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A Mixed-Variable Experimental Design Method
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作者 Zili Wan Qi Wang 《Open Journal of Applied Sciences》 2024年第2期343-352,共10页
Mixed-variable problems are inevitable in engineering. However, few researches pay attention to discrete variables. This paper proposed a mixed-variable experimental design method (ODCD): first, the design variables w... Mixed-variable problems are inevitable in engineering. However, few researches pay attention to discrete variables. This paper proposed a mixed-variable experimental design method (ODCD): first, the design variables were divided into discrete variables and continuous variables;then, the DVD method was employed for handling discrete variables, the LHD method was applied for continuous variables, and finally, a Columnwise-Pairwise Algorithm was used for the overall optimization of the design matrix. Experimental results demonstrated that the ODCD method outperforms in terms of the sample space coverage performance. 展开更多
关键词 OPTIMIZATION experimental Design methods Discrete Variable
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Experience and Methods for Maize Regional Experiment in Guizhou Mountainous Areas 被引量:1
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作者 周国富 王国忠 陈恩瑞 《Agricultural Science & Technology》 CAS 2016年第2期347-348,416,共3页
Maize regional experiment is a an intermediate link for overall assessment and comprehensive evaluation on yielding ability, stable yield, stress, adaptability, and quality traits of new maize varieties in different e... Maize regional experiment is a an intermediate link for overall assessment and comprehensive evaluation on yielding ability, stable yield, stress, adaptability, and quality traits of new maize varieties in different ecological conditions. It is an essential process for determining whether the new maize varieties can pass the ex- amination and approval for extension. Besides, regional experiment is an important link connecting agricultural scientific researches and agricultural production. In addi- tion, it is a scientific basis for extension and application of new maize varieties in a region. Therefore, the maize regional experiment is of the utmost importance. 展开更多
关键词 Maize regional experiment Guizhou mountainous areas Experience and methods
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Diversified Teaching Methods in Nursing:Using Animal Experimentation to Promote Core Professional Competencies in Basic Nursing Training 被引量:1
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作者 Hui Lin Wei Wang Yin-Jun Ye 《Chinese Nursing Research》 CAS 2015年第4期155-159,共5页
Objective: The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection an... Objective: The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection and IV infusion in animal experimentation to hone the core professional nursing competencies. Methods: Two classes from the 2012 senior graduating nursing class were randomly selected by a computer to conduct the diversified practical teaching methods based on animal experimentation. A hospital environment was simulated by requiring students to perform different types of injections and practical IV infusion techniques. A comprehensive evaluation of the core professional competencies, as well as other integrated competencies, was conducted to determine the effectiveness of the teaching methods. Results: Two-sampled, pairwise u-tests were performed between the scores of the experimental (nursing class 2) and control (nursing class 1) groups. These findings showed that the overall test scores were significantly higher in the experimental group compared to the control group and that the average P-values for the competencies in various categories were 〈0.01, which indicated statistically significant results. Conclusions: Based on the data from this project, diversified teaching methods for basic nursing training founded on animal experimentation can help nursing students perfect their core professional competencies and improve their overall professional standing. The introduction of animal experimentation requires further verification, and an increased acknowledgement of its benefits through the widespread dissemination of this information. 展开更多
关键词 Core professional competencies Basic nursing experimentation on animals Diversified teaching methods
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Numerical Simulation and Experiment on Dam Break Problem 被引量:6
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作者 胡长洪 末吉诚 《Journal of Marine Science and Application》 2010年第2期109-114,共6页
In this paper, two novel numerical computation methods are introduced which have been recently developed at Research Institute for Applied Mechanics ( R/AM ), Kyushu University, for strongly nonlinear wave-body inte... In this paper, two novel numerical computation methods are introduced which have been recently developed at Research Institute for Applied Mechanics ( R/AM ), Kyushu University, for strongly nonlinear wave-body interaction problems, such as ship motions in rough seas and resulting green-water impact on deck. The first method is the CIP-based Cartesian grid method, in which the free surface flow is treated as a multi-phase flow which is solved using a Cartesian grid. The second method is the MPS method, which is a so-called particle method and hence no grid is used. The features and calculation procedures of these numerical methods are described. One validation computation against a newly conducted experiment on a dam break problem, which is also described in this paper, is presented. 展开更多
关键词 CIP method MPS method darn break experiment
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Finite Element Simulation of Flexible Roll Forming with Supplemented Material Data and the Experimental Verification 被引量:8
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作者 YAN Yu WANG Haibo +1 位作者 LI Qiang GUAN Yanzhi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第2期342-350,共9页
Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform d... Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved. 展开更多
关键词 3D Flexible roll forming constitutive model material data supplementation finite element method experiment verification
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Numerical and experimental studies on impact dynamics of a planar flexible multibody system 被引量:8
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作者 Fu-Xiang Dong Jia-Zhen Hong Kun Zhu Zheng-Yue Yu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第4期635-642,共8页
In this paper a computational methodology on impact dynamics of the flexible multibody system is presented. First, the floating frame of reference approach and nodal coordinates on the basis of finite element formulat... In this paper a computational methodology on impact dynamics of the flexible multibody system is presented. First, the floating frame of reference approach and nodal coordinates on the basis of finite element formulation are used to describe the kinematics of planar deformable bodies. According to the kinematic description of contact conditions, the contact constraint equations of planar flexible bodies are derived. Based on the varying topology technique the impact dynamic equations for a planar multibody system are established. Then the initial conditions of the equations in each contact stage are determined according to the discontinuity theory in continuum mechanics. The experiments between the aluminum rods are performed to check the correctness of the proposed method. Through the comparison between the numerical and experimental results the proposed method is validated. Experimental results also show that the impulse momentum method cannot accurately predict the complex impact dynamic phenomena and the continuous model may lead to a serious error when used to simulate the impact problems with significant wave propagation effects. 展开更多
关键词 Flexible multibody system Impact dynamics Appending constraint method (ACM) Impact experiments
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VIRTUAL EXPERIMENTAL ANALYSIS ON CLEANING ELEMENT OF SUGARCANE HARVESTER 被引量:2
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作者 Ma Fanglan Li Shangping +2 位作者 He Yulin Meng Yanmei Chen Weixu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第4期586-591,共6页
The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of or... The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis (FEA) software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received fiom the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing. 展开更多
关键词 Sugarcane harvester Cleaning element Nonlinear analysis Orthogonal experiment Overall balancing method
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Protein-protein interactions: Methods, databases, and applications in virus-host study 被引量:3
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作者 Qurat ul Ain Farooq Zeeshan Shaukat +1 位作者 Sara Aiman Chun-Hua Li 《World Journal of Virology》 2021年第6期288-300,共13页
Almost all the cellular processes in a living system are controlled by proteins:They regulate gene expression,catalyze chemical reactions,transport small molecules across membranes,and transmit signal across membranes... Almost all the cellular processes in a living system are controlled by proteins:They regulate gene expression,catalyze chemical reactions,transport small molecules across membranes,and transmit signal across membranes.Even,a viral infection is often initiated through virus-host protein interactions.Protein-protein interactions(PPIs)are the physical contacts between two or more proteins and they represent complex biological functions.Nowadays,PPIs have been used to construct PPI networks to study complex pathways for revealing the functions of unknown proteins.Scientists have used PPIs to find the molecular basis of certain diseases and also some potential drug targets.In this review,we will discuss how PPI networks are essential to understand the molecular basis of virus-host relationships and several databases which are dedicated to virus-host interaction studies.Here,we present a short but comprehensive review on PPIs,including the experimental and computational methods of finding PPIs,the databases dedicated to virus-host PPIs,and the associated various applications in protein interaction networks of some lethal viruses with their hosts. 展开更多
关键词 Protein-protein interactions experimental and computational methods Protein-protein interaction networks Protein-protein interaction databases Disease pathways Protein-protein interaction applications
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Experimental validation method of elastic thin rod model for simulating the motional cable harness
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作者 王春生 刘检华 +1 位作者 宁汝新 陈涛 《Journal of Beijing Institute of Technology》 EI CAS 2012年第2期192-197,共6页
To analyze the spring disturbance torque caused by motionai cable harness in a stabilized platform, the Kirchhoff theory based cable harness model has been previously developed to dynamically simulate the motional cab... To analyze the spring disturbance torque caused by motionai cable harness in a stabilized platform, the Kirchhoff theory based cable harness model has been previously developed to dynamically simulate the motional cable harness. In this paper, this model was validated by comparing the simulation results with the experiment results ( both the spring force and the deformed profile of the motional cable harness). In the experiment, a special optical measuring instrument based on binocular vision was developed and the motion and deformation of cable harness were measured. A simpli- fied stabilized platform system was constructed, and the absolute value of spring disturbance force during the motion of this simplified frame was obtained by using a force gauge (0. 02 N precision). The physical parameters of experimental specimen were also measured. The experimental and simulated results showed good agreement. These results should be useful for better motional cable harness layout design and reliable evaluation of the spring disturbance torque. 展开更多
关键词 experimental validation method binocular vision motional cable simulation Kirchhoffrod
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Numerical and Experimental Investigation of the Aero-Hydrodynamic Effect on the Behavior of a High-Speed Catamaran in Calm Water
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作者 Ali Ebrahimi Rouzbeh Shafaghat +1 位作者 Ali Hajiabadi Mahdi Yousefifard 《Journal of Marine Science and Application》 CSCD 2022年第3期56-70,共15页
In this paper,the effect of water and air fluids on the behavior of a planing catamaran in calm water was studied separately in calm water by using experimental and numerical methods.Experiments were conducted in a to... In this paper,the effect of water and air fluids on the behavior of a planing catamaran in calm water was studied separately in calm water by using experimental and numerical methods.Experiments were conducted in a towing tank over the Froude number range of 0.49–2.9 with two degrees of freedom.The model vessel displacement of 5.3 kg was implemented in experimental tests.Craft behavior was evaluated at the displacements of 5.3,4.6,and 4 kg by using the numerical method.The numerical simulation results for the hull’s resistance force were validated with similar experimental data.The fluid volume model was applied to simulate two-phase flow.The SST k-ωturbulence model was used to investigate the effect of turbulence on the catamaran.The results showed that in the planing mode,the contribution of air to pressure resistance increased by 55%,40%,and 60%at the mentioned displacements,whereas the contribution of air to friction resistance was less than 15%on average.The contribution of the air to the total lift force at the abovementioned displacements exceeded 70%,60%,and 50%in the planing mode but was less than 10%in the displacement mode.At the displacements of 5.3 and 4 kg,the area under the effect of maximum pressure moved around the center of gravity and caused porpoising longitudinal instability at the Froude numbers of 2.9 and 2.4,respectively.However,at the displacement of 4.6 kg,this effect did not occur,and the vessel maintained its stability. 展开更多
关键词 Planing catamaran Calm water experimental and numerical methods Pressure resistance Friction resistance Purposing longitudinal instability
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Experimental Plans Method to Formulate a Resin Concrete
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作者 Miloud Beddar Zinedine Boudaoud +1 位作者 Mohamed Aziz Chikouche Halima Saadia M'hammedi 《Journal of Civil Engineering and Architecture》 2012年第10期1376-1383,共8页
This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used w... This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used with two types of mineral fillers (dune sand and crushed sand), and with the addition of a marble powder to ensure the continuity of the particle size mixing granular. The lack of the methods for developing this kind of composite materials, had led us to perform an initial experimental approach to define the experimental field, that is to say determine the mass proportions of the various compounds of mixture of our study. In the second approach, we have established and implemented fully experimental plans with three factors namely: factor (1): sand, factor (2): resin, factor (3): marble powder. Test results being the density of polymer concrete and the mechanical resistances. Finally, multi-parameters regression allowed us to determine predictive mathematical models for the different responses of the study. Tests results showed that at three days we got a tensile strength of about 16 MPa with a resin concrete density of 1.9 g/cm3. This shows the advantages of this material. 展开更多
关键词 CONCRETE polyester resin experimental plans method mechanical resistance
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Experimental Acoustic Determination of the Void Fraction in Two-Phase Flow in Horizontal Pipelines
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作者 Fernando Augusto de Noronha Castro Pinto Thiago de Campos Negrelly Alexandre Silva de Lima 《Journal of Mechanics Engineering and Automation》 2014年第8期625-631,共7页
In multi-phase flows, the phases can flow and arranged in different spatial configurations in the pipe, which called flow patterns. This type of flow is found in the oil, chemical and nuclear industries. For example, ... In multi-phase flows, the phases can flow and arranged in different spatial configurations in the pipe, which called flow patterns. This type of flow is found in the oil, chemical and nuclear industries. For example, in the production and transport of oil and gas, the identification of the flow patterns are essential for answering those questions which are related to the economic return of the field, such as, measuring the volumetric flow, determining the pressure drop along the flow lines, production management and supervision. In offshore production, these factors are very important. This paper presents a new method for measuring the void fraction in horizontal pipelines, taking the air as gas in water-air two-phase flow. Through acoustic analysis of the frequency response of the pipe, the method gets the parameters to changes in runoff regime, in an experimental arrangement constructed on a small scale. The main advantages are the non-intrusive characteristic and easy to implement. The paper is composed of a qualitative experimental evaluation and transducers (microphone) which are used to analyze variations in the response accompanying variations in void and flow pattern changes. Changes are imposed and controlled by a two-phase flow experimental simulation rig, including a measurement cell constituted of an external casing that can isolate the measurement from the environmental background noise fitted with acoustic pressure transducers radially arranged, and the impact of a monitored excitation mechanism. The signals which captured by the microphones are processed and analyzed by checking their frequency contents changes according to the amount of air in the mixture. 展开更多
关键词 experimental method two-phase flow determination of void fraction horizontal pipelines.
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Evaluation of Full Experimental Design Method against Fractional Design Method and Taguchi Design Method in Machining Operation
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作者 Shakib Zohrevandi Mahdi Bashiri 《Journal of Control Science and Engineering》 2014年第1期43-51,共9页
DOE (design of experiments) is a systematic, rigorous approach to engineering problem-solving that applies principles and techniques at the data collection stage so as to ensure the generation of valid, defensible, ... DOE (design of experiments) is a systematic, rigorous approach to engineering problem-solving that applies principles and techniques at the data collection stage so as to ensure the generation of valid, defensible, and supportable engineering conclusions. This paper presents a comparison of three different experimental designs (full experimental design, fractional design and Taguchi design) aimed at studying the effects of cutting parameters variations on surface finish. The results revealed that the effects obtained by analyzing both fractional and Taguchi designs were comparable to the main effects and two-level interactions obtained by the full factorial design. Thus, we conclude that full factorial design appear to be reliable and more economical since they permit to reduce by a factor the amount of time and effort required to conduct the experimental design without losing valuable information. Thus, we conclude that full factorial design appear to be reliable and more economical and without losing valuable information. 展开更多
关键词 Full experimental design method design of experiments Taguchi design method fractional design method.
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Natural Monopoly and Mixed Ownership Reform--Based on Natural Experiment and Cost Function Analysis Method
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作者 Chen Lin 《China Economist》 2018年第5期60-83,共24页
Despite a multitude of theoretical discussions on China's mixed ownership reform, very few studies have addressed realistic questions concerning the implementation of the reform. The Resolutions of the Third Plenu... Despite a multitude of theoretical discussions on China's mixed ownership reform, very few studies have addressed realistic questions concerning the implementation of the reform. The Resolutions of the Third Plenum of the 18 th CPC Central Committee and other reform strategies have outlined the reform of sectors with natural monopoly, including urban public utility sectors. The question is how mixed ownership reform should be carried out in sectors of natural monopoly, or which public utilities sectors should enjoy priority of mixed ownership reform. To answer this question, this paper employs data of large public utility enterprises in China from 1998 to 2008, and estimates the natural monopoly attribute at the industry level and corporate total factor productivity(TFP) using cost function analysis method excluding the impact of product price factor. Based on the difference-indifferences-in-differences(DDD) method of natural experiment, an empirical test is carried out for the relationship among natural monopoly, mixed ownership reform and corporate productivity. Our results suggest that:(1) Statistically, mixed ownership reform cannot significantly increase corporate TFP in sectors with natural monopoly;(2) mixed ownership reform should not be carried out indiscriminately on a nationwide basis and for all public utilities sectors. Such an attempt of reform without distinguishing natural monopoly and the level of competitiveness is fraught with policy uncertainties;(3) relative to sectors with natural monopoly, corporate productivity in competitive sectors after mixed ownership reform will improve more significantly and enjoy greater "policy dividends" of institutional reform. Therefore, mixed ownership reform should be carried out first in competitive sectors. 展开更多
关键词 mixed OWNERSHIP REFORM NATURAL MONOPOLY cost function NATURAL experiment difference-in-differences-in-differences(DDD)method
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RECONSTRUCTION OF PART OF AN ACTUAL BLAST-WAVE FLOW FIELD TO AGREE WITH EXPERIMENTAL DATA BY USING NUMERICAL METHOD WITH HIGH IDENTIFICATION
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作者 吴清松 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第10期925-932,共8页
In this paper, on the basis of experimental data of two kinds of chemical explosions, the piston-pushing model of spherical blast-waves and the second-order Godunov-type scheme of finite difference methods with high i... In this paper, on the basis of experimental data of two kinds of chemical explosions, the piston-pushing model of spherical blast-waves and the second-order Godunov-type scheme of finite difference methods with high identification to discontinuity are used to the numerical reconstruction of part of an actual hemispherical blast-wave flow field by properly adjusting the moving bounary conditions of a piston. This method is simple and reliable. It is suitable to the evaluation of effects of the blast-wave flow field away from the explosion center. 展开更多
关键词 RECONSTRUCTION OF PART OF AN ACTUAL BLAST-WAVE FLOW FIELD TO AGREE WITH experimentAL DATA BY USING NUMERICAL METHOD WITH HIGH IDENTIFICATION ANFO TNT
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Experimental and Numerical Study of Wind Noise Caused by Cowl Area on Volvo XC60
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作者 Olga Roditcheva Par Harling +1 位作者 Dragos Moroianu Holger Bemhardsson 《Journal of Mechanics Engineering and Automation》 2016年第3期109-117,共9页
This paper presents a detailed experimental and numerical study of aerodynamically produced noise which occurs due to turbulent structures created by the cowl cavity and side mirror. Measurements were carried out at V... This paper presents a detailed experimental and numerical study of aerodynamically produced noise which occurs due to turbulent structures created by the cowl cavity and side mirror. Measurements were carried out at Volvo aerodynamical wind tunnel on a Volvo XC60 production model. The configurations considered here are: side mirror On/Off with the cowl cavity open/closed. The results of exterior sound source mapping (with the intensity probe placed in the flow stream) have been compared with the results of the measurements inside the car. The contribution of the cowl area to overall wind noise level is measured in terms of AI% (Articulation Index) inside the compartment. It was shown that increase in AI by 2% could be attributed to the cowl generated wind noise. Transient numerical simulations of the turbulent flow around the car have been performed for all configurations. The results of the simulations show similarity to experimental results and give insight to the flow structures around the car. 展开更多
关键词 Aerodynamically produced noise wind noise turbulent flow experimental and numerical methods for aeroacoustics sound sources ground vehicles.
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Visual Passive Ranging Method Based on Re-entrant Coaxial Optical Path and Experimental Verification
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作者 杨金宝 刘建国 +1 位作者 祝宁华 于丽娟 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第12期32-36,共5页
To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coa... To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection. 展开更多
关键词 Visual Passive Ranging Method Based on Re-entrant Coaxial Optical Path and experimental Verification
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A METHOD OF ESTIMATING THE INFLUENCE OF EXPERIMENTAL ERRORS ON THE EXPERIMENTAL RESULTS OF MATERIAL PARAMETERS AND THE CRITERIA TO VALUE THIS INFLUENCE
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作者 Yao Weixing Tsinghua University 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1991年第3期320-325,共6页
In this paper the main sources causing the scatter of the experimental results of the material parameters are discussed. They can be divided into two parts: one is the experimental errors which are introduced because ... In this paper the main sources causing the scatter of the experimental results of the material parameters are discussed. They can be divided into two parts: one is the experimental errors which are introduced because of the inaccuracy of experimental equipment, the experimental techniques, etc., and the form of the scatter caused by this source is called external distribution. The other is due to the irregularity and inhomogeneity of the material structure and the randomness of deformation process. The scatter caused by this source is inherent and then this form of the scatter is called internal distribution. Obviously the experimental distribution of material parameters combines these two distributions in some way; therefore, it is a sum distribution of the external distribution and the internal distribution. In view of this , a general method used to analyse the influence of the experimental errors on the experimental results is presented, and three criteria used to value this influence are defined. An example in which the fracture toughness KIC is analysed shows that this method is reasonable, convenient and effective. 展开更多
关键词 A METHOD OF ESTIMATING THE INFLUENCE OF experimentAL ERRORS ON THE experimentAL RESULTS OF MATERIAL PARAMETERS AND THE CRITERIA TO VALUE THIS INFLUENCE
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Sediment Erosion on Pelton Turbines:A Review 被引量:1
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作者 Xinfeng Ge Jie Sun +8 位作者 Dongdong Chu Juan Liu Ye Zhou Hui Zhang Lei Zhang Huixiang Chen Kan Kan Maxime Binama Yuan Zheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期36-62,共27页
The Pelton turbine has been widely used to develop high-head water resources with sediments because of its advantages in life cycle costs.When a flood or monsoon season occurs,the sediment concentration in the river i... The Pelton turbine has been widely used to develop high-head water resources with sediments because of its advantages in life cycle costs.When a flood or monsoon season occurs,the sediment concentration in the river increases suddenly,causing severe erosion to the nozzle,needle,and runner of Pelton turbines.After decades of development,researchers have developed practical engineering experience to reduce the sediment concentration of the flow through the turbine and ensure the safety and efficiency of power generation.Research on the mechanism of sediment erosion,development of anti-erosion materials,and establishment of erosion prediction models have attracted scholarly interest in recent years.Extensive research has been conducted to determine a complete and valuable syndication erosion model.However,owing to the complexity of the flow and wear mechanisms,the influence of specific parameters of erosion and the syndication effect is still difficult to determine.Computational fluid dynamics and erosion monitoring technology have also been evaluated and applied.This paper presents a comprehensive review of the erosion of Pelton turbines,some of the latest technical methods,and possible future development directions. 展开更多
关键词 Pelton turbine Sediment erosion Sediment erosion mechanism CFD The experimental method
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Field experimental study on the effect of thawed depth of frozen alpine meadow soil on rill erosion by snowmelt waterflow 被引量:1
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作者 Ying Zheng Xiaonan Shi +5 位作者 Fan Zhang Tingwu Lei Chen Zeng Xiong Xiao Li Wang Guanxing Wang 《International Soil and Water Conservation Research》 SCIE CSCD 2024年第1期54-63,共10页
Soil erosion by snow or ice melt waterflow is an important type of soil erosion in many high-altitude and high-latitude regions and is further aggravated by climate warming.The snowmelt waterflow erosion process is af... Soil erosion by snow or ice melt waterflow is an important type of soil erosion in many high-altitude and high-latitude regions and is further aggravated by climate warming.The snowmelt waterflow erosion process is affected by soil freeze-thaws and is highly dynamically variable.In this study,a methodology was developed to conduct in situ field experiments to investigate the effects of the thawed depth of the frozen soil profile on snowmelt waterflow erosion.The method was implemented on an alpine meadow soil slope at an altitude of 3700 m on the northeastern Tibetan Plateau.The erosion experiments involved five thawed soil depths of 0,10,30(35),50,and 80(100)mm under two snowmelt waterflow rates(3 and 5 L/min).When the topsoil was fully frozen or shallow-thawed(≤10 mm),its hydrothermal and structural properties caused a significant lag in the initiation of runoff and delayed soil erosion in the initial stage.The runoff and sediment concentration curves for fully frozen and shallow-thawed soil showed two-stage patterns characteristic of a sediment supply limited in the early stage and subject to hydrodynamic-controlled processes in the later stage.However,this effect did not exist where the thawed soil depth was greater than 30 mm.The deep-thawed cases(≥30 mm)showed normal hydrograph and sedigraph patterns similar to those of the unfrozen soil.The findings of this study are important for understanding the erosion rates of partially thawed soil and for improving erosion simulations in cold regions. 展开更多
关键词 Snowmelt waterflow erosion Hillslope erosion process Soil freeze and thaw Runoff generation In situ experimental method
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