每个女孩的梦想,大概都是遇到自己生命中的王子,而每个美妙故事的结局,莫过于王子和公主的结合。爱情里那些一幕幕动人的甜蜜窝心场景,王子和公主从相识、相恋到互相认定,最后挽手走向人生舞台的动人故事,是每个女孩生命中最值得珍视的...每个女孩的梦想,大概都是遇到自己生命中的王子,而每个美妙故事的结局,莫过于王子和公主的结合。爱情里那些一幕幕动人的甜蜜窝心场景,王子和公主从相识、相恋到互相认定,最后挽手走向人生舞台的动人故事,是每个女孩生命中最值得珍视的美好时光。璀璨的爱情故事背后,需要一个完美的铭记。代表永恒爱惰的钻石,是对我们美好爱情的最好祝福,是爱情路上完美的句点和婚姻生活的幸福开端。周生生独家的The Love Diamond<sup>TM</sup>,以"超完美车工"为每一颗钻石注入最光采动人的祝福。有了The Love Diamond<sup>TM</sup>的完美铭记,王子和公主的结合绽放出了世上最璀璨的幸福光芒。展开更多
The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can ob...The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can obtain low friction and good wear resistance with evolving surface morphology. By analyzing the mechanism of the surface of a dung beetle for reducing soil wear and adherence, we design a cemented carbide drill bit with a bionic surface, which is expected to have superior anti-wearing and anti-sticking properties for drilling the soft coal seam. Inspired from the characteristics of the head and pronotum surface of the dung beetle, optimized non-smooth surface of the drill bit was constructed. The working performance of this innovative drill was experimentally tested. With comparative experiments under the identical drilling conditions, the wear rates, drilling times of conventional drills and bionic drills were measured. Compared with the conventional counterpart, the drill designed exhibits better performance in reducing wear and sticking drilling-breaks, therefore achieving higher levels of efficiency. The diameter of the dome and pit on the bit surface is in the range of 0.8–1.2 mm, and the bionic drill bits could get better performance with preferable drilling speeds and wear rates.展开更多
文摘每个女孩的梦想,大概都是遇到自己生命中的王子,而每个美妙故事的结局,莫过于王子和公主的结合。爱情里那些一幕幕动人的甜蜜窝心场景,王子和公主从相识、相恋到互相认定,最后挽手走向人生舞台的动人故事,是每个女孩生命中最值得珍视的美好时光。璀璨的爱情故事背后,需要一个完美的铭记。代表永恒爱惰的钻石,是对我们美好爱情的最好祝福,是爱情路上完美的句点和婚姻生活的幸福开端。周生生独家的The Love Diamond<sup>TM</sup>,以"超完美车工"为每一颗钻石注入最光采动人的祝福。有了The Love Diamond<sup>TM</sup>的完美铭记,王子和公主的结合绽放出了世上最璀璨的幸福光芒。
基金supported by the National Natural Science Foundation of China(Grant Nos.51204122&51134018)the Natural Science Foundation of Jiangsu Province(Grant No.BK20140411)+3 种基金State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and AstronauticsMCMS-0414Y01)the National Basic Research Program of China(“973”Project)(Grant No.2014CB239203)the 111 Project(Grant No.B14006)
文摘The development of a high-performance cemented carbide drill bit is of great significance to the reduction of rock drilling-cost. The non-smooth features of a biological surface provide an insight into how they can obtain low friction and good wear resistance with evolving surface morphology. By analyzing the mechanism of the surface of a dung beetle for reducing soil wear and adherence, we design a cemented carbide drill bit with a bionic surface, which is expected to have superior anti-wearing and anti-sticking properties for drilling the soft coal seam. Inspired from the characteristics of the head and pronotum surface of the dung beetle, optimized non-smooth surface of the drill bit was constructed. The working performance of this innovative drill was experimentally tested. With comparative experiments under the identical drilling conditions, the wear rates, drilling times of conventional drills and bionic drills were measured. Compared with the conventional counterpart, the drill designed exhibits better performance in reducing wear and sticking drilling-breaks, therefore achieving higher levels of efficiency. The diameter of the dome and pit on the bit surface is in the range of 0.8–1.2 mm, and the bionic drill bits could get better performance with preferable drilling speeds and wear rates.
