The relations between modulus of elasticity and temperature in the context of the experimental simulation of rock weathering by fire

Fires occur frequently in many biomes and generate high temperatures on the ground surface. There are many field examples of fire causing rock disintegration. The simulation of fire in the laboratory (using a furnace) and the monitoring of changes in rock modulus of elasticity (with a Grindosonic apparatus), reveal that different rocks respond differently to heating. Significant decreases in elasticity occur at temperatures as low as 200°C and granites display particularly marked reductions. Extended periods of heating are not required for significant reductions to occur. It is postulated that the degree of change in elasticity as a result of simulated fire is such that rock outcrops subjected to real fires are likely to be sufficiently modified as to increase their susceptibility to erosion and weathering processes.     

不同覆盖条件对土壤水热分布影响的计算机模拟Ⅰ——数学模型

本文建立了用于数值解的不同覆盖条件下土壤二维水热运动数学模型。该模型中多孔材料覆盖层(砂砾、秸秆等)被当作传热多孔介质处理,对水分传输的影响被当乍具有一定阻力的阻挡层处理,且将油纸、塑膜及土面增温剂等均视为薄膜类材料。省略了许多假设条件,因而使覆盖效应的研究建立在更加科学的基础上,可以更为深入地了解覆盖层在不同气候条件下对土壤水分蒸发、入渗及地温影响机理和程度。为综合评价和选用农用覆盖材料及其参数提供了手段。     

利用马氏过程模拟和预测土壤侵蚀的动态演变─—以安徽省岳西县为例

本文根据安徽省岳西县１９５８－１９８２－１９９２年三个时期的遥感资料所编制的土壤侵蚀图，用点数转化法定量地分析岳西县上述两个阶段侵蚀演变和浸蚀类型之间的相互转化状况，确定相应的初始状态下（１９５８和１９８２）的转移概率矩阵，应用马尔科夫过程摸拟和预测岳西县土壤侵蚀及其格局的动态演变过程和未来演变趋势。     

Crustal Texture and Rheological Evolution of Tongbai－Dabie Orogenic Belt，China

Ｃｒｕｓｔａｌ　Ｔｅｘｔｕｒｅ　ａｎｄ　Ｒｈｅｏｌｏｇｉｃａｌ　Ｅｖｏｌｕｔｉｏｎ　ｏｆＴｏｎｇｂａｉ－Ｄａｂｉｅ　Ｏｒｏｇｅｎｉｃ　Ｂｅｌｔ，Ｃｈｉｎａ￥ＳｕｏＳｈｕｔｉａｎ（ＦａｃｕｌｔｙｏｆＥａｒｔｈＳｃｉｅｎｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓｉ...     

一种使用正交调制互补码的新方法

本文提出一种新的方案,可以用正交调制的方法,同时发射两组互补码,从而使得该系统对目标信号相关时间的要求由历来的“必须远大于雷达重复周期”降低到”只要远大于码的总长”。本文给出了用计算机进行仿真的结果。     

A laboratory simulation of mesoscale flow interaction with the Alps

A series of laboratory experiments, aimed at the simulation of some aspects of Alpine lee cyclogenesis has been carried out in the rotating tank of the Coriolis Laboratory of LEGI-IMG in Grenoble. Dynamic and thermodynamic processes, typical of baroclinic development triggered by the orography, were simulated. The background flow simulating the basic state of the atmosphere consisted of a stream of intermediate density fluid introduced at the interface between two fluid layers. The structure of the intermediate current was established by mixing fluid obtained from the upper layer of fresh water with fluid removed from the heavier salty layer below.The dynamical similarity parameters are the Rossby (Ro), Burger (Bu) and Ekman (Ek) numbers, although this last, owing to its small values, need not be matched between model and prototype, since viscous effects are not important for small time scales. The flow in both the prototype and laboratory simulation is characterized by hydrostatics; this requires (Ro²δ²/Bu)1 (where δ=H/L is the aspect ratio of the obstacle) which is clearly satisfied, in the atmosphere and oceans, and for the laboratory experiment.A range of experiments for various Rossby and Burger numbers were conducted which delimited the region of parameter space for which background flows akin to that found to the northwest of the Alps prior to baroclinic cyclogenesis events, were observed.One such experiment was carried out by placing a model of the Alps at the appropriate place in the flow field. The subsequent motion in the laboratory was observed and dye tracer motions were used to obtain the approximate particle trajectories. The density field was also analyzed to provide the geopotential field of the simulated atmosphere. Using standard transformations from the similarity analysis, the laboratory observations were related to the prototype atmosphere. The flow and the geopotential fields gave results compatible with the particular atmospheric event presented.     

吕梁市2005年9月20日暴雨过程分析

本文从天气形势、物理量场、卫星云图等方面对2005年9月20日出现在吕梁市的大到暴雨,局部大暴雨天气过程进行了综合分析,得到了一些有益的结论。     

回归分析方法在地震科学应用中的问题与探讨

分析了回归分析方法在地震科学应用中存在的问题,提出了按变量之间的物理关系进行分类回归的新观点。针对实际地震问题给出了具体的分类方案,从理论上论述了不同类型问题采用不同的回归方法的必要性。通过对实际地震问题分析,剖析了现有回归分析方法的优缺点和适用条件。在此基础上,对不同类型统计问题如何选用适当的回归分析方法提出了合理的建议。     

中国云南哀牢山含海蓝宝石伟晶岩的起源和成岩模拟实验研究

The Ailaoshan aquamarine-bearing pegmatites are associated with Proterozoic metamorphic rocks in the southern portion of the Ailaoshan fault-folded complex.The gem-bearing pegmatite mineralization zones of the region occur in areas generally consistent with the regional tectonic trend.The pegmatites are found in metamorphic rocks,migmatites and in the inner/outer contact zones of gneissoid granites. The Rb-Sr isochron drawn for the pegmatites is 26～31 Ma,(i.e.in Himalayan).The homogenization temperatures of melt and liquid inclusions in minerals vary from 185 to 920℃,which are comparable to the inclusions observed in banded migmatites and ptygmatic quartz veins in the surrounding metamorphic rocks. The mineralization fluids of the pegmatite were rich in HCO_3 and CO_2,and their compositional assemblages are comparable to metamorphic fluids.Results of H,O,C,Si etc.isotopic analyses and REE,and Be analyses indicates that the sources of mineralization components that formed the pegmatites are closely associated with metamorphic fluids and the enclosing metamorphic rocks. A pegmatite structure simulation experiment was conducted at high temperature and pressure(840℃and 1,500×105Pa.),with various metamorphic rock samples in a water-rich and volatile-rich environment.When the liquidus was reached,the temperature was gradually decreased at the rate of 5～10℃/day over a time period of three months.SEM energy-dispersive spectrum analyses were performed on the experimental products.A series of pegmatoid textures were observed including zonal texture,megacryst texture,drusy cavities,crystal druses,and vesicular texture along with more than ten types of minerals including plagioclase,microcline,quartz and biotite.Different metamorphic rock melts generated different mineral assemblages.Experiment results revealed that the partial melting of metamorphic rocks could form melts similar to pegmatite magmas. Based upon the geological characteristics,geochemistry,and pegmatite texture simulation experimental results,it is concluded that the mineralization components of Ailaoshan aquamarine-bearing pegmatites came from metamorphic rocks.The petrogenetic model for the origin of pegmatites is related to ultrametamorphism and metamorphic anatexis.     

对2005年盛夏十堰市一次连续强降水天气过程的分析

使用2005年8月14～23日各层(850、700、500 hPa等)天气图资料,以及有关物理量场资料、雷达回波资料和卫星云图资料,采取天气诊断分析方法,对2005年盛夏十堰市一次连续强降水天气过程进行了分析。结果表明:此次过程是在西太平洋副热带高压、"珊瑚"台风、东南急流、南支低槽、中低层低涡切变线等系统共同影响下形成的;贝加尔湖低槽持续分裂冷空气与副热带高压边缘暖湿气流对峙是该过程能够维持的基本条件;短带状强回波与新生的强对流窄回波带相叠加并维持较长时间,中-β尺度云团在本地发展为中-α尺度云团且受地形作用维持近5 h,使得灾情更趋严重。