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71.
神木钢管拱桥钢结构制作技术 总被引:2,自引:2,他引:0
介绍神木钢管拱桥的结构特点和制作方法。为保证产品质量要求,神木钢管拱桥严格执行TB10212—98《铁路钢桥制造规范》,依据焊接评定工艺确定合理的焊接坡口及焊接方法;其次,设计并制造符合结构特点的工装设备,以及严格地执行检测方法,是钢管拱桥制造成功的必要措施。 相似文献
72.
73.
A videogrammetric as-built data collection method for digital fabrication of sheet metal roof panels
A roofing contractor typically needs to acquire as-built dimensions of a roof structure several times over the course of its build because a structure is never built to the exact drawing dimensions. In the construction phase and in order to digitally fabricate sheet metal roof panels, the contractor has to measure end-to-end dimensions of boundaries of every roof plane with a certain level of accuracy (i.e., errors less than ±2 cm). This is necessary to be able to cut sheet metal coil such that different pieces perfectly fit together. Obtaining these measurements using the exiting roof surveying methods could be costly in terms of equipment, labor, and/or worker exposure to safety hazards. This paper presents a video-based surveying framework as an alternative method which is simple to use, automated, less expensive, and safe. When using this framework, the contractor collects video streams with a calibrated stereo camera set. The captured data is processed to automatically generate a 3D wire-diagram of the target roof. Measurements from the wire-diagram are saved in a digital file (XML format) which could be loaded into an on-site sheet metal folding and cutting machine. Experimental analyses demonstrate applicability of the proposed framework. 相似文献
74.
2013年4月7日至10日,第八届IEEE国际纳米/微米工程及分子系统大会(IEEE-NEMS 2013)在中国苏州市召开[1-2],来自世界各地的360多位专家、学者齐聚一堂,就微纳研究领域的微/纳米制造和计量、微/纳米传感器、执行器和系统、纳米医学、微/纳流体、生物芯片、纳米材料、碳纳米管、石墨烯器件、微纳传热器件、能量采集器等多个方向展开了学术讨论和交流,充分展示了国内外在以上研究领域的最新研究成果、热点和动态,并对其发展趋势进行了分析。NEMS 2013国际会议的成功举办表明,以微/纳米分子系统等为代表的研究领域已成为高科技的重要代表,并极大地影响着世界的发展和人类生活。 相似文献
75.
吕毓军 《锻压装备与制造技术》2017,52(3)
立柱、工作台和滑块是折弯机关键零件,其强度和刚性对机床精度影响至关重要。通过分析立柱、工作台和滑块的结构及受力状况,提出一种多层分体组合结构,代替整体焊接结构,降低单件外形和重量,达到便于加工、运输和安装的效果。通过实际使用验证得出多层分体结构是折弯机尤其是大吨位折弯机大件理想的结构方式。 相似文献
76.
Hamed Safajou Mojgan Ghanbari Omid Amiri Hossein Khojasteh Farzad Namvar Sahar Zinatloo-Ajabshir Masoud Salavati-Niasari 《International Journal of Hydrogen Energy》2021,46(39):20534-20546
Recently, nanocomposite photocatalysts based on semiconductors have attracted much attention due to their suitable bandgap. Combination of tow of several semiconductors can slow down the electron-hole recombination. In this regard, we have depicted an eco-friendly and green fabrication technique to synthesize RGO/Cu nanocomposite by the reduction of graphene oxide and Cu2+ ion utilizing spearmint extract as a reductant and capping agent. The sample was identified by FTIR, XRD, FESEM, EDS, HRTEM, and CV. The results of photocatalytic performance revealed that RGO/Cu is an efficient catalyst for degrading organic pollutants. This compound can eliminate Rhodamine B (RhB) and Methylene blue (MB) 91.0% and 72.0%, respectively. 相似文献
77.
Defect detection is a critical measurement process for intelligent manufacturing systems to provide insights for product quality improvement. For complex products such as integrated circuit wafers, several types of defects are usually coupled in a piece of wafer to form a mixed-type defect, which poses a challenge to current defect detection methods. This paper proposed a knowledge augmented broad learning system with a knowledge module and broad selective sampling module, which provides a multichannel selective sampling network to decouple the mixed-type defects. In this model, each channel is equipped with a pre-trained deformable convolution model to extract the feature of a fixed single-type defect. The knowledge module is designed to activate the candidate network channel by pre-detection of wafer maps. The experiment results indicated that the proposed model outperforms conventional models and other deep learning models, which demonstrated that the knowledge augmented broad selective sampling mechanism is effective for mixed-type defect detection. 相似文献
78.
《International Journal of Hydrogen Energy》2022,47(16):9735-9743
A new production technique consisting mainly of a combination of tape casting and isostatic pressing to fabricate microtubular supports for solid oxide fuel cells is presented in this study. For this purpose, thin anode support layer is obtained by tape casting. The tape is then wrapped around a rod and subjected to isostatic pressing. The anode support microtube laminate is sintered after the removal of the rod. Microstructural observations show that the anode support with the suggested method is free of delamination and structural defect. Similar microtubular supports are also fabricated by conventional extrusion to compare the mechanical performance. Three point bending test results indicate that the anode supports with the suggested method provide higher mechanical strength due to improved compaction by isostatic pressing. Furthermore, similar microtubular cells are constructed on both anode supports for the electrochemical considerations. The results reveal that the cell, whose anode support is manufactured via tape casting and isostatic pressing, provides a reasonable electrochemical performance although no optimization is carried out in the fabrication steps. Therefore, the method recommended in this study is found to be an appropriate method for the fabrication of tubular/microtubular supports in solid oxide fuel cells or in similar areas. 相似文献
79.
Traditional preparation of superhydrophobic absorbents relies on solvents or further modification with silane. For environmental reasons, it is ideal to find ways that reduce or completely non-solvent. Herein, we show that superhydrophobic sponges can be obtained without solvents by the foaming process. Rough surface morphology and low surface energy were achieved simultaneously during the formation of superhydrophobic foam without further modification. The time required for oil–water separation was shortened significantly, when combined the sponge with a vacuum system. Importantly, the obtained sponge can retain its high oil absorption capacity after several cycles of oil–water separation. The sponge is easy to be scaled up and we have fabricated foams in large scale (37 cm × 30 cm × 22 cm) for making it an ideal candidate for practical application. 相似文献
80.
《Journal of the European Ceramic Society》2020,40(14):4837-4843
Fused filament fabrication (FFF), as one of the additive manufacturing technology, provides cost-effective and relatively fast preparation of 3D objects of desired dimensions and design. In this work, a composite filament containing 50 vol. % of sub-micron alumina powder was successfully used for the manufacturing of samples with prismatic design. The influence of the layer thickness (0.1–0.3 mm) on the final bulk density and mechanical properties were investigated. Sintering at 1600 °C for 1 h results in relative densities ranging from 80 to 89 % and the flexural strength reached 200–300 MPa depending on the layer thickness used for the printing. 相似文献