A FUMIGATION DIFFUSION MODEL DURING THE MOUNTAIN-VALLEY WIND SHIFT PERIOD

The fumigation during the mountain-valley wind shift has been first identified as a special type of pol-lutant diffusion using the monitoring measurements of Dukou,Southwest Sichuan,China.Such a pheno-menon occurs frequently all year around but summer,particularly in winter months.A new model for thefumigation during the mountain-valley wind shift period is developed that allows satisfactory explanation ofthe fact.Analyses indicate that the model can more accurately predict not only the high concentration ofPollutants but the time and locality of the occurrence as well.The ground concentration of SO_2 during fumigation is several times up to over a decade higher thanthe daily mean for the whole region,one of the main contamination processes that affect the air quality ofthe city.The medel analyses provide a basis for more effective prediction of the quality and precautionstudy against the disaster.     

Late quaternary monsoon patterns on the Loess Plateau of China

China's Loess Plateau was formed under special conditions. The tectonic movement, topographical characteristics, and monsoon patterns combined to create a favourable environment for the accumulation of thick loessic deposits. The Loess Plateau itself is part of the ‘Monsoon Triangle’ of China, a region very susceptible to climatic changes. Throughout the Upper Pleistocene the palaeoenvironment on the Loess Plateau alternated from steppe, to deciduous forest and coniferous forest, in response to shifts in the atmospheric circulation. Three monsoon patterns appear to be indicated: (1) a full glacial monsoon pattern (18000–15000 yr BP) which induced a cold and dry climate favouring loess accumulation in steppe conditions; (2) an interglacial monsoon pattern (last interglacial and Holocene) in which a warm humid climate prevailed with deciduous forests, leaving palaeosols interbedded within the loess sequence; and (3) a transitional or interstadial monsoon pattern (50 000–23 000 yr BP) in which the climate was cold and humid in the Loess Plateau, encouraging the development of coniferous forest.     

岩石压剪性断裂特性及Ⅰ—Ⅱ型复合断裂判据

本文系统阐述了岩石压剪性断裂的特性,认为金属断裂力学复合断裂判据基本上不适用于压剪状态下的岩石斯裂;在此基础上,提出了新的岩石压剪性断裂判据:2COSθ_0/2(cosθ_0-1)[(1+1/f~2)~(1/2)-1]K_Ⅰ+[(sin θ_0/2-3sin 3θ_0/2)(1+1/f~2)~1/2+4sin θ_0/2]K_Ⅱ=4K_(Ⅰc),推导了起始断裂角ψ_0,说明了实验验证结果,指出了该判据在工程地质领域中的应用途径。     

多层递推平稳模型

通过对小概率事件历史样本作多层递推迭代，逐次改变引入样本数求取权函数，建立一种平稳统计模式。模式信息容量大，收敛快，克服了常规统计模式的局限性，在灾害性天气客观预报模型应用中取得了明显效果。     

华南变质基底的组成、边界与构造演化（研究综述）

本文据作者调查并综合有关资料，就华南变质基底的组成结构、边界性质、构造型式及演化过程作了较全面阐述；就板溪群是否为构造混杂岩，及其所代表的地质体性质作了深入分析和讨论，作者认为：华南可能存在晚太古－早元古统一变质基底，中元古末至印支期为板块活动期，印支期后，由于受太平洋板块作用影响而进入新的构造活动期。     

华南湘赣粤地区红层残积红土的工程地质研究

通过对红层残积红土的粒度成分、矿物成分、化学成分、物理化学特性、宏观结构、微观结构特征的全面系统分析，揭示红层残积红土不仅经历了物理风化作用，而且经受过红土化作用，具有红土的一般特点，是一种强度稍高，压缩性中等，含较多游离氧化物的超固结土。最后对红层残积红土的工程地质评价提出建议，认为其特性与母岩有关，砂砾岩、砂岩残积红土接近花岗岩残积红土；粉砂岩、泥岩残积红土接近红粘土，并对地基承载力和变形等问题提出具体的评价意见。     

非洲旅游业发展与布局研究

本文在分析非洲旅游资源和旅游业状况的基础上，对大力开展观光旅游、积极发展休疗型旅游、努力开拓专题旅游等问题进行了探讨。     

皖苏鲁新生代玄武岩的Sr-Nd 同位素组成及其含义

皖苏鲁新生代碱性玄武岩34个样品的Sr、Nd同位素组成，总的变化范围为ε°CHUR（Nd）=-4.5-6.9，ε°CHUR（Sr）=-20.4-33.1。分布在大洋玄武岩的Sr-Nd同位素组成范围内。其中江苏省六合一仪征、山东省蓬莱、栖霞和临朐等地区玄武岩同位素组成与PREMA型地幔端元相似，皖东嘉山-来安地区玄武岩具有EMI型地幔端元特征。前者来源于软流圈或更深部的地幔部分，后者来源于不均一的岩石圈地幔部分。来源于较流圈和岩石圈地幔的熔体互相作用决定了皖苏鲁新生代玄武岩 Sr-Nd 同位素地球化学特征。     

四川盆地紫色土温度状况的确定

以气象资料为基础，为土壤系统分类的需要，估计了四川盆地紫色土的温度状况，采用逐步回归方法，从与土温相关的１０项气象因素中，筛选出６项主要影响因素。根据本区土层浅薄的特点，建立了不同深度土层的土温计算方程。计算结果表明，按土壤系统分类的土温状况诊断标准，本区拥有热性土壤温度状况。     

澜沧江中下游斜坡稳定性评价预测的理论与方法探讨

本文以澜沧江下游流域边坡稳定性评价为实例，对模糊评判模型的应用问题和处理技术进行了论述。认为该模型简便实用、效果稳健、适应性强，是边坡稳定性评价工作中适宜推广的一个实用模型。此外，文中还提出了用于模糊评判模型的信息检验法，讨论了这一方法在遴选有效评价因子和优化模型效能中的作用。