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Plasma Science and Technology 2019年第6期21卷 52-57页

作者： h j YEOM D h ChOI Y S LEE j h KIM D j SEONG S j YOU h C LEE Korea Research Institute of Standards and Science(KRISS) Daejeon 34113 Republic of Korea Department of Physics Chungnam National University Daejeon 34134 Republic of Korea

In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff *** measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 *** plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing *** decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this *** etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and *** was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).

关键词： remote plasma source electron density cutoff probe downstream etch

Optimal use of mobile cooling units in a deep-level gold mine

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International journal of Mining Science and Technology 2020年第4期30卷 547-553页

作者： h.j.van Staden j.F.van Rensburg h.j.Groenewald Centre for Research and Continued Engineering Development North-West UniversityPretoria 0081South Africa

The South African gold mining sector remains a significant contributor to the country’s *** several challenges that hinder the realisation of South Africa’s full mineral potential,the sector’s sustainability and profitability can be enhanced through implementing operational improvement *** cooling units(MCUs)were identified as a potential focus area for operational *** are used as tertiary or in-stope cooling in hot underground *** this paper,a method was presented to characterise the performance of existing MCUs based on three key performance indicators(KPIs),namely,the wet-bulb temperature ratio(WTR),efficiency and *** strategies were then elected and implemented based on these *** implementation of this method in a South African gold mine attained a reduction in pumped water volumes,reduced operating costs through electricity cost savings and improvements in underground ventilation air temperatures.

关键词： Mobile cooling units Optimisation Mine cooling performance Electricity cost savings Spot cooling

A structural topological optimization method for multi-displacement constraints and any initial topology configuration

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Acta Mechanica Sinica 2010年第5期26卷 735-744页

作者： j. h. Rong j. h. Yi School of Automotive and Mechanical Engineering Changsha University of Science and TechnologyChangsha 410076 China

In density-based topological design, one expects that the final result consists of elements either black （solid material） or white （void）, without any grey areas. Moreover, one also expects that the optimal topology can be obtained by starting from any initial topology configuration. An improved structural topological optimization method for multidisplacement constraints is proposed in this paper. In the proposed method, the whole optimization process is divided into two optimization adjustment phases and a phase transferring step. Firstly, an optimization model is built to deal with the varied displacement limits, design space adjustments, and reasonable relations between the element stiffness matrix and mass and its element topology variable. Secondly, a procedure is proposed to solve the optimization problem formulated in the first optimization adjustment phase, by starting with a small design space and advancing to a larger deign space. The design space adjustments are automatic when the design domain needs expansions, in which the convergence of the proposed method will not be affected. The final topology obtained by the proposed procedure in the first optimization phase, can approach to the vicinity of the optimum topology. Then, a heuristic algorithm is given to improve the efficiency and make the designed structural topology black/white in both the phase transferring step and the second optimization adjustment phase. And the optimum topology can finally be obtained by the second phase optimization adjustments. Two examples are presented to show that the topologies obtained by the proposed method are of very good 0/1 design distribution property, and the computational efficiency is enhanced by reducing the element number of the design structural finite model during two optimization adjustment phases. And the examples also show that this method is robust and practicable.

关键词： Topological optimization Displacement constraint Continuum structure Design space adjustment Rational approximation material model

双源光子计数冠状动脉CT血管成像中虚拟无碘冠状动脉钙化评分的可行性：一项动态体模研究

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国际医学放射学杂志 2025年第1期 118-119页

作者： M.M.Dobrolinska L.R.Koetzier M.j.W.Greuter R.Vliegenthart j.vander Bie N.h.j.Prakken 李晗

摘要目的旨在优化光子计数CT(PCCT)获取的冠状动脉CTA(CCTA)重建参数，用于冠状动脉钙化（CAC）评分；并将其与参考钙化评分CT(CSCT)扫描相比，评估基于CCTA

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Effects of the Reversely Rotating Assisted Shoulder on Microstructures During the Reverse Dual-rotation Friction Stir Welding

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journal of Materials Science & Technology 2015年第4期31卷 375-383页

作者： j.Q.Li h.j.Liu State Key Laboratory of Advanced Welding and joining Harbin Institute of Technology Capital Aerospace Machinery Company

The reverse dual-rotation friction stir welding(RDR-FSW) has the capability to adjust the heat generation because of the separately designed tool shoulder and tool *** welding torque exerted on the workpiece by the reversely rotating shoulder is opposite to that exerted by the rotating tool pin,so the total welding torque is reduced,which is beneficial to reducing the clamping requirement of *** the present paper,a RDR-FSW joint was welded in a condition similar to the optimal welding condition of conventional FSW,and microstructures in various zones were investigated by comparison,aiming to highlight effects of the reversely rotating assisted *** to the heat conduction of the middle cylinder and the bottom end cover on which the assisted shoulder was machined,the thermal effect of RDR-FSW was smaller than that of the conventional ***,the effect of assisted shoulder on the plastic flow or deformation of material or was constrained in a thin layer near the weld top surface,and thus the flow of material especially along the thickness direction was clearly decreased in the *** the heat-affected zone(hAZ),the precipitate coarsening was the main evolution and was completed through the dissolution of small precipitates and the continuous growth of large *** contrast,the dissolution degree of precipitates increased significantly in the thermomechanically affected zone(TMAZ),and a small amount of original meta-stable precipitates transformed to block-shaped stable *** evolutions in the shoulder affected zone(SAZ)and the weld nugget zone were similar,*** majority of original meta-stable precipitates dissolved into the matrix and the remainder transformed to stable precipitates,though the dissolution degree was greater in the *** with the conventional FSW joint,the coarsening degrees of precipitates in the hAZ and TMAZ of RDR-FSW joint were much smaller,as well as the dissolution degrees of p

关键词： Friction stir welding Reverse dual-rotation fricti

Computational study on influence of RF shielding box on inductance of coil

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Plasma Science and Technology 2019年第6期21卷 23-28页

作者： S j KIM j j LEE Y S LEE j h KIM S j YOU Applied Physics lab for PLasma Engineering(APPLE) Department of Physics Chungnam National University Daejeon 34134 Republic of Korea Korea Research Institute of Standards and Science(KRISS) Daejeon 34113 Republic of Korea

Despite the fact that a radio frequency (RF) shielding box affects a coil inductance used in matching network,RF engineers have used a coil inductance measured in open space on designing matching networks since it is difficult to precisely measure the coil inductance within the RF shielding *** this work,we investigate the influences of the RF shielding box on the coil inductance via a 3D full electromagnetic wave *** results shows that the coil inductance decreases from-6.0% to-11.9% compared with its ideal inductance depending on coil positions within the RF shielding *** inductive and capacitive coupling between the coil and surfaces of the RF shielding box contribute to the reduction of the coil *** expect that these results would be useful for those who design RF matching networks.

关键词： 3D full EM wave simulation RF matching component RF shield inductive and capacitive coupling

Thermoelastic Analysis of Non-uniform Pressurized Functionally Graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method

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Chinese journal of Mechanical Engineering 2015年第6期28卷 1149-1156页

作者： KhOShGOFTAR M j MIRZAALI M j RAhIMI G h Faculty of Mechanical Engineering Tarbiat Modares University Department of Mechanical Engineering Faculty of Engineering Arak University Department of Mechanical Engineering Politecnico di Milano

Recently application of functionally graded materials（FGMs） have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

关键词： non-homogenous cylinder First order Shear Deformation Theory matched asymptotic method perturbation method functionally graded material

Incremental forming of free surface with magnesium alloy AZ31 sheet at warm temperatures

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中国有色金属学会会刊：英文版 2008年第A01期18卷 165-169页

作者： Y.h.jI j.j.PARK Department of Mechanical and System Design Engineering Hongik University

The formabilityof AZ31 sheet begins to increase drastically at 150℃.The incremental forming technique was thus applied to AZ31 sheet at 150℃to utilize the formability to its fullest capacity at the lowest possible temperature for forming applications.A surface scanning technique was used followed by the tool path generation to incrementally form an egg *** thorough examination of various tool paths,the surface was most successfully produced by forming an intermediate shape followed by a series of tool *** scale stickers were devised to improve the accuracy in the measurement of grid deformation.

关键词：金属材料数控成形加工 AZ31镁合金板材

Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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journal of Rare Earths 2004年第z2期22卷 153-156页

作者： D h jung B Park j j Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

The FAST Galactic Plane Pulsar Snapshot Survey. Ⅵ. The Discovery of 473 New Pulsars

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Research in Astronomy and Astrophysics 2025年第1期 10-65页

作者： j.L.han D.j.Zhou C.Wang W.Q.Su Yi Yan W.C.jing Z.L.Yang P.F.Wang T.Wang j.Xu N.N.Cai j.h.Sun Q.L.Yang R.X.Xu h.G.Wang X.P.You National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences Department of Astronomy Peking University Kavli Institute for Astronomy and Astrophysics Peking University Department of Astronomy School of Physics and Materials Science Guangzhou University School of Physical Science and Technology Southwest University

The Five-hundred-meter Aperture Spherical radio Telescope （FAST） is the most sensitive telescope at the L-band（1.0–1.5 Ghz） and has been used to carry out the FAST Galactic Plane Pulsar Snapshot （GPPS） survey in the las5 *** to now,the survey has covered one-fourth of the planned areas within±10~ofrom the Galactic plane visible by FAST,and discovered 751 *** the first publication of the discovery of 201 pulsars and one rotating radio transient （RRAT） in 2021 and 76 RRATs in 2023,here we report the discovery of 473 new pulsars from the FAST GPPS survey,including 137 new millisecond pulsars and 30 new *** find 34 millisecond pulsars discovered by the GPPS survey which can be timed with a precision better than 3μs by using FAST15 minute observations and can be used for pulsar timing *** GPPS survey has discovered eight pulsars with periods greater than 10 s including one with 29.77 *** integrated profiles of pulsars and individual pulses of RRATs are *** the FAST GPPS survey,we also detected previously known pulsars and updated parameters for 52 *** addition,we discovered two fast radio bursts plus one probable case with high dispersion measures indicating their extragalactic origin.

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