伊朗卡尔赫水电站坝址松散砾岩钻探工艺          下载免费PDF全文

路殿忠 《探矿工程》1994,(3):30-31

在伊朗卡尔赫水电站坝址工程勘察中，采用金刚石双管单动钻具和ＳＭ胶冲洗液进行取样钻探，用清水钻进压水试验，由于钻探工艺合理，钻探质量均达到了设计要求。  相似文献   

NOAA WP-3D instrumentation and flight operations on AGASP-II     

R. C. Schnell  T. B. Watson  B. A. Bodhaine 《Journal of Atmospheric Chemistry》1989,9(1-3):3-16

The second Arctic Gas and Aerosol Sampling Program (AGASP-II) was conducted across the non-Soviet Arctic in March and April 1986, to study the aerosol, gaseous, chemical, and optical properties of Arctic haze. One component of the program was supported with an instrumented NOAA WP-3D atmospheric research aircraft. Measurements of wind, temperature, ozone, water vapor, condensation nucleus concentration, and aerosol scattering extinction coefficient were used to determine the locations and properties of haze layers. The first three NOAA WP-3D research flights were conducted north of Barrow, Alaska, and over the Beaufort Sea northeast of Barter Island, Alaska. The next three sampled conditions in the high Arctic near Alert, Northwest Territories, Canada. All basic meteorological, gas, and aerosol systems are described. The WP-3D flight tracks and operations are presented.  相似文献   

航摄底片信息容量的确定     

宣家斌  S.A.Hempenius 《武汉大学学报(信息科学版)》1986,(4)

为了定量地分析航摄底片的信息容量,本文在影象数字化的基础上,从理论上分析信息容量的估算公式,监重点研究用“比特分割”的方法确定其有效的比特数。  相似文献   

The tropospheric distribution of formaldehyde during TROPOZ II     

D. W. Arlander  D. Brüning  U. Schmidt  D. H. Ehhalt 《Journal of Atmospheric Chemistry》1995,22(3):251-269

A series of 149 measurements of the HCHO mixing ratio were made between 0 and 10 km altitude and 70° N to 60° S latitude during TROPOZ II. The data show a vertical decrease of the HCHO mixing ratio with altitude at all latitudes and a broad latitudinal maximum in the HCHO mixing ratio between 30° N and 30° S at all altitudes. The measured mixing ratios of HCHO are considerably higher than those expected from CH₄ oxidation alone, but agree broadly with the average latitude by altitude distribution of HCHO derived by a 2D model including emissions of C₁–C₇ hydrocarbons. A number of the regional scale deviations of the measured HCHO distribution from the average modelled one can be explained in terms of the local wind field.  相似文献   

Tomographic determination of 3-D crustal structure — Joint inversion of explosion and earthquake data     

Xian-Kang Zhang  Zhuo-Xin Yang  Yu-Chun Yang  Jian Yang  Jian-Li Song  Ping Zhao 《地震学报(英文版)》1995,8(4):519-529

In this paper, the theory and method, obtaining the tomographic determination of three-dimensional velocity structure of the crust by use of the joint inversion of explosion and earthquake data, are given. The velocity distribution of the crust is regarded as a continuous function of the spatial coordinates without parametrization of the velocity model ahead, so that the inversion solution would not be influenced by different parametrization procedures. The expressions of integration kernels, which relates the two kinds of data sets, are also given. The authors have processed the observed data in Tangshan earthquake region by the method proposed in this paper, and obtained the tomographic results of the middle and upper crust structures in this region. The comparison of these results with the result obtained only by the explosion data, has also been made.  相似文献   

Transport and sedimentation of particles in a fluid flow     

J. Gani  P. Todorovic 《Stochastic Environmental Research and Risk Assessment (SERRA)》1987,1(3):209-216

A simple two-dimensional random walk model is developed for the motion of a particle in a fluid flow. Some earlier results for the persistent injection of particles into the flow are extended, and the distribution of the maximum number of particles in suspension over the period (0,t) is derived.  相似文献   

Efficiency of kriging estimation for square, triangular, and hexagonal grids   总被引：8，自引：0，他引：8  

Evangelos A. Yfantis  George T. Flatman  Joseph V. Behar 《Mathematical Geology》1987,19(3):183-205

Although several researchers have pointed out some advantages and disadvantages of various soil sampling designs in the presence of spatial autocorrelation, a more detailed study is presented herein which examines the geometrical relationship of three sampling designs, namely the square, the equilateral triangle, and the regular hexagon. Both advantages and disadvantages exist in the use of these designs with respect to estimation of the semivariogram and their effect on the mean square error or variance of error. This research could be used to design optimal sampling strategies; it is based on the theory of regionalized variables, in which the intrinsic hypothesis is satisfied. Among alternative designs, an equilateral triangle design gives the most reliable estimate of the semivariogram. It also gives the minimum maximum mean square error of point estimation of the concentration over the other two designs for the same number of measurements when the nugget effect is small relative to the variance. If the nugget effect is large (.90 ² or more), and the linear sampling density is >0.85r where r is the range, the hexagonal design is best. This study computes and compares the maximum mean square error for each of these designs.  相似文献   

Automatic sampling of stream water during storm events in small remote catchments     

R. P. Martin  R. E. White 《地球表面变化过程与地形》1982,7(1):53-61

In order to study the relationship between water composition and stream flow rate, it is desirable to sample at a frequency related to flow rate, especially during storm events. In a rural catchment of 18 ha near Oxford, the rate of rainfall was found to be linearly related to discharge on the rising limb of the stream hydrograph. A sampling system was therefore designed in which electrical pulses from a tipping-bucket raingauge were used to initiate and control the action of an automatic water sampler. A threshold rainfall intensity is set above which sampling commences. Sampling then continues at regular increments of rainfall until the intensity drops below the threshold, after which sampling occurs at regular intervals during the period that the stream flow reverts to normal. The CMOS electrical circuits which control the sampling also operate a cassette tape recorder which records the time of each tip of the raingauge and operation of the sampler. Since the sytem is designed to impose very little additional load on the battery which powers the water sampler, and can operate unattended for at least a fortnight, it is ideal for use in small, remote catchments. The system has been extended to include measurements of water temperature and could provide other measurements as well.  相似文献   

高烈度区连续梁桥的减震设计方法研究   总被引：2，自引：1，他引：2  

方海  李升玉  王曙光  刘伟庆 《地震工程与工程振动》2005,25(6):178-182

本文以高烈度区的某三跨连续梁桥为例，分别采用基础隔震和消能减震两种措施进行结构的减震分析；针对隔震结构减震效果好但主梁位移过大的特点，提出了在采用铅芯橡胶隔震支座的同时设置粘滞阻尼器的减震方案，其非线性时程分析结果表明，该方案能有效地降低结构的地震反应，可供工程实践参考。  相似文献   

王艳，廖明生，李德仁等.利用长时间序列相干目标获取地面沉降场.地球物理学报，2007          下载免费PDF全文

王艳  廖明生  李德仁  魏子新  方正 《地球物理学报》2007,50(2)

方法，相干目标分析是利用时间序列多景影像获取地表稳定反射体——高相干点目标的新方法.实验区选择上海市主城区约100 km2 区域，InSAR的实验数据采用覆盖1992～2000年间的25景ERS-1/2的单视复影像.在无先验沉降场模型的情况下，实验结果显示该实验区的地面沉降场在时间范围上跨越8年，平均观测时间采样率约为4个月，垂直形变精度优于5 mm，满足我国对城市地面沉降形变观测的要求.研究结果表明该方法可以用于今后大时间/空间尺度上的高精度地表形变观测.  相似文献