极区冬季电离层加热实验研究（三）——低电离层分析

使用低电离层加热条件下,非麦克斯韦碰撞等离子体非相干散射的理论模型,我们对我国2008年1月进行的极区冬季电离层加热实验进行了分析.分析结果表明,本次实验在低电离层区域得到了显著的电子温度增强现象,最大增幅百分比达到了168.9%.基于上述理论模型,我们进一步反演了非麦克斯韦指数,并由其计算出了加热电场强度,这对电离层加热的精确数值仿真有着重要的意义.     

Wave-mean flow interaction and its relationship with the atmospheric energy cycle with diabatic heating

In a linear system, the wave characteristics depend strongly on the distributions with height of wind ve-locity and static stability. The simplest case is for con-stant wind and static stability (e.g., isothermal atmos-phere with pressure and density exponentially de-creasing with height). In such circumstances there is no convergence or divergence in wave energy flux, therefore, no energy exchange between the wave and mean flow. In the atmosphere wind speed varies with increasing height, inte…     

Thermal transformations in laser-heated chloritized annite

Chloritized annite from the Irizar granite has been used for laser-heating experiments, following the procedures used for ⁴⁰Ar–³⁹Ar dating (heating steps in the 600–1080 °C temperature range). Four runs, at different temperatures, have been characterized using transmission electron microscopy, electron diffraction, micro-Raman and micro-IR spectroscopies. The water loss was evaluated by thermogravimetry. The chlorite domains break down first forming (001) amorphous layers, that later coalesce to rounded, equant inclusions and finally recrystallize to olivine and spinels plus silica glass. These phases occur within negative crystals hosted in ordered dehydrated annite, produced by dehydration and annealing of the starting annite. Dehydrated annite, olivine and spinels display topotactic relationships, determined by the common orientation of closely packed oxygen layers.     

中国西南汛期降水异常及影响因子

用１９５１～１９９２年３１个站的降水资料，作自然正交分解研究了近４２年汛期降水（４～９月）变化异常的时空分布，得到３种降水型。在此基础上通过相关函数和谱分析讨论了副高强度、副高强度、副高面积指数、副高西伸脊点、南方涛动指数、高原加热指数对西南汛期降水和降水型的影响作用和影响方式     

炎热干旱地区一种节能空调系统的初讨

搭建了热管式间接蒸发冷却器实验台，提出将热管式间接蒸发冷却器应用于空调系统中，在炎热干旱地区既满足了人体热舒适性的要求，又节约了初投资及运行费用。     

Pore-fluid pressures and frictional heating on a fault surface

This study considers the effects of heat transfer and fluid flow on the thernal, hydrologic, and mechanical response of a fault surface during seismic failure. Numerical modeling techniques are used to account for the coupling of the thermal, fluid-pressure, and stress fields. Results indicate that during an earthquake the failure surface is heated to a tempeature required for the thermal expansion of pore fluids to balance the rate of fluid loss due to flow and the fluid-volume changes due to pore dilatation. Once this condition is established, the pore fluids pressurize and the shear strength decreases rapidly to a value sufficient to maintain the thermal pressurization of pore fluids at near-lithostatic values. If the initial fluid pressure is hydrostatic, the final temperature attained on the failure surface will increase with depth, because a greater pressure increase can occur before a near-lithostatic pressure is reached. The rate at which thermal pressurization proceeds depends primarily on the hydraulic characteristics of the surrounding porous medium, the coefficient of friction on the fault surface, and the slip velocity. If either the permeability exceeds 10^–15 m² or the porous medium compressibility exceeds 10^–8 Pa^–1, then frictional melting may occur on the fault surface before thermal pressurization becomes significant. If the coefficient of friction is less than 10^–1 and if the slip velocity is less than 10^–2 msec^–1, then it is doubtful that either thermal pressurization or frictional melting on the fault surface could cause a reduction in the dynamic shear strength of a fault during an earthquake event.     

北半球冬季平流层温度和Brewer-Dobson环流对11 a太阳循环的响应

采用北京气候中心大气辐射模式(BCC-RAD)、日本气象厅JRA-55月平均再分析资料,研究了北半球冬季低纬度平流层上、下两个温度异常区对太阳周期的响应及其机制。结果表明,太阳活动偏强年,低纬度的上平流层温度暖异常是由臭氧短波加热异常引起的,它在中纬度的上平流层激发出异常强西风,阻碍行星波正常上传,由波破碎驱动的Brewer-Dobson环流也减弱,该环流上升支减弱的动力加热作用导致了低纬度的下平流层暖异常。     

The Persistent Heavy Rainfall over Southern China in June 2010：Evolution of Synoptic Systems and the Effects of the Tibetan Plateau Heating

This study investigates influencing weather systems for and the effect of Tibetan Plateau （TP）’s surface heating on the heavy rainfall over southern China in June 2010, focusing on the four persistent heavy rainfall events during 14-24 June 2010. The ma jor weather systems include the South Asian high, midlatitude trough and ridge, western Pacific subtropical high in the middle troposphere, and shear lines and eastward-moving vortices in the lower troposphere. An ensemble of convection-permitting simulations （CTL） is carried out with the WRF model for these rainfall events, which successfully reproduce the observed evolution of precipitation and weather systems. Another ensemble of simulations （SEN） with the surface albedo over the TP and its southern slope changed artificially to one, i.e., the surface does not absorb any solar heating, otherwise it is identical to CTL, is also performed. Comparison between CTL and SEN suggests that the surface sensible heating of TP in CTL significantly affects the temperature distributions over the plateau and its surroundings, and the thermal wind adjustment consequently changes atmospheric circulations and properties of the synoptic systems, leading to intensified precipitation over southern China. Specifically, at 200 hPa, anticyclonic and cyclonic anomalies form over the western and eastern plateau, respectively, which enhances the southward cold air intrusion along the eastern TP and the divergence over southern China;at 500 hPa, the ridge over the northern plateau and the trough over eastern China are strengthened, the southwesterly flows along the northwestern side of the subtropical high are intensified, and the positive vorticity propagation from the plateau to its downstream is also enhanced significantly;at 850 hPa, the low-pressure vortices strongly develop and move eastward while the southwesterly low-level jet over southern China strengthens in CTL, leading to increased water vapor convergence and upward motion over the precipitation region.     

THE RELATIONSHIP BETWEEN THE ATMOSPHERIC HEATING SOURCE/SINK ANOMALIES OF ASIAN MONSOON AND FLOOD/DROUGHT IN THE YANGTZE RIVER BASIN IN THE MEIYU PERIOD

NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper. Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007. The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part. As a result, relationships between an atmospheric heating source (hereafter called ) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper. The results are shown as follows. The flood/drought to the north of Yangtze River (NYR) was mainly related to the over the East Asia summer monsoon region: when the over the Philippines through Western Pacific and the south China was weakened (strengthened), it would probably result in the flood (drought) in NYR; and the precipitation on the south side of Yangtze River (SYR) was related to the over the east Asia and Indian summer monsoon region: when the over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened (weakened), and the over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened (strengthened), it will lead to flood (drought) in SYR.     

管道热屈曲动力过程数值模拟

运输高温高压油气的海底管道会发生整体热屈曲现象。管道热屈曲过程中可能会产生平衡状态的跃迁(snapthrough),且这样的跃迁过程必然会伴随着动力响应。管道热屈曲动力过程中侧向弹出的速度以及轴向缩进的速度对管土相互作用参数的取值有很大影响,然而关于管道热屈曲动力过程的研究却很少。本文给出了数值模拟过程中管道系统阻尼值和升温速率的确定方法,研究了管道初始几何缺陷以及海床参数对管道热屈曲动力过程的影响。