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Precipitation Microphysical Characteristics of Typhoon Ewiniar(2018) before and after Its Final Landfall over Southern China

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Advances in Atmospheric Sciences 2023年第6期40卷 1005-1020页

作者： Lu FENG Hui XIAO xiantong liu Sheng HU Huiqi LI liusi XIAO Xiao HAO Guangzhou Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510641China Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological AdministrationGuangzhou 510641China Guangzhou Meteorological Observatory China Meteorological AdministrationGuangzhou 511430China

In this paper, the evolution of the microphysical characteristics in different regions(eyewall, inner core, and outer rainbands) and different quadrants [downshear left(DL), downshear right(DR), upshear left(UL), and upshear right(UR)]during the final landfall of Typhoon Ewiniar(2018) is analyzed using two-dimensional video disdrometer and S-band polarimetric radar data collected in Guangdong, China. Due to the different types of underlying surfaces, the periods before landfall(mainly dominated by underlying sea surface) and after landfall(mainly dominated by underlying land surface) are also analyzed. Both before landfall and after landfall, the downshear quadrants had the dominate typhoon precipitation. The outer rainbands had more graupel than the inner core, resulting in a larger radar reflectivity, differential reflectivity, specific differential phase shift, and mass-weighted mean diameter below the melting layer. Compared with other regions, the eyewall region had the smallest mean logarithmic normalized intercept parameter before landfall and the smallest mean mass-weighted mean diameter and the largest mean logarithmic normalized intercept parameter after landfall. The hydrometeor size sorting was obvious in the eyewall and inner core(especially in the eyewall) after landfall. A high concentration of large raindrops fell in the DL quadrant, and more small raindrops fell in the UR quadrant. Although the icephase process and warm rain process were both important in the formation of tropical cyclone precipitation, the warm rain process(ice-phase process) contributed more liquid water before landfall(after landfall). This investigation provides a reference for improving the microphysical parameterization scheme in numerical models.

关键词： tropical cyclone precipitation microphysics raindrop size distribution southern China

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从出土医学文献看《黄帝内经》中的经脉系统

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中华中医药杂志 2024年第1期39卷 82-86页

作者：何仙童柳长华成都中医药大学成都610000

中医学元典《黄帝内经》自诞生以来,上下五千年,相关研究著作、论文可谓层出不穷,其作为后世经脉医学之祖,源远流长。然而经脉的起源与流派是多元化的,至今流传最广,成为权威学说的理论便是《灵枢·经脉》所形成的十二经脉系统“阴阳相... 详细信息

中医学元典《黄帝内经》自诞生以来,上下五千年,相关研究著作、论文可谓层出不穷,其作为后世经脉医学之祖,源远流长。然而经脉的起源与流派是多元化的,至今流传最广,成为权威学说的理论便是《灵枢·经脉》所形成的十二经脉系统“阴阳相贯,如环无端”。而其他流派的经脉系统或因为社会、政治、文化等因素失传而埋没于历史的长河中。文章从出土医学文献的角度,结合传世的《黄帝内经》文本,试图梳理《黄帝内经》秦汉时期所蕴含的数种经脉系统,如阴脉阳脉系统、六脉系统、十脉系统、十一脉系统等,为经脉医学的传承和创新提供借鉴。

关键词：《黄帝内经》经脉系统出土文献考证

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Effect of Aerosol Particles on Orographic Clouds:Sensitivity to Autoconversion Schemes

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Advances in Atmospheric Sciences 2020年第2期37卷 229-238页

作者： Hui XIAO Yan YIN Pengguo ZHAO Qilin WAN xiantong liu Guangzhou Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510641China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China College of Atmospheric Science Chengdu University of Information&TechnologyChengdu 610225China

Aerosol particles can serve as cloud condensation nuclei(CCN)to influence orographic clouds.Autoconversion,which describes the initial formation of raindrops from the collision of cloud droplets,is an important process for aerosol-cloud-precipitation systems.In this study,seven autoconversion schemes are used to investigate the impact of CCN on orographic warm-phase clouds.As the initial cloud droplet concentration is increased from 100 cm^(-3)to 1000 cm^(-3)(to represent an increase in CCN),the cloud water increases and then the rainwater is suppressed due to a decrease in the autoconversion rate,leading to a spatial shift in surface precipitation.Intercomparison of the results from the autoconversion schemes show that the sensitivity of cloud water,rainwater,and surface precipitation to a change in the concentration of CCN is different from scheme to scheme.In particular,the decrease in orographic precipitation due to increasing CCN is found to range from-87%to-10%depending on the autoconversion scheme.Moreover,the surface precipitation distribution also changes significantly by scheme or CCN concentration,and the increase in the spillover(ratio of precipitation on the leeward side to total precipitation)induced by increased CCN ranges from 10%to 55%under different autoconversion schemes.The simulations suggest that autoconversion parameterization schemes should not be ignored in the interaction of aerosol and orographic cloud.

关键词： orographic cloud precipitation autoconversion aerosol particles

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Vertical distribution characteristics of PM in the surface layer of Guangzhou

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Particuology 2015年第3期13卷 3-9页

作者： Xuejiao Deng Fei Li Yuanhong Li Jianyong Li Hongzhi Huang xiantong liu Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological Administration(CMA) Guangdong Atmosphere Sounds Technology Centre

Measurements of particulate matter （PM）, i.e., PM10, PM2.5, and PM1, have been performed on the Can- ton Tower, a landmark building in Guangzhou, at heights of 121 and 454 m since November 2010, using a GRIMM 180 aerosol particle spectrometer （Germany）. Analyses of data from November 2010 to May 2013 showed that the annual average values of PM10, PM2.5, and PM 1 at the observation height of 121 m above the ground were 44.1, 38,2, and 34.9 μg/m3, respectively, and those at 454m above the ground were 35.7, 30,4, and 27.5 μg/m3, respectively. By considering the values of the secondary concentration limits given in the Ambient Air Quality Standards issued in 2012, it was observed that the annual average values of PM10 at the observation heights of 121 and 454 m, as well as those of PM2.5 at 454 m, reached those standards. Furthermore, the over-standard amplitude of the annual average value of PM2.5 at the observation height of 121 m was 9.1%. During the observation period, the maximum daily average val- ues of PM10, PM2.5, and PMI at the observation height of 121 m were 183.3, 144.8, and 123.8 μg/m3, respectively, and those at 454 m were 102.8, 92.7, and 86.4 μg/m3. The daily average values of PM10 at the observation height of 454 m were not above the standards. The over-standard frequencies of the daily average values of PM10 and PM2.5 at the observation height of 121 m were 0.6% and 10,7% respectively, and the over-standard amplitudes were 9.0% and 24.4%, respectively. The over-standard frequency of the daily average value of PM2.5 at the observation height of 454 m was 2.0%, and the over-standard amplitude was 10.4%. Accordingly, it can be stated that the air at the observation height 454 m above the ground did not reach the secondary limit of the new standards. The pollution was most serious during winter, and the air was relatively cleaner during summer, Overall, the vertical distributions of PM10, PM2.5, and PMI decreased with height. The lapse rates showed the following sequence： PMIO 〉 PM2.5 〉 PM1, which indi

关键词： PM10PM2.5PM10ver-standardVertical distributionSurface layer

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Raindrop Size Distribution Parameters Retrieved from Guangzhou S-band Polarimetric Radar Observations

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Journal of Meteorological Research 2018年第4期32卷 571-583页

作者： xiantong liu Qilin WAN Hong WANG Hui XIAO Yu ZHANG Tengfei ZHENG Lu FENG Institute of Tropical and Marine Meteorology of China Meteorological Administration Guangzhou 510640 Guangzhou Meteorological Observatory Guangzhou 511430

According to the statistical shape-slope （μ-A） relationship observed for the first time by several 2D-Video-Distro-meters （2DVD） in southern China, a constrained gamma （C-G） model was proposed for the retrieval of rain drop size distributions （DSDs） from Guangzhou S-band polarimetric radar observations. Two typical precipitation processes were selected to verify the accuracy of the retrieval scheme. The p-A relationship： A = 0.0241μ^2 ＋ 0.867μ ＋ 2.453 was obtained based on the 2DVD observation results from at Huizhou Longmen station, which is a very representat-ive location in the area. Relying on the Guangzhou polarimetric radar measurements of radar reflectivity （ZHH） and differential reflectivity （ZDR）, the gamma （F） size distribution parameters （No, μ, and A） can be retrieved by the C-G model retrieval scheme. The results show that the Guangzhou polarimetric radar retrievals of DSDs were close to the 2DVD observations at Guangzhou Maofengshan station. The rain rate, mass mean diameter, and normalized inter-cept parameter of radar retrievals were in good agreement with the 2DVD observations, and the relative errors were less than 10%. The overall accuracy of the retrieval scheme was high. The retrieval scheme has established the rela-tionship between the polarimetric radar measurements and gamma size distribution parameters. It will be helpful to in-depth research and application of the dual-polarization radar data in microphysical precipitation processes analysis, as well as convection-resolved numerical model data assimilation and prediction effect evaluation.

关键词： Guangzhou S-band polarimetric radar 2D-Video-Disdrometer raindrop size distribution retrieval microphysics

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莺歌海盆地黄流组一段沉积物源综合识别

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海洋地质前沿 2024年第6期40卷 62-74页

作者：胡高伟刘显童陈杨邱隆伟李彦丽中海石油(中国)有限公司海南分公司海口570100 中国石油大学(华东)地球科学与技术学院青岛266000

通过重矿物直观比对法确定了莺歌海盆地黄流组一段沉积物中各物源区的重矿物特征,并初步认识了其古母岩特征。研究区周围存在三大主要物源区,即海南岛、越南北部(红河)及越南中部。结果表明,越南物源以铁矿物、钛矿等沉积岩型重矿物组... 详细信息

通过重矿物直观比对法确定了莺歌海盆地黄流组一段沉积物中各物源区的重矿物特征,并初步认识了其古母岩特征。研究区周围存在三大主要物源区,即海南岛、越南北部(红河)及越南中部。结果表明,越南物源以铁矿物、钛矿等沉积岩型重矿物组合为主;海南物源以锆石、电气石、金红石等酸性火山岩型重矿物组合为主。基于余弦距离及皮尔森相关系数的谱系聚类结果表明,莺歌海盆地黄流组一段锆石、电气石、金红石、锐钛矿、白钛矿等矿物受成岩作用影响较小,为该时期的稳定矿物组合。综合稳定重矿物复杂拓扑网络、地震属性、地震剖面及锆石年龄等方法对主导物源区进行划分,确定了莺歌海盆地东方13区及东方1区的部分扇体主要受控于越北红河物源,东方13区及东方29区的绝大多数扇体主要受越中物源及海南北部物源的双重影响,乐东区受控于海南南部物源。基于海南南部物源的古物源分布模式,建立了重矿物-地震特征-锆石年代学的物源识别方法。

关键词：物源识别重矿物指数拓扑复杂网络地震属性莺歌海盆地

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照明光污染防治现状及对中国的建议

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环境污染与防治 2024年第1期46卷 128-133页

作者：郝影贾大功刘圣春郑皓皓白煜李宪同天津市生态环境监测中心天津300191 天津大学精密仪器与光电子工程学院微光机电系统技术教育部重点实验室(天津大学)天津300072 天津商业大学机械工程学院天津300134 中国环境监测总站北京100012 中国环境保护产业协会北京100037

随着城市建设加快,照明技术快速发展,人造光源导致的光污染问题日益凸显,已经成为城市环境污染防治的新领域。光污染防治工作在国外已开展了几十年,具有丰富的管理经验和技术基础。在综述国外照明光污染研究进展的基础上,指出中国光污... 详细信息

随着城市建设加快,照明技术快速发展,人造光源导致的光污染问题日益凸显,已经成为城市环境污染防治的新领域。光污染防治工作在国外已开展了几十年,具有丰富的管理经验和技术基础。在综述国外照明光污染研究进展的基础上,指出中国光污染防治管理现状及问题,并提出对策与建议,为国家综合施策、统筹推进光污染防治,建立国家光环境监督管理体系提供科学依据。

关键词：照明光污染人造光源光环境监管

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Mid-wavelength InAs/GaSb type-Ⅱ superlattice barrier detector with nBn design and M barrier

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Optoelectronics Letters 2023年第10期19卷 577-582页

作者： liu Zhaojun ZHU Lianqing LU Lidan DONG Mingli ZHANG Dongliang ZHENG xiantong School of Opto-Electronic Engineering Changchun University of Science&TechnologyChangchun130022China Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing Information Science&Technology UniversityBeijing100192China Key Laboratory of Optical Fiber Sensing and System Beijing Information Science&Technology UniversityBeijing100016China

This study reports the performance of an InAs/GaSb type-Ⅱ superlattices(T2SLs) detector with nBn structure for mid-wavelength infrared(MWIR) detection. An electronic band structure of M barrier is calculated using 8-band k·p method, and the nBn structure is designed with the M barrier. The detector is prepared by wet etching, which is simple in manufacturing process. X-ray diffraction(XRD) and atomic force microscope(AFM) characteristics indicate that the detector material has good crystal quality and surface morphology. The saturation bias of the spectral response measurements at 77 K is 300 m V, and the device is promising to work at a temperature of 140 K. Energy gap of T2SLs versus temperature is fitted by the Varshni curve, and zero temperature bandgap Eg(0), empirical coefficients α and β are extracted. A dark current density of 3.2×10-5A/cm2and differential resistance area(RA) product of 1.0×104Ω·cm2are measured at 77 K. The dominant mechanism of dark current at different temperature ranges is analyzed. The device with a 50% cutoff wavelength of 4.68 μm exhibits a responsivity of 0.6 A/W, a topside illuminated quantum efficiency of 20% without antireflection coating(ARC), and a detectivity of 9.17×1011cm·Hz1/2/W at 77 K and 0.3 V.

关键词： InAs/GaSb barrier structure

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Effect of growth interruption time on the quality of InAs/GaSb type-Ⅱ superlattice grown by molecular beam epitaxy

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Optoelectronics Letters 2023年第3期19卷 155-158页

作者： liu Zhaojun ZHU Lianqing ZHENG xiantong LU Lidan ZHANG Dongliang liu Yuan School of Opto-Electronic Engineering Changchun University of Science and TechnologyChangchun 130022China Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing Information Science&Technology UniversityBeijing 100192China

We systematically investigate the influence of growth interruption time on the properties of In As/Ga Sb type-II superlattices(T2SLs) epitaxial materials grown by molecular beam epitaxy(MBE). X-ray diffraction(XRD) and atomic force microscope(AFM) are used to characterize the material quality and morphology. The full width at half maximum(FWHM) of the XRD 0th satellite peaks ranges from 32″ to 41″, and the root mean square(RMS) roughness on a 5 μm×5 μm scan area is 0.2 nm. Photoluminescence(PL) test is used to reveal the influence of the growth interruption time on the optical property. Grazing incidence X-ray reflectivity(GIXRR) measurements are performed to analyze the roughness of the interface. The interface roughness(0.24 nm) is optimal when the interruption time is 0.5 s. The crystal quality of T2SLs can be optimized with appropriate interruption time by MBE, which is a guide for the material epitaxy of high performance T2SL infrared detector.

关键词： roughness interrupt beam

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Daytime precipitation identification scheme based on multiple cloud parameters retrieved from visible and infrared measurements

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Science China Earth Sciences 2014年第9期57卷 2112-2124页

作者： liu xiantong liu Qi FU YunFei LI Rui Key Laboratory of the Atmospheric Composition and Optical Radiation Chinese Academy Sciences School of Earth and Space SciencesUniversity of Science and Technology of China Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological Administration

Visible and infrared(VIR) measurements and the retrieved cloud parameters are commonly used in precipitation identification algorithms, since the VIR observations from satellites, especially geostationary satellites, have high spatial and temporal resolutions. Combined measurements from visible/infrared scanner(VIRS) and precipitation radar(PR) aboard the Tropical Rainfall Measuring Mission(TRMM) satellite are analyzed, and three cloud parameters, i.e., cloud optical thickness(COT), effective radius(Re), and brightness temperature of VIRS channel 4(BT4), are particularly considered to characterize the cloud status. By associating the information from VIRS-derived cloud parameters with those from precipitation detected by PR, we propose a new method for discriminating precipitation in daytime called Precipitation Identification Scheme from Cloud Parameters information(PISCP). It is essentially a lookup table(LUT) approach that is deduced from the optimal equitable threat score(ETS) statistics within 3-dimensional space of the chosen cloud parameters. South and East China is selected as a typical area representing land surface, and the East China Sea and Yellow Sea is selected as typical oceanic area to assess the performance of the new scheme. It is proved that PISCP performs well in discriminating precipitation over both land and oceanic areas. Especially, over ocean, precipitating clouds(PCs) and non-precipitating clouds(N-PCs) are well distinguished by PISCP, with the probability of detection(POD) near 0.80, the probability of false detection(POFD) about 0.07, and the ETS higher than 0.43. The overall spatial distribution of PCs fraction estimated by PISCP is consistent with that by PR, implying that the precipitation data produced by PISCP have great potentials in relevant applications where radar data are unavailable.

关键词：红外测量识别算法降水云云参数可见光白天静止卫星错误检测

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