The chromosome theory of inheritance was established during the three first decades of the 20th century. During the early stage of its substantiating, there were lots of puzzles and little evidence that could validate...The chromosome theory of inheritance was established during the three first decades of the 20th century. During the early stage of its substantiating, there were lots of puzzles and little evidence that could validate it. The cytological processes were obscure and several scientists maintained serious doubts concerning the existence of a connection between Mendel＇s principles and the behaviour of chromosomes during cell division. It was vital to associate an external, observable characteristic of the organism to a specific chromosome, and this was achieved when sex was connected to special chromosomes. At that time, however, some important scholars refused to accept or delayed acceptance of the conception that the hereditary factors （later called genes） were physical entities located along the chromosomes. Such was the case of Thomas Morgan （1866-1945） and William Bateson （186 I- 1926）. Their attitudes could be explained by considering the doubtful ground of the hypothesis at that time. It is more difficult, however, to understand the attitude of Edmund Beecher Wilson （1856-1939）. Being an expert in cytology he was acquainted with all the difficulties concerning the chromosome hypothesis. Nonetheless, from 1905 onward, he attributed little weight to the problems and dedicated a notable effort to obtaining evidence that could have grounded it. This paper analyses Wilson＇s attitude focusing on his studies from 1900 to 1915 and the scientific context of this period. This study led to the conclusion that Wilson＇s attitude could be explained in methodological terms by the adoption of an instrumentalist attitude, while Bateson and Morgan adopted a realistic perspective.展开更多
This work sought to examine the philosophical arguments of John Dewey’s theory of knowledge for practical gains.Hence,it sought to address the problem on how the current rave of entrepreneurship can be given a new di...This work sought to examine the philosophical arguments of John Dewey’s theory of knowledge for practical gains.Hence,it sought to address the problem on how the current rave of entrepreneurship can be given a new direction,especially from the perspective of ideas or theories matching with practice as inspired by Dewey’s instrumentalism.The method of conceptual and critical analysis,hermeneutics and inductive/deductive arguments are employed to achieve that aim.The major findings of the work are that entrepreneurial development must be engaged from an interdisciplinary matrix.Thus,this work is geared to translate John Dewey’s philosophy to business sustainability,management and gains.展开更多
The Si Tian project,designed to utilize 60 telescopes distributed across multiple sites in China,is a next-generation timedomain survey initiative.As a pathfinder for the Si Tian project,the Mini-Si Tian(MST)has been ...The Si Tian project,designed to utilize 60 telescopes distributed across multiple sites in China,is a next-generation timedomain survey initiative.As a pathfinder for the Si Tian project,the Mini-Si Tian(MST)has been proposed and implemented to test the Si Tian’s brain and data pipeline,and to evaluate the feasibility of its technology and science cases.Mounted at the Xinglong Observatory,the MST project comprises three 30 cm telescopes and has been operated since 2022 November.Each telescope of the MST possesses a large field of view,covering 2°.29×1°.53 FOV,and is equipped withg',r'andi'filters,respectively.Acting as the pioneer of the forthcoming Si Tian project,the MST is dedicated to the discovery of variable stars,transients,and outburst events,and has already obtained some interesting scientific results.In this paper,we will summarize the first-two-year operation of the MST project.展开更多
The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the re...The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the readout system is implemented using a frequency division multiplexing circuit system,coupled with an FFT design to enable the readout of MKID arrays.The system is characterized by its compact size,low cost,portability,and ease of further development.Together,these features have significant implications for the design and readout of terahertz MKID arrays,while simultaneously advancing both the theoretical and practical aspects of MKID technology.展开更多
Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate a...Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.展开更多
The Wide Field Survey Telescope(WFST)is located at 4200 m on Saishiteng Mountain in Lenghu,Qinghai Province,China.It features a primary mirror with a diameter of 2.5 m and a camera equipped with nine CCDs,providing a ...The Wide Field Survey Telescope(WFST)is located at 4200 m on Saishiteng Mountain in Lenghu,Qinghai Province,China.It features a primary mirror with a diameter of 2.5 m and a camera equipped with nine CCDs,providing a wide field of view of approximately 3×3 square degrees.Calibration parameters are essential to ensure the precision of astrometric observations with the WFST.These parameters are derived from geometric distortion(GD)and gaps through astrometric modeling and are subsequently validated via the Yao’An High Precision Telescope(YAHPT).The GD solutions show maximum distortions between 1.18 and 10.29 pixels for the WFST chips,with central chips exhibiting lower distortion.After applying the GD correction,the precision of the WFST reaches 4 mas.The interchip gaps of the WFST range from 1.922 mm to 7.765 mm,corresponding to 10μm/pixel,aligning with the design and measurements.The calibrated parameters guarantee that the WFST can perform highly accurate astrometric measurements.Furthermore,as the WFST undergoes updates,the parameter model remains consistently applicable.展开更多
The accuracy of thermal analysis measurements is critical to analyze material properties correctly,making the improvement of measurement precision and proper uncertainty analysis of test results absolutely essential.A...The accuracy of thermal analysis measurements is critical to analyze material properties correctly,making the improvement of measurement precision and proper uncertainty analysis of test results absolutely essential.As a primary thermal analysis instrument,the simultaneous thermal analyzer(STA)has unique advantages,which combines the functionalities of thermogravimetric(TG)analyzersand differential scanning calorimeters(DSC).However,the absence of standard quality control procedures has resulted in poor measurement reproducibility,low accuracy,and inadequate traceability of analytical results.This study utilized a multi-point temperature calibration method based on national certified reference materials to reduce instrument temperature indication errors.On this basis,we innovatively established a comprehensive quality control system encompassing laboratory environmental control,standard method selection,instrument performance verification,reference material traceability,and uncertainty analysis,thereby achieving standardized operational procedures for thermal analysis measurement.Taking the"determination of initial melting temperature of unknown substances"as a representative case study,a component resolution model for thermal analysis test uncertainty was developed.Through systematic analysis of both the reference material-introduced component and measurement repeatability component,complete traceability of test results was achieved.This approach ensures data validity and enhances the accuracy of test results.This provides crucial technical support and practical reference for the standardization of thermal analysis measurement procedure and assessment of result reliability.展开更多
https://www.sciencedirect.com/journal/energy-and-buildings/vol/336/suppl/C Volume 336,1 June 2025[OA](1)Advancing energy renovations through digitalisation:A critical review of EU policies and instruments by Sun-Ah Hw...https://www.sciencedirect.com/journal/energy-and-buildings/vol/336/suppl/C Volume 336,1 June 2025[OA](1)Advancing energy renovations through digitalisation:A critical review of EU policies and instruments by Sun-Ah Hwang,Sultan etin,Henk Visscher,et al,Article 115627.展开更多
When we learn about Chinese traditional culture,we can find many interesting things.One of them is a special musical instrument—Erhu.The Erhu is a two-stringed instrument played with a bow.People often call it the Ch...When we learn about Chinese traditional culture,we can find many interesting things.One of them is a special musical instrument—Erhu.The Erhu is a two-stringed instrument played with a bow.People often call it the Chinese violin or Chinese fiddle.It is one of the most famous and loved instruments in Chinese music.The Erhu has a small wooden body and a long neck.It is held on the lap,and the bow moves between the two strings to make music.展开更多
In the context of"high-quality development"construction,the establishment and operational status of the national-level scientific research platforms at provincial universities—specifically,the large-scale i...In the context of"high-quality development"construction,the establishment and operational status of the national-level scientific research platforms at provincial universities—specifically,the large-scale instrument sharing platforms—are critically linked to the production of scientific research outcomes and the development of interdisciplinary talents.This study focuses on the public platform of the State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization,aiming to innovate the management system,establish a technical platform,effectively integrate resources,and actively engage graduate students in the platform management.While ensuring the efficient operation of the large-scale instrument platform at state key laboratories,it offers a novel approach to cultivating graduate students into versatile talents.展开更多
Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from Jan...Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from January to October 2024,and quality nursing activities were implemented in the management of reusable instruments.The completion of quality indicators was analyzed.The instrument quality management scores,department satisfaction,and nurses’professional ability scores before and after nursing management were compared.Results:After nursing intervention,the qualified rates of initial cleaning and final cleaning of sterilization instruments were 99.66%and 100%,respectively.The qualified rate of packaging was 99.97%,the wet package rate was 0.1‰,the loading qualified rate was 99.88%,and the qualified rate of distribution was 99.99%.After nursing intervention,the nurses’instrument quality management scores,department satisfaction,and nurses’professional ability scores were all higher than those before nursing intervention(P<0.05).Conclusion:Quality nursing activities can improve the cleaning,packaging,and sterilization qualified rates of reusable instruments in the CSSD,enhance the effect of instrument quality management,obtain higher department satisfaction from nurses,cultivate their professional abilities,and possess significant nursing management advantages.展开更多
Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize ...Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.展开更多
In this article,we have modeled the astroclimatic parameters using data from the fifth reanalysis series(ERA5)from the European Centre for Medium-Range Weather Forecasts over the period 2010-2020.These data have been ...In this article,we have modeled the astroclimatic parameters using data from the fifth reanalysis series(ERA5)from the European Centre for Medium-Range Weather Forecasts over the period 2010-2020.These data have been projected onto the site of the Roque de los Muchachos Observatory(ORM).The analysis covers the main parameters influencing the quality of astronomical observation,notably the vertical profiles of temperature,potential temperature,and optical turbulence(C_(n)~2),as well as the vertical wind distributions and seasonal behaviors of atmospheric turbulence,which are treated in detail by specifying the wind speed at the 200 hPa level(V200).Around this level,the wind at high altitude presents moderate speeds and a generally stable direction,conditions favorable for adaptive optics.The thermal profiles show good agreement with standard atmospheric models,with a well-defined tropopause and a stable stratosphere,as well as the integrated parameters such as seeing(free and total),isoplanatic angle,and coherence time.The results reveal a stratified and stable atmosphere,with turbulence predominantly concentrated in the lower troposphere.The thermal profiles show a good agreement with standard atmospheric models,with a well-defined tropopause and a stable stratosphere.The seasonality of the astroclimatic parameters indicates conditions particularly favorable for observation during the winter months,with the median of free seeing,total seeing,isoplanatic angle and a coherence time as respectively 0″.48,0″.72,2″,and 6 ms.These results confirm the strong potential of ORM as a reference astronomical site,capable of hosting high-precision observation instruments.The methodological approach employed also provides a replicable basis for the characterization of other candidate sites for the installation of ground-based telescopes.As a preliminary study,this work establishes a scientific basis for further on-site monitoring and detailed characterization of the ORM site.展开更多
A leading position in the areas of testing,instrumentation and machine control has been established by members of the British Textile Machinery Association(BTMA)and a number of new developments in these fields will be...A leading position in the areas of testing,instrumentation and machine control has been established by members of the British Textile Machinery Association(BTMA)and a number of new developments in these fields will be showcased at this year’s ITMA Asia+CITME exhibition,which takes place in Singapore from October 28-31.“Many of our members are currently developing new technologies,either in-house or increasingly through joint projects,and there will be much to reveal by the time of ITMA Asia in Singapore,”says BTMA CEO Jason Kent.“Some of the most recent developments are really going beyond what has previously been possible.”展开更多
The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light pas...The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light passes can be regarded as a slit.If the infrared detectors are small in size,the width of the slit is also small,which will cause serious diffraction phenomena.If the widths of the view field diaphragm and the optical system are designed by geometric optics theory,the diffraction light cannot be fully received by the detectors,which will cause energy loss.Expanding the width of the view field diaphragm will introduce stray radiation.Meanwhile,spectrometer follow-up optics should be set in cold environments to reduce the infrared background of the instrument.Optical materials have different thermal characteristics,the optical and mechanical structures will deform at lowtemperature,and the cold view field diaphragm is installed at room temperature,so it is impossible to guarantee that the cold view field diaphragm remains in its design position when working at low-temperature.This paper solves the above problems by designing an adjustable cold view field diaphragm installed in its cryogenic vacuum chamber.The width and position of the view field diaphragm can be adjusted when working in cold temperatures,without opening the cryogenic vacuum chamber.Contrasting the interference signal obtained by the detectors in the adjustment process,the system can get the most suitable width and position of the cold view field diaphragm.The above works are based on the spectrometer used in the study named Accurate Infrared Magnetic Field Measurements of the Sun.展开更多
The double revolving fiber positioning technology employed in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)represents one of the most successful advancements in large-scale multiobjective spect...The double revolving fiber positioning technology employed in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)represents one of the most successful advancements in large-scale multiobjective spectroscopy.The precision of fiber positioning is crucial,as it directly impacts the observational efficiency of LAMOST.A critical component of the fiber positioning system is the closed-loop control system,which traditionally utilizes the light spot generated at fiber end.However,this study introduces a novel approach based on front-illuminated LAMOST focal plane image measurements.Unlike back-illumination,front-illumination does not necessitate internal lighting in the spectrograph,thus reducing light pollution and eliminating the need for additional photography.This method employs an artificial intelligence model to analyze images captured at the focal plane unit(FPU),using the image of the white ceramic head on the FPU as the data set for training,the model is capable of accurately measuring the fiber positions solely through front-illumination.Preliminary trials indicate that the measurement accuracy achieved using the frontillumination method is approximately 0."13.This level of precision meets the stringent fiber positioning accuracy requirement of LAMOST,set at 0."2.Furthermore,this novel approach demonstrates compatibility with LAMOST’s existing closed-loop fiber control system,offering potential for seamless integration and enhanced operational efficiency.展开更多
For some space radio telescopes,the orbit determination accuracy is not high enough,the time synchronization accuracy provided by the satellite platforms is low,and GNSS devices are not available.As a result,a traditi...For some space radio telescopes,the orbit determination accuracy is not high enough,the time synchronization accuracy provided by the satellite platforms is low,and GNSS devices are not available.As a result,a traditional method that relies on GNSS devices to obtain an initial clock offset followed by performing correlation with the calibration source may fail to obtain fringes.Moreover,a brutal force search across the 2D clock offset and fringe rate search plane is computationally expensive.In light of these challenges,we propose a novel time synchronization method that utilizes the spacecraft’s telemetry tone signal.This method employs frequency polynomials derived from Doppler tracking for fringe rotation during the correlation process.By aligning the frequency of the target station precisely with that of the reference station,it is only necessary to split the clock offset search range into multiple time windows,perform correlation for each window,and identify the window with the highest signal-to-noise ratio(SNR).The precise clock offset is determined by combining the residual delay with the initial offset.To validate the method,we observe the Tianwen-1 telemetry signal with the 4.5 m small telescope in the Tianma campus of Shanghai Astronomical Observatory and 40 m telescope in Kunming.The results demonstrate that our method can accurately determine clock offset for a time range as wide as±10 ms,with an SNR slightly higher than that achieved with the delay model.This method is suitable for wide-range time synchronization for space Very Long Baseline Interferometry observations,especially in scenarios involving small antennas with low sensitivity and poor orbit determination accuracy.展开更多
This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Science...This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Sciences.We evaluated the linearity,bias stability,and dark current of the camera.Utilizing the Johnson-Cousins Blue-Visible-Red-Infrared filter system and an Andor DZ936 charge-coupled device camera,we conducted extensive observations of Landolt standard stars to determine the color terms,atmospheric extinction coefficients,photometric zero-points,and the sky background brightness.The results indicate that this telescope demonstrates excellent performance in photometric calibration and good system performance overall,meeting the requirements for limited scientific research and teaching purposes.展开更多
Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for...Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for identifying bridge damping ratios using a two-axle,three-mass test vehicle,relying on wheel responses captured by only two mounted sensors.Damping ratio estimation formulas are derived using both the Hilbert Transform(HT)and Wavelet Transform(WT),with a consistent formulation that confirms accurate estimation is achievable with minimal instrumentation,particularly when addressing the support effect.A comparative analysis of the two signal processing techniques reveals the superior performance of WT in identifying bridge damping ratios.The effectiveness of the proposed procedure and formulas is validated through a detailed parametric study,demonstrating robustness across bridges with varying modal damping ratios and different spans using minimal sensors.Moreover,the present study shows that responses from only the first two spans of a multi-span bridge are sufficient for reliable damping estimation,underscoring the practicality and scalability of the procedure for structural health monitoring applications.展开更多
The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to ...The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.展开更多
文摘The chromosome theory of inheritance was established during the three first decades of the 20th century. During the early stage of its substantiating, there were lots of puzzles and little evidence that could validate it. The cytological processes were obscure and several scientists maintained serious doubts concerning the existence of a connection between Mendel＇s principles and the behaviour of chromosomes during cell division. It was vital to associate an external, observable characteristic of the organism to a specific chromosome, and this was achieved when sex was connected to special chromosomes. At that time, however, some important scholars refused to accept or delayed acceptance of the conception that the hereditary factors （later called genes） were physical entities located along the chromosomes. Such was the case of Thomas Morgan （1866-1945） and William Bateson （186 I- 1926）. Their attitudes could be explained by considering the doubtful ground of the hypothesis at that time. It is more difficult, however, to understand the attitude of Edmund Beecher Wilson （1856-1939）. Being an expert in cytology he was acquainted with all the difficulties concerning the chromosome hypothesis. Nonetheless, from 1905 onward, he attributed little weight to the problems and dedicated a notable effort to obtaining evidence that could have grounded it. This paper analyses Wilson＇s attitude focusing on his studies from 1900 to 1915 and the scientific context of this period. This study led to the conclusion that Wilson＇s attitude could be explained in methodological terms by the adoption of an instrumentalist attitude, while Bateson and Morgan adopted a realistic perspective.
文摘This work sought to examine the philosophical arguments of John Dewey’s theory of knowledge for practical gains.Hence,it sought to address the problem on how the current rave of entrepreneurship can be given a new direction,especially from the perspective of ideas or theories matching with practice as inspired by Dewey’s instrumentalism.The method of conceptual and critical analysis,hermeneutics and inductive/deductive arguments are employed to achieve that aim.The major findings of the work are that entrepreneurial development must be engaged from an interdisciplinary matrix.Thus,this work is geared to translate John Dewey’s philosophy to business sustainability,management and gains.
基金supported by the National Key R&D Program of China(grant No.2023YFA1608304 and No.2023YFA1608300)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550100 and XDB0550000)the National Natural Science Foundation of China(NSFC,grant Nos.12090041,12090040,11903054,12422303,and 12261141690)。
文摘The Si Tian project,designed to utilize 60 telescopes distributed across multiple sites in China,is a next-generation timedomain survey initiative.As a pathfinder for the Si Tian project,the Mini-Si Tian(MST)has been proposed and implemented to test the Si Tian’s brain and data pipeline,and to evaluate the feasibility of its technology and science cases.Mounted at the Xinglong Observatory,the MST project comprises three 30 cm telescopes and has been operated since 2022 November.Each telescope of the MST possesses a large field of view,covering 2°.29×1°.53 FOV,and is equipped withg',r'andi'filters,respectively.Acting as the pioneer of the forthcoming Si Tian project,the MST is dedicated to the discovery of variable stars,transients,and outburst events,and has already obtained some interesting scientific results.In this paper,we will summarize the first-two-year operation of the MST project.
基金funded by the National Key Research and Development Program of China under Nos.2023YFA1608200&2020YFC2201703the National Natural Science Foundation of China(NSFC,Grant No.12020101002)the Natural Science Foundation of China for the youth under No.12103093。
文摘The proposed design of a microwave superconducting kinetic inductance detector(MKID)array readout system characterizes the performance of MKIDs through a digital homodyne frequency mixing architecture.Meanwhile,the readout system is implemented using a frequency division multiplexing circuit system,coupled with an FFT design to enable the readout of MKID arrays.The system is characterized by its compact size,low cost,portability,and ease of further development.Together,these features have significant implications for the design and readout of terahertz MKID arrays,while simultaneously advancing both the theoretical and practical aspects of MKID technology.
文摘Instrument separation is a critical complication during root canal therapy,impacting treatment success and long-term tooth preservation.The etiology of instrument separation is multifactorial,involving the intricate anatomy of the root canal system,instrument-related factors,and instrumentation techniques.Instrument separation can hinder thorough cleaning,shaping,and obturation of the root canal,posing challenges to successful treatment outcomes.Although retrieval of separated instrument is often feasible,it carries risks including perforation,excessive removal of tooth structure and root fractures.Effective management of separated instruments requires a comprehensive understanding of the contributing factors,meticulous preoperative assessment,and precise evaluation of the retrieval difficulty.The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes.The current manuscript provides a framework for understanding the causes,risk factors,and clinical management principles of instrument separation.By integrating effective strategies,endodontists can enhance decision-making,improve endodontic treatment success and ensure the preservation of natural dentition.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0350300)the National Natural Science Foundation of China(12203105,12103091,62394351,12073008)the China Manned Space Project(CMS-CSST-2021-A12,CMS-CSST-2021-B10).
文摘The Wide Field Survey Telescope(WFST)is located at 4200 m on Saishiteng Mountain in Lenghu,Qinghai Province,China.It features a primary mirror with a diameter of 2.5 m and a camera equipped with nine CCDs,providing a wide field of view of approximately 3×3 square degrees.Calibration parameters are essential to ensure the precision of astrometric observations with the WFST.These parameters are derived from geometric distortion(GD)and gaps through astrometric modeling and are subsequently validated via the Yao’An High Precision Telescope(YAHPT).The GD solutions show maximum distortions between 1.18 and 10.29 pixels for the WFST chips,with central chips exhibiting lower distortion.After applying the GD correction,the precision of the WFST reaches 4 mas.The interchip gaps of the WFST range from 1.922 mm to 7.765 mm,corresponding to 10μm/pixel,aligning with the design and measurements.The calibrated parameters guarantee that the WFST can perform highly accurate astrometric measurements.Furthermore,as the WFST undergoes updates,the parameter model remains consistently applicable.
文摘The accuracy of thermal analysis measurements is critical to analyze material properties correctly,making the improvement of measurement precision and proper uncertainty analysis of test results absolutely essential.As a primary thermal analysis instrument,the simultaneous thermal analyzer(STA)has unique advantages,which combines the functionalities of thermogravimetric(TG)analyzersand differential scanning calorimeters(DSC).However,the absence of standard quality control procedures has resulted in poor measurement reproducibility,low accuracy,and inadequate traceability of analytical results.This study utilized a multi-point temperature calibration method based on national certified reference materials to reduce instrument temperature indication errors.On this basis,we innovatively established a comprehensive quality control system encompassing laboratory environmental control,standard method selection,instrument performance verification,reference material traceability,and uncertainty analysis,thereby achieving standardized operational procedures for thermal analysis measurement.Taking the"determination of initial melting temperature of unknown substances"as a representative case study,a component resolution model for thermal analysis test uncertainty was developed.Through systematic analysis of both the reference material-introduced component and measurement repeatability component,complete traceability of test results was achieved.This approach ensures data validity and enhances the accuracy of test results.This provides crucial technical support and practical reference for the standardization of thermal analysis measurement procedure and assessment of result reliability.
文摘https://www.sciencedirect.com/journal/energy-and-buildings/vol/336/suppl/C Volume 336,1 June 2025[OA](1)Advancing energy renovations through digitalisation:A critical review of EU policies and instruments by Sun-Ah Hwang,Sultan etin,Henk Visscher,et al,Article 115627.
文摘When we learn about Chinese traditional culture,we can find many interesting things.One of them is a special musical instrument—Erhu.The Erhu is a two-stringed instrument played with a bow.People often call it the Chinese violin or Chinese fiddle.It is one of the most famous and loved instruments in Chinese music.The Erhu has a small wooden body and a long neck.It is held on the lap,and the bow moves between the two strings to make music.
基金Supported by Quality Engineering Teaching Research Project of Anhui Agricultural University(2023aujyxm013,2023aujyxm002)Research Project on Quality Engineering Experimental Teaching and Teaching Laboratory Construction of Anhui Agricultural University(2024ausyyj002)Quality Engineering Teaching Research Project of Anhui Province(2020jyxm0504,2024jyxm0141).
文摘In the context of"high-quality development"construction,the establishment and operational status of the national-level scientific research platforms at provincial universities—specifically,the large-scale instrument sharing platforms—are critically linked to the production of scientific research outcomes and the development of interdisciplinary talents.This study focuses on the public platform of the State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization,aiming to innovate the management system,establish a technical platform,effectively integrate resources,and actively engage graduate students in the platform management.While ensuring the efficient operation of the large-scale instrument platform at state key laboratories,it offers a novel approach to cultivating graduate students into versatile talents.
文摘Objective:To evaluate the effectiveness of quality nursing in the management of reusable instruments in the Central Sterile Supply Department(CSSD).Methods:Eleven nurses from the CSSD department were selected from January to October 2024,and quality nursing activities were implemented in the management of reusable instruments.The completion of quality indicators was analyzed.The instrument quality management scores,department satisfaction,and nurses’professional ability scores before and after nursing management were compared.Results:After nursing intervention,the qualified rates of initial cleaning and final cleaning of sterilization instruments were 99.66%and 100%,respectively.The qualified rate of packaging was 99.97%,the wet package rate was 0.1‰,the loading qualified rate was 99.88%,and the qualified rate of distribution was 99.99%.After nursing intervention,the nurses’instrument quality management scores,department satisfaction,and nurses’professional ability scores were all higher than those before nursing intervention(P<0.05).Conclusion:Quality nursing activities can improve the cleaning,packaging,and sterilization qualified rates of reusable instruments in the CSSD,enhance the effect of instrument quality management,obtain higher department satisfaction from nurses,cultivate their professional abilities,and possess significant nursing management advantages.
基金supported by the National Key Research and Development Program of China(grants Nos.2022YFC2205000 and 2021YFC2203400)。
文摘Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.
文摘In this article,we have modeled the astroclimatic parameters using data from the fifth reanalysis series(ERA5)from the European Centre for Medium-Range Weather Forecasts over the period 2010-2020.These data have been projected onto the site of the Roque de los Muchachos Observatory(ORM).The analysis covers the main parameters influencing the quality of astronomical observation,notably the vertical profiles of temperature,potential temperature,and optical turbulence(C_(n)~2),as well as the vertical wind distributions and seasonal behaviors of atmospheric turbulence,which are treated in detail by specifying the wind speed at the 200 hPa level(V200).Around this level,the wind at high altitude presents moderate speeds and a generally stable direction,conditions favorable for adaptive optics.The thermal profiles show good agreement with standard atmospheric models,with a well-defined tropopause and a stable stratosphere,as well as the integrated parameters such as seeing(free and total),isoplanatic angle,and coherence time.The results reveal a stratified and stable atmosphere,with turbulence predominantly concentrated in the lower troposphere.The thermal profiles show a good agreement with standard atmospheric models,with a well-defined tropopause and a stable stratosphere.The seasonality of the astroclimatic parameters indicates conditions particularly favorable for observation during the winter months,with the median of free seeing,total seeing,isoplanatic angle and a coherence time as respectively 0″.48,0″.72,2″,and 6 ms.These results confirm the strong potential of ORM as a reference astronomical site,capable of hosting high-precision observation instruments.The methodological approach employed also provides a replicable basis for the characterization of other candidate sites for the installation of ground-based telescopes.As a preliminary study,this work establishes a scientific basis for further on-site monitoring and detailed characterization of the ORM site.
文摘A leading position in the areas of testing,instrumentation and machine control has been established by members of the British Textile Machinery Association(BTMA)and a number of new developments in these fields will be showcased at this year’s ITMA Asia+CITME exhibition,which takes place in Singapore from October 28-31.“Many of our members are currently developing new technologies,either in-house or increasingly through joint projects,and there will be much to reveal by the time of ITMA Asia in Singapore,”says BTMA CEO Jason Kent.“Some of the most recent developments are really going beyond what has previously been possible.”
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.11427901)。
文摘The infrared Fourier transform spectrometer needs a cold view field diaphragm to reduce stray radiation.For an infrared spectrometer with linear array detectors,the part of the view field diaphragm where the light passes can be regarded as a slit.If the infrared detectors are small in size,the width of the slit is also small,which will cause serious diffraction phenomena.If the widths of the view field diaphragm and the optical system are designed by geometric optics theory,the diffraction light cannot be fully received by the detectors,which will cause energy loss.Expanding the width of the view field diaphragm will introduce stray radiation.Meanwhile,spectrometer follow-up optics should be set in cold environments to reduce the infrared background of the instrument.Optical materials have different thermal characteristics,the optical and mechanical structures will deform at lowtemperature,and the cold view field diaphragm is installed at room temperature,so it is impossible to guarantee that the cold view field diaphragm remains in its design position when working at low-temperature.This paper solves the above problems by designing an adjustable cold view field diaphragm installed in its cryogenic vacuum chamber.The width and position of the view field diaphragm can be adjusted when working in cold temperatures,without opening the cryogenic vacuum chamber.Contrasting the interference signal obtained by the detectors in the adjustment process,the system can get the most suitable width and position of the cold view field diaphragm.The above works are based on the spectrometer used in the study named Accurate Infrared Magnetic Field Measurements of the Sun.
基金supported by NSFC under grant Nos.12073046 and 12261141689the project has been provided by the National Development and Reform Commission.
文摘The double revolving fiber positioning technology employed in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)represents one of the most successful advancements in large-scale multiobjective spectroscopy.The precision of fiber positioning is crucial,as it directly impacts the observational efficiency of LAMOST.A critical component of the fiber positioning system is the closed-loop control system,which traditionally utilizes the light spot generated at fiber end.However,this study introduces a novel approach based on front-illuminated LAMOST focal plane image measurements.Unlike back-illumination,front-illumination does not necessitate internal lighting in the spectrograph,thus reducing light pollution and eliminating the need for additional photography.This method employs an artificial intelligence model to analyze images captured at the focal plane unit(FPU),using the image of the white ceramic head on the FPU as the data set for training,the model is capable of accurately measuring the fiber positions solely through front-illumination.Preliminary trials indicate that the measurement accuracy achieved using the frontillumination method is approximately 0."13.This level of precision meets the stringent fiber positioning accuracy requirement of LAMOST,set at 0."2.Furthermore,this novel approach demonstrates compatibility with LAMOST’s existing closed-loop fiber control system,offering potential for seamless integration and enhanced operational efficiency.
基金supported by the National Key Research and Development Program of China(grant No.2022YFC2205203)the National Natural Science Foundation of China(grant No.42241118)+1 种基金the Strategic Pilot Study Program of the Chinese Academy of Sciences(grant No.XDB0800103)the Key Incubation Project of Shanghai Astronomical Observatory,CAS.
文摘For some space radio telescopes,the orbit determination accuracy is not high enough,the time synchronization accuracy provided by the satellite platforms is low,and GNSS devices are not available.As a result,a traditional method that relies on GNSS devices to obtain an initial clock offset followed by performing correlation with the calibration source may fail to obtain fringes.Moreover,a brutal force search across the 2D clock offset and fringe rate search plane is computationally expensive.In light of these challenges,we propose a novel time synchronization method that utilizes the spacecraft’s telemetry tone signal.This method employs frequency polynomials derived from Doppler tracking for fringe rotation during the correlation process.By aligning the frequency of the target station precisely with that of the reference station,it is only necessary to split the clock offset search range into multiple time windows,perform correlation for each window,and identify the window with the highest signal-to-noise ratio(SNR).The precise clock offset is determined by combining the residual delay with the initial offset.To validate the method,we observe the Tianwen-1 telemetry signal with the 4.5 m small telescope in the Tianma campus of Shanghai Astronomical Observatory and 40 m telescope in Kunming.The results demonstrate that our method can accurately determine clock offset for a time range as wide as±10 ms,with an SNR slightly higher than that achieved with the delay model.This method is suitable for wide-range time synchronization for space Very Long Baseline Interferometry observations,especially in scenarios involving small antennas with low sensitivity and poor orbit determination accuracy.
基金supported by National Key R&D Program of China(2023YFA1609700)Research and Education Integration Funding。
文摘This paper presents a comprehensive analysis of the photometric system of the University of Chinese Academy of Sciences 70 cm Telescope located at the Yan-qi Lake campus of the University of Chinese Academy of Sciences.We evaluated the linearity,bias stability,and dark current of the camera.Utilizing the Johnson-Cousins Blue-Visible-Red-Infrared filter system and an Andor DZ936 charge-coupled device camera,we conducted extensive observations of Landolt standard stars to determine the color terms,atmospheric extinction coefficients,photometric zero-points,and the sky background brightness.The results indicate that this telescope demonstrates excellent performance in photometric calibration and good system performance overall,meeting the requirements for limited scientific research and teaching purposes.
文摘Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for identifying bridge damping ratios using a two-axle,three-mass test vehicle,relying on wheel responses captured by only two mounted sensors.Damping ratio estimation formulas are derived using both the Hilbert Transform(HT)and Wavelet Transform(WT),with a consistent formulation that confirms accurate estimation is achievable with minimal instrumentation,particularly when addressing the support effect.A comparative analysis of the two signal processing techniques reveals the superior performance of WT in identifying bridge damping ratios.The effectiveness of the proposed procedure and formulas is validated through a detailed parametric study,demonstrating robustness across bridges with varying modal damping ratios and different spans using minimal sensors.Moreover,the present study shows that responses from only the first two spans of a multi-span bridge are sufficient for reliable damping estimation,underscoring the practicality and scalability of the procedure for structural health monitoring applications.
基金supported by the Natural Science Foundation of Fujian Province(No.2020J06008)for Distinguished Young Scholarsthe Fujian Provincial Central Guided Local Science and Technology Development Special Project(No.2022L3078).
文摘The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.
