Sedimentary cycles of trace elements in Salawusu River Valley since 150 ka BP

The paper makes some analyses on 11 trace elements in the Milanggouwan stratigraphical section in the Salawusu River valley, which is regarded as a prototype geology-palaeoclimate record since 150 ka BP. The results show that the content and variation of trace elements has experienced remarkably regular changes in the pace with coarse and fine sedimentary cycles of palaeo-aeolian sands to its overlying fluvio-lacustrine facies or/and palaeosols. The trace elements with chemical properties of relatively active (V, Sr, Cu, Ni, As) and relatively stable (P, Pb, Rb, Mn, Nb, Zr) are a manifestation of the corresponding 27 changeable cycles between peak and valley values, appearing a multi-fiuctuational process line of relative gathering and migration since then. The low numerical value distribution of these two types of trace elements in the aeolian sand facies represents erosion and accumulation under wind force during the cold-dry climate. Whereas their enrichments in both fluvio-lacustrine facies and palaeosols are related to the valley’s special low-lying physiognomic position between the Ordos Plateau and the Loess Plateau under the warm and humid climate conditions. The above relatively migrated and gathered change of the trace elements is the result of 27 climatic cycles of cold-dry and warm-humid, which is probably caused by repeated alternations of winter monsoon and summer monsoon in the Mu Us Sandy Land influenced by the climate vicissitudes in northern hemisphere during glacial and interglacial periods since 150 ka BP.     

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater’s economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da’an in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.     

新疆城市化过程及机制分析

城市人则城市化研究的核心问题。在分析新疆城市化现状特征的基础上，围绕新疆城市发展的阶段和过程，采用多因素的灰色关联分析和比较分析等手段，对新疆1978－2000年间城市化发展过程进行分析和探讨，寻求并探索新疆城市化发展的特征、水平和演化机制。研究结果发现各因素与城市化的关联度不仅在横向上存在着指标间的差异，在纵向上显示出1990－2000间各指标与城市化的相关性明显高于1978－1989年间，部分指标与城市化关系发生了负向变化。表明近20多年来新疆城市化稳定发展，城市化系统条件（农村和城市的控制性次系统及整个社会经济文化）有一定的提高，体现了系统各因素与城市化发展的同向性以及区域发展的合理趋势，但整体薄弱的社会经济基础是新疆城市化落后的根本原因，产业结构升级转换仍将是新疆城市化的主要动力。     

粘性泥石流残留层的形成及减阻作用--以云南蒋家沟泥石流为例

通过对云南蒋家沟粘性泥石流的野外观测 ,讨论了粘性泥石流残留层的定义特征 ,在大量实测数据基础上 ,分析了残留层易形成时段的特性 ;分别对一次泥石流过程、若干阵泥石流和一阵泥石流残留层的变化进行了相关分析 ;最后用观测数据分析了泥石流残留层的减阻作用     

川藏公路拉月滑坡的块状破坏特征

拉月滑坡位于东久河左岸，为典型的高位岩质滑坡。1967—08—29拉月一带山体突然发生特大型滑坡，体积超过千万立方米，是川藏公路线上著名的“拉月大塌方”灾害。文章应用块状岩体稳定性分析方法，对同结构岩石块体相互嵌合、形成具不同稳定状况的的岩体结构、控制了滑坡的发生的特点进行了分析，证明该方法判别岩质滑坡的稳定性是非常有效的。岩质滑坡在西藏与西南地区都十分普遍，因此，通过对拉月滑坡块状破坏过程的分析，对其它岩质滑坡的稳定性判别具有很好的借鉴作用。     

209国道许家湾滑坡的成因及治理对策

结合许家湾滑坡灾害点的地质背景资料和现场勘察结果，从滑坡区的地貌、区域地质构造、地层岩性、土壤特性、水文地质特征以及人类工程活动等方面分析滑坡成因机制。指出同向多层次结构的边坡类型、山高坡陡及地表水汇集走廊的地貌特征、发育多组密集节理的区域地质构造、软硬互层的地层岩性、土体的残余强度特性等是滑坡形成的内因；而人为削坡、强降雨和破坏植被营造水耕梯田等人类活动所造成的流水浸蚀，是滑坡形成的诱发空子。基于滑坡稳定性的定量计算，确定了采用抗滑挡土墙、格构式地梁和垫梁组成抗滑系统，并布置了由树枝笼渗沟构成的排水系统等工程治理措施。现场监测结果表明滑坡治理措施卓有成效。     

胶茶人工群落在改善山地土壤生态环境上的作用

经过多年的实践和研究结果表明，橡胶(Hevea brasiliensis)—茶树(Camellia sinensis)两层人工群落结构，比单一橡胶种植模式有着明显的改善山地土壤生态环境的特点。胶—茶人工群落对减少水土流失，改善土壤微生物状况，增强土壤地表呼吸强度，促进团聚体形成和提高土壤肥力以及增加单产等方面，均有显著的效果。因此，胶—茶人工群落为合理利用我国西部热带山地资源，开辟了一条新的经营种植模式。     

Dynamic processes of a simple linear dune—a study in the Taklimakan Sand Sea, China

Samples of dune sands, surveys of the morphology and field measurements of wind velocity and direction of a simple linear dune in Taklimakan Sand Sea show that the airflow and sand flux vary with the change of wind direction on the dune surface. Decrease of the airflow stress on the lee flank does not result in much decrease of the sand flux because of the low threshold shear velocities and the airflow conditions. There are no significant relations between the sand flux on the lee flank and the angle of incidence of the airflow. The low threshold shear velocities and the maintenance of the sand flux at the lee flank are the main mechanisms keeping the linear shape of the dunes. Measurements of the sand flux shows that it reaches a maximum on the crest of the dune. The grain size of the transported sands has some differences compared to that of the dune surface. The sands transported are finer than that on the dune surface, but better sorted under the influence of the medium to low wind activity. The field experiment results exhibit that it is possible for the dunes to be shaped as linear dunes during the processes of accumulation and elongation.     

从江县翁浪金矿床容矿岩石与围岩蚀变及其找矿标志

文章简单介绍了构造蚀变岩型金矿翁浪金矿床的容矿岩石和围岩蚀变特征，指出该类矿床的找矿标志，对进一步寻找此类矿床有一定的意义。     

松潘-甘孜带：是弧前增生还是弧后消减?

根据多年在该区工作实践，认为松潘—甘孜造山带前身的巴颜喀拉盆地是羌塘—他念他翁晚古生代前缘弧之后的一系列多岛弧—盆系的一个大型弧后盆地。三叠纪时，围限此“三角形”盆地三条边缘的构造动力学作用方式具有不同的特征。其东侧为扬子西缘被动大陆边缘(D—T2)，中三叠晚期(拉丁期)转化为与华北和羌塘陆块有关的前陆盆地(T2—T3)，由于扬子陆块向西双向斜向俯冲作用，在其北侧和南侧边缘形成南昆仑和可可西里—甘孜—理塘俯冲消减杂岩。重建的地层层序和沉积地质特征显示巴颜喀拉盆地主体三叠系复理石沉积是周缘前陆盆地。