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Advances in Atmospheric Sciences 2020年第1期37卷 105-116页

作者： Jianli MA Zhiqun HU meilin yang Siteng LI Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China

Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation *** prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the Bayesian *** PBB>PNB the gate belongs to the ML,and when PBBPNB the gate belongs to the ML,and when PBB

关键词： X-band polarimetric radar Bayesian method melting layer identification hydrometeor classification

Tree ring based drought variability in Northwest Tajikistan since 1895 AD

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Journal of Arid Land 2020年第3期12卷 413-422页

作者： yang meilin YU yang ZHANG Haiyan WANG Qian GAN Miao YU Ruide State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China School of Environment and Material Science Yantai UniversityYantai 264005China

Determining the mechanisms controlling the changes of wet and dry conditions will improve our understanding of climate change over the past hundred years,which is of great significance to the study of climate and environmental changes in the arid regions of Central *** trees are ecologically significant in the local environment,and therefore the tree ring analysis can provide a clear record of regional historical *** study analyzed the correlation between the tree ring width chronology of Juniperus turkestanica Komarov and the standardized precipitation evapotranspiration index(SPEI)in Northwest Tajikistan,based on 56 tree ring samples collected from Shahristan in the Pamir *** data including precipitation,temperature and the SPEI were downloaded from the Climate Research Unit(CRU)TS *** COFECHA program was used for cross-dating,and the ARSTAN program was used to remove the growth trend of the tree itself and the influence of non-climatic factors on the growth of the trees.A significant correlation was found between the radial growth of *** trees and the monthly mean SPEI of February–*** monthly mean SPEI sequence of February–April during the period of 1895–2016 was reconstructed,and the reconstruction equation explained 42.5%of the *** the past 122 a(1895–2016),the study area has experienced three wetter periods(precipitation above average):1901–1919,1945–1983 and 1995–2010,and four drier periods(precipitation below average):1895–1900,1920–1944,1984–1994 and 2011–*** spatial correlation analysis revealed that the monthly mean SPEI reconstruction sequence of February–April could be used to characterize the large-scale dry-wet variations in Northwest Tajikistan during the period of 1895–*** study could provide comparative data for validating the projections of climate models and scientific basis for managing water resources in Tajikistan in the context of climate change.

关键词： tree ring width chronology standardized precipitation evapotranspiration index(SPEI) drought Juniperus turkestanica Pamir region

The discovery of annually laminated sediments (varves) from shallow Sugan Lake in inland arid China and their paleoclimatic significance

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Science China Earth Sciences 2007年第8期50卷 1218-1224页

作者： ZHOU AiFeng CHEN FaHu QIANG MingRui yang meilin ZHANG JiaWu CAEP Key Laboratory of West China’s Environmental System(Ministry of Education)Lanzhou UniversityLanzhou 730000China

Detailed examination of sedimentary cores retrieved from Sugan Lake in the northern Qaidam Basin of northwest China’s Tibetan Plateau reveal that fine laminated beddings form in the sediments where water depth exceeds 3 m. Seasonal surface sediments trapped at the bottom of the lake suggest that sediments deposited during summer and autumn are mainly light colored monohydrocalcites, while those deposited in winter are dark organic matter, indicating that varve layers form under modern limnological conditions. Continuous varve sediments comprising four types have accumulated in the upper 5.5 m of Core SG03I from the center of the lake. All types exhibit clear seasonality indicative of annual deposition. Varve counts correspondence with 210Pb dates on recent sediments in the upper core suggest the continuous varves of the upper 5.5 m of the core formed in the late Holocene (2670 a BP). The Sugan Lake varve sequence is the first demonstration of annually laminated sediments re-ported in arid western China.

关键词： Sugan Lake varve Tibetan Plateau arid China

Distribution of functional microorganisms and its significance for iron, sulphur, and nitrogen cycles in reservoir sediments

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Acta Geochimica 2021年第6期40卷 961-972页

作者： Shuang Bai meilin yang Zheng Chen Ming yang Jing Ma Xue-Ping Chen Fushun Wang School of Environmental and Chemical Engineering Shanghai University99 Shangda RoadBaoShan DistrictShanghai 200444China Department of Health and Environmental Sciences Xi’an Jiaotong-Liverpool UniversitySuzhou 215123JiangsuChina

The biogeochemical cycles of sulphur(S),iron(Fe)and nitrogen(N)elements play a key role in the reservoir ***,the spatial positioning and interrelationship of S,Fe and N cycles in the reservoir sediment profile have not been explored to a greater ***,we measure the gradients of Fe^(2+),SO_(4)^(2-),NO_(3)^(-),NH_(4)^(+),DOC,TC and TN in the pore water of the sediment,and combining the vertical distribution of the functional microorganisms involved in S,Fe and N cyclings in the sediments to determine the redox stratification in the *** is found that the geochemical gradient of S,Fe and N of the reservoir sedimentary column is mainly defined by the redox process involved in the related functional *** to the type of electron acceptor,the sediment profile is divided into 3 redox intervals,namely aerobic respiration(0–10 cm),denitrification/iron reduction(10–28 cm)and sulfate reduction(28–32 cm).In the aerobic respiration zone,NH_(4)^(+)is oxidized by aerobic AOB to NO_(3)^(-)(0–5 cm),and Fe^(2+)is oxidized by microaerobic FeRB to Fe^(3+)(3–10 cm).In the denitrification/iron reduction zone,Acinetobacter and Pseudomonas,as the dominant NRB genera,may use nitrate as an electron acceptor to oxidize Fe^(2+)(11–16 cm).The dominant genera in SOB,such as Sulfururvum,Thiobacillus and Thioalkalispira,may use nitrate as an electron acceptor to oxidize sulfide,leading to SO_(4)^(2-)accumulation(14–24 cm).In the sulfate reduction zone,SO_(4)^(2-)is reduced by *** study found that functional microorganisms forming comprehensive local ecological structures to adapt to changing geochemical conditions,and which would be potentially important for the degradation and preservation of C and the fate of many nutrients and contaminants in reservoirs.

关键词： Reservoir sediment Geochemical cycle Microbial community Redox Denitrification

An Improved Method for Correction of Air Temperature Measured Using Different Radiation Shields

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Advances in Atmospheric Sciences 2014年第6期31卷 1460-1468页

作者： CHENG Xinghong SU Debin LI Deping CHEN Lu XU Wenjing yang meilin LI Yongcheng YUE Zhizhong WANG Zijing Public Meteorological Service Center China Meteorological Administration Support Center for Atmospheric Observing Technology Beijing Meteorological Bureau Beijing Observatory Station Beijing Meteorological Bureau Daxing District Bureau of Meteorology Beijing Meteorological Bureau

The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was *** were collected in the field at the Daxing weather station in Beijing from June 2011 to May *** air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson *** most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese *** measured errors changed sharply at sunrise and sunset,and reached maxima at *** diurnal variation characteristics were,naturally,related to changes in solar *** relationships between the record errors,global radiation,and wind speed were *** improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005）（NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected *** errors were reduced significantly after correction by either method for both *** error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively.

关键词： radiation shield measurement error impacts of solar zenith angle improved correction method

The Glass Transition Temperature and Liquid1-Liquid2 Relaxation of Star-Shaped Polystyrene

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Chemical Research in Chinese Universities 1987年第1期 47-51页

作者： Wang Jian,Liu Jingjiang,yang meilin and Shen Jiacong (Department of Chemistry,Jilin University,Changchun)

The glass transition temperature T and relaxation temperature T11 of a series of regular star-shaped polystyrenes were measured by using torsional braid analyzer(TEA) and linear *** results showed that Tg for star-shaped polymer increases with increas-ing branching degree whan the molecular weights of branch chains arethe same,but it is lower than that of linear polystyrene with the same molecular *** liquid 1iquid relaxation temperature T11 and the intensity of loss peak of star polystyrene also depend on branching ***-Tg transitions in star polystyrenes with DVB microgel nodule were proved by comparing two types of star polystyrenes.

关键词： The Glass Transition Temperature and Liquid1-Liquid2 Relaxation of Star-Shaped Polystyrene Star

多校区办学模式下异地校区科研建设存在的问题及其应对措施——以某高校珠海校区为例

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科技管理研究 2017年第12期37卷 91-96页

作者：龚梅琳杨杰暨南大学珠海校区广东珠海519000 暨南大学社会科学研究处广东广州510632

科研建设是教学科研型高校发展的重中之重,直接影响到学校的办学水平。在多校区办学模式下异地校区科研建设面临瓶颈,诸如现有经验不适应异地校区实际情况、管理体系难以直接延伸、科研人才培养创新机制缺乏等。为此,基于某高校珠海校... 详细信息

科研建设是教学科研型高校发展的重中之重,直接影响到学校的办学水平。在多校区办学模式下异地校区科研建设面临瓶颈,诸如现有经验不适应异地校区实际情况、管理体系难以直接延伸、科研人才培养创新机制缺乏等。为此,基于某高校珠海校区的实际情况,提出采取"内外结合"的发展模式、融合地方科研发展实际需求和创新科研人才培养模式等措施来提升异地校区的科研建设水平,促进异地校区的科研建设工作与主校区的协调发展。

关键词：多校区办学异地校区科研建设应对措施

基于非表面参考技术的机载双频降水反演结果分析

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遥感技术与应用 2014年第3期29卷 378-385,400页

作者：吴琼商建仰美霖杨虎中国科学院大气物理研究所中层大气与全球环境探测实验室北京100029 国家卫星气象中心北京100081 北京市气象局大气探测技术保障中心北京100089

双频降水测量雷达是我国计划发射的风云三号降水测量卫星上的主载荷。双频测量能够较好地估计粒子谱分布参数,提高降雨率定量反演的精度,对双频降水反演算法的研究是降水产品业务化的基础。首先介绍基于非SRT的双频降水反演算法的主要原... 详细信息

双频降水测量雷达是我国计划发射的风云三号降水测量卫星上的主载荷。双频测量能够较好地估计粒子谱分布参数,提高降雨率定量反演的精度,对双频降水反演算法的研究是降水产品业务化的基础。首先介绍基于非SRT的双频降水反演算法的主要原理,随后采用模拟数据对反演算法的精度进行检验,并选取机载雷达外场校飞试验中的实测数据,分析了机载雷达降雨探测的合理性。结果表明:双频反演的DSD参数基本合理,能够准确地反映出层云降水中亮带的峰值信息,并且和在轨同步观测的星载降水测量雷达PR的探测结果相近。此外,还探讨了随机选取的机载反射率因子廓线的双频反演结果以及可能引起反演误差的原因,结果发现相态转换的高度以及水的体积比可能对4km附近及其以上的区域有一定的影响,对4km以下的部分则影响不大。同时温度对反演结果的影响主要集中在3.5km附近,在其他高度层,温度的影响基本可以忽略。同时降雨率的精度还受到雷达系统误差的制约。总体而言,机载双频降水反演结果具有一定的精度,基本符合当时机载外场试验的实际天气状况,从而验证了机载雷达降雨探测的合理性。

关键词：双频降水反演算法机载双频降水雷达降雨率

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基于滴谱分布的机载雷达波束匹配情况研究

气象学报 2013年第3期71卷 547-554页

作者：吴琼商建仰美霖杨虎国家卫星气象中心北京100081 北京市气象局大气探测技术保障中心北京100089

基于机载双频测雨雷达外场校飞试验中获取的有效降水测量数据,利用Ku波段的雨衰系数和等效雷达反射率因子的比值估算了雨滴谱分布参数。在此基础上,通过米散射模拟计算了Ka波段在该滴谱分布下的等效雷达反射率因子,并和机载Ka波段衰减... 详细信息

基于机载双频测雨雷达外场校飞试验中获取的有效降水测量数据,利用Ku波段的雨衰系数和等效雷达反射率因子的比值估算了雨滴谱分布参数。在此基础上,通过米散射模拟计算了Ka波段在该滴谱分布下的等效雷达反射率因子,并和机载Ka波段衰减订正后的等效雷达反射率因子进行了比对。结果表明:两者的廓线基本重合,相关系数超过0.95,两部雷达探测的目标物一致,测量的雷达反射率因子的差异主要是由雷达频率的不同所引起的后向散射以及衰减的不同所造成的,波束匹配精度较高。此外,单频滴谱参数的估计依赖于单频衰减订正的精度。机载雷达外场试验中探测的都是弱降水,Ku波段衰减订正不会存在太大的误差,估计的滴谱较为可靠。必须指出的是,精确的参数估计仍然要借助双频雷达的反演方法。

关键词：机载双频降水雷达滴谱分布米散射

聚合物分子量经验分布与理论分布(Ⅰ)——三参数指数分布与Poisson分布

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高等学校化学学报 1989年第9期 944-947页

作者：杨梅林沈家骢吉林大学化学系吉林大学化学系

本文通过矩数分析给出了Poisson分布与三参数指数型分布的关系.这是由加聚物买验分布推断反应机理的初步尝试.

关键词：分子量分布聚合反应机理 Poisson分布三参数指数分布