环渤海葡萄涝渍指标构建及风险评估          下载免费PDF全文

毛红丹  霍治国  张蕾  杨建莹  孔瑞  李春晖  江梦圆 《应用气象学报》2022,33(1):92-103

以中国环渤海地区葡萄主产区为研究对象,利用1980-2019年研究区域内303个气象站逐日气象资料、葡萄发育期资料和葡萄涝渍灾情资料,基于相对湿润度方法构建葡萄逐日涝渍指数M5i,以历史灾情反演和灾变过程解析为主线,采用正态分布的Lilliefors检验和t分布区间估计等方法,构建适用于中国环渤海地区葡萄主产区的葡萄涝...  相似文献   

Dependence of the holmberg effect on separations between paired galaxies     

Xin-Fa Deng  Yong Xin  Jiang Peng  Ping Wu 《Astrophysics》2010,53(3):342-350

To investigate the dependence of the Holmberg effect of paired galaxies on three-dimensional separations, we have constructed four subsamples characterized by three-dimensional separations s ≤ 50 kpc, 50 kpc < s ≤ 100 kpc , 100kpc < s ≤150kpc , and 150 kpc < s ≤ 200 kpc , respectively. In this study, linear correlation coefficients and surplus standard deviations of color indices, luminosity, and size between two components of paired galaxies are calculated. It is found that there is a weak tendency for correlation coefficients of color indices to increase with decreasing three-dimensional separations, but such a tendency does not exist for ones of luminosity and size. We also note that there is no tendency for surplus standard deviations to decrease with decreasing three-dimensional separations. This suggests that it is still very difficult to clearly affirm the dependence of the Holmberg Effect of paired galaxies on three-dimensional separations.  相似文献   

Associations of decimetric type Ⅲ bursts with coronal mass ejections and Hα flares     

Yuan Ma  De-Yu Wang  Jun Lin    Shuo Dai  Xue-Fei Zhang National Astronomical Observatories of China / Yunnan Astronomical Observatory  Chinese Academy of Sciences  Kunming  China Purple Mountain Observatory  Nanjing  China Harvard-Smithsonian Center for Astrophysics  Cambridge  MA  USA 《中国天文和天体物理学报》2010,10(5)

We present a statistical study of decimetric type Ⅲ radio bursts,coronal mass ejections(CMEs),and Hα flares observed in the period from July 2000 to March2005.In total,we investigated 395 decimetric type Ⅲ radio burst events,21% of which showed apparent correlation to CMEs that were associated with Hα flares.We noticed that the Hα flares which were strongly associated with CMEs were gradual events,and82% of them took place before CMEs appeared in the field of view of LASCO C2;that most of the CME-associated radio bursts started in the frequency range around750 MHz with a frequency drifting rate of several hundred MHz s-1,of which both positive and negative ones were recognized; and that the correlation of type Ⅲ radio bursts to CMEs without associated flares is fairly vague,less than 9%.  相似文献   

The effect of metallicity on the minimum mass ratio of W Ursae Majoris-type systems     

Dengkai Jiang  Zhanwen Han  Cheng Liu  Jiancheng Wang  Lifang Li 《Astrophysics and Space Science》2010,329(1-2):283-286

According to the prevenient theoretical study, the minimum mass ratio for tidal stability of W Ursae Majoris (W UMa) systems is q _min?=(M ₂/M ₁)～0.071–0.078. However, the mass ratios of some observed W UMa binaries are smaller than the theoretical minimum mass ratio. Using Eggleton’s stellar evolution code, we study the effects of metallicity and evolution on the minimum mass ratio of W UMa systems (M ₁=1.2M _⊙). We assume that $k_{1}^{2}=k_{2}^{2}$ for the component’s dimensionless gyration radii and that the contact degree is about 70 per cent. We find that the dynamical stability of W UMa binaries depends on the metallicity of W UMa systems. For the W UMa systems at age = 0 Gyr, the distribution of the minimum mass ratio has a fairly wide range, from 0.083 to 0.064, with the metallicity range from Z=0.0001 to 0.03. W UMa systems with Z=0.01 have the smallest value of the minimum mass ratio, which is about 0.064. The existence of low-q systems can be explained partly by the dependence of the dimensionless gyration radius on the metallicity. In addition, the dependence of the minimum mass ratio on the evolution, as suggested by previously work, is confirmed.  相似文献   

AMR Simulations of Magnetohydrodynamic Problems by the CESE Method in Curvilinear Coordinates   总被引：1，自引：0，他引：1  

Chaowei Jiang  Xueshang Feng  Jian Zhang  Dingkun Zhong 《Solar physics》2010,267(2):463-491

The objective of this paper is to present new extensions of the space – time conservation element and solution element (CESE) method for simulations of magnetohydrodynamic (MHD) problems in general curvilinear coordinates by using an adaptive mesh refinement (AMR) grid system. By transforming the governing MHD equations from the physical space (x,y,z) to the computational space (ξ,η,ζ) while retaining the form of conservation, the CESE method is established for MHD in the curvilinear coordinates. Utilizing the parallel AMR package PARAMESH, we present the first implementation of applying the AMR CESE method for MHD (AMR-CESE-MHD) in both Cartesian and curvilinear coordinates. To show the validity and capabilities of the AMR-CESE-MHD code, a suite of numerical tests in two and three dimensions including ideal MHD and resistive MHD are carried out, with two of them in both Cartesian and curvilinear coordinates. Numerical tests show that our results are highly consistent with those obtained previously by other authors, and the results under both coordinate systems confirm each other very well.  相似文献   

青海天峻新关角隧道涌排水水源识别与量化分析     

彭红明  袁有靖  李铜邦  董高峰  刘毅  巴瑞寿 《地质科技情报》2022,41(1):60-70

涌排水严重影响隧道施工与运行安全,查明隧道涌排水的来源,是隧道防水止水重要科学依据.青海天峻新关角隧道南北洞口处的地下水排水量分别为10021,60877 m3/d,两者存在近50000 m3/d的差异,涌排水量大,且来源不明.基于水文地质条件分析,分别采集了新关角隧道隧址区内大气降水、不同类型地下水和隧道出口涌排水水...  相似文献   

自动建模客观分型方法在非汛期人工增雨中的应用     

陈晓红  胡雯  余金龙  袁野 《气象科技》2007,35(4):541-545

根据安徽省人工影响天气业务系统需要,利用NCEP 500 hPa高度场和风场格点资料及安徽省81站10年非汛期逐日降水资料,在客观分析天气形势基础上,结合预报员实践经验给出的不同系统影响安徽省时的关键区,计算机自动建模,形成逐日天气型日历,实现环流分型客观化。此方法识别条件实用,模型物理意义明确,自动化程度高,自动生成的逐日天气型日历,为安徽省非汛期人工增雨作业指挥系统提供了很好的天气预报参考依据。  相似文献   

南平市气象局视频会商系统建设   总被引：2，自引：0，他引：2  

江彩英  叶月珍  黄永玉  邱晓光 《气象科技》2007,35(4):610-612

南平市气象局基于政务网的可视化视频会商系统,将不同型号的省—地和地—县间视频会商系统级联在一起,把省—市会商面向辖区内县市局实时转发,降低会商系统的成本。通过此系统,地区气象台可以与省气象台及下属台站预报员及时的进行充分的天气预报交流,举办电视电话会议和业务培训等。  相似文献   

闽北汛期强降水中尺度特征分析   总被引：3，自引：0，他引：3  

张信华  蒋宗孝  付伟辉  黄元森  黄永玉 《气象科技》2007,35(3):351-354

为揭示闽北暴雨的中尺度规律,利用1980~2005年南平市10县(市、区)气象站5~6月雨量大于等于50mm达到或超过3个站的43个暴雨过程129个暴雨日的逐时降水自记资料,分析了汛期暴雨日雨团和强雨团的时空分布、强度及持续时间、移动规律、雨团与影响系统的关系以及地形对雨团的产生、分布、移动等的影响等,得出闽北汛期强降水的中尺度若干特征,其结论可为预报人员在业务实践中提供有益的参考。  相似文献   

广西凤凰山银矿床构造控矿与找矿方向研究   总被引：3，自引：0，他引：3  

雷英凭  甘琴  郑援 《矿物学报》2010,30(1)

广西凤凰山银矿床位于西大明山复式背斜北东端的次级褶皱断裂破碎带中。本文基于区域构造背景,研究了凤凰山银矿床构造对矿化蚀变的控制作用,分析了控矿构造组合样式及其形成机理。认为矿体产于NWW向压剪性断裂中的局部张性地段,断裂产状变化部位以及NWW向断裂与NW向断裂交会部位是成矿有利部位。  相似文献