Steady motion and spiral patterns in typhoon

INTRODUCTIONItiswellknownthattyphoonSareakindofmooscaleatmosphericvortexovertheoceaninthelOwerlatitudes.Thethree-dimenSionalstructures(Anthes,1976)oftyphoonS,inwhichthereareaneyeandthewarrncenterwheretherearealocallOwpressurewithcycloniccirculationan...     

极浅海水区浅地层剖面浅层失真及校正

浅地层剖面调查是进行大陆架第四纪地质研究，浅海灾害地质研究和工程地的南调查的重要手段，剖面的质量与解释精度将对研究成果的可靠性造成直接影响。由于浅地层剖面系统的震源与水听器有一定的距离，因此它只是近似的垂直发射垂直的接收单道地震系统，当水深地了浅时造成了剖面浅层的失真，导致各层位的反射时间延迟，层与层之间双程走时缩短，计算出的层速度偏高，在地形起伏较大的区域，将造成地形失真，在潮差大的区域，计算出     

浙江海面变化的灰色模型分析与预测

应用灰色模型理论，分析了各影响海面变化因素的影响力度，指出影响浙江海面趋势性变化的主要因素是气温；建立了海面变化的灰色气温模型，其计算值与实测值吻合良好，可根据气温变化趋势预测未来海面变化趋势。若未来百年全球气温再上升１．５－５．５℃，浙江海面将对应上升２４－７８ｃｍ。灰色模型模拟还显示，未来平均高潮位于上升速率明显大于平均低潮位上升速率，潮差将逐渐增大，在相同平均海面升幅的情况下，未来海面上升对     

Analysis of influencing factors on fine sediment flocculation in the Changjiang Estuary

Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes.     

Study on visual control system of acoustic in situ measurement technology for survey of seafloor sediment

Abstract

A new kind of visual acoustic measurement system was developed to obtain the acoustic characteristics of seabed sediment and the working state of in situ measuring equipment in real time. The control unit of the system structure is mainly made up of the underwater control unit and the deck control unit. In comparison with similar traditional systems, the system can transmit the working video image, the measured acoustic data and the waveform synchronous from the underwater control equipment to the deck control unit through the connecting cable. Apart from self-contained in situ measurement, the working modes of it include visual online real-time control. In order to guarantee the stability and measurement precision of the video control system, the process control of in situ measurement was strictly tested in the experimental tank. In 2017, sea trials of the in situ measurement system was carried out in the South China Sea. In the process, data related to measurement, including the acoustic velocity and attenuation coefficient of the seabed sediment, were obtained as well. The results from sea trials show that the control process of the visual system is intuitive, reliable and accurate, and therefore it can be popularized and applied.     

加强海洋灾害地质学研究,减少海洋工程灾害

随着我国近海油气资源的开发及海洋工程的需要,海洋灾害地质学这一边缘学科正在我国兴起和迅速发展。本文对这一学科的研究对象、研究领域以及灾害地质因素分类进行了概述,并对海洋灾害地质学的特点与应用前景,进行了初步总结,最后对该学科的发展方向提出了积极建议。     

Failure Mechanism and Control of Surrounding Rock of Mining Roadway Under Overlying Goaf

Geotechnical and Geological Engineering - Aiming at the deformation and failure of roadway surrounding rock and its control problems under goaf in upper and lower coal seam mining of Buertai Coal...     

3D geological architecture and ore -controlling structures of the Paomaping Zn-Pb deposit at the Jinding ore field,Lanping County,SE Tibetan PlateauSCIEI北大核心CSCD

滇西北金顶超大型铅锌矿田位于青藏高原东南缘兰坪中-新生代盆地中部,是三江成矿带中南段最典型的密西西比河谷型(MVT)矿床之一,其构造控矿和盆地流体成矿特征明显受控于印度-欧亚大陆碰撞有关的区域挤压构造。近年来,矿床浅部地质条件与资源状况已被充分揭露,但其深部地质结构、构造控矿差异性仍不清楚,这也制约了成矿预测和找矿新发现。本文以矿田东北部的跑马坪大型隐伏矿床为研究对象,利用三维地质建模及空间分析方法,识别矿化空间变化及其与断层、不整合面和地层岩性的配置关系,分析构造控矿规律及可能的流体运聚趋势。结果表明,跑马坪铅锌矿床的成矿作用与近E-W向挤压构造对中新统金顶砂泥岩(Mio-j)与上三叠统三合洞组(T_(3)s)不整合面的差异性破坏关系密切,近NS和NE向逆断层与NW向走滑-掀斜断层组合是最重要的控矿构造。其中,近NE向逆断层与不整合面是成矿流体运聚的主要通道,而近于平行的NW向走滑-掀斜断层上盘的T_(3)s高孔渗性角砾状灰岩、含灰岩角砾砂岩及裂隙带因为富含H_(2)S等还原性流体而成为与Mio-j富含金属氧化性盆地卤水混合和金属沉淀就位的最有利空间。由此,逆断层和走滑-掀斜断层组合、特定地层岩性与不整合面联合控制了流体汇聚与混合成矿作用,断层沟通了同位叠加的上三叠统油气藏储层和渐新统-中新统盆地卤水(带),这是铅锌成矿的关键。该成矿模型在金顶矿田及邻区与类似地区均具有普遍指导意义。最后,本文预测沿跑马坪矿区深部及其南北侧延伸区域还存在多条NE向隐伏控矿断层,其成矿潜力大,是下一步找矿勘查的有利靶区。     

Quantitative identification of cutoff wall construction defects using Bayesian approach based on excess pore water pressure

Acta Geotechnica - Cutoff wall has been widely used as a barrier to prevent the migration of contaminants in aquifers. Hydraulic impermeability and homogeneity should be ensured before operation....     

Evaluating the effect of active ions on the early performance of soft clay solidified by modified biomass waste-rice husk ash

Acta Geotechnica - Soft clay generally cannot be directly used as subgrade material due to its poor engineering characteristics. The application of rice husk ash (RHA) for the solidification of...