景洪市嘎栋地热井特征及成井工艺总结分析

景洪盆地内蕴藏有丰富的地热资源。通过对景洪市嘎栋地热资源勘查地热井地质、施工情况及成果进行介绍,结合勘查施工实践,针对地热资源勘查开发、地热钻井施工、成井工艺及钻井过程中地质问题等有关内容进行经验总结并分析,对地热地质条件与地热井施工之间结合进行一些经验探讨,并对现行地热井规范中关于井身结构设计、取水层位确定、单井资源量计算等问题提出一定疑问。旨在通过实践及疑问探讨,力图找出为地热资源勘查开发提供值得借鉴的经验和教训。     

延庆千家店地区硅化木赋存层位及形成时代分析

北京延庆千家店土城子组中的硅化木自发现以来,得到了众多学者的关注,但关于硅化木的赋存层位和形成时代一直未有定论,目前主流观点认为硅化木广泛发育于土城子组一段和二段的下部,关于其形成时代则自侏罗纪早期至白垩纪早期的论述均有,这种争论显然不利于木化石的保护、科普和进一步深化认识。在千家店土城子组进行的考察结果展现出与前人观点不同的线索。实地考察、剖面测量和年龄测试结果显示:原位埋藏硅化木形成时代应为晚侏罗世早期,赋存层位为土城子组一段下部,而土城子组二段下部的沉积特征反应出当时水位频繁升降,水体能量剧烈变化,火山活动暂时陷入沉寂的沉积环境,较难满足形成木化石的基本要求。     

强潮流作用下桥墩不对称“双肾型”冲刷地貌特征与机理

本文在海图地形资料分析桥轴线附近的海床自然冲刷的基础上,利用多波束测深技术研究大桥主墩附近局部冲刷地形。结果表明,该大桥桥位附近地形冲刷较显著,且大桥主墩位置有持续冲刷的趋势;主墩上、下游群桩最大冲刷深度呈上游最深、中部淤积、下游渐深的不对称形态,最大局部冲刷深度为4 m;桥墩整体冲刷坑形态呈南北“双肾型”;潮流流向与桥墩迎流面存在偏南的入射角,使得各桥墩南侧的最大冲深和冲刷范围均大于北侧。     

日本囊对虾Marsupenaeus japonicus)组织蛋白酶D基因克隆及表达分析

组织蛋白酶D是溶酶体天冬氨酸蛋白酶家族的主要成员,广泛参与动物机体细胞内蛋白质的降解过程,对维持细胞稳态和正常代谢具有重要的作用。为研究组织蛋白酶D在甲壳动物非特异性免疫和幼体发育过程中的作用,本研究采用RACE技术首次克隆得到日本囊对虾组织蛋白酶D基因cDNA序列,命名为MjCatD,其中开放阅读框长为1161 bp,编码386个氨基酸残基。序列分析和同源建模显示该基因编码的蛋白含有保守的N-糖基化位点、天冬氨酸蛋白酶签名序列、酶活化位点和非消化性组织蛋白酶D的特征序列,并且呈保守的双叶形结构。同源性比较和系统进化分析发现,MjCatD与斑节对虾、美洲螯龙虾和脊尾白虾相似性较高,并且与它们紧密聚为一支。实时荧光定量PCR结果显示,MjCatD基因在日本囊对虾多个组织中均有表达,其中肝胰腺中表达量最高。在白斑综合征病毒(white spot syndrome virus, WSSV)感染后3～24 h日本囊对虾肝胰腺中MjCatD的表达量逐渐下降,而在48 h急剧上调至最高表达量并且与对照组差异极显著(P<0.01)。此外,MjCatD基因在幼体发育不同阶段中也表现出明显的变化趋势。以上研究表明,MjCatD基因可能参与日本囊对虾先天免疫反应和幼体发育过程。     

象山港海洋牧场示范区大型底栖生物的时空变化

根据象山港海洋牧场示范区建设前(2011年)、建设中(2012年)、建设后(2013年)对象山港全港区、邻近区、示范区11个站位,进行5个航次调查所获得的大型底栖生物的资料,对比分析建设前后大型底栖生物的时空变化。结果表明:共鉴定出大型底栖生物59种,建设后建设中建设前,优势种变化明显。大型底栖生物密度、生物量表现为:建设前建设中建设后;建设中建设后建设前。多样性指数H’、丰富度指数d均表现为:建设前建设后建设中,均匀度指数J则表现为建设中建设后建设前。多因子方差分析结果表明:建设前后,大型底栖生物种类数、栖息密度、生物多样性指数均存在显著性差异。根据群落聚类及n MDS排序分析,建设前后大型底栖生物群落组成存在明显差异,双因素相似性分析(ANOSIM)结果同时表明,群落建设前后存在显著性差异(综合检验R=0.215,P=0.004)。SIMPER分析,大型底栖生物群落的平均相似性建设前建设后建设中。根据调查站位的数据作出丰度/生物量比较曲线(ABC曲线)分析表明,建设中大型底栖生物受到了强烈的干扰,人工鱼礁投放、大型海藻移植、增殖放流会对其周围海域产生影响,但建设后扰动消失,表明随着时间的推移,海洋牧场建设过程中带来的扰动逐渐减小,并围绕鱼礁群逐渐形成新的人工生态系统。     

Bias estimation and correction for triangle-based surface area calculations

The calculation of surface area is meaningful for a variety of space-filling phenomena, e.g., the packing of plants or animals within an area of land. With Digital Elevation Model (DEM) data we can calculate the surface area by using a continuous surface model, such as by the Triangulated Irregular Network (TIN). However, just as the triangle-based surface area discussed in this paper, the surface area is generally biased because it is a nonlinear mapping about the DEM data which contain measurement errors. To reduce the bias in the surface area, we propose a second-order bias correction by applying nonlinear error propagation to the triangle-based surface area. This process reveals that the random errors in the DEM data result in a bias in the triangle-based surface area while the systematic errors in the DEM data can be reduced by using the height differences. The bias is theoretically given by a probability integral which can be approximated by numerical approaches including the numerical integral and the Monte Carlo method; but these approaches need a theoretical distribution assumption about the DEM measurement errors, and have a very high computational cost. In most cases, we only have variance information on the measurement errors; thus, a bias estimation based on nonlinear error propagation is proposed. Based on the second-order bias estimation proposed, the variance of the surface area can be improved immediately by removing the bias from the original variance estimation. The main results are verified by the Monte Carlo method and by the numerical integral. They show that an unbiased surface area can be obtained by removing the proposed bias estimation from the triangle-based surface area originally calculated from the DEM data.     

Preparation of iron phosphate from sludge sourced from the electrocoagulation treatment of source-separated urine

In order to prepare iron phosphate by waste sludge, we report a method for effective utilization of the sludge obtained from the electrocoagulation treatment of source-separated urine. The sludge was dissolved with hydrochloric acid and pretreated with H₂O₂ and Na₃PO₄; finally, NaOH was added to precipitate iron phosphate from the solution. Thermal treatment of the precipitate at 750 °C in air yielded crystalline quartz-like anhydrous FePO₄. The precipitate was characterized by a number of thermal techniques such as thermogravimetry/differential thermal analysis, scanning electron microscopy, and X-ray powder diffraction.     

Autonomic visiting in digital 3D scenes

Human-machine interactive visiting and fixed-route visiting are currently the main roaming modes in digital three-dimensional (3D) scenes. However, in general, when a person visits an attraction area, s/he does not follow a fixed path, but instead wander about according to his/her interests. Here, we propose a new roaming mode, called autonomic visiting. That is, in a digital 3D scene, a user selects several interest spots, then a route connecting these spots can be automatically determined and 3D scene can be seen along this route. This study presents a technical approach that enables the realization of autonomic visiting in 3D scenes. Firstly, Delaunay triangular meshes for the terrain in 3D scene are established. Secondly, a plane-growth algorithm and a line-connection algorithm are introduced to automatically mend the broken parts of these triangular meshes. Thirdly, the triangular meshes are then merged and differently weighted according to different layers. Finally, a progress-zone transmission algorithm is presented to optimal the shortest route, which is derived from A-Star (A*) algorithm. Digital 3D campus of Nanjing University, China, is taken as the experimental materials. The experimental results prove the effect of the proposed approach.     

Simulating train moving loads in physical model testing of railway infrastructure and its numerical calibration

Ballastless high-speed railways have dynamic performances that are quite different from those of conventional ballasted railways. The essential dynamic characteristics of high-speed railways due to passing train wheels, such as the cyclic effect, moving effect, and speed effect, were put forward and discussed. A full-scale accelerated railway testing platform for ballastless high-speed railways was proposed in this study. The feasibility of the sequential loading method in simulating train moving loads, and the boundary effect of the proposed physical model of ballastless railways, was investigated using three-dimensional finite element models. A full-scale physical model, 5 m long, 15 m wide, and 6 m high, was then established according to practical engineering design methods. Using a sequential loading system composed of eight high-performance hydraulic actuators, loads of a moving train with highest speed of 360 km/h were simulated. Preliminary experimental results of vibration velocities were presented and compared with field measurements of the Wuguang high-speed railway in China. Results showed that the experimental results coincided with the field measurements, demonstrating that the full-scale accelerated railway testing platform can simulate the process of a moving train and realistically reproduce the dynamic behaviors of ballastless high-speed railways.