期刊文献+
共找到9,184篇文章
< 1 2 250 >
每页显示 20 50 100
Optimizing Average Electric Power During the Charging of Lithium-Ion Batteries Through the Taguchi Method
1
作者 Mohd H.S.Alrashdan 《Transactions of Tianjin University》 EI CAS 2024年第2期152-166,共15页
In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries fa... In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17 W during charging were designed and simulated in the range of 0-12000 s using COMSOL Multiphysics software. This study efficiently employs the Taguchi optimization technique to develop lithium-ion batteries capable of storing a predetermined average electric power during the charging phase. Therefore, this method enables the battery to achieve complete charging within a specific timeframe tailored to a specificapplication. The implementation of this method can save costs, time, and materials compared with other alternative methods, such as the trial-and-error approach. 展开更多
关键词 Lithium-ion batteries Average electric power during charging Taguchi method COMSOL Multiphysics software C rate L27 orthogonal array
下载PDF
The Challenges in Electrical and Electronic Technology Courses in Vocational Colleges
2
作者 Yifei Kang Meiqin Liang 《Journal of Contemporary Educational Research》 2024年第5期194-199,共6页
This paper addresses the challenges in the teaching of electrical and electronic technology in higher vocational colleges and proposes specific countermeasures to improve teaching quality and effectiveness.The counter... This paper addresses the challenges in the teaching of electrical and electronic technology in higher vocational colleges and proposes specific countermeasures to improve teaching quality and effectiveness.The countermeasures include optimizing teaching content,emphasizing practical application and innovation,innovating teaching methods,introducing modern instructional approaches,strengthening the teaching team,enhancing teacher quality and practical expertise,upgrading experimental equipment and facilities,enriching curriculum resources,and incorporating digital teaching materials.These measures aim to cultivate high-quality skilled talents,promote social and economic development,and enhance national competitiveness.By adjusting the course structure,incorporating real-world industry cases,and fostering collaboration with enterprises,students can better understand and apply electrical and electronic technology.The introduction of project-based teaching,flipped classrooms,and multimedia technology can enhance student engagement and facilitate independent learning.Furthermore,the improvement of experimental resources and the establishment of online teaching platforms can enhance students’practical skills and provide a variety of learning resources.These measures contribute to the overall improvement of electrical and electronic technology teaching in higher vocational colleges. 展开更多
关键词 electrical and electronic technology Vocational colleges Teaching challenges Teaching methods Digital materials
下载PDF
Exploration of French-Chinese Translation Methods of Electrical Engineering Terminology Using Online Image-Text Retrieval Mode
3
作者 Tian Li 《Journal of Contemporary Educational Research》 2023年第6期47-52,共6页
With the incessant propulsion of the Open Door Policy,which is related to the consolidation of international collaborative partnerships,an increasing number of Chinese companies are moving toward cooperating countries... With the incessant propulsion of the Open Door Policy,which is related to the consolidation of international collaborative partnerships,an increasing number of Chinese companies are moving toward cooperating countries to participate in infrastructure construction,employing a win-win strategy in favor of the people and governments of both countries.Among the cooperation domains,our country’s electrical companies have achieved a series of remarkable results in the international Engineering,Procurement,and Construction(EPC)project market with their outstanding business capabilities and technical advantages.Nevertheless,some shortcomings cannot be overlooked,the most notable of which appears to be the impediment associated with engineering translation,which has always been an obsession among translators of Chinese companies.Taking the transmission line project in the Republic of Madagascar as an example,an analysis of French-Chinese translation methods of electrical engineering terminology in the field of the transmission line is carried out. 展开更多
关键词 Engineering translation Translation methods electrical engineering terminology Interdisciplinary communication Online image-text retrieval mode
下载PDF
基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II决策方法
4
作者 杨威 李静 《工程数学学报》 CSCD 北大核心 2024年第3期525-539,共15页
针对属性权重完全未知或部分已知,属性值为区间毕达哥拉斯犹豫模糊数的多属性决策问题,提出了基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II法。首先给出区间毕达哥拉斯犹豫模糊数的区间形式的得分函数和精度函数,定义新的距离测... 针对属性权重完全未知或部分已知,属性值为区间毕达哥拉斯犹豫模糊数的多属性决策问题,提出了基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II法。首先给出区间毕达哥拉斯犹豫模糊数的区间形式的得分函数和精度函数,定义新的距离测度。然后基于区间毕达哥拉斯犹豫模糊数的模糊因子、直觉因子和幅度因子,给出熵和交叉熵公式,并证明其性质,提出了基于熵和交叉熵确定属性权重的方法。最后提出了区间毕达哥拉斯犹豫模糊环境下的改进的ELECTRE II法,利用综合优势值对方案进行排序,并通过算例和比较分析验证了该方法的可行性和有效性。 展开更多
关键词 多属性决策 区间毕达哥拉斯犹豫模糊集 交叉熵 electrE II法
下载PDF
A finite volume method for global electromagnetic induction forward modeling on collocated unstructured grids 被引量:1
5
作者 Liang Yin ZhengYong Ren +1 位作者 HongBo Yao Cong Yang 《Earth and Planetary Physics》 EI CSCD 2023年第1期57-65,共9页
Global electromagnetic induction provides an efficient way to probe the electrical conductivity in the Earth’s deep interior.Owing to the increasing geomagnetic data especially from high-accuracy geomagnetic satellit... Global electromagnetic induction provides an efficient way to probe the electrical conductivity in the Earth’s deep interior.Owing to the increasing geomagnetic data especially from high-accuracy geomagnetic satellites,inverting the Earth’s three-dimensional conductivity distribution on a global scale becomes attainable.A key requirement in the global conductivity inversion is to have a forward solver with high-accuracy and efficiency.In this study,a finite volume method for global electromagnetic induction forward modeling is developed based on unstructured grids.Arbitrary polyhedral grids are supported in our algorithms to obtain high geometric adaptability.We employ a cell-centered collocated variable arrangement which allows convenient discretization for complex geometries and straightforward implementation of multigrid technique.To validate the method,we test our code with two synthetic models and compare our finite volume results with an analytical solution and a finite element numerical solution.Good agreements are observed between our solution and other results,indicating acceptable accuracy of the proposed method. 展开更多
关键词 global electromagnetic induction mantle electrical conductivity finite volume method unstructured grids
下载PDF
Hyperbolic Method to Analyze the Electrical Resistivity Curve of Portland Cements with Superplasticizer 被引量:7
6
作者 WEI Xiaosheng XIAO Lianzhen LI Zongjin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第2期245-248,共4页
Electrical measurement was employed to investigate the early hydration characteristics of cement pastes with different dosages of superplasticizer in the same W/C ratio. The hyperbolic method was applied to analyze th... Electrical measurement was employed to investigate the early hydration characteristics of cement pastes with different dosages of superplasticizer in the same W/C ratio. The hyperbolic method was applied to analyze the electrical resistivity development. The peak point (Ph) on the hyperbolic curve could be easily read. The time (th) to reach the point Ph had strong relations with the setting time. th was delayed with the increment of the dosage of superplasticizer. The time th was used to plot the relationship between the initial setting time and final setting time. The hyperbolic equation was established to predict the ultimate resistivity. The retardation effect of the superplasticizer was confirmed in the same W/C ratio by setting time and isothermal heat evolution. 展开更多
关键词 electrical resistivity setting time SUPERPLASTICIZER HYDRATION hyperbolic method
下载PDF
Early Age Compressive Strength of Pastes by Electrical Resistivity Method and Maturity Method 被引量:2
7
作者 肖莲珍 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第5期983-989,共7页
The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity method.The experiments were carried out on the cement pastes with different water-c... The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity method.The experiments were carried out on the cement pastes with different water-cement ratios at different curing temperatures.The results show that the application of the maturity method has limitation to obtain the strength.It is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the mixes.The hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be reached.The relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity equation.The relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio. 展开更多
关键词 electrical resistivity cement hydration compressive strength maturity method
下载PDF
A Comprehensive Overview of the ELECTRE Method in Multi-Criteria Decision-Making 被引量:1
8
作者 Hamed Taherdoost Mitra Madanchian 《Journal of Management Science & Engineering Research》 2023年第2期5-16,共12页
The ELECTRE(ELimination Et Choix Traduisant la REalite)method has gained widespread recognition as one of the most effective multi-criteria decision-making(MCDM)methods.Its versatility allows it to be applied in a wid... The ELECTRE(ELimination Et Choix Traduisant la REalite)method has gained widespread recognition as one of the most effective multi-criteria decision-making(MCDM)methods.Its versatility allows it to be applied in a wide range of areas such as engineering,economics,business,environmental management and many others.This paper aims to provide an overview of the ELECTRE method,including its fundamental concepts,applications,advantages,and limitations.At its core,the ELECTRE method is an outranking family of MCDM techniques,which allows for the direct comparison of alternatives based on a set of criteria.The method takes into account the preferences and importance of decision-makers and generates a ranking of the alternatives based on their relative strengths and weaknesses.The ELECTRE method is a powerful tool for decision-making,and its applicability to a wide range of fields demonstrates its versatility and adaptability.By understanding its concepts,applications,merits,and demerits,decision-makers can use the ELECTRE method to make informed and effective decisions in a variety of contexts. 展开更多
关键词 Decision making Multi criteria decision making electrE method ELimination Et Choix Traduisant la REalite method Multi attribute decision making
下载PDF
Reconstruction of electrical capacitance tomography images based on fast linearized alternating direction method of multipliers for two-phase flow system 被引量:4
9
作者 Chongkun Xia Chengli Su +1 位作者 Jiangtao Cao Ping Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第5期597-605,共9页
Electrical capacitance tomography(ECT)has been applied to two-phase flow measurement in recent years.Image reconstruction algorithms play an important role in the successful applications of ECT.To solve the ill-posed ... Electrical capacitance tomography(ECT)has been applied to two-phase flow measurement in recent years.Image reconstruction algorithms play an important role in the successful applications of ECT.To solve the ill-posed and nonlinear inverse problem of ECT image reconstruction,a new ECT image reconstruction method based on fast linearized alternating direction method of multipliers(FLADMM)is proposed in this paper.On the basis of theoretical analysis of compressed sensing(CS),the data acquisition of ECT is regarded as a linear measurement process of permittivity distribution signal of pipe section.A new measurement matrix is designed and L1 regularization method is used to convert ECT inverse problem to a convex relaxation problem which contains prior knowledge.A new fast alternating direction method of multipliers which contained linearized idea is employed to minimize the objective function.Simulation data and experimental results indicate that compared with other methods,the quality and speed of reconstructed images are markedly improved.Also,the dynamic experimental results indicate that the proposed algorithm can ful fill the real-time requirement of ECT systems in the application. 展开更多
关键词 electrical capacitance tomography Image reconstruction Compressed sensing Alternating direction method of multipliers Two-phase flow
下载PDF
Nonlinear analysis on electrical properties in a bended composite piezoelectric semiconductor beam
10
作者 Luke ZHAO Feng JIN +1 位作者 Zhushan SHAO Wenjun WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2039-2056,共18页
In this paper,the interactions between the transverse loads and the electrical field quantities are investigated based on the nonlinear constitutive relation.By considering a composite beam consisting of a piezoelectr... In this paper,the interactions between the transverse loads and the electrical field quantities are investigated based on the nonlinear constitutive relation.By considering a composite beam consisting of a piezoelectric semiconductor and elastic layers,the nonlinear model is established based on the phenomenological theory and Euler’s beam theory.Furthermore,an iteration procedure based on the differential quadrature method(DQM)is developed to solve the nonlinear governing equations.Before analysis,the convergence and correctness are surveyed.It is found that the convergence of the proposed iteration is fast.Then,the transverse pressure induced electrical field quantities are investigated in detail.From the calculated results,it can be found that the consideration of nonlinear constitutive relation is necessary for a beam undergoing a large load.Compared with the linear results,the consideration of the nonlinear constitutive relation breaks the symmetry for the electric potential,the electric field,and the perturbation carrier density,and has little influence on the electric displacement.Furthermore,the non-uniform pressures are considered.The results show that the distributions of the electric field quantities are sensitively altered.It indicates that the electrical properties can be manipulated with the design of different transverse loads.The conclusions in this paper could be the guidance on designing and manufacturing electronic devices accurately. 展开更多
关键词 nonlinear constitutive relation electrical property composite piezoelectric semiconductor beam differential quadrature method(DQM) ITERATION
下载PDF
Simulation of electrically driven jet using Chebyshev collocation method 被引量:1
11
作者 Yan Liu,~(a)) and Ruojing Zhang~(b)) School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China 《Theoretical & Applied Mechanics Letters》 CAS 2011年第3期18-22,共5页
The model of electrically driven jet is governed by a series of quasi 1D dimensionless partial differential equations(PDEs).Following the method of lines,the Chebyshev collocation method is employed to discretize the ... The model of electrically driven jet is governed by a series of quasi 1D dimensionless partial differential equations(PDEs).Following the method of lines,the Chebyshev collocation method is employed to discretize the PDEs and obtain a system of differential-algebraic equations(DAEs).By differentiating constrains in DAEs twice,the system is transformed into a set of ordinary differential equations(ODEs) with invariants.Then the implicit differential equations solver 'ddaskr' is used to solve the ODEs and post-stabilization is executed at the end of each step.Results show the distributions of radius,linear charge density,stretching ratio and also the horizontal velocity at a time point.Meanwhile,the spiral and expanding projections to X-Y plane of the jet centerline suggest the occurring of bending instability. 展开更多
关键词 electrically driven jet method of lines Chebyshev collocation method differential-algebraic equation bending instability
下载PDF
Obtaining 2D Soil Resistance Profiles from the Integration of Electrical Resistivity Data and Standard Penetration Test (SPT) and Light Dynamic Penetrometer (DPL) Resistance Tests—Applications in Mass Movements Studies
12
作者 Cassiano Antonio Bortolozo Tatiana Sussel Gonçalves Mendes +10 位作者 Mariana Ferreira Benessiuti Motta Silvio Jorge Coelho Simões Tristan Pryer Daniel Metodiev Marcio Roberto Magalhães de Andrade Maiconn Vinicius de Moraes Danielle Silva de Paula Nélio José Bastos Luana Albertani Pampuch Rodolfo Moreda Mendes Marcio Augusto Ernesto de Moraes 《International Journal of Geosciences》 2023年第9期840-854,共15页
In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occ... In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies. 展开更多
关键词 GEOPHYSICS Geotechnical Data electrical Resistivity method Standard Penetration Test (SPT) Light Dynamic Penetrometer (DPL) Mass Movements
下载PDF
Probing the electric double layer structure at nitrogen-doped graphite electrodes by constant-potential molecular dynamics simulations
13
作者 Legeng Yu Nan Yao +5 位作者 Yu-Chen Gao Zhong-Heng Fu Bo Jiang Ruiping Li Cheng Tang Xiang Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期299-305,I0008,共8页
Electric double layer(EDL)is a critical topic in electrochemistry and largely determines the working performance of lithium batteries.However,atomic insights into the EDL structures on heteroatom-modified graphite ano... Electric double layer(EDL)is a critical topic in electrochemistry and largely determines the working performance of lithium batteries.However,atomic insights into the EDL structures on heteroatom-modified graphite anodes and EDL evolution with electrode potential are very lacking.Herein,a constant-potential molecular dynamics(CPMD)method is proposed to probe the EDL structure under working conditions,taking N-doped graphite electrodes and carbonate electrolytes as an example.An interface model was developed,incorporating the electrode potential and atom electronegativities.As a result,an insightful atomic scenario for the EDL structure under varied electrode potentials has been established,which unveils the important role of doping sites in regulating both the EDL structures and the following electrochemical reactions at the atomic level.Specifically,the negatively charged N atoms repel the anions and adsorb Li~+at high and low potentials,respectively.Such preferential adsorption suggests that Ndoped graphite can promote Li~+desolvation and regulate the location of Li~+deposition.This CPMD method not only unveils the mysterious function of N-doping from the viewpoint of EDL at the atomic level but also applies to probe the interfacial structure on other complicated electrodes. 展开更多
关键词 Lithium batteries Graphite N-DOPING electric double layer Molecular dynamics Constant potential method electrode potential
下载PDF
Scale Effects and a Method for Similarity Evaluation in Micro Electrical Discharge Machining
14
作者 LIU Qingyu ZHANG Qinhe +3 位作者 WANG Kan ZHU Guang FU Xiuzhuo ZHANG Jianhua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第6期1193-1199,共7页
Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at th... Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of "scale effects" in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM. 展开更多
关键词 electrical Discharge Machining (EDM) micro EDM Scale effect Similarity theory Similarity evaluating method
下载PDF
Electrical Impedance Tomography Based on Direct Search Method
15
作者 蔡畅 严壮志 《Journal of Shanghai University(English Edition)》 CAS 2005年第5期432-436,共5页
Solution to impedance distribution in electrical impedance tomography (EIT) is an ill-posed nonlinear inverse problem. It is especially difficult to reconstruct an EIT image in the center area of a measured object. ... Solution to impedance distribution in electrical impedance tomography (EIT) is an ill-posed nonlinear inverse problem. It is especially difficult to reconstruct an EIT image in the center area of a measured object. Tikhonov regularization with some prior information is a sound regnlarization method for static electrical impedance tomography under the condition that some true impedance distribution information is known a priori. This paper presents a direct search method (DSM) as pretreatment of image reconstruction through which one not only can construct a regularization matrix which may locate in areas of impedance change, but also can obtain an initial impedance distribution more similar to the true impedance distribution, as well as better current modes which can better distinguish the initial distribution and the true distribution. Simulation results indicate that, by using DSM, resolution in the center area of the measured object can be improved significantly. 展开更多
关键词 direct searching method (DSM) electrical impedance tomography (EIT) inverse problem.
下载PDF
Simulation Monitoring for Rainfall Infiltration in Soil Based on High Density Electrical Method
16
作者 Shanshan Lv Dengke He 《Journal of Geoscience and Environment Protection》 2021年第5期1-7,共7页
<div style="text-align:justify;"> Rainfall infiltration is a porous medium flow problem with variable saturation. Based on the theoretical analysis of the flow field, electrical conductivity of rocks, ... <div style="text-align:justify;"> Rainfall infiltration is a porous medium flow problem with variable saturation. Based on the theoretical analysis of the flow field, electrical conductivity of rocks, the electrical field, the paper simulates the coupling relationship between the water saturation in soil and the apparent resistivity distribution. It combines the Richards equation, the Archie formula and the Laplace equation. The experiment simulates the potential field data by the Wenner setting in electrical exploration on a two-layer geologic model with continuous rainfall during 5 days, which shows that the effective saturation in soil is increasing with the rainfall time, while the apparent resistivity is decreasing. This can provide a theoretical basis for the analyzing the rainfall infiltration and porosity of the soil by using high-density electrical method in the future. </div> 展开更多
关键词 Rainfall Infiltration Multi Physical Field Coupling Numerical Simulation High Density electrical method
下载PDF
Electrical Transport Properties of Type-Ⅷ Sn-Based Single-Crystalline Clathrates (Eu/Ba)8Ga16Sn30 Prepared by Ga Flux Method
17
作者 邓书平 程峰 +6 位作者 李德聪 唐语 陈钟 申兰先 刘虹霞 杨培志 邓书康 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期92-96,共5页
Single-crystalline samples of Eu/Ba-filled Sn-based type-Ⅷ clathrate are prepared by the Ga flux method with different stoichiometric ratios. The electrical transport properties of the samples are optimized by Eu dop... Single-crystalline samples of Eu/Ba-filled Sn-based type-Ⅷ clathrate are prepared by the Ga flux method with different stoichiometric ratios. The electrical transport properties of the samples are optimized by Eu doping. Results indicate that Eu atoms tend to replace Ba atoms. With the increase of the Eu initial content, the carrier density increases and the carrier mobility decreases, which leads to an increase of the Seebeck coefficient. By contrast, the electrical conductivity decreases. Finally, the sample with Eu initial content of x = 0.75 behaves with excellent electrical properties, which shows a maximal power factor of 1.51 mW·m^-1K^-2 at 480K, and the highest ZT achieved is 0.87 near the temperature of 483K. 展开更多
关键词 Seebeck Eu/Ba electrical Transport Properties of Type Prepared by Ga Flux method Sn-Based Single-Crystalline Clathrates BA GA
下载PDF
Thermal stability and electrical transport properties of Ge/Sn-codoped single crystalline β-Zn4Sb3 prepared by the Sn-flux method
18
作者 刘虹霞 邓书平 +2 位作者 李德聪 申兰先 邓书康 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期441-445,共5页
This study prepares a group of single crystalline β-Zn_4Sb_3 with Ge and Sn codoped by the Sn-flux method according to the nominal stoichiometric ratios of Zn_(4.4)Sb_3 Ge_xSn_3(x = 0–0.15). The prepared samples... This study prepares a group of single crystalline β-Zn_4Sb_3 with Ge and Sn codoped by the Sn-flux method according to the nominal stoichiometric ratios of Zn_(4.4)Sb_3 Ge_xSn_3(x = 0–0.15). The prepared samples possess a metallic luster surface with perfect appearance and large crystal sizes. The microscopic cracks or defects are invisible in the samples from the back-scattered electron image. Except for the heavily Ge-doped sample of x = 0.15, all the samples are single phase with space group R3c. The thermal analysis results show that the samples doped with Ge exhibit an excellent thermal stability.Compared with the polycrystalline Ge-substituted β-Zn_4Sb_3, the present single crystals have higher carrier mobility, and hence the electrical conductivity is improved, which reaches 7.48×10~4S·m^(-1) at room temperature for the x = 0.1 sample.The change of Ge and Sn contents does not improve the Seebeck coefficient significantly. Benefiting from the increased electrical conductivity, the sample with x = 0.075 gets the highest power factor of 1.45×10^(-3)W·m^(-1)·K^(-2) at 543 K. 展开更多
关键词 thermoelectric materials β-Zn4Sb3 flux method electrical transport properties
下载PDF
Application effect of high-density electrical method on detecting artificial filling layer: A case study of Chengjiangshan area of Huaibei City
19
作者 LI Shuai LIU Lijia +2 位作者 JIA Xiaodong LI Zhuoyang HAN Jiangtao 《Global Geology》 2022年第3期174-181,共8页
High-density electrical method has been proved to be an effective method for probing shallow sedimentary layers.It is principally used to identify the boundary between the Quaternary soil layer and bedrock according t... High-density electrical method has been proved to be an effective method for probing shallow sedimentary layers.It is principally used to identify the boundary between the Quaternary soil layer and bedrock according to the vertical change of apparent resistivity.However,the artificial filling layer has the characteristics of heterogeneity and high porosity,which makes it challenging to detect the artificial filling layer by high-density electrical method.The key to solve this problem is to detect the difference of conductivity between the filling layer and the underlying bedrock.This paper takes the land in Chengjiangshan area of Huaibei City,Anhui Province as the detection target.On the basis of fully analyzing the physical properties of the artificial filling layer,two-dimensional high-density electrical survey and inversion are used to define the thickness of the artificial filling layer.The research shows that the highdensity resistivity method has obvious advantages in delineating the distribution of bedrock and the thickness of the filling layer,and the reliability of the high-density electrical method in the detection of the artificial filling layer,and delineates the scope of the filling layer is verified by the borehole data. 展开更多
关键词 high-density resistivity method filling layer electrical structure 2D inversion
下载PDF
Research on Visual Operation and Guide System of Railway Four⁃electric Engineering Construction
20
作者 PANG Zhining XU Tianyi +1 位作者 WU Xusheng JIN Wenxin 《International Journal of Plant Engineering and Management》 2024年第1期47-54,共8页
The visualization operation of railway four-electric engineering construction is an important part in railway′s construction,which plays a critical role in improving operation efficiency and it is smoothly finished o... The visualization operation of railway four-electric engineering construction is an important part in railway′s construction,which plays a critical role in improving operation efficiency and it is smoothly finished on railway four-electric majors′professional construction.According to the typical high-speed railway project construction′s technology,these four-electric professional construction′s technology scheme are made into construction method′s video,according to the technology plan′s characteristics of professional,visualization and information,under the premise of improving the efficiency about professional project management and construction of the railway four-electric project,the critical technology problems of railway four-electric project are solved.At the same time,it also improves efficiency of BIM model′s construction,the cooperation management′s efficiency of construction process,and the ability of integrating model information. 展开更多
关键词 four electric PLATFORM BIM RAILWAY process method
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部