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991.
Photovoltaics: Investigation of Gold Quantum Dot Enhanced Organic Thin Film Solar Cells (Part. Part. Syst. Charact. 11/2017) 下载免费PDF全文
992.
Tatsuki Tahara Yasuhiro Awatsuji Atsushi Kaneko Takamasa Koyama Kenzo Nishio Shogo Ura Toshihiro Kubota Osamu Matoba 《Optical Review》2010,17(3):108-113
We propose an optical implementation of a parallel two-step phase-shifting digital holography that utilizes a polarization
technique. The implementation uses a phase-shifting array device consisting of a retarder array attached to an image sensor,
and does not require the optical system to image the phase-shifting array device onto the image sensor required for the previously
reported optical implementation of the parallel two-step phase-shifting digital holography. Then, the proposed implementation
is essentially simple to align and compose. A preliminary experiment showed that the parallel two-step phase-shifting digital
holography based on the proposed implementation can remove the conjugate image clinging to the image reconstructed by Fresnel
transform alone with DC term suppression. Also, when the reconstruction distance was changed, the qualities of the reconstructed
images were quantitatively evaluated by using normalized root-mean-square error. It was clarified that the proposed implementation
was superior to other parallel phase-shifting digital holographies and Fresnel transform alone. Thus, the validity of the
proposed implementation was confirmed. 相似文献
993.
Tatsuki Tahara Yasuhiro Awatsuji Kenzo Nishio Shogo Ura Toshihiro Kubota Osamu Matoba 《Optical Review》2010,17(6):519-524
We comparatively analyzed and quantitatively evaluated the field of view and the viewing zone of single-shot phaseshifting
digital holography that uses space-division multiplexing, for the first time. We formulated the sampling intervals in the
techniques in which the phase of the reference wave is spatially divided into two and four steps, and numerically simulated
the areas. It was clarified that each area of the spatial two-step phase-shifting technique was twice as wide as that of the
spatial four-step phase-shifting technique. We also experimentally investigated the areas. The ghost appeared for the spatial
four-step technique when the object was between the boundary of the field of view of the spatial two-step technique and that
of the spatial four-step technique, but did not appear for the spatial two-step technique. 相似文献
994.
Masafumi Baba Takehiko Fujishiro Shigeru Yamaguchi Kazuyoku Tei Makoto Yoshida Tsutomu Sakurai Ken-ichi Tanaka 《Optical Review》2010,17(2):50-53
We report progress in the design and fabrication of a monolithic, linearly polarized, pulsed, Yb-doped fiber laser. This laser
has a peak power of more than 100 kW, a tunable repetition rate from 100 kHz to 1 MHz, a tunable pulse duration from 2 ns
to 2.5 μs, and a diffraction-limited, linearly polarized output beam with a mean power of 21 W and a wavelength of 1064 nm.
A seed source that consists of a microchip Nd:YVO4 laser and an electro optic deflector is developed. Using this source, the repetition rate and pulse duration are varied independently
of each other. In addition, an excellent pulse-to-pulse repeatability is achieved. 相似文献
995.
Lanthanide metal complexes display luminescence with narrow bandwidth. Here, we present coupling of the luminescence from europium ion (Eu3+) with whispering gallery modes (WGMs) in conjugated polymer microsphere resonators. Self‐assembly of fluorene–terpyridine alternating copolymer, coordinated by Eu3+ (F8tpy‐Eu3+), forms well‐defined microspheres with an average diameter of 3.2 μm. Upon focused laser excitation, a microsphere of F8tpy copolymer displays WGM photoluminescence (PL) at a wide spectral range from 420 to 680 nm. In contrast, F8tpy‐Eu3+ hybrid microspheres exhibit sharp WGM PL at a narrow spectral range of 615–630 nm, which is characteristic of luminescence from Eu3+. The PL behavior indicates that photoinduced energy transfer from F8tpy to Eu3+ occurs efficiently. Furthermore, the intensity of the PL peak increases nonlinearly upon strong pumping, indicating that a lasing action appears with the threshold of 1.85 mJ cm?2. These results will pave the way for developing microlasers and photonic devices from soft organic materials. 相似文献
996.
Yuhao Huang Yunlong Gao Weigang He Zihao Wang Wei Li Aijun Lin Jinyi Xu Genzoh Tanabe Osamu Muraoka Xiaoming Wu Weijia Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(19):6466-6470
An efficient and divergent approach toward the synthesis of all four de‐O‐sulfonated sulfonium type α‐glucosidase inhibitors, originally isolated from plants of genus Salacia, is reported for the first time. The key strategy features a coupling reaction between thiol derivatives and a diiodide counterpart. The newly designed thiol coupling partner presents high chemical stability, while the diiodide partner could be easily obtained with increased overall yields compared with conventional routes. The intermolecular nucleophilic substitution reaction followed by a diastereoselective intramolecular cyclization provided the target five‐member sulfonium salt structure, which was connected in an α‐orientation to a polyhydroxylated side‐chain moiety. 相似文献
997.
Noriaki Miura Yuuki Noto Shuusuke Kato Fumihito Yokoyama Susumu Kuwamura Naoshi Baba Yoichiro Hanaoka Shin’ichi Nagata Satoru Ueno Reizaburou Kitai Kiyoshi Ichimoto Hideki Takami 《Optical Review》2009,16(5):558-561
A solar adaptive optics system has been improved by using a high-speed electromagnetic deformable mirror and adopting a modified sum-of-absolute-differences algorithm in wavefront sensing. Results of laboratory experiments clearly show that the use of the mirror raises the temporal performance of the system. In solar observations, wavefront compensation using solar granules as a target is realized. 相似文献
998.
Yasuko Yoshida Kentaro Iwai Kentaro Nagata Takehiko Seo Masato Mikami Osamu Moriue Tetsuya Sakashita Masao Kikuchi Takuma Suzuki Masaki Nokura 《Proceedings of the Combustion Institute》2019,37(3):3409-3416
This research conducted microgravity experiments on the flame spread over droplet-cloud elements with strong droplet interaction aboard Kibo on the ISS. The droplet-cloud element represents a local droplet pattern appearing in randomly distributed droplet clouds near the group-combustion-excitation limit and consists of small-droplet-spacing droplets and large-droplet-spacing droplets. As droplet-cloud elements, we used four n-decane droplets, Droplets C, B, A and L, placed at fiber intersections of two-dimensional SiC-fiber lattice with a 4-mm fiber interval in a combustion chamber. The flame spreads over the droplet-cloud element in order of Droplets C, B, A and L. The position of Droplet L relative to Droplet A was varied to investigate the flame-spread-limit distribution around burning Droplet A. The position of Droplet B relative to Droplet A was varied to investigate the effect of two-droplet interaction between Droplets B and A on the flame spread to Droplet L. The position of Droplet C relative to Droplet B was also varied to investigate the effect of three-droplet interaction among Droplets C, B and A. The results shows that in the case with the strong interaction by two or three interactive droplets, the high-temperature region is enlarged by the droplet interaction, centers near the center of mass of the interactive droplets and plays an important role in the flame-spread-limit distribution. Since the burning lifetime of Droplet A is finite, the flame-spread time from burning Droplet A to Droplet L is limited by burning lifetime of Droplet A and is less than 80% of the burning lifetime of Droplet A, which increases with the interactive effect. The flame-spread-limit distance from the center of mass of the interactive droplets increases with the burning lifetime. 相似文献
999.
Ekenechukwu C. Okafor K.D. Kunkuma A. Somarathne Akihiro Hayakawa Taku Kudo Osamu Kurata Norihiko Iki Hideaki Kobayashi 《Proceedings of the Combustion Institute》2019,37(4):4597-4606
Recent studies have demonstrated stable generation of power from pure ammonia combustion in a micro gas turbine (MGT) with a high combustion efficiency, thus overcoming some of the challenges that discouraged such applications of ammonia in the past. However, achievement of low NOx emission from ammonia combustors remains an important challenge. In this study, combustion techniques and combustor design for efficient combustion and low NOx emission from an ammonia MGT swirl combustor are proposed. The effects of fuel injection angle, combustor inlet temperature, equivalence ratio, and ambient pressure on flame stabilization and emissions were investigated in a laboratory high pressure combustion chamber. An FTIR gas analyser was employed in analysing the exhaust gases. Numerical modeling using OpenFOAM was done to better understand the dependence of NO emissions on the equivalence ratio. The result show that inclined fuel injection as opposed to vertical injection along the combustor central axis resulted to improved flame stability, and lower NH3 and NOx emissions. Numerical and experimental results showed that a control of the equivalence ratio upstream of the combustor is critical for low NOx emission in a rich-lean ammonia combustor. NO emission had a minimum value at an upstream equivalence ratio of 1.10 in the experiments. Furthermore, NO emission was found to decrease with ambient pressure, especially for premixed combustion. For the rich-lean combustion strategy employed in this study, lower NOx emission was recorded in premixed combustion than in non-premixed combustion indicating the importance of mixture uniformity for low NOx emission from ammonia combustion. A prototype liner developed to enhance the control and uniformity of the equivalence ratio upstream of the combustor further improved ammonia combustion. With the proposed liner design, NOx emission of 42?ppmv and ammonia combustion efficiency of 99.5% were achieved at 0.3?MPa for fuel input power of 31.44?kW. 相似文献
1000.
Baba T Yokoya T Tsuda S Kiss T Shimojima T Ishizaka K Takeya H Hirata K Watanabe T Nohara M Takagi H Nakai N Machida K Togashi T Watanabe S Wang XY Chen CT Shin S 《Physical review letters》2008,100(1):017003
We have performed temperature- (T-)dependent laser-photoemission spectroscopy of the antiferromagnetic (AF) superconductor ErNi2B2C to study the electronic-structure evolution reflecting the interplay between antiferromagnetism and superconductivity. The spectra at the superconducting (SC) phase show a very broad spectral shape. A T-dependent SC gap shows a sudden deviation from the BCS prediction just below TN. This observation can be explained well by the theoretical model and thus represents the characteristic bulk electronic structure of the AF SC phase for the first time. 相似文献