Rare-earth elements(REEs)received special attention and widespread application because of their extremely active chemical property.Many researches demonstrated that doping of REEs(Y,La and Ce)in superalloys can signif...Rare-earth elements(REEs)received special attention and widespread application because of their extremely active chemical property.Many researches demonstrated that doping of REEs(Y,La and Ce)in superalloys can significantly improve the high temperature oxidation resistance,corrosion resistance and mechanical properties,which are recognized as a promising route to broaden the manufacturing process window and enhance the overall performance of next-generation superalloys.The first part of this review described the special behavior of REEs during the metallurgical solidification process,including the REEs loss in the melt and the macro-segregation phenomenon.The second part summarized a broad spectrum of works reporting the dual role of REEs addition on the mechanical properties of superalloys.The third part overviewed the effect of REEs on the anti-oxidation resistance of the fourth and fifth nickel-based superalloys.Finally,the prospect of development of REEs-containing superalloys was discussed.展开更多
Using the skyrme energy density formalism, a pocket formula is introduced for barrier heights and positions of 95 fusion reactions(48≤ZPZT≤1520) with respect to the charge and mass numbers of the interacting nuclei....Using the skyrme energy density formalism, a pocket formula is introduced for barrier heights and positions of 95 fusion reactions(48≤ZPZT≤1520) with respect to the charge and mass numbers of the interacting nuclei. It is shown that the parameterized values of RBand VBare able to reproduce the corresponding experimental data with good accuracy. Moreover, the absolute errors of our formulas are less than those obtained using the analytical parametrization forms of the fusion barrier based on the proximity versions. The ability of the parameterized forms of the barrier heights and its positions to reproduce the experimental data of the fusion cross section have been analyzed using the Wong model.展开更多
The glaucomas are a group of optic neuropathies comprising the leading cause of irreversible blindness worldwide. Elevated intraocular pressure due to a reduction in normal aqueous outflow is a major causal risk facto...The glaucomas are a group of optic neuropathies comprising the leading cause of irreversible blindness worldwide. Elevated intraocular pressure due to a reduction in normal aqueous outflow is a major causal risk factor. We recently reported that En-dothelial Leukocyte Adhesion Molecule-1 (ELAM-1), the earliest marker for the atherosclerotic plaque in the vasculature.展开更多
The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were...The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.展开更多
Purpose Improved resistive plate chambers(iRPCs)will be installed in the challenging forward region of the compact muon solenoid(CMS)during its Phase-2 upgrade.The design target of iRPC time resolution is 1.5 ns.It wi...Purpose Improved resistive plate chambers(iRPCs)will be installed in the challenging forward region of the compact muon solenoid(CMS)during its Phase-2 upgrade.The design target of iRPC time resolution is 1.5 ns.It will help the Level-1 trigger system distinguish the muons from high backgrounds and improve the trigger efficiency.Studying the time resolution after integrating the new backend electronics boards(BEB)is essential for ensuring timely performance.In this system,a time reference(Tref)signal is distributed by the BEB to several frontend electronics boards(FEB)to reset the time-to-digital converters(TDC).In the CMS experiment,the arrangement of the iRPC chambers and on-chamber FEBs is at different positions,resulting in varying Tref arrival times on the FEB side.This paper describes the measures taken to ensure the time resolution of the single path and adjust the time base for multi-paths.Method Unique designs were implemented in the chamber,FEB,and BEB to ensure a satisfactory time resolution.Tref adjustments for different paths were performed in bunch crossing steps(24.950 ns)in the BEB using shift registers.And the sub-bunch crossing adjustment steps were performed in the FEB using the TDC correction module.Finally,the arrival time differences of Tref on different FEBs were less than 1.25 ns after adjustment.Results The time resolution of the FEB–BEB system was observed to be 32 ps.The time resolution of the chamber FEB–BEB system was first measured and is 554 ps at an iRPC working point of 7200 V.In addition,the Tref arrival time differences of different paths were adjusted from−99.923(−90.113)ns to 0.073(−0.141)ns.Conclusion The test results revealed that the system time resolution and Tref adjustment performed by the BEB met the Phase-2 upgrade goals.展开更多
Purpose The superfast kickers are required for the HEPS storage ring on-axis injection system due to its very small dynamic aperture.A 750-mm-long stripline pair type of kicker prototype was researched and developed t...Purpose The superfast kickers are required for the HEPS storage ring on-axis injection system due to its very small dynamic aperture.A 750-mm-long stripline pair type of kicker prototype was researched and developed to demonstrate achieved performance of bandwidth,impedance,kicker strength,field uniformity and beam power loss.Methods The cross sections of the kicker main body and the end of taper part are optimized for a good impedance matching and field uniformity.3D simulation further optimizes the taper part to minimize the beam power loss and maintain a lower reflection.The high-voltage feedthrough is also designed and optimized by 3D CST.RF and high-voltage measurements are taken to verify the design of kicker assembly.Results The testing transmission odd-mode impedance is 50±0.5Ω,the even-mode impedance is 60±0.5Ω,and return loss is less than−13 dB.The peak voltage and the rise time of pulse width inserting kicker assembly just decrease 3%of 20 kV and slow down 80 ps,respectively.Conclusions RF testing results agree well with the simulation ones,which meet the design specification.The kicker assembly works well at±20 kV pulse.展开更多
Purpose CMOS pixel sensor has become extremely attractive for future high-performance tracking devices.It has been proposed for the vertex detector at the Circular Electron Positron Collider,which will allow precision...Purpose CMOS pixel sensor has become extremely attractive for future high-performance tracking devices.It has been proposed for the vertex detector at the Circular Electron Positron Collider,which will allow precision measurements of the properties of the Higgs boson.To meet the stringent requirements for low power consumption,it is necessary to optimize the pixel sensor diode geometry to reach a high charge-over-capacitance ratio that allows reduction in analog power consumption.Methods Collection electrode size and footprint are two critical elements in sensor diode geometry and have deciding impacts on the charge collection performance.A prototype CMOS pixel sensor,named JadePix-1,has been developed with pixel sectors implemented with different electrode sizes and footprints,and its charge collection performance has been characterized with radioactive sources.Results Charge-to-voltage conversion gains for pixel sectors under test have been calibrated with low-energy X-rays.Characterization results have been obtained for equivalent noise charge(below 10e−),charge collection efficiency(around 40%),charge-over-capacitance ratio(above 0.015 V)and signal-to-noise ratio(higher than 55).Conclusion Small collection electrode size and large footprint are preferred to achieve high charge-over-capacitance ratio that promises low analog power consumption.Ongoing studies on sensor performance before and after irradiation,combined with this work,will conclude the diode geometry optimization.展开更多
Purpose The Large Hadron Collider(LHC)at European Organization for Nuclear Research is planned to be upgraded to the high luminosity LHC.Increasing the luminosity makes muon triggering reliable and offline reconstructi...Purpose The Large Hadron Collider(LHC)at European Organization for Nuclear Research is planned to be upgraded to the high luminosity LHC.Increasing the luminosity makes muon triggering reliable and offline reconstruction very challenging.To enhance the redundancy of the Compact Muon Solenoid(CMS)Muon system and resolve the ambiguity of track reconstruction in the forward region,an improved Resistive Plate Chamber(iRPC)with excellent time resolution will be installed in the Phase-2 CMS upgrade.The iRPC will be equipped with Front-End Electronics(FEE),which can perform high-precision time measurements of signals from both ends of the strip.New Back-End Electronics(BEE)need to be researched and developed to provide sophisticated functionalities such as interacting with FEE with shared links for fast,slow control(SC)and data,in addition to trigger primitives(TPs)generation and data acquisition(DAQ).Method The BEE prototype uses a homemade hardware board compatible with the MTCA standard,the back-end board(BEB).BEE interacts with FEE via a bidirectional 4.8 Gbps optical paired-link that integrates clock,data,and control information.The clock and fast/slow control commands are distributed from BEB to the FEE via the downlink.The uplink is used for BEB to receive the time information of the iRPC’sfired strips and the responses to the fast/slow control commands.To have a pipelined detector data for clusterfinding operation,recover(DeMux)the time relationship of which is changed due to the transmission protocol for the continuous incoming MUXed data from FEE.Then at each bunch crossing(BX),clusteringfired strips that satisfy time and spatial constraints to generate TPs.Both incoming raw MUXed detector data and TPs in a time window and latency based on the trigger signal are read out to the DAQ system.Gigabit Ethernet(GbE)of SiTCP and commercial 10-GbE are used as link standards for SC and DAQ,respectively,for the BEB to interact with the server.Results The joint test results of the BEB with iRPC and Front-End Board(FEB)show a Bit Error Rate of the transmission links less than 1×10-16,a time resolution of the FEB Time-to-Digital Converter of 16 ps,and the resolution of the time difference between both ends of 160 ps which corresponding a spatial resolution of the iRPC of approximately 1.5 cm.Conclusion Test results showed the correctness and stable running of the BEB prototype,of which the functionalities fulfill the iRPC requirements.展开更多
In this paper,we propose a strong stability-preserving predictor-corrector(SSPC)method based on an implicit Runge-Kutta method to solve the acoustic-and elastic-wave equations.We first transform the wave equations int...In this paper,we propose a strong stability-preserving predictor-corrector(SSPC)method based on an implicit Runge-Kutta method to solve the acoustic-and elastic-wave equations.We first transform the wave equations into a system of ordinary differential equations(ODEs)and apply the local extrapolation method to discretize the spatial high-order derivatives,resulting in a system of semi-discrete ODEs.Then we use the SSPC method based on an implicit Runge-Kutta method to solve the semi-discrete ODEs and introduce a weighting parameter into the SSPC method.On top of such a structure,we develop a robust numerical algorithm to effectively suppress the numerical dispersion,which is usually caused by the discretization of wave equations when coarse grids are used or geological models have large velocity contrasts between adjacent layers.Meanwhile,we investigate the performance of the SSPC method including numerical errors and convergence rate,numerical dispersion,and stability criteria with different choices of the weighting parameter to solve 1-D and 2-D acoustic-and elastic-wave equations.When the SSPC is applied to seismic simulations,the computational efficiency is also investigated by comparing the SSPC,the fourth-order Lax-Wendroff correction(LWC)method,and the staggered-grid(SG)finite differencemethod.Comparisons of synthetic waveforms computed by the SSPC and analytic solutions for acoustic and elastic models are given to illustrate the accuracy and the validity of the SSPCmethod.Furthermore,several numerical experiments are conducted for the geological models including a 2-D homogeneous transversely isotropic(TI)medium,a two-layer elastic model,and the 2-D SEG/EAGE salt model.The results show that the SSPC can be used as a practical tool for large-scale seismic simulation because of its effectiveness in suppressing numerical dispersion even in the situations such as coarse grids,strong interfaces,or high frequencies.展开更多
Purpose To complement and ensure redundancy in the endcap muon system of the Compact Muon Solenoid(CMS)detector and to extend the Resistive Plate Chamber(RPC)system coverage,improved RPCs(iRPCs)with either orthogonal ...Purpose To complement and ensure redundancy in the endcap muon system of the Compact Muon Solenoid(CMS)detector and to extend the Resistive Plate Chamber(RPC)system coverage,improved RPCs(iRPCs)with either orthogonal layer strips with one-end electronics or single layer strips with two-end electronics providing more precise time measurement will be installed in the very forward pseudorapidity region of|η|<2.4.The iRPC readout system needs to support twodimensional(2D)or two-end readout.In addition,it must combine detector data with Timing,Trigger and fast Control(TTC)and Slow Control(SC)into one data stream over a bi-directional optical link with a line rate of 4.8 Gb/s between the Front-End Electronics(FEE)and the Back-End Electronics(BEE).To fulfill these requirements,a prototype BEE for the iRPC 2D chamber has been researched and designed.Methods A Micro-Telecommunication and Computing Architecture(μTCA)-based processing card was designed in this study to establish a prototype system together with aμTCA crate.The Giga-Bit Transceiver(GBT)protocol is integrated to provide bi-directional communication between the FEE and BEE.A server is connected with the BEE by a Gigabit Ethernet(GbE)link for SC and a 10-GbE link for Data AcQuisition(DAQ).Results The Bit Error Rate(BER)test of the back-end board and a joint test with the iRPC 2D prototype chamber were performed.ABERof less than 1.331×10−16 was obtained.The timemeasurement with a resolution of 3.05 nswas successfully realized,and detector efficiencies of 97.7%for longitudinal strips and 96.0%for orthogonal strips were measured.Test results demonstrate the correctness and reliability of the prototype BEE.Conclusion The BEE prototype satisfies the requirements for the iRPC 2D chamber,and it worked stably and reliably during a long-term joint test run.展开更多
基金supported by the National Science and Technology Major Project(Nos.J2019-VI-0023-0139 and J2019-VII-0004-0144)the National Key R&D Program of China(No.2020YFA0714904).
文摘Rare-earth elements(REEs)received special attention and widespread application because of their extremely active chemical property.Many researches demonstrated that doping of REEs(Y,La and Ce)in superalloys can significantly improve the high temperature oxidation resistance,corrosion resistance and mechanical properties,which are recognized as a promising route to broaden the manufacturing process window and enhance the overall performance of next-generation superalloys.The first part of this review described the special behavior of REEs during the metallurgical solidification process,including the REEs loss in the melt and the macro-segregation phenomenon.The second part summarized a broad spectrum of works reporting the dual role of REEs addition on the mechanical properties of superalloys.The third part overviewed the effect of REEs on the anti-oxidation resistance of the fourth and fifth nickel-based superalloys.Finally,the prospect of development of REEs-containing superalloys was discussed.
文摘Using the skyrme energy density formalism, a pocket formula is introduced for barrier heights and positions of 95 fusion reactions(48≤ZPZT≤1520) with respect to the charge and mass numbers of the interacting nuclei. It is shown that the parameterized values of RBand VBare able to reproduce the corresponding experimental data with good accuracy. Moreover, the absolute errors of our formulas are less than those obtained using the analytical parametrization forms of the fusion barrier based on the proximity versions. The ability of the parameterized forms of the barrier heights and its positions to reproduce the experimental data of the fusion cross section have been analyzed using the Wong model.
文摘The glaucomas are a group of optic neuropathies comprising the leading cause of irreversible blindness worldwide. Elevated intraocular pressure due to a reduction in normal aqueous outflow is a major causal risk factor. We recently reported that En-dothelial Leukocyte Adhesion Molecule-1 (ELAM-1), the earliest marker for the atherosclerotic plaque in the vasculature.
基金Supported by the National Nature Science Foundation of China(U2167204,11975040,1832130)The Brazilian authors thank the partial financial support from CNPq,FAPERJ,and INCT-FNA(Instituto Nacional de Ciência e Tecnologia,Física Nuclear e Aplicações),research Project No.(464898/2014-5)+4 种基金supported by(M.S.)the U.S.Department of Energy,Office of Science,and Office of Nuclear Physics(DE-AC02-06CH11357)supported By the Key Research and Development Program of Guangdong Province,China(2020B040420005)the Basic and Applied Basic Research Foundation of Guangdong Province,China(2021B1515120027)LingChuang Research Project of China National Nuclear Corporation(20221024000072F6-0002-7)the Nuclear Energy Development and Research Project(HNKF202224(28)),and the'111'Center(B20065).
文摘The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.
基金supported in part by the National Key R&D Program of China(No.2022YFA1602101)the National Natural Science Foundation of China(No.12035018)+26 种基金We would also like to acknowledge the enduring support for the CMS Phase-2 upgrade and the supporting computing infrastructure provided by the following funding agencies:FWO(Belgium)CNPq(Brazil),CAPES(Brazil)FAPERJ(Brazil)MES(Bulgaria)BNSF(Bulgaria)CERNCAS(China)MoST(China)MINCIENCIAS(Colombia)CEA(France)CNRS/IN2P3(France)SRNSFG(Georgia)[YS-21-1798]DAE(India)DST(India)IPM(Iran)INFN(Italy)MSIP(Republic of Korea)NRF(Republic of Korea)BUAP(Mexico)CINVESTAV(Mexico)CONACYT(Mexico)LNS(Mexico)SEP(Mexico)UASLP-FAI(Mexico)PAEC(Pakistan)DOE(USA)NSF(USA).
文摘Purpose Improved resistive plate chambers(iRPCs)will be installed in the challenging forward region of the compact muon solenoid(CMS)during its Phase-2 upgrade.The design target of iRPC time resolution is 1.5 ns.It will help the Level-1 trigger system distinguish the muons from high backgrounds and improve the trigger efficiency.Studying the time resolution after integrating the new backend electronics boards(BEB)is essential for ensuring timely performance.In this system,a time reference(Tref)signal is distributed by the BEB to several frontend electronics boards(FEB)to reset the time-to-digital converters(TDC).In the CMS experiment,the arrangement of the iRPC chambers and on-chamber FEBs is at different positions,resulting in varying Tref arrival times on the FEB side.This paper describes the measures taken to ensure the time resolution of the single path and adjust the time base for multi-paths.Method Unique designs were implemented in the chamber,FEB,and BEB to ensure a satisfactory time resolution.Tref adjustments for different paths were performed in bunch crossing steps(24.950 ns)in the BEB using shift registers.And the sub-bunch crossing adjustment steps were performed in the FEB using the TDC correction module.Finally,the arrival time differences of Tref on different FEBs were less than 1.25 ns after adjustment.Results The time resolution of the FEB–BEB system was observed to be 32 ps.The time resolution of the chamber FEB–BEB system was first measured and is 554 ps at an iRPC working point of 7200 V.In addition,the Tref arrival time differences of different paths were adjusted from−99.923(−90.113)ns to 0.073(−0.141)ns.Conclusion The test results revealed that the system time resolution and Tref adjustment performed by the BEB met the Phase-2 upgrade goals.
基金Funding was provided by National Natural Science Founda-tion of China(Grant Nos.11475200 and 11675194).
文摘Purpose The superfast kickers are required for the HEPS storage ring on-axis injection system due to its very small dynamic aperture.A 750-mm-long stripline pair type of kicker prototype was researched and developed to demonstrate achieved performance of bandwidth,impedance,kicker strength,field uniformity and beam power loss.Methods The cross sections of the kicker main body and the end of taper part are optimized for a good impedance matching and field uniformity.3D simulation further optimizes the taper part to minimize the beam power loss and maintain a lower reflection.The high-voltage feedthrough is also designed and optimized by 3D CST.RF and high-voltage measurements are taken to verify the design of kicker assembly.Results The testing transmission odd-mode impedance is 50±0.5Ω,the even-mode impedance is 60±0.5Ω,and return loss is less than−13 dB.The peak voltage and the rise time of pulse width inserting kicker assembly just decrease 3%of 20 kV and slow down 80 ps,respectively.Conclusions RF testing results agree well with the simulation ones,which meet the design specification.The kicker assembly works well at±20 kV pulse.
基金the National Natural Science Foundation of China(Nos.11505207,11573028)the State Key Laboratory of Particle Detection and Electronics,the CAS Center for Excellence in Particle Physics(CCEPP)and the IHEP Innovation Fund and the International Partnership Program of Chinese Academy of Sciences.
文摘Purpose CMOS pixel sensor has become extremely attractive for future high-performance tracking devices.It has been proposed for the vertex detector at the Circular Electron Positron Collider,which will allow precision measurements of the properties of the Higgs boson.To meet the stringent requirements for low power consumption,it is necessary to optimize the pixel sensor diode geometry to reach a high charge-over-capacitance ratio that allows reduction in analog power consumption.Methods Collection electrode size and footprint are two critical elements in sensor diode geometry and have deciding impacts on the charge collection performance.A prototype CMOS pixel sensor,named JadePix-1,has been developed with pixel sectors implemented with different electrode sizes and footprints,and its charge collection performance has been characterized with radioactive sources.Results Charge-to-voltage conversion gains for pixel sectors under test have been calibrated with low-energy X-rays.Characterization results have been obtained for equivalent noise charge(below 10e−),charge collection efficiency(around 40%),charge-over-capacitance ratio(above 0.015 V)and signal-to-noise ratio(higher than 55).Conclusion Small collection electrode size and large footprint are preferred to achieve high charge-over-capacitance ratio that promises low analog power consumption.Ongoing studies on sensor performance before and after irradiation,combined with this work,will conclude the diode geometry optimization.
基金supported by the National Natural Science Foundation of China(No.12035018)the IHEP Innovation Fund(Y9545150U2)the National Key Programme for S&T Research and Development(Grant No.:2016YFA0400104).
文摘Purpose The Large Hadron Collider(LHC)at European Organization for Nuclear Research is planned to be upgraded to the high luminosity LHC.Increasing the luminosity makes muon triggering reliable and offline reconstruction very challenging.To enhance the redundancy of the Compact Muon Solenoid(CMS)Muon system and resolve the ambiguity of track reconstruction in the forward region,an improved Resistive Plate Chamber(iRPC)with excellent time resolution will be installed in the Phase-2 CMS upgrade.The iRPC will be equipped with Front-End Electronics(FEE),which can perform high-precision time measurements of signals from both ends of the strip.New Back-End Electronics(BEE)need to be researched and developed to provide sophisticated functionalities such as interacting with FEE with shared links for fast,slow control(SC)and data,in addition to trigger primitives(TPs)generation and data acquisition(DAQ).Method The BEE prototype uses a homemade hardware board compatible with the MTCA standard,the back-end board(BEB).BEE interacts with FEE via a bidirectional 4.8 Gbps optical paired-link that integrates clock,data,and control information.The clock and fast/slow control commands are distributed from BEB to the FEE via the downlink.The uplink is used for BEB to receive the time information of the iRPC’sfired strips and the responses to the fast/slow control commands.To have a pipelined detector data for clusterfinding operation,recover(DeMux)the time relationship of which is changed due to the transmission protocol for the continuous incoming MUXed data from FEE.Then at each bunch crossing(BX),clusteringfired strips that satisfy time and spatial constraints to generate TPs.Both incoming raw MUXed detector data and TPs in a time window and latency based on the trigger signal are read out to the DAQ system.Gigabit Ethernet(GbE)of SiTCP and commercial 10-GbE are used as link standards for SC and DAQ,respectively,for the BEB to interact with the server.Results The joint test results of the BEB with iRPC and Front-End Board(FEB)show a Bit Error Rate of the transmission links less than 1×10-16,a time resolution of the FEB Time-to-Digital Converter of 16 ps,and the resolution of the time difference between both ends of 160 ps which corresponding a spatial resolution of the iRPC of approximately 1.5 cm.Conclusion Test results showed the correctness and stable running of the BEB prototype,of which the functionalities fulfill the iRPC requirements.
文摘In this paper,we propose a strong stability-preserving predictor-corrector(SSPC)method based on an implicit Runge-Kutta method to solve the acoustic-and elastic-wave equations.We first transform the wave equations into a system of ordinary differential equations(ODEs)and apply the local extrapolation method to discretize the spatial high-order derivatives,resulting in a system of semi-discrete ODEs.Then we use the SSPC method based on an implicit Runge-Kutta method to solve the semi-discrete ODEs and introduce a weighting parameter into the SSPC method.On top of such a structure,we develop a robust numerical algorithm to effectively suppress the numerical dispersion,which is usually caused by the discretization of wave equations when coarse grids are used or geological models have large velocity contrasts between adjacent layers.Meanwhile,we investigate the performance of the SSPC method including numerical errors and convergence rate,numerical dispersion,and stability criteria with different choices of the weighting parameter to solve 1-D and 2-D acoustic-and elastic-wave equations.When the SSPC is applied to seismic simulations,the computational efficiency is also investigated by comparing the SSPC,the fourth-order Lax-Wendroff correction(LWC)method,and the staggered-grid(SG)finite differencemethod.Comparisons of synthetic waveforms computed by the SSPC and analytic solutions for acoustic and elastic models are given to illustrate the accuracy and the validity of the SSPCmethod.Furthermore,several numerical experiments are conducted for the geological models including a 2-D homogeneous transversely isotropic(TI)medium,a two-layer elastic model,and the 2-D SEG/EAGE salt model.The results show that the SSPC can be used as a practical tool for large-scale seismic simulation because of its effectiveness in suppressing numerical dispersion even in the situations such as coarse grids,strong interfaces,or high frequencies.
基金the National Key Programme for S&T Research and Development(Grant NO.:2016YFA0400104)the National Natural Science Foundation of China(No.12035018)the IHEP Innovation Fund(Y9545150U2).
文摘Purpose To complement and ensure redundancy in the endcap muon system of the Compact Muon Solenoid(CMS)detector and to extend the Resistive Plate Chamber(RPC)system coverage,improved RPCs(iRPCs)with either orthogonal layer strips with one-end electronics or single layer strips with two-end electronics providing more precise time measurement will be installed in the very forward pseudorapidity region of|η|<2.4.The iRPC readout system needs to support twodimensional(2D)or two-end readout.In addition,it must combine detector data with Timing,Trigger and fast Control(TTC)and Slow Control(SC)into one data stream over a bi-directional optical link with a line rate of 4.8 Gb/s between the Front-End Electronics(FEE)and the Back-End Electronics(BEE).To fulfill these requirements,a prototype BEE for the iRPC 2D chamber has been researched and designed.Methods A Micro-Telecommunication and Computing Architecture(μTCA)-based processing card was designed in this study to establish a prototype system together with aμTCA crate.The Giga-Bit Transceiver(GBT)protocol is integrated to provide bi-directional communication between the FEE and BEE.A server is connected with the BEE by a Gigabit Ethernet(GbE)link for SC and a 10-GbE link for Data AcQuisition(DAQ).Results The Bit Error Rate(BER)test of the back-end board and a joint test with the iRPC 2D prototype chamber were performed.ABERof less than 1.331×10−16 was obtained.The timemeasurement with a resolution of 3.05 nswas successfully realized,and detector efficiencies of 97.7%for longitudinal strips and 96.0%for orthogonal strips were measured.Test results demonstrate the correctness and reliability of the prototype BEE.Conclusion The BEE prototype satisfies the requirements for the iRPC 2D chamber,and it worked stably and reliably during a long-term joint test run.
