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991.
992.
采用相转化纺丝/烧结技术制备Al2O3多孔中空纤维膜,并以此为载体,通过晶种法考察不同晶种诱导条件制备TS-1复合中空纤维膜,并采用扫描电子显微镜、气体渗透性能测试装置等设备对所制备的TS-1复合中空纤维膜进行微观结构及渗透性能的表征。结果表明,晶种法制备的TS-1复合中空纤维膜的N2渗透速率较小,并且表面平整无缺陷,因此该方法适合制备性能优良的TS-1复合中空纤维膜。 相似文献
993.
《Journal of Cultural Heritage》2014,15(5):479-489
This study proposes a procedure for digitally classifying and cataloging moulds which belong to the historic collection of the Ginori porcelain factory in Doccia (Sesto Fiorentino, Italy). In addition to a vast number of antique plaster moulds, this collection includes artistic porcelain artifacts obtained from casting porcelain using the moulds and models made of various materials. The proposed methodology includes two workflows: the first starts with photographic and casting processes conducted recently on various groups of moulds and involves historical surveys for investigating the relationships between the various sets of moulds, the models from which they were derived and the porcelain objects derived from them. The second workflow was applied when no information was available for a set of moulds, and involved 3D scanning of the moulds, with virtual reconstruction of the corresponding model followed by a final art historical survey like that used in the first procedure. 3D scanning techniques and successive model reconstruction can also be applied for obtaining a virtual model in the first process, when the physical model was lost, damaged or never existed. The variety and extent of the Ginori collection suggested the use of a customized Data-Base (DB) and a set of functions designed to manage and extract information, data and archived images. This filing system, called DocciaDigitalArchive (DDA), also makes it possible to specify the relationships between the different typology samples (prototype models, moulds derived from them, handmade porcelain objects produced from these moulds), which are associated when the same subject is portrayed. The DB structure conceived also provides the possibility of incorporating pictures and data of known archetypes. This additional information makes it possible to place each subject in its historical and artistic context. For each sample filed in the DDA system, documentary cards, which summarize data, images, reports and links to other entities or samples connected to the subject consulted, can be viewed on a suitable interface. 相似文献
994.
《Journal of Cultural Heritage》2014,15(2):196-198
In most cases, the polychrome paintings that decorated heritage buildings no longer exist or are reduced to mere remnants. These facts decontextualize the sites in their historical and artistic evolution, distort the intention under which they were conceived, and hamper their accomplishment. Current recovery methods are restricted to the stabilization of the remains in their present status, requiring a lot of completely manual work that is expensive and almost unrelated to the use of new technologies. Three-dimensional digitalization and modelling is proved to be the basis for the virtual recovery of paintings in a significant edifice. To do so, an innovative methodology is presented that allows the 3D geometric information of a site (captured using a laser scanner) to be combined with specially designed 2D artistic images. The resulting 3D digital models can then be focused, with high efficiency projectors, on the equivalent area of the original site, and also used as raw material to compose a video-projection without perspective effects to emulate, with due rigour, the primitive appearance, its evolution along time, the effects of the deterioration, or other interesting aspects. The results obtained at Sta. María de Mave (Palencia, Spain) are presented, supporting the potential of this new methodology not only as a scientific way to discuss possible restoration hypotheses with experts or as a didactic tool for narrating the historical evolution of a monument, but also as a spectacular show for tourists. 相似文献
995.
Biotechnology firms operate in a high-risk and high-reward environment and are in a constant race to secure venture capital (VC) funds. Previous contributions to the literature show that the VC firms tend to invest locally in order to monitor their investments and to provide operating assistance to their target firms. Further, biotechnology is a knowledge-based industry that tends to exhibit spatial clusters, and the firms in such industries may collocate to benefit from gaining access to local markets for specialized inputs (e.g., skilled researchers) and from local knowledge spillovers and network externalities. If such gains exist, we expect that the collocated firms should exhibit positively correlated performance, including in their ability to attract venture capital funds. The purpose of this paper is to empirically measure the strength and spatial extent of the relationships among the amount of funds raised by proximate biotechnology firms. We model these relationships with a spatial autoregression (SAR) model, and we control for characteristics of the biotechnology firms and the VC firms that provide their funds as well as site-specific factors. Based on our fitted SAR model, we find that the amount of venture capital raised by a particular biotechnology firm is significantly influenced by the number of VC firms and the VC funding levels raised by biotechnology firms located within a 10-mile radius, but these relationships are not statistically significant beyond this range. 相似文献
996.
997.
2009年是中国3G元年,在这一年,我国三大移动通信运营商的3G网络将正式投入商用,中国移动通信领域也将随之步入3G时代。随之而来的是3G手机的大量普及,使人们的生活变得丰富多彩起来,可视电话、手机电视、高速上网、电话会议、刷卡支付成为了可能。 相似文献
998.
描述一种脑白质纤维三维重建显示方法。该方法采用DW-MRI数据,由Streamline纤维跟踪算法生成脑白质纤维节点数据:利用ActiViz.NET实现VTK(The Visualization Toolkit)在.Net平台上的调用,通过数据导入、映射、渲染、刷新显示等流程完成三维可视化显示。该方法实现基于.Net平台,利用C#语言完成所有代码编写。本方法实现的三维重建显示,功能强大、使用灵活,具有步骤清晰简单、效果好、速度快、交互能力强等优点,可以被广泛应用于脑医学图像的重建中。 相似文献
999.
数字铁路的建设需要解决勘察设计、建设施工、运营养护三大阶段的信息共享、综合利用问题。通过分析数字铁路的主要研究内容及关键技术,阐述了数字铁路信息共享体系的构建,以及对建设数字铁路具有的重要指导意义。 相似文献
1000.
用改进威胁模型规划后的电势理论划出实用的三维航迹.对有地形威胁和雷达、火力威胁的各种情况进行了分类、分析,并推出计算公式.通过限定搜索范围为包含起始点和目标点之间的矩形区域,不但减少了计算的复杂度,而且保证飞行路线收敛于目标点.用坡度限制平滑算法和用曲率限制平滑算法对上述航迹的法向加速度和曲率进行约束,得到符合飞行器机动性的飞行路线. 相似文献