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171.
172.
Yoshiaki Ueda Takanori Koga Hideaki Misawa Noriaki Suetake Eiji Uchino 《Optical Review》2017,24(3):406-415
In the present paper, we propose an image contrast enhancement method that can enhance the contrast of a color image naturally by taking account of a color space shape. The proposed method realizes the natural enhancement based on two kinds of intensity histograms: a gradient-norm-based histogram and an ideal histogram derived from the shape of a color space. The former histogram is used to suppress over-enhancement in the flat regions of an image and the latter histogram is used to prevent the whole image from being darken. Concretely, the aforementioned intensity histograms are appropriately mixed into a histogram with a weight based on the average intensity of the input image. The contrast enhancement of the input image is realized using the cumulative histogram of the mixed histogram as an intensity transform function. To verify the validity of the proposed method, in experiments, the proposed method is applied to a variety of images and experimental results are evaluated qualitatively and quantitatively. 相似文献
173.
Ultrasound intensity microscopy was developed for in vivo imaging. This paper describes the preliminary results obtained using 300 MHz ultrasound intensity microscopy for in vitro characterization of cell cultures. The novelty of the approach lies in the fact that it allows remote, non-contact and disturbance-free imaging of cultured synovial cells and the changes in the cells’ properties due to external stimulants such as transforming growth factor beta-1 (TGF-β1). The intensity imaging method has potential for extracting mechanical cell properties and monitoring the effects of drugs.Ultrasound propagates through a thin specimen such as cultured cells and is reflected at the interface between the specimen and substrate. A two-dimensional distribution of the ultrasonic intensity, which is closely related to the mechanical properties, is visualized to analyze cell organs, such as the nucleus at the central part and the cytoskeleton at the peripheral zone. After stimulation with TGF-β1, the ultrasonic intensity at the actin zone was significantly increased compared with the control. 相似文献
174.
Takeshi Miki Kaori Nishizawa Eiji Watanabe Hiroshi Taoda 《Research on Chemical Intermediates》2009,35(3):257-262
To obtain porous TiO2 film, the precursor sol was prepared by hydrolysis of Ti isopropoxide and then complexed with trehalose dihydrate. The porous
TiO2 film was fabricated by the dip-coating technique on glass substrates using this solution. The TiO2 film was calcined at 500 °C. The maximum thickness of the film from one-run dip-coating was ca. 740 nm. The film was composed
of nanosized particle and pores. The porosity of the TiO2 film was increased by addition of trehalose dihydrate to the sol. The porous TiO2 films were calcined at different temperatures. The effects of calcination temperature on the microstructure of the porous
TiO2 film were investigated. The porous film prepared from sol containing trehalose still kept the porous structure after calcination
at 950 °C. The phase transition temperature of the film from anatase to rutile was shifted from 650 to 700 °C by addition
of trehalose to the sol. 相似文献
175.
Eiji Tsurumaki Yasuhide Inokuma Shanmugam Easwaramoorthi Dr. Jong Min Lim Dongho Kim Prof. Dr. Atsuhiro Osuka Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(1):237-247
Effective peripheral fabrication methods of meso‐aryl‐substituted subporphyrins were explored for the first time. Hexabrominated subporphyrins 2 were prepared quantitatively from the bromination of subporphyrins 1 with bromine. Hexaphenylated subporphyrins 3 and hexaethynylated subporphyrins 4 and 5 were synthesized by Suzuki–Miyaura coupling and Stille coupling, respectively, in good yields. X‐ray crystal structures of 2 b , 3 b , 4 b , and 5 a revealed preservation of the bowl‐shaped bent structures with bowl depths similar to that of 1 . Hexaethynylated subporphyrins exhibit large two‐photon‐absorption cross‐sections due to effective delocalization of the conjugated network to the ethynyl substituents. 相似文献
176.
Shanmugam Easwaramoorthi Dr. Jae‐Yoon Shin Sung Cho Dr. Pyosang Kim Yasuhide Inokuma Eiji Tsurumaki Atsuhiro Osuka Prof. Dr. Dongho Kim Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(44):12005-12017
Donor–acceptor systems based on subporphyrins with nitro and amino substituents at meta and para positions of the meso‐phenyl groups were synthesized and their photophysical properties have been systematically investigated. These molecules show two types of charge‐transfer interactions, that is, from center to periphery and periphery to center depending on the peripheral substitution, in which the subporphyrin moiety plays a dual role as both donor and acceptor. Based on the solvent‐polarity‐dependent photophysical properties, we have shown that the fluorescence emission of para isomers originates from the solvatochromic, dipolar, symmetry‐broken, and relaxed excited states, whereas the non‐solvatochromic fluorescence of meta isomers is of the octupolar type with false symmetry breaking. The restricted meso‐(4‐aminophenyl) rotation at low temperature prevents the intramolecular charge‐transfer (ICT)‐forming process. The two‐photon absorption (TPA) cross‐section values were determined by photoexcitation at 800 nm in nonpolar toluene and polar acetonitrile solvents to see the effect of ICT on the TPA processes. The large enhancement in the TPA cross‐section value of approximately 3200 GM (1 GM=10?50 cm4 s photon?1) with donor–acceptor substitution has been attributed to the octupolar effect and ICT interactions. A correlation was found between the electron‐donating/‐withdrawing abilities of the peripheral groups and the TPA cross‐section values, that is, p‐aminophenyl>m‐aminophenyl>nitrophenyl. The increased stability of octupolar ICT interactions in highly polar solvents enhances the TPA cross‐section value by a factor of approximately 2 and 4, respectively, for p‐amino‐ and m‐nitrophenyl‐substituted subporphyrins. On the other hand, the stabilization of the symmetry‐broken, dipolar ICT state gives rise to a negligible impact on the TPA processes. 相似文献
177.
Eiji Akiyama Zuogui Zhang Yoshimi Watanabe Kaneaki Tsuzaki 《Journal of Solid State Electrochemistry》2009,13(2):277-282
Effects of severe plastic deformation on the corrosion behaviors of Al alloys containing precipitates have been investigated.
Al and its alloys were severely deformed by equal-channel angular pressing (ECAP) processes and the corrosion behaviors of
the Al alloys were evaluated by means of potentiodynamic polarization in a neutral buffer solution containing 0.002 M chloride
ion. Introduction of huge plastic deformation to both of Al-5.4 wt% Ni and Al-5 wt% Cu alloys increased pitting potential.
In contrast, ECAP treatment of 4N pure Al resulted in a decrease in open circuit potential, slight increase of passive current
and shift of pitting potential to the negative direction. The influence of the change in microstructures caused by severe
plastic deformation was investigated.
Contribution to the Fall Meeting of the European Materials Research Society, Symposium D: 9th International Symposium on Electrochemical/Chemical
Reactivity of Metastable Materials, Warsaw, 17th-21st September, 2007 相似文献
178.
Shape- and size-controlled syntheses of metal nanoparticles have been achieved by galvanic displacement reaction between an aqueous solution of metal salt and Cu foil substrate. In particular, cubic and spheric nanoparticles of Pt (Au) with a fairly narrow size distribution were produced by reacting K(2)PtCl(4) (HAuCl(4)) with a Cu foil in an aqueous medium with and without CuCl(2) under different reaction conditions (e.g., different concentrations and reaction times). In conjunction with the substrate-enhanced electroless deposition (SEED) technique (Qu, L.; Dai, L. J. Am. Chem. Soc. 2005, 127, 10806), the shape/size-controlled syntheses have been successfully exploited to site-selectively deposit these metal nanoparticles onto the outerwall, innerwall, or end-tip of carbon nanotubes (CNTs). Asymmetric sidewall modification by attaching the innerwall and outerwall of CNTs with metal nanoparticles of different shapes was also achieved. Furthermore, it was demonstrated that the nanotube-supported Pt nanoparticles could be converted into hollow Au nanoboxes by galvanic displacement of Pt with Au. These CNT-supported metal nanoparticles were shown to possess interesting optical and electrocatalytic properties. 相似文献
179.
Ikeda M Tanaka Y Hasegawa T Furusho Y Yashima E 《Journal of the American Chemical Society》2006,128(21):6806-6807
We describe the construction of the first double-stranded metallosupramolecular helical polymers. We designed and synthesized a supramolecular duplex comprised of complementary m-terphenyl-based strands bearing a chiral amidine or achiral carboxylic acid together with two pyridine groups at the four ends. Supramolecular polymerization of the duplex with cis-PtPh2(DMSO)2 in 1,1,2,2-tetrachloroethane produced the double-stranded metallosupramolecular polymer with a controlled helicity of which the two complementary metallostrands are intertwined through the amidinium-carboxylate salt bridges. The structures and hydrodynamic dimensions of the metallosupramolecular polymers were characterized by 1H NMR, diffusion-ordered NMR, dynamic light scattering, absorption, and CD measurements. The polymeric structure was also visualized by atomic force microscopy. 相似文献
180.
Koumura N Wang ZS Mori S Miyashita M Suzuki E Hara K 《Journal of the American Chemical Society》2006,128(44):14256-14257
We designed and synthesized new alkyl-functionalized organic dyes, MK-1 and MK-2, for dye-sensitized solar cells (DSSCs). Based on the MK-2 dye, a high performance of efficiency (eta, 7.7%; short-circuit current density Jsc = 14.0 mA cm-2, open-circuit voltage Voc = 0.74 V, and fill factor FF = 0.74) was achieved under AM 1.5 G irradiation (100 mW cm-2). Remarkably, the relatively higher Voc for DSSCs based on MK-1 and MK-2 dyes, which have long alkyl chains, were observed among the organic dyes caused by the increasing of the electron lifetime in the conduction band of TiO2. Our molecular design of alkyl-functionalized dyes strongly suggests the promising performance of molecular photovoltaics based on organic dyes. 相似文献