期刊文献+
共找到4,388篇文章
< 1 2 220 >
每页显示 20 50 100
Apatite Fission Track Thermochronology of Granite from the Xiazhuang Uranium Ore Field,South China:Implications for Exhumation History and Ore Preservation
1
作者 SUN Yue CHEN Zhengle +4 位作者 PAN Jiayong HUO Hailong LI Haidong SUN Junjie XU Guangchun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期430-440,共11页
Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track... Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track data and thermal history modeling to constrain the exhumation history and evaluate preservation potential of the Xiazhuang Uranium ore field.Nine Triassic outcrop granite samples collected from different locations of Xiazhuang Uranium ore field yield AFT ages ranging from 43 to 24 Ma with similar mean confined fission track lengths ranging from 11.8±2.0 to 12.9±1.9μm and Dpar values between 1.01 and 1.51μm.The robustness time-temperature reconstructions of samples from the hanging wall of Huangpi fault show that the Xiazhuang Uranium ore field experienced a time of monotonous and slow cooling starting from middle Paleocene to middle Miocene(~60-10 Ma),followed by relatively rapid exhumation in the late Miocene(~10-5 Ma)and nearly thermal stability in the Pliocene-Quaternary(~5-0 Ma).The amount of exhumation after U mineralization since the Middle Paleogene was estimated as~4.3±1.8 km according to the integrated thermal history model.Previous studies indicate that the ore-forming ages of U deposits in the Xiazhuang ore field are mainly before Middle Paleocene and the mineralization depths are more than 4.4±1.2 km.Therefore,the exhumation history since middle Paleocene plays important roles in the preservation of the Xiazhuang Uranium ore field. 展开更多
关键词 apatite fission track exhumation history ore preservation Xiazhuang Uranium ore field South China
下载PDF
Impairment of the Regulation of Gonadal Function in Channa punctatus by Metacid-50 and Carbaryl under Laboratory and Field Conditions
2
作者 PROBODH GHOSH SAMIR BHATTACHARYA SHELLEY BHATTACHARYA 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1990年第1期106-112,共7页
Regulation of gonadal function by gonadotropic hormone (GtH) and gonadotropin-releasing hormone (GnRH) in Channa punctatus was significantly affected by nonlethal levels of Metacid-50 and Carbaryl. Under laboratory co... Regulation of gonadal function by gonadotropic hormone (GtH) and gonadotropin-releasing hormone (GnRH) in Channa punctatus was significantly affected by nonlethal levels of Metacid-50 and Carbaryl. Under laboratory conditions, the time-dependent decrease in serum GtH level was higher in Carbaryl-treated fish than in Metacid-50-treated fish. The situation was reversed in the field, with a higher inhibitory effect of Metacid-50 being recorded. On the other hand, pituitary GtH content and GnRH activity were inhibited to a greater extent by Metacid-50 than by Carbaryl under both field and laboratory conditions. The present findings highlight that even low doses of Metacid-50 and Carbaryl are effective enough to cause reproductive damage, as evidenced by homeostatic unbalance of the reproductive regulatory system. 1990 Academic Press. Inc. 展开更多
关键词 Impairment of the regulation of Gonadal Function in Channa punctatus by Metacid-50 and Carbaryl under Laboratory and field Conditions GtH
下载PDF
A prob of the effect of psychological suggestion in Track and Field Sports
3
作者 Chen Lijuan, female, 35 year old, lecturer. Chen Lijuan College of Physical Education, Southwest China Normal University, Chongqing 400715 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 1998年第5期125-128,共4页
Modernsportspsychologicalmovesthatathletesconsumenotonlymuchphysicalstrength,butalsogreatpsychologicalenergy... Modernsportspsychologicalmovesthatathletesconsumenotonlymuchphysicalstrength,butalsogreatpsychologicalenergy,whenthey’reintra... 展开更多
关键词 PSYCHOLOGICAL SUGGESTION EFFECT track and field Sports(T.F.S) training contest
全文增补中
The Effects of Thickness and Location of PCMon the Building’s Passive Temperature-Control–A Numerical Study
4
作者 Zhengrong Shi JieRen +1 位作者 Tao Zhang Yanming Shen 《Energy Engineering》 EI 2024年第3期681-702,共22页
Building energy consumption and building carbon emissions both account for more than 20%of their total national values in China.Building employing phase change material(PCM)for passive temperature control shows a prom... Building energy consumption and building carbon emissions both account for more than 20%of their total national values in China.Building employing phase change material(PCM)for passive temperature control shows a promising prospect in meeting the comfort demand and reducing energy consumption simultaneously.However,there is a lack of more detailed research on the interaction between the location and thickness of PCM and indoor natural convection,as well as indoor temperature distribution.In this study,the numerical model of a passive temperature-controlled building integrating the developed PCM module is established with the help of ANSYS.In which,the actual weather condition of Beijing city is set as the boundary conditions and the indoor natural convection is simulated with the consideration of radiation model.The effects of PCM’s thickness and location on the internal temperature field are analyzed and discussed.The results show that the room could maintain within the human comfort temperature range with the longest ratio of 94.10%and the shortest ratio of 51.04%as integrating PCM.In comparison,the value is only 26.70%without PCM.The room’s maximum temperature fluctuation can also be improved;it could be lowered by 64.4%compared to the normal condition.When the quantity of PCM is sufficient,further increasing the PCM amount results in a temperature fluctuation reduction of less than 0.1°C and does not increase the comfort time.Placing PCM on the wall induces an apparent variation in indoor temperature along the vertical direction.Conversely,placing PCM on the roof can lead to a heat transfer rate difference of up to seven times.The optimal placement of PCM depends on the difference between the environmental and phase change temperatures.If the difference is positive,placing PCM on the roof is more effective;conversely,the opposite holds.According to the results over the entire cycle,PCM application on vertical walls yields better performance.The significant difference in natural convection caused by the same thickness of PCM but different application positions,coupled with the influence of air movement on the melting and solidification of PCM,further impacts indoor temperature fluctuations and comfort.This study can provide guidance for the application location and thickness of PCM,especially for scenarios where temperature regulation is required at a specific time. 展开更多
关键词 Phase change materials passive temperature regulation numerical simulation temperature field
下载PDF
The training process: Planning for strength-power training in track and field. Part 2: Practical and applied aspects 被引量:3
5
作者 Brad H. DeWeese Guy Hornsby +1 位作者 Meg Stone Michael H. Stone 《Journal of Sport and Health Science》 SCIE 2015年第4期318-324,共7页
Planning training programs for strength-power track and field athletes require an understanding of both training principles and training theory. The training principles are overload, variation, and specificity. Each o... Planning training programs for strength-power track and field athletes require an understanding of both training principles and training theory. The training principles are overload, variation, and specificity. Each of these principles must be incorporated into an appropriate system of training. Conceptually, periodization embraces training principles and offers advantages in planning, allowing for logical integration and manipulation of training variables such as exercise selection, intensification, and volume factors. The adaptation and progress of the athlete is to a large extent directly related to the ability of the coach/athlete to create and carry an efficient and efficacious training process. This ability includes: an understanding of how exercises affect physiological and performance adaptation (i.e., maximum force, rate of force development, power, etc.), how to optimize transfer of training effect ensuring that training exercises have maximum potential for carryover to performance, and how to implement programs with variations at appropriate levels (macro, meso, and micro) such that fatigue management is enhanced and performance progress is optimized. 展开更多
关键词 Periodization PROGRAMMING Strength training track and field Training process
下载PDF
The training process: Planning for strength-power training in track and field. Part 1: Theoretical aspects 被引量:3
6
作者 Brad H. DeWeese Guy Hornsby +1 位作者 Meg Stone Michael H. Stone 《Journal of Sport and Health Science》 SCIE 2015年第4期308-317,共10页
The process of strength-power training and the subsequent adaptation is a multi-factorial process. These factors range from the genetics and morphological characteristics of the athlete to how a coach selects, orders,... The process of strength-power training and the subsequent adaptation is a multi-factorial process. These factors range from the genetics and morphological characteristics of the athlete to how a coach selects, orders, and doses exercises and loading patterns. Consequently, adaptation from these training factors may largely relate to the mode of delivery, in other words, programming tactics. There is strong evidence that the manner and phases in which training is presented to the athlete can make a profound difference in performance outcome. This discussion deals primarily with block periodization concepts and associated methods of programming for strength-power training within track and field. 2015 Production and hosting by Elsevier B.V. on behalf of Shanghai University of Sport. 展开更多
关键词 Periodization Strength-power training track and field Training process
下载PDF
Matrix test measurements of ground-borne vibration induced by the heavy-duty trains on embankment and cutting tracks in a loess area 被引量:2
7
作者 Xie Qiang Wu Zhi-Hui +1 位作者 Dong Jie Zhong Shuai 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第3期605-620,共16页
This paper presents a comparative analysis of ground vibration in three directions generated by a heavy-duty railway with various track sections.The vibration characteristics in the plane area were investigated by usi... This paper presents a comparative analysis of ground vibration in three directions generated by a heavy-duty railway with various track sections.The vibration characteristics in the plane area were investigated by using matrix test measurements.Acceleration peak attenuation was faster within 25 m from the embankment,and the high-frequency vibration attenuates faster with increased distance.For the cutting section with multi-stage soil slope,decay rate of acceleration was relatively larger.The acceleration level of the plane region ranged to 82.2-89.1 dB by the single C80 train.Yet the acceleration level caused by the C80 trains running parallel after meeting showed a distinct increment.The increment of the cutting section was much larger compared with the embankment section,with the increment ranging from 1.2-2.5 dB.In terms of the cutting section,Y direction acceleration was dominant closer to the track.Within 10-30 m of the track,the Y direction acceleration(perpendicular to the rail)decreased rapidly and became comparable to the X direction(parallel to the rail)and Z direction.Additionally,the cutting case generated a higher level of vibration in all three directions compared to the embankment,but as the distance from track increased,the deviation between acceleration gradually decreased. 展开更多
关键词 heavy-duty railway different track sections field measurement vibration response characteristics cutting slope
下载PDF
Polyurethane grouting materials with different compositions for the treatment of mud pumping in ballastless track subgrade beds:properties and application effect 被引量:2
8
作者 Zhichao Huang Qian Su +3 位作者 Junjie Huang Minqi Dong Dong Li Ting Liu 《Railway Engineering Science》 2022年第2期204-220,共17页
Mud pumping in subgrade beds under ballastless tracks will deteriorate the dynamic performance of infrastructure under railway lines,reduce the smoothness of the railway lines,and seriously affect the comfort and safe... Mud pumping in subgrade beds under ballastless tracks will deteriorate the dynamic performance of infrastructure under railway lines,reduce the smoothness of the railway lines,and seriously affect the comfort and safety of the trains.Due to their good mechanical properties,twocomponent polyurethane materials can be used for grouting to treat the fouling problems caused by ballastless track mud pumping.To develop a polyurethane formula suitable for the treatment of ballastless track mud pumping,we first performed indoor experiments to investigate the mechanical properties and gelation time of polyurethane elastomers synthesized with different raw material composition ratios,to determine an optimal composition ratio of the raw materials.Then,we conducted a dynamic field test to verify the remediation effect of the polyurethane material fabricated according to the design ratio.The results showed that polyurethane grouting material with the selected design ratios improved the contact characteristics between the surface layer of the subgrade bed and the base plate in the area,coordinating the dynamic response between the track structure and the subgrade bed.Thus,the obtained polyurethane grouting material could be used to renovate mud pumping areas of ballastless tracks with a good treatment effect. 展开更多
关键词 Ballastless track Mud pumping Twocomponent polyurethane Proportioning design field dynamic test
下载PDF
Fuzzy robust path tracking strategy of an active pelagic trawl system with coordinated ship and winch regulation 被引量:2
9
作者 陈英龙 周华 +1 位作者 赵勇刚 侯交义 《Journal of Central South University》 SCIE EI CAS 2014年第1期167-179,共13页
A fuzzy robust path tracking strategy of an active pelagic trawl system with ship and winch regulation is proposed.First,nonlinear mathematic model of the pelagic trawl system was derived using Lagrange equation and f... A fuzzy robust path tracking strategy of an active pelagic trawl system with ship and winch regulation is proposed.First,nonlinear mathematic model of the pelagic trawl system was derived using Lagrange equation and further simplified as a low order model for the convenience of controller design.Then,an active path tracking strategy of pelagic trawl system was investigated to improve the catching efficiency of the target fish near the sea bottom.By means of the active tracking control,the pelagic trawl net can be positioned dynamically to follow a specified trajectory via the coordinated winch and ship regulation.In addition,considering the system nonlinearities,modeling uncertainties and the unknown exogenous disturbance of the trawl system model,a nonlinear robust H2 /H∞ controller based on Takagi-Sugeno(T-S) fuzzy model was presented,and the simulation comparison with linear robust H2 /H∞ controller and PID method was conducted for the validation of the nonlinear fuzzy robust controller.The nonlinear simulation results show that the average tracking error is 0.4 m for the fuzzy robust H2 /H∞ control and 125.8 m for the vertical and horizontal displacement,respectively,which is much smaller than linear H2 /H∞ controller and the PID controller.The investigation results illustrate that the fuzzy robust controller is effective for the active path tracking control of the pelagic trawl system. 展开更多
关键词 active pelagic trawl system robust H21H∞ path tracking control Takagi-Sugeno (T-S) nonlinear modeling ship andwinch regulation
下载PDF
EFFECT OF ENVIRONMENTAL FIELD ON TROPICAL CYCLONE TRACK AFTER LANDFALL FROM EAST CHINA SEA 被引量:1
10
作者 钟元 余晖 王东法 《Journal of Tropical Meteorology》 SCIE 2006年第2期201-204,共4页
The past few years have seen work on the maintenance and decaying mechanisms of tropical cyclones (TCs) over land. Statistic study has been on the landfall frequency and location of TCs and their maintenance, decayi... The past few years have seen work on the maintenance and decaying mechanisms of tropical cyclones (TCs) over land. Statistic study has been on the landfall frequency and location of TCs and their maintenance, decaying, transition, intensification and dissipation for the past 32 years and that (1) the deeper water accumulates on land, the more favorable it would be for the maintenance of low pressures and vast lakes, and the surface of large rivers and large- sized reservoirs can slow down the decaying of TC lows, (2) the descending and intrusion of cold air from mid- and upper- tropospheric and warm advection from lower troposphere are responsible for TCs transition; and (3) after landfall, TCs tend to accelerate towards areas of intense convection to the northwest, etc. Being mainly numerical simulation and diagnostic analyses for cases covering much detail and depth, most of the studies cannot tell anything in common about how TCs maintain and decay over land. There has been little work on the difference of land track of TCs, which travel with the underlying surface changing from sea to land. The energy supply from the tropical ocean is severely reduced or completely cut off on the one hand, rough land surface is both a blocking and frictional force for TCs to dissipate their energy on the other. In fact, landfall TCs can either maintain for only a few hours and cover a distance of less than 100 km or stay active tbr more than 100 hours and go as farther away as a few thousand km inland. Why do they differ so much? Why do TCs follow routes that differ dramatically when they land at or near the same sites with identical or similar underlying surface? It is obvious that the environmental field is one of the essential factors for TCs after landfall. The aim of this paper is to discuss the effect of the environmental field on TCs track over land and to know whicch, synoptic systems or factors play key roles in it so as to provide basis for the forecasting of land track of TCs after landfall. 展开更多
关键词 environmental field effect tropical cyclone track after landfall
下载PDF
Typhoon-induced wind waves in the northern East China Sea during two typhoon events:the impact of wind field and wave-current interaction 被引量:1
11
作者 Zhao LI Shuiqing LI +3 位作者 Yijun HOU Dongxue MO Jian LI Baoshu YIN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第3期934-949,共16页
We examined the influences of the wind fi eld and wave-current interaction(WCI)on the numerical simulation results of typhoon-induced wind waves in the northern East China Sea(NECS)using the coupled Simulating Waves N... We examined the influences of the wind fi eld and wave-current interaction(WCI)on the numerical simulation results of typhoon-induced wind waves in the northern East China Sea(NECS)using the coupled Simulating Waves Nearshore+Advanced Circulation(SWAN+ADCIRC)model.The simulations were performed during two typhoon events(Lekima and Muifa),and two widely used reanalysis wind fields,the Climate Forecast System Version 2(CFSv2)from the National Centers for Environmental Prediction(NCEP)and the fifth-generation European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis(ERA5),were compared.The results indicate that the ERA5 and CFSv2 wind fields both reliably reproduced the wind variations measured by in-situ buoys,and the accuracy of the winds from ERA5 were generally better than those from CFSv2 because CFSv2 tended to overestimate the wind speed and the simulated significant wave height(SWH),particularly the peak SWH.The WCI effects between the two wind field simulations were similar;these effects enhanced the SWH throughout the nearshore NECS during both typhoons but suppressed the SWH on the right side of the Typhoon Muifa track in the deep and off shore sea areas.In summary,variations in the water depth and current propagation direction dominate the modulation of wave height. 展开更多
关键词 wind field typhoon track significant wave height wave-current interaction the northern East China Sea
下载PDF
Surface current field and seasonal variability in the Kuroshio and adjacent regions derived from satellite-tracked drifter data 被引量:23
12
作者 HU Xiaomin XIONG Xuejun +2 位作者 QIAO Fangli GUO Binghuo LIN Xiaopei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2008年第3期11-29,共19页
The muhiyear averaged surface current field and seasonal variability in the Kuroshio and adjacent regions are studied. The data used are trajectories and (1/4) ° latitude by (1/4) ° longitude mean curren... The muhiyear averaged surface current field and seasonal variability in the Kuroshio and adjacent regions are studied. The data used are trajectories and (1/4) ° latitude by (1/4) ° longitude mean currents derived from 323 Argos drifters deployed by Chinese institutions and world ocean circulation experiment from 1979 to 2003. The results show that the Kuroshio surface path adapts well to the western boundary topography and exhibits six great turnings. The branching occurs frequently near anticyclonic turnings rather than near cyclonic ones. In the Luzon Strait, the surface water intrusion into the South China Sea occurs only in fall and winter. The Kuroshio surface path east of Taiwan, China appears nearly as straight lines in summer, fall, and winter, when anticyclonic eddies coexist on its right side; while the path may cyclonically turning in spring when no eddy exists. The Kuroshio intrusion northeast of Taiwan often occurs in fall and winter, but not in summer. The running direction, width and velocity of the middle segment of the Kuroshio surface currents in the East China Sea vary seasonally. The northward intrusion of the Kuroshio surface water southwest of Kyushu occurs in spring and fall, but not in summer. The northmost position of the Kuroshio surface path southwest of Kyushu occurs in fall, but never goes beyond 31 °N. The northward surface current east of the Ryukyu Islands exists only along Okinawa-Amami Islands from spring to fall. In particular, it appears as an arm of an anti- cyclonic eddy in fall. 展开更多
关键词 KUROSHIO surface current field satellite-tracked surface drifter seasonal variability
下载PDF
Calculation and Analysis for Temperature Field of Tank Track and Wheels
13
作者 毕小平 黄小辉 蒋陆德 《Defence Technology(防务技术)》 SCIE EI CAS 2010年第2期91-95,共5页
To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle... To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle wheel and track loop were obtained.The effect of factors,such as tank speed,environment temperature,sun radiant energy,ground deformation resistant and tank load,on the temperature of road wheel was studied.The sensitivity analysis shows that the effect of tank load on the temperature is the most,and the effect of ground deformation resistant is the least.The temperature testing device for road wheel on tank was developed to perform the experiments in real time.The calculated temperatures are in accord well with the experimental values. 展开更多
关键词 engineering thermophysics track and wheel temperature field CALCULATION sensitivity analysis
下载PDF
Analysis on Thermal Current Field in Powertrain Cabin of Tracked Vehicles With Electric Transmission System Configuration-2 被引量:1
14
作者 张豫南 李瀚飞 +4 位作者 颜南明 尚颖辉 王冬 李源 袁文涛 《Defence Technology(防务技术)》 SCIE EI CAS 2007年第1期1-6,共6页
The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehicles. The geometrical model for the power-train cabin is established and the preliminary design for its cooling syst... The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehicles. The geometrical model for the power-train cabin is established and the preliminary design for its cooling system is implemented. The mathematic model is established for thermal current field computation, simulation and analysis in the powertrain cabin. The three-dimensional structure of the powertrain cabin is optimized. The validity of the cooling system design is proved. The foundation for optimizing the whole electric transmission system configuration is laid. 展开更多
关键词 履带车辆 电传动系统 电传系舱室 热流场 结构优化 数学模型
下载PDF
Investigation and Research on the Ordinary University High Level Track and Field Sports Teams in Sichuan Province
15
作者 Dawei Li Bin Wang 《Open Journal of Applied Sciences》 2012年第4期148-153,共6页
by using the method of literature, questionnaire and mathematical statistics and comparative analysis and ?research method of sichuan university high level survey of the Track and field team, sichuan university high l... by using the method of literature, questionnaire and mathematical statistics and comparative analysis and ?research method of sichuan university high level survey of the Track and field team, sichuan university high level Track and field team and the analysis of existing problems and research, in order to sichuan university of high level Track and field teams development to provide the reference. 展开更多
关键词 SICHUAN Ordinary UNIVERSITY the high leve track and field TEAM RESEARCH
下载PDF
Common Sports Injuries and Preventive Measures for Athletes—Take The Track and Field Team Athletes in Yushan County as an Example
16
作者 Jieqiong Xie 《教育研究前沿(中英文版)》 2019年第4期313-317,共5页
Taking the common sports injuries and preventive measures of Yushan County middle school track and field athletes as the research object,the sports injuries of Yushan County middle school track and field athletes were... Taking the common sports injuries and preventive measures of Yushan County middle school track and field athletes as the research object,the sports injuries of Yushan County middle school track and field athletes were investigated and analyzed from the angle,type,location and nature of sports injury.Research on sports injury problems,trying to find the causes of sports injuries in daily training of track and field athletes,and proposed targeted preventive measures based on the specific situation of Yushan County Middle School.The results show that 77.70%of track and field athletes have suffered sports injury and periostitis and ligament/muscle strains are the most common forms of injury,and lower limbs are more prone to sports injuries than upper limbs. 展开更多
关键词 Middle School track and field Sports Injuries Preventive Measures
下载PDF
Discussion on the Core Strength Training Method for 100-Meter Event in Track and Field Sports
17
作者 Jiachen Bian 《Journal of Contemporary Educational Research》 2023年第12期203-208,共6页
In track and field sports,the 100-meter race is an extremely intense sport that requires effective training of athletes’core strength.From the perspective of adolescents,in order to enhance core strength,it is necess... In track and field sports,the 100-meter race is an extremely intense sport that requires effective training of athletes’core strength.From the perspective of adolescents,in order to enhance core strength,it is necessary to effectively fix the pelvic position in the process of exercise,so that the core stability,balance,and coordination of athletes can be improved.The training process of the 100-meter event is mainly an anaerobic metabolic exercise,it is necessary to ensure that athletes maintain a high level of physical readiness during the exercises and concentrate highly on their core strength,so that they can achieve excellent results.This paper analyzes the core strength training for the 100-meter event in track and field sports,discusses its importance,and puts forward specific training methods,hoping to provide guidelines for relevant researchers. 展开更多
关键词 track and field sports 100-meter event Core strength Training methods
下载PDF
Study of the retina algorithm on FPGA for fast tracking 被引量:2
18
作者 Zi-Xuan Song Wen-Di Deng +5 位作者 Gilles De Lentdecker Guang-Ming Huang Hua Pei Yi-Fan Yang Dong Wang Frederic Robert 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第8期84-91,共8页
Real-time track reconstruction in high-energy physics experiments at colliders running at high luminosity is very challenging for trigger systems. To perform pattern recognition and track fitting, artificial retina or... Real-time track reconstruction in high-energy physics experiments at colliders running at high luminosity is very challenging for trigger systems. To perform pattern recognition and track fitting, artificial retina or Hough transformation algorithms have been introduced to the field typically implemented on state-of-the-art field programmable gate array(FPGA) devices. In this paper, we report on two FPGA implementations of the retina algorithm: one using a mixed Floating-Point core and the other using Fixed-Point and Look-Up Table, and detailed measurements of the retina performance are investigated and compared. So far, the retina has mainly been used in a detector configuration comprising parallel planes, and the goal of our work is to study the hardware implementation of the retina algorithm and estimate the possibility of using such a method in a real experiment. 展开更多
关键词 Fast trackING field PROGRAMMABLE GATE ARRAY TRIGGER
下载PDF
Design and tests of the prototype a beam monitor of the CSR external target experiment 被引量:6
19
作者 Hu-Lin Wang Zhen Wang +21 位作者 Chao-Song Gao Jian-Wei Liao Xiang-Ming Sun Hai-Bo Yang Cheng-Xin Zhao Jun Liu Peng Ma Zi-Li Li Bi-Hui You Ping Yang Di Guo Le Xiao Dong-Liang Zhang Yue-Zhao Zhang Sheng Dong Wan-Han Feng Yu-Xin Qiao Zheng-Yu Hu Qing-Wen Ye Zeng-Tao Guo Guang-Ming Huang Feng Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第3期137-151,共15页
A prototype beam monitor was designed to provide tracking information for heavy-ion projectiles for the cool storage ring(CSR)external target experiment(CEE)at the Heavy Ion Research Facility in Lanzhou(HIRFL).High gr... A prototype beam monitor was designed to provide tracking information for heavy-ion projectiles for the cool storage ring(CSR)external target experiment(CEE)at the Heavy Ion Research Facility in Lanzhou(HIRFL).High granularity and direct charge sensing are the main features of this device.It measures the beam position in a two-dimensional(2D)plane transverse to the beam direction on an event-by-event basis.The current design consists of two field cages inside a single vessel that operates independently and has electrical drift fields in orthogonal directions.Preliminary tests of the prototype were performed using a^(241)Am a source.The results show that a spatial resolution of less than 40μm and a time resolution of less than 600 ns can be achieved. 展开更多
关键词 CEE Beam monitor Heavy ion Topmetal sensor tracking field cage
下载PDF
A GOCE only gravity model GOSG01S and the validation of GOCE related satellite gravity models 被引量:8
20
作者 Xinyu Xu Yongqi Zhao +1 位作者 Tilo Reubelt Robert Tenzer 《Geodesy and Geodynamics》 2017年第4期260-272,共13页
We compile the GOCE-only satellite model GOSG01S complete to spherical harmonic degree of 220 using Satellite Gravity Gradiometry (SGG) data and the Satellite-to-Satellite Tracking (SST) observations along the GOC... We compile the GOCE-only satellite model GOSG01S complete to spherical harmonic degree of 220 using Satellite Gravity Gradiometry (SGG) data and the Satellite-to-Satellite Tracking (SST) observations along the GOCE orbit based on applying a least-squares analysis. The diagonal components (Vxx, Vyy, Vzz) of the gravitational gradient tensor are used to form the system of observation equations with the band-pass ARMA filter. The point-wise acceleration observations (ax, ay, az) along the orbit are used to form the system of observation equations up to the maximum spherical harmonic degree/order 130. The analysis of spectral accuracy characteristics of the newly derived gravitational model GOSG01S and the existing models GOTIM04S, GODIR04S, GOSPW04S and JYY_GOCE02S based on their comparison with the ultrahigh degree model EIGEN-6C2 reveals a significant consistency at the spectral window approximately between 80 and 190 due to the same period SGG data used to compile these models. The GOCE related satellite gravity models GOSG01S, GOTIM05S, GODIR05S, GOTIM04S, GODIR04S, GOSPW04S, JYY_- GOCE02S, EIGEN-6C2 and EGM2008 are also validated by using GPS-leveling data in China and USA. According to the truncation at degree 200, the statistic results show that all GGMs have very similar differences at GPS-leveling points in USA, and all GOCE related gravity models have better performance than EGM2008 in China. This suggests that all these models provide much more information on the gravity field than EGM2008 in areas with low terrestrial gravity coverage. And STDs of height anomaly differences in China for the selected truncation degrees show that GOCE has improved the accuracy of the global models beyond degree 90 and the accuracies of the models improve from 24 cm to 16 cm. STDs of geoid height differences in USA show that GOSG01S model has best consistency comparing with GPSleveling data for the frequency band of the degree between 20 and 160. 展开更多
关键词 Earth's gravity field Geopotential model Gravity gradient Validation SateLlite-to-satellite tracking
下载PDF
上一页 1 2 220 下一页 到第
使用帮助 返回顶部