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1.
Abstract

With the growing demand for underwater refill engineering, the construction technology of implementing fluidized solidification in underwater pouring has recently received increased attention. However, the environmental impact of underwater casting on surrounding water bodies, especially when the silt is polluted, is still unclear. In this study, a simulated underwater pouring test and a static immersion release test were conducted separately to study the quality of the surrounding water during and after pouring. The results showed that fluidized-solidified silt casting could increase the pH of the surrounding water, even after the pouring had stopped, by approximately 1.0 and the turbidity could reach 200 NTU. No diffusion of Zn and Cu into the surrounding water was observed and while Ni and Cr exhibited slight diffusion, this was at a level well below international water quality standard. During construction, reducing the distance from the seafloor to the bottom of the pouring catheter could reduce the level of pollution. After construction, the use of neutral solidified materials can effectively reduce the pH of the surrounding water and the potential risk of heavy metal dissolution.  相似文献   
2.
GPU accelerated marine data visualization method   总被引:1,自引:0,他引:1  
The study of marine data visualization is of great value. Marine data, due to its large scale, random variation and multiresolution in nature, are hard to be visualized and analyzed. Nowadays, constructing an ocean model and visualizing model results have become some of the most important research topics of ‘Digital Ocean'. In this paper, a spherical ray casting method is developed to improve the traditional ray-casting algorithm and to make efficient use of GPUs. Aiming at the ocean current data, a 3D view-dependent line integral convolution method is used, in which the spatial frequency is adapted according to the distance from a camera. The study is based on a 3D virtual reality and visualization engine, namely the VV-Ocean. Some interactive operations are also provided to highlight the interesting structures and the characteristics of volumetric data. Finally, the marine data gathered in the East China Sea are displayed and analyzed. The results show that the method meets the requirements of real-time and interactive rendering.  相似文献   
3.
通过实验研究,用甲苯磺酸作催化剂的呋喃树脂自硬砂与稀土镁作催化剂生产的球铁件,通常在其铸件表层出现异常组织。提出导致异常组织产生的原因,同时又降低了试件的冲击值,并且采用反应型或屏蔽型涂料将可防止球铁件表层异常组织缺陷,为生产性能良好的球铁件提供技术依据。  相似文献   
4.
具有重要岩石学和构造学意义的科马提岩,最吸引人同时又最令人困惑的特征之一是它的鬣刺结构和分层构造。本文从喷出地表的岩桨冷凝时温度分布、熔体性质与结晶作用的密切联系,把科马提岩浆喷发形成的岩流作为一个冷凝整体。通过与金属铸锭浇注成形和矿石冶炼生产的比较,发现它们在冷凝固结过程中温度场特征、熔体的性质、结晶能力和结晶方式都有十分相似的特点,并以此为出发点详细解析了科马提岩的鬣刺结构和岩石分层构造的形成  相似文献   
5.
CGD-1型大口径全套管冲击抓斗主要是配套全套管钻机施工而研制的。该抓斗主要适用于复杂地层的施工。介绍了该抓斗的技术参数、性能特点、主要结构及试验情况。  相似文献   
6.
Pipelines are an important part of urban infrastructure development. As part of a virtual globe (VG), the high-efficiency and high-quality visualization of 3D large-scale and high-density urban pipelines is of great importance. This paper proposes a GPU-based pipeline ray casting method for the visualization of urban-scale pipelines in the framework of a VG. The method involves the initial partitioning of the pipeline data into tiles, based on the relationship between the pipeline layer scale and the discrete global grid system (DGGSs). The pipeline centerline in each tile is then segmented and encoded, and a coarser pipeline bounding volume is subsequently constructed using a geometry shader. Finally, the fine 3D pipeline is rendered using a pixel shader. The results of the experimental implementation of the proposed method show that it satisfies the requirements for the multiscale visualization of pipelines in a VG. Moreover, compared with the traditional polygon-based method, the method facilitates a 20% increase in rendering frame rate for the same pixel level accuracy display effect. It also enables the visualization of the thickness of the 3D pipeline without any obvious effect on the rendering efficiency.  相似文献   
7.
陕西南部宁强地区的李家沟剖面灯影组高家山生物群产有大量磷酸盐化实体化石,包括各类管状化石、瓶状化石、疑难化石以及钙化蓝细菌等,类型丰富。近年来,随着研究的深入,微生物假形化石在该生物群中也被不断发现。由于微生物假形化石是生物死亡后腐解埋藏过程中生物体被微生物(球状和丝状蓝细菌)直接取代,因而原始生物体的结构形态得以完好保存。微生物可以通过改变环境中的物理化学条件使磷酸盐富集和快速堆积,对生物的非矿物组织包括软躯体的保存起到了很重要的作用。根据替代程度不同可以划分为完全替代类型和未完全替代类型。这一发现提供了高家山生物群中生物非矿化组织的另一种保存方式。微生物通过铸型完整复制了生物软躯体以及可能的胚胎形态特征,提供了对此时期软躯体保存的新认识。  相似文献   
8.
采用搅拌铸造法在真空度为200 Pa的条件下制备得到含有微量氧化物的SiCp/Mg复合材料,通过显微组织观察和动态热机械分析等对其阻尼特性进行了研究。结果表明,所制备的SiCp/Mg复合材料基体晶界处分布着附着有氧化物的网状结构,且随着SiCp含量的增加,网状结构增多,且分布更加分散。此结构增大了位错密度和晶粒界面滑移,位错脱钉和界面滑移在振动过程中耗能量增大,因此所制备的SiCp/Mg复合材料具有理想的阻尼性能。  相似文献   
9.
为了提高四川省防雷减灾工作效率,推动雷电服务数字化、网络化、集约化、规范化、标准化,实现快速、准确、高效的雷电短时临近预警,四川省防雷中心协助中国气象科学研究院,共同研制开发了“四川省雷电短时临近预警系统”.目前四川省防雷中心已经结合本地的实际情况开展雷电临近预警业务试运行.同时在成都、凉山、眉山、绵阳、乐山等市州气象台进行区域化雷电监测预警预报推广应用,初步实现雷电监测预警预报业务和服务,并在2010 ~2011年几个重大天气过程中成功进行了雷电预警预报,同时对当地气象台站进行强天气过程预测预报提供了辅助手段,得到了有关职能部门及当地各级政府的充分肯定.  相似文献   
10.
结合常德市第一人民医院门急医技大楼的工程实际,介绍了深基坑底板地层压力注浆的机理,探讨了设计过程中几个主要参数的取值,指出了压力注浆的施工方法。  相似文献   
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