http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Ayumi Nakajima (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Response of Resin Coating Films Containing Fine Metal Particles to Ultrashort Laser Pulses
Ayumi Nakajima,Jiwang Yan 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.4
Resin coating films are extensively used for aesthetic improvement and preventing deterioration of metal surfaces. Some of the films contain fi ne metal particles for the purpose of coloring. For such films, surface waviness with millimeter-scale wavelength is a significant problem because it induces visible irregularities on the surface. Conventionally, man-powered polishing has been used to planarize the waviness. However, it is labor-intensive and leads to other problems such as waste slurry disposal and embedment of abrasive grains in the fi lm. Hence, a new method is required to eliminate the surface waviness. In this study, ultrashort pulsed laser irradiation on resin coating films is proposed. By controlling the focal position and/or scanning speed of the laser beam along the surface, protrusions are preferentially removed. Firstly, the effects of pulse width, laser fluence, and scanning speed on surface morphology were clarified. Next, the material removal mechanism was examined by elemental analysis of the surface and its cross section after irradiation. Finally, as a preliminary result of surface flattening, the arithmetic mean waviness in the wavelength range of 2.4–5.0 mm was reduced by 45.3%. This study demonstrated the feasibility of selectively removing and flattening of resin coating films by substituting laser processing for man-powered polishing.
-
Charge Density Study of Negative-Thermal-Expansion Material ZrW2O8
Ayumi Kojima,Yoshihiro Kuroiwa,Akikatsu Sawada,Noriyuki Nakajima,Shinobu Aoyagi,Toshihide Tsuji,Yasuhisa Yamamura 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV
The covalent bonding nature of the negative thermal expansion material, ZrW2O8, has been revealed in the accurate charge-density distribution at 300 K, by analyzing the synchrotron-radiation high-energy powder-diraction data by the MEM/Rietveld method. It is found that two WO4 tetrahedra are bonded covalently by the bridging O atom along the body diagonal directions in the cubic structure. The bonding electron density between the W atom and the terminal O atom, which has a key to the mechanism of the order-disorder phase transition, is highest among the W-O covalent bonds.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
