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THE ROLE OF CLOUDE/RADIATION IN LONG-RANGE NUMERICAL WEATHER PREDICTION
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作者 郑庆林 Kuo-NanLiou 《Acta meteorologica Sinica》 SCIE 1989年第5期603-617,共15页
We investigate the role of clouds and radiation in the general circulation of the atmosphere using a model designed for 30-day predictions.Comprehensive verifications of 30-day predictions for the 500 hPa geo- potenti... We investigate the role of clouds and radiation in the general circulation of the atmosphere using a model designed for 30-day predictions.Comprehensive verifications of 30-day predictions for the 500 hPa geo- potential height field have been carried out,using the data from ECMWF objective analyses that cover the period from May 5 to June 3,1982.We perform three model simulations,including experiments with interac- tive cloud formation,without clouds,and without radiative heating.The latter two experiments allow us to study the effects of cloud/radiation interactions and feedbacks on the predicted vertical velocity,and the meridional and zonal wind profiles,averaged over a 30-day period. We demonstrate that the Hadley circulation is maintained by the presence of clouds.The radiative cooling in the atmosphere intensifies the vertical motion in low latitudes and,to some extent,also strengthens the overall meridional circulation.The meridional winds are correctly reproduced in the model if clouds are incorporated. The zonal winds are significantly affected by clouds and radiative cooling.Without an appropriate incor- poration of these physical elements,the model results would deviate significantly from observations.The presence of clouds strengthens the westerlies in middle and high levels.In May,the northerly movement of the jet stream over eastern Asia is,in part,associated with the presence of clouds. 展开更多
关键词 THE ROLE OF cloude/radiation IN LONG-RANGE NUMERICAL WEATHER PREDICTION
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Effect of Scattered Solar Radiation on the Informativeness of Polarization Lidar Studies of High-Level Clouds
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作者 Ignatii Samokhvalov Ilia Bryukhanov +5 位作者 Ivan Akimov Olesia Kuchinskaia Maxim Penzin Denis Romanov Evgeny Ni Ivan Zhivotenyuk 《Journal of Environmental & Earth Sciences》 2025年第6期148-156,共9页
During daylight laser polarization sensing of high-level clouds(HLCs),the lidar receiving system generates a signal caused by not only backscattered laser radiation,but also scattered solar radiation,the intensity and... During daylight laser polarization sensing of high-level clouds(HLCs),the lidar receiving system generates a signal caused by not only backscattered laser radiation,but also scattered solar radiation,the intensity and polarization of which depends on the Sun’s location.If a cloud contains spatially oriented ice particles,then it becomes anisotropic,that is,the coefficients of directional light scattering of such a cloud depend on the Sun’s zenith and azimuth angles.In this work,the possibility of using the effect of anisotropic scattering of solar radiation on the predictive ability of machine learning algorithms in solving the problem of predicting the HLC backscattering phase matrix(BSPM)was evaluated.The hypothesis that solar radiation scattered on HLCs has no effect on the BSPM elements of such clouds determined with a polarization lidar was tested.The operation of two algorithms for predicting the BSPM elements is evaluated.To train the first one,meteorological data were used as input parameters;for the second algorithm,the azi-muthal and zenith angles of the Sun’s position were added to the meteorological parameters.It is shown that there is no significant improvement in the predictive ability of the algorithm. 展开更多
关键词 High-Level clouds(HLCs) Polarization Lidar Backscattering Phase Matrix(BSPM) Sun’s Azimuthal and Zenith Angles Scattered Solar radiation cloud Microphysics Machine Learning(ML) Random Forest
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Differentiated Cloud-Radiation Characteristics over East Asian Subtropical and Tropical Regions Revealed by CMIP6 Models
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作者 WU Rui-xue LI Jian-dong +4 位作者 XU Jian-jun ZHANG Yu LIAO Xiao-qing LIU Chun-lei DU Zhen-cai 《Journal of Tropical Meteorology》 2025年第1期43-63,共21页
Pronounced climatic differences occur over subtropical South China(SC)and tropical South China Sea(SCS)and understanding the key cloud-radiation characteristics is essential to simulating East Asian climate.This study... Pronounced climatic differences occur over subtropical South China(SC)and tropical South China Sea(SCS)and understanding the key cloud-radiation characteristics is essential to simulating East Asian climate.This study investigated cloud fractions and cloud radiative effects(CREs)over SC and SCS simulated by CMIP6 atmospheric models.Remarkable differences in cloud-radiation characteristics appeared over these two regions.In observations,considerable amounts of low-middle level clouds and cloud radiative cooling effect appeared over SC.In contrast,high clouds prevailed over SCS,where longwave and shortwave CREs offset each other,resulting in a weaker net cloud radiative effect(NCRE).The models underestimated NCRE over SC mainly due to weaker shortwave CRE and less cloud fractions.Conversely,most models overestimated NCRE over SCS because of stronger shortwave CRE and weaker longwave CRE.Regional CREs were closely linked to their dominant cloud fractions.Both observations and simulations showed a negative spatial correlation between total(low)cloud fraction and shortwave CRE over SC,especially in winter,and exhibited a positive correlation between high cloud fraction and longwave CRE over these two regions.Compared with SCS,most models overestimated the spatial correlation between low(high)cloud fraction and SWCRE(LWCRE)over SC,with larger bias ranges among models,indicating the exaggerated cloud radiative cooling(warming)effect caused by low(high)clouds.Moreover,most models struggled to describe regional ascent and its connection with CREs over SC while they can better reproduce these connections over SCS.This study further suggests that reasonable circulation conditions are crucial to simulating well cloud-radiation characteristics over the East Asian regions. 展开更多
关键词 cloud fraction cloud radiative effect CMIP6 model South China South China Sea
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Cloud-Aerosol-Radiation (CAR) Ensemble Modeling System: Overall Accuracy and Efficiency 被引量:4
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作者 Feng ZHANG Xin-Zhong LIANG +2 位作者 曾庆存 Yu GU Shenjian SU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第4期955-973,共19页
The Cloud Aerosol- Radiation (CAR) ensemble modeling system has recently been built to better un- derstand cloud/aerosol/radiation processes and determine the uncertainties caused by different treatments of cloud/ae... The Cloud Aerosol- Radiation (CAR) ensemble modeling system has recently been built to better un- derstand cloud/aerosol/radiation processes and determine the uncertainties caused by different treatments of cloud/aerosol/radiation in climate models. The CAR system comprises a large scheme collection of cloud, aerosol, and radiation processes available in the literature, including those commonly used by the world's leading GCMs. In this study, detailed analyses of the overall accuracy and efficiency of the CAR system were performed. Despite the different observations used, the overall accuracies of the CAR ensemble means were found to be very good for both shortwave (SW) and longwave (LW) radiation calculations. Taking tile percentage errors for July 2004 compared to ISCCP (International Satellite Cloud Climatology Project) data over (60~N, 60~S) as an example, even among the 448 CAR members selected here, those errors of the CAR ensemble means were only about -0.67% (-0.6 W m-2) and -0.82% (-2.0 W m-2) for SW and LW upward fluxes at the top of atmosphere, and 0.06% (0.1 W m-2) and -2.12% (-7.8 W m 2) for SW and LW downward fluxes at the surface, respectively. Furthermore, model SW frequency distributions in July 2004 covered the observational ranges entirely, with ensemble means located in the middle of the ranges. Moreover, it was found that the accuracy of radiative transfer calculations can be significantly enhanced by" using certain combinations of cloud schemes for the cloud cover fraction, particle effective size, water path, and optical properties, along with better explicit treatments for unresolved cloud structures. 展开更多
关键词 cloud radiative forcing radiation CAR ENSEMBLE
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Dynamic and Thermodynamic Features of Low and Middle Clouds Derived from Atmospheric Radiation Measurement Program Mobile Facility Radiosonde Data at Shouxian, China 被引量:7
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作者 Jinqiang ZHANG Hongbin CHEN +1 位作者 Xiang'ao XIA Wei-Chyung WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第1期21-33,共13页
By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal w... By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal wind speed above the cloud layers was higher than those within and below cloud layers.The maximum balloon ascent speed(5.3 m s^-1) was located in the vicinity of the layer with the maximum cloud occurrence frequency(24.4%),indicating an upward motion(0.1-0.16 ms^-1).The average thickness,magnitude and gradient of the temperature inversion layer above single-layer clouds were117±94 m,1.3±1.3℃ and 1.4±1.5℃(100 m)^-1,respectively.The average temperature inversion magnitude was the same(1.3℃) for single-low and single-middle clouds;however,a larger gradient[1.7±1.8℃(100 m)^-1]and smaller thickness(94±67 m) were detected above single-low clouds relative to those above single-middle clouds[0.9±0.7℃(100 m)^-1 and157±120 m].For the two-layer cloud,the temperature inversion parameters were 106±59 m,1.0±0.9℃ and 1.0±1.0℃(100 m)^-1 above the upper-layer cloud and 82 ± 60 m,0.6±0.9℃ and 0.7±0.6℃(100 m)^-1 above the low-layer cloud.Absolute differences between the cloud-base height(cloud-top height) and the lifting condensation level(equilibrium level)were less than 0.5 km for 66.4%(36.8%) of the cases analyzed in summer. 展开更多
关键词 RADIOSONDE cloud dynamics THERMODYNAMICS
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On the Radiative Properties of Ice Clouds:Light Scattering, Remote Sensing,and Radiation Parameterization 被引量:13
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作者 Ping YANG Kuo-Nan LIOU +3 位作者 Lei BI Chao LIU Bingqi YI Bryan A.BAUM 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第1期32-63,共32页
Presented is a review of the radiative properties of ice clouds from three perspectives: light scattering simulations, remote sensing applications, and broadband radiation parameterizations appropriate for numerical ... Presented is a review of the radiative properties of ice clouds from three perspectives: light scattering simulations, remote sensing applications, and broadband radiation parameterizations appropriate for numerical models. On the subject of light scattering simulations, several classical computational approaches are reviewed, including the conventional geometric-optics method and its improved forms, the finite-difference time domain technique, the pseudo-spectral time domain technique, the discrete dipole approximation method, and the T-matrix method, with specific applications to the computation of the singlescattering properties of individual ice crystals. The strengths and weaknesses associated with each approach are discussed.With reference to remote sensing, operational retrieval algorithms are reviewed for retrieving cloud optical depth and effective particle size based on solar or thermal infrared(IR) bands. To illustrate the performance of the current solar- and IR-based retrievals, two case studies are presented based on spaceborne observations. The need for a more realistic ice cloud optical model to obtain spectrally consistent retrievals is demonstrated. Furthermore, to complement ice cloud property studies based on passive radiometric measurements, the advantage of incorporating lidar and/or polarimetric measurements is discussed.The performance of ice cloud models based on the use of different ice habits to represent ice particles is illustrated by comparing model results with satellite observations. A summary is provided of a number of parameterization schemes for ice cloud radiative properties that were developed for application to broadband radiative transfer submodels within general circulation models(GCMs). The availability of the single-scattering properties of complex ice habits has led to more accurate radiation parameterizations. In conclusion, the importance of using nonspherical ice particle models in GCM simulations for climate studies is proven. 展开更多
关键词 ice clouds light scattering remote sensing radiative property parameterization
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Preface to the Special Issue:Aerosols,Clouds,Radiation,Precipitation,and Their Interactions 被引量:1
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作者 Xiquan DONG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第2期133-134,共2页
The treatment of aerosols, clouds, radiation, and precipitation in climate models, in addition to their interactions and as- sociated feedbacks, has long been one of the largest sources of uncertainty in predicting an... The treatment of aerosols, clouds, radiation, and precipitation in climate models, in addition to their interactions and as- sociated feedbacks, has long been one of the largest sources of uncertainty in predicting any potential future climate changes. Although many improvements have been made in CMIP5, aerosols, clouds, radiation, and their feedbacks are still a problem in climate models, as concluded in IPCC AR5 and published papers. Many studies have shown that modeled aerosols, clouds, radiation, and precipitation agree with observations within a certain range on a global scale; however, large biases occur at the regional scale. Characterizing the effects of aerosols and clouds on energy and the hydrological cycle and understanding the interactions among aerosols, clouds, radiation, and precipitation, are critical for weather forecasting and climate models. Significant improvements are needed, which require advanced observations and modeling at a range of spatial and temporal scales. 展开更多
关键词 Preface to the Special Issue AEROSOLS cloudS radiation PRECIPITATION
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Effect of Macrophysical Parameters of Clouds on Broadband Solar Radiation(295-2800 nm) at a Subtropical Location 被引量:1
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作者 M.El-Nouby ADAM 《Atmospheric and Oceanic Science Letters》 2011年第3期181-185,共5页
The present study describes the effect of clouds (macro-physical parameters) on global solar radia- tion (G). Data from four years of hourly measurements of G on a horizontal surface were used. These data were col... The present study describes the effect of clouds (macro-physical parameters) on global solar radia- tion (G). Data from four years of hourly measurements of G on a horizontal surface were used. These data were collected at the South Valley University (SVU) meteoro- logical research station (26.2~N, 32.7~E, 96 m above mean see level. In addition, the cloud modification factor for G (CMF~)was estimated in three cases: high-level, mid-level, and low-level clouds. For every level, the variation of hourly CMF~ as a function of cloud amount (CA) was illustrated. A third-order polynomial between hourly values of CMFc and CA was established. Fur- thermore, the effect of CA in the attenuation of G relative to its corresponding value in cloudless conditions is dis- cussed. For cloud cover 〉 88%, G was reduced by 54%, 34%, and 28% by low-, mid-, and high-level clouds, re- spectively. 展开更多
关键词 cloudS global solar radiation cloud modifi-cation factor EGYPT
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Estimation of Global Solar Radiation Using Clearness Index and Cloud Transmittance Factor at Trans-Himalayan Region in Nepal 被引量:1
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作者 Khem N. Poudyal Binod K. Bhattarai +1 位作者 Balkrishna Sapkota Berit Kjeldstad 《Energy and Power Engineering》 2012年第6期415-421,共7页
This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Mete... This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available. 展开更多
关键词 Global Solar radiation SEASONAL Variation cloud TRANSMITTANCE FACTOR CLEARNESS Index Coefficient of Determination High HIMALAYA Region
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Recent progress on in-situ characterization of laser additive manufacturing process by synchrotron radiation 被引量:2
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作者 Wenquan Lu Liang Zhao +2 位作者 Zhun Su Jianguo Li Qiaodan Hu 《Journal of Materials Science & Technology》 2025年第14期29-46,共18页
Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex ... Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex laser-matter interaction,melt flow,and defect formation during LAM due to extremely large temperature gradient,fast cooling rate,and small time(millisecond)and space(micron)scales.The emergence of synchrotron radiation provides a feasible approach for in situ observation of the LAM process.This paper outlines the current development in real-time characterization of LAM by synchrotron radiation,including laser-matter interaction,molten pool evolution,solidification structure evolution,and defects formation and elimination.Furthermore,the future development direction and application-oriented research are also discussed. 展开更多
关键词 Laser additive manufacturing Synchrotron radiation Melt pool DEFECT
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Effects of cloud,atmospheric water vapor,and dust on photosynthetically active radiation and total solar radiation in a Mongolian grassland 被引量:1
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作者 Tserenpurev BAT-OYUN Masato SHINODA Mitsuru TSUBOn 《Journal of Arid Land》 SCIE 2012年第4期349-356,共8页
Photosynthetically active radiation (PAR) is an important input parameter for estimating plant produc- tivity due to its key role in the growth and development of plants. However, a worldwide routine network for sys... Photosynthetically active radiation (PAR) is an important input parameter for estimating plant produc- tivity due to its key role in the growth and development of plants. However, a worldwide routine network for sys- tematic PAR measurements is not yet established, and PAR is often calculated as a constant fraction of total solar radiation (SR). Although the ratio of PAR to SR (PAR/SR) has been reported from many places, few studies have been performed for dry regions. The present study was therefore carried out in an arid region of Mongolia to obtain PAP-JSR and examine its dependency on sky clearness (the clearness index), water vapor in the atmosphere and aeolian dust. Continuous measurements of PAR and SR were taken every one second using quantum and pyranometer sensors, respectively, and the readings were averaged and recorded at intervals of 30 minutes for a period of 12 months. The lowest monthly mean daily PAR/SR occurred in April (0.420), while the highest ratio was observed in July (0.459). Mean daily PAR/SR during plant growing season (May-August) was estimated to be 0.442, which could be useful for modeling plant productivity in the study area. The annual mean daily PAR/SR (0.435) was lower than the values reported in many previous studies. This difference could be explained with the regional variation in climate: i.e. drier climatic condition in the study area. PAR/SR was negatively correlated with the clearness index (r= -0.36, P〈0.001), but positively with atmospheric water vapor pressure (r=0.47, P〈0.001). The average PAR/SR was significantly lower (P=0.02) on the dusty days compared to the non-dust days. Water vapor in the atmosphere was shown to be the strongest factor in the variation of PAR/SR. This is the first study examining PAR/SR under a semi-arid condition in Mongolia. 展开更多
关键词 clearness index dust storm photosynthetically active radiation total solar radiation water vapor pressure
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Variation of sulfate aerosol concentrations over the western Pacific and their effect on clouds, radiation and precipitation 被引量:1
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作者 F.Parungo J.Rosinski +1 位作者 M.L.C.Wu C.T.Nagamoto 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第4期521-534,共14页
Under bilateral cooperation between the United States of America and the People's Republic of China, a series of research cruises were conducted over the western Pacific Ocean. It was found that a) the non-sea-sal... Under bilateral cooperation between the United States of America and the People's Republic of China, a series of research cruises were conducted over the western Pacific Ocean. It was found that a) the non-sea-salt sulfate aerosol particles are the major source of cloud condensation nuclei, b) the population of clouds and the total albedo are proportional to the concentration of condensation nuclei and consequently to the concentration of the non-sea-salt aerosol particles, and c) the amount of rainfall is inversely proportional to the concentration of non-sea-salt sulfate aerosol particles. It seems that anthropogenic sulfate aerosol particles affect the regional planetary albedo and climate and that the contribution from biogenically derived sulfate aerosol particles is of lesser importance. 展开更多
关键词 data Variation of sulfate aerosol concentrations over the western Pacific and their effect on clouds radiation and precipitation OVER
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Estimation of Hourly Solar Radiation at the Surface under Cloudless Conditions on the Tibetan Plateau Using a Simple Radiation Model 被引量:1
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作者 梁宏 张人禾 +2 位作者 刘晶淼 孙治安 程兴宏 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2012年第4期675-689,共15页
In this study, the clear sky hourly global and net solar irradiances at the surface determined using SUNFLUX, a simple parameterization scheme, for three stations (Gaize, Naqu, and Lhasa) on the Tibetan Plateau were... In this study, the clear sky hourly global and net solar irradiances at the surface determined using SUNFLUX, a simple parameterization scheme, for three stations (Gaize, Naqu, and Lhasa) on the Tibetan Plateau were evaluated against observation data. Our modeled results agree well with observations. The correlation coefficients between modeled and observed values were 〉 0.99 for all three stations. The relative error of modeled results, in average was 〈 7%, and the root-mean-square variance was 〈 27 W m-2. The solar irradiances in the radiation model were slightly overestimated compared with observation data; there were at least two likely causes. First, the radiative effects of aerosols were not included in the radiation model. Second, solar irradiances determined by thermopile pyranometers include a thermal offset error that causes solar radiation to be slightly underestimated. The solar radiation absorbed by the ozone and water vapor was estimated. The results show that monthly mean solar radiation absorbed by the ozone is 〈 2% of the global solar radiation (〈 14 W m-2). Solar radiation absorbed by water vapor is stronger in summer than in winter. The maximum amount of monthly mean solar radiation absorbed by water vapor can be up to 13% of the global solar radiation (95 W m-2). This indicates that water vapor measurements with high precision are very important for precise determination of solar radiation. 展开更多
关键词 solar radiation numerical simulation Tibetan Plateau
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Radiation investigation behind 4.7 km/s shock waves with nitrogen using a square section shock tube 被引量:1
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作者 Senhao Zhang Yuzhe Zhang +6 位作者 Yixin Xu Tianrui Bai Kai Luo Renjie Li Qiu Wang Xin Lin Fei Li 《Acta Mechanica Sinica》 2025年第3期13-22,共10页
The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium rad... The thermochemical non-equilibrium phenomena encountered by hypersonic vehicles present significant challenges in their design.To investigate the thermochemical reaction flow behind shock waves,the non-equilibrium radiation in the visible range using a shock tube was studied.Experiments were conducted with a shock velocity of 4.7 km/s,using nitrogen at a pressure of 20 Pa.To address measurement difficulties associated with weak radiation,a special square section shock tube with a side length of 380 mm was utilized.A high-speed camera characterized the shock wave’s morphology,and a spectrograph and a monochromator captured the radiation.The spectra were analyzed,and the numerical spectra were compared with experimental results,showing a close match.Temperature changes behind the shock wave were obtained and compared with numerical predictions.The findings indicate that the vibrational temperatures are overestimated,while the vibrational relaxation time is likely underestimated,due to the oversimplified portrayals of the non-equilibrium relaxation process in the models.Additionally,both experimental and simulated time-resolved profiles of radiation intensity at specific wavelengths were analyzed.The gathered data aims to enhance computational fluid dynamics codes and radiation models,improving their predictive accuracy. 展开更多
关键词 Nitrogen radiation NON-EQUILIBRIUM Spectral measurement Shock waves Shock tube
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A cloud optical and microphysical property product for the advanced geosynchronous radiation imager onboard China's Fengyun-4 satellites: The first version 被引量:2
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作者 Chao Liu Yuxing Song +5 位作者 Ganning Zhou Shiwen Teng Bo Li Na Xu Feng Lu Peng Zhang 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第3期52-57,共6页
风云四号作为中国新一代静止气象卫星,提供了高时空分辨率的监测产品。本文介绍风云四号搭载的先进地球同步轨道辐射成像仪AGRI的云光学和微物理特性产品.该产品包含了基于双光谱通道反演的云光学厚度和云粒子有效半径产品,以及基于机... 风云四号作为中国新一代静止气象卫星,提供了高时空分辨率的监测产品。本文介绍风云四号搭载的先进地球同步轨道辐射成像仪AGRI的云光学和微物理特性产品.该产品包含了基于双光谱通道反演的云光学厚度和云粒子有效半径产品,以及基于机器学习的云识别和云相态产品。与时空匹配的主动卫星观测结果对比显示,该产品的云识别和云相态的准确率分别在95%和85%;该产品提供的云光学厚度和云有效粒径与经典的MODIS产品的相关系数达到0.76和0.63.团队将持续优化和更新该云光学和微物理特性定量产品,服务风云四号卫星定量应用。 展开更多
关键词 风云四号 先进地球同步轨道辐射成像仪 云相态 云光学厚度 云有效粒子半径
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Radiation reduction modification of sp^(2) carbon-conjugated covalent organic frameworks for enhanced photocatalytic chromium(Ⅵ) removal 被引量:1
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作者 Shouchao Zhong Yue Wang +6 位作者 Mingshu Xie Yiqian Wu Jiuqiang Li Jing Peng Liyong Yuan Maolin Zhai Weiqun Shi 《Chinese Chemical Letters》 2025年第5期277-282,共6页
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ... A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy. 展开更多
关键词 Covalent organic framework Gamma radiation Photocatalytic reduction CHROMIUM Water purification
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A new radioactive microsphere:Y-90 carbon microsphere for selective internal radiation therapy of advanced liver cancer 被引量:1
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作者 Xiaosheng Zhao Jie Gao +13 位作者 Kun Shi Chixiang Zhang Wenliang Ma Guo Lyu Jun Zhang Jing Lu Qiangqiang Liu Xianjin Luo Kunru Yu Jianguo Li Qiang Ge Jiming Cai Chang Liu Zhiyong Qian 《Chinese Chemical Letters》 2025年第8期360-365,共6页
Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and pote... Radioactive microspheres have demonstrated excellent therapeutic effects and good tolerance in the treatment of unresectable primary and secondary liver malignancies.This is attributed to precise embolization and potent anti-tumor effect.However,certain limitations such as unstable loading,perfusion stasis,heterogeneous distribution,ectopic distribution,and insufficient dosage,restrict their clinical application.Herein,a novel personalized Y-90 carbon microsphere with high uniformity,high specific activity and high availability(^(90)Y-HUACM)is presented.It is synthesized through planar molecular complex adsorption and chemical deposition solidification.^(90)Y-HUACM exhibited controllable size,excellent biocompatibility,outstanding in vitro and in vivo stability.The radiolabeling efficiency of Y-90 exceeded 99%and the leaching rate of Y-90 is far below 0.1%.Furthermore,the excellent anti-tumor effect,nuclide loading stability,anti-reflux characteristics,precise embolization,and biosafety of^(90)Y-HUACM were validated in a rabbit VX2liver tumor model.In summary,this new,high-performance,and customizable radioactive microsphere provides a superior choice for selective internal radiation treatment of advanced liver cancer is expected to be rapidly applied in clinical practice. 展开更多
关键词 Carbon microsphere Yttrium-90 Selective internal radiation therapy Livercancer RADIOACTIVE
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Dimethylsulfide and Coral Bleaching: Links to Solar Radiation, Low Level Cloud and the Regulation of Seawater Temperatures and Climate in the Great Barrier Reef 被引量:1
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作者 Graham Jones Mark Curran +1 位作者 Hilton Swan Elisabeth Deschaseaux 《American Journal of Climate Change》 2017年第2期328-359,共32页
Coral reefs produce atmospheric dimethylsulfide (DMSa) which oxidises to non-sea-salt (nss) sulfate aerosols, precursors of cloud condensation nuclei (CCN) and low level cloud (LLC), reducing solar radiation and regul... Coral reefs produce atmospheric dimethylsulfide (DMSa) which oxidises to non-sea-salt (nss) sulfate aerosols, precursors of cloud condensation nuclei (CCN) and low level cloud (LLC), reducing solar radiation and regulating sea surface temperatures (SSTs). Here we report measurements of solar radiation, SST, LLC, DMS flux, , and rainfall before, during and after a major coral bleaching event at Magnetic Island in the central Great Barrier Reef (GBR). Measurements are compared with those made at the nearby fringing reef of Or-pheus Island where coral bleaching did not occur. Extreme solar radiation levels occurred from November to late January and could have reflected cloud radiative effects that increased downwelling of solar radiation. High levels of LLC often coincided with high periodic fluxes of DMS from the unbleached coral reef at Orpheus Island (e.g. 14 - 20 μmol·m-2·d-1), in direct contrast to the very low fluxes of DMS that were emitted from the bleached, human-impacted Magnetic Island fringing reef (nd-0.8 μmol·m-2·d-1) when SSTs were >30°C. Continuous SSTs measurements at the Magnetic Island reef revealed various heating and cooling periods, interspersed with stable SSTs. Cooling periods (negative climate feedback) ranged from -1°C to -3°C (7 day mean -1.6°C), and often seemed to occur during low tides, periodic pulses of DMS flux and LLC, keeping SSTs °C. In contrast warming periods of +1°C to +3°C (positive climate feedback, 7 day mean +1.52°C), seemed to occur during increasing tides, decreasing DMS flux and low to medium levels of LLC which increased solar radiation and caused SSTs over 30°C and corals to bleach. Alternation between these two states or types of feedback is indicated in this research and may be a function of enhanced scattering of solar radiation from nss-sulfate aerosols that originate from oxidation of DMSa produced from the coral reefs in the GBR. The net radiative forcing from clouds can be as high as four times as large as the radiative forcing from a doubling of CO2 levels in the atmosphere, which needs to be taken into account when ascribing coral bleaching events in the GBR solely to GHG warming. Further studies are needed to more critically assess the importance of this GBR coral reef-cloud feedback to the climate of northern Australia and the western Pacific, where the greatest biomass of coral reefs occurs. 展开更多
关键词 DIMETHYLSULFIDE Low Level cloud CLIMATE Feedback CORAL BLEACHING
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Point Reg Net: Invariant Features for Point Cloud Registration Using in Image-Guided Radiation Therapy 被引量:1
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作者 Zhengfei Ma Bo Liu +1 位作者 Fugen Zhou Jingheng Chen 《Journal of Computer and Communications》 2018年第11期116-125,共10页
In image-guided radiation therapy, extracting features from medical point cloud is the key technique for multimodality registration. This novel framework, denoted Control Point Net (CPN), provides an alternative to th... In image-guided radiation therapy, extracting features from medical point cloud is the key technique for multimodality registration. This novel framework, denoted Control Point Net (CPN), provides an alternative to the common applications of manually designed keypoint descriptors for coarse point cloud registration. The CPN directly consumes a point cloud, divides it into equally spaced 3D voxels and transforms the points within each voxel into a unified feature representation through voxel feature encoding (VFE) layer. Then all volumetric representations are aggregated by Weighted Extraction Layer which selectively extracts features and synthesize into global descriptors and coordinates of control points. Utilizing global descriptors instead of local features allows the available geometrical data to be better exploited to improve the robustness and precision. Specifically, CPN unifies feature extraction and clustering into a single network, omitting time-consuming feature matching procedure. The algorithm is tested on point cloud datasets generated from CT images. Experiments and comparisons with the state-of-the-art descriptors demonstrate that CPN is highly discriminative, efficient, and robust to noise and density changes. 展开更多
关键词 Medical Image REGISTRATION POINT cloud Deep Learning INVARIANT FEATURE
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Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite
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作者 JiaWen Tang Sai Zhang +8 位作者 FuLiang Xiao HongMing Yang Si Liu YiHua He Chang Yang YuYue Jin ZhouKun Deng Ping Li Archie James Johnston 《Earth and Planetary Physics》 EI CAS 2025年第1期188-193,共6页
Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u pling.Similar emissions have been observed in all magnetic planet magnetospheres of the... Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u pling.Similar emissions have been observed in all magnetic planet magnetospheres of the solar system.In this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) hemisphere.The distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic field.In addition,the occurrence rate on the nightside clearly increases as the AE^(*) index increases.This study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions. 展开更多
关键词 asymmetry auroral kilometric radiation interplanetary magnetic field
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