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Effects of longwall-induced stress and deformation on the stability and mechanical integrity of shale gas wells drilled through a longwall abutment pillar

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International Journal of Mining Science and Technology 2017年第1期27卷 115-120页

作者： Daniel w.h.Su National Institute for Occupational Safety and health Bruceton 15236PAUSA

This paper presents the results of a comprehensive study conducted by CONSOL Energy, Marcellus Shale Coalition, and Pennsylvania Coal Association to evaluate the effects of longwall-induced subsurface deformations on the mechanical integrity of shale gas wells drilled over a longwall abutment *** primary objective is to demonstrate that a properly constructed gas well in a standard longwall abutment pillar can maintain mechanical integrity during and after mining operations. A study site was selected over a southwestern Pennsylvania coal mine, which extracts 457-m-wide longwall faces under about 183 m of cover. Four test wells and four monitoring wells were drilled and installed over a 38-m by84-m centers abutment pillar. In addition to the test wells and monitoring wells, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the 457-m-wide longwall panels on the south and north sides of the abutment pillar were mined by. To evaluate the resulting coal protection casing profile and lateral displacement, three separate 60-arm caliper surveys were conducted. This research represents a very important step and initiative to utilize the knowledge and science obtained from mining research to improve miner and public safety as well as the safety and health of the oil and gas industries.

关键词： Gas well Casing Abutment pillar Stability Safety and health Instrumentation Numerical simulation

Design, simulation and construction of the Taban tokamak

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Plasma Science and Technology 2018年第4期20卷 112-120页

作者： h r MIrZAEI r AMrOLLAhI Statistics of Department of Energy Engineering & Physics Amirkabir University of Tehran Tehran lran

This paper describes the design and construction of the Taban tokamak, which is located in Amirkabir University of Technology, Tehran, Iran. The Taban tokamak was designed for plasma investigation. The design, simulation and construction of essential parts of the Taban tokamak such as the toroidal field(TF) system, ohmic heating(Oh) system and equilibrium field system and their power supplies are presented. For the Taban tokamak, the toroidal magnetic coil was designed to produce a maximum field of 0.7 T at r?=?0.45 m. The power supply of the TF was a130 kJ, 0–10 kV capacitor bank. ripples of toroidal magnetic field at the plasma edge and plasma center are 0.2% and 0.014%, respectively. For the Oh system with 3 kA current, the stray field in the plasma region is less than 40 G over 80% of the plasma volume. The power supply of the Oh system consists of two stages, as follows. The fast bank stage is a 120 μF, 0–5 k V capacitor that produces 2.5 kA in 400 μs and the slow bank stage is 93 mF, 600 V that can produce a maximum of 3 kA. The equilibrium system can produce uniform magnetic field at plasma volume. This system’s power supply, like the Oh system, consists of two stages, so that the fast bank stage is 500 μF, 800 V and the slow bank stage is 110 mF, 200 V.

关键词： tokamak magnetic field equilibrium

SIMULATION OF ThE MAGNETIZATION rEVErSAL PrOCESS OF rECTANGLE-ShAPED NiFe FILM ELEMENTS UNDEr AN OrThOGONAL MAGNETIC FIELD

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Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 642-646页

作者： w.L. Zhang r.J. Tang w.X. Zhang B. Peng h. C. Jiang h.w. Zhang School of Microelectronics and Solid-state Electronics University of Electronic Science and Technology of China Chengdu 610054 China

The magnetization reversal process of nano-size rectangle-shaped NiFe film elements with different aspect ratios have been investigated under the orthogonally applied magnetic fields by micromagnetic simulation. Different magnetization reversal modes can appear depending on whether the bias field is applied or not. when there is no bias field, double “C” state is the initial reversal state. however, when there is a bias field, “S” state is the starting mode. The larger the aspect ratio is, the larger the switching field is. But, when the aspect ratio is larger than 3, the increase of the switching field ceases. These results can provide useful information to the application of the patterned NiFe film with rectangular elements.

关键词： NiFe film element micromagnetics aspect ratio magnetization reversal,switching field

Q-Switching Pulse Operation in 1.5-μm region Using Copper Nanoparticles as Saturable Absorber

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Chinese Physics Letters 2017年第3期34卷 41-44页

作者： A.r.Muhammad M.T.Ahmad r.Zakaria h.r.A.rahim S.F.A.Z.Yusoff K.S.hamdan h.h.M.Yusof h.Arof S.w.harun Department of Electrical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Photonics research Centre Physics DepartmentFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia

we demonstrate a passively Q-switched erbium-doped fiber laser （EDFL） using a copper nanoparticle （CuNP） thin film as the saturable absorber in a ring cavity. A stable Q-switched pulse operation is observed as the CuNP saturable absorber （SA） is introduced in the cavity. The pulse repetition rate of the EDFL is observed to be proportional to the pump power, and is limited to 101.2khz by the maximum pump power of 113.7mw. On the other hand, the pulse width reduces from 10.19μs to 4.28μs as the pump power is varied from 26.1 mw to 113.7mw. The findings suggest that CuNP SA could be useful as a potential saturable absorber for the development of the robust, compact, efficient and low cost Q-switched fiber laser operating at 1.5-μm region.

关键词： Cu m region Using Copper Nanoparticles as Saturable Absorber Q-Switching Pulse Operation in 1.5 SA khz EDF

Effect of solute atom concentration and precipitates on serrated flow in Mg-3Nd-Zn alloy

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Journal of Materials Science & Technology 2018年第7期34卷 1236-1242页

作者： w.h.wang D.wu r.S.Chen X.N.Zhang State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University The Group of Magnesium Alloys and Their Applications Institute of Metal Research Chinese Academy of Sciences

Influence of solute atom concentration and precipitates on serrated flow, i.e., Portevin-Le Chatelier effect, was studied in Mg-3Nd-Zn alloy by tensile test at 250℃ with a strain rate of l x 10^-3 s^-1 Microstructure and tensile property of the Mg-3Nd-Zn alloy in solution and aging conditions were also investigated. results indicate that the serrated flow was weakened with aging time, and geometry of the serrations changed from sharp to rounded corner. Through analyzing the mechanism of the interactions between dislocations and solute atoms, it was identified that the precipitates did not only weaken the serrated flow due to the decrease in the concentration of solute atom, but also regulate the serration type by restraining the movement of dislocations during high temperature deformation.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

关键词： Magnesium alloy Serrated flow Precipitate heat treatment Deformation behavior

The Voice of the Body:why AI Should Listen to It and an Archive

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Cyborg and Bionic Systems 2023年第1期4卷 520-522页

作者： Kun Qian Bin hu Yoshiharu yamamoto Bjorn w.Schuller School of Medical Technology Beijing Institute of TechnologyBeijing 100081China Educational Physiology Laboratory Graduate School of EducationThe University of TokyoTokyo 113-0033Japan GLAM—Group on Language Audio&MusicImperial College LondonLondon SW72AZUK Chair of Embedded Intelligence for health Care and wellbeing University of Augsburg86159 AugsburgGermany

The sound generated by body carries important information about our health status physically and *** the past decades,we have witnessed a plethora of successes achieved in the field of body sound ***,the fundamentals of this young field are still not well *** particular,publicly accessible databases are rarely developed,which dramatically restrains a sustainable *** this end,we are launching and continuously calling for participation from the global scientific community to contribute to the Voice of the Body(VoB)*** aim to build an open access platform to collect the well-established body sound databases in a well standardized ***,we hope to organize a series of challenges to promote the development of audio-driven methods for healthcare via the proposed *** believe that VoB can help break the walls between different subjects toward an era of Medicine 4.0 enriched by audio intelligence.

关键词： Voice sound restrain

Quantifying the Microstructures of Pure Cu Subjected to Dynamic Plastic Deformation at Cryogenic Temperature

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Journal of Materials Science & Technology 2011年第8期27卷 673-679页

作者： F. Yan h. w. Zhang N.r. Tao K. Lu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

A pure Cu （99.995 wt%） has been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Three types of microstructures that are related to dislocation slip, twinning and shear banding have been quantitatively characterized by transmission electron microscopy （TEM） assisted by convergent beam electron diffraction （CBED） analysis. Microstructures originated from dislocation slip inside or outside the shear bands are characterized by low angle boundaries （〈15°） that are spaced in the nanometer scale, whereas most deformation twins are deviated from the perfect ∑3 coincidence （60°/〈111〉） up to the maximum angle of 9°. The quantitative structural characteristics are compared with those in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of the flow stress-structural parameter relationship.

关键词： Quantitative structural characterization Cu Dynamic plastic deformation Trans mission electron microscopy Convergent beam electron diffraction

Shortening the Duration of heat Treatment in the Lower Bainitic range

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材料热处理学报 2004年第5期25卷 555-560页

作者： h. Vetters h.-w. Zoch Foundation Institute for Materials Science Bremen GermanyFoundation Institute for Materials Science Bremen Germany

In many cases an isothermal treatment of throughhardening bearing grades in the lower bainitic range allows to adjust the mechanical properties of machine components to the later application, similar to those of martensitic hardening. The achieved microstructure contains only a negligible amount of retained austenite, so a dimensional change of components during application can be reduced. One disadvantage of the isothermal bainitic treatment in salt bath is that the duration of the treatment is much longer than that of the martensitic hardening and this causes higher costs. Therefore it would be desirable to be able to shorten the transformation duration in the lower bainitic range. The aim of the present work is to determine the parameters, by which the process could be greatly shortened in comparison with the conventional transformation process in the lower bainitic range. Therefore the bainitic transformation behavior of the steel 100 Cr6 (SAE 52100) and the relevant influence factors were investigated by means of dilatometry, in which the heat treatments were carried out with different process variants including pre-quenching or post-quenching. The amount of retained austenite in the microstructure and the hardness of the steel after the shortened heat treatments were measured. Finally the possibility to use these processes in industrial production is discussed.

关键词：贝氏体轴承钢膨胀测定法热处理

Gorenstein Projective Modules over Triangular Matrix rings

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Algebra Colloquium 2016年第1期23卷 97-104页

作者： h. Eshraghi r. hafezi Sh. Salarian Z.w. Li Department of Pure Mathematics Faculty of Mathematical Sciences University of Kashan P.O. Box 87317-51167 Kashan Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5746 Tehran Iran Department of Mathematics University of Isfahan P.O. Box 81746-73441 Isfahan Iran School of Mathematics Institute for Research in Fundarnental Sciences (IPM) P.O. Box 19395-5746 Tehran Iran Department of Mathematics Jiangsu Normal University Xuzhou 221116 China

Let r and S be Artin algebras and F be their triangular matrix extension via a bimodule sMr. we study totally acyclic complexes of projective F-modules and obtain a complete description of Gorenstein projective F-modu... 详细信息

关键词： Gorenstein projective totally acyclic Cohen-Macaulay finite