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A new calibration method for radon detector in seismic systems
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作者 Hongwei Ren Yaowei Liu 《Earthquake Science》 2024年第5期445-458,共14页
Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector ... Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon sources.As a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in China.To solve this problem,a new calibration method for radon detectors was established.The advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector calibration.This method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in China.The comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new method.This new method can completely replace the traditional calibration method of using a radon source in seismic systems. 展开更多
关键词 radon detector CALIBRATION “standard instrument” scintillation chamber radon source
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Design and application of an autonomous Master Control System for a multi-layer magnetic and helioseismic telescope
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作者 Liyue Tong Yingzi Sun +8 位作者 Xiao Yang Jiaben Lin Yuanyong Deng Xianyong Bai Bingxiang Wang Xiaoming Zhu Yang Bai Yi Shang Hui Wang 《Astronomical Techniques and Instruments》 CSCD 2024年第3期187-196,共10页
With the growing significance of space weather forecasting,multi-layer magnetic and helioseismic telescopes are emerging as a key area of research.However,owing to the diverse operational processes and sophisticated h... With the growing significance of space weather forecasting,multi-layer magnetic and helioseismic telescopes are emerging as a key area of research.However,owing to the diverse operational processes and sophisticated hardware configurations of these devices,there is an urgent need for efficient autonomous observation capabilities.An autonomous Master Control System(MCS)can ensure efficient performance,data consistency,and stability,and the prototype presented here adopts a microservices architecture,breaking down the hardware into multiple subsystems and converting their functions into individual services.A central decision-making system leads the operations,supported by three auxiliary systems and three device control systems.Through inter-subsystem service calls,it achieves rapid imaging and spectroscopic monitoring.To verify system stability and observation efficiency,the system was tested on the Solar Full-disk Multi-layer Magnetograph.Experimental results verify this system can operate automatically for 4 consecutive months,acquire photospheric vector magnetic and Doppler velocity fields within a 15-minute interval,and measure chromospheric longitudinal magnetic and Doppler velocity fields in under 180 s.This ensures consistent and stable solar monitoring and serves as a practical methodological benchmark for the development of similar devices. 展开更多
关键词 Astronomical instrumentation Telescopes Solar optical telescopes Automated telescopes
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Research on the strain gauge mounting scheme of track wheel force measurement system based on high-speed wheel/rail relationship test rig
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作者 Yuanwu Cai Bo Chen Chongyi Chang 《Railway Sciences》 2024年第4期503-513,共11页
Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/appro... Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system. 展开更多
关键词 Track wheel High-speed wheel/rail relationship test rig Instrumented wheelset Strain gauge Finite element
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Instrument Automation Control System Faults and Maintenance
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作者 Jianwei Li 《Journal of Electronic Research and Application》 2024年第1期16-21,共6页
This article explores the topic of fault diagnosis and maintenance strategies for instrument automation control systems,analyzing them through specific cases.The aim of this research is to improve the stability and re... This article explores the topic of fault diagnosis and maintenance strategies for instrument automation control systems,analyzing them through specific cases.The aim of this research is to improve the stability and reliability of the system by conducting a thorough investigation of faults and maintenance in instrument automation control systems.By doing so,this research hopes to provide a strong guarantee for the smooth progress of industrial production. 展开更多
关键词 Instrument automation Control system failure Maintenance
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Distributed Control Software for the Active Surface System of Tian-ma Radio Telescope
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作者 Dong Zhang Rong-Bing Zhao +9 位作者 Zhen Yan Wei-Hua Shang-Guan Qian Ye Zhi-Qiang Shen Qing-Hui Liu Jin-Qing Wang Li Fu Chu-Yuan Zhang Dong-Fang Song Si-Yu Liu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第11期225-231,共7页
The Tian-ma Radio Telescope(TMRT) applies an Active Surface System(ASFS), which corrects for large-scale deformations due to gravity and thermal on the primary reflector. The centralized and automated management of th... The Tian-ma Radio Telescope(TMRT) applies an Active Surface System(ASFS), which corrects for large-scale deformations due to gravity and thermal on the primary reflector. The centralized and automated management of the ASFS using software has become a challenge, for which we have developed the TMRT Active Surface System Control Software(TASCS). This paper describes the design and implementation of TASCS for device control,status monitoring, human-computer interaction, and data management functionalities. TASCS adopts the opensource Tango Controls framework and distributes middleware technology to realize real-time automated adjustment of the primary reflector through remote centralized control of a large number of actuators. At present, it has been successfully deployed on the TMRT and has played an important role in Event Horizon Telescope observations. 展开更多
关键词 Astronomical Instrumentation Methods and Techniques telescopes instrumentation:high angular resolution techniques:high angular resolution
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Cost-effectiveness of patient specific vs conventional instrumentation for total knee arthroplasty:A systematic review and meta-analysis
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作者 Isobel M Dorling Lars Geenen +3 位作者 Marion J L F Heymans Jasper Most Bert Boonen Martijn G M Schotanus 《World Journal of Orthopedics》 2023年第6期458-470,共13页
BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness ... BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation(CI)for TKA.AIM To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.METHODS A literature search was performed in healthcare,economical healthcare,and medical databases(MEDLINE,EMBASE,CINAHL,Web of Science,Cochrane Library,EconLit).It was conducted in April 2021 and again in January 2022.Relevant literature included randomised controlled trials,retrospective studies,prospective studies,observational studies,and case control studies.All studies were assessed on methodological quality.Relevant outcomes included incremental cost-effectiveness ratio,quality-adjusted life years,total costs,imaging costs,production costs,sterilization associated costs,surgery duration costs and readmission rate costs.All eligible studies were assessed for risk of bias.Meta-analysis was performed for outcomes with sufficient data.RESULTS Thirty-two studies were included into the systematic review.Two were included in the metaanalysis.3994 PSI TKAs and 13267 CI TKAs were included in the sample size.The methodological quality of the included studies,based on Consensus on Health Economic Criteria-scores and risk of bias,ranged from average to good.PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case.PSI TKA costs more compared to CI TKA when considering imaging and production costs.Considering total costs per patient case,PSI TKA is more expensive in comparison to CI TKA.Meta-analysis comparing total costs for PSI TKA,and CI TKA showed a significant higher cost for PSI TKA.CONCLUSION Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation.Total costs per patient case are increased for PSI TKA when compared to CI TKA. 展开更多
关键词 Total knee arthroplasty Patient specific instrumentation Instrumentation for total knee arthroplasty COST-EFFECTIVENESS systematic review
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Environmental Impact Assessment System and Process in Developing Countries
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作者 Ramesh Prasad Bhatt 《Open Journal of Ecology》 2023年第12期977-1009,共33页
Environmental impact assessment (EIA), a decision-making process for project appraisal and sustainability adopted globally as an administrative process to identify, predict, evaluate, and monitor projects from their f... Environmental impact assessment (EIA), a decision-making process for project appraisal and sustainability adopted globally as an administrative process to identify, predict, evaluate, and monitor projects from their feasibility, preconstruction, construction, and operation stages to mitigate the adverse impacts and enhance the beneficial impacts for the protection of the affected environment, The study objective is to explore global EIA systems and processes and find shortcomings and implications for making the best instrument or tool to protect the natural environment from man-made activities over the project cycle. For this, the relevant literature on the EIA system and process was reviewed and evaluated through the application of quantitative and qualitative approaches, including the assessment of legal instruments and the adoption of EIA methodologies in developing countries. EIA, initiated in the 1970s in the US and Australia, expanded to developing countries and was amended in East and Southeast Asia from the 1970s to the 2000s. The evaluation assessed that the South Asian countries follow UNEP and IAIA guidelines, utilizing national laws and expert consultations, with screening criteria and administrative processes based on established environmental legislation. Ad hoc, checklist, matrix, network, overlay, cost-benefit analysis, and predictive or simulation in EIA practice are used to assess the environmental impacts of development activities. Failure to recommend major projects undermines public trust and prevents mitigation measures from being implemented. Most developing countries have followed EIA to fulfill the legal requirement with shadow-off monitoring and follow-up rather than to upset, reduce, or compensate for the project impacts as per size, location, and severity of the project area. The research and guidelines outlined in the IAIA principles and process have synthesized the best EIA practices worldwide. Public participation, impact coverage, scientific mitigation, transparent evidence-based approaches, monitoring, follow-up, legitimate approaches, and future appraisal opportunities are major concerns to be included in best EIA practice. 展开更多
关键词 EIA Process and Practice Evolution Developing Countries Legal Instruments IMPLICATIONS
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ArtiSentialTM Revolutionizes Traditional Laparoscopy in Urology by Introducing the Dexterity of a Robotic System to a Laparoscopic Instrument —First Experiences in Urology in Europe by the Ukrb in Neuruppin
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作者 Jens Cordes Lydia Bethge +5 位作者 Mujahed Amria Majed Ghazi Erich Seidel Arevalo Hazem Alhanini Sven Rauter Mohamed Awad 《Open Journal of Urology》 2023年第1期30-35,共6页
We describe the first two conventional, laparoscopic renal operations with a new multi-degree of freedom articulated single-use laparoscopic instrument (ArtiSential<sup>TM</sup>). The two patients underwen... We describe the first two conventional, laparoscopic renal operations with a new multi-degree of freedom articulated single-use laparoscopic instrument (ArtiSential<sup>TM</sup>). The two patients underwent different laparoscopic interventions at Ukrb University (Neuruppin, Germany): nephrectomy and Anderson-Hynes-pyeloplasty. All procedures were completed, with no need for conversion or placement of additional ports. No intraoperative complications or technical failure of the instrument was recorded. The mean operative time was 180 min median length of stay was 11.5 d. The instrument could be opened out of the sterile packaging and used at once when it was needed, because it is a single-use instrument. There was real haptical feedback and the costs are minimal compared to robot surgery. The use was straightforward and rapid processes after an intensive training of 4 h in a dry lap. Awaiting future investigations in larger series, this study proves the safety and feasibility of renal surgery with ArtiSential<sup>TM</sup> and provides relevant data that may help early adopters of this surgical instrument. 展开更多
关键词 Renal Cancer Renal Surgery Laparoscopic Surgery New Multi-Degree Instrument Single-Use
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Comparative Study of the Complications of Pedicular Screw Fixation Techniques in the Thoracolumbar Spine: A Systematic Review
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作者 Vanessa Cavazana Takata João Vitor Lois Balestrieri +4 位作者 Pedro Bastos Neto Rodrigo Eduardo Souza Garcia Idiberto José Zotarelli Filho Luis Fernando Ricci Boer Fabiano Morais Nogueira 《Open Journal of Orthopedics》 2023年第8期343-353,共11页
Introduction: The use of pedicle screws increases postoperative stability and consolidation of arthrodesis. Pedicle arthrodesis is currently the standard treatment for the thoracolumbar spine, presenting the best fusi... Introduction: The use of pedicle screws increases postoperative stability and consolidation of arthrodesis. Pedicle arthrodesis is currently the standard treatment for the thoracolumbar spine, presenting the best fusion and stiffness rates, and among its main indications is the possibility of better correction of spine deformities in the thoracic and lumbar region. However, due to different definitions and the lack of a control group, many of these studies have limited comparative analysis, resulting in the scarcity of comparative studies with standardized methodology. Objective: It was to analyze, through a systematic review, the safety and efficacy of instrumentation with pedicle screws in the spine which have been questioned, despite its wide use for stabilization of the spine, comparing the complications present in the insertion techniques of pedicle screws. Methods: The rules of the Systematic Review-PRISMA were followed. The literary search process was carried out from January to March 2023. A bibliographic search was carried out in MEDLINE, PubMed, and Scielo for articles produced between 2001 and 2023. The quality of the studies was based on the GRADE instrument, and the risk of bias was analyzed according to the Cochrane instrument. The Cohen test (Funnel Plot) and The Heterogeneity Test (Chi-Square Test – X<sup>2</sup>) were performed, with p Results and Conclusion: A total of 134 articles were found. A total of 67 articles were evaluated in full and 12 were selected to compose the results of this systematic review. According to the GRADE instrument, most studies (X<sup>2</sup> = 90.2% > 50%) followed a controlled clinical study model and had a good methodological design, with p < 0.05. It was shown that poor positioning of pedicle screws is the most common cause of complications. The surgeon’s skills and the length and diameter of the pedicle screw can also affect the different modes of placement. Robotic computer assistance has the potential to reduce the incidence of postoperative revisions. Minimally invasive techniques have contributed to the reduction of surgical trauma and complications, thus allowing patients who had restrictions on performing the surgical approach, such as the elderly and critically ill patients, to undergo surgical treatment. 展开更多
关键词 Pedicular Arthrodesis COMPLICATIONS Spinal Instrumentation
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Stand-Alone Patient Reception and Referral System with Health Data Management
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作者 Ababacar Sadikh Faye Ousmane Sow +3 位作者 Mame Andallah Diop Jupiter Ndiaye Youssou Traore Oumar Diallo 《Engineering(科研)》 2023年第10期596-611,共16页
The COVID-19 pandemic has exposed vulnerabilities within our healthcare structures. Healthcare facilities are often faced with staff shortages and work overloads, which can have an impact on the collection of health d... The COVID-19 pandemic has exposed vulnerabilities within our healthcare structures. Healthcare facilities are often faced with staff shortages and work overloads, which can have an impact on the collection of health data and constants essential for early diagnosis. In order to minimize the risk of error and optimize data collection, we have developed a robot incorporating artificial intelligence. This robot has been designed to automate and collect health data and constants in a contactless way, while at the same time verifying the conditions for correct measurements, such as the absence of hats and shoes. Furthermore, this health information needs to be transmitted to services for processing. Thus, this article addresses the aspect of reception and collection of health data and constants through various modules: for taking height, temperature and weight, as well as the module for entering patient identification data. The article also deals with orientation, presenting a module for selecting the patient’s destination department. This data is then routed via a wireless network and an application integrated into the doctors’ tablets. This application will enable efficient queue management by classifying patients according to their order of arrival. The system’s infrastructure is easily deployable, taking advantage of the healthcare facility’s local wireless network, and includes encryption mechanisms to reinforce the security of data circulating over the network. In short, this innovative system will offer an autonomous, contactless method for collecting vital constants such as size, mass, and temperature. What’s more, it will facilitate the flow of data, including identification information, across a network, simplifying the implementation of this solution within healthcare facilities. 展开更多
关键词 Public Health Health Data Wireless Network SECURITY Artificial Intelligence INSTRUMENTATION MECHATRONICS
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The CCD instrument background of the SMILE SXI 被引量:2
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作者 M.W.J.Hubbard O.Hetherington +6 位作者 D.J.Hall T.W.Buggey S.Parsons T.Arnold A.Holland C.Pagani S.Sembay 《Earth and Planetary Physics》 EI CSCD 2024年第1期15-24,共10页
The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrou... The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes. 展开更多
关键词 instrument background X-ray astronomy space radiation
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Field testing of the surface electromagnetic prospecting system 被引量:2
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作者 底青云 付长民 +3 位作者 安志国 许诚 王亚璐 王中兴 《Applied Geophysics》 SCIE CSCD 2017年第3期449-458,462,共11页
To test the performance of the Chinese whole-surface electromagnetic prospecting (SEP) system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mong... To test the performance of the Chinese whole-surface electromagnetic prospecting (SEP) system, system integrations, instrument performances, and large-scale production viabilities in Liaoning province and Inner Mongolia were measured via extensive field tests. Resultant electric fields, magnetic fields, apparent resistivities, impedance phases, and inversion profiles compared favorably with results of commercial equipment from other countries. The inversion results agreed well with the geologic information from boreholes. Field tests showed that the SEP system is stable, reliable, lightweight, and easy to operate, making it suitable and ready for real-field exploration. 展开更多
关键词 ground electromagnetic instrument electromagnetic sounding system SEP CSAMT
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Identification algorithm for a kind of fractional order system 被引量:5
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作者 王振滨 曹广益 朱新坚 《Journal of Southeast University(English Edition)》 EI CAS 2004年第3期297-302,共6页
The state-space representation of linear time-invariant (LTI) fractional order systems is introduced, and a proof of their stability theory is also given. Then an efficient identification algorithm is proposed for tho... The state-space representation of linear time-invariant (LTI) fractional order systems is introduced, and a proof of their stability theory is also given. Then an efficient identification algorithm is proposed for those fractional order systems. The basic idea of the algorithm is to compute fractional derivatives and the filter simultaneously, i.e., the filtered fractional derivatives can be obtained by computing them in one step, and then system identification can be fulfilled by the least square method. The instrumental variable method is also used in the identification of fractional order systems. In this way, even if there is colored noise in the systems, the unbiased estimation of the parameters can still be obtained. Finally an example of identifying a viscoelastic system is given to show the effectiveness of the aforementioned method. 展开更多
关键词 fractional order systems state-space representation system identification fractional order Poisson filter least square method instrumental variable method
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Research on the Testing Methods of Instrumental System in the Marine Magnetic Survey 被引量:1
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作者 边刚 刘雁春 +2 位作者 于波 肖付民 卞光浪 《Marine Science Bulletin》 CAS 2007年第2期1-11,共11页
Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method br... Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results. 展开更多
关键词 Marine magnetic survey instrumental system testing method
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The Jiao Tong University Spectroscopic Telescope Project 被引量:1
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作者 JUST Team Chengze Liu +28 位作者 Ying Zu Fabo Feng Zhaoyu Li Yu Yu Hua Bai Xiangqun Cui Bozhong Gu Yizhou Gu Jiaxin Han Yonghui Hou Zhongwen Hu Hangxin Ji Yipeng Jing Wei Li Zhaoxiang Qi Xianyu Tan Cairang Tian Dehua Yang Xiangyan Yuan Chao Zhai Congcong Zhang Jun Zhang Haotong Zhang Pengjie Zhang Yong Zhang Yi Zhao Xianzhong Zheng Qingfeng Zhu Xiaohu Yang 《Astronomical Techniques and Instruments》 CSCD 2024年第1期16-30,共15页
The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic observations.The JUST primary mirror is composed of 18 hexagonal segments,each with a di... The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic observations.The JUST primary mirror is composed of 18 hexagonal segments,each with a diameter of 1.1 m.JUST provides two Nasmyth platforms for placing science instruments.One Nasmyth focus fits a field of view of 10′and the other has an extended field of view of 1.2°with correction optics.A tertiary mirror is used to switch between the two Nasmyth foci.JUST will be installed at a site at Lenghu in Qinghai Province,China,and will conduct spectroscopic observations with three types of instruments to explore the dark universe,trace the dynamic universe,and search for exoplanets:(1)a multi-fiber(2000 fibers)medium-resolution spectrometer(R=4000-5000)to spectroscopically map galaxies and large-scale structure;(2)an integral field unit(IFU)array of 500 optical fibers and/or a long-slit spectrograph dedicated to fast follow-ups of transient sources for multi-messenger astronomy;(3)a high-resolution spectrometer(R~100000)designed to identify Jupiter analogs and Earth-like planets,with the capability to characterize the atmospheres of hot exoplanets. 展开更多
关键词 Astronomical instrumentation Optical telescopes Large-scale structure of the universe Redshift surveys Time domain astronomy Exoplanet astronomy
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Underground vibration signal detection and processing system based on LabWindows/CVI 被引量:1
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作者 刘培珍 夏湖培 姚金杰 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第1期57-62,共6页
In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is respons... In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI (C vitual instrument), which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements. 展开更多
关键词 virtual instrument data processing and detection vibration signal LABWINDOWS/CVI
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The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner
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作者 Shaoxiong Guo Yan Yang +3 位作者 Yanbin Yin Yihu Tang Yang Tian Chao Zhai 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期212-222,共11页
With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a... With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper motors.However,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been tricky.To overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current fluctuation.This must be done while ensuring adequate resolution of the PWM generator.By employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power supply.The sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μm.Moreover,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive applications.This device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope. 展开更多
关键词 instrumentation:adaptive optics instrumentation:spectrographs proper motions reference systems
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Long-term Integration Ability of the Submillimeter Wave Astronomy Satellite(SWAS)Spectral Line Receivers
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作者 Bing-Ru Wang Di Li +4 位作者 Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Rudolf Schieder Gary J.Melnick 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期315-322,共8页
The Submillimeter Wave Astronomy Satellite(SWAS)was the first space telescope capable of high spectral resolution observations of terahertz spectral lines.We have investigated the integration ability of its two receiv... The Submillimeter Wave Astronomy Satellite(SWAS)was the first space telescope capable of high spectral resolution observations of terahertz spectral lines.We have investigated the integration ability of its two receivers and spectrometer during five and a half years of on-orbit operation.The CI,O_(2),H_(2)O,and^(13)CO spectra taken toward all observed Galactic sources were analyzed.The present results are based on spectra with a total integration time of up to 2.72×10~4hr(■10~8s).The noise in the spectra is generally consistent with that expected from the radiometer equation,without any sign of approaching a noise floor.This noise performance reflects the extremely stable performance of the passively cooled front end as well as other relevant components in the SWAS instrument throughout its mission lifetime. 展开更多
关键词 telescopes space vehicles:instruments instrumentation:miscellaneous ISM:lines and bands
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Ground-layer Adaptive Optics for the 2.5 m Wide-field and High-resolution Solar Telescope
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作者 Ying Yang Lan-Qiang Zhang +5 位作者 Nan-Fei Yan Jin-Sheng Yang Zhen Li Teng-Fei Song Xue-Jun Rao Chang-Hui Rao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期224-236,共13页
The 2.5 m wide-field and high-resolution solar telescope(WeHoST)is currently under developing for solar observations.WeHoST aims to achieve high-resolution observations over a super-wide field of view(FOV)of5′×5... The 2.5 m wide-field and high-resolution solar telescope(WeHoST)is currently under developing for solar observations.WeHoST aims to achieve high-resolution observations over a super-wide field of view(FOV)of5′×5′,and a desired resolution of 0.3″.To meet the scientific requirements of WeHoST,the ground-layer adaptive optics(GLAO)with a specially designed wave front sensing system is as the primary consideration.We introduce the GLAO configuration,particularly the wave front sensing scheme.Utilizing analytic method,we simulate the performance of both classical AO and GLAO systems,optimize the wave front sensing system,and evaluate GLAO performance in terms of PSF uniformity and correction improvement across whole FOV.The results indicate that,the classical AO will achieve diffraction-limited resolution;the suggested GLAO configuration will uniformly improve the seeing across the full 5′×5′FOV,reducing the FWHM across the axis FOV to less than0.3″(λ≥705 nm,r0≥11 cm),which is more than two times improvement.The specially designed wave front sensor schedule offers new potential for WeHoST’s GLAO,particularly the multi-FOV GLAO and the flexibility to select the detected area.These capabilities will significantly enhance the scientific output of the telescope. 展开更多
关键词 INSTRUMENTATION adaptive optics-instrumentation detectors-instrumentation high angular resolution-methods numerical-telescopes-Sun activity
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The Impact of Bias Row Noise to Photometric Accuracy:Case Study Based on a Scientific CMOS Detector
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作者 Li Shao Hu Zhan +4 位作者 Chao Liu Haonan Chi Qiuyan Luo Huaipu Mu Wenzhong Shi 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期228-246,共19页
We tested a new model of CMOS detector manufactured by the Gpixel Inc,for potential space astronomical application.In laboratory,we obtain some bias images under the typical application environment.In these bias image... We tested a new model of CMOS detector manufactured by the Gpixel Inc,for potential space astronomical application.In laboratory,we obtain some bias images under the typical application environment.In these bias images,clear random row noise pattern is observed.The row noise also contains some characteristic spatial frequencies.We quantitatively estimated the impact of this feature to photometric measurements,by making simulated images.We compared different bias noise types under strict parameter control.The result shows the row noise will significantly deteriorate the photometric accuracy.It effectively increases the readout noise by a factor of2-10.However,if it is properly removed,the image quality and photometric accuracy will be significantly improved. 展开更多
关键词 INSTRUMENTATION detectors-methods statistical-techniques image processing
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