堤防防渗芯墙质量检测技术及效果

简要阐述了长江堤防检测方法产生的历史背景和现状,具体介绍了CSAMT法的基本原理、“K”剖面法资料处理的计算公式以及CSAMT法在堤防防渗芯墙质量检测中的试验效果及应用效果,并指出在工作中应该注意的问题。     

Simulation of land use change using GIS-based stochastic model: the case study of <Emphasis Type="Italic">Shiqian</Emphasis> County,Southwestern China

This paper presents the GIS-based stochastic model and its application to simulate land use change in Shiqian County, Southwestern China. Transition probability of land use change with biophysical factors such as elevation, slope, distance to stream, distance to road and adjacent cells with the same land use are calculated and integrated into this model. Then the model simulated 2001 land use pattern based on 1988 land use pattern and the results are satisfactory. Finally, three different land use scenarios are simulated using this model. This study provides a new tool to predict land use pattern.     

Gps,gis and geomorphological field work

This paper introduces the Global Positioning System (GPS) and considers its role as a technique for use in geomorphological field work. Although valuable on its own, it is apparent that the utility of GPS in geomorphology is enhanced when used alongside Geographical Information Systems (GIS) technology in the field. This paper reviews GPS, considering what it is, the methods available and their relative accuracies, the potential and problems of the technology and its relationship with GIS. Particular attention is given to the application of GPS in geomorphological and related case studies. Examples are presented of the successful use of GPS and GIS to study hydrology and snow patch regime from the recent GeoAltai expedition to Southern Siberia.     

The Suction Side Sample Catcher in Ground Water Quality Sampling

A suction side sample collector (SSSC) is a contrivance installed hydraulically ahead of the intake port of a pumping device. This paper describes construction and operational details of SSSCs fitted to a submersible pump with packer for use in a 6-inch cased borehole, an air lift pump with packer for use in a 1-inch or 2.5-inch cased borehole, a bladder pump for use in a casing of 2-inch or greater diameter, and a jet pump with packer for use in a 2-inch cased borehole.
Each form of SSSC has been thoroughly tested in ground water quality sampling for volatile organic chemicals. Comparative data for samples collected with the SSSCs and conventional sample collecting gear are presented. The SSSC is demonstrated to be superior to other methods of collecting volatile organic chemical samples owing to its freedom from contamination by the pump delivery line and to its mode of collecting the sample from a position in the well remote from disturbance by the pumping technique.
SSSCs are conveniently decontaminated, easily transported, and can be used to deliver samples to the laboratory while still at formation pressure. The air-lift pumps, described in this paper for use with SSSCs in 1- and 2.5-inch casings, have pumping capacities greater than obtained by other methods that can operate in these small casings. Discharge rates of up to 2 gpm are routinely achieved with the 1-inch model and higher rates are common With the 2.5-inch model. The use of packers with these pumps reduces the time needed to replace the water in the casing with fresh water from the formation.     

Conjunctive use of surface and groundwater in central Asia area: a case study of the Tailan River Basin

Conjunctive use of surface and groundwater is an effective approach to relief water resources shortages and its uneven temporal and spatial distribution in arid inland regions of central Asia. In this paper, 16 characteristic factors of water resources and related systems which are sensitive to different types of conjunctive use were selected in order to develop an index system for evaluation impact of conjunctive use, based on the fundamental types of water resources conjunctive use in inland basins. In an attempt to address the issue of spring drought and summer floods in Tailan River Basin in Xinjiang, three scenarios of conjunctive use of surface water and groundwater, well-canal combination, piedmont reservoirs and groundwater reservoirs were investigated. The utilization of water resources and the response of its related systems were evaluated and analyzed quantitatively using the groundwater numerical simulation model (Visual MODFLOW). Furthermore, the impacts of conjunctive use were assessed using the method of multi-level fuzzy comprehensive assessment. The results show that the scheme of combination of Laolongkou piedmont reservoir regulation-groundwater development, is the best in terms of the evaluation of water conjunctive use effects, followed by the well-canal combination. The comprehensive effect of well-canal combination along with groundwater reservoir wouldn’t be better than the former both.     

The use of bioestimation—a new method for the control of water self-purification

Examples are given of the application of bioestimation??a conceptually new hydrobiological method used to control the process of water quality formation. This paper is the continuation of the paper ??Bioestimation: A New Method for the Control of Water Self-Purification Process and Its Comparison with Bioindication??. The experience in the use of bioestimation in water bodies with different use type, size, salinity, flowage, and geographic position confirmed its universal character, information value, promptness, and the possibility to limit the volume of sample to be sent to 10?C20 cm³, thus simplifying the field works. Each significant factor, which affects the self-purification process, is identified independently, since the bioestimators reflecting it are biotically independent; their number varies depending only on changes in the environmental factors that are external with respect to the community of environmental factors. Bioestimation shows prognostic properties, since it makes it possible to prevent water quality deterioration and to restore the normal course of water self-purification at the stage of its quality formation. The use of bioestimation will extend the positive anthropogenic impact on water bodies.     

Atmospheric and glow images from the Shuttle

The use of simple photographic cameras on early Shuttle missions allowed spacecraft glow to be clearly identified, and its potential for the contamination of weak atmospheric emissions to be estimated. Since those early flights the equipment has been extensively modified so that it is now possible to obtain images with a spectral resolution of 0.1 nm. The early Shuttle glow observations are reviewed and the use of spatially scanned filters to obtain spectral results is described. These glow measurements are discussed in terms of some current ideas for vehicle induced glows and it is suggested that the glow intensity may be controlled by the temperature of the glowing surface. An example of an atmospheric image obtained with the interference filter camera is presented and the limitations in the use of such images are discussed.     

IRIS DMC的数据服务

介绍了IRISDMC的数据来源、数据服务内容和数据请求工具,这对于较好地使用其数据资源及做好中国的地震数据服务工作有一定的意义。     

关千ΔT磁异常的解释

本文对于二度问题证明了总磁場强度△T与垂直磁場强度Z的一般表达式具有相同的形式,因此可以把△T异常曲线看成Z异常曲线,利用复变函数理论中的柯西-黎曼条件我们就可根据△T异常曲线计算出与H异常曲线相当的所谓△T的“负共轭调和函数”△T,文中指出了同时利用△T及其原函数△T将有助于磁测资料的解释工作,还举出了两个应用的例子:1)根据△T与△T计算二度体的磁矩及其倾角;2)利用观测水平上的△T及△T值将△T向下解析延拓。     

用积分与迭代方法反演磁性地质体的总磁矩及其中心位置

本文研究了利用二维磁异常和一维垂向导数异常的矩的积分,计算磁性体总磁矩及其中心位置的迭代方法。在计算过程中,只要给出磁矩中心位置坐标的初值,就能计算出总磁矩及其中心位置。     

Farmers’ awareness and perception of Lake Ziway (Ethiopia) and its watershed management

The article examines how heads of farmers’ households perceive the socioeconomic benefits of Lake Ziway (Ethiopia), the causes of its current degradation, and the state of land and water use management in its watershed. The investigation was based on in-depth empirical field work including a survey with 635 heads of smallholder farmers’ households via interview using semi-structured questionnaires. Further, water abstraction was estimated from three districts that border with the lake. Respondents believe that Lake Ziway provides a number of individual and collective benefits for local communities, private companies and public institution. They stated, however, that the lake is under pressure from the floriculture industry and other investment projects, high population growth and subsequent expansion of settlements and irrigation farms, high applications of agrochemicals, soil erosion, uncontrolled water abstraction, and deforestation in the watershed. The respondents further believe that these activities are degrading the lake water quality, shrinking its water volume and decreasing its fish population. After examining government’s efforts to address these activities, the majority of respondents believe that the government role in the whole watershed is weak. This study contributes to better understand the local socio-ecological coherences and the problems Lake Ziway and its watershed are facing. It also provides information regarding long-term sustainable land and water use planning strategies for the lake and management of its watershed, which could also be applied to other lakes in Ethiopia, and beyond.     

学习向量量化(LVQ)在地震和爆破识别中的应用

介绍了竞争神经网络和学习向量量化（LVQ）算法。此算法应用于对北京及周围地区地震和爆破的识别中，在对38个事件的应用中，得到的结果是，误识为3个，结果较好，说明在识别中是有效的。     

电阻率反演及其应用

针对大部分沉积岩具有层理结构,从其电性上来看,它们是由各种不同电阻率的地层组成的,这样的地层其电阻率呈现出各向异性。在对电阻率断面进行观测时,要在层状介质背景剖面的基础上,利用二维电阻率扰动反演方法,将背景场环境中的电性层结构进行掌控,并对敏感矩阵进行计算,通过实验得到良好的效果。     

Using the applied element method for modelling calcium silicate brick masonry subjected to in‐plane cyclic loading

The response of calcium silicate unreinforced masonry construction to horizontal cyclic loading has recently become the focus of experimental and numerical research, given its extensive use in some areas of the world that are now exposed to induced earthquakes (eg, north of the Netherlands). To assess the seismic behaviour of such construction, a relatively wide range of modelling methodologies are available, amongst which the discrete elements approach, which takes into account the intrinsic heterogeneity of a brick‐mortar assembly, can probably be deemed as the most appropriate computational procedure. On the other hand, however, since discrete elements numerical methods are based on a discontinuum domain, often they are not able to model every stage of the structural response adequately, and because of the high computational burden required, the analysis scale should be chosen carefully. The applied element method is a relatively recent addition to the discrete elements family, with a high potential for overcoming the aforementioned limitations or difficulties. Initially conceived to model blast events and concrete structures, its use in the earthquake engineering field is, of late, increasing noticeably. In this paper, the use of the applied element method to model the in‐plane cyclic response of calcium silicate masonry walls is discussed and scrutinised, also through the comparison with experimental results of in‐plane cyclic shear‐compression tests on unreinforced masonry walls.     

Crustal structure beneath Beijing and its surrounding regions derived from gravity data

In this paper we use gravity data to study fine crustal structure and seismogenic environment beneath Beijing and its surrounding regions.Multi-scale wavelet analysis method is applied to separating gravity fields.Logarithmic power spectrum method is also used to calculate depth of gravity field source.The results show that the crustal structure is very complicated beneath Beijing and its surrounding areas.The crustal density exhibits laterally inhomogeneous.There are three large scale tectonic zones in ...     

Integrated environmental management: The Dutch Governmental view

In the last 10 years concern for the economic and ecological value of the North Sea has increased. Many different users are putting increasing pressure on the resources of the North Sea and its adjacent estuaries. Its uses include shipping, fisheries, the oil and gas industry, mineral extraction, and—along its shores—recreation. The North Sea suffers pollution directly from some of these sources, but also indirectly from discharges from land, from rivers and from the atmosphere. The resilience of the North Sea ecosystem puts limits on the human use. These limits have in a number of cases been exceeded. It is necessary to define and assess the sustainable use of the North Sea ecosystem. The sustainable use may be defined as the long-term use of current and future potential while ensuring sustainable conservation of the ecological value of the North Sea and adjacent vulnerable water systems. Integrated environmental management for the North Sea implies that policy-makers assess all interests and resolve any conflicts which arise. This paper considers the problem of input of organic substances into the North Sea. It considers a target scenario of sustainable use and ecological health, in relation to what concentrations of organic substances are permissible. Secondly, it considers a target percentage reduction in current inputs. Thirdly, it is necessary to give the measures to be taken to deal with the major sources of the pollution, i.e. to define target groups. Finally, the paper gives examples of the statutory instruments available to implement the chosen policy.     

Ecohydrological change mechanism of a rainfed revegetation ecosystem at southeastern edge of Tengger desert,Northwest China

Study is made on a 45 km-long artificial ecosystem without irrigation in Tengger desert on the basis of long-term ecological monitoring and ecohydrological fundamentals.Changes in water allocation, utilization, cycle and balance patterns in more than 40-year evolution of the soil-plant system are analyzed. The formation of a drought horizon in shrub rhizosphere and its effect, ecohydrological function of the crust and its effect on the soil-plant system change are discussed. Driven by water self-regulation and water stress, the soil-plant system is going to develop towards the steppe desert to ensure more effective use and optimum collocation of water resource.     

大地电磁地震前兆初步分析系统

介绍了大地电磁(MT)地震前兆初步分析系统的建立及主要功能,运用该系统对2003年度祁连山地震带8个大地电磁复测点进行了MT多参量综合对比、变化幅度的计算及异常前兆判定,取得较好效果。     

E-Defense建设与相关研究

详细介绍了目前世界最大三维地震模拟振动台现代先进的技术性能与测控系统,以及E-De-fense别名与徽标寓意、建设背景与意义、设施组成与功能、运行组织与管理、服务与研究计划、已完成研究项目、成果公布与共享途径、利用形式与申请程序等若干引起关注的问题,并简述了日本大大特研究计划及其在E-Defense实施内容,同时提出了我们利用E-Defense开展相关研究的一点建议,以供我国基于E-Defense试验条件寻求与日本合作时参考。     

On disturbances in a piezoelectric layer permeated by a magnetic field

Summary The methods of transform calculus are made use of in finding the disturbances in a piezoelectric layer with an impulsive force at its free faces in presence of a magnetic field. The problem is solved for time dependent elastic compliance of the material of the layer.