基于STL模型的逆向工程实体建模技术

针对以STL数据表示的零件模型，在分析结构件模型几何特点的基础上，提出了一种以几何体素分离与拓扑关系重建为基础的STL模型逆向工程实体建模技术。通过对三角面片的合并实现平面、柱面、锥面等基本几何体素的分离，并利用Parasolid系统完成体素重构，进一步提取几何体素之间的布尔关系，从而实现含拓扑关系的产品模型重构。利用这一方法，可以实现RE／RP系统与通用CAD系统之间的快速集成，实现产品数据在不同系统之间顺畅传递。     

注塑模CAE用实体模型的表面网格模型生成方法

为了实现注塑模CAE软件与商用CAD软件之间的数据交换，给出了基于STL文件的三维实体模型的表面有限元网格划分方法。该算法利用STL文件传递薄壁注塑件的实体模型信息，在对该模型的表面区域进行合并的基础上，重新进行网格划分，可生成质量较好的表面三角形网格，从而得到满足成型模拟需要的有限元网格模型。     

面曝光3D打印的STL模型快速切片系统

为了提高STL模型切片轮廓填充的准确度,设计了基于体素信息的STL模型快速切片系统。介绍了面曝光3D打印机的工作步骤,并分析了STL模型切片处理中存在的问题。依据STL模型的体素信息优化填充结果,解决了交替填充方案带来的填充错误;针对拼接面曝光3D打印的需求扩展系统功能,并采用可配置的思想设计软件。实验证明该系统提高了切片结果的准确度,适用于拼接面曝光3D打印场景,具备可扩展、可复用性,有较高的实际应用价值。     

基于OpenGL技术的STL数据格式的显示

通过利用OpenGL图形编程工具和Visual C++6.0编程语言,详细介绍了如何读取以及显示STL文件的方法。比较详尽地介绍了STL数据文件的格式,在实现显示的基础上,进一步地讲述了使用OpenGL如何拓展软件的一些其他功能。     

STL技术在构造专家系统知识库中的应用

介绍了STL(C++标准模板库)的基本内容和特点,并使用STL组件和算法构造了一个专家系统知识库,能有效地存储和管理知识,体现了STL技术的高效性和灵活性。     

基于STL的注塑模CAE前处理系统的实现

通过对STL进行表面模型重整、超面的网格划分等操作完成对三维实体(塑料制品)的表面三角网格划分,辅以节点配对等操作形成注塑模CAE有限元分析的前处理数据。     

丙交酯接枝淀粉提高聚乳酸/淀粉共混物透明性的研究

合成了丙交酯接枝淀粉(STL),采用红外光谱(FTIR)和核磁共振(NMR)表征了其结构。分别制备了聚乳酸(PLA)与塑化淀粉(TPS)、马来酸酐改性淀粉(MTPS)、STL质量比为90/10、70/30、50/50的熔融共混物,通过扫描电子显微镜(SEM)、雾度、透光率和拉伸测试表征了共混物的微观形貌、透明性和力学性能。结果表明:PLA/STL共混物中淀粉分散相尺寸更小,透明性与力学性能均明显大于PLA/TPS和PLA/MTPS。PLA/STL(90/10)共混物的透光率达到72.3%,力学性能接近纯PLA。     

除尘设备叶片的三维扫描和3D打印优化

以有内部结构和曲面的除尘设备叶片为例,以三维扫描仪扫描图像为基础,先用Power Scan作系统标定,然后扫描,之后用Geomagic对模型进行优化处理,导出STL文件,在idea Maker中对模型作旋转、分割进行3D打印。在模型的扫描与打印过程中,会产生一系列的缺陷,针对扫描与打印过程中的缺陷进行优化分析,并最终获得合理的模型。     

基于CopyCAD的逆向工程

逆向工程是近几年迅速发展起来的一门新兴学科。首先,对需要再设计的产品实物进行三维数字化处理,然后将获得的三维离散数据作为初始素材,借助专用的曲面处理软件和CAD／CAM系统构造实物的CAD模型,输出NC加工指令或用STL文件驱动快速成型机制造出产品或原型。DELCAM以CopyCAD核心的逆向工程解决方案是集逆向工程、CAD／CAM为一体的完整的实现逆向和再设计的完整解决方案。     

罗茨风机流量控制算法的实现与应用

介绍了三叶罗茨风机的工作原理、流量控制原理以及使用几何方法求解指定转速下流量的过程.给出了实际应用方法,并针对文中相应的公式给出了具体的STL语言实现过程.     

泛型编程及STL在内存数据库中的应用

泛型编程是一种新的编程思想,它基于模板技术,有效地将算法与数据结构分离,降低了模块间的耦合度。STL(standardtemplatelibrary)是采用泛型编程思想设计的类库,其涵盖了常用的数据结构和算法,并且具有跨平台的特点。将泛型编程思想和STL库用于内存数据库系统的设计中,降低了开发强度,提高了程序的可维护性及代码的可重用性。     

油页岩与煤路线制油的技术经济分析和比较

液体燃料广泛应用于交通、物流和生活等行业,然而液体燃料的生产严重依赖石油。我国石油资源相对贫乏,石油对外依存度高达60%。为减少对石油的依赖,我国正积极开发石油替代资源,特别是油页岩和煤炭。但迄今少有文献报道对油页岩与煤路线生产液体燃料过程进行全面的技术经济分析和比较。本文通过对油页岩制油和煤制油分别进行建模和模拟,根据模拟从能效、投资和成本等方面对这两种路线进行分析和比较。结果表明油页岩制油的能效比煤制油低5个百分点,因为油页岩制油的原料利用率低,产品收率低。经济方面,油页岩制油的固定投资为63.34元/GJ,相比煤制油节省70%,因为油页岩制油流程短,设备结构简单。但油页岩制油的原料消耗大,生产1t液体燃料消耗24.5t油页岩,所以其成本相比煤制油仅节省6%。     

双通道平板型环路热管的传热特性

以铜为主要材料、超纯水为工质研发了双通道平板型环路热管。分别在双通道环路热管的两根液管上安装阀门,通过阀门的开关,实现双通道平板型环路热管和单双道平板型环路热管的互相转换。通过实验,发现双通道平板型环路热管的传热性能比单通道平板型环路热管要好。在热源的加热量为30W时,蒸发器温度的降幅可达10℃。在不同的功率下,双通道环路热管比单通道环路热管总热阻的下降幅度在20%以上。但双通道平板型环路热管的总热阻与单通道平板型环路热管相比,降幅并没有达到50%,这是由于采用双通道的形式,只能减小通道压降造成的热阻以及冷凝热阻,但不能减小蒸发器热阻。     

煤热解制油和油页岩制油技术评述与比较分析

近年来，以煤热解为龙头制燃料油和油页岩制燃料油作为战略储备能源生产路线得到了快速的发展。评述和比较了典型煤热解制油与油页岩制油技术。对比分析表明：生产每吨燃料油，需消耗11.4 t低阶煤或24.5 t油页岩。煤热解制油水耗是油页岩制油的1.4倍。经济方面，煤热解制油和油页岩制油投资分别为6510和5716元/吨燃料油；生产成本分别为3887和4217元/吨燃料油；通过计算不同原料价格下相对于国际原油价格的盈亏平衡点，得出煤热解制油和油页岩制油的盈亏平衡点分别在59~68 USD·bbl^-1和71~76 USD·bbl^-1之间变化。煤热解制油和油页岩制油路线各有优劣，仍需完善相关技术和延伸产业链，可从干馏炉、系统集成、综合利用、多联产等方面寻求突破。     

Experimental and theoretic studies on sound transmission loss of laminated mica‐filled poly(vinyl chloride) composites

The effects of dioctyl phthalate and inorganic filler, mica, on the sound insulation property of poly(vinyl chloride) (PVC) were investigated in this work. The stiffness and mass laws, which are the common theoretic tools to predict the soundproof properties of materials, were used to analyze the sound transmission loss (STL). The experimental results revealed that the stiffness and mass laws can describe well the sound insulation property of PVC/mica composites. The stiffness and surface density are important factors influencing the improvement of STL. With the increase of content of mica, STL and resonance frequency, f_mn, of PVC/mica composites increase. Moreover, the change of STL in the stiffness‐ controlled region is more obvious than that in the mass‐controlled region, because the addition of mica in PVC leads to a greater increase in the stiffness. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Differentiation of human promyelocytic leukemia cell line HL60 by microbial extracellular glycolipids

Microbial extracellular glycolipids, succinoyl trehalose lipid (STL), and mannosylerythritol lipid (MEL) inhibited the growth of a human promyelocytic leukemia cell line, HL60, and induced their morphological changes. The results of specific and nonspecific leukocyte esterase activities showed that STL induced monocytotic differentiation while MEL induced granulocytic differentiation. STL and MEL markedly increased common differentiation-associated characteristics in monocytes and granulocytes, such as nitroblue tetrazolium (NBT) reducing ability, expression of Fc receptors, and phagocytic activities in HL60 cells, respectively. Neither sugar moieties nor fatty acids in the free form, the individual components of STL and MEL, were effective at inducing the differentiation of HL60 cells. The induction of differentiation was not due to surface activities of STL and MEL on the basis of the complete ineffectiveness of the analogues tested. The composition of cell surface glycosphingolipids (GSL) changed such that the G_M3/LacCer ratio increased in STL-treated cells, whereas it decreased in MEL-treated cells. HL60 cells treated with STL and MEL exhibited a significant decrease in the activity of the intracellular phospholipid- and Ca²⁺-dependent protein kinase (protein kinase C). Furthermore, the serine/threonine phosphorylations in intact HL60 cells were clearly inhibited by the presence of G_M3 and MEL, but not by LacCer and STL. These results suggest that the differentiation-inducing activity of STL and MEL is not due to a simple detergent-like effect but due to a specific action on the plasma membrane. The inhibitory effect of STL on protein kinase activity was through increasing G_M3, but MEL had a direct inhibitory effect.     

SiC and SiOC ceramic articles produced by stereolithography of acrylate modified polycarbosilane systems

3D printed ceramic articles are receiving increased interest recently. Stereolithography (STL) is the method of choice where surface quality, high resolution and high aspect ratio architectures are concerned. Recently, we have developed a UV curable system consisting of allylhydridopolycarbosilane (AHPCS) and multifunctional acrylates. In our present work we investigate the photo-crosslinking mechanism and use selected formulations for the 3D printing of SiC rich ceramic articles using a desktop STL device. High resolution and complex shape articles are demonstrated. The versatile curing method can be used for the STL of practically most other vinyl/allyl modified preceramic polymers. The nano-porosity as well as SiOxCy composition can be tailored in a wide range for specific applications by the ratio of acrylate to AHPCS and by the type of acrylate and AHPCS used.     

Graphene nanopatterns with crystallographic orientation control for nanoelectronic applications

The possibility of parallel processing of several features was investigated experimentally for the two methods allowing the crystallographically controlled nanopatterning of graphene: scanning tunneling lithography (STL) and carbothermal etching (CTE). It was found that with multitip systems both methods are suitable for parallel processing. CTE has the advantages that only in the atomic force microscope (AFM) indentation phase is needed the multitip system and it can reveal the location of grain boundaries, so that the nanodevices can be placed in a way that they do not cross grain boundaries. STL is well suited for purposefully producing twisted graphene multilayers with precisely-know misorientations of the individual layers, as also evidenced by Moiré-type patterns observed in the atomic resolution scanning tunneling microscopy (STM) images.