基于等高线的黄土高原小流域地形虚拟

黄土高原地形三维虚拟是"数字黄土高原"的基础,可为区域水土保持生态建设提供科技支撑。针对直接在地理信息系统软件中观察三维场景存在的控制交互能力不足问题,提出综合利用地理信息系统软件的地形插值算法,基于MFC框架下的OpenGL程序设计的思路,实现地形的真实感三维虚拟。以黄土丘陵沟壑区康家沟小流域为例,等高线数据在AutoCAD和ArcView软件中处理,生成ASCII格式的规则网格DEM数据,依据它们绘制三角形带,采用加权平均法求得各点的法向量,设置光照与材质模式,添加动态天空背景,实现了该流域地形的真实感三维虚拟,并增加交互能力,完成自由漫游与多角度观察。

基于林相图的森林景观可视化

景观可视化是近30年来逐步发展起来的，特别是计算机软件、硬件技术的发展，使人们对复杂的自然系统进行模拟和可视化成为可能。并且，在环境决策中，公众的参与越来越普遍，积极的公众参与是可持续发展、生态系统管理和21世纪议程发起的基础和先决条件。因此，景观可视化已成为了公众交流和参与环境教育、气候变化、景观规划、林业管理、开发和建设项目的景观影响评价等方面的一种有效手段。 目前林业部门一直采用数字林相图对森林进行表述，但1）数字林相图的平面特性，虽然使用者可以通过等高线来理解森林所在的地形，但必须通过思维的分析转换过程；2） 数字林相图中树种用抽象的符号表示，阅读者要看懂图必须先将树种符号记住或一一对比，不直观；3）数字林相图中在同一小班内难以表现树种空间分布等信息。为了解决数字林相图的这些问题，本论文探索简便快捷的森林景观可视化的方法与应用。 采用三种数据源，即遥感影像数据、地形图数据、林相图数据，将地理信息系统的二次开发技术与VRML（虚拟现实模型语言）相结合，选用集成开发模式，基于.NET平台和ArcGIS Engine开发包，用vb.net语言进行开发，利用景观可视化技术构建并实现了森林景观的可视化。研究结果较直观地再现了该流域的主要景观类型，为流域的景观管理提供了一种全新的，更为直观的管理工具。该工具可以帮助人们进一步理解景观格局及其时间动态，可以对未来景观评价、生态规划提供各种预案，供社会和专家进行不同角度的评价。最后讨论了景观可视化研究中存在的主要问题，提出了一些解决办法，以及进一步的研究方向。

Evaporation of Ethanol Drops on a Heated Substrate Under Microgravity Conditions

We present in this paper results obtained from a parabolic flight campaign regarding ethanol sessile drop evaporation under reduced gravity conditions. Drops are created using a syringe pump by means of injection through a PTFE (polytetrafluoroethylene) substrate. The drops are recorded using a video camera and an infrared camera to observe the thermal motion inside the drop and on the heating substrate. The experimental set-up presented in this paper enables the simultaneous visualization and access to the heat flux density that is transferred to the drop using a heat flux meter placed between the heating block and the PTFE substrate. We evidence original thermal spreading phenomena during the ethanol drop creation on a heated PTFE substrate. The drop exhibits specific behaviour which is discussed here. This work is performed in the frame of a French-Chinese collaboration (project IMPACHT) for future experiments in a Chinese scientific satellite.

Study on conical columns with different conical angles for semi-preparative liquid chromatography

The dynamic flow profiles and separation performances in conically shaped preparative liquid chromatographic columns (inlet i.d. larger than outlet i.d.) with three different angles (7, 10 and 15degrees) were studied and compared with cylindrical column of the same length and internal volume. The shapes of dynamic flow profiles were studied by on-column visualization method. The transparent chromatographic columns made of polymethyl methacrylate (PMMA), packed with C-18 bonded silica, were immerged into a cubic pool filled with glycerol to eliminate the cylindrical and conical lens effect. The flow profiles of colored iodine solution in the columns were observed clearly using cyclohexane as mobile phase since the refractive indices of C-18, column wall and the mobile phase are very close. In the conical column of 15degrees (20-7 mm i.d.) the mobile phase in the central region migrated slower than in wall region as it moved toward the column outlet, while in the conical column of 7degrees (17-11 mm i.d.) the mobile phase in the central region migrated faster than in wall region just like in cylindrical column. We found that a plug-like flow profile was generated in the conical column of 10degrees (18-9 mm i.d.) during the whole migration process. A carmine and brilliant blue mixture was used as a probe to test the separation ability of the columns. The resolutions of the two compounds on the conical column of 7, 10, 15degrees and on the cylindrical column were 0.6, 1.57, 1.29 and 0.8, respectively. (C) 2003 Elsevier B.V. All rights reserved.

Study on conical columns for semi-preparative liquid chromatography

The dynamic flow profiles and column efficiencies in conically shaped semi-preparative liquid chromatographic columns (inlet ID larger than outlet ID) with two different conical angles (7degrees and 15degrees) were studied. The dynamic flow profiles were studied by an on-column visualization method. Conical columns were compared with cylindrical column of the same length and internal volume. The results showed that the flow profile of a sample band in the conical column of 7degrees (50 mm x 17 mm --> 11 mm ID) was parabolic in shape. The sample band migrated slower in the wall region than in the central region, as in the cylindrical column (50 mm x 14 mm ID). However, the sample band in the conical column of 15degrees (50 mm x 20 mm --> 7 mm ID) migrated slower in the central region than in the wall region, resulting in a reverse parabolic flow profile, in contrast to that in cylindrical column. This indicated that a flat flow profile might be realized in a conical column with a conical angle between 7degrees and 15degrees. The conical column of 15degrees had the highest column efficiency among the three columns under the same conditions. Compared with the cylindrical column packed with identical packing material, the conical column of 15degrees had 22%-45% higher column efficiency and 11%-27% higher peak height.

信息可视化中的交互技术研究

随着计算技术的发展，使海量信息得以存在并迅猛增长。近年来商务智能、生物信息学、社会网络分析等新兴应用领域的迅速发展，对海量信息的有效利用提出了迫切的要求。我们正处于信息爆炸的时代，纷繁复杂的信息给人们理解、查询和获取知识带来沉重的负担。信息可视化通过对抽象信息提供计算机支持的、交互式的、可视化的表示形式，不断增强人们对于复杂信息的认知能力，成为人们解释现象、发现规律、辅助决策的强有力工具。 人机交互是信息可视化的重要研究领域。然而，对于信息可视化中的人机交互的研究仍存在以下挑战：一是传统的信息可视化研究主要关注数据转换过程并以可视编码为核心，缺乏从人的角度出发对任务进行全面分析，对于新出现的交互任务提供的理论支持不足，需要对传统信息可视化模型予以扩展。二是针对海量信息在小界面中的可视化与交互问题，如何为用户提供真正符合认知规律的新的交互式可视化技术，使用户能够高效地进行交互探索以洞悉知识。三是针对领域应用中的非专家用户需要构建具有个性化用户界面的交互式信息可视化系统的问题，如何提供一套统一的开发方法。本文正是从上述问题出发，围绕着信息可视化中的交互技术，从理论、方法与应用等方面展开研究。 本文首先论述了信息爆炸带来的挑战以及信息可视化的发展趋势，继而对信息可视化、人机交互、模型驱动架构等相关研究进行了综述。在此基础上构建了交互式信息可视化框架，建立了交互式信息可视化的用户界面模型IIVM。然后，针对海量信息在小界面中的可视化与交互问题，提出了嵌套圆鱼眼视图技术、基于嵌套圆鱼眼视图的Focus+Context交互式可视化技术、基于网络关注度模型的Focus+Context交互式可视化技术。针对非专家用户构建具有个性化用户界面的交互式信息可视化应用的问题，提出了基于模型IIVM的交互式信息可视化系统开发方法Daisy。最后，将上述研究成果应用于制造企业交互式信息可视化系统与计算机文件系统的开发，给出了两个应用实例。 本文的创新点主要包括： 1. 构建了一个交互式信息可视化框架。 本文在信息可视化的经典模型基础上对其进行扩展，构建了一个交互式信息可视化框架。该框架从用户、任务、信息三个方面对信息可视化进行描述，深入分析了信息的转换过程、任务的层次树模型、用户的认知规律，并讨论了三者之间相互影响的关系。该框架提炼了信息可视化中人的特征、计算机表示的信息的特征以及相互之间的关系，能够为信息可视化中的人机交互理论提供支撑。 2. 建立了交互式信息可视化的用户界面模型IIVM。 本文围绕着交互式信息可视化框架中的用户的特征、任务的特征、信息的特征及其相互之间的关系，基于Puerta提出的基于模型的界面开发通用框架中的界面模型，建立了交互式信息可视化的用户界面模型IIVM。讨论了IIVM的抽象组成元素即用户模型、任务模型、领域信息模型，以及具体组成元素即可视化表征模型与对话模型，建立了各个模型间的映射关系，并给出了IIVM的形式化定义。IIVM能够有效地描述具有个性化用户界面的交互式信息可视化系统。 3. 提出了两种新的Focus+Context交互式可视化技术。 针对海量信息在小界面中的可视化与交互问题，在认知心理学规律基础上，提出了嵌套圆鱼眼视图技术；提出了一种基于嵌套圆鱼眼视图的Focus+Context交互式可视化技术；提出了一种基于网络关注度模型的Focus+Context交互式可视化技术。实验结果表明：上述方法能够有效解决在小界面内对海量信息的交互式可视化的问题，具有较高任务完成效率和用户满意度。 4. 提出了一种基于模型的交互式信息可视化系统开发方法Daisy。 提出了一种基于模型IIVM的交互式信息可视化系统开发方法Daisy。描述了该方法的软件生命周期，论述了其中两项关键技术：IIVM建模与描述文件生成方法、系统自动生成方法。讨论了支撑该方法的Daisy平台的体系结构，给出了Daisy工具箱。实验表明，该方法可以为非专家用户构建交互式信息可视化的特定领域应用提供一种有效的解决方案。 5. 基于上述研究成果完成了制造业交互式信息可视化系统和计算机文件可视化系统等两个实际系统的开发。 将研究成果应用于两个系统。一方面，将Daisy方法及Focus+Context交互可视化技术应用于制造业领域，构建了制造业企业交互式信息可视化系统。实例表明，Daisy能够面向非专家用户、为交互式信息可视化系统的开发提供一种统一的解决方案。另一方面，将基于嵌套圆鱼眼视图的Focus+Context交互式可视化技术应用于计算机文件系统，开发了基于嵌套圆的计算机文件可视化系统。应用实例表明，本文研究成果既具有理论价值又具有应用价值。

面向网状信息的Radial+Focus可视化

针对当前网状信息可视化技术忽略了网状信息节点的可视信息的问题,提出一种面向网状信息的Radial+Focus可视化技术。首先介绍网状信息节点的信息详细度与先验重要度,并研究通过节点的交互历史计算节点的先验重要度的方法;然后研究了基于节点先验重要度的Radial+Focus布局算法;最后,给出了Radial+Focus可视化技术的应用实例和实验评估。实验评估表明,该技术能自然、高效地可视化网状信息,为用户对网状信息关系及网状信息节点的可视信息的分析提供有力的支持。

Atomic force microscopic study of low temperature induced disassembly of RecA-dsDNA filaments

The assembly and disassembly of RecA-DNA nucleoprotein filaments on double-stranded DNA (dsDNA) or single-stranded DNA (ssDNA) are important steps for homologous recombination and DNA repair. The assembly and disassembly of the nucleoprotein filaments are sensitive to the reaction conditions. In this work, we investigated different morphologies of the formed nucleoprotein filaments at low temperature under different solution conditions by atomic force microscopy (AFM). We found that low temperature and long keeping time could induce the incomplete disassembly of the formed nucleoprotein filaments.

Potential-induced transformation for surfactant aggregates on a metal surface

Surfactant adsorption on metal surfaces has been used to limit the activity of the electrode surface and to stabilize colloidal clusters and nanoparticles in solution, but the adsorption and relative potential-induced structure change of the surfactant were not known. Here, the adsorption of sodium dodecyl sulfate (SDS) on a Au(111) surface under potential control was investigated by in situ scanning tunneling microscopy (STM). The STM images showed that the morphology of SDS on Au(111) was changed from a hemi-cylindrical micellar monolayer to a compact and uniform bilayer through control of the potential. The transition between the hemimicellar monolayer and the compact bilayer is not reversed after a period of time. The model of potential-induced transformation for SDS aggregates on Au(111) was established. (C) 2001 Elsevier Science B.V. All rights reserved.

Induction and characterization of green pigmentation mutant in Porphyra yezoensis Ueda

The free living conchocelis of Porphyra yezoensis Ueda was treated with N-methyl-N-nitro-N-nitrosoguanidine to induce pigmentation mutants. The artificial green pigmentation mutant of P. yezoensis conchocelis, which was composed entirely of green cells, was isolated through visualization with the unaided eye. The acquired green conchocelis was further developed into a green gametophytic blade. This mutant was relatively stable in color in both gametophytic blade and conchocelis phases. The gametophytic blade mutant was successively cultivated for commerce at some Porphyra farms in Rudong, China, and few wild type or sectorially variegated gametophytic blade occurred, indicating that the green mutant has commercial value. The green mutant was characterized as having lower phycoerythrin and higher phycocyanin content, and SDS-PAGE suggested that phycoerythrin was missing the gamma-subunit in comparison to the wild type. The wild type and the green mutant showed a clear difference in 02 evolution rates in white, green, yellow, and red light, which might be due to the qualitative and quantitative changes of phycoerythrin, and the quantitative difference of phycocyanin. (C) 2008 Elsevier B.V. All rights reserved.

Fine-grained Pleistocene deepwater turbidite channel system on the slope of Qiongdongnan Basin, northern South China Sea

Recently, as oil exploitation has become focused on deepwater slope areas. more multi-channel high resolution 2D and 3D seismic data were acquired in the deepwater part of the Qiongdongnan Basin, northern South China Sea. Based on 3D seismic data and coherence time slice, RMS and 3D visualization, a series of deepwater channels were recognized on the slope that probably developed in the late Quaternary period. These channels trend SW-NE to W-E and show bifurcations, levees, meander loops and avulsions. High Amplitude Reflections (HARs), typical for channel-levee complexes, are of only minor importance and were observed in one of the channel systems. Most of the detected channels are characterized by low-amplitude reflections, and so are different from the typical coarse-grained turbidite channels that had been discovered worldwide. The absence of well data in the study area made it difficult to determine the age and lithology of these channels. Using a neighboring drill hole and published data about such depositional systems worldwide, the lithology of these channels is likely to be dominated by mudstones with interbedded thin sandstones. These channels are formed by turbidity currents originated from the little scale mountain river of mid-Vietnam in SW direction and were probably accompanied by a relative sea level drop in the last glacial age. These channels discovered on the northern South China Sea slope are likely to be fine-grained, mud-dominant and low N:G deposits in a deepwater paleogeographic setting. (C) 2009 Elsevier Ltd. All rights reserved.

基于数字制造环境的可重构装配线仿真分析平台

以某汽车变速箱装配生产线制造系统为背景,应用多Agent制造及Holon制造模式改造传统装配生产线以提升其柔性与重构能力·针对基于agent与holon混合思想的可重构装配生产线的基础框架与实现等理论提供分析验证环境,提出应用数字制造技术构建面向可重构装配线的数字仿真验证平台·在分析面向重构装配线的仿真平台功能特征的基础上,构建了数字仿真验证平台的框架·研究了仿真平台开发中的系统集成、可视化仿真、可重构装配线性能分析等关键技术,最后给出了仿真平台的实例系统·

基于Vega Prime的多水下机器人视景仿真系统的设计与实现

介绍了一套多水下机器人三维视景仿真系统。该系统采用虚拟现实技术，利用虚拟仿真软件VegaPrime 与Visual C++.NET 2003 混合编程实现三维视景仿真。它主要用于海洋环境的模拟和多水下机器人运行时的位姿更新、碰撞检测、环境效果及各种特效的实时显示。此外，它还具有响应各种输入/输出设备的功能和通过人性化图形界面接口与用户进行交互的功能。

一种模糊petri网仿真工具的设计实现

文章将面向对象思想应用于模糊Petri网仿真工具的设计和实现过程,探讨了模糊Petri网建模与仿真的可视化问题,提出了基于网格可视化技术解决方案及具体实现方法。通过对变速箱的自动建模和诊断仿真实例,证明该系统具有良好的实用性,为模糊Petri网理论的普遍应用提供了工具平台。

辽河坳陷东部凹陷火山岩构造裂缝形成机理研究及预测

In recent years, with the discovery oil and gas reservoirs in volcanic rocks, the exploration and development of these reservoirs have attracted widespread attention because of the urgent need for increasing oil and gas production in the world and volcanic rocks has currently become an important exploration target in Liaohe depression. The study area of this dissertation is in the middle section of the easternern sag of Liaohe depression that have been confirmed by studying structural fractures, which constitute a key factor impacting volcanic rocks reservoirs. Substantial reserves and large production capacity in the areas with widely distributed volcanic rocks are important reasons for examining volcanic rocks in the study area. The study began with classification and experimental data analysis of volcanic rocks fractural formation, then focused on the mechanism of fracturing and the development of volcanic rocks structural fracture prediction methodology.and Lastly, predicted volcanic rocks structural fracture before drilling involved a comprehensive study of the petroleum geology of this area, which identified favorable traps thereby reducing exploration risks and promoting the exploration and development of volcanic rocks reservoirs. 3Dstress and 3Dmove software were applied to predict structural fracture by combining the core data, well-logging data and seismic data together and making the visualization of a fracture possible. Base on the detailed fracture prediction results, well OuO48 and well Ou52 were drilled and successfully provided a basis for high efficiency exploration and development of fractured reservoir in the middle section of the eastern sag. As a result of what have been done, a new round of exploration of volcanic rocks was developed. Well OU48 and well OU52 successfully drilled in this area resulted in the in-depth study of the mechanism of structural fracture formation, technological innovation of structural fracture prediction of volcanic rocks , which guided to oil and gas exploration effectively and made it possible for high production of volcanic rocks. By the end of August 2005, the cumulative oil and gas production of Ou48 block were 5.1606 × 104 t and 1271.3× 104 m3 respectively, which made outstanding contributions to the oilfield development. Above all this work not only promoted exploration and structural fracture prediction in volcanic rocks in Liaohe depression, but also applied to in the low-permeability and fractured sandstone reservoir.