基于固定扫描点的建筑物三维测量方法

提出一种基于固定激光扫描点的三角投影法测量建筑物大目标三维尺寸的方法。利用线结 构光旋转扫描形面和对投影图像进行处理分析,实现三维重建和测量。导出了三维几何尺寸的计算公式,进行了仿真实验,获得满意的数据。在进行建筑物等大目标三维测量时,不需激光器和传感器平行移动,减少误差来源,提高精度,方便可行。     

三参量速度分析的迭代算法

采用预求倾角法进行三参量速度分析时，首先要确定地下界面的倾向和倾角。若没有准确速度，就求不准倾向和倾角，因此无法一次求得准确的结果。若采用迭代算法，则可以使三参量逐渐向精确值逼近。在地层倾角小于４５＾０的情况下，迭代是收敛的。在有噪音的情况下，噪音会使叠加道集上同相轴的时间发生变化，从而影响倾向的确定，因此在迭代的每一步，都必须估算倾向。理论实际资料的试算表明，采用迭代方法求取地下界面参数是切实可     

三相最佳立体铁心的研究

讨论了立体叠铁心三框式、立体叠铁心三柱式和立体卷铁心准三柱式变压器的铁心结构,并阐述了它们与节约材料(节电),节省剪、叠(卷)铁工时和节省横剪(卷)设备费的关系,指出了三相平面卷铁心结构的种类。     

三维实体造型技术在装载机工作装置设计中的应用

机械产品都是具有三维空间形状的物体,设计者头脑中建立起来的首先是其三维实体形状。过去常用正投影方法,把头脑中的三维实体分别投影到多个二维视图上,而每个视图只能表示设计对象的局部信息。随后其他技术人员又需要将分散于各个视图中的局部信息,通过想象加以综合,恢复为设计者头脑中的原来的三维实体形状,再对其进行分析、工艺设计和加工等工作,这在实际工程中这往往是非常复杂的过程。如果上述过程中哪一步产生错误,就得返回前边的过程,纠正后再继续进行。如此将耗费大量时间、人力和物力。如果采用三维实体造型技术,直接用三维实体来表达设计对象,并预先在计算机上做装配、检查、分析、修改和加工等工作,这不但可省去从三维转换为二维,再从二维恢复为三维这样的人工思维过程,而且设计过程将更加直观、全面,更能符合设计需要,效率也将大大提高,还解决了二维图纸中长期表达不清楚的问题。     

Evaluation of drug toxicity with hepatocytes cultured in a micro-space cell culture system

A micro-space cell culture system was recently developed in which cells such as hepatocytes can be cultured and formed into a multicellular three-dimensional (3D) architecture. In this study, we assessed the performance of HepG2 cells cultured in this micro-space cell culture system in a drug toxicity test, and evaluated the effects of micro-space culture on their hepatocyte-specific functions. The micro-space cell culture facilitated the formation of 3D HepG2 cell architecture. HepG2 cells cultured in a micro-space culture plate exhibited increased albumin secretion and enhanced mRNA expression levels of cytochrome P450 (CYP) enzyme compared to those cultured in a monolayer culture. When the cells were exposed to acetaminophen, a hepatotoxic drug, the damage to the HepG2 cells grown in micro-space culture was greater than the damage to the HepG2 cells grown in monolayer culture. In addition, human primary hepatocytes grown in micro-space culture also exhibited increased albumin secretion, enhanced CYP mRNA expression levels and increased sensitivity to acetaminophen compared to those grown in monolayer culture. These results suggest that this micro-space culture method enhances the hepatocyte-specific functions of hepatocytes, including drug-metabolizing enzyme activities, making hepatocytes grown in the micro-space culture system a useful tool for evaluating drug toxicity in vitro.     

Production behavior of methane hydrate in porous media using huff and puff method in a novel three-dimensional simulator

The gas production behavior of methane hydrate in porous media using the huff and puff method was investigated in the Cubic Hydrate Simulator (CHS), a novel developed three-dimensional 5.8-L cubic pressure vessel. Three horizontal layers equally divide the CHS into four regions. A 9-spot distribution of the vertical wells, a single horizontal well and a 25-spot distribution of the thermometers are arranged on each layer, respectively. The vertical wells at the axis of the CHS were used as the injection and production wells. The huff and puff method includes the injection, soaking and production stages. The amount of water injected and produced, the gas production rate, the percentage of the hydrate dissociation and the gas-to-water ratio were evaluated. Under the thermodynamic conditions in this work, the gas production from the sediment in this work using the huff and puff method is economically profitable from the relative criterion point of view. The sensitivity analysis demonstrates the dependence of the gas production on the initial hydrate saturation, and the temperature and the injection rate of the injected hot water.     

蛇形益智魔方的三维路径求解算法

蛇形益智魔方是智力魔方的一种,由27个两两相连的小正方体组成。文章通过计算机图形学的概念建立空间三维坐标模型,对模型中关键点进行分析归类,对空间中每个方块体可能的坐标点进行了递归公式推导,最后利用三维空间坐标的遍历算法采寻找蛇形魔方所有可能的解,指出了模型的使用前景。     

柴油机进气道三维贴体网格生成

本文应用求解poissou方程的逆变换和分形耦合成贴体网格的方法,对492柴油机螺旋进气道进行了三维贴体网格划分,生成的网格光滑均匀,质量很好。     

Mapping oxygen-induced temperature patterns of round bale silage based on 3D stepwise-profiling measurement

Abnormal rise of temperature in silage is regarded as a signal of aerobic deterioration caused by the permeation of atmospheric oxygen into the silage, which indicates the growth of lactate-assimilating yeasts and energy release. Although baled silage has distinct advantages over other forms of silage, the high surface-area to volume ratio of the bale leads to a high risk of aerobic deterioration due to plastic cover damage. With an objective to spatially assess any aerobic deterioration within round-bales silage, we modified a bale-penetrometer that is capable of profiling temperature distribution. For each tested bale having a cylindrical volume of 2.154 m³, 72 path profiles including 504 stepwise measurements were made. Furthermore, two paths were re-profiled to check if the proposed invasive method has a significantly contaminative effect on the internal temperature field. The resulting R² = 0.9978 between the profiling data and the re-profiling data verified that the contamination due to the invasion of ambient air following the temperature probe penetration could be negligible. We presented two mapping methods, one for two-dimensional (2D) cross-sections and one for three-dimensional (3D) volumes. To demonstrate the applicability of the proposed method, six representative samples of round bales with varied damage to plastic covers were tested. All temperature patterns, generated in both 2D- and 3D-space, were informative and clearly interpretable. Therefore, we conclude that the tested measurement method can benefit advance of bale silage research and production.     

激光扫描技术在数字化矿山建设中的应用

介绍了三维激光扫描技术具有快捷、方便、准确、动态、全数字化、高精度等优点,并通过三维激光扫描技术在山东金岭铁矿的实际应用,建立了山东金岭铁矿三维巷道模型,并和井下人员定位系统相配合,可以更加直观地掌握井下人员分布,也有利于进行在线监控和用于灾害应急疏散救援工作。