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International Journal of Mining Science and Technology 2019年第2期29卷 263-272页

作者： Xiaofei Guo Zhiqiang Zhao Xu Gao Xiangye Wu Nianjie Ma Faculty of Resource and Safety Engineering China University of Mining and Technology (Beijing) Department of Energy and Mineral Engineering The Pennsylvania State University University Park Institute of Mining Engineering Inner Mongolia University of Science and Technology

In the non-uniform stress field, the surrounding rock plastic zone of the circular roadway shows different shapes under the different confining pressure conditions. Based on the boundary shape characteristics of the plastic zone, the characteristic radii of the plastic zone were proposed, namely the horizontal,longitudinal and medial axis radii, which could reflect the plastic zone shapes characteristics and classify the sizes of the key parts. On the theoretical basis of elastic-plastic mechanics, analytical solutions for the characteristic radii were obtained by theoretical deduction, and the relationships between the characteristic radii and key influencing factors were analyzed. Finally, the evaluation criterion of the circular roadway surrounding rock plastic zone shapes, evaluation criterion of the location of potential hazards caused by the roadway surrounding rock and evaluation critical points of roadway dynamic disasters based on characteristic radii were proposed. This work could provide a theoretical basis for stability analysis of the surrounding rock, support design, and guide the prevention and control of dynamic roadway disasters.

关键词： Inhomogeneous stress field analytical solutions Characteristic radii Morphological identification Disaster area

A catalyst for integrating analytical biology,analytical chemistry, and engineering to improve drinking water safety: The groundbreaking work of Dr. Michael Plewa

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Journal of Environmental Sciences 2022年第7期34卷 6-9页

作者： Susan D.Richardson Department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

It is interesting how a random encounter can profoundly change your life. My random encounter was with a young graduate student from Michael Plewa’s laboratory. The location was the 1999 American Chemical Society (ACS) Conference, where, following his talk, this promising researcher was being unfairly criticized by a well-established scientist. I disagreed with this scientist’s criticism, and I encouraged the student how I thought his work was important.

关键词： breaking integrating analytical

analytical expressions of non-relativistic static multipole polarizabilities for hydrogen-like ions

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Chinese Physics B 2020年第4期29卷 218-225页

作者：梅雪松周挽平钟振祥乔豪学 School of Physics and Technology Wuhan UniversityWuhan 430072China Engineering and Technology College Hubei University of TechnologyWuhan 430068China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

analytical formulas for the static multipole polarizabilities of hydrogen-like ions are derived by using the analytical wave functions and the reduced Green function and by applying a numerical fitting procedure.Our results are then applied to the studies of blackbody radiation shifts to atomic energy levels at different temperatures.Our analytical results can be served as a benchmark for other theoretical methods.

关键词： polrizabilities analytical formula hydrogen-like ions

analytical solution for vertical site response analysis and its validation

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Earthquake Engineering and Engineering Vibration 2019年第1期18卷 53-60页

作者： Liu Junwei Zhang Xiao Cao Zewei Han Bo Yang Shizeng School of Civil Engineering Qingdao University of Technology School of Civil Engineering Shandong University Nantong Municipal Engineering Design Institute Co. Ltd. Huangdao Municipal Water Resources Bureau

Existing studies for site response analysis in geotechnical earthquake engineering have widely concentrated on the horizontal component of the ground motion. However, strong vertical ground motions have been repeatedly observed, resulting in significant vertical compression damage of engineering structures. Furthermore, for the seismic design of critical structures(e.g. large-scale dams and nuclear power plants), the ground motions in all three directions should be considered. Therefore, there is a need to investigate the site response subjected to the vertical component of the ground motion, especially for the seismic design of critical structures. Consequently, in this study, a numerical program for vertical site response analysis is proposed based on the commonly used analytical transfer function method. The proposed program is then validated against well-documented case studies obtained from the Japanese KiK-net(Kiban Kyoshin network) downhole array monitoring system. Results show that the response spectra at the ground surface are well predicted in the low frequency range(<5 Hz), while discrepancies are observed in the high frequency range. However, the high frequency discrepancies do not significantly affect the overall prediction accuracy, as the overall seismic response of geotechnical structures are usually dominated by low frequency vibrations. Furthermore, the limitations in the analysis are also discussed.

关键词： site response analysis vertical ground motions transfer function analytical solution

analytical Model of Temperature Field in Unsteady Stage of Friction Plug Welding

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第5期36卷 789-797页

作者： YAN Chongjing ZHENG Yongle College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China Shanghai Aircraft Design and Research Institute Shanghai 201206P.R.China

The temperature field in unsteady phase greatly affects the quality of friction plug welding(FPW).An analytical model is put forward to correlate the process parameters and the temperature field in unsteady phase of FPW.Applying the von Mises criterion for plastic deformation and linearizing the heat flux,the model is achieved by Laplace transformation.The predicated peak temperature and peak time agree with the experiment data,with errors of about 4%and 8%,of AA7075-T6 FPW.

关键词： friction plug welding(FPW) unsteady stage temperature field analytical model

Pesticides and trace elements in cannabis:analytical and environmental challenges and opportunities

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Journal of Environmental Sciences 2019年第11期31卷 82-93页

作者： Caley B.Craven Nicholas Wawryk Ping Jiang Zhongshan Liu Xing-Fang Li Department of Chemistry Faculty of Science University of Alberta Edmonton AB T6G 2G2 Canada Division of analytical and Environmental Toxicology Department of Laboratory Medicine and Pathology Faculty of Medicine and DentistryUniversity of Alberta Edmonton AB T6G 2G3 Canada

Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually.Canada has recently legalized cannabis use in October 2018,joining several states,in the United States of America (e.g.,Colorado,California,and Oregon) and a few other countries.A variety of cannabis products including dry flowers,edibles,and oil products are widely consumed.With high demand for cannabis products worldwide,the quality of cannabis and its related products has become a major concern for consumer safety.Various guidelines have been set by different countries to ensure the quality,safety,and efficacy of cannabis products.In general,these guidelines require control of contaminants including pesticides,toxic elements,mycotoxins,and pathogens,as well as residual solvents in regard to cannabis oil.Accordingly,appropriate analytical methods are required to determine these contaminants in cannabis products for quality control.In this review,we focus on the current analytical challenges and method development for detection of pesticides and toxic elements in cannabis to meet various guidelines.

关键词： Cannabis QA/QC Contaminants analytical testing Pesticides Heavy metals Regulations

Surface potential-based analytical model for InGaZnO thin-film transistors with independent dual-gates

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Chinese Physics B 2020年第4期29卷 415-419页

作者：何伊妮邓联文覃婷廖聪维罗衡黄生祥 School of Physics and Electronics Central South UniversityChangsha 410083China

An analytical drain current model on the basis of the surface potential is proposed for indium-gallium zinc oxide(InGaZnO)thin-film transistors(TFTs)with an independent dual-gate(IDG)structure.For a unified expression of carriers’distribution for the sub-threshold region and the conduction region,the concept of equivalent flat-band voltage and the Lambert W function are introduced to solve the Poisson equation,and to derive the potential distribution of the active layer.In addition,the regional integration approach is used to develop a compact analytical current-voltage model.Although only two fitting parameters are required,a good agreement is obtained between the calculated results by the proposed model and the simulation results by TCAD.The proposed current-voltage model is then implemented by using Verilog-A for SPICE simulations of a dual-gate InGaZnO TFT integrated inverter circuit.

关键词： analytical model independent dual-gate indium-gallium zinc oxide(InGaZnO) surface potential

A 3D analytical model for vortex velocity field based on spiral streamline pattern

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Water Science and Engineering 2019年第3期12卷 244-252页

作者： Maryam Azarpira Amir Reza Zarrati Department of Civil and Environmental Engineering Amirkabir University of Technology

Vortices that develop over intakes are a hazardous hydraulic phenomenon.In this study, a 3D model was developed to study the flow field in air-core vortices.This model is based on the spiral pattern of streamlines and the analytical solution of the momentum and continuity equations for deriving the three components of velocity.The model provides equations for free surface profiles and 3D patterns of the streamlines.Moreover, a new relationship was suggested for calculating effective viscosity and its distribution across the vortex flow field.The performance of the proposed analytical model was compared with existing experimental data and the results of previous analytical models.The outcomes indicated that the proposed model could predict characteristics of the vortex flow with good accuracy.

关键词： Air-core vortices analytical model Velocity distribution Spiral streamlines Free surface profile

Multi-faults diagnosis of rolling bearings via adaptive customization of flexible analytical wavelet bases

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Chinese Journal of Aeronautics 2020年第2期33卷 407-417页

作者： Chunlin ZHANG Yuling LIU Fangyi WAN Binqiang CHEN Jie LIU Bingbing HU School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China School of Management Northwestern Polytechnical UniversityXi’an 710072China School of Aerospace Engineering Xiamen UniversityXiamen 361005China Department of Mechanical and Aerospace Engineering Carleton UniversityOttawaON K1S5B6Canada Faculty of Printing Packing and Digital Media EngineeringXi’an University of TechnologyXi’an 710048China

Multi-faults detection is a challenge for rolling bearings due to the mode mixture and coupling of multiple fault features,as well as its easy burying in the complex,non-stationary structural vibrations and strong background noises.In this paper,a method based on the flexible analytical wavelet transform(FAWT)possessing fractional scaling and translation factors is proposed to identify multiple faults occurred in different components of rolling bearings.During the route of the proposed method,the proper FAWT bases are constructed via genetic optimization algorithm(GA)based on maximizing the spectral correlated kurtosis(SCK)which is firstly presented and proved to be efficient and effective in indicating interested fault mode.Via using the customized FAWT bases for each interested fault mode,the original vibration measurements are decomposed into fine frequency subbands,and the sensitive subband which enhances the signal-to-noise ratio(SNR)is selected to exhibit the fault signature on its envelope spectrum.The proposed method is tested via simulated signals,and applied to analyze the experimental vibration measurements from the running roller bearings subjected to outrace,inner-race and roller defects.The analysis results validate the effectiveness of the proposed method in identifying multi-faults occurred in different components of rolling bearings.

关键词： Bearing defect identification Fault diagnosis Flexible analytical wavelet transform Multiple faults Spectral correlated kurtosis

Detection and extraction of heavy metal ions using paper-based analytical devices fabricated via atom stamp printing

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Microsystems & Nanoengineering 2020年第1期6卷 1187-1198页

作者： Yanfang Guan Baichuan Sun School of Electromechanical Engineering Henan University of technologyZhengzhou 450001China

As a promising concept,microfluidic paper-based analytical devices(μPADs)have seen rapid development in recent years.In this study,a new method of fabricatingμPADs by atom stamp printing(ASP)is proposed and studied.The advantages of this new method compared to other methods include its low cost,ease of operation,high production efficiency,and high resolution(the minimum widths of the hydrophilic channels and hydrophobic barriers are 328 and 312μm,respectively).As a proof of concept,μPADs fabricated with the ASP method were used to detect different concentrations of Cu^(2+)via a colorimetric method.Moreover,combined with a distance-based detection method,these devices achieved a Cu^(2+)detection limit of down to 1mg/L.In addition,a new paper-based solid–liquid extraction device(PSED)based on a three-dimensional(3D)μPAD with a“3+2”structure and a recyclable extraction mode was developed.Specifically,using the characteristics of paper filtration and capillary force,the device completed multiple extraction and filtration steps from traditional solid–liquid extraction processes with high efficiency.The developed PSED platform allows the detection of heavy metal ions much more cheaply and simply and with a faster response time at the point of care,and it has great promise for applications in food safety and environmental pollution in resource-limited areas.

关键词： printing analytical faster