期37-37,共1页
关键词 物理地质勘探 地震 高密度电法 精密度 岩石
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FREE VIBRATION ANALYSIS AND PHYSICAL PARAMETER IDENTIFICATION OF NON-UNIFORM BEAM CARRYING SPRING-MASS SYSTEMS 被引量:1
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作者 马蕾 芮筱亭 +2 位作者 Abbas Laith 杨富锋 张建书 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第4期345-353,共9页
To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is dev... To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system(MS-TMM), the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method (NAM), the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms(GAs) are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach. 展开更多
关键词 non-uniform beam physical parameter identification natural frequency transfer matrix method multibody system genetic algorithms
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Relationship between Rock Fracture Toughness and Physical Properties 被引量:1
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作者 Zhao Zhenfeng Chen Mian 《Petroleum Science》 SCIE CAS CSCD 2006年第1期56-60,共5页
The relationship between shale toughness and its mechanical parameters is of significance for predicting the shale toughness at a great depth based on the geophysical logging data. A large amount of experiments is per... The relationship between shale toughness and its mechanical parameters is of significance for predicting the shale toughness at a great depth based on the geophysical logging data. A large amount of experiments is performed for toughness measurement of the artificial shale specimens of thick-wall cylinder, with internal pressures applied. Moreover, the finite element method is used to interpret the toughness. The acoustic speeds of the specimens are measured and the relationships between shale toughness and the mechanical parameters, which are almost linear, are established. 展开更多
关键词 Rock toughness physical properties finite element method mechanical
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Medium Access Control: A Physical Layer Network- Coded Approach 被引量:2
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作者 ZHANG Yu XIONG Ke DU Liping 《China Communications》 SCIE CSCD 2014年第A02期1-11,共11页
This paper investigates the medium access control (MAC) stratifies for communication systems. Since the signals are naturally superposed in public medium, we introduce physical layer network coding into MAC system a... This paper investigates the medium access control (MAC) stratifies for communication systems. Since the signals are naturally superposed in public medium, we introduce physical layer network coding into MAC system and propose the physical layer network coded MAC (PNC-MAC) to utilize the collisions occurring in the MAC process. The implicit expressions of the throughput and average delay of the system operated with the new algorithm are derived in an iterative way. To show the performance of the algorithm, we compare the throughput and average delay induced by the new algorithm with current schemes via simulations. The results show that when operated with our proposed PNC-MAC, MAC system can achieve a larger throughput while the frames bear shorter average delay. Moreover, in many users case, the throughput increases slightly while the average delay ascends drastically. 展开更多
关键词 medium access control physical layernetwork coding tree method
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