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191.
Kuga Yoshikazu Okauchi Keiko Takeda Daiki Ohira Yuichi Ando Koji 《Journal of nanoparticle research》2001,3(2-3):175-183
Size distribution measurements and classification tests by a low pressure differential mobility analyzer (LPDMA) for nanometer-sized silver particles and cesium iodide particles under low pressure conditions (123–300 Torr) were performed using a transmission electron microscope (TEM) and the tandem DMA technique. When the ratio of the sheath gas flow rate and the aerosol gas flow rate was set at 5 : 1, the targeted sizes calculated from the classification voltage applied to the LPDMA at 160 Torr are found to be in good correlation with the count mean Feret diameter obtained from the TEM observation of the particles collected after a classification ranging from 6 to 25 nm, although the targeted sizes set by the LPDMA were approximately 15% greater than the count mean Feret diameter measured by the TEM after classification. The geometric standard deviations of DMA-classified particles measured by TEM and those obtained from the tandem DMA method ranged from 1.08 to 1.17 and from 1.05 to 1.13, respectively. They were slightly greater than the ideal geometric standard deviations (1.05) of the particles classified with the LPDMA, which was calculated by neglecting the broadening effects due to Brownian diffusion. We experimentally demonstrated the validity of our LPDMA system for size measurements and classification of the nanometer-sized particles under low pressure conditions. 相似文献
192.
Koji Nuida Satoshi Fujitsu Manabu Hagiwara Takashi Kitagawa Hajime Watanabe Kazuto Ogawa Hideki Imai 《Designs, Codes and Cryptography》2009,52(3):339-362
It has been proven that the code lengths of Tardos’s collusion-secure fingerprinting codes are of theoretically minimal order
with respect to the number of adversarial users (pirates). However, the code lengths can be further reduced as some preceding
studies have revealed. In this article we improve a recent discrete variant of Tardos’s codes, and give a security proof of
our codes under an assumption weaker than the original Marking Assumption. Our analysis shows that our codes have significantly
shorter lengths than Tardos’s codes. For example, when c = 8, our code length is about 4.94% of Tardos’s code in a practical setting and about 4.62% in a certain limit case. Our
code lengths for large c are asymptotically about 5.35% of Tardos’s codes.
A part of this work was presented at 17th Applied Algebra, Algebraic Algorithms, and Error Correcting Codes (AAECC-17), Bangalore,
India, December 16–20, 2007. 相似文献
193.
Koji Kano Ryuhei Nishiyabu 《Journal of inclusion phenomena and macrocyclic chemistry》2002,44(1-4):355-359
A general mechanism for chiral recognition by native and modified cyclodextrins hasbeen proposed by reconsidering the data reported so far. Cyclodextrins in aqueoussolution adopt asymmetrically twisted structures, which seems to be the origin of chiralrecognition. 相似文献
194.
Koji Nagahama Kanae Fujiura Shunsuke Enami Tatsuro Ouchi Yuichi Ohya 《Journal of polymer science. Part A, Polymer chemistry》2008,46(18):6317-6332
Starburst triblock copolymers consisting of 8‐arm poly(ethylene glycol) (8‐arm PEG) and biodegradable poly(L ‐lactide) (PLLA) or its enantiomer poly(D ‐lactide) (PDLA), 8‐arm PEG‐b‐PLLA‐b‐PEG ( Stri‐L ), and 8‐arm PEG‐b‐PDLA‐b‐PEG ( Stri‐D ) were synthesized. An aqueous solution of a 1:1 mixture ( Stri‐Mix ) of Stri‐L and Stri‐D assumed a sol state at room temperature, but instantaneously formed a physically crosslinked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high‐storage modulus (9.8 kPa) at 37 °C. Interestingly, once formed at the transition temperature, the hydrogel was stable even after cooling below the transition temperature. The hydrogel formation process was irreversible because of the formation of stable stereocomplexes. In aqueous solution, gradual hydrolytic erosion was observed because of degradation of the hydrogel. The combination of rapid temperature‐triggered irreversible hydrogel formation, high‐mechanical strength, and degradation behavior render this polymer mixture system suitable for use in injectable biomedical materials, for example, as a drug delivery system for bioactive reagents or a biodegradable scaffold for tissue engineering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6317–6332, 2008 相似文献
195.
Koji Kita Sho Suzuki Tomonori Nishimura Akira Toriumi 《Applied Surface Science》2008,254(19):6100-6105
Two approaches to control high-k/Ge interface qualities were investigated. The first approach was using high-k materials that are intimate with Ge. These Ge-intimate high-k materials should have moderate reactivity with Ge to form an amorphized interface that will reduce the interface defects and will suppress the GeO desorption at the interface. The second approach was modifying the annealing processes by using a cap layer to block GeO out-diffusion. We found that Si works as the cap layer very efficiently. By combining those two approaches, we achieved fairly good high-k/Ge metal-insulator-semiconductor (MIS) characteristics with LaYO3 as the Ge-intimate high-k material, and a NiSiX electrode as the cap layer. These results provide us an important guide for controlling the high-k/Ge interface properties. 相似文献
196.
Gas-phase ozone was continuously measured by using the chemiluminescent reaction between indigo-5,5′-disulphonate and ozone. A detection limit of 0.4 ppb (v/v) was obtained using a reaction cell of 0.7 ml at a sampling rate of 15.0 ml min?1. The method was applied to the monitoring of ozone in the atmosphere. 相似文献
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200.
Three novel naphthoquinone-based heterocyclic pigments, 2-methyl-3-[(1-methyl-1H-imidazol-2-yl)thio-1,4-naphthalenedione, (4-methyl-4H-1,2,4-triazol-3-yl)thio-1,4-naphthalenedione, and (1-methyl-1H-tetrazol-5-yl)thio]-1,4-naphthalenedione, are synthesized, and their optical properties in both solution and solid states are investigated. Depending on the heteroarylthio ring in the pigment, variation in optical properties is observed, e.g. characteristic colours for each pigment in the solution and solid states. The achiral pigment containing the 1-methyl-1H-tetrazol-5-yl ring exhibits a chiral space group and a CD signal in the solid state. 相似文献