Beijing University of Technology , also called Beijing Polytechnic University or Bei Gong Da , is recognized as one of the Project 211 universities. The University has established a multidisplinary academic structure, offering a variety of programs and is involved in diversified research in the fields of Science, Engineering, Economics, Management, Liberal Arts, and Law. Wikipedia.
Zheng K.,Beijing University of Technology
Nature communications | Year: 2010
Glasses are usually shaped through the viscous flow of a liquid before its solidification, as practiced in glass blowing. At or near room temperature (RT), oxide glasses are known to be brittle and fracture upon any mechanical deformation for shape change. Here, we show that with moderate exposure to a low-intensity (<1.8×10(-2) A cm(-2)) electron beam (e-beam), dramatic shape changes can be achieved for nanoscale amorphous silica, at low temperatures and strain rates >10(-4) per second. We show not only large homogeneous plastic strains in compression for nanoparticles but also superplastic elongations >200% in tension for nanowires (NWs). We also report the first quantitative comparison of the load-displacement responses without and with the e-beam, revealing dramatic difference in the flow stress (up to four times). This e-beam-assisted superplastic deformability near RT is useful for processing amorphous silica and other conventionally-brittle materials for their applications in nanotechnology. Source
Beijing University of Technology | Date: 2013-03-13
A heat treatment process of high-Mg Er-containing aluminum alloy cold-rolled plates resistant to intergranular corrosion is disclosed, which belongs to the field of non-ferrous metals. The mass percentage of each component of high-Mg Er-containing aluminum alloy heat-rolled plates is, respectively, 5.8%-6.8% of Mg, 0.4%-0.8% of Mn, 0.15%-0.25% of Er, 0.15%-0.25% of Zr, the unavoidable impurities content being less than 4%, the balance being Al. The alloy hot-rolled plates are cold-rolled until the final cold deformation being 75%-90% after the intermediate annealing; the aluminum alloy cold-rolled plates undergo a stabilization annealing at the annealing temperature of 235 C. to 245 C. for 3.5-4 hours, and then is cooled in air to room temperature. This process significantly improves the resistance to intergranular corrosion while it does not reduce the strength of the alloy significantly.
Beijing University of Technology | Date: 2015-01-23
The present invention discloses a method for retrieving a similar image based on visual saliencies and visual phrases, comprising: inputting an inquired image; calculating a saliency map of the inquired image; performing viewpoint shift on the saliency map by utilizing a viewpoint shift model, defining a saliency region as a circular region which taking a viewpoint as a center and R as a radius, and shifting the viewpoint for k times to obtain k saliency regions of the inquired image; extracting a visual word in each of the saliency regions of the inquired image, to constitute a visual phrase, and jointing k visual phrases to generate an image descriptor of the inquired image; obtaining an image descriptor for each image of an inquired image library; and calculating a similarity value between the inquired image and each image in the inquired image library depending on the image descriptors by utilizing a cosine similarity, to obtain an image similar to the inquired image from the inquired image library. Through the present invention, noise in expression of an image is reduced, so that the expression of the image in a computer may be more consistent with human understanding of the semantics of the image, presenting a better retrieving effect and a higher retrieving speed.
Beijing University of Technology | Date: 2015-09-04
A method and device of torque generation based on electromagnetic effect is provided. An electromagnetic torque whose direction is opposite to the motor driving direction is generated in a magnetic field when a motor-drive armature winding is adopted based on the electro-magnetic induction principle. Meanwhile, a reverse electromagnetic torque which is reverse to the armature winding with the same magnitude, is applied on a magnet set and is transmitted to an underactuated system so as to provide required torque for the underactuated system. Advantageously, the provided torque is in direct ratio to speed, difficulty in control is significantly reduced, two-stage electromagnetic variable speed can be achieved, the design of the system is simple and reliable with a concise and clear structure, and the device may be employed in a wide variety of applications.
Beijing University of Technology | Date: 2014-04-18
A sandwich structure for enhancement of photoluminescence (PL) from luminescent films and the corresponding preparation method are disclosed. The sandwich structure comprises a support, a luminescent film grown on the support, and a close-packed dielectric microsphere monolayer deposited onto the luminescent film. The microspheres have high transmittance excitation light and emitted light, respectively. The low price of dielectric microspheres is beneficial to industrial applications. The stable chemical properties of dielectric microspheres make PL enhanced in a long term. Both metal and non-metal materials can be used as the support in the sandwich structure. These features significantly improve the technique of PL enhancement for luminescent films.