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291.
Jun‐ichi Ikeda Yasuhide Hasei Yuduri Yasuda Hiroyuki Aota Akira Matsumoto 《应用聚合物科学杂志》2004,94(3):1086-1093
d‐Bornyl methacrylate (BoMA) was chosen as a typical example of bulky monomethacrylate monomers, the polymerization of which led to the formation of a rigid polymer chain. To discuss the effect of primary polymer chain rigidity on intramolecular cyclization, we compared the solution copolymerization results of BoMA with 1 mol % ethylene dimethacrylate (EDMA; n = 1) and poly(ethylene glycol dimethacrylate) [CH2?C(CH3)CO(OCH2CH2)nOCOC(CH3)?CH2, n = 9 (PEGDMA‐9)] with those of methyl methacrylate (MMA) with 1 mol % EDMA and PEGDMA‐9; the dependence of the weight‐average degree of polymerization on conversion for the former BoMA copolymerization systems was completely opposed to that for the latter MMA systems, and this was a reflection of a reduced occurrence of intramolecular cyclization caused by the rigidity of the primary polymer chain. The effect of primary polymer chain rigidity on intramolecular crosslinking was discussed through a comparison of both BoMA/EDMA and MMA/EDMA copolymerizations. The correlations of the intrinsic viscosity, root‐mean‐square (rms) radius of gyration, and second virial coefficient with the molecular weight were examined for both BoMA/EDMA (90/10) and MMA/EDMA (90/10) copolymerizations in a dilute solution because microgelation was observed in solution MMA/EDMA (90/10) copolymerization as a reflection of a locally extensive occurrence of intramolecular crosslinking. The logarithmic plots of both the intrinsic viscosity and rms radius of gyration versus the molecular weight for MMA/EDMA copolymerization were compared with those for the corresponding BoMA/EDMA copolymerizations. The second virial coefficients were greater than 10?5 mol cm3 g?2 for BoMA/EDMA copolymers, even when the conversion was very close to the gel point, whereas they were quite low, that is, less than 10?5 mol cm3 g?2, for an MMA/EDMA copolymer obtained at more than 15% conversion. These were ascribed to a suppressed occurrence of intramolecular crosslinking, a reflection of the lessened flexibility of the polymer main chain and a steric effect due to the bulky d‐bornyl groups. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1086–1093, 2004 相似文献
292.
Mizuki Ono Tsunehiro Ino Masato Koyama Akira Takashima Akira Nishiyama 《Solid-state electronics》2004,48(12):2191-2198
It is shown that propagation delay time in CMIS (complementary metal insulator semiconductor field effect transistor) inverters is strongly affected by dielectric constant nonuniformity in gate dielectrics caused by the phase separation in silicate films. Influences of such nonuniformity on load capacitance are studied by analytical calculations based on a physical model which takes polarization into account. It is newly found that load capacitances are affected by the phase separation in qualitatively different ways, depending on the average metal concentration of their dielectric films. An experimental result is compared with those calculations. Influences of such nonuniformity on current drivability are studied by 3-dimensional device simulations. It is also newly found that such nonuniformity affects load capacitance and current drivability in different ways, resulting in an increase in propagation delay time of CMIS inverters for all metal concentrations studied. An explanation of this phenomenon is given with physical considerations. 相似文献
293.
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295.
Low-Friction Coatings of Zinc Oxide Synthesized by Optimization of Crystal Preferred Orientation 总被引:1,自引:0,他引:1
The crystal preferred orientation of zinc oxide (ZnO) coatings on stainless steel substrates was precisely controlled by a
combinatorial sputter-coating system. ZnO coatings were analyzed by X-ray diffraction spectroscopy, and surface and interfacial
cutting analysis methods. The frictional properties of the coatings in a vacuum, the atmosphere, oil of n-hexadecane, and oil doped with palmitic acid molecules were observed. Different frictional behaviors of the ZnO coatings
were observed by varying the crystal preferred orientation. A low-friction coefficient as less as 0.2 was realized by ZnO
coatings with uni- and multi-crystal orientation in all of those conditions. Inverse proportion of the friction coefficient
to normal load was observed on ZnO coatings with bi-orientation of (002) and (103) in pure and palmitic acid doped oil. 相似文献
296.
Kaneko S Ito T Akiyama K Yasui M Kato C Tanaka S Hirabayashi Y Mastuno A Nire T Funakubo H Yoshimoto M 《Nanotechnology》2011,22(17):175307
After a laser annealing experiment on Si wafer, we found an asymmetric sheet resistance on the surface of the wafer. Periodic nano-strip grating lines (nano-SGLs) were self-organized along the trace of one-time scanning of the continuous wave (CW) laser. Depending on laser power, the nano-trench formed with a period ranging from 500 to 800 nm with a flat trough between trench structures. This simple method of combining the scanning laser with high scanning speed of 300 m min(-1) promises a large area of nanostructure fabrication with a high output. As a demonstration of the versatile method, concentric circles were drawn on silicon substrate rotated by a personal computer (PC) cooling fan. Even with such a simple system, the nano-SGL showed iridescence from the concentric circles. 相似文献
297.
Toshiyuki Yamaguchi Toshitsugu Kobata Shigetoshi Niiyama Takashi Nakamura Akira Yoshida 《Solar Energy Materials & Solar Cells》2003,75(1-2):87-92
Thin films of Cu–In–Ga–Se alloy system with various composition were prepared by thermal crystallization from In/CuInGaSe/In precursor. Electron probe microanalysis and X-ray diffraction study revealed that these samples were assigned to chalcopyrite Cu(In,Ga)Se2 or ordered vacancy compound Cu(In,Ga)2Se3.5. Solar cell with ZnO:Al/i–ZnO/CdS/Cu(In,Ga)Se2/Mo/soda-lime glass substrate structure was fabricated by using thermal crystallization technique, and demonstrated a 9.58% efficiency without AR-coating. 相似文献
298.
Ghosts and flares are well-known problems that are caused by reflections from lens surfaces when we take photographs. It is more difficult to prevent such stray light in a digital camera than in a film camera because of high reflectance from the low-pass filter and diffraction from the image sensor. To prevent such stray light, we introduce an ultralow refractive index layer into the antireflective (AR) coatings. We used the solgel method to form porous fluoride layers with ultralow refractive indices, and we succeeded in developing a unique process to form AR coatings with superior performance. 相似文献
299.
Ken-ichi?KatsumataEmail author Takeshi?Wada Akihisa?Inoue Munetoshi?Sakai Akira?Nakajima Akira?Fujishima Nobuhiro?Matsushita Kiyoshi?Okada 《Journal of Materials Science》2011,46(10):3430-3435
The surfaces of the Ti-based bulk metallic glasses (Ti50Ni20Cu25Sn5) were modified by a hydrothermal method using sodium hydroxide (NaOH) solution, and the surface wettability was investigated.
No reflections were observed in the XRD patterns of the NaOH-treated samples even though there was a clear change of the color,
indicating formation of amorphous oxide phases. The Raman spectra showed peaks attributed to sodium titanate compounds (Na–O–Ti)
and titanium oxide. Some of the samples were observed to have a very rough surface microstructure such as a “house-of-cards”
or leaf-like structure. The water contact angle of the treated samples decreased with increasing treatment temperature and
time. These results indicate that the wettability of the sample surface was able to be controlled from hydrophobic to hydrophilic
by changing the conditions of the hydrothermal treatment. 相似文献
300.
Akira Miyazaki Takayuki Yamazaki Taikan Suehara Toshio Namba Shoji Asai Tomio Kobayashi Haruo Saito Toshitaka Idehara Isamu Ogawa Yoshinori Tatematsu 《Journal of Infrared, Millimeter and Terahertz Waves》2014,35(1):91-100
Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Pérot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months. 相似文献