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Reconstruction of curved solids from engineering drawings 总被引:6,自引:0,他引:6
This paper presents a new approach for reconstructing solids with planar, quadric and toroidal surfaces from three-view engineering drawings. By applying geometric theory to 3-D reconstruction, our method is able to remove restrictions placed on the axes of curved surfaces by existing methods. The main feature of our algorithm is that it combines the geometric properties of conics with affine properties to recover a wider range of 3-D edges. First, the algorithm determines the type of each 3-D candidate conic edge based on its projections in three orthographic views, and then generates that candidate edge using the conjugate diameter method. This step produces a wire-frame model that contains all candidate vertices and candidate edges. Next, a maximum turning angle method is developed to find all the candidate faces in the wire-frame model. Finally, a general and efficient searching technique is proposed for finding valid solids from the candidate faces; the technique greatly reduces the searching space and the backtracking incidents. Several examples are given to demonstrate the efficiency and capability of the proposed algorithm. 相似文献
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以安徽怀远石榴和滁州贡菊为主要原料,将所得的石榴果汁与菊花浸提液进行调配,通过正交试验,制得一种既有石榴的酸甜口味又有菊花香味的果汁茶饮料.其配方为:菊花浸提液40%、石榴果汁20%、白砂糖12%、柠檬酸0.10%. 相似文献
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A Survey of Visual Analytics Techniques and Applications: State-of-the-Art Research and Future Challenges 下载免费PDF全文
Visual analytics employs interactive visualizations to integrate users’ knowledge and inference capability into numerical/algorithmic data analysis processes.It is an active research field that has applications in many sectors, such as security, finance, and business.The growing popularity of visual analytics in recent years creates the need for a broad survey that reviews and assesses the recent developments in the field.This report reviews and classifies recent work into a set of application categories including space and time, multivariate, text, graph and network, and other applications.More importantly, this report presents analytics space, inspired by design space, which relates each application category to the key steps in visual analytics, including visual mapping, model-based analysis, and user interactions.We explore and discuss the analytics space to add the current understanding and better understand research trends in the field. 相似文献
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重烷基苯磺酸盐在大庆油砂上的静态吸附损失研究 总被引:10,自引:1,他引:10
研究了在地层温度(45℃)下,重烷基苯磺酸盐(HABS)以及以其为主表面活性剂的配方物在大庆油砂上的静态吸附损失。结果表明,HABS由于具有较大分子截面分积和含有对电解质敏感的高摩质量成分,自纯水溶液中的吸附量较小,而自NaOH溶液中的吸附量显著增加。HABS自0.8g/dL NaOH溶液中的吸附符合Langmuir吸附,饱和吸附量为2.39mg/g油砂。HABS自0.6-1.2g/dL Na3PO4和Na2SiO3溶液中的吸附量为0.5-0.9mg/g油砂,约为自NaOH和Na2CO3溶液中的吸附量的三分之一。加入少量耐盐性表面活性剂如AES以及采用NaOH/Na3PO4复合碱有利于降低HABS的吸附量。以HABS为主表面活性剂的配方物自纯水溶液、1.0g/dL NaOH溶液和1.0g/dL Na3PO4溶液中的吸附量分别小于、相当于以及小于表面活性剂ORS-41相应吸附量。溶液中含有聚合物有利于降低表面活性剂的吸附损失。 相似文献
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