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1.
2.
Jem‐Kun Chen I‐Kuan Lin Fu‐Hsiang Ko Chih‐Feng Huang Kuo‐Shen Chen Chia‐Hao Chan Feng‐Chih Chang 《Journal of Polymer Science.Polymer Physics》2004,42(22):4063-4074
Polybenzoxazine (PBZZ) thin films can be fabricated by the plasma‐polymerization technique with, as the energy source, plasmas of argon, oxygen, or hydrogen atoms and ions. When benzoxazine (BZZ) films are polymerized through the use of high‐energy argon atoms, electronegative oxygen atoms, or excited hydrogen atoms, the PBZZ films that form possess different properties and morphologies in their surfaces. High‐energy argon atoms provide a thermodynamic factor to initiate the ring‐opening polymerization of BZZ and result in the polymer surface having a grid‐like structure. The ring‐opening polymerization of the BZZ film that is initiated by cationic species such as oxygen atoms in plasma, is propagated around nodule structures to form the PBZZ. The excited hydrogen atom plasma initiates both polymerization and decomposition reactions simultaneously in the BZZ film and results in the formation of a porous structure on the PBZZ surface. We evaluated the surface energies of the PBZZ films polymerized by the action of these three plasmas by measuring the contact angles of diiodomethane and water droplets. The surface roughness of the films range from 0.5 to 26 nm, depending on the type of carrier gas and the plasma‐polymerization time. By estimating changes in thickness, we found that the PBZZ film synthesized by the oxygen plasma‐polymerization process undergoes the slowest rate of etching in CF4 plasma. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4063–4074, 2004 相似文献
3.
We study condensation of ethanol-hexanol vapour by numerical solution of kinetic equations. The number of droplets formed
in unit volume is computed within self-consistent classical model. It is shown that formation of ethanol-rich droplets prevails
at the initial stage of nucleation process, but in the stationary state formation of droplets near the saddle point (on cluster
formation energy surface) plays the dominant role.
Presented at the 6th Joint Seminar “Development of Materials Science in Research and Education”, Karlštejn, Czech Republic,
17–19 September 1996.
This work was supported by Grant No. A1010615 of the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
4.
Piotr Ko?cielniak 《Topology and its Applications》2007,154(9):1951-1955
Let M be a compact manifold with dimM?2. We prove that some iteration of the generic homeomorphism on M is semiconjugated to the shift map and has infinite topological entropy (Theorem 1.1). 相似文献
5.
A closed microwave digestion method followed by inductively coupled plasma spectrometric (ICP-MS) analysis was evaluated for the determination of trace impurities in photoresist. To optimize the digestion procedure, several digestion parameters such as acid, heating temperature and heating time were evaluated. Besides, the digestion efficiency of used photoresist material and the recovery of analyte elements obtained by the use of gravimetric method and ICP-MS measurement, individually, were also compared to clarify the completeness of digestion. According to our experiments, the gravimetric method was found to be not so relevant to the completeness of digestion, because the remaining sample matrix could cause suppression effect in the subsequent ICP-MS measurement. In view of minimizing blank value and working time, a simple single-step heating program was proposed to mineralize 0.25 ml of photoresist material with 5 ml of nitric acid at 180 °C for 10 min. Based on the comparative study of the analytical results obtained by instrumental neutron activation analysis (INAA) and proposed method, the reliability of proposed method for the determination of trace metallic impurities in photoresist material has been confirmed. 相似文献
6.
Formation of p-type ZnO film on InP substrate by phosphor doping 总被引:3,自引:0,他引:3
Kyu-Hyun Bang Deuk-Kyu Hwang Min-Chul Park Young-Don Ko Ilgu Yun Jae-Min Myoung 《Applied Surface Science》2003,210(3-4):177-182
ZnO thin film was initially deposited on InP substrate by radio frequency (rf) magnetron sputtering and the diffusion process was performed using the closed ampoule technique where Zn3P2 was used as the dopant source. To verify the junction formation of ZnO thin films, the electrical properties were measured, and the effects of Zn3P2 diffusion on ZnO thin films were investigated. It is observed that the electrical property of the film is changed from n-type to p-type by dopant diffusion effect. Based on the results, it is confirmed that ZnO thin films can be a potential candidate for ultraviolet (UV) optical devices. 相似文献
7.
For the methylsilsesquioxane film whose optical birefringence is almost zero, it was recently reported that its vertical thermal expansion coefficient (CTE) was approximately one order of magnitude larger than the lateral CTE. Though the birefringence is not an absolute predictor of anisotropic behavior, the discrepancy in both the CTEs was so remarkable that it was essential to investigate whether the anisotropy was intrinsic property or not. If the effect of Poisson's ratio is considered in the calculation of the vertical CTE and when elastic modulus measured by surface acoustic wave spectroscopy is used in the assessment of the lateral CTE, both the CTEs are coincident with each other. Therefore, it can be concluded that the discrepancy in the CTEs can be attributed to a higher in‐plane polymer chain orientation but it can also arise from the misleadingly assumed modulus and Poisson's ratio. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3109–3120, 2006 相似文献
8.
9.
Ha Yong Lee Se Hun Jung Soo Yong Lee Young Ho You Kyung Hyun Ko 《Applied Surface Science》2005,252(5):1891-1898
Al-Al2O3 composite coatings with different Al2O3 particle shapes were prepared on Si and Al substrate by cold spray. The powder compositions of metal (Al) and ceramic (Al2O3) having different sizes and agglomerations were varied into ratios of 10:1 wt% and 1:1 wt%. Al2O3 particles were successfully incorporated into the soft metal matrix of Al. It was found that crater formation between the coatings and substrate, which is typical characteristic signature of cold spray could be affected by initial starting Al2O3 particles. In addition, when the large hard particles of fused Al2O3 were employed, the deep and big craters were generated at the interface between coatings and hard substrates. In the case of pure soft metal coating such as Al on hard substrate, it is very hard to get proper adhesion due to lack of crater formation. Therefore, the composite coating would have certain advantages. 相似文献
10.
The present paper summarizes detailed investigations of Nd3+ fluorescence spectra in YAP:Nd laser crystal in the broad spectral range of 370–1100 nm at liquid nitrogen temperature. Especially, Nd3+ near UV and visible fluorescence spectra were studied for the first time in this crystal. The Nd3+ near UV and visible fluorescence spectra of this crystal consist of many narrow lines (up to 50). The Nd3+ near UV and visible fluorescence lines arise mainly from4D3/2 and2P3/2 Nd3+ terms (transitions from4D3/2,2P3/2 to lower lying Nd3+ levels are responsible for their appearance). At room temperature the fluorescence spectra consist of broad bands with narrow lines (mainly4D3/24F3/2,4F5/2 and2H9/2 transitions). 相似文献