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1.
The purpose of the present work is to study the hydrodynamic aspects in the Mar Piccolo, a coastal basin located on the northern side of the Gulf of Taranto in the Ionian Sea (Italy), by means of mathematical modelling and field measurements. The latter were assessed during three surveys carried out in the spring–summer of 2002. Collected data have been utilized as input by the 3-D Princeton Ocean Model, which is a sigma coordinate, free surface ocean model which was developed in the late 1970s by Blumberg and Mellor. Simulations in baroclinic condition were forced by a homogeneous and stationary wind field, a simple tidal wave, a constant outflow and vertical stratification of temperature and salinity. A comparison was made between the mathematical modelling results and the field measurements collected during the surveys, in terms of velocity. It was observed that during small tides, when the wind effect prevails over the stratification effect, the best model results were obtained for the most superficial layer and that superficial patterns reproduced by the model are more sensitive to wind direction than to stratification. On the contrary, when the wind effect decreases or the thermohaline effect rises, best results occurred in deeper layers.  相似文献   

2.
The impact of lost circulation during rotary drilling near an existing monitoring well cluster was evaluated by periodic measurements of water levels and contaminant concentrations at the well cluster. Due to regulatory concerns, changes in water levels or VOC concentration in the well cluster during drilling would trigger monitoring well redevelopment. The borehole was drilled approximately 30 feet northeast of four nested monitoring wells that screen Devonian and Silurian carbonate bedrock at depths of 15, 60, 130, and 190 feet. Following complete circulation loss at depths of 177 and 1 S3 feet in the borehole, a rapid decrease in water levels was observed in the upper three monitoring wells. The water level in the well that was screened through the lost circulation zones increased slightly.
Decreasing water levels in formations located above the point of circulation loss appear to occur in response to a sudden decrease in borehole fluid pressure caused by the flow of drilling fluid into the formation. The relative contribution of contaminated formation water lo the borehole can be estimated by using the time-drawdown relationship and estimates of transmissivity. At the point of circulation loss, significant dilution of contaminant concentrations occurs from the loss of drilling fluid into the contaminated zone. Contaminated formation water entering the borehole during periods of complete lost circulation may mobilize contaminants from upper lo lower formations. Lost circulation into a formation would be signaled by a water level increase in monitoring wells. The wells would subsequently require development to remove the volume of fluid lost to the formation, including both drilling fluid and contaminated formation water. Monitoring wells exhibiting declining water levels following lost circulation would not require development since drilling water has not entered the zones screened by these wells.  相似文献   

3.
意大利地震紧急事务处置的特点:①地震灾害与其他灾害统一在一个部门进行紧急事务处置。民防部专门负责实施各类灾害应急救援,应急处置职责范围广泛,包括自然灾害与人为灾害的各类灾害应急救援。健全的组织机构保障了应急处置的高效联动。②地震应急响应技术系统联动集成。硬件平台、基础数据库、软件开发与灾害模型研究4个方面进行集成。③高分辨卫星遥感技术实现灾情快速获取。  相似文献   

4.

为满足国家高效低成本开发深层/超深层(埋深4500~9000m)油气资源的战略需求, 亟待发展适合我国地质禀赋的深层/超深层石油地质理论, 创新支撑深层/超深层油气勘探开发的智能导钻技术体系.依托中国科学院A类战略性先导科技专项“智能导钻技术装备体系与相关理论研究”(简称智能导钻系统), 面向深层/超深层系统性开展了油气成藏理论、旋转导向和地质导向钻进技术、远程决策系统和装备试验平台研究.深层/超深层特有的高温、高压环境和水的加氢作用能显著提高油气资源潜力, 多类型优质规模储集体形成的主控因素为“先天基础、后期改造、深埋保持”, 多期成藏改造过程控制了深层/超深层油气藏类型和分布的差异性.围绕智能导钻技术体系的旋转导向(钻)、地质导向(测)、高速传输(传)、地面控制(控)四大子系统, 突破了旋转导向高精度动态测量与控制、非接触高效电能与信号传输, 随钻方位电磁波测井全对称抗干扰天线系、高温高压仪器设计与封装, 井地数据传输非线性流体负载高精度伺服控制、强畸变信道微弱信号提取等关键技术.研制了旋转导向、地质导向、井地传输等10余支井下仪器, 实现了“钻-测-传-控”一体化智能导钻系统的集成总装.目前正在开展系统实钻联调测试, 力图研发“理论研究-技术研发-装备研制-生产应用”全链条自主知识产权的智能导钻装备, 为保障国家能源安全提供理论与技术体系的支撑.

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5.
A fairly detailed structural model of the lithosphere-asthenosphere system (thickness, S- and P-wave velocities of the crust and of the uppermost mantle layers) has been defined in the Calabrian Arc region (Southern Tyrrhenian Sea, Calabria and the northwestern part of the Ionian Sea) in Southern Italy using seismic data from literature as a priori constraints of the nonlinear inversion of surface-wave data. The main features identified by this study are: (1) A very shallow (less then 10 km deep) crust-mantle transition in the Southern Tyrrhenian Sea and a very low vs just below a very thin lid, in correspondence of the submarine volcanic bodies Magnaghi, Marsili and Vavilov, while the vs in the lid is quite high in the area that separates Marsili from Magnaghi-Vavilov; (2) a shallow and very low vs layer in the uppermost mantle in the areas of the Aeolian Islands, Vesuvius, Phlegraean Fields and Ischia, which represents their shallow-mantle magma source; (3) a thickened continental crust and lithospheric doubling in Calabria; (4) a crust about 25-km thick and a mantle velocity profile versus depth consistent with the presence of a continental rifted lithosphere, now thermally relaxed, in the investigated part of the Ionian Sea; (5) the subduction towards northwest of the Ionian lithosphere below the Southern Tyrrhenian Sea; (6) the subduction of the Adriatic/Ionian lithosphere underneath the Vesuvius and Phlegraean Fields.  相似文献   

6.

导向钻井技术的智能化是实现复杂油气藏高效开发的重要途径.本文面向智能导钻系统的实际需求,基于云平台、大数据及人工智能等技术,开展了一体化软件系统的研发.针对整套系统模块众多、功能复杂的问题,首先研发了可扩展模块化底层软件平台,在此基础上建立起集成数据采集、传输、存储、应用与决策为一体的工业化软件系统.本文详细介绍了整套软件系统的研发思路、架构设计、实现方式及各模块主要功能,同时开展了人工智能算法研发和软件平台的集成测试.研发的各软件系统模块不仅实现了现有功能的工程实用化,而且具备良好的扩展性,能够为智能导钻技术的持续性发展奠定基础.

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7.
成功开发制造了检测大型工件的工业CT系统(BJCT450W-Ⅱ)。采用高稳定450kV X射线源,高效线阵列固体光电辐射探测器。数控精密机电扫描工作台,进行平移、旋转扫描运动及切片位置的改变。前端计算机和主计算机组成网络系统,负责系统扫描运行、数据采集和重建断面图像。在图像重建算法和图像处理数学的研究基础上,开发了自己的软件系统。  相似文献   

8.
The outflow of brackish waters from the Tees estuary on an ebb tide forms a plume which is initially spread by the action of gravity. Under quiescent conditions, the rate of vertical mixing of the brackish field is relatively slow and an area of low salinity may form in the surface waters as a result of the superimposition of the outflow plumes from successive tides. A field area of some 70 km2 has been observed to be enclosed by the 34.2 × 10?3 contour.Averaged over a tidal period, the estuary outflow from the Tees forms a broad plume of low-salinity water which extends to seaward of the 20-m contour. The movement of the field thereafter depends on the residual coastal drift which runs either to the northwest or to the southeast with a typical speed of 0.015 m s?1. The tidally averaged vertical mixing coefficient in this offshore field was estimated to be about 10?4 m?2 s?1, which is similar to that off the Wear estuary and an order of magnitude smaller than that calculated for the waters off the Humber.  相似文献   

9.
A single-hole multilevel sampling piezometer system (MLSPS) has been designed by the Geological Survey of Canada (GSC) to be installed using drilling systems that continuously core (e.g., Rotosonic) or continuously sample (e.g., hollow-stem auger, Becker hammer) overburden and that have the flexibility of allowing additional coring (diamond drilling) or sampling (hammer drilling) of bedrock. The GSC-MLSPS (under license to Solinst Canada Ltd.) uses a patented GSC dry injection system for accurate emplacement of filter packs and seals. This system permits (a) the use of variable screen lengths; (b) the complete evacuation of piezometers before introduction of new ground water (no bailing); (c) the use of a number of types of hydraulic tests (e.g., slug, withdrawal/recovery, vacuum, pressure-pulse); (d) ground water sampling under a nitrogen atmosphere; (e) dissolved gas sampling; (f) a great deal of flexibility in the use of design materials; and (g) the elimination of bridging and collapse of filter packs and seals.  相似文献   

10.
11.
The Marine and Atmospheric Research System (MARS) for the Caspian Sea meteorological characteristics is presented, which is implemented in Zubov State Oceanographic Institute. It includes computation of the atmospheric forcing with the Weather Research and Forecasting model, as well as computation of currents, sea level, temperature, salinity and sea ice with the Institute of Numerical Mathematics Ocean Model and the computation of wind wave parameters using the Russian wind-wave model. The results are presented on verification of the hydrometeocharacteristics simulated with the MARS for the Caspian Sea. As well, the retrospective simulation of the thermohydrodynamic characteristics in this basin is performed with MARS for the ice-free period 2003–2013. The important features of the Caspian Sea circulation are shown.  相似文献   

12.
More than fifty heat flow measurements in Italy are examined. The values, corrected only for local influences (when present), are related to the main geological features with the following results: foreland areas, 55±19 mW m–2, foredeep areas, 45±21 mW m–2; folded regions and intermountain depressions, 76±29 mW m–2. In volcanic areas the heat flow rises to in excess of 600 mW m–2. From a tectonic point of view, these values are consistent with the hypothesis that the Apennine chain is intersected by two arcuate structures: the first from Liguria to Latium is very probably a continental arc, that is an are which occurs within a continent, and the second from Campania to Calabria is very similar from geophysical evidence to the classic island arcs.  相似文献   

13.
Detailed records of palaeomagnetic directions from two Upper Cretaceous Umbrian sections are compared with the composite section compiled by Van den Berg et al. [1]. In addition to these sections, fifty-one geographically distributed sites have been studied magnetically and palaeontologically. The Late Miocene-Pliocene fold belt of the Umbrian Apennines is arcuate in outcrop, being convex toward the east. The fold axes are generally tangential to the Umbrian arc, which can be divided into a northern northwestern-trending part and a southern northeastern-trending part. Sites from the north have more westerly declinations than those from the south. The differences are significant at the 95% probability level and most probably reflect the bending of originally straight fold axes or the development of fold axes with initial curvature. The palaeomagnetic directions from Umbria provide important information concerning the Umbrian tectonic deformation, but are not applicable to the Italian autochthon.  相似文献   

14.
1979年 7月 9日江苏溧阳 6 .0级地震造成 31 5 9人死亡 ,损坏房屋 5 5万多间 ,直接经济损失约 2 .4亿元 ,相当于当时溧阳县工农业年总产值的一半左右。 1 990年 2月 1 0日江苏常熟 5 .1级地震造成 2 6人伤亡 ,损坏房屋 1 0万多间 ,直接经济损失达 1 .3亿元以上 ,为全国同级别地震损失之最 (楼宝堂 ,1 996 )。随着社会经济的发展和城市化进程的加快 ,发生在大中城市和人口稠密、经济发达地区的破坏性地震 ,造成的灾害损失呈明显上升趋势。据震害预测 ,目前江苏陆地上若发生 1次 5级左右地震 ,直接经济损失可达 1 0亿元以上 ;若发生1次 6级左…  相似文献   

15.
16.
The in situ vertical circulation column (ISVCC) is a cylindrical containment system consisting of an instrumented steel cylinder used for experimental ground water studies in sandy aquifers. Vertical flow is imposed inside the ISVCC. Although vertical wells are an option, the ISVCC installed in the Borden Aquifer is instrumented with horizontal wells and monitoring ports to avoid creating vertical preferential flow paths. The cylinder was driven downward into the aquifer using a small backhoe equipped with a vibrating plate. The ISVCC penetrates the 2.3-m-thic sand aquifer and is keyed 20 cm into the underlying clay aquitard. The cylinder was installed inside a 2 m X 2 m steel sheet pile enclosure so that the enclosed segment of aquifer could be conveniently dewatered and then excavated to allow installation of the horizontal wells. The dispersivity of the column was comparable to literature values for long sand-packed laboratory columns.
Pure phase DNAPL (tetrachloroethene and 1,1,1-trichloroethane) was slowly pumped into two ports in the center of the column. Following this DNAPL injection, an aqueous solution of vitamin B12 and reduced titanium was circulated through the column to promote degradation of the solvents. Processes observed in the ISVCC included DNAPL distribution, dissolution, and degradation, and geochemical evolution of the aquifer.
The ISVCC provides a convenient means for testing in situ technologies in the experimental stage or for selection of proven technologies to find the most effective at a specific site. It is inexpensive, easy to install, and maximizes control over flow distribution in a heterogeneous aquifer. Its application will be restricted where low hydraulic conductivity beds are present in the aquifer.  相似文献   

17.
—In the last decade temporary teleseismic transects have become a powerful tool for investigating the crustal and upper mantle structure. In order to gain a clearer picture of the lithosphere-asthenosphere structure in peninsular Italy, between 1994 and 1996, we have deployed three teleseismic transects in northern, central, and southern Apennines, in the framework of the project GeoModAp (European Community contract EV5V-CT94–0464). Some hundreds of teleseisms were recorded at each deployment which lasted between 3 and 4 months. Although many analyses are still in progress, the availability of this high quality data allowed us to refine tomographic images of the lithosphere-asthenosphere structure with an improved resolution in the northern and central Apennines, and to study the deformation of the upper mantle looking at seismic anisotropy through shear-wave splitting analysis. Also, a study of the depth and geometry of the Moho through the receiver function technique is in progress. Tomographic results from the northernmost 1994 and the central 1995 teleseismic experiments confirm that a high-velocity anomaly (HVA) does exist in the upper 200–250 km and is confined to the northern Apenninic arc. This HVA, already interpreted as a fragment of subducted lithosphere is better defined by the new temporary data, compared to previous works, based only on data from permanent stations. No clear high-velocity anomalies are detected in the upper 250 km below the central Apennines, suggesting either a slab window due to a detachment below southern peninsular Italy, or a thinner, perhaps continental slab of Adriatic lithosphere not detectable by standard tomography. We found clear evidence of seismic anisotropy in the uppermost mantle, related to the main tectonic processes which affected the studied regions, either NE–SW compressional deformation of the lithosphere beneath the mountain belt, or arc-parallel asthenospheric flow (both giving NW–SE fast polarization direction), and successive extensional deformation (~E–W trending) in the back-arc basin of northern Tyrrhenian and Tuscany. Preliminary results of receiver function studies in the northern Apennines show that the Moho depth is well defined in the Tyrrhenian and Adriatic regions while its geometry underneath the mountain belt is not yet well constrained, due to the observed high complexity.  相似文献   

18.
Seismotectonic Model and CN Earthquake Prediction in Italy   总被引:4,自引:0,他引:4  
—The choice of the regions is essential in the application of the algorithm CN, therefore a seismotectonic criterion for their definition is tested. In order to take into account the geodynamic complexity characterising the Italian peninsula, we established to strictly follow the seismotectonic zones, including in each region only zones with similar seismogenic behaviour and the transitional zones connected to them. Three regions have been successfully defined in this way, corresponding approximately to the North, Centre and South of Italy. The reduction of the space-time uncertainty and the increase of the stability of prediction results obtained with this regionalisation, with respect to the previous applications of CN in Italy (Keilis-Borok et al., 1990; Costa et al., 1995, 1996), can be interpreted as a validation of the seismotectonic model.  相似文献   

19.
在日本东京2005年10月19日危机管理产业展上, 展示了一种袖珍生命探测仪SAR2700, 它能在地震、火灾的废墟中, 快速探测出被埋在废墟中的生命的准确位置. 其最大特点是: 可以依据被困者的心跳电磁波强度和方向, 照射出其所在的准确位置和地下深度.  相似文献   

20.
A multi-parametric study of empirical relationships between macroseismic data and magnitude is presented for the Italian region by the analysis of a new extended data set concerning 146 earthquakes. The available magnitude determinations include all of the most intense earthquakes which occurred in Italy in the last century and have been obtained by an accurate revision of original instrumental data. Intensity data have been revised and upgraded on the basis of the most recent studies: only local intensities directly documented have been used. Macroseismic determinations ofM s ,m B andM wa magnitudes have been performed. The empirical relationships between maximum felt intensity (I max ) and magnitude have been determined by the use of a distribution-free approach and a linear regression analysis. This last parameterization allows for the explanation of more than 60% of the variation in magnitude. In order to improve these results, the linear dependence between magnitude,I max and average distances (in logarithm) corresponding to fixed attenuation values has been explored. The comparison between instrumental magnitudes and corresponding macroseismic estimates obtained from empirical relationships shows that the respective uncertainties are comparable.  相似文献   

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