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密近双星候选体LAMOST J051402.68+172659.7光谱分析
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作者 王琦 杨海峰 蔡江辉 《光谱学与光谱分析》 北大核心 2025年第5期1416-1421,共6页
密近双星系统通常具有更快速的轨道运动和更频繁的光变效应,以及伴星的快速演化,这使得它们成为研究星际物理过程和恒星演化的重要天体。测光图像和光变曲线是识别与证认双星的最常用手段,而如果当前观测技术无法分辨双目标的亮度和位... 密近双星系统通常具有更快速的轨道运动和更频繁的光变效应,以及伴星的快速演化,这使得它们成为研究星际物理过程和恒星演化的重要天体。测光图像和光变曲线是识别与证认双星的最常用手段,而如果当前观测技术无法分辨双目标的亮度和位置差异时,光谱型也是区分伴星成分的重要方法之一。采用基于粗集与聚类投票机制的光谱双星分析方法,对其离群目标LAMOST J051402.68+172659.7的光谱特征及其证认进行了深入分析。首先,针对LAMOST DR10发布的光谱双星(类别为DoubleStar),对其多次聚类结果投票数最低的17个目标光谱,进行了人眼筛查,除了大部分光谱信噪比较低外,LAMOST J051402.68+172659.7的两次观测光谱呈现较大差异;对于该目标的两次观测,其光谱一次呈现F型,一次呈现F+M型,在排除邻近光纤污染和目标所处环境中其他目标污染后,确定两次观测光谱上呈现的都是目标真实成分,揭示了两种光谱成分来自两个恒星目标;两次观测的视向速度相差约20.3 km·s-1,观测时隔3 d,说明其绕转周期小于6 d。考虑到多个目标成分在同一条光谱上同时出现的条件极其严苛:光谱型差异较大且亮度(流量)在同一尺度上,对其光谱成分、成像、光变等内容进行了深入分析。从ZTF测光的图像序列中,可以检测到目标轮廓的尺寸呈现周期性变化,而在ASAS-SN和ZTF光变曲线上,并未发现明显的周期性变化规律;同时,由于两个天体距离极近或投影掩盖,从SDSS、2MASS测光图像上,呈现出点源的特征(边界稍显不规则),无法分辨双星目标,因此该双星系统的两个恒星之间可能轨道较为紧密,半径较小;在其光谱上呈现Balmer弱发射线(Hα、Hβ、Hδ、Hγ)和禁线([NII]λ6550、[SII]λλ6718,6733、[OII]λ3728)且目标未在行星状星云或HII区域,推测是由伴星相互作用产生的潮汐效应和物质交换,从而对恒星表面和大气层带来冲击,产生发射线。此外,该目标光谱还呈现疑似背景星系的极弱发射线成分,从成像上无法分辨,推测其为数据处理残余。 展开更多
关键词 光谱双星 光变 恒星活动 郭守敬望远镜(lamost)
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A study on universal observation control system and its application for LAMOST
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作者 Zheng Wang Yuan Tian +2 位作者 Jian Li Zi-Huang Cao Yong-Heng Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第6期369-386,共18页
The observatory control system(OCS),a part of automated control of Large Sky Area MultiObject Fibre Spectroscopic Telescope(LAMOST),runs on the CentOS6 platform and implements the communication between modules based o... The observatory control system(OCS),a part of automated control of Large Sky Area MultiObject Fibre Spectroscopic Telescope(LAMOST),runs on the CentOS6 platform and implements the communication between modules based on Common Object Request Broker Architecture(CORBA).However,CORBA is complicated and has limited development support;moreover,the official support for CentOS6 has ended.OCS inherently has some shortcomings such as the over-concentration of control and the blocking of device status processing,which hinder the realization of automated observation control of LAMOST.Therefore,this study designs and implements a universal observation control system(UOCS)for optical telescopes.The UOCS takes the device command as the basic execution unit,controls the device execution logic using observation script,controls the observation logic by event-driven messaging,and realizes mutual decoupling between modules via a distributed control mode,thereby ensuring high system robustness.The UOCS performs significantly better than OCS in terms of the observation performance,operator complexity,and communication error.Currently,UOCS is applied to the automated control of some devices and subsystems in LAMOST observation.It will be applied to the automated observation control of Multi-channel Photometric Survey Telescope by 2021. 展开更多
关键词 telescopes techniques:miscellaneous methods:observational instrumentation:miscellaneous
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In-situ observation of nonmetallic inclusions in steel using confocal scanning laser microscopy:A review 被引量:2
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作者 Ying Ren Lifeng Zhang 《International Journal of Minerals,Metallurgy and Materials》 2025年第5期975-991,共17页
The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are revi... The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are reviewed and summarized,particularly the col-lision of various inclusions,dissolution of inclusions in liquid slag,and reactions between inclusions and steel.Solid inclusions exhibited a high collision tendency,whereas pure liquid inclusions exhibited minimal collisions because of the small attraction force induced by their<90°contact angle with molten steel.The collision of complex inclusions in molten steel was not included in the scope of this study and should be evaluated in future studies.Higher CaO/Al_(2)O_(3)and CaO/SiO_(2)ratios in liquid slag promoted the dissolution of Al_(2)O_(3)-based in-clusions.The formation of solid phases in the slag should be prevented to improve dissolution of inclusions.To accurately simulate the dissolution of inclusions in liquid slag,in-situ observation of the dissolution of inclusions at the steel-slag interface is necessary.Using a combination of CSLM and scanning electron microscopy-energy dispersive spectroscopy,the composition and morphological evolution of the inclusions during their modification by the dissolved elements in steel were observed and analyzed.Although the in-situ observa-tion of MnS and TiN precipitations has been widely studied,the in-situ observation of the evolution of oxide inclusions in steel during so-lidification and heating processes has rarely been reported.The effects of temperature,heating and cooling rates,and inclusion character-istics on the formation of acicular ferrites(AFs)have been widely studied.At a cooling rate of 3-5 K/s,the order of AF growth rate in-duced by different inclusions,as reported in literature,is Ti-O<Ti-Ca-Zr-Al-O<Mg-O<Ti-Zr-Al-O<Mn-Ti-Al-O<Ti-Al-O<Zr-Ti-Al-O.Further comprehensive experiments are required to investigate the quantitative relationship between the formation of AFs and inclusions. 展开更多
关键词 INCLUSION STEEL in-situ observation confocal scanning laser microscopy
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In-situ observation and analysis of high temperature behavior of carbides in GCr15 bearing steel by confocal laser scanning microscopy 被引量:2
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作者 Jun Ren Yue Teng +4 位作者 Xiang Liu Xi Xu Hui-gai Li Ke Han Qi-jie Zhai 《Journal of Iron and Steel Research International》 2025年第2期409-417,共9页
The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution ki... The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution kinetics of primary carbides during either heating or soaking.Dissolution of carbides proceeded in three stages(fast→slow→faster)as either temperature or holding time was increased.During the heating process and during the first and third stages of the soaking process,the original size of the carbides determined the steepness of the slope,but during the middle(“slow”)stage of the soaking process,the slope remained zero.The initial size of the carbides varied greatly,but their final dissolution temperature fell within the narrow range of 1210-1235℃,and the holding time remained within 50 min.Fractal analysis was used to study the morphological characteristics of small and medium-sized carbides during the dissolution process.According to changes in the fractal dimension before and after soaking,the carbides tended to evolve towards a more regular morphology. 展开更多
关键词 Bearing steel High-temperature confocal laser scanning microscope In-situ observation Primary carbide Fractal analysis
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Information carried by different magnetic observations:A review 被引量:1
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作者 David Gubbins 《Earth and Planetary Physics》 2025年第3期479-490,共12页
The Macao satellites differ from their predecessors in their orbits:MSS-1(Macao Science Satellite-1)is in low inclination and the planned MSS-2 will be in highly elliptical orbits.This paper reviews the fundamental ad... The Macao satellites differ from their predecessors in their orbits:MSS-1(Macao Science Satellite-1)is in low inclination and the planned MSS-2 will be in highly elliptical orbits.This paper reviews the fundamental advantages and disadvantages of the different possible magnetic measurements:the component(declination,intensity,etc.)and location(satellite,ground,etc.).When planning a survey the choice of component is the"What?"question;the choice of location the"Where?"question.Results from potential theory inform the choice of measurement and data analysis.For example,knowing the vertical component of magnetic field provides a solution for the full magnetic field everywhere in the potential region.This is the familiar Neumann problem.In reality this ideal dataset is never available.In the past we were restricted to declination data only,then direction only,then total intensity only.There have also been large swathes of Earth's surface with no measurements at all(MSS-1 is restricted to latitudes below).These incomplete datasets throw up new questions for potential theory,questions that have some intriguing answers.When only declination is known uniqueness is provided by horizontal intensity measurements on a single line joining the dip-poles.When only directions are involved uniqueness is provided by a single intensity measurement,at least in principle.Paleomagnetic intensities can help.When only total intensity is known,as was largely the case in the early satellite era,uniqueness is provided by a precise location of the magnetic equator.Holes in the data distribution is a familiar problem in geophysical studies.All magnetic measurements sample,to a greater or lesser extent,the potential field everywhere.There is a trade-off between measurements close to the source,good for small targets and high resolution,and the broader sample of a distant measurement.The sampling of a measurement is given by the appropriate Green's function of the Laplacian,which determines both the resolution and scope of the measurement.For example,radial and horizontal measurements near the Earth's surface give a weighted average of the radial component over a patch of the core surface beneath the measurement site about in radius.The patch is smaller for shallower surfaces,for example from satellite to ground.Holes in the data distribution do not correspond to similar holes at the source surface;the price paid is in resolution of the source.I argue that,in the past,we have been too reluctant to take advantage of incomplete and apparently hopeless datasets. 展开更多
关键词 GEOMAGNETISM satellite observation Macao Science Satellites-1
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A two-stage scheduling algorithm based on pointer network with attention mechanism for micro-nano Earth observation satellite constellation
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作者 Hai LI Yuanhao LIU +5 位作者 Boyu DENG Yongjun LI Xin LI Yu LI Taijiang ZHANG Shanghong ZHAO 《Chinese Journal of Aeronautics》 2025年第8期433-448,共16页
Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growin... Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growing observation demands.The observation Scheduling Problem in the MEOS constellation(MEOSSP)is a challenging issue due to the large number of satellites and tasks,as well as complex observation constraints.To address the large-scale and complicated MEOSSP,we develop a Two-Stage Scheduling Algorithm based on the Pointer Network with Attention mechanism(TSSA-PNA).In TSSA-PNA,the MEOS observation scheduling is decomposed into a task allocation stage and a single-MEOS scheduling stage.In the task allocation stage,an adaptive task allocation algorithm with four problem-specific allocation operators is proposed to reallocate the unscheduled tasks to new MEOSs.Regarding the single-MEOS scheduling stage,we design a pointer network based on the encoder-decoder architecture to learn the optimal singleMEOS scheduling solution and introduce the attention mechanism into the encoder to improve the learning efficiency.The Pointer Network with Attention mechanism(PNA)can generate the single-MEOS scheduling solution quickly in an end-to-end manner.These two decomposed stages are performed iteratively to search for the solution with high profit.A greedy local search algorithm is developed to improve the profits further.The performance of the PNA and TSSA-PNA on singleMEOS and multi-MEOS scheduling problems are evaluated in the experiments.The experimental results demonstrate that PNA can obtain the approximate solution for the single-MEOS scheduling problem in a short time.Besides,the TSSA-PNA can achieve higher observation profits than the existing scheduling algorithms within the acceptable computational time for the large-scale MEOS scheduling problem. 展开更多
关键词 Micro-nano earth observation satellite observation scheduling Large-scale scheduling Two-stage optimization Pointer network Attention mechanism
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Minimum colonoscopy observation time for colonic diverticular bleeding: A new benchmark based on the 5% plateau time
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作者 Chikamasa Ichita Tadahiro Goto +2 位作者 Takashi Nishino Soichiro Nakaya Sayuri Shimizu 《World Journal of Gastroenterology》 2025年第40期123-134,共12页
BACKGROUND Colonic diverticular bleeding(CDB)is a leading cause of gastrointestinal blee-ding-related hospitalizations in Japan and is increasingly recognized as a signifi-cant burden in the United States.Identifying ... BACKGROUND Colonic diverticular bleeding(CDB)is a leading cause of gastrointestinal blee-ding-related hospitalizations in Japan and is increasingly recognized as a signifi-cant burden in the United States.Identifying the stigmata of a recent hemorrhage(SRH)during colonoscopy enables targeted hemostasis and reduces rebleeding.However,no benchmark exists for an appropriate observation duration,resulting in operator-dependent variation.Short observation periods may lead to missed SRH,whereas unnecessarily prolonged procedures,particularly in older patients,can increase patient burden and limit endoscopy unit availability.METHODS We retrospectively analyzed patients with acute hematochezia who underwent an initial colonoscopy between January 2017 and December 2024 at a Japanese tertiary hospital.The Observation time was measured from scope insertion to SRH detection(excluding therapeutic time)or withdrawal.The primary outcome,the“5%plateau time”,was defined as the point when the proportion of patients newly identified with SRH in each 5-minute interval consistently dropped below 5%.Computed tomography(CT)-based stratified analyses were performed by endoscopists who conducted≥10%of procedures.RESULTS Of the 1039 patients who underwent colonoscopy,845(mean age 77±11 years;64.5%male)were included.Nine board-certified endoscopists performed the procedures.SRH was detected in 286 patients(33.8%),with a median detection time of 19 minutes(interquartile range,12-28 minutes).The overall 5%plateau time was 40 minutes and varied according to the CT findings:40,35,and 30 minutes for no extravasation,right-sided extravasation,and left-sided extravasation,respectively.This time point corresponded to when 80%-90%of SRH cases were detected.De-spite variations in SRH detection rates and observation durations among endoscopists,the 5%plateau time was consistently approximately 40 minutes.CONCLUSION Although it varied according to the CT findings,the overall 5%plateau time was 40 minutes.This offers a practical benchmark for the minimum observation time without SRH detection. 展开更多
关键词 Diverticular hemorrhage Lower gastrointestinal bleeding Stigmata of recent hemorrhage observation time observation duration Withdraw time Bleeding source
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Ensemble-Based Adaptive Observations for Improving Sea Fog Prediction in Coastal Regions around the Bohai Sea:Case Study with Cold-Front Synoptic Pattern
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作者 Huiqin HU Chengqing RUAN Xiaolin YU 《Advances in Atmospheric Sciences》 2025年第4期794-815,共22页
This study explored the observation strategy and effectiveness of synoptic-scale adaptive observations for improving sea fog prediction in coastal regions around the Bohai Sea based on a poorly predicted fog event wit... This study explored the observation strategy and effectiveness of synoptic-scale adaptive observations for improving sea fog prediction in coastal regions around the Bohai Sea based on a poorly predicted fog event with cold-front synoptic pattern(CFSP).An ensemble Kalman filter data assimilation system for the Weather Research and Forecasting model was adopted with ensemble sensitivity analysis(ESA).By comparing observation impacts(estimated from a 40-member ensemble with ESA)among different meteorological observation variables and pressure levels,the temperature at 850 hPa and surface layer(850 hPa-and-surface temperature)was selected as the target observation type.Additionally,the area with large observation impacts for this observation type was predicted in the transition region of the surface low–high system.This area developed southward with the low and moved eastward with the low–high system,which could be explained by the main features of CFSP.Moreover,both experiments assimilating synthetic and real observations showed that assimilating 850 hPa-and-surface temperature observations generally yielded better fog coverage forecasts in areas with greater observation impacts than areas with smaller impacts.However,the effectiveness of adaptive observations was reduced when real observations rather than synthetic observations were assimilated,which is possibly due to factors such as observation and model errors.The main conclusions above were verified by another typical fog event with CFSP characteristics.Results of this study highlight the importance of improved initial conditions in the transition region of the low–high system for improving fog prediction and provide scientific guidance for implementing an observation network for fog forecasting over the Bohai Sea. 展开更多
关键词 sea fog forecasting synoptic-scale adaptive observations ESA method observations of temperature profile below 850 hPa cold-front synoptic pattern
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Aircraft Observations of Ice-Phase Microphysical Characteristics in Stratiform Clouds over the Qilian Mountains in Northwestern China
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作者 Yuyan LONG Tuanjie HOU +5 位作者 Baojun CHEN Shuangxi FU Rong ZHANG Shaofeng HUA Yi CHANG Boyue ZHANG 《Advances in Atmospheric Sciences》 2025年第9期1931-1946,共16页
The ice-phase microphysical characteristics of a stratiform cloud system over the Qilian Mountains in northwestern China on 15 September 2022 were analyzed via aircraft data.The stratiform cloud system developed under... The ice-phase microphysical characteristics of a stratiform cloud system over the Qilian Mountains in northwestern China on 15 September 2022 were analyzed via aircraft data.The stratiform cloud system developed under southwesterly flows at 500 hPa and was affected locally by topography.Synoptic features and aircraft observations revealed strengthened cloud development on the leeward slope.The ice particle habits and microphysical processes at heights of 6-8 km were investigated.The cloud system was characterized by extremely low supercooled liquid water content at temperatures between−4℃ and−17℃.The ice particle concentrations ranged predominantly from 10 to 30 L^(−1),corresponding to ice water content ranging from 0.01 to 0.05 g m^(−3).Active ice aggregation was observed at temperatures colder than−10°C.The windward side of the cloud system exhibited weaker development and two distinct cloud layers.Intense orographic uplift on the leeward slope enhanced ice particle aggregation.The clouds on the leeside presented lower ice particle concentrations but larger sizes than those on the windward side.The influence of aggregation on the ice particle size distribution was reflected in two main aspects.One aspect was the bimodal spectra at−16℃,with the first peak at 125μm and subpeak at 400-500μm;the other was the broadened size spectra at−13℃ due to significant aggregation of dendrites. 展开更多
关键词 aircraft observations Qilian Mountains ice concentrations AGGREGATION
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Radio astronomy observation on distributed deep space radar:A prototype experiment
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作者 Xue Chen Yuyang Ma +3 位作者 Xiaoyun Ma Junjie Huang Zehua Dong Zegang Ding 《Astronomical Techniques and Instruments》 2025年第5期275-279,共5页
Earth-based deep space radar studies celestial bodies by both transmitting and receiving radio waves,whereas radio telescopes only work passively.On the operational level,radar missions use only short observation time... Earth-based deep space radar studies celestial bodies by both transmitting and receiving radio waves,whereas radio telescopes only work passively.On the operational level,radar missions use only short observation times,which leaves a large portion of the time available for astronomical observations.However,the design principles used for radar and radio telescopes differ.Technical challenges are involved in making the instruments required to meet the requirements of these two applications simultaneously.In this study,we have attempted to tune a deep space radar system for use in radio astronomical applications and conducted a successful pulsar observation,thus demonstrating the feasibility of using radar systems,particularly distributed deep space radar,to perform astronomical research.Additionally,given the limited astronomical capacity available within the observed frequency range,this system has the potential to contribute to the long-term monitoring of specific radio sources.This work represents the first successful attempt to use an Earth-based deep space radar system to perform radio astronomy in China.We also discuss the challenges of tuning a built radar system for astronomical observation applications and propose recommendations for the design of future large-scale distributed deep space radar systems with innate astronomical capabilities. 展开更多
关键词 Radar telescopes Ground telescopes Radio observation
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Response characteristics of shear waves scattered by fractures with borehole observation system
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作者 Peng Liu Hua-Jun Fan +4 位作者 Meng-Sheng Zhang Zhen Li Jing-Wei Jiang Yuan Gao Ke-Wen Wang 《Petroleum Science》 2025年第5期1912-1928,共17页
Fractures play a crucial role in various fields such as hydrocarbon exploration,groundwater resources management,and earthquake research.The determination of fracture location and the estimation of parameters such as ... Fractures play a crucial role in various fields such as hydrocarbon exploration,groundwater resources management,and earthquake research.The determination of fracture location and the estimation of parameters such as fracture length and dip angle are the focus of geophysical work.In borehole observation system,the short distance between fractures and detectors leads to weak attenuation of elastic wave energy,and high-frequency source makes it easier to identify small-scale fractures.Compared to traditional monopole logging methods,dipole logging method has advantage of exciting pure shear waves sensitive to fractures,so its application is becoming increasingly widespread.However,since the reflected shear waves and scattered shear waves of fractures correspond to different fracture properties,how to distinguish and analyze these two kinds of waves is crucial for accurately characterizing the fracture parameters.To address this issue,numerical simulation of wave responses by a single fracture near a borehole in rock formation is performed,and the generation mechanism and characteristics of shear waves scattered by fractures are investigated.It is found that when the dip angle of the fracture surpasses a critical threshold,the S-wave will propagate to both endpoints of the fracture and generate scattered S-waves,resulting in two distinct scattered wave packets on the received waveform.When the polarization direction of the acoustic source is parallel to the strike of the fracture,the scattered SH-waves always have larger amplitude than the scattered SV-waves regardless of changing the fracture dip angle.Unlike SV-waves,the SH-waves scattered by the fracture do not have any mode conversion.Additionally,propagation of S-waves to a short length fracture can induce dipole mode vibration of the fracture within a wide frequency range.The phenomena of shear waves reflected and scattered by the fracture are further illustrated and verified by two field examples,thus showing the potential of scattered waves for fracture evaluation and characterization with borehole observation system. 展开更多
关键词 Numerical modeling Wave scattering Shear wave FRACTURES Borehole observation system
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Clinical Observation on the Management of Gestational Heart Failure and Delivery Outcomes
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作者 Hongjie Li Chenxi Li +8 位作者 Peng Sun Yuxing Zhai Li Wang Jie Cui Yanlin Mu Jiebing Han Wei Yuan Xinmei Hu Dapan Liang 《Journal of Clinical and Nursing Research》 2025年第1期231-235,共5页
Objective: This study focuses on the clinical observation of the impact of different treatment methods for gestational heart failure on delivery outcomes. Method: A total of 160 pregnant women with heart failure admit... Objective: This study focuses on the clinical observation of the impact of different treatment methods for gestational heart failure on delivery outcomes. Method: A total of 160 pregnant women with heart failure admitted to our hospital between October 2020 and October 2021 were selected as the study subjects. They were categorized based on delivery mode, delivery timing, heart failure control time, and cardiac function status. The delivery outcomes of the different groups were then compared. Result: In terms of delivery methods, the rate of neonatal asphyxia was higher following vaginal delivery than cesarean section. Regarding delivery timing, the neonatal mortality rate was lower for cesarean sections performed at 32-36 + 6 weeks compared to those conducted at 37-39 + 6 weeks. With respect to heart failure control time, the rates of neonatal asphyxia and pulmonary hyaline membrane disease were lower in the ≤ 48- hour group than in the > 48-hour group. From the perspective of cardiac function status, patients with cardiac function I- II exhibited relatively lower rates of neonatal asphyxia and perinatal mortality compared to those with cardiac function III-IV. The observed differences were statistically significant (P < 0.05). Conclusion: For patients with gestational heart failure, cesarean section is the recommended mode of delivery, with the optimal timing being between 32 and 36+6 weeks of pregnancy. During cesarean section, the timing of delivery should be carefully selected based on the mother’s cardiac function status. 展开更多
关键词 PREGNANCY Heart failure management Delivery method Clinical observation
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A Machine Learning-Based Observational Constraint Correction Method for Seasonal Precipitation Prediction
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作者 Bofei ZHANG Haipeng YU +5 位作者 Zeyong HU Ping YUE Zunye TANG Hongyu LUO Guantian WANG Shanling CHENG 《Advances in Atmospheric Sciences》 2025年第1期36-52,共17页
Seasonal precipitation has always been a key focus of climate prediction.As a dynamic-statistical combined method,the existing observational constraint correction establishes a regression relationship between the nume... Seasonal precipitation has always been a key focus of climate prediction.As a dynamic-statistical combined method,the existing observational constraint correction establishes a regression relationship between the numerical model outputs and historical observations,which can partly predict seasonal precipitation.However,solving a nonlinear problem through linear regression is significantly biased.This study implements a nonlinear optimization of an existing observational constrained correction model using a Light Gradient Boosting Machine(LightGBM)machine learning algorithm based on output from the Beijing National Climate Center Climate System Model(BCC-CSM)and station observations to improve the prediction of summer precipitation in China.The model was trained using a rolling approach,and LightGBM outperformed Linear Regression(LR),Extreme Gradient Boosting(XGBoost),and Categorical Boosting(CatBoost).Using parameter tuning to optimize the machine learning model and predict future summer precipitation using eight different predictors in BCC-CSM,the mean Anomaly Correlation Coefficient(ACC)score in the 2019–22 summer precipitation predictions was 0.17,and the mean Prediction Score(PS)reached 74.The PS score was improved by 7.87%and 6.63%compared with the BCC-CSM and the linear observational constraint approach,respectively.The observational constraint correction prediction strategy with LightGBM significantly and stably improved the prediction of summer precipitation in China compared to the previous linear observational constraint solution,providing a reference for flood control and drought relief during the flood season(summer)in China. 展开更多
关键词 observational constraint LightGBM seasonal prediction summer precipitation machine learning
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Direct observation of annealing-driven recrystallization behavior in magnesium alloy at low strain condition
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作者 Yuzhi Zhu Shuoxin Lv +3 位作者 Tianyi Li Yang Ren Zidong Wang Dewen Hou 《Journal of Magnesium and Alloys》 2025年第10期4985-4996,共12页
Grain-twin interactions are significant in texture modification under thermodynamic driving force.In this study,annealing-driven twinning/detwinning behavior,grain growth,and corresponding texture evolution in a pre-d... Grain-twin interactions are significant in texture modification under thermodynamic driving force.In this study,annealing-driven twinning/detwinning behavior,grain growth,and corresponding texture evolution in a pre-deformed AZ31 magnesium alloy were systematically tracked and investigated via in-situ heating synchrotron X-ray diffraction and quasi in-situ electron backscattered diffraction techniques.A twinning texture is generated in the pre-deformed sample due to the activation of{1012}tensile twinning.During annealing,dislocation annihilation occurs between 100 and 280℃,and recrystallization occurs above 280℃,manifesting as the initial residual matrix and twins being competitively swallowed by each other,forming a bimodal texture.The recrystallization process is completed by boundary movement,which depends on the energy difference across the boundary.In addition,it is found that the grain boundaries favor movement towards the side with higher stored energy,regardless of the boundary type or the boundary energy. 展开更多
关键词 Magnesium alloy TWIN Strain-induced boundary mobility TEXTURE In-situ observation
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Decoding of Surface Meteorological Observation Data Files and Application Research on Climatic Data
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作者 Hui LIANG Xianqiang SU Qingyun ZHU 《Meteorological and Environmental Research》 2025年第2期16-21,25,共7页
In this paper,Wuzhou City of Guangxi was taken as the research object.Through the design of a climatic data warehousing system,the decoding methods of surface meteorological data and their application in the managemen... In this paper,Wuzhou City of Guangxi was taken as the research object.Through the design of a climatic data warehousing system,the decoding methods of surface meteorological data and their application in the management of climatic data were explored.Based on the parsing technology of the monthly report of surface meteorological records(A-file),the design of Wuzhou climatic data warehousing system was realized,completing the precise extraction and database construction of observational elements such as regional temperature,wind direction,and weather phenomena.Based on this system,the meteorological data in 2024 were analyzed,and the probabilistic characteristics of dominant wind direction in Wuzhou(northeast wind accounting for the largest proportion),the spatiotemporal distribution patterns of extreme temperatures(annual extreme high temperature of 37.1℃in August and extreme low temperature of 1.9℃in January),and the general climatic overview of Wuzhou City(annual precipitation 3.2%higher than the standard value)were revealed.The research shows that climate change has a significant impact on agricultural production and economic development in Wuzhou City,and the construction of a reasonable climatic data database is of great significance for enhancing professional meteorological service capabilities in the context of climate change.This study not only provides a scientific basis for the economic development of Wuzhou region,but also offers reference ideas for other regions to cope with regional climate adaptation planning. 展开更多
关键词 Surface meteorological observation A-file decoding Climatic database Climate change
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Proactive personality and health literacy among patients with permanent colostomy:an observational study
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作者 Wen Li Hui Zheng +3 位作者 Hai-Bo Wang Ye Jiang Zhong-Zhen Yang Soh Kim Lam 《Frontiers of Nursing》 2025年第1期91-98,共8页
Objective:To investigate the distribution of health literacy(HL)levels and the association of HL with proactive personality in patients with permanent colostomy.Methods:A cross-sectional study was conducted to measure... Objective:To investigate the distribution of health literacy(HL)levels and the association of HL with proactive personality in patients with permanent colostomy.Methods:A cross-sectional study was conducted to measure proactive personality and HL using validated scales.A total of 172 patients with permanent colostomy were selected from January 2021 to May 2022 in Yantai City,China.Descriptive statistics,t-test,ANOVA,Pearson correlation analysis,and multiple linear regression analysis techniques were used.Results:The results obtained from the study showed that the HL status of the participants was moderate.The correlation between participants’total HL scores and proactive personality scores was 0.417(P-value<0.001).In addition,HL showed statistically significant differences according to education level,place of residence,profession,and average monthly household income.Conclusions:This study showed that patients with higher proactive personality scores had higher HL.The key stakeholders require several positive strategies to improve the HL of patients with permanent colostomy by cultivating their proactive personalities,and these important policies will help to improve patient health and quality of life. 展开更多
关键词 health literacy observational study permanent colostomy proactive personality surgical nursing
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Evaluation of the simulation performance of WRF-Solar for a summer month in China using ground observation network data
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作者 Xin Yue Xiao Tang +6 位作者 Bo Hu Keyi Chen Qizhong Wu Lei Kong Huangjian Wu Zifa Wang Jiang Zhu 《Atmospheric and Oceanic Science Letters》 2025年第4期7-14,共8页
Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels.However,the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation... Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels.However,the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation and prediction.Accurately simulating and predicting solar radiation and its variability are crucial for optimizing solar energy utilization.This study conducted simulation experiments using the WRF-Solar model from 25 June to 25 July 2022,to evaluate the accuracy and performance of the simulated solar radiation across China.The simulations covered the whole country with a grid spacing of 27 km and were compared with ground observation network data from the Chinese Ecosystem Research Network.The results indicated that WRF-Solar can accurately capture the spatiotemporal patterns of global horizontal irradiance over China,but there is still an overestimation of solar radiation,and the model underestimates the total cloud cover.The root-mean-square error ranged from 92.83 to 188.13 W m^(-2) and the mean bias(MB)ranged from 21.05 to 56.22 W m^(-2).The simulation showed the smallest MB at Lhasa on the Qinghai–Tibet Plateau,while the largest MB was observed in Southeast China.To enhance the accuracy of solar radiation simulation,the authors compared the Fast All-sky Radiation Model for Solar with the Rapid Radiative Transfer Model for General Circulation Models and found that the former provides better simulation. 展开更多
关键词 WRF-Solar Global horizontal irradiance Model evaluation Ground observation network China
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Clinical observation of white eye distribution in patients with hyperlipidemia:an artificial intelligence digital visual examination technique
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作者 SONG Tianli LI Haixia LIU Li'an 《Journal of Traditional Chinese Medicine》 2025年第5期1135-1143,共9页
OBJECTIVE:To explore the clinical observation of white eye distribution characteristics of hyperlipidemic patients based on artificial intelligence digital eye diagnosis technology.METHODS:One hundred and fifty subjec... OBJECTIVE:To explore the clinical observation of white eye distribution characteristics of hyperlipidemic patients based on artificial intelligence digital eye diagnosis technology.METHODS:One hundred and fifty subjects were examined in the outpatient and inpatient departments of Guang'anmen Hospital of the China Academy of Traditional Chinese Medicine from 01 February 2022 to 01 February 2023,including 80 cases in the hyperlipidemic patient(HLP)group and 70 cases in the normal lipid level patient(NC)group.The two groups were collected and extracted by the artificial intelligence visual diagnostic instrument and analyzed by the MyEyeD-10 white eye shadowless imaging health intelligence analysis system.Finally,SPSS 26.0(Version X;IBM Corp.,Armonk,NY,USA)was used for statistical processing.RESULTS:Significant differences were noted in the scores of"spot"and"foggy"features between the two groups.Between groups,the"spot"feature score of the white eye morphology in the HLP group(11.07±3.22)was higher than that in the NC group(7.50±4.11)(P<0.01).Moreover,the"foggy"feature score of the eye morphology in the HLP group(8.37±2.25)was higher than that in the NC group(P<0.01),higher than that of the NC group(5.72±1.21)(P<0.05).There were significant differences in the"A"(stomach),"B","O"(spleen),and"M"(liver)eye-contact region scores between the two groups,and the"B","O"(spleen)and"M"(liver)eye-contact region scores were significantly different.The scores of the white eye channel region in the HLP group were significantly higher than those in the control group,with the"A","B",and"O"regions(P<0.01),"M"region(P<0.01),"A","B","O",and"M"region(P<0.01)."M"zone(P<0.05).The scores of"dull red"and"yellow"features were significantly different,and the scores of"dull red"and"yellow"colors of the white eye choroid in the HLP group were significantly higher than those in the HLP group.The scores of"dull red"and"yellow"were significantly higher in the HLP group than in the NC group(P<0.01).CONCLUSION:The morphological features of the white eye ocular image,the white eye chakra's color,and the bulbar conjunctiva's vascular zoning are closely related to hyperlipidemia.Importantly,these provide a reference for the objectivity and precision of the identification of Chinese medicine by looking at the eyes. 展开更多
关键词 HYPERLIPIDEMIAS white-eyed eye image eye complex features artificial intelligence clinical observation
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Evaluating the accuracy of earth rotation parameters based on the BDS observations
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作者 Chenxiang Wang Pengfei Zhang +3 位作者 Tengxu Zhang Ziyu Shen Jizhang Sang Wenbin Shen 《Geodesy and Geodynamics》 2025年第1期87-98,共12页
The Bei Dou satellite system(BDS)has progressed with the full operationalization of the secondgeneration regional system(BDS-2)and the third-generation global system(BDS-3).This technology plays a crucial role in dete... The Bei Dou satellite system(BDS)has progressed with the full operationalization of the secondgeneration regional system(BDS-2)and the third-generation global system(BDS-3).This technology plays a crucial role in determining Earth Rotation Parameters(ERPs).In this study,we determine the ERPs based on the observations of BDS-2,BDS-3 and BDS-2+BDS-3,with the time spanning from August18,2022,to August 18,2023.The IERS EOP 20C04 series is used as a reference to evaluate the accuracy of the ERP estimates.We analyze the impact of different numbers of reference stations,polyhedron volumes,observation arc lengths,satellite types,and satellite systems on solving ERPs using BDS-2 and BDS-3 observation data provided by the International GNSS Service(IGS)stations.When selecting a specific satellite type,it is necessary to choose an appropriate observation arc length based on different numbers of reference stations while maximizing the volume of the formed polyhedron to achieve optimal efficiency and accuracy in parameter estimation.When both the number of reference stations and observation arc length are fixed,higher precision of the ERPs can be achieved using observations from MEO than MEO+IGSO and MEO+IGSO+GEO.Moreover,when considering only IGSO and MEO satellites as options for analysis purposes,BDS-3 provides higher accuracy compared to BDS-2.In summary,when using BDS for ERP estimation and MEO satellite observations with the same observation arc length,selecting stations from reference stations with larger polyhedral volumes can significantly improve the efficiency and accuracy of parameter estimation. 展开更多
关键词 Earth rotation parameters Polyhedron volume observation arc length BDS-2 BDS-3
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Modified Observation Error Inflation Scheme for All-Sky Infrared Radiance Assimilation Based on the Model–Observation Agreement
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作者 Bingying SHI Chun YANG Jinzhong MIN 《Advances in Atmospheric Sciences》 2025年第11期2333-2351,共19页
For all-sky infrared radiance assimilation,the heteroscedasticity and non-Gaussian behavior of observation-minusbackground(OMB)departures are two major difficulties.The Geer–Bauer observation error inflation(GBOEI)sc... For all-sky infrared radiance assimilation,the heteroscedasticity and non-Gaussian behavior of observation-minusbackground(OMB)departures are two major difficulties.The Geer–Bauer observation error inflation(GBOEI)scheme is a universal way to handle the issues.However,it fails to take into account the consistency between model and observation,resulting in unreasonably large observation errors where the simulations agree with the observations.Thus,this study modifies the GBOEI scheme to rationalize the observation errors in such areas.With Advanced Himawari Imager water vapor channel data,the test results show that the normalized OMB with the new observation error approach leads to more Gaussian form than the GBOEI method and constant observation errors.Hence,the assimilation experiments with the new scheme produce better brightness temperature analysis than other methods,and also improve temperature and humidity analysis.Furthermore,a real case experiment of Typhoon Lekima(2019)with the new observation error scheme exhibits more accuracy,especially in track prediction,and substantial error reductions in wind,temperature,and humidity forecasts are also obtained.Meanwhile,5-day 6-hour cycling experiments in the real case of Typhoon Lekima(2019)with the new observation error scheme confirm that the new method does not introduce extra imbalance compared to the experiment with constant observation errors;plus,more accurate typhoon forecasts can also be obtained in both the analysis and forecast,especially in track prediction. 展开更多
关键词 all-sky infrared radiance observation error satellite data assimilation landfalling typhoon
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