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Test Analysis of Traction Battery Peak Power 被引量:1
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作者 李红林 张承宁 +1 位作者 孙逢春 何士娟 《Journal of Beijing Institute of Technology》 EI CAS 2004年第4期422-425,共4页
The test process of electric vehicles (EVs) traction battery peak power is analyzed in detail. Aimed at a special “traction” design of versatile battery—HORIZON~ C~2M Battery, the features are introduced. According... The test process of electric vehicles (EVs) traction battery peak power is analyzed in detail. Aimed at a special “traction” design of versatile battery—HORIZON~ C~2M Battery, the features are introduced. According to the peak power test schedule, the test parameters of HORIZON~ C~2M Battery are calculated and the charging and discharging experiments are carried out. The sustained (30 s) discharge power capability of battery at 2/3 of its open circuit voltage at each of various depths of discharge is determined. The dynamic internal resistance under peak power test is established. Considering the temperature impact during discharging, the peak power capability at each of various depths of discharge is corrected. The correctness of peak power test is validated by combining theory analysis with test results. 展开更多
关键词 test analysis traction battery peak power electric vehicle
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A well test analysis model of generalized tube flow and seepage coupling
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作者 LIN Jia'en HE Hui WANG Yihua 《Petroleum Exploration and Development》 CSCD 2021年第4期923-934,共12页
"Generalized mobility"is used to realize the unification of tube flow and seepage in form and the unification of commonly used linear and nonlinear flow laws in form,which makes it possible to use the same f... "Generalized mobility"is used to realize the unification of tube flow and seepage in form and the unification of commonly used linear and nonlinear flow laws in form,which makes it possible to use the same form of motion equations to construct unified governing equations for reservoirs of different scales in different regions.Firstly,by defining the generalized mobility under different flow conditions,the basic equation governing fluid flow in reservoir coupling generalized tube flow and seepage is established.Secondly,two typical well test analysis models for coupling tube flow and seepage flow are given,namely,pipe-shaped composite reservoir model and partially open cylindrical reservoir model.The log-log pressure draw-down type-curve of composite pipe-shaped reservoir model can show characteristics of two sets of linear flow.The log-log pressure drawdown plot of partially opened cylindrical reservoir model can show the characteristics of spherical flow and linear flow,as well as spherical flow and radial flow.The pressure build-up derivative curves of the two models basically coincide with their respective pressure drawdown derivative curves in the early stage,pulling down features in the late stage,and the shorter the production time is,the earlier the pulling down feature appears.Finally,the practicability and reliability of the models presented in this paper are verified by three application examples. 展开更多
关键词 generalized mobility complex reservoir multiphase flow coupled tube flow and seepage well test analysis
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Transient pressure analysis of polymer flooding fractured wells with oil-water two-phase flow
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作者 WANG Yang YU Haiyang +2 位作者 ZHANG Jia FENG Naichao CHENG Shiqing 《Petroleum Exploration and Development》 2023年第1期175-182,共8页
The oil-water two-phase flow pressure-transient analysis model for polymer flooding fractured well is established by considering the comprehensive effects of polymer shear thinning,shear thickening,convection,diffusio... The oil-water two-phase flow pressure-transient analysis model for polymer flooding fractured well is established by considering the comprehensive effects of polymer shear thinning,shear thickening,convection,diffusion,adsorption retention,inaccessible pore volume and effective permeability reduction.The finite volume difference and Newton iteration methods are applied to solve the model,and the effects of fracture conductivity coefficient,injected polymer mass concentration,initial polymer mass concentration and water saturation on the well-test type curves of polymer flooding fractured wells are discussed.The results show that with the increase of fracture conductivity coefficient,the pressure conduction becomes faster and the pressure drop becomes smaller,so the pressure curve of transitional flow goes downward,the duration of bilinear flow becomes shorter,and the linear flow appears earlier and lasts longer.As the injected polymer mass concentration increases,the effective water phase viscosity increases,and the pressure loss increases,so the pressure and pressure derivative curves go upward,and the bilinear flow segment becomes shorter.As the initial polymer mass concentration increases,the effective water phase viscosity increases,so the pressure curve after the wellbore storage segment moves upward as a whole.As the water saturation increases,the relative permeability of water increases,the relative permeability of oil decreases,the total oil-water two-phase mobility becomes larger,and the pressure loss is reduced,so the pressure curve after the wellbore storage segment moves downward as a whole.The reliability and practicability of this new model are verified by the comparison of the results from simplified model and commercial well test software,and the actual well test data. 展开更多
关键词 fractured vertical well polymer flooding two-phase flow well test analysis model type curve influence factor
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Test and Analysis of the Sound Insulation Performance of Four Types of Timber Structure Floors under Jumping Excitation 被引量:1
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作者 Yujie Huang Hao Zhu +3 位作者 Dauletbek Assima Zheng Wang Minmin Li Xinyue Zhao 《Journal of Renewable Materials》 SCIE EI 2021年第4期829-840,共12页
To improve the impact sound insulation performance of building floors and meet the objective requirements for living comfort of residents,in this article,three kinds of elastic cushion materials,Portuguese cork board,... To improve the impact sound insulation performance of building floors and meet the objective requirements for living comfort of residents,in this article,three kinds of elastic cushion materials,Portuguese cork board,BGL insulation sound insulation foam board,and EPP polypropylene plastic foam board,are applied to the sound insulation of a light frame wood floor structure of the same bedroom and compared to the ordinary floor.This study uses the transfer function method and transient excitation method to measure the sound insulation,damping ratio,and elastic modulus of materials,as well as the sound insulation of the floor under the jumping excitation method of daily behavior.Through comparative analysis,the results and factors of improving the sound insulation performance of the floor are obtained,according to which three types of elastic cushion materials and the floor covering composed of them have higher vibration and noise reduction performance.Among them,the overall sound insulation performance of BGL board floor is the highest,followed by EPP board and cork board floor,and ordinary OSB floor is the lowest.Under the jumping excitation method,three floating floors can improve the impact sound insulation performance of the middle and low-frequency bands. 展开更多
关键词 Timber floor structure elastic cushion material damping ratio elastic modulus jumping excitation method of daily behavior testing and comparative analysis
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Approach for Obtaining Material Mechanical Properties in Local Region of Structure Based on Accurate Analysis of Micro-indentation Test
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作者 He Xue Jinxuan He +1 位作者 Jianlong Zhang Yuxuan Xue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第6期147-158,共12页
The hot or cold processing would induce the change and the inhomogeneous of the material mechanical properties in the local processing region of the structure,and it is difficult to obtain the specific mechanical prop... The hot or cold processing would induce the change and the inhomogeneous of the material mechanical properties in the local processing region of the structure,and it is difficult to obtain the specific mechanical properties in these regions by using the traditional material tensile test.To accurately get actual material mechanical properties in the local region of structure,a micro-indentation test system incorporated by an electronic universal material test device has been established.An indenter displacement sensor and a group of special micro-indenter assemblies are estab-lished.A numerical indentation inversion analysis method by using ABAQUS software is also proposed in this study.Based on the above test system and analysis platform,an approach to obtaining material mechanical properties in the local region of structures is proposed and established.The ball indentation test is performed and combined with the energy method by using various changed mechanical properties of 316L austenitic stainless steel under differ-ent elongations.The investigated results indicate that the material mechanical properties and the micro-indentation morphological changes have evidently relevance.Compared with the tensile test results,the deviations of material mechanical parameters,such as hardness H,the hardening exponent n,the yield strength σy and others are within 5%obtained through the indentation test and the finite element analysis.It provides an effective and convenient method for obtaining the actual material mechanical properties in the local processing region of the structure. 展开更多
关键词 Structural integrity assessment Micro-indentation test Numerical testing inversion analysis Local material mechanical property
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Dimensional analysis of the impact toughness test for synthetic diamond grits
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作者 杨慧 麦绿波 +4 位作者 卢灿华 仝毅 王志涛 张凤岭 黄风雷 《Journal of Beijing Institute of Technology》 EI CAS 2016年第1期1-6,共6页
The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the dia... The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the diamond,has been well established for many years.However,the unbroken percentage,in an equivalent view,represents the impact toughness of the grits and cannot reflect the value of the crushing energy.Most of the previous empirical formulas obtained from experiments by scholars cannot be applied to practical tests.In this paper,a dimensional analysis was applied to investigate the impact toughness experiment,and the dimensionless relationship has been built among those variables such as the toughness index,the impact time,the impact frequency and the crushing energy per unit area.According to the results of a large number of experiments with synthetic diamond grits of mesh size 45/50,the percentage of the broken grits H is proportional to the impact time T^(1.14) when the impact frequency is 2400 r/min,and the impact frequency f^(2.576) when the number of impacts is 2000. 展开更多
关键词 synthetic diamond toughness index dimensional analysis impact toughness test
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New Configurations of the Fuzzy Fractional Differential Boussinesq Model with Application in Ocean Engineering and Their Analysis in Statistical Theory
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作者 Yu-Ming Chu SaimaRashid +1 位作者 Shazia Karim Anam Sultan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第11期1573-1611,共39页
The fractional-order Boussinesq equations(FBSQe)are investigated in this work to see if they can effectively improve the situation where the shallow water equation cannot directly handle the dispersion wave.The fuzzy ... The fractional-order Boussinesq equations(FBSQe)are investigated in this work to see if they can effectively improve the situation where the shallow water equation cannot directly handle the dispersion wave.The fuzzy forms of analytical FBSQe solutions are first derived using the Adomian decomposition method.It also occurs on the sea floor as opposed to at the functionality.A set of dynamical partial differential equations(PDEs)in this article exemplify an unconfined aquifer flow implication.Thismethodology can accurately simulate climatological intrinsic waves,so the ripples are spread across a large demographic zone.The Aboodh transform merged with the mechanism of Adomian decomposition is implemented to obtain the fuzzified FBSQe in R,R^(n) and(2nth)-order involving generalized Hukuhara differentiability.According to the system parameter,we classify the qualitative features of the Aboodh transform in the fuzzified Caputo and Atangana-Baleanu-Caputo fractional derivative formulations,which are addressed in detail.The illustrations depict a comparison analysis between the both fractional operators under gH-differentiability,as well as the appropriate attributes for the fractional-order and unpredictability factorsσ∈[0,1].A statistical experiment is conducted between the findings of both fractional derivatives to prevent changing the hypothesis after the results are known.Based on the suggested analyses,hydrodynamic technicians,as irrigation or aquifer quality experts,may be capable of obtaining an appropriate storage intensity amount,including an unpredictability threshold. 展开更多
关键词 Fuzzy set theory aboodh transform adomian decomposition method boussinesq equation fractional derivative operators analysis of variance test
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Classification of carbonate gas condensate reservoirs using well test and production data analyses 被引量:3
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作者 Li Yong Li Baozhu +5 位作者 Hu Yongle Xia Jing Liu Zhaowei Deng Xingliang She Zhicheng Fan Kun 《Petroleum Science》 SCIE CAS CSCD 2011年第1期70-78,共9页
Carbonate reservoir patterns play an important role in the production performance of oil and gas wells,and it is usually classified through static data analysis which cannot reflect the actual well performance.This pa... Carbonate reservoir patterns play an important role in the production performance of oil and gas wells,and it is usually classified through static data analysis which cannot reflect the actual well performance.This paper takes the Tazhong No.1 gas field in the Tarim Basin,China as an example to investigate the classification of carbonate reservoirs.The classification method mainly combines well test analysis with production analysis—especially the Blasingame type curve method.Based on the characteristics of type curves for well test analysis and the Blasingame method,the relationship between the type curves and reservoir pattern was established.More than 20 wells were analyzed and the reservoirs were classified into 3 major patterns with 7 sub-classes.Furthermore,the classification results were validated by dynamic performance analysis of wells in the Tazhong No.1 gas field.On the basis of the classification results,well stimulation(i.e.water flooding in a single well) was carried out in three volatile-oil wells,and the oil recovery increased by up to 20%. 展开更多
关键词 CARBONATE reservoir pattern well test analysis production analysis type curve
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Dynamic Test of Hydro Mechanical Composite Transmission for Cotton Picker 被引量:2
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作者 Xiangdong Ni Mingxi Bao 《Journal of Beijing Institute of Technology》 EI CAS 2020年第3期366-378,共13页
With a transmission system suitable for a medium or large self-propelled cotton picker as the object of the study,the following work focuses on the influence law of an independently designed hydro-mechanical continuou... With a transmission system suitable for a medium or large self-propelled cotton picker as the object of the study,the following work focuses on the influence law of an independently designed hydro-mechanical continuously variable transmission(HMCVT)in the process of changing sections.An HMCVT simulation model was established using the multibody dynamics Simulation X software.The accuracy of the simulation model was verified by comparing the numerical values of the output speed of the HMCVT with model predictions.The HMCVT test bench was built independently using a John Deere 4045HYC11 diesel engine as power input.The engine speed,load torque,oil pressure,and flow of speed regulating valve were considered the influencing factors.The sliding friction power was the response index for the segment change process test.We analysed the reasons for the decrease in output speed during the shifting process,and proposed to effectively reduce the stable speed difference before and after the output shaft shifting by shifting the stage ahead(with displacement ratio of-0.96).This study provides a reference value for the smoothness of the HMCVT of the self-propelled cotton picker,and is relevant in promoting the use of the cotton picker. 展开更多
关键词 transmission scheme shifting process test analysis dynamic characteristics
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HORIZONTAL WELL PRESSURE ANALYSIS IN BOX-BOUNDED RESERVOIRS
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作者 王晓冬 刘慈群 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第4期315-320,共6页
In this paper, solutions to the 3D transient flow mathematical model for horizontal wells in box-rounded reservoirs are presented. The solutions are derived in Laplace transform domain by employing integral transform ... In this paper, solutions to the 3D transient flow mathematical model for horizontal wells in box-rounded reservoirs are presented. The solutions are derived in Laplace transform domain by employing integral transform and point-source superposition. Both efficient computation of pressure responses and practical technology of oil field application mentioned here may be used to interpret the data from unsteady-state horizontal well testing. 展开更多
关键词 horizontal well transient flow in porous media mathematical model PRESSURE pressure derivatives well test analysis
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GENERALIZED FLOW ANALYSIS OF NON-NEWTONIAN VISCO-ELASTICFLUID FLOW THROUGH FRACTAL RESERVOIR
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作者 同登科 陈钦雷 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第12期1367-1376,共10页
In this paper, fractal geometry theory is used to combine with the seepage flow mechanics to establish the relaxation models of non_Newtonian visco_elastic fluid flow in fractal reservoirs. A method to scale the fract... In this paper, fractal geometry theory is used to combine with the seepage flow mechanics to establish the relaxation models of non_Newtonian visco_elastic fluid flow in fractal reservoirs. A method to scale the fractal properties of a fractal reservoir by the double parameters (d f ,d s ) and to describe the generalized flow characteristics of visco_elastic fluid by four parameters (d f ,d s ,λ v,λ p) are presented. Exact solutions and asymptotic solutions have been obtained by using the Laplace_Weber and Laplace_orthogonal transforms with both infinite and finite reservoirs. The pressure transient behavior of non_Newtonian visco_elastic fluid flow through a fractal reservoir are studied by using the numerical Laplace transform inversion and asymptotic solutions. The law of pressure change for various fractal parameters is obtained. 展开更多
关键词 visco_elastic fluid FRACTAL integral transform well test analysis
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BRAKE TEST OF SiCp/A356 BRAKE DISK AND INTERPRETATION OF EXPERIMENTAL RESULTS 被引量:3
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作者 YANG Zhiyong HAN Jianmin LI Weijing WANG Jinhua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第5期74-79,共6页
Material properties are obvious different between aluminum matrix composites and iron and steel materials. After the brake disk braked at the same speed, the average temperature of the aluminum brake disk is 1.5 times... Material properties are obvious different between aluminum matrix composites and iron and steel materials. After the brake disk braked at the same speed, the average temperature of the aluminum brake disk is 1.5 times as high as one of iron and steel brake disk, the thermal expansion value of the aluminum brake disk is 2 times as big as one of iron and steel brake disk. Mechanical property of the material decreases with the temperature increasing generally during braking, on the other hand, the big thermal stress in the brake disk happens because the material expansion is constrained. Firstly, the reasons of the thermal stress generation and the fracture failure of brake disks during braking are analyzed qualitatively by virtue of three-bar stress frame and sandwich deformation principles in physic, and then the five constraints which cause the thermal stress are summarized. On the base of the experimental results on the 1:1 emergency brake test, the thermal stress and temperature fields are simulated; The behavior of the fracture failure is interpreted semi-quantitatively by finite element analysis, There is the coincident forecast for the fraction position in term of the two methods. In the end, in the light of the analysis and calculation results, it is the general principles observed by the structure design and assembly of the brake disk that are summarized. 展开更多
关键词 Brake disk Brake test Thermal stress Heat flux Finite element analysis
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Combinatorial Method with Static Analysis for Source Code Security in Web Applications
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作者 Juan Ramon Bermejo Higuera Javier Bermejo Higuera +3 位作者 Juan Antonio Sicilia Montalvo Tomas Sureda Riera Christopher I.Argyros A.Alberto Magrenan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第11期541-565,共25页
Security weaknesses in web applications deployed in cloud architectures can seriously affect its data confidentiality and integrity.The construction of the procedure utilized in the static analysis tools of source cod... Security weaknesses in web applications deployed in cloud architectures can seriously affect its data confidentiality and integrity.The construction of the procedure utilized in the static analysis tools of source code security differs and therefore each tool finds a different number of each weakness type for which it is designed.To utilize the possible synergies different static analysis tools may process,this work uses a new method to combine several source codes aiming to investigate how to increase the performance of security weakness detection while reducing the number of false positives.Specifically,five static analysis tools will be combined with the designed method to study their behavior using an updated benchmark for OWASP Top Ten Security Weaknesses(OWASP TTSW).The method selects specific metrics to rank the tools for different criticality levels of web applications considering different weights in the ratios.The findings show that simply including more tools in a combination is not synonymous with better results;it depends on the specific tools included in the combination due to their different designs and techniques. 展开更多
关键词 WEAKNESS BENCHMARK security testing analysis comparative methodology tools combination web application
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Precipitation Forecast Test Based on MODE
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作者 Wang Xuelian Xie Yiyang +2 位作者 Li Yinghua Chen Min Zhong Jiqin 《Meteorological and Environmental Research》 CAS 2014年第2期5-8,共4页
Abstract By testing and analyzing BJ-RUC forecast of one precipitation process, MODE was introduced. MODE could give objective comparison from position of precipitation falling zone, shape and direction, and reflect i... Abstract By testing and analyzing BJ-RUC forecast of one precipitation process, MODE was introduced. MODE could give objective comparison from position of precipitation falling zone, shape and direction, and reflect intensity difference between forecast and actual situation, which comprehensively reflected precipitation forecast performance of the model, and was close to subjective judgment thinking of forecaster. 展开更多
关键词 MODE Precipitation forecast testing and analysis China
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DETERMINATION OF CREEP PROPERTIES OF THERMAL BARRIER COATING(TBC)SYSTEMS FROM THE INDENTATION CREEP TESTING WITH ROUND FLAT INDENTERS
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作者 B.Zhao B.X.Xu +1 位作者 J.Liu Z.F.Yue 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第4期503-508,共6页
Indentation creep behavior with cylindrical flat indenters on the thermal barrier coating (TBC) was studied by finite element method (FEM). On ike constant applied indentation creep stress, there is a steady creep rat... Indentation creep behavior with cylindrical flat indenters on the thermal barrier coating (TBC) was studied by finite element method (FEM). On ike constant applied indentation creep stress, there is a steady creep rate for each case studied for different creep properties of the TBC system. The steady creep depth rate depends on the applied indentation creep stress and size of the indenters as well as the creep properties of the bond coat of the TBC and the substrate. The possibilities to determine the creep properties of a thermal barrier system from indention creep testing were discussed. As an example, with two different size indenters, the creep properties of bond coat of the TBC system can be derived by an inverse FEM method. This study not only provides a numerical method to obtain the creep properties of the TBC system, but also extends the application of indentation creep method with cylindrical flat indenters. 展开更多
关键词 thermal barrier coating (TBC) system indention creep testing finite element creep analysis determination of creep parameters bond coat
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Parameters analysis and application of the differential excitation detection technology
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作者 于霞 张卫民 +2 位作者 陈国龙 邱忠超 曾卫琴 《Journal of Beijing Institute of Technology》 EI CAS 2015年第3期348-354,共7页
A differential excitation probe based on eddy current testing technology was designed. Sheet specimens of Q 235 steel with prefabricated micro-cracks of different widths and of aluminum with prefabricated micro-cracks... A differential excitation probe based on eddy current testing technology was designed. Sheet specimens of Q 235 steel with prefabricated micro-cracks of different widths and of aluminum with prefabricated micro-cracks of different depths were detected through the designed detection system. The characteristics of micro-cracks can be clearly showed after signals processing through the short-time Fourier transform( STFT). By changing the parameter and its value in detecting process,the factors including the excitation frequency and amplitude,the lift-off effect and the scanning direction were discussed,respectively. The results showed that the differential excitation probe was insensitive to dimension and surface state of the tested specimen,while it had a high degree of recognition for micro-crack detection. Therefore,when the differential excitation detection technology was used for inspecting micro-crack of turbine blade in aero-engine,and smoothed pseudo Wigner-Ville distribution was used for signal processing,micro-cracks of 0. 3 mm depth and 0. 1 mm width could be identified. The experimental results might be useful for further research on engineering test of turbine blades of aero-engine. 展开更多
关键词 differential excitation probe eddy current testing micro-crack defect influence parameters analysis
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ANALYSIS ON EPITOPES OF IGM WITH MONOCLONAL ANTI-ISOTYPIC AND ANTI-IDIOTYPIC ANTIBODIES AGAINST IgM FROM B-CLL
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作者 沈关心 苏娜 +3 位作者 王晓林 朱慧芬 张悦 秦立轩 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1992年第4期36-42,共7页
A double antibodies additivity ELISA test was employed to identify the epltopes which can be recognized by monoclonal antibodies (McAbs) against IgM from B chronic lymphocyte leukemia (B-CLL). The computer grouping pr... A double antibodies additivity ELISA test was employed to identify the epltopes which can be recognized by monoclonal antibodies (McAbs) against IgM from B chronic lymphocyte leukemia (B-CLL). The computer grouping programme analysis showed that 4 and- isotypic MaAbs could be divided into two groups and 10 anti- idiotype McAbs could be divided into four groups. The result was consistent with that of the indirect sandwich ELISA and inhibition ELISA test. It suggested that there were at least 6 distinct IgM epitopes which can react specifically with 14 McAbs. Our study indicated that the combination of the additivity ELISA test and the computer grouping programme analysis is of help in studying the relationship of the structure and function of antigen. 展开更多
关键词 antigen epltope antibody monoclonal additivity ELISA test B chronic lymphocyte leukemia computer grouping programme analysis.
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Predicting stability of integrated circuit test equipment using upper side boundary values of normal distribution
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作者 Zhan Wenfa Hu Xinyi +3 位作者 Zheng Jiangyun Yu Chuxian Cai Xueyuan Zhang Lihua 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2024年第2期85-93,共9页
In response to the growing complexity and performance of integrated circuit(IC),there is an urgent need to enhance the testing and stability of IC test equipment.A method was proposed to predict equipment stability us... In response to the growing complexity and performance of integrated circuit(IC),there is an urgent need to enhance the testing and stability of IC test equipment.A method was proposed to predict equipment stability using the upper side boundary value of normal distribution.Initially,the K-means clustering algorithm classifies and analyzes sample data.The accuracy of this boundary value is compared under two common confidence levels to select the optimal threshold.A range is then defined to categorize unqualified test data.Through experimental verification,the method achieves the purpose of measuring the stability of qualitative IC equipment through a deterministic threshold value and judging the stability of the equipment by comparing the number of unqualified data with the threshold value,which realizes the goal of long-term operation monitoring and stability analysis of IC test equipment. 展开更多
关键词 K-means clustering algorithm the upper side boundary of normal distribution THRESHOLD integrated circuit(IC)test equipment stability analysis
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基于4~20 mA输出的温湿度传感器设计 被引量:4
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作者 任勇峰 朱泽珲 贾兴中 《电子设计工程》 2021年第16期110-114,共5页
基于工业现场温湿度信号的测量,为解决温湿度传感器测量信号远距离传输时受噪声干扰、线路阻抗等的影响,利用4~20 mA电流环的抗干扰特性,采用电流进行信号传输,使电路的传输性能大大提高。设计采用SHT15作为测温、测湿的敏感元件,利用C8... 基于工业现场温湿度信号的测量,为解决温湿度传感器测量信号远距离传输时受噪声干扰、线路阻抗等的影响,利用4~20 mA电流环的抗干扰特性,采用电流进行信号传输,使电路的传输性能大大提高。设计采用SHT15作为测温、测湿的敏感元件,利用C8051F410单片机的IDAC功能,将测得的温湿度数字量转化成模拟量。再经过适当调理转换电路,并通过软件程序设计改善测量信号的线性度,实现4~20 mA的电流输出。最后利用标准温湿度测量设备进行测试试验分析,验证温湿度传感器的4~20 mA电路可以实现高精度的温湿度测量。 展开更多
关键词 4~20 mA电流环 SHT15 IDAC 调理转换电路 试验分析
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THE FLOW PROBLEM OF FLUIDS FLOW IN A FRACTAL RESERVOIR WITH DOUBLE POROSITY
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作者 TONG Deng-ke(同登科) +1 位作者 Zhang Hong-qing(张鸿庆) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第10期1118-1126,共9页
The effective radius of oil well is introduced in the inner boundary in the problem of fluids flow through fractal reservoir with double porosity, and thus a new model is established. Taking the wellbore storage and s... The effective radius of oil well is introduced in the inner boundary in the problem of fluids flow through fractal reservoir with double porosity, and thus a new model is established. Taking the wellbore storage and steady-state skin effect into consideration, the exact solutions of the pressure distribution of fluids flow in fractal reservoirs with double porosity are given for the cases of an infinite outer boundary, a finite closed outer boundary and a bounded domain with the constant pressure outer boundary conditions. The pressure behavior of fractal reservoir with double porosity is analyzed by using a numerical inversion of the Laplace transform solution. The pressure responses of changing various parameters are discussed. 展开更多
关键词 FRACTAL double porous media SEEPAGE well test analysis
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