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31.
Femtosecond lasers have opened up new avenues in materials processing due to their unique characteristics of ultrashort pulse widths and extremely high peak intensities. One of the most important features of femtosecond laser processing is that a femtosecond laser beam can induce strong absorption in even transparent materials due to nonlinear multiphoton absorption. This makes it possible to directly create three-dimensional (3D) microfluidic structures in glass that are of great use for fabrication of biochips. For fabrication of the 3D microfluidic structures, two technical approaches are being attempted. One of them employs femtosecond laser-induced internal modification of glass followed by wet chemical etching using an acid solution (Femtosecond laser-assisted wet chemical etching), while the other one performs femtosecond laser 3D ablation of the glass in distilled water (liquid-assisted femtosecond laser drilling). This paper provides a review on these two techniques for fabrication of 3D micro and nanofluidic structures in glass based on our development and experimental results. 相似文献
32.
We express a basis for the vector space of finite type invariants of order less than or equal to three for an embedded handcuff graph in a 3-sphere in terms of the linking number, the Conway polynomial, and the Jones polynomial of the sublinks of the handcuff graph. 相似文献
33.
Tsuzuki S Wakisaka A Ono T Sonoda T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(3):951-960
The geometries and interaction energies of complexes of pyridine with C6F5X, C6H5X (X=I, Br, Cl, F and H) and RFI (RF=CF3, C2F5 and C3F7) have been studied by ab initio molecular orbital calculations. The CCSD(T) interaction energies (Eint) for the C6F5X–pyridine (X=I, Br, Cl, F and H) complexes at the basis set limit were estimated to be ?5.59, ?4.06, ?2.78, ?0.19 and ?4.37 kcal mol?1, respectively, whereas the Eint values for the C6H5X–pyridine (X=I, Br, Cl and H) complexes were estimated to be ?3.27, ?2.17, ?1.23 and ?1.78 kcal mol?1, respectively. Electrostatic interactions are the cause of the halogen dependence of the interaction energies and the enhancement of the attraction by the fluorine atoms in C6F5X. The values of Eint estimated for the RFI–pyridine (RF=CF3, C2F5 and C3F7) complexes (?5.14, ?5.38 and ?5.44 kcal mol?1, respectively) are close to that for the C6F5I–pyridine complex. Electrostatic interactions are the major source of the attraction in the strong halogen bond although induction and dispersion interactions also contribute to the attraction. Short‐range (charge‐transfer) interactions do not contribute significantly to the attraction. The magnitude of the directionality of the halogen bond correlates with the magnitude of the attraction. Electrostatic interactions are mainly responsible for the directionality of the halogen bond. The directionality of halogen bonds involving iodine and bromine is high, whereas that of chlorine is low and that of fluorine is negligible. The directionality of the halogen bonds in the C6F5I– and C2F5I–pyridine complexes is higher than that in the hydrogen bonds in the water dimer and water–formaldehyde complex. The calculations suggest that the C? I and C? Br halogen bonds play an important role in controlling the structures of molecular assemblies, that the C? Cl bonds play a less important role and that C? F bonds have a negligible impact. 相似文献
34.
A persistent perfluoroalkyl radical (PPFR), perfluoro‐3‐ethyl‐2,4‐dimethyl‐3‐pentyl, is shown to be a good source of •CF3 radicals and a useful radical capable of initiating the polymerization of vinylidene fluoride (VDF). NMR characterizations of the resulting PVDF homopolymers showed that polymerization of VDF was exclusively initiated by •CF3 radicals. The addition of •CF3 radical onto VDF was regioselective leading to CF3‐CH2‐CF2‐PVDF and the CF3 end‐group acted as an efficient label to assess the molecular weights by 19F NMR spectroscopy. Various [PPFR]0/[VDF]0 initial molar ratios lead to CF3–PVDF–CF3 of different molecular weights. When that ratio decreased, both the molecular weights and the thermostability of these PVDFs increased, showing less defects of chaining and higher crystallinity. 相似文献
35.
K. Obata K. Sugioka T. Akane N. Aoki K. Toyoda K. Midorikawa 《Applied Physics A: Materials Science & Processing》2001,73(6):755-759
A collinear irradiation system of F2 and KrF excimer lasers for high-quality and high-efficiency ablation of hard materials by the F2 and KrF excimer lasers’ multi-wavelength excitation process has been developed. This system achieves well-defined micropatterning
of fused silica with little thermal influence and little debris deposition. In addition, the dependence of ablation rate on
various conditions such as laser fluence, irradiation timing of each laser beam, and pulse number is examined to investigate
the role of the F2 laser in this process. The multi-wavelength excitation effect is strongly affected by the irradiation timing, and an extremely
high ablation rate of over 30 nm/pulse is obtained between -10 ns and 10 ns of the delay time of F2 laser irradiation. The KrF excimer laser ablation threshold decreases and its effective absorption coefficient increases
with increasing F2 laser fluence. Moreover, the ablation rate shows a linear increase with the logarithm of KrF excimer laser fluence when the
F2 laser is simultaneously irradiated, while single KrF excimer laser ablation shows a nonlinear increase. The ablation mechanism
is discussed based on these results.
Received: 16 July 2001 / Accepted: 27 July 2001 / Published online: 2 October 2001 相似文献
36.
Takuo Sugioka Allan S. Hay 《Journal of polymer science. Part A, Polymer chemistry》2001,39(8):1149-1155
Novel fully lower‐rim, carbonate‐bridged calix[8]arene derivatives were successfully synthesized in high yield by the condensation of p‐alkyl substituted calix[8]arenes with triphosgene. Different bases and catalysts were used for the preparation depending on the p‐alkyl substituted groups of the calix[8]arenes. The conformational features of the derivatives were examined by 1H NMR analysis. Thermosetting formulations were prepared from a mixture of bisphenol A polycarbonate with calix[8]arene carbonate derivatives using sodium benzoate as a catalyst. Their crosslinking behaviors were studied using differential thermal/thermogravimetric analysis. No glass‐transition temperatures were observed after annealing at 280–300 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1149–1155, 2001 相似文献
37.
Satoshi Takeuchi Saburo Endo Taizo Irie 《Journal of Physics and Chemistry of Solids》1985,46(8):887-893
Near infrared absorption spectra of n-type CuIn5S8 single crystals were measured. Two structures were found in the spectra in the photon energy range from ?ω ? 0.3 eV?1.2 eV. One of them is the free carrier absorption below 0.6 eV in which the absorption coefficient increases as the third power of the wavelength. It was found that this absorption was associated with the multiple scattering mechanisms. Another structure seems, from its temperature and carrier-concentration dependences, to be associated with an absorption due to a transition from a lower lying conduction band to an upper one. 相似文献
38.
Examples on polynomial invariants of knots and links 总被引:1,自引:0,他引:1
Taizo Kanenobu 《Mathematische Annalen》1986,275(4):555-572
39.
High-speed machining of glass materials by laser-induced plasma-assisted ablation using a 532-nm laser 总被引:2,自引:0,他引:2
J. Zhang K. Sugioka K. Midorikawa 《Applied Physics A: Materials Science & Processing》1998,67(4):499-501
+ :YAG laser (532 nm). The plasma generated from a silver (Ag) target by the laser irradiation effectively assists in ablation
of the fused quartz substrate by the same laser beam, although the laser beam is transparent to the substrate. A grating with
a cross-sectional shape like a square-wave (period ≈ 20 μm) is achieved using the mask projection technique. The ablation
rate reaches several tens nm/pulse. In addition, LIPAA is applied to high-speed hole drilling (700 μm in diameter) of fused-quartz
(0.5 mm thick) and Pyrex glass (0.5 mm thick).
Received: 25 May 1998/Accepted: 19 June 1998 相似文献
40.
Shoji Kitamura Saburo Endo Taizo Irie 《Journal of Physics and Chemistry of Solids》1985,46(8):881-885
The electrical resistivity and Hall coefficient of n-type CuIn5S8 single crystals were measured in the temperature range from 80 K–500 K. The energy gap at 0 K was determined to be 1.4 eV. The donor levels at 0.017 eV and 0.09 eV below the conduction band are identified. The mobility data are analysed assuming scatterings by acoustic and polar optical phonons and ionized impurities. 相似文献