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An Experimental Artificial Neural Network Model:Investigating and Predicting Effects of Quenching Process on Residual Stresses of AISI 1035 Steel Alloy
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作者 Salman Khayoon Aldriasawi Nihayat Hussein Ameen +3 位作者 Kareem Idan Fadheel Ashham Muhammed Anead Hakeem Emad Mhabes Barhm Mohamad 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第5期78-92,共15页
The present study establishes a new estimation model using an artificial neural network(ANN) to predict the mechanical properties of the AISI 1035 alloy.The experiments were designed based on the L16 orthogonal array ... The present study establishes a new estimation model using an artificial neural network(ANN) to predict the mechanical properties of the AISI 1035 alloy.The experiments were designed based on the L16 orthogonal array of the Taguchi method.A proposed numerical model for predicting the correlation of mechanical properties was supplemented with experimental data.The quenching process was conducted using a cooling medium called “nanofluids”.Nanoparticles were dissolved in a liquid phase at various concentrations(0.5%,1%,2.5%,and 5% vf) to prepare the nanofluids.Experimental investigations were done to assess the impact of temperature,base fluid,volume fraction,and soaking time on the mechanical properties.The outcomes showed that all conditions led to a noticeable improvement in the alloy's hardness which reached 100%,the grain size was refined about 80%,and unwanted residual stresses were removed from 50 to 150 MPa.Adding 5% of CuO nanoparticles to oil led to the best grain size refinement,while adding 2.5% of Al_(2)O_(3) nanoparticles to engine oil resulted in the greatest compressive residual stress.The experimental variables were used as the input data for the established numerical ANN model,and the mechanical properties were the output.Upwards of 99% of the training network's correlations seemed to be positive.The estimated result,nevertheless,matched the experimental dataset exactly.Thus,the ANN model is an effective tool for reflecting the effects of quenching conditions on the mechanical properties of AISI 1035. 展开更多
关键词 quenching nanofluids residual stresses steel alloy artificial neural network MANOVA
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Analysis of Quenching Resistor Effect to Improve Stability of TIA Circuit for APD-A Secondary Publication
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作者 Dong-Han Ki Yu-Rin Jin +1 位作者 Sung-Mi Kim Seong-Ik Cho 《Journal of Electronic Research and Application》 2024年第2期54-61,共8页
In this paper,since the Avalanche Photo Diode(APD)for Light-to-Voltage LTV conversion uses a high voltage in the operating range unlike other Photo Diodes(PD),the quenching resistor must be connected in series to prev... In this paper,since the Avalanche Photo Diode(APD)for Light-to-Voltage LTV conversion uses a high voltage in the operating range unlike other Photo Diodes(PD),the quenching resistor must be connected in series to prevent overcurrent when using the Transimpedance Amplifier(TIA).In such a case,quenching resistance may affect the transfer function of the TIA circuit,resulting in serious stability.Therefore,in this paper,by analyzing the effect of APD quenching resistance on the voltage and current loop transfer function of TIA,we proposed a loop analysis and a method for determining the quenching resistance value to improve stability.A TIA circuit with quenching resistance was designed by the proposed method and its operational stability was verified through simulation and chip fabrication. 展开更多
关键词 APD TIA quenching resistor STABILITY Transfer function
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Discussion on the Free Quenching Heat Treatment Process of Automotive Leaf Springs
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作者 Xianfeng Xu 《Frontiers of Metallurgical Industry》 2024年第1期9-11,共3页
Free quenching of automotive leaf springs is a new technology that has gradually started to be applied in the industry in China in recent years.Only a few manufacturers are applying it in the industry.Through more tha... Free quenching of automotive leaf springs is a new technology that has gradually started to be applied in the industry in China in recent years.Only a few manufacturers are applying it in the industry.Through more than half a year of on-site practice,the changes in the hot forming of spring plates before free quenching have been explored,and finally a heat treatment process that meets the production requirements of our company has been developed,achieving normal production. 展开更多
关键词 automotive leaf springs free quenching heat treatment TECHNOLOGY
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Influence of quenching medium on the dendrite morphology,hardness,and tribological behaviour of cast Cu-Ni-Sn spinodal alloy for defence application 被引量:1
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作者 Bipin Sankar Karthik V Shankar +4 位作者 Vamu Sunil Hemanth Kashyap S Nikhil Nair Adarsh A.Nair Abhinav P M 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第12期83-100,共18页
Cu-Ni-Sn spinodal alloys(Spinodal bronze)are potential materials with robust applications in components associated with defence applications like bearings,propellers,bushes,and shafts of heavily loaded aircraft,off-ro... Cu-Ni-Sn spinodal alloys(Spinodal bronze)are potential materials with robust applications in components associated with defence applications like bearings,propellers,bushes,and shafts of heavily loaded aircraft,off-road vehicles,and warships.This paper presents a comparative study using water,Brine solution,and SAE 40 oil as the quenching media in regular bronze(Cu-6Sn)and spinodal bronze(Cu-9Ni-6Sn)alloys.Morphological analysis was conducted by optical microscopy,transmission electron microscopy(TEM),and X-ray diffraction technique(XRD)on bronze and spinodal bronze samples immersed in the three different quenching media to understand the grain size and hardness values better.Tribological analysis was performed to analyze the effect of quenching media on the wear aspects of bronze and spinodal bronze samples.The hardness value of the brine-aged spinodal bronze samples was as high as 320 Hv,and the grain size was very low in the range of 60μm.A quantitative comparison between brine-aged regular bronze and brine-aged spinodal bronze showed that the hardness(Hv)was almost 80%higher for brine-aged spinodal bronze.Further,the grain size was approximately 30%finer for spinodal bronze when compared with regular bronze.When the load was increased in spinodal bronze samples,there was an initial dip in wear rate followed by a marginal increase.There was a steady increase in friction coefficient with a rise in load for brine-aged regular bronze and spinodal bronze samples.These results indicate that brine solution is the most effective quenching medium for cast Cu-Ni-Sn spinodal alloys. 展开更多
关键词 quenching Water BRINE SAE 40 oil Grain size HARDNESS Wear rate Spinodal decomposition CuSn Spinodal alloy CuNiSn
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Influence of two distinct quenching end-temperatures on phase development and mechanical properties in QP980 steel
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作者 XIE Shuang ZHONG Yong WANG Li 《Baosteel Technical Research》 CAS 2023年第1期22-31,共10页
Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechan... Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechanical properties of a quenching and partitioning(QP) steel sample after two distinct QP processes were analyzed.The results reveal that martensite transformation after quenching resulted in a lathed morphology with higher yield strength and hole expansion ratio.In contrast, bainite transformation after quenching resulted in the formation of a blocky microstructure composed of bainitic ferrite retained austenite and nanoscale precipitates during the subsequent phase transformation at a higher temperature.This kind of final microstructure is beneficial to the elongation of QP steel but detrimental to the hole expansion ratio. 展开更多
关键词 QP steel BAINITE hole expansion quenching temperature
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Residual stress with asymmetric spray quenching for thick aluminum alloy plates
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作者 Ning Fan Zhihui Li +3 位作者 Yanan Li Xiwu Li Yongan Zhang Baiqing Xiong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第11期2200-2211,共12页
Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates.However,the asymmetric or uneven spray water flow rate is inevitable under indust... Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates.However,the asymmetric or uneven spray water flow rate is inevitable under industrial production conditions,which leads to an asymmetric residual stress distribution.The spray quenching treatment was conducted on self-designed spray equipment,and the residual stress along the thickness direction was measured by a layer removal method based on deflections.Under the asymmetric spray quenching condition,the subsurface stress of the high-flow rate surface was lower than that of the low-flow rate surface,and the difference between the two subsurface stresses increased with the increase in the difference in water flow rates.The subsurface stress underneath the surface with a water flow rate of 0.60 m^(3)/h was 15.38 MPa less than that of 0.15 m^(3)/h.The simulated residual stress by finite element(FE)method of the high heat transfer coefficient(HTC)surface was less than that of the low HTC surface,which is consistent with the experimental results.The FE model can be used to analyze the strain and stress evolution and predict the quenched stress magnitude and distribution. 展开更多
关键词 aluminum alloy spray quenching residual stress layer removal method finite element method
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Effect of quenching and tempering processes on properties and microstructure of G115 steel
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作者 WANG Tingting XU Songqian 《Baosteel Technical Research》 CAS 2023年第4期17-21,共5页
The novel martensitic heat-resistant steel G115 was designed for thick-section boiler components of ultra-supercritical(USC) power plants at 630-650 ℃.The impact of the quenching and tempering processes on the proper... The novel martensitic heat-resistant steel G115 was designed for thick-section boiler components of ultra-supercritical(USC) power plants at 630-650 ℃.The impact of the quenching and tempering processes on the properties and microstructure of G115 steel was explored.The samples that were quenched and tempered twice had a higher tensile strength at room temperature and 650 ℃,and the impact energy was significantly improved.The strength and impact energy increased in proportion to the increase in the first quenching temperature.The microstructure differences between the single and double quenched and tempered samples were examined using metallographic microscopy and scanning electron microscopy.The grain size of the double quenched and tempered samples was finer than that of the single quenched and tempered samples, and the tempered martensite lath is more visible, as are the carbides and other precipitates, which are finer and more uniformly distributed.As the first quenching temperature increased, the grains became coarser but more uniform. 展开更多
关键词 G115 quenching and tempering tensile properties MICROSTRUCTURE
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Development and Application of Multi-phase Nitrides Bonded Silicon Carbide Lintel Blocks for Dry Quenching Furnaces
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作者 CAO Huiyan FENG Yanbin +4 位作者 ZHANG Xinhua HUANG Zhigang LI Jie WANG Xinhui WU Jiguang 《China's Refractories》 CAS 2023年第2期7-11,共5页
Multi-phase nitrides bonded silicon carbide lintel blocks were prepared using industrial SiC(SiC≥98 mass%,3-0.5,≤0.5 and≤0.044 mm),Si powder(Si≥98 mass%,≤0.044 mm),and SiO2 micropowder(SiO2≥96 mass%,d50=0.15 pm)... Multi-phase nitrides bonded silicon carbide lintel blocks were prepared using industrial SiC(SiC≥98 mass%,3-0.5,≤0.5 and≤0.044 mm),Si powder(Si≥98 mass%,≤0.044 mm),and SiO2 micropowder(SiO2≥96 mass%,d50=0.15 pm)as raw materials,and calcium lignosulfonate as the additive,batching,mixing,and molding on a vibration pressure molding machine,drying and then firing at 1420℃for 10 h in high-purity N2.The apparent porosity,the bulk density,the cold modulus of rupture,the hot modulus of rupture,and the linear expansion coefficient of the samples were tested.The phase composition and the microstructure of the samples at different nitriding depths(50,100,and 150 mm)were analyzed by XRD and SEM.The field application effects of the blocks were studied.The results show that:(1)the multi-phase nitrides bonded silicon carbide refractories can dynamically adjust their own phase composition and minimize structural and thermal stresses,improving the service life of key parts of dry quenching furnaces;(2)calcium lignosulfonate can improve the nitriding micro-environment of multi-phase nitrides bonded silicon carbide lintel blocks,successfully increasing the effective nitriding thickness of the blocks to 300 mm;(3)Sinosteel LI RR provides a unique concept in the design of materials and block types as well as the stable and scientific overall structure,promoting the industrialization process of dry quenching furnaces with long service life in China. 展开更多
关键词 inclined channel area dry quenching furnaces silicon carbide multi-phase nitrides lintel blocks
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Dynamical nonlinear excitations induced by interaction quench in a two-dimensional box-trapped Bose-Einstein condensate
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作者 牛真霞 高超 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期209-215,共7页
Manipulating nonlinear excitations,including solitons and vortices,is an essential topic in quantum many-body physics.A new progress in this direction is a protocol proposed in[Phys.Rev.Res.2043256(2020)]to produce da... Manipulating nonlinear excitations,including solitons and vortices,is an essential topic in quantum many-body physics.A new progress in this direction is a protocol proposed in[Phys.Rev.Res.2043256(2020)]to produce dark solitons in a one-dimensional atomic Bose–Einstein condensate(BEC)by quenching inter-atomic interaction.Motivated by this work,we generalize the protocol to a two-dimensional BEC and investigate the generic scenario of its post-quench dynamics.For an isotropic disk trap with a hard-wall boundary,we find that successive inward-moving ring dark solitons(RDSs)can be induced from the edge,and the number of RDSs can be controlled by tuning the ratio of the after-and before-quench interaction strength across different critical values.The role of the quench played on the profiles of the density,phase,and sound velocity is also investigated.Due to the snake instability,the RDSs then become vortex–antivortex pairs with peculiar dynamics managed by the initial density and the after-quench interaction.By tuning the geometry of the box traps,demonstrated as polygonal ones,more subtle dynamics of solitons and vortices are enabled.Our proposed protocol and the discovered rich dynamical effects on nonlinear excitations can be realized in near future cold-atom experiments. 展开更多
关键词 Bose-Einstein condensate quench interaction SOLITON vortex
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Phase diagram and quench dynamics of a periodically drivenHaldane model
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作者 Minxuan Ren Han Yang Mingyuan Sun 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期317-325,共9页
We investigate a periodically driven Haldane model subjected to a two-stage driving scheme in the form of a step function.By using the Floquet theory,we obtain the topological phase diagram of the system.We also find ... We investigate a periodically driven Haldane model subjected to a two-stage driving scheme in the form of a step function.By using the Floquet theory,we obtain the topological phase diagram of the system.We also find that anomalous Floquet topological phases exist in the system.Focusing on examining the quench dynamics among topological phases,we analyze the site distribution of the 0-mode and p-mode edge states in long-period evolution after a quench.The results demonstrate that,under certain conditions,the site distribution of the 0-mode can be confined at the edge even in long-period evolution.Additionally,both the 0-mode and p-mode can recover and become confined at the edge in long-period evolution when the post-quench parameters(T,M_(2) /M_(1))in the phase diagram cross away from the phase boundary (M_(2)/ M_(1))=(6√3t2)/ M_(1)−1.Furthermore,we conclude that whether the edge state is confined at the edge in the long-period evolution after a quench depends on the similarity of the edge states before and after the quench.Our findings reveal some new characteristics of quench dynamics in a periodically driven system. 展开更多
关键词 Floquet system Haldane model quench dynamics topological phase diagram
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Visualization of Vapor Film Collapse Behavior with Complexity on Quenching Process by Cellular Automaton
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作者 Tsuyoshi Sugimoto 《Journal of Mechanics Engineering and Automation》 2023年第1期7-15,共9页
The vapor film collapse that occurs in the quenching process is complicated and affects the heat treatment quality and its distortion.In order to incorporate it into the MBD(Model Based Development)technology required... The vapor film collapse that occurs in the quenching process is complicated and affects the heat treatment quality and its distortion.In order to incorporate it into the MBD(Model Based Development)technology required these days,it is necessary to predict the quality of heat treatment by CAE(Computer Added Engineering),shorten the product development period.The calculation of the vapor film collapses in a simple and practical time in order to improve the product performance.However,in the past,in order to formulate the vapor film collapse on a simulation,it was necessary to perform a very large amount of computational calculation CFD(computational fluid dynamics),which was a problem in terms of computer resources and the model of vapor film collapse.In addition,this phenomenon has a complexity behavior of the phenomenon in iterative processing,which also complicates the calculation.In this study,the vapor film collapse phenomenon is easily visualized using self-organized cellular automaton simulation which includes the phenomena of“vapor film thickness and its fluctuation”,“flow disturbance”,“surface step of workpiece”,and“decrease of cooling due to r shape of surface”.The average cooling state and repeated fluctuations of the cooling state were reproduced by this method. 展开更多
关键词 quenching cellular automaton vapor film collapse complexity.
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Critical current degradation in an epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)coated conductor caused by damage during a quench
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作者 Donghui LIU Huadong YONG Youhe ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第9期1557-1572,共16页
High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of th... High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications. 展开更多
关键词 epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductor(CC) quench DAMAGE critical current degradation shear stress
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Simulation of temperature and stress in 6061 aluminum alloy during online quenching process 被引量:6
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作者 王孟君 杨刚 +1 位作者 黄长清 陈彬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2168-2173,共6页
The cooling curves of 6061 aluminum alloy were acquired through water quenching experiment. The heat transfer coefficient was accurately calculated based on the cooling curves and the law of cooling. The online quench... The cooling curves of 6061 aluminum alloy were acquired through water quenching experiment. The heat transfer coefficient was accurately calculated based on the cooling curves and the law of cooling. The online quenching process of complex cross-section profile was dynamically simulated by the ABAQUS software. The results suggest that the heat transfer coefficient changes during online quenching process. Different parts of the profile have different cooling velocity, and it was verified by water quenching experiment. The maximum residual stress of the profile was predicted using FEM simulation based on ABAQUS software The relations between the temperature and stress were presented by analyzing the data of key points. 展开更多
关键词 6061 aluminum alloy quenching complex cross-section profile residual stress ABAQUS
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Optimum design of flow distribution in quenching tank for heat treatment of A357 aluminum alloy large complicated thin-wall workpieces by CFD simulation and ANN approach 被引量:5
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作者 杨夏炜 朱景川 +3 位作者 何东 来忠红 农智升 刘勇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1442-1451,共10页
Based on the computational fluid dynamics (CFD) method, a quenching tank with two agitator systems and two flow-equilibrating devices was selected to simulate flow distribution using Fluent software. A numerical exa... Based on the computational fluid dynamics (CFD) method, a quenching tank with two agitator systems and two flow-equilibrating devices was selected to simulate flow distribution using Fluent software. A numerical example was used to testify the validity of the quenching tank model. In order to take tank parameters (agitation speed, position of directional flow baffle and coordinate position in quench zone) into account, an approach that combines the artificial neural network (ANN) with CFD method was developed to study the flow distribution in the quenching tank. The flow rate of the quenching medium shows a very good agreement between the ANN predicted results and the Fluent simulated data. Methods for the optimal design of the quenching tank can be used as technical support for industrial production. 展开更多
关键词 A357 aluminum alloy computational fluid dynamics quenching tank flow distribution artificial neural network
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遏止(Quenching)及其在分析RTD逻辑电路中的应用 被引量:1
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作者 郭维廉 牛萍娟 +2 位作者 李晓云 刘宏伟 李鸿强 《固体电子学研究与进展》 CAS CSCD 北大核心 2005年第3期403-409,共7页
在深入分析共振隧穿二极管(RTD)开关前后内阻变化和RTD串联组合中不同RTD电压分布随总偏压变化的基础上,深化了“遏止(Q uench ing)”的概念。并进一步以此概念说明了RTD/HEM T电路中,单-双稳转换逻辑单元(M OB ILE)、多值逻辑(M VL)文... 在深入分析共振隧穿二极管(RTD)开关前后内阻变化和RTD串联组合中不同RTD电压分布随总偏压变化的基础上,深化了“遏止(Q uench ing)”的概念。并进一步以此概念说明了RTD/HEM T电路中,单-双稳转换逻辑单元(M OB ILE)、多值逻辑(M VL)文字(L itera l)逻辑门、三态反相器(T ernary inverter)等逻辑单元的工作原理。通过此种分析,证实了“遏止”概念是解释和分析复杂RTD电路原理的强有力工具。以上论证也适用于由其它负阻器件构成的逻辑电路。 展开更多
关键词 遏止 共振隧穿二极管 共振隧穿二极管逻辑电路 多值逻辑 单-双稳转换逻辑单元
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STUDY ON THE MECHANISM OF FLUORESCENCE QUENCHING OF NITROCOMPOUNDS FOR OXAZOLES *
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作者 齐欣 杨学茹 +3 位作者 刘东志 游得华 王淑丽 张文勤 《Transactions of Tianjin University》 EI CAS 1998年第1期54-57,共4页
The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluores... The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluorescence of oxazoles was quenched mainly by the absorption competition and radiationless energy transfer of nitrocompounds. The fluorescence quenching rate constants of nitrobenzene and nitromethane are 3.0×10 10 L·mol -1 ·s -1 and 1.5×10 8 L·mol -1 ·s -1 respectively for POEOP. This remarkable difference was explicated. 展开更多
关键词 fluorescence quenching nitrocompound OXAZOLES energy transfer absorption competition
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Ultrafast Fluorescence Quenching in LnFe(CN)_6·4H_2O
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作者 孟建新 戴德昌 +1 位作者 李润华 周建英 《中山大学学报论丛》 1997年第5期42-45,共4页
对LnFe(CN)6·4H2O(Ln=Eu,Tb)体系的吸收光谱和荧光光谱的研究表明,两配合物的中Eu3+和Tb3+离子的荧光发生强烈猝灭,即使是用高功率激光直接激发Eu3+的7F0→5D0跃迁也是如此,表明该体... 对LnFe(CN)6·4H2O(Ln=Eu,Tb)体系的吸收光谱和荧光光谱的研究表明,两配合物的中Eu3+和Tb3+离子的荧光发生强烈猝灭,即使是用高功率激光直接激发Eu3+的7F0→5D0跃迁也是如此,表明该体系中稀土离子的荧光寿命非常短,有可能满足室温超快相干控制的要求. 展开更多
关键词 LnFe(CN)6·4H2O 荧光猝灭 相干控制
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退化反应扩散方程熄灭(quenching)点的唯一性
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作者 许广山 马忠泰 《山东师范大学学报(自然科学版)》 CAS 2004年第4期9-12,共4页
研究退化反应扩散方程xqut-utt-uxx=f(u) ,(x ,t)∈ ( 0 ,a)× ( 0 ,T)适合初值条件u(x,0 ) =0 ,x∈ [0 ,a]和边界条件ux+αiu =0 ,(x,t)∈ {0 ,a}× ( 0 ,T) .利用文中建立的比较原理 ,得到了退化反应扩散方程的单点熄灭和熄... 研究退化反应扩散方程xqut-utt-uxx=f(u) ,(x ,t)∈ ( 0 ,a)× ( 0 ,T)适合初值条件u(x,0 ) =0 ,x∈ [0 ,a]和边界条件ux+αiu =0 ,(x,t)∈ {0 ,a}× ( 0 ,T) .利用文中建立的比较原理 ,得到了退化反应扩散方程的单点熄灭和熄灭点的唯一性 . 展开更多
关键词 退化反应扩散方程 单点熄灭及唯一性 初边值和边值问题 比较原理
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Numerical Simulation on Carburizing and Quenching of Gear Ring 被引量:13
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作者 SONG Guang-sheng LIU Xiang-hua +1 位作者 WANG Guo-dong XU Xiang-qiu 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第6期47-52,共6页
The carburizing process of the gear ring was simulated by taking into account the practical carburizing and quenching techniques of the gear ring and by solving the diffusion equation. The carbon content distribution ... The carburizing process of the gear ring was simulated by taking into account the practical carburizing and quenching techniques of the gear ring and by solving the diffusion equation. The carbon content distribution in the carburized layer was obtained. Based on the results, the quenching process of the gear ring was then simulated using the metallic thermodynamics and FEM: it was found that the carburization remarkably affects the quenching process. Microstructures and stress distributions of the gear ring in the quenching process were simulated, and the results are confirmed by experiments. 展开更多
关键词 CARBURIZATION FEM quenching martensite transformation residual stress
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The Mechanisms and Applications of Quorum Sensing(QS) and Quorum Quenching(QQ) 被引量:8
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作者 ZHANG Jingjing FENG Tao +2 位作者 WANG Jiayi WANG Yan ZHANG Xiao-Hua 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1427-1442,共16页
Quorum sensing(QS)is a regulatory system that regulates the behavior of microbial populations by sensing the concentration of signal molecules that are spontaneously produced and released by bacteria.The strategy of b... Quorum sensing(QS)is a regulatory system that regulates the behavior of microbial populations by sensing the concentration of signal molecules that are spontaneously produced and released by bacteria.The strategy of blocking the QS system and inhibiting the production of virulence factors is termed as quorum quenching(QQ).This strategy attenuates virulence without killing the pathogens,thereby weakening the selective pressure on pathogens and postponing the evolution of QQ-mediated drug resistance.In recent years,there have been significant theoretical and practical developments in the field of QS and QQ.In particular,with the development and utilization of marine resources,more and more marine microbial species have been found to be regulated by these two mechanisms,further promoting the research progress of QS and QQ.In this review,we described the diversity of QS signals and QS-related regulatory systems,and then introduced mechanisms related to QS interference,with particular emphasis on the description of natural QQ enzymes and chemicals acting as QS inhibitors.Finally,the exploitation of quorum sensing quenchers and the practical application of QQ were introduced,while some QQ strategies were proposed as promising tools in different fields such as medicine,aquaculture,agriculture and biological pollution prevention areas. 展开更多
关键词 QUORUM sensing QUORUM quenching MARINE MICROORGANISMS antibiotic resistance
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