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 : Zhenghua Meng (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
-
Jinfeng Gong,Fanming Meng,Zhenghua Fan,Huijie Li 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.6
Monodisperse 3D lotus-like CeO2 microstructures have beensuccessfully synthesized via controlling the morphology ofCeCO3OH precursors under hydrothermal condition as wellas subsequent calcination. The reaction time wassystematically investigated. XRD, FT-IR, SEM, TEM, XPS,Raman scattering and Photoluminescence (PL) spectra wereemployed to characterize the samples. The lotus-like CeO2hierarchical structures with an average of 4-6 μm arecomposed of many nanoplates of 100-200 nm in thickness asthe petals stacking together to form open flowers and have a fluorite cubic structure. Based on the time-dependent morphologyevolution evidences, a nucleation-dissolution-recrystallization mechanism has been proposed to explain the transformation fromrod-like structures to lotus-like CeO2 hierarchical structures with the increase of reaction time. It is found that there are Ce3+ ionsand oxygen vacancies in surface of samples. The magnetic and photoluminescence measurements indicated that all CeO2samples exhibit excellent ferromagnetism and optical properties at room temperature, and while increasing the reaction time, theferromagnetism and optical properties increase more, which can be reasonably explained for the influences of the differentmorphology of the particles and the concentration of oxygen vacancies and Ce3+ ions.
-
Huijie Li,Fanming Meng,Jinfeng Gong,Zhenghua Fan,Rui Qin 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.4
CeO2 nanospheres with the core–shell nanostructure have been successfully synthesized by a template-free hydrothermalmethod. The structures, morphologies and optical properties of core–shell CeO2nanospheres were analyzed by X-ray diffraction(XRD), TG, Fourier transform infrared spectroscopy, XRD, EDS, SAED, scanning electron microscopy and transmissionelectron microscopy, UV–Vis diffuse reflectance spectra, Raman analyses. The degradation efficiencies of core–shell CeO2nanospheres for methyl orange were as high as 93.49, 95.67 and 98.28% within 160 min, and the rates of photo degradationof methyl orange by core–shell CeO2nanospheres under UV-light were 0.01693, 0.01782 and 0.02375 min−1. Methyl orangewas degraded in photocatalytic oxidation processes, which mainly gave the credit to a large number of reactive species includingh+,surface superoxide species ·O2−, and ·OH radicals. The core–shell structure, small crystallite size and the conversionbetween Ce3+and Ce4+of CeO2nanospheres were of importance for its catalytic activity. These results demonstrated thepossibility of improving the efficient catalysts of the earth abundant CeO2catalysts.
-
Prediction of warpage in plastic injection molding based on design of experiments
Wei Guo,Lin Hua,Huajie Mao,Zhenghua Meng 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.4
In terms of injection processing parameters, a mathematical model for prediction of warpage was formulated based on design of experiments (DOE). First, the five most influential parameters were screened by using fractional factorial design (FFD): melt temperature,coolant temperature, injection time, V/P switch over and mold temperature. Second, considering the other four principal processing parameters except the melt temperature, the predicting mathematical model was founded by using central composite design (CCD) of experiments and FE simulation. Finally, the results of statistical analysis were collected from software Moldflow. The results suggested that the mathematical model can be used to predict warpage with adequate accuracy. Hence, it indicated that corrective and iterative design steps can be initiated and implemented for better quality of products without resorting to physical trials in plastics injection mold by using this predicting mathematical model.
-
Wei Guo,Bo He,Huajie Mao,Mengying Zhang,Lin Hua,Zhenghua Meng 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7
A combined in-mold decoration and microcellular foaming injection molding process (IMD/Mucell) is proposedto improve the surface quality of foamed parts. Through theoretical inference, the mathematical models of temperature field,velocity profile and forces on bubble were established with combining traditional mathematical models and the different heattransfer coefficient of the mold inner surface. The effects of the non-isothermal mold on the bubble structure and formingprocess of inter bubble were investigated with experiments and numerical simulation. Results showed that the criticalpressure of the cavity existed in the melt filling and bubble expanding stage, and it affected the cells structure obviously at thefilling stage. The lift force took the bubbles to the film side based on the velocity profile of viscous fluid, and maximal bubblewas closer to the transition layer with film due to higher temperature. In the combined process, the evolution rule ofsuperficial bubbles was analyzed, and results showed that the surface quality was improved in the film side.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
