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Computational Water, Energy, and Environmental Engineering 2017年第3期6卷 304-319页

作者： Seidou Kane Soussou Sambou Issa Leye Raymond Diedhiou Seni Tamba Mouhamed Talla Cisse Didier Maria Ndione Mousse Landing Sane Faculty of Sciences and Technics Department of Physics Cheikh Anta Diop University Dakar Senegal polytechnic high school of thies Thies Senegal

Open channel junctions are encountered in urban water treatment plants, irrigation and drainage canals, and natural river systems. Junctions are very important in municipal sewerage systems and river engineering. Adequate theoretical description of flow through an open channel junction is difficult because numerous variables are to be considered. Equations of junction models are based on mass and momentum or mass and energy conservation. The objective of this study is to compare two junction models for subcritical flows. In channel branches, we solve numerically the Saint-Venant hyperbolic system by combining Preissmann scheme and double sweep method. We validate our results with HEC-RAS using Nash and Sutcliffe efficiency. In junction models, equality of water stage and complete energy conservation equation from HEC-RAS are compared. Outcome of the research clearly indicates that the complete conservation energy model is more suitable in flow through junction than equality of water stage model in serious situations.

关键词： Junction Model HEC RAS Saint-Venant’s Equations Double Sweep Method Equality of Water Stages Energy Conservation Modelling of Flow

Spontaneous Orientation Polarization of Anisotropic Equivalent Dipoles Harnessed by Entropy Engineering for Ultra‑Thin Electromagnetic Wave Absorber

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Nano-Micro Letters 2025年第1期17卷 424-438页

作者： Honghan Wang Xinyu Xiao Shangru Zhai Chuang Xue Guangping Zheng Deqing Zhang Renchao Che Junye Cheng Liaoning Key Lab of Lignocellulose Chemistry and BioMaterials Liaoning Collaborative Innovation Center for Lignocellulosic BiorefinerySchool of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian 116034People’s Republic of China school of Life Science and Biotechnology Dalian University of TechnologyDalian 116024People’s Republic of China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China school of Materials Science and Engineering Qiqihar UniversityQiqihar 161006People’s Republic of China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Department of Materials Science Shenzhen MSU-BIT UniversityShenzhen 517182People’s Republic of China

The synthesis of carbon supporter/nanoscale high-entropy alloys(HEAs)electromagnetic response composites by carbothermal shock method has been identified as an advanced strategy for the collaborative competition engineering of conductive/dielectric *** migration modes within HEAs as manipulated by the electronegativity,valence electron configurations and molar proportions of constituent elements determine the steady state and efficiency of equivalent ***,enlightened by skin-like effect,a reformative carbothermal shock method using carbonized cellulose paper(CCP)as carbon supporter is used to preserve the oxygencontaining functional groups(O·)of carbonized cellulose fibers(CCF).Nucleation of HEAs and construction of emblematic shell-core CCF/HEAs heterointerfaces are inextricably linked to carbon metabolism induced by O·.Meanwhile,the electron migration mode of switchable electronrich sites promotes the orientation polarization of anisotropic equivalent *** virtue of the reinforcement strategy,CCP/HEAs composite prepared by 35%molar ratio of Mn element(CCP/HEAs-Mn_(2.15))achieves efficient electromagnetic wave(EMW)absorption of−51.35 dB at an ultra-thin thickness of 1.03 *** mechanisms of the resulting dielectric properties of HEAs-based EMW absorbing materials are elucidated by combining theoretical calculations with experimental characterizations,which provide theoretical bases and feasible strategies for the simulation and practical application of electromagnetic functional devices(e.g.,ultra-wideband bandpass filter).

关键词： high-entropy alloys Carbothermal shock Switchable electron migration modes Emblematic shell-core heterointerfaces Ultra-thin thickness

The properties of GaMnN films grown by metalorganic chemical vapour deposition using Raman spectroscopy

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Chinese Physics B 2012年第7期21卷 513-517页

作者：邢海英牛萍娟谢玉芯 school of Electronics and Information Engineering Tianjin polytechnic University Engineering Research Center of high Power Solid State Lighting Application System school of Electrical Engineering&Automation Tianjin polytechnic University

An investigation of room-temperature Raman scattering is carried out on ferromagnetic semiconductor GaMnN films grown by metalorganic chemical vapour deposition with different Mn content values. New bands around 300 and 669 cm-1, that are not observed in undoped GaN, are found. They are assigned to disorder-activated mode and local vibration mode （LYM）, respectively. After annealing, the intensity ratio between the LVM and E2（high） mode, i.e., ILVM/IE2 （high）, increases. The LO phonon-plasmon coupled （LOPC） mode is found in GaMnN, and the frequency of the LOPC mode of GaMnN shifting toward higher side is observed with the increase in the Mn doping in GaN. The ferromagnetic character and the carrier density of our GaMnN sample are discussed.

关键词： diluted magnetic semiconductor metalorganic chemical vapour deposition Ram^n scat-tering

Carbon dioxide adsorption of two-dimensional carbide MXenes

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Journal of Advanced Ceramics 2018年第3期7卷 237-245页

作者： Bingxin WANG Aiguo ZHOU Fanfan LIU Jianliang CAO Libo WANG Qianku HU school of Materials Science and Engineering Henan Polytechnic University Henan International Joint Research Laboratory for high-Performance Light Metallic Materials and Numerical Simulations Henan Polytechnic University school of Chemistry and Chemical Engineering Henan Polytechnic University

Two-dimensional carbide MXenes(Ti_3C_2T_x and V_2CT_x)were prepared by exfoliating MAX phases(Ti_3AlC_2 and V_2AlC)powders in the solution of sodium fluoride(NaF)and hydrochloric acid(HCl).The specific surface area(SSA)of as-prepared Ti_3C_2T_x was 21 m^2/g,and that of V_2CT_x was 9 m^2/*** intercalation with dimethylsulfoxide,the SSA of Ti_3C_2T_x was increased to 66 m^2/g;that of V_2CT_x was increased to 19 m^2/*** adsorption properties on carbon dioxide(CO_2)were investigated under 0–4 MPa at room temperature(298 K).Intercalated Ti_3C_2T_x had the adsorption capacity of 5.79 mmol/g,which is close to the capacity of many common *** theoretical capacity of Ti_3C_2T_x with the SSA of 496 m^2/g was up to 44.2 mmol/***,due to high pack density,MXenes had very high volume-uptake *** capacity of intercalated Ti_3C_2T_(x )measured in this paper was 502 V·v^(–1).This value is already higher than volume capacity of most known *** results suggest that MXenes have some advantage features to be researched as novel CO_2 capture materials.

关键词： MXenes specific surface area (SSA) adsorption carbon dioxide

Scale Effects and a Method for Similarity Evaluation in Micro Electrical Discharge Machining

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Chinese Journal of Mechanical Engineering 2016年第6期29卷 1193-1199页

作者： LIU Qingyu ZHANG Qinhe WANG Kan ZHU Guang FU Xiuzhuo ZHANG Jianhua Key Laboratory of high Efficiency and Clean Mechanical Manufacture of Ministry of Education School of Mechanical Engineering Shandong University school of Mechanical and Automotive Engineering Shandong Polytechnic University

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.

关键词： Electrical Discharge Machining (EDM) micro EDM Scale effect Similarity theory Similarity evaluating method

A new method to suppress high-order harmonics for a synchrotron radiation soft X-ray beamline

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Chinese Physics C 2015年第4期39卷 97-99页

作者：郭志英邢海英洪才浩唐坤韩勇陈栋梁赵屹东 Institute of high Energy Physics Chinese Academy of Sciences school of Electronics and Information Engineering Tianjin Polytechnic University

A feasible and convenient method is proposed to suppress higher-harmonics for a varied-line-spacing plane grating monochromator in the soft X-ray region. Related calculations and experiments demonstrate that decreasing the included angle slightly by changing the parameter of the exit arm length can significantly improve light purity. This method is suitable and has been used for experiments of detector calibration in beamline 4B7B at the Beijing Synchrotron Radiation Facility （BSRF）.

关键词： soft X-ray high-order harmonics detector calibration Monk-Gillieson monochromator synchrotronradiation

A new soft X-ray magnetic circular dichroism facility at the BSRF beamline 4B7B

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Chinese Physics C 2015年第4期39卷 100-104页

作者：郭志英洪才浩邢海英唐坤郑雷徐伟陈栋梁崔明启赵屹东 Institute of high Energy Physics Chinese Academy of Sciences school of Electronics and Information Engineering Tianjin Polytechnic University

X-ray magnetic circular dichroism （XMCD） has become an important and powerful tool because it allows the study of material properties in combination with elemental specificity, chemical state specificity, and magnetic specificity. A new soft X-ray magnetic circular dichroism apparatus has been developed at the Beijing Synchrotron Radiation Facility （BSRF）. The apparatus combines three experimental conditions： an ultra-high-vacuum environ- ment, moderate magnetic fields and in-situ sample preparation to measure the absorption signal. We designed a C-type dipole electromagnet that provides magnetic fields up to 0.5 T in parallel （or anti-parallel） direction rela- tive to the incoming X-ray beam. The performances of the electromagnet are measured and the results show good agreement with the simulation ones. Following film grown in situ by evaporation methods, XMCD measurements are performed. Combined polarization corrections, the magnetic moments of the Fe and Co films determined by sum rules are consistent with other theoretical predictions and experimental measurements.

关键词： X-ray magnetic circular dichroism (XMCD) sum rule synchrotron radiation (SR) electromagnet polarization

Microstructures and Tensile Properties of Hot-extruded Mg-6Zn-xCe(x=0,0.6,1.0,2.0) Alloys

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Journal of Wuhan University of Technology(Materials Science) 2019年第1期34卷 150-155页

作者： YU Heshuai YANG Wenpeng school of Materials Science and Engineering Henan Polytechnic University Henan International Joint Research Laboratory for high-Performance Light Metallic Materials and Numerical Simulations Henan Polytechnic University

Mg-6Zn-x Ce(x = 0, 0.6, 1.0, 2.0) alloy ingots with diameter of 50 mm were extruded into bars with diameter of 12 mm at 300 ℃. The microstructures were analyzed by X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy, and mechanical properties were tested at room temperature. The results showed that major intermetallic composition in as-cast Mg-6Zn and Mg-6Zn-0.6Ce alloys was Mg_4Zn_7 phase, during extrusion Mg_4Zn_7 phase was dissolved into matrix and then precipitated as MgZn_2. In as-cast and as-extruded Mg-6Zn-1Ce and Mg-6Zn-2Ce alloys the major intermetallic composition was T phase. The microstructure of as-extruded alloy was refined due to complete dynamic recrystallization, the average grain size decreased with increasing Ce content, which were 12.1, 11.7, 11.0 and 10.0 mm, respectively. high density MgZn_2 precipitated in Mg-6Zn and Mg-6Zn-0.6Ce alloys. The broken T phase particles were distributed linearly along extrusion direction. Mg-6Zn-0.6Ce alloy exhibited a high yield strength of 226.3 MPa that was about 24 MPa higher than Mg-6Zn alloy. However, with increasing Ce contents, the strengths were decreased slightly because the effects of precipitation strengthening of MgZn_2 and solid solute strengthening of Zn were weakened though the strengthening effect of T phase was enhanced.

关键词： magnesium alloy extrusion microstructure mechanical properties

Current and Voltage Mode Resistorless Universal Biquad Filter Using a Single CCCDTA

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Chinese Journal of Electronics 2018年第6期27卷 1250-1257页

作者： LIN Shaojiang ZUO Xiaohua DENG Xiangyi school of Mechanic and Electric Engineering Hubei Polytechnic University school of Chemistry and Chemical Engineering Hubei Polytechnic University

Current mode(CM) Single-input and multi-output(SIMO) and Voltage mode(VM) Multi-input and single-output(MISO) biquad filters are proposed. The presented configurations use one Current controlled current differencing transconductance amplifier(CCCDTA)and two capacitors without any external resistors, which is easy suited for integrated circuit fabrication. The currentmode filter can realize the second-order low pass, band pass, high pass and band stop responses *** the voltage-mode filter can realize all the standard filtering functions from the same structure. The natural frequency(ω) and quality factor(Q) of the filters can be controlled electronically by transconductance of the CCCDTA. Moreover, the proposed filters does not require any impedance matching due to its two input resistance can be independently tuned through the diverse external bias currents of CCCDTA. The influences of the CCCDTA non-idealities are also analyzed and both the active and passive sensitivities are considerably low. This design was simulated in PSPICE. Simulation results showed that their performances in power, bandwidth, out-band rejection and in-band ripple are better than the traditional. Additionally,the experiment results are provided in the paper.

关键词： Current-mode filter Voltage-mode filter CCCDTA Analog signal processing

Statistical Analysis for Assessing Randomness, Shift and Trend in Rainfall Time Series under Climate Variability and Change: Case of Senegal

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Journal of Geoscience and Environment Protection 2017年第13期5卷 31-53页

作者： Didier Maria Ndione Soussou Sambou Moussé Landing Sane Seydou Kane Issa Leye Seni Tamba Mouhamed Talla Cisse Hydraulic and Fluids Mechanics Laboratory (HFML) Department of Physics Faculty of Sciences and technology Cheikh Anta Diop University (UCAD) Dakar Senegal polytechnic high school of thies Thies Senegal

The main purpose of this study is to assess the climate variability and change through statistical processing tools that able to highlight annual and monthly rainfall behavior between 1970 and 2010 in six strategical raingauges located in northern (Saint-Louis, Bakel), central (Dakar, Kaolack), and southern (Ziguinchor, Tambacounda) part of Senegal. Further, differences in sensitivity of statistical tests are also exhibited by applying several tests rather than a single one to check for one behavior. Dependency of results from statistical tests on studied sequence in time series is also shown comparing results of tests applied on two different periods (1970-2010 and 1960-2010). Therefore, between 1970 and 2010, exploratory data analysis is made to give in a visible manner a first idea on rainfall behavior. Then, Statistical characteristics such as the mean, variance, standard deviation, coefficient of variation, skewness and kurtosis are calculated. Subsequently, statistical tests are applied to all retained time series. Kendall and Spearman rank correlation tests allow verifying whether or not annual rainfall observations are independent. Hubert’s procedures of segmentation, Pettitt, Lee Heghinian and Buishand tests allow checking rainfall homogeneity. Trend is undertaken by first employing the annual and seasonal Mann-Kendall trend test, and in case of significance, magnitude of trend is calculated by Sen’s slope estimator tests. All statistical tests are applied in the period of 1960-2010. Explanatory analysis data indicates upwards trends for records in northern and central and trend free for southern records. Application of multiple tests shows that the Kendall and spearman ranks correlation tests lead to same conclusion. The difference in tests sensitivity was shown by outcomes of homogeneity tests giving different results either in dates of the shift occurrence or in the significance of an eventual shift. A synthesis analysis of results of tests was carried o

关键词： Senegal Rainfall Time Series Test Independence Homogeneity Shift Trend