一种制做三维牙——颌骨光弹性模型的新方法

本文提出一种用“整体浇注法”制做三维牙——颌骨光弹性模型的新方法,即用价格便宜的石膏做阴模,先制出与真实牙几何相似的牙光弹性模型和模拟牙周膜的乳胶套,将它们粘接好,然后将其放入颌骨石膏阴模的适当位置,浇入环氧树脂混合液,用“二次固化法”进行固化,即可制成三维牙——颌骨整体光弹性模型。此法能保证模型与实物的严格几何相似和牙周的边界条件相似,使实验精度大大提高且工艺简单、成本低。     

A portable stereo vision system for whole body surface imaging

This paper presents a whole body surface imaging system based on stereo vision technology. We have adopted a compact and economical configuration which involves only four stereo units to image the frontal and rear sides of the body. The success of the system depends on a stereo matching process that can effectively segment the body from the background in addition to recovering sufficient geometric details. For this purpose, we have developed a novel sub-pixel, dense stereo matching algorithm which includes two major phases. In the first phase, the foreground is accurately segmented with the help of a predefined virtual interface in the disparity space image, and a coarse disparity map is generated with block matching. In the second phase, local least squares matching is performed in combination with global optimization within a regularization framework, so as to ensure both accuracy and reliability. Our experimental results show that the system can realistically capture smooth and complete whole body shapes with high accuracy.     

Effects of age and gender on maximum voluntary range of motion of the upper body joints

The maximum voluntary range of motion (ROM) of the major joints of the upper body was studied in a seated position and compared between young and elderly subjects. A total of 41 subjects (22 young male and female subjects aged 25 to 35 years, 19 elderly male and female subjects aged 65 to 80 years) took part in the experiment. In total, 13 maximum voluntary joint motions were performed by each subject. Age was found to have a non-uniform effect on the ROM of the joints investigated in this study. Its effect on ROM was joint specific and motion specific. The highest loss in ROM was observed in the neck and trunk, especially for neck extension, lateral flexion and axial rotation as well as for trunk lateral flexion and axial rotation. No significant age differences were observed in the elbow and wrist joint ROMs. The effect of gender on joint ROM was much weaker than that of age. Only four among the 26 joint ROMs investigated in this study were significantly different between the two gender groups.     

In-plane directional mechanical properties of carbon fabric skins in sandwich structures after thermoforming

In this paper, a representative unit volume finite element (RUV FE) model was employed to simulate thermoforming process of carbon fabric-polymeric foam sandwich structures. Thermoforming simulations, which capture crimp angles and amplitude changes of carbon fabric with respect to different operational pressure, were conducted with the help of RUV FE model. Micro-deformation of tow structures after thermoforming was rigorously reflected in the second stage FE model to determine the in-plane directional stiffness of skin parts. Tensile tests were carried out to investigate mechanical properties of skin parts in sandwich structures for the potential usage of automotives, electronic housings or the satellite structure design.     

面板堆石坝下游坝坡稳定可靠度分析

应用考虑条块间水平作用力的条分法，在非线性破坏准则的基础上，结合堆石面板坝的破坏模式，构造了完整的面板堆石坝下游坝坡稳定可靠度分析模型，并结合实例进行了计算．所得结果合理，表明该模型比较符合实际．     

微细粒浸染型金矿碱性介质浮选法研究

介绍了微细粒浸染型金矿石浮选富集的一种新方法———以碳酸钠作为pH调整剂的碱性介质浮选法,并研究了这种方法浮选富集矿石过程中各种因素的影响。研究表明,在弱碱性矿浆中(pH值7 5～8 5)能够较好地实现载金矿物与脉石矿物的浮选分离。     

鞍钢3200m3高炉矿槽施工

介绍了鞍钢新1号高炉(3200m3)矿槽结构的设计原理及其所包含的钢结构、混凝土结构施工技术要点和质量控制,并作出了技术经济效果评述.     

甘肃某金矿选矿试验研究

根据国内某金矿载体矿物的性质,进行了详细的选矿条件试验,获得了较优的工艺参数,最终确定了“一粗两精两扫,中矿顺序返还”的工艺流程。闭路试验结果表明：在磨矿细度为一0．074mm占70％的条件下,可获得产率2．89％、品位85．16g／t、回收率82．17％的金精矿。     

铁尾矿为原料微波法制备介孔分子筛

以鞍山铁尾矿为硅源,CTAB为模板剂,采用微波辐照法合成出全硅介孔分子筛MCM-41。用N2低温吸附、FT-IR、XRD和TEM等表征手段考察了其比表面积、孔径分布、晶体形貌等特性。结果表明:微波辐射法合成的MCM-41分子筛诱导期极短,晶化速度很快,具有典型的按六方对称性排列的孔道结构,FT-IR证明了分子筛具有硅氧四面体骨架。     

氧化锰矿直接浸出制备硫酸锰的几个影响因素

根据云南建水锰矿一年多来的生产实践，就氧化锰矿直接浸出制备硫酸锰工业生产的几个影响因素，进行了探讨并提出了提高浸出回收率的措施。