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Uncertainty-Aware Physical Simulation of Neural Radiance Fields for Fluids
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作者 Haojie Lian Jiaqi Wang +4 位作者 Leilei Chen Shengze Li Ruochen Cao Qingyuan Hu Peiyun Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期1143-1163,共21页
This paper presents a novel framework aimed at quantifying uncertainties associated with the 3D reconstruction of smoke from2Dimages.This approach reconstructs color and density fields from 2D images using Neural Radi... This paper presents a novel framework aimed at quantifying uncertainties associated with the 3D reconstruction of smoke from2Dimages.This approach reconstructs color and density fields from 2D images using Neural Radiance Field(NeRF)and improves image quality using frequency regularization.The NeRF model is obtained via joint training ofmultiple artificial neural networks,whereby the expectation and standard deviation of density fields and RGB values can be evaluated for each pixel.In addition,customized physics-informed neural network(PINN)with residual blocks and two-layer activation functions are utilized to input the density fields of the NeRF into Navier-Stokes equations and convection-diffusion equations to reconstruct the velocity field.The velocity uncertainties are also evaluated through ensemble learning.The effectiveness of the proposed algorithm is demonstrated through numerical examples.The presentmethod is an important step towards downstream tasks such as reliability analysis and robust optimization in engineering design. 展开更多
关键词 Uncertainty quantification neural radiance field physics-informed neural network frequency regularization twolayer activation function ensemble learning
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A Study on the Educational Significance Guidance Plan Value of the Jumong Myth Using STEAM
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作者 Lee Eun-min 《Cultural and Religious Studies》 2024年第6期338-355,共18页
Jumong is a legendary figure in Korean mythology.He is depicted as a genius archer,a brilliant mind with horses,a god who rules the rivers and the sky.Jumong is a mythical character who is believed to be of divine des... Jumong is a legendary figure in Korean mythology.He is depicted as a genius archer,a brilliant mind with horses,a god who rules the rivers and the sky.Jumong is a mythical character who is believed to be of divine descent and to possess superhuman abilities that humans cannot match.The myth of Jumong is a very competitive content that can compete on a global scale.However,in order for it to be successful,it is necessary to be able to reinterpret our mythology to suit the times and reproduce it culturally.To this end,the realistic globalization of Korean classical literature should commence with the genre of Korean mythology.This paper presents the educational significance of the Jumong myth as a teaching-learning model,via STEAM(science,technology,engineering,arts,and mathematics),on the theme of Korean mythology.As we enter the era of artificial intelligence(AI)through the 4th Industrial Revolution,the most appropriate teaching and learning method,the convergence class,will provide an opportunity for students living in modern times to discover the cultural archetypes that allow them to recognise themselves as individuals and us as a collective,and to find the roots of the myth to positively renew their identity.Furthermore,it is my hope that they will rediscover and appreciate the representative work of Korean mythology,Gojomong,the eponymous story of Goguryeo. 展开更多
关键词 Jumong STEAM educational significance personal and reflective assessments organic complexes evaluate a collaborative activity(rubric)
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Implementation and Insights on Science Inquiry Activities in Kindergartens Under the Concept of STEM Education
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作者 Qingqing Cheng 《Journal of Contemporary Educational Research》 2024年第7期182-186,共5页
The STEM education philosophy spans across disciplines such as science,technology,engineering,and mathematics.In the context of thematic activities in kindergartens,teachers can utilize the STEM education philosophy t... The STEM education philosophy spans across disciplines such as science,technology,engineering,and mathematics.In the context of thematic activities in kindergartens,teachers can utilize the STEM education philosophy to cultivate children’s innovative thinking qualities and practical operation skills,helping them develop a scientific inquiry spirit and skills.This paper takes the development of science inquiry activities in kindergartens as a path,exploring the significance and implementation paths of applying the STEM education philosophy in such activities. 展开更多
关键词 STEM education Science inquiry Thematic activities
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Side Effects of Gamifying Environmental Education Activities in Chinese Kindergartens 被引量:1
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作者 Huanhuan Zhang Wanping Bao +1 位作者 Xiaoshu Xu Yunfeng Zhang 《教育技术与创新》 2023年第4期71-86,共16页
Environmental education is an effective approach to addressing environmental issues,and incorporating environmental education into kindergarten through gamified activities aligns with the concept of gamifying teaching... Environmental education is an effective approach to addressing environmental issues,and incorporating environmental education into kindergarten through gamified activities aligns with the concept of gamifying teaching and provides the optimal pathway for implementing environmental education.The purpose of this study is to investigate the specific processes involved in determining the objectives,themes,and content of gamified environmental education activities,as well as the organization,implementation,and evaluation of these activities in kindergarten settings.Five classes from Class G in Xining City Kindergarten were selected as the observational subjects for this study.Interviews were conducted with the teaching staff and the head of the kindergarten.The data obtained from observations and interviews served as the primary data for this research.The results indicate that the activity objectives formulated by teachers lack scientific basis and operability,with limited incorporation of gaming elements.The activity themes and content are narrow in scope and primarily determined by teachers and kindergarten administrators.The organization and implementation of activities often neglect the playful experiences of children,and activity evaluation is not given sufficient attention. 展开更多
关键词 KinDERGARTEN Environmental education activities GAMIFICATION Side effect China
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Effects of physical activity by the teach-back educational method on the physical ability and quality of life in hemodialysis patients:a clinical trial
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作者 Pegah Sharifian Arash Khalili Morteza Shamsizadeh 《Frontiers of Nursing》 2023年第2期223-231,共9页
Objective:To determine the effect of physical activity by using the teach-back educational method on hemodialysis patients’quality of life(QOL)and physical ability.Methods:This is a single-blind clinical trial study ... Objective:To determine the effect of physical activity by using the teach-back educational method on hemodialysis patients’quality of life(QOL)and physical ability.Methods:This is a single-blind clinical trial study involving a control group.A total of 90 patients who admitted to the dialysis centers of Beheshti and Besat hospitals in Hamadan were selected using a convenience sampling method and were randomly assigned to intervention(n=45)and control(n=45)groups.Data were collected using a demographic information checklist,a kidney disease QOL questionnaire,and a 6-minute-walk distance(6MWD)checklist.The patients’QOL questionnaire was completed,and the 6MWD was recorded before and at the end of the 2nd,4th,6th,8th,and 12th weeks of the intervention.In the intervention group,the patients were taught to perform physical activities with Pilates stretches in different resistances using the teach-back educational method during dialysis sessions for 12 weeks.Data were analyzed by using the independent t-test and chi-square test using SPSS-22 software.Results:Before the intervention,no differences were observed between the experimental and control groups in terms of demographic characteristics,QOL,and physical ability(P>0.05).The physical ability and QOL levels of patients exercising in the test group were higher than those in the control group after the intervention(P<0.05).Based on the results,the 2 groups significantly differed with regard to the scores of various dimensions of QOL and physical ability after the intervention(P<0.05).Conclusions:Physical activity by using the teach-back method can effectively increase physical ability and improve QOL of hemodialysis patients.Therefore,the recommendations and inclusion of exercise in the dialysis care plan can effectively promote patients’health. 展开更多
关键词 hemodialysis patients physical ability physical activity quality of life teach-back education
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Prenatal Playful-Educational Activities, Psycho-Emotional Well-Being of Pregnant Women and Perinatal Outcomes: A Pilot Study 被引量:1
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作者 Jaime Salvador-Moysén Blanca Edith Cobián-López +2 位作者 Yolanda Martínez-López Edgar Felipe Lares-Bayona María del Socorro Páez-Güereca 《Open Journal of Obstetrics and Gynecology》 2021年第2期102-116,共15页
<strong>Objective:</strong><span style="font-family:""><span style="font-family:Verdana;"> To present the results of a pilot study that evaluated the psycho-emotional w... <strong>Objective:</strong><span style="font-family:""><span style="font-family:Verdana;"> To present the results of a pilot study that evaluated the psycho-emotional well-being, and the perinatal results of a group of 44 women who attended a prenatal program that incorporates playful and educational activities, in a Child Development Center in Durango. Mexico. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> A group of 44 women with informed consent participated for 28 weeks in the prenatal program. The condition of psycho-emotional well-being during the first and third trimesters and the perinatal results were analyzed with validated instruments. Physiological stress was also assessed with salivary cortisol in the same trimesters. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> More than 90% of the women evaluated their psycho-emotional condition as satisfactory and very satisfactory. The evaluation of anxiety in its Trait/State modalities placed the participants in the category of mild and moderate. Salivary cortisol showed values within a normal range. Perinatal results showed that 98% of deliveries were at term, 93% of newborns weighed more than 2500 grams, and 98% of newborns had an APGAR score of 9 at 5 minutes. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The results suggest that the incorporation of playful and educational actions to prenatal surveillance positively influenced the biopsychosocial condition of the pregnant woman and favorable perinatal outcomes.</span></span> 展开更多
关键词 PRENATAL CARE PRENATAL Education Playful activities MATERNAL HEALTH HEALTHY PREGNANCY Comprehensive HEALTH CARE
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Research on the Strategy of Integrating Red Culture into Patriotic Education Activities of Young People
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作者 Hongnv Zhao Long Wang Shiyu Liu 《Open Journal of Applied Sciences》 2023年第7期1178-1195,共18页
Young people are the flowers of the motherland, is the future of the motherland, youth teachers have great responsibilities. Integrate red culture into daily teaching activities, inherit and carry forward, enhance chi... Young people are the flowers of the motherland, is the future of the motherland, youth teachers have great responsibilities. Integrate red culture into daily teaching activities, inherit and carry forward, enhance children’s values, cultivate children’s excellent qualities such as patriotism and selfless dedication, improve children’s comprehensive quality, and let children grow up healthily. Taking red culture as the starting point, this paper discusses the strategy of integrating red cultural resources into patriotic education activities of teenagers, points out the existing problems in the current integration of red culture into patriotic education activities of teenagers and finds out the reasons;clarify the relevant concepts of red culture and patriotic education activities for young people;from the three aspects of integrating curriculum resources to enhance the significance of red culture education, creating a red environment to create a red education atmosphere, and digging deep into red cultural resources, this paper discusses the strategy of integrating red culture into patriotic education activities for young people, aiming to promote the organic combination of patriotic education activities and red culture for young people, and increase national and cultural self-confidence. 展开更多
关键词 Red Culture Youth Patriotic Education activities STRATEGY
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A Statistical Study of Magnetic Flux Emergence in Solar Active Regions Prior to Strongest Flares
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作者 Alexander S.Kutsenko Valentina I.Abramenko Andrei A.Plotnikov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第4期147-160,共14页
Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24,we explored 100 active regions(ARs)that produced M5.0 or stronger flares.We focus on the presence/absence of the emergence of ma... Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24,we explored 100 active regions(ARs)that produced M5.0 or stronger flares.We focus on the presence/absence of the emergence of magnetic flux in these ARs 2-3 days before the strong flare onset.We found that 29 ARs in the sample emerged monotonically amidst quiet-Sun.A major emergence of a new magnetic flux within a pre-existing AR yielding the formation of a complex flare-productive configuration was observed in another 24 cases.For 30 ARs,an insignificant(in terms of the total magnetic flux of pre-existing AR)emergence of a new magnetic flux within the pre-existing magnetic configuration was observed;for some of them the emergence resulted in a formation of a configuration with a small δ-sunspot;11 out of 100 ARs exhibited no signatures of magnetic flux emergence during the entire interval of observation.In six cases the emergence was in progress when the AR appeared on the Eastern limb,so that the classification and timing of emergence were not possible.We conclude that the recent flux emergence is not a necessary and/or sufficient condition for strong flaring of an AR.The flux emergence rate of flare-productive ARs analyzed here was compared with that of flare-quiet ARs analyzed in our previous studies.We revealed that the flare-productive ARs tend to display faster emergence than the flare-quiet ones do. 展开更多
关键词 Sun:activity Sun:flares Sun:magnetic fields
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Screening and field application of microbial-flooding activator systems
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作者 Xiutian Yao Lipeng Gai +6 位作者 Yun Feng Runlin Zhao Yang Gao Yucui Zhang Chuanzhi Cui Jun Ma Zhongwei Wu 《Energy Geoscience》 EI 2024年第2期14-20,共7页
This study aims to further enhance the oil recovery of reservoirs in the Zhong-2 Block of the Gudao Oilfield by identifying the most effective microbial-flooding activator systems and applying them in the field.We beg... This study aims to further enhance the oil recovery of reservoirs in the Zhong-2 Block of the Gudao Oilfield by identifying the most effective microbial-flooding activator systems and applying them in the field.We began by analyzing the structure of the reservoirs'endogenous microbial communities to understand the potential impact of microbial flooding.This was followed by determining commonly used activator systems based on their abilities to stimulate oil-displacement functional bacteria.Through laboratory experiments on oil displacement efficiency and sweep characteristics,we determined the optimal activator injection method(injection ratio)and the requisite bacterial concentration for maximal microbial-flooding efficacy.Finally,we selected the optimal activator systems and applied them to field tests.Our findings suggest the target block is highly receptive to microbial-flooding.In terms of performance,the activator systems ranked as No.3>No.4>No.1>No.2.Interestingly,a deep activator system,when compared to the top-performing No.3 system,exhibited a higher bacterial concentration peak and longer peaking duration.Optimal oil displacement effects were observed at a 1:4 vol ratio between the No.3 activator and deep activator systems,with bacterial concentrations of up to 106 cells/mL or above.Field tests with the selected activator systems,following a specific injection protocol,demonstrated a notable increase in oil production and a reduction in water cut. 展开更多
关键词 Zhong-2 Block of Gudao Oilfield Microbial flooding Laboratory experiment Screening of activator system Field application
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A Confined Two-peaked Solar Flare Observed by EAST and SDO
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作者 Liang Zhang Ruisheng Zheng +6 位作者 Zhike Xue Changhui Rao Qing Lin Zhimao Du Jiawen Yao Libo Zhong Yao Chen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第4期71-83,共13页
The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature th... The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature that is deserved much more attentions.Here,we reported a confined two-peaked solar flare and analyzed the associated eruptions using high-quality observations from Educational Adaptive-optics Solar Telescope and Solar Dynamics Observatory.Before the flare,a magnetic flux rope(MFR)formed through partially tether-cutting reconnection between two sheared arches.The flare occurred after the MFR eruption that was confined by the overlying strong field.Interestingly,a small underlying filament immediately erupted,which was possibly destabilized by the flare ribbon.The successive eruptions were confirmed by the analysis of the emission measure and the reconnection fluxes.Therefore,we suggest that the two peaks of the confined solar flare are corresponding to two episodes of magnetic reconnection during the successive eruptions of the MFR and the underlying filament. 展开更多
关键词 Sun:activity Sun:corona Sun:flares Sun:magnetic fields Sun:filaments prominences Online material:animations
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Self-sustained firing activities of the cortical network with plastic rules in weak AC electrical fields
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作者 秦迎梅 王江 +3 位作者 门聪 赵佳 魏熙乐 邓斌 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第7期604-610,共7页
Both external and endogenous electrical fields widely exist in the environment of cortical neurons. The effects of a weak alternating current (AC) field on a neural network model with synaptic plasticity are studied... Both external and endogenous electrical fields widely exist in the environment of cortical neurons. The effects of a weak alternating current (AC) field on a neural network model with synaptic plasticity are studied. It is found that self-sustained rhythmic firing patterns, which are closely correlated with the cognitive functions, are significantly modified due to the self-organizing of the network in the weak AC field. The activities of the neural networks are affected by the synaptic connection strength, the exterrtal stimuli, and so on. In the presence of learning rules, the synaptic connections can be modulated by the external stimuli, which will further enhance the sensitivity of the network to the external signal. The properties of the external AC stimuli can serve as control parameters in modulating the evolution of the neural network. 展开更多
关键词 spike-timing-dependent plasticity (STDP) weak electrical field rhythmic activity
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ENSO Index Variations and Links with Solar and Volcanic Activity
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作者 Valentina V. Zharkova Irina Vasilieva 《Natural Science》 2024年第4期25-44,共20页
In this paper, we investigated the Oceanic Niño Index (ONI), for simplicity called in this paper an El Nino Southern Oscillation (ENSO) index in 1950-2023 by applying the wavelet spectral transform and the IBM SP... In this paper, we investigated the Oceanic Niño Index (ONI), for simplicity called in this paper an El Nino Southern Oscillation (ENSO) index in 1950-2023 by applying the wavelet spectral transform and the IBM SPSS correlations analysis. ONI follows the three months’ current measurements of the average temperature of the sea surface in the East-Central tropical part of the Pacific Ocean nearby the international line of the date change over the average sea surface temperature over the past 30 years. The ENSO index is found to have a strong (>87%) correlation with the Global Land-Ocean Temperature (GLOT). The scatter plots of the ENSO-GLOT correlation with the linear and cubic fits have shown that the ENSO index is better fit by the cubic polynomial increasing proportionally to a cubic power of the GLOT variations. The wavelet analysis allowed us to detect the two key periods in the ENSO (ONI) index: 4 - 5 years and 12 years. The smaller period of 4.5 years can be linked to the motion of tectonic plates while the larger period of 12 years is shown to have a noticeable correlation of 25% with frequencies of the underwater (submarine) volcanic eruptions in the areas with ENSO occurrences. Not withholding any local terrestrial factors considered to contribute to the ENSO occurrences, we investigated the possibility of the volcanic eruptions causing ENSO to be also induced by the tidal forces of Jupiter and Sun showing the correlation of the underwater volcanic eruption frequency with the Jupiter-Earth distances to be 12% and with the Sun-Earth distances, induced by the solar inertial motion, in January, when the Earth is turned to the Sun with the southern hemisphere where the ENSO occurs, to become 15%. Hence, the underwater volcanic eruptions induced by tidal forces of Jupiter and Sun can be the essential additional factors imposing this 12 year period of the ENSO (ONI) index variations. 展开更多
关键词 Sun: Magnetic Field Sun: Solar Activity Sun: inertial Motion Earth: Temperature Earth: Sea Level Earth: Ice Area
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Making the case for the evolving role of social media in health professions education and a literature review on the application of some in ophthalmology
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作者 Helena Prior Filipe Mila Kostic +1 位作者 Mildred Lopez Karl Golnik 《Annals of Eye Science》 2024年第2期1-11,共11页
Background and Objective:Social media(SoMe)has emerged as a tool in health professions education(HPE),particularly amidst the challenges posed by the coronavirus disease 2019(COVID-19)pandemic.Despite the academia’s ... Background and Objective:Social media(SoMe)has emerged as a tool in health professions education(HPE),particularly amidst the challenges posed by the coronavirus disease 2019(COVID-19)pandemic.Despite the academia’s initial skepticism SoMe has been gaining traction in supporting learning communities,and offering opportunities for innovation in HPE.Our study aims to explore the integration of SoMe in HPE.Four key components were outlined as necessary for a successful integration,and include designing learning experiences,defining educator roles,selecting appropriate platforms,and establishing educational objectives.Methods:This article stemmed from the online Teaching Skills Series module on SoMe in education from the Ophthalmology Foundation,and drew upon evidence supporting learning theories relevant to SoMe integration and models of education.Additionally,we conducted a literature review considering Englishlanguage articles on the application of SoMe in ophthalmology from PubMed over the past decade.Key Content and Findings:Early adopters of SoMe platforms in HPE have leveraged these tools to enhance learning experiences through interaction,dialogue,content sharing,and active learning strategies.By integrating SoMe into educational programs,both online and in-person,educators can overcome time and geographical constraints,fostering more diverse and inclusive learning communities.Careful consideration is,however,necessary to address potential limitations within HPE.Conclusions:This article lays groundwork for expanding SoMe integration in HPE design,emphasizing the supportive scaffold of various learning theories,and the need of furthering robust research on examining its advantages over traditional educational formats.Our literature review underscores an ongoing multifaceted,random application of SoMe platforms in ophthalmology education.We advocate for an effective incorporation of SoMe in HPE education,with the need to comply with good educational practice. 展开更多
关键词 Social media(SoMe) health professions education(HPE) active learning social learning technology enhanced learning
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Determination of the Topology Skeleton of Magnetic Fields in a Solar Active Region 被引量:4
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作者 Hui Zhao Jing-Xiu Wang +2 位作者 Jun Zhang Chi-Jie Xiao Hai-Min Wang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2008年第2期133-145,共13页
Magnetic topology has been a key to the understanding of magnetic energy release mechanism. Based on observed vector magnetograms, we have determined the threedimensional (3D) topology skeleton of the magnetic field... Magnetic topology has been a key to the understanding of magnetic energy release mechanism. Based on observed vector magnetograms, we have determined the threedimensional (3D) topology skeleton of the magnetic fields in the active region NOAA 10720. The skeleton consists of six 3D magnetic nulls and a network of corresponding spines, fans, and null-null lines. For the first time, we have identified a spiral magnetic null in Sun's corona. The magnetic lines of force twisted around the spine of the null, forming a 'magnetic wreath' with excess of free magnetic energy and resembling observed brightening structures at extraultraviolet (EUV) wavebands. We found clear evidence of topology eruptions which are referred to as catastrophic changes of topology skeleton associated with a coronal mass ejection (CME) and an explosive X-ray flare. These results shed new lights on the structural complexity and its role in explosive magnetic activity. The concept of flux rope has been widely used in modelling explosive magnetic activity, although their observational identity is rather obscure or, at least, lacking of necessary details up to date. We suggest that the magnetic wreath associated with the 3D spiral null is likely an important class of the physical entity of flux ropes. 展开更多
关键词 Sun: magnetic fields -- Sun: solar corona -- Sun: activity
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The Relationship between Magnetic Gradient and Magnetic Shear in Five Super Active Regions Producing Great Flares 被引量:2
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作者 Hai-Min Wang Hui Song +5 位作者 Ju Jing Vasyl Yurchyshyn Yuan-Yong Deng Hong-Qi Zhang David Falconer Jing Li 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第4期477-488,共12页
We study the magnetic structure of five well-known active regions that produced great flares (X5 or larger). The six flares under investigation are the X12 flare on 1991 June 9 in AR 6659, the X5.7 flare on 2000 Jul... We study the magnetic structure of five well-known active regions that produced great flares (X5 or larger). The six flares under investigation are the X12 flare on 1991 June 9 in AR 6659, the X5.7 flare on 2000 July 14 in AR 9077, the X5.6 flare on 2001 April 6 in AR 9415, the X5.3 flare on 2001 August 25 in AR 9591, the X17 flare on 2003 October 28 and the X10 flare on 2003 October 29, both in AR 10486. The last five events had corresponding LASCO observations and were all associated with Halo CMEs. We analyzed vector magnetograms from Big Bear Solar Observatory, Huairou Solar Observing Station, Marshall Space Flight Center and Mees Solar Observatory. In particular, we studied the magnetic gradient derived from line-of-sight magnetograms and magnetic shear derived from vector magnetograms, and found an apparent correlation between these two parameters at a level of about 90%. We found that the magnetic gradient could be a better proxy than the shear for predicting where a major flare might occur: all six flares occurred in neutral lines with maximum gradient. The mean gradient of the flaring neutral lines ranges from 0.14 to 0.50 G km^-1, 2.3 to 8 times the average value for all the neutral lines in the active regions. If we use magnetic shear as the proxy, the flaring neutral line in at least one, possibly two, of the six events would be mis-identified. 展开更多
关键词 Sun: activity -- Sun: flares -- Sun: magnetic fields -- Sun: coronal mass ejections (CMEs)
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On the Relation Between Coronal Green Line Brightness and Magnetic Fields Intensity 被引量:2
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作者 Xue-Fei Zhang Yu Liu +4 位作者 Ming-Yu Zhao Teng-Fei Song Jing-Xing Wang Xiao-Bo Li Zi-Han Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第7期128-138,共11页
Two-dimensional(2 D) solar coronal magnetogram is difficult to be measured directly until now.From the previous knowledge,a general relation has been noticed that the brighter green-line brightness for corona,the high... Two-dimensional(2 D) solar coronal magnetogram is difficult to be measured directly until now.From the previous knowledge,a general relation has been noticed that the brighter green-line brightness for corona,the higher coronal magnetic field intensity may correspond to.To try to further reveal the relationship between coronal green line brightness and magnetic field intensity,we use the 2 D coronal images observed by Yunnan Observatories Greenline Imaging System(YOGIS) of the 10 cm Lijiang coronagraph and the coronal magnetic field maps calculated from the current-free extrapolations with the photospheric magnetograms taken by Helioseismic and Magnetic Imager(HMI) on board the Solar Dynamics Observatory(SDO) spacecraft.In our analysis,we identified the coronal loop structures and construct two-dimensional maps of the corresponding magnetic field intensity in the plane of the sky(POS) above the limb.We derive the correlation coefficients between the coronal brightness and the magnetic field intensity for different heights of coronal layers.We further use a linear combination of a Gaussian and a quadratic profile to fit the correlation coefficients distribution,finding a largest correlation coefficient of 0.82 near 1.1 R(solar radii) where is almost the top of the closed loop system.For the small closed loop system identified,the correlation coefficient distributions crossing and covering the loop are calculated.We also investigate the correlation with extended heliocentric latitude zones and long period of one whole Carrington Rotation,finding again that the maximum correlation coefficient occurs at the same height.It is the first time for us to find that the correlation coefficients are high(all are larger than 0.8) at the loop-tops and showing poor correlation coefficients with some fluctuations near the feet of the coronal loops.Our findings indicate that,for the heating of the low-latitude closed loops,both DC(dissipation of currents) and AC(dissipation of Alfvén and magnetosonic waves) mechanisms should act simultaneously on the whole closed loop system while the DC mechanisms dominate in the loop-top regions.Therefore,in the distributions of the correlation coefficients with different heights of coronal layers,for both large-and small-scale latitude ranges,the coefficients can reach their maximum values at the same coronal height of 1.1 R,which may indicate the particular importance of the height of closed loops for studying the coupling of the local emission mechanism and the coronal magnetic fields,which maybe helpful for studying the origin of the low-speed solar wind. 展开更多
关键词 Sun:magnetic fields Sun:corona Stars:coronae Sun:activity Sun:atmosphere Sun:coronal mass ejections(CMEs) Sun:fundamental parameters Sun:heliosphere Sun:UV radiation
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Simulation Researches on Influence of Different Axial Magnetic Fields on Anode Activity in High-current Vacuum Arcs 被引量:8
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作者 WANG Lijun JIA Shenli CHEN Bin ZHOU Xin YANG Dingge SHI Zongqian 《中国电机工程学报》 EI CSCD 北大核心 2012年第13期I0018-I0018,201,共1页
纵向磁场对阳极活动的控制效果对于大电流真空电弧成功开断十分关键。采用建模仿真的方法,分析不同纵向磁场强度对阳极活动的影响。基于大电流真空电弧模型,仿真得到不同纵向磁场强度下输入阳极的能流密度分布,并以此作为阳极活动模... 纵向磁场对阳极活动的控制效果对于大电流真空电弧成功开断十分关键。采用建模仿真的方法,分析不同纵向磁场强度对阳极活动的影响。基于大电流真空电弧模型,仿真得到不同纵向磁场强度下输入阳极的能流密度分布,并以此作为阳极活动模型的边界条件,得到不同磁场强度下的阳极熔化、蒸发情况。仿真结果表明:对于工频电流(50Hz)电弧,阳极温度的最大值出现7ms时刻附近;随着纵向磁场的增大,阳极表面温度、饱和蒸汽压、阳极蒸汽流量都相应减小;随着纵向磁场的增大,熔化半径增大,但是熔化深度减小,改善了阳极的烧蚀情况。 展开更多
关键词 大电流真空电弧 阳极活性 轴向磁场 仿真方法 磁场控制 高电流
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Flipped classroom approach to global outreach:cross-cultural teaching of horizontal strabismus to Chinese ophthalmology residents 被引量:2
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作者 Randy Lu Ryan E Dodge Ⅲ +5 位作者 Jocelyn Lam Laura Enyedi Tammy Yanovitch Nandini Gandhi Leona Ding Michelle T Cabrera 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第2期280-285,共6页
AIM:To evaluate the flipped classroom model for teaching horizontal strabismus didactics in an ophthalmology residency program in China as part of a visiting professorship from the United States.METHODS:Residents from... AIM:To evaluate the flipped classroom model for teaching horizontal strabismus didactics in an ophthalmology residency program in China as part of a visiting professorship from the United States.METHODS:Residents from an ophthalmology residency program in China were invited to participate in flipped classroom sessions taught by an experienced American ophthalmology faculty in 2018.Residents were instructed to watch a pre-class video lecture prior to the in-class-casebased activity.Content tests(5 Ophthalmic Knowledge Assessment Program style questions)and surveys were administered before and after the classroom sessions(100%response rate).These results were compared to that of an American cohort who were taught the same content.RESULTS:The Chinese cohort of 12 residents preferred the flipped classroom to the traditional classroom at higher rates than the American cohort of 40 residents(92%vs 55%,P=0.04)and felt that all ophthalmology topics would be appropriate for the flipped classroom teaching style(P-values between 0.008 and<0.001).In both Chinese and American cohorts,we found that the exotropia curriculum saw a small but significant improvement in performance following the flipped classroom session(P=0.025 for Chinese residents;P=0.001 for US residents),whereas scores in both groups for the esotropia course did not significantly improve.CONCLUSION:This is the first study to evaluate the flipped classroom model implemented by a visiting ophthalmology professor in a global outreach setting.The flipped classroom sessions are viewed favorably by the Chinese residents relative to the US cohort with a modest impact on knowledge.Decreased in-person interpreter requirement and increased student engagement make this model valuable in cross-cultural visiting professorship settings.Finally,the flipped classroom may lend itself well to a virtual format to prevent the transmission of COVID-19,although such a format requires further study. 展开更多
关键词 flipped classroom international ophthalmology residency graduate medical education China active learning medical education OPHTHALMOLOGY
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Spatial Distribution and Environmental Determinants of Denitrification Enzyme Activity in Reed-Dominated Raised Fields 被引量:2
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作者 LAN Yan CUI Baoshan +3 位作者 HAN Zhen LI Xia LI Fengju ZHANG Yongtao 《Chinese Geographical Science》 SCIE CSCD 2015年第4期438-450,共13页
Denitrification is an important process of nitrogen removal in lake ecosystems.However,the importance of denitrification across the entire soil-depth gradients including subsurface layers remains poorly understood.Thi... Denitrification is an important process of nitrogen removal in lake ecosystems.However,the importance of denitrification across the entire soil-depth gradients including subsurface layers remains poorly understood.This study aims to determine the spatial pattern of soil denitrification enzyme activity(DEA) and its environmental determinants across the entire soil depth gradients in the raised fields in Baiyang Lake,North China.In two different zones of the raised fields(i.e.,water boundary vs.main body of the raised fields),the soil samples from 1.0 m to 1.1 m depth were collected,and the DEA and following environmental determinants were quantified:soil moisture,p H,total nitrogen(TN),ammonia nitrogen(NH4+-N),nitrate nitrogen(NO3–-N),total organic carbon(TOC),and rhizome biomass of Phragmites australis.The results showed that the soil DEA and environmental factors had a striking zonal distribution across the entire soil depth gradients.The soil DEA reached two peak values in the upper and middle soil layers,indicating that denitrification are important in both topsoil and subsurface of the raised fields.The correlation analysis showed that the DEA is negatively correlated with the soil depth(p < 0.05).However,this phenomenon did not occur in the distance to the water edge,except in the upper layers(from 0.2 m to 0.7 m) of the boundary zone of the raised fields.In the main body of the raised fields,the DEA level remained high;however,it showed no significant relationship with the distance to the water edge.The linear regression analysis showed significant positive correlation of the DEA with the soil TN,NO3–-N,NH4+-N,and TOC;whereas it showed negative correlation with soil p H.No significant correlations with soil moisture and temperature were observed.A positive correlation was also found between the DEA and rhizome biomass of P.australis. 展开更多
关键词 反硝化脱氮 环境因素 酶活性 空间分布 芦苇 土壤深度 土壤水分 湖泊生态系统
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Soil Phosphorus Release to the Water Bodies in the Upland Fields of Yellow Soil Areas and Impacting Factor
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作者 LIU Fang LUO Hai-bo +3 位作者 SU Yin-ge LIU Yuan-sheng HE Teng-bin LONG Jian 《Agricultural Sciences in China》 CAS CSCD 2005年第12期916-923,共8页
Soil phosphorus release to the water bodies in the upland fields of yellow soil areas and impacting factor was studied in Guizhou province. The results showed that the content of dissolved active P of surface runoff f... Soil phosphorus release to the water bodies in the upland fields of yellow soil areas and impacting factor was studied in Guizhou province. The results showed that the content of dissolved active P of surface runoff from various upland fields of yellow-soil were significantly different, which the concentrations of dissolved active P of runoff correlated with the contents of available-P, amorphous oxides of A1, and organic matter in the soils. The amount of soil phosphorus release to the water bodies affected by the level of applying P fertilizer and the process of corn growth, which with fertilizing from 150 to 900 kg P205 ha^-1 in the soil with high P level, the average contents of dissolved active P in the permeability-water of the soil increased from 0.020 mg L^-1 to 0.137 mg L^-1. The amount of soil phosphorus release to the water bodies also affected by environmental factor, which the amount of soil phosphorus release significantly increased under the conditions that temperature is 30℃-35℃, water/soil ratios is 15:1-25:1, submergence-time by water is 12-18 h and pH value of acid rains is 3.82-3.73. 展开更多
关键词 Upland fields of yellow soil Soil F release Dissolved active P of runoff Impacting factor
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