“2010.12.11”云南冬季暴雨成因分析

 应用常规观测资料、FY-2C卫星云图和NCEP再分析资料,通过诊断分析研究了2010年12月11日发生在滇中及以南地区的云南暴雨天气过程.结果发现,这次冬季暴雨天气过程发生在有利的环流背景下,ITCZ位置偏北较活跃,孟湾存在大片对流云系,中印度洋10°N附近存在一支异常的大尺度西南气流,孟加拉湾低层有一个热带气旋生成,在卫星云图上表现出明显的气旋式云系,孟湾热带气旋和90°E附近的南支槽及槽前西南低空急流东移造成了这次暴雨天气过程;引发暴雨的水汽和能量由低空急流从孟加拉湾输送而来,充沛的水汽在云南上空强烈辐合,暴雨区θ_se呈陡立状,暴雨发生在低层辐合高层辐散的上升运动区,水汽通量散度辐合区和湿Q矢量辐合区与暴雨区对应较好.     

2007年夏季河套地区两次区域性大暴雨过程模拟分析

以2007年夏季发生在河套地区的两次大暴雨天气过程为对象,利用MM5中尺度数值预报模式对其发生发展过程进行数值模拟,通过与实况对比,表明模式对暴雨落区的模拟是成功,然后利用模式输出结果对暴雨形成机制在影响天气系统、水汽输送、不稳定层结和动力条件等方面进行了诊断分析。结果表明,两次大暴雨都发生中高纬十分稳定的环流形势下,在第一次暴雨过程中,西北涡和低空西南急流是其主要影响系统,低涡东侧的辐合和低层暖湿气流为暴雨的发生提供了良好的动力和水汽条件;在第二次暴雨过程中,500hPa切变线为其主要影响系统,高层强烈的抽吸作用为暴雨区提供了强劲的上升运动,弱冷空气与低层暖湿气流之间形成强烈位势不稳定为暴雨的发生发展提供有利的条件。第一次暴雨过程中一直有高通量水汽输入,水汽由来自孟加拉湾和南海的两股偏南气流合并而成;第二次暴雨过程的水汽有台风"帕布"东北侧的偏东气流输送。与第一次暴雨过程无冷空气作用不同,第二次暴雨过程中由于有弱冷空气侵入触发了不稳定能量释放,更有利于暴雨的产生和形成。低层螺旋度正值区与未来12～18h暴雨落区有较好的对应关系,暴雨区高层为螺旋度负值区,螺旋度这种高低层耦合是触发和维持暴雨的动力机制。     

一次江淮流域特大暴雨过程的观测分析

利用常规观测和NCEP/NCAR再分析资料,对2015年6月26-28日发生在江淮流域的一次梅雨锋暴雨过程进行诊断分析,得到以下结论:①此次暴雨发生在500hPa西风带系统中,冷暖空气交汇形成的梅雨锋及其切变线稳定维持在江淮流域上空,切变线南侧为强盛的西南低空急流;②暴雨过程主要有2条水汽来源,分别来自孟加拉湾和我国南海。水汽通量输送主要集中在800hPa以下,925hPa水汽通量辐合中心与强降水中心对应;③在降水区形成冷中心与其南侧高温高湿的不稳定气流对峙,形成温度密集带,有利于梅雨锋上中尺度对流系统的发生、发展和维持。     

武汉6.20特大暴雨的水汽供给特点

一九八二年六月二十日,武汉地区发生了一场历史上罕见的特大暴雨(6.20特大暴雨)。本文计算该特大暴雨区的水汽收支,发现这场特大暴雨的水汽来源,主要地700毫巴中间尺度偏西急流,将鄂西低空垂直辐合线上空堆积起来的水汽,向东传输到暴雨区的。这个特点与通常注意到的大尺度西南低空急流输送水汽的特点不同,主要不是从大气底部,而是从约700毫巴的高度向暴雨区内输送水汽.     

与低空急流相伴的暴雨天气诊断分析

 对1998年5月～2002年5月7例与低空急流相伴的云南全省性暴雨过程进行了合成诊断分析.结果表明:临近暴雨发生时,西南低空急流的形成应是云南暴雨产生的主要原因,暴雨天气通常出现在低空急流北侧风矢呈气旋性弯曲、风速递减的梯度十分明显的区域内;低空急流对于水汽和能量的输送起非常重要的作用,它一方面为暴雨的产生提供了所需要的大量水汽,另一方面又使得暴雨区低层大气增湿增暖,从而引起对流不稳定加强,为暴雨的发生提供大量的不稳定能量.湿位涡分析表明,暴雨发生前,冷暖空气在云南交汇,使大气温湿结构发生变化,θ_e等值面坡度加大,当低空急流移向对流不稳定区时,便有气旋性涡度剧烈发展,导致暴雨天气的发生.     

一次梅雨锋连续大暴雨过程的诊断分析

为了提高对梅雨锋暴雨过程的预报服务能力,利用常规观测资料、MICAPS天气图和FNL再分析等资料,对2020年7月8—10日梅雨锋连续大暴雨天气过程进行了诊断分析。结果表明:1)这是一次高水汽含量、强低空急流配合短波槽、切变线和梅雨锋天气尺度系统引发的连续大暴雨过程; 2)利用FNL再分析资料对过程的水汽、动力、热力条件进行了分析,表明25°～29°N在800 h Pa以下水汽含量丰富,湖南中东部和吉安地区有水汽通量大值区,向东北方向输送水汽并产生明显辐合,且伴有持续的上升运动; 3)南昌站的探空CAPE值呈现有利强降水的细长结构,且有明显的能量释放和再建过程; 4)稳定天气背景、持续的水汽输送和辐合以及不稳定能量的释放和再建是造成此次连续大暴雨过程的关键所在。研究成果为提高梅雨锋暴雨的预报服务能力提供了参考依据。     

河南省夏玉米生长季洪涝灾害的环流背景及水汽输送特征

采用1°×1°NCEP再分析资料及地面、高空实况观测资料,分析了2000年以来发生在淮河上游河南境内的4次持续性暴雨过程的大尺度环流背景和水汽输送特征.结果表明:淮河上游持续性暴雨有纬向型和经向型两类,以纬向型居多.两类暴雨的持续与副热带高压及长波槽脊的稳定维持密切相关,两类暴雨均发生在亚欧环流为两槽两脊的大尺度环流背景下(槽、脊位置不同),北方南下的冷空气与副热带高压外围的暖湿气流长时间交汇于淮河上游上空,致使该地区暴雨持续;4次持续暴雨过程的水汽来自于南海、孟加拉湾或东部海面,东边界和南边界是水汽的主要流入边界.     

抚州市一次连续性暴雨过程分析

利用常规气象资料,T639数值预报产品等资料对2014年6月19-22日抚州市出现连续性暴雨形成机制进行分析,结果表明:此次暴雨是在中高纬"两槽一脊"环流背景下产生,而中低层持续强劲的西南急流是这次暴雨的主要触发系统,持续的低空急流为暴雨区输送充足的水汽和不稳定能量,急流最大风速出口区辐合为暴雨形成提供了辐合上升的动力条件。过程期间,高低空散度场配置以及低空正涡度中心与强辐合区的叠加,表明在暴雨区内存在着大气上升运动。在大气处于高度不稳定状态下,地面存在辐合扰动,有利于中尺度对流系统的发生发展。     

超低空急流背景下的景德镇市大暴雨过程分析

分析了超低空背景下景德镇市大暴雨的特征,主要结论如下:景德镇市的大暴雨与超低空急流关系密切,有超8成的大暴雨伴有超低空急流或准超低空急流。在超低空急流背景下的大暴雨分为梅雨型、台风型、冷锋型、低涡型、高空偏北气流型和涌线型等6种形势,以梅雨型和低涡型居多。暴雨主要与中低层切变线密切相关。梅雨型有南北两支气流及相伴的带状(块状)副热带高压,台风型要形成两高一低的阻塞形势。暖区中的低空急流易在地面诱发辐合线,在冷锋型、涌线型等形势中在辐合线附近触发强降水。在低涡移向的右前方和上下重合的低涡中心易出大暴雨。高空偏北气流型多发生在7-8月,低空急流将副高控制区的高能、高湿空气向东北方向输送,与高空偏北气流构成强不稳定,在低空多层辐合系统的作用下,出现强降水。大暴雨过程中不伴有超低空急流的有大风速型、7至8月辐合型、副高型和低槽+切变+低涡+中层西南急流型。     

2010年4月11日上饶市暴雨过程天气分析

应用常规观测资料、中尺度站资料和T213数值预报产品,对2010年4月10日对流性暴雨天气的成因进行了分析。分析了产生暴雨的天气系统特征,产生暴雨的水汽条件和动力触发机制,给出了产生暴雨的对流云团演变特征。研究结果表明,这次暴雨是由高空低槽、中低层切变线、低空急流和地面低压的共同影响产生的。低层强盛的西南气流建立起水汽通道,把水汽源源不断地向暴雨区输送。低层较强的西北气流和强盛的暖湿气流相汇合,垂直涡度增大,辐合上升运动增强。地面冷锋前生成中尺度低压,加强了辐合上升运动。高层辐散与低层辐合相配合,有利于上升运动发展和维持。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with