天山造山带及邻区孕震应力场及断裂带活动性特征的数值实验分析

天山造山带构造环境复杂,活动断裂带和强震分布广泛,且主要分布于阿尔泰山、天山、西昆仑—帕米尔弧形构造带上,尤以天山地区最为集中.迄今为止,天山造山带地区的主要断裂带的活动特征与孕震应力场特征之间的动力学机理尚未有清晰的认识.本文以GPS等实际观测数据为约束,建立有限元数值模型,计算了研究区域地壳形变、应力/应变积累速率、弹性应变能密度以及库仑应力变化率等关键因素.模拟计算结果显示地表速度场与研究区域实际GPS观测值基本一致,且主要断裂带上弹性应变能密度分布与实际地震活动性也基本吻合,验证了数值模型和结果的可靠性.结合最新的观测和数值模拟结果分析发现,研究区的断层和地震活动性主要受控于近南北向的主压应力,与主要观测特征相一致.同时,帕米尔高原北部边界带—塔什库尔干断裂（TKF）、天山造山带南边界的东侧—迈丹断裂（MDF）、兴地断裂（XDF）库仑应力增大明显,在未来强震发生的可能性较高,应予密切关注.     

长江倒灌鄱阳湖原因及发生条件的量化指标

江湖倒灌对鄱阳湖流域水动力变化和流域水环境保护等方面有重要影响,正确认识江湖倒灌原因和倒灌发生条件对明晰江湖倒灌作用机理、研究倒灌强度和倒灌影响范围等方面具有重要意义。在剖析江湖倒灌原因的基础上,从非恒定流洪水波传播的角度出发,结合鄱阳湖为"河相"、"湖相"时江湖倒灌的特点,提出了长江作用强度指标和鄱阳湖作用强度指标,在此基础上引入江湖作用综合强度函数,依据实测资料,分析研究了江湖作用综合强度函数的关系表达式、江湖倒灌发生条件及量化指标。经验证,所提出的江水倒灌量化指标可区分江湖顶托和江湖倒灌现象,可实现对鄱阳湖为"河相"、"湖相"时的江湖倒灌预测,且提高了预测江湖倒灌起止时间、总历时和年内发生次数的准确率,成果可用于江湖关系研究和鄱阳湖流域水资源综合利用工程实践中。     

汶川地震前后川滇块体应变与断裂变形特征研究

利用1999—2007和2007—2009年GPS资料,采用块体变形模型和GPS速度剖面研究了川滇地区的分阶段变形特征,结果显示川西北-滇中-滇西南块体主压应变率方向由北向南呈顺时针方向旋转;安宁河断裂、则木河断裂存在剪切应变积累,小江断裂南段以走滑为主、北段以应变积累为主;汶川地震对丽江-小金河断裂中南段、安宁河断裂和金沙江断裂有一定影响,对则木河断裂、小江断裂和红河断裂的影响较小。     

天山地区SAR数据雪盖制图研究

在分析合成孔径雷达（ＳＡＲ）成像机理及雪盖参数散射特性的基础上，利用航天飞机搭载的成像雷达（ＳＩＲ－Ｃ）获取的天山Ｃ波段、多极化ＳＡＲ数据，进行提取雪盖信息的实验。数据通过预处理、散射系数图像的计算、去噪、入射角改正等处理后，利用ＢＡＹＥＳ监督分类方法产生该地区的雪盖分类图。实验结果表明，利用多波段、多极化ＳＡＲ进行雪盖制图是可行的。     

流动环境中倾斜浮力射流的积分方法

给出了基于积分方法的一种倾斜浮力射流的数学模型,且流速、密度和浓度差剖面假定为高斯分布,并导出了用来封闭该数学模型的较为完全的掺入率公式.用计算精度较高的有限分析法计算这类定解问题,计算结果与试验资料基本吻合.     

基于Atmega16的多点温湿度测控系统设计

介绍了基于Atmega16单片机为检测和控制核心,并同多个数字温度传感器DS18B20及模拟湿度传感器HS1101构成温度与湿度的测控系统.给出了系统的总体设计方案、硬件设计及软件框图.所设计的粮情测控系统具有优良的性价比,通过系统软硬件的联合调试说明,该系统可以满足对温湿度及烟雾进行实时监控的需要,具有稳定性好、精度高等特点,有一定的应用价值.     

Evaluating the role of climate and tectonics during non-steady incision of the Yellow River: evidence from a 1.24 Ma terrace record near Lanzhou,China

The competing roles of bedrock uplift and climatic change in the formation of fluvial terraces remain uncertain. Most of recent studies have attributed terrace formation to climatic changes and held that, even in tectonically active settings, climate variations control cycles of terrace planation and abandonment. Based on field investigations of loess-paleosol sequences, magnetostratigraphy and optically stimulated luminescence (OSL) dating, we develop a new chronology for a spectacular flight of terraces along the Yellow River near Lanzhou, China over past 1.24 Ma. All the terraces are strikingly similar in that they have several meters of paleosol developed directly above fluvial deposits on the terrace treads, suggesting that the abandonment of each terrace due to river incision occurs during the transition from glacial to interglacial climates. However, the ages of terraces cluster in two relatively short time periods (1.24–0.86 Ma and 0.13 Ma – present). During the intervening time between 0.86 Ma and 0.13 Ma, terraces either did not form or were not preserved. We suggest that this record indicates that rock uplift rates varied through time and influenced terrace formation/preservation. Thus, our results demonstrate the utility of deep chronologic records from fluvial terraces for deconvolving the effects of tectonics and climate on fluvial incision.     

预应力混凝土渡槽抗震性能的试验研究

基于预应力混凝土渡槽的低周反复荷载试验,对其受力过程、破坏形态、滞回曲线、刚度退化、耗能能力等抗震性能进行了研究与分析。试验结果表明：预应力混凝土渡槽的破坏形态为弯剪破坏,滞回曲线在加载的初期阶段表现出一定的捏拢效应,滞回曲线总体呈明显的梭形,且较为丰满,耗能能力强,抗震性能优良;配筋合适的预应力混凝土渡槽在加载初期对裂缝控制具有良好的表现,渡槽整体具有良好的延性;在整个加载过程中,渡槽试件的刚度退化明显,刚度退化主要集中在开裂后至屈服这一阶段。     

Application of a self adaptive method to the simulation of the tidal front in the Huanghai Sea

A self adaptive three-dimensional baroclinic model is designed. A horizontal temperature gradient is used to control the grid size, which can improve computational precision in the fronts without inordinately increasing computation in the whole area. A simulation of the development and disappearance of the front in the Huanghai Sea is conducted with this model. Simulations of temperature distribution throughout the year are also conducted. The computational result agrees well with the observation.     

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