This paper deals with the sources and harmfulness of environmental radon,analyses the geological background of radon in the urban district of Beijing and some basic measures for preventing and reduciang radon,and emphatically points out that indoor radon comes mainy from foundation rock and soil.

Based on recent English literature,this paper has summed up the present state and development of important gravimeters in the world,described a new type digital supergravimeter,and a new designing idea for gravimeter,viz. the application of absolute scale to the measurement of relative gravity.

Using soil magnetic susceptibility combined with geochemical,seismic and remote-sensing data,the authors made an integrated study of large-area oil-and-gas exploration in the desert region of western Inner Mongolia.The results show that the soil magnetic susceptibility anomalies are similar to hydrocarbon anomalies in distribution trend,both controlled by structure.Based on analytical results of magnetic susceptibility anomalies and magnetic mineral content in two oil-and-gas bearing local structures,it is held that the magnetic susceptibility anomalies result genetically from overall effects of secondary magnetic materials at the oil and gas bearing structural positions.Therefore,the application of this technique to the oil and gas exploration can only serve as an indirect indicator of the hydrocarbon alteration anomaly.

Based on fairly systematic observational data, the authors probed into dynamic variations of slow-released, rapid available and water soluble potash constituents in the rock-soil environment. The results show that the seasonal dynamic variation of slow-release potash constituents will condition that of the rapid available and water soluble potash constituents, with the variation range of the last two sorts of constituents larger than that of the first sort.Such dynamic variations are also influenced by soil types and soil depths.

On the basis of the principle of tri-frequency IP relative phase method,this paper expounds spatial characteristics of relative phase anomalies and points out indicators of anomalies related to mineralization,which are evidenced with known geological sections.

Using the theory of gray system, the authors analysed the data of oil and gas geochemical exploration, which reflect to some extent the oil and gas distribution regularity of the working district.The gray associationrprediction is a new technique for delineating oil and gas geochemical anomalies, which can raise the accuracy of trapping and prediction of oil and gas.

This paper sums up characteristics of Au anomalies within Tertiary red clastic beds in a certain area of Qinghai Province,and points out that Au anomalies mainly exist in the middle part of the Tertiary strata, that anomalies are most strong in stream sediments, and that Au anomalies result from secondary enrichment of Au.

This paper probes into the method and technique of applying airborne electromagnetic method to the exploration of shallow fresh water.To meet the water-searching demand,the authors compiled the tri-frequency standard deviation anomaly map with the reservation of regional field, and studied the transgressive boundary and transgressive degree of this area.29 fresh water prospect areas were delineated in the salt water region,with analysis and evaluation made for these prospect areas.

Exemplified by the application of shallow seismic reflected wave technique to the exploration of Haicang Bridge in Xiamen, this paper makes a preliminary discussion on various aspects of the application of shallow seismic reflected wave technique to the exploration of bridge site in water area.

The accurate displacement expression of Rayleigh wave, stimulated by a point source, on the surface of the half space,is deduced by the advanced Cagniard-Dehoop method. The expression in the previous literature can only calculate the displacement of a surface point. The wavefield of Rayleigh wave by the stable and transient source is also described.

BP network has been extensively applied.Nevertheless,under the condition of numerous learning samples and complicated input-output mapping relationship,the learning speed is rather low.Based on analysing characteristics of error curved surface of the network,the authors have advanced the rapid BP algorithm,which can greatly raise the learning speed.

Based on model experiment and practical application of magnetic method for detection of underground cultural relics,this paper systematically describes the mechanism,technique,character and effects of applying magnetic method to the detection of underground cultural relics.From survey through data processing to interpretation of achievements,it probes step by step into the working method,technological features,anomaly regularity and means for inference and interpretation of magnetic archaeology.With practical examples,the paper recommends an oprable and popularizable working system,emphatically deals with the merits and prospects of magnetic archaeology,and points out the content and direction of further research work.

In Shanghai area, borehole injection piles are used in large quantities for construction foundation in soft soil strata. The reinforcement cage for each injection pile consists of several parts linked together through welding. After the completion of the borehole injection pile construction, the inspection of the length of the reinforcement cage and the examination of welding quality constitute a very difficult problem. This paper recounts the technology and effects of applying high precision foundation pile diagnostic device and geological radar to the inspection of the length of reinforcement cage for the borehole injection pile.

Based on forward method,this paper recommends a new technique for 2.5 dimensional resistivity imagery,which can help to save calculation time.The imaging iterative procedure is quite stable,and can hence complete imaging for extensively existent media of high electric contrast degree,thus raising the practicability of the resistivity tomographic imaging technology.

Hydrocarbons in the rock were adsorbed by adsorption wires and then released into the gas chromatography instrument at the Curie temprature to be analysed. The components of the sample wre affirmed by Retention Index and chromatography mass. The quantitative data were handled with computer. The distributed figure of total hydrocarbons and the triangular figure can effectively judge the oil producing capability of strata and the degree of evolution.

Aimed at solving the problem of "the more the superimpostion,the lower the quality of seismic record" which was encountered during the seismic logging in Shanghai,the author used the method of gradual reduction of electrospark charging vaotage, which greatly raised the quality of seismic record and thus met the engineering demand.This paper also recommends two easy and practicable methods for overcoming the trouble.