氧化镍、二氧化钛高压相变及电导率压力效应

采用金刚石对顶砧压腔静高压技术，对氧化镍、二氧化钛在０-３２ＧＰａ压力范围内的电导率进行了测量．结果表明，电导率－压力关系曲线上的一些特征点与同一物质的高压相交点具有一致性．     

Anomalous induction across Europe

Summary Using real induction vector data, collected at 958 European observation sites, together with our data from the Bohemian Massif and the West Carpathians, we have generated a contour map of the transfer function TF1 (corresponding to transfer function A in Wiese's relation). Only the zero contour is retained and shown on the map. It clearly marks the main anomalous induction zones, related to internal structural inhomogeneities, across Europe.     

Research on earthquake prediction from geomagnetic pulsation

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Surface conductivity in rocks: a review

Electrical properties of rocks depend on composition (i.e. bulk properties of the constituents), micro structure (i.e. geometrical arrangement of the constituents) and interfacial effects. We consider here a rock as a three component system — grains, pores, and interfaces — in order to account for the observed behaviour. We review first the main results relative to DC. conductivity. Surface conductivity effects show up clearly in the case of shaly formations or at low salinities. Although Archies' law (1942) and Waxman and Smits model (1968) are widely used, a more physically based model is that of Johnson and Sen (1988). We review also the variable frequency conductivity (complex conductivity) data and models. The important effect in that case is the enhancement of the dielectric constant at low frequencies (Knight and Nur, 1987) which can be interpreted as a geometrical effect although electrochemical interactions may also play an important role at low frequencies, depending on the rock type.     

Upper mantle lateral heterogeneities and magnetotelluric daily variation data

We use telluric and magnetic data of the diurnal variation recorded in Europe, Australia and North America to study the magnetotelluric tensor in the 6h–24h period range. We use associate directions and we eliminate the effects of deviation of telluric currents. We thus obtain for each observatory reliable phases and apparent resistivity values representative of the neighbouring stratified substratum. It appears that the values obtained in the four European observatories (Saint-Maur, France; Ebro, Spain; Toledo, Spain; Nagycenk, Hungary) give similar results and that these results are different from those obtained either in Tucson (USA) or in Watheroo (Australia).Using Bostick transform we interpret these phase and apparent resistivity values in terms of conductivity of the upper mantle. We discuss then the conductivity heterogeneities in terms of change either in temperature, or partial melting or percentage of fluids of the upper mantle: at depths of about 300 km, the upper mantle appears to be 100 °C hotter under Australia than under Europe; the probable presence of fluids at depths about 100 km in the southwestern North America upper mantle appears to be responsible for the high observed conductivities. All these conductivity values are coherent with tomography results from Woodhouse and Dziewonsky: high (low) conductivities are cohernet with low (high)seismic wave velocities.     

论"单位涌水量就是导水系数"

单位涌水量是井抽水水位降深换算为1 m时的单井出水量;导水系数是含水层宽度为1 m时,地下水水力坡度为1时的单宽流量.二者之间从定义上看毫无关系,但它们的单位(m3/d·m)(m2/d)是相同的.笔者经过多年探讨和初步试验后发现,单位涌水量就是管井抽水所利用含水层的导水系数.     

A method to estimate hydraulic conductivity from bulk geochemical compositions

A new method has been developed to estimate the hydraulic conductivity in unconsolidated aquifers. The method uses bulk geochemical compositions correlated with hydraulic conductivities measured by pumping tests. The concept is based on a general rule that hydraulic conductivity is principally controlled by grain-size distribution and particle shape,both of which relate to mineralogical composition. Using a MINLITH algorithm, normative mineralogical compositions can be derived from bulk geochemical compositions economically and expediently, and then correlated to the hydraulic conductivity determined by pumping tests in the field. In this study, 202 sediment samples from nine unconsolidated aquifers were analyzed by X-ray fluorescence. Although hydraulic conductivity does not show a definite relationship with geochemical compositions, it does demonstrate a linear logarithmic equation to the content of normative earthy minerals. However, linear regressed equations should not be applied to aquifers composed of medium to coarse sand and gravel sizes due to interference from lithic fragments. In addition, this equation tends to overestimate hydraulic conductivity possibly because the effect of compaction is ignored in this study.     

Numerical simulation of groundwater flowing to horizontal seepage wells under a river

A horizontal seepage well, consisting of an interconnected vertical well, galleries, chambers and small-diameter radiating bores, is used to acquire relatively clean water that has been filtered through natural alluvial deposits in a riverbed. It has wide application, especially in arid and semi-arid areas. The lack of calculation formulae or models for horizontal seepage wells, up until now, has resulted in several false applications. Based on the analysis of groundwater flow characteristics, it has been concluded that several flow regimes coexist and hydraulic head loss exists in the horizontal seepage well. To avoid the difficulty of confirming the flux or head distribution in such a complex system, the model boundary of the whole horizontal seepage well has been moved to that of just the vertical well, and the well-aquifer system was treated as a heterogeneous medium, where the horizontal seepage well itself is a highly permeability medium. A mathematical model has been developed, based on the coupled seepage-pipe flow, by the introduction of equivalent hydraulic conductivity according to different flow regimes. Then a three-dimensional finite difference numerical model, based on the mathematical model, was developed and applied to a horizontal seepage well in China. The numerical model verified the groundwater flow characteristics of the horizontal seepage well. An erratum to this article can be found at     

Fhe application of electromagnetic-induction on the measurement of sea ice thickness in the Antarctic

As an important component of the cryosphere, sea ice is very sensitive to climate change. The study of sea ice physics needs accurate sea ice thickness. This paper presents an electromagnetic induction （EM） technique which can be used to measure the sea ice thickness distribution efficiently and its successful application in the Antarctic Neila Fjord. Based on the electrical properties of sea ice and seawater and the application of electromagnetic field theory, this technique can accurately detect the distance between the EM instrument and the ice/water interface to measure the sea ice thickness. Analyzing the apparent conductivity data obtained by the electromagnetic induction technique and drill-hole measurements at same location allows the construction of a transform equation for the apparent conductivity and sea ice thickness. The verification of the calculated sea ice thickness using this equation indicates that the electromagnetic induction technique is able to determine reliable sea ice thickness with an average relative error of only 5.5%. The ice thickness profiles show the sea ice distribution in Neila Fjord is basically level with a thickness of 0.8 - 1.4 m.     

ACTIVE system for monitoring volcanic activity: A case study of the Izu-Oshima Volcano,Central Japan

A system is proposed for the monitoring of changes in the underground structure of an active volcano over time by applying a transient electromagnetic method. The monitoring system is named ACTIVE, which stands for Array of Controlled Transient-electromagnetics for Imaging Volcano Edifice. The system consists of a transmitter dipole used to generate a controlled transient electromagnetic (EM) field and an array of receivers used to measure the vertical component of the transient magnetic field at various distances, with automatic operation of both units. In order to verify the performance of the proposed system, numerical and field experiments were carried out by application of the system to the Izu-Oshima volcano, where a remarkable change in the apparent DC resistivity over time had been detected in association with the eruption in 1986.