排序方式: 共有59条查询结果,搜索用时 15 毫秒
1.
Nobuyuki Otozawa Rio Hamajima Masataka Yoshioka Raito Kato Arisa Tanaka Hiroto Fukuma Toshiki Terao Kei Manabe Syuji Fujii Yoshinobu Nakamura Atsushi Takahara Tomoyasu Hirai 《Journal of polymer science. Part A, Polymer chemistry》2020,58(14):1960-1964
This study investigates the effect of ionic liquids (ILs) on the anionic polymerization of methyl methacrylate (MMA). Polymethyl methacrylate (PMMA), an isotactic polymer, is prepared by anionic polymerization at a high reaction temperature with an IL that acts as both solvent and additive. The most plausible reaction mechanism is determined using 1H NMR and Fourier-transform infrared spectroscopy. The electrostatic interaction between MMA and the IL increases the apparent steric hindrance in MMA, resulting in the isotactic PMMA. 相似文献
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Akter Sharmin Tanabe Tomoki Maejima Satoshi Kawauchi Satoko Sato Shunichi Hinoki Akinari Aosasa Suefumi Yamamoto Junji Nishidate Izumi 《Optical Review》2016,23(2):354-359
Optical Review - To quantify the changes in optical properties of in vivo rat liver tissue, we applied diffuse reflectance spectroscopy (DRS) system using single-reflectance fiber probe during... 相似文献
4.
Chitrakar R Tezuka S Sonoda A Sakane K Ooi K Hirotsu T 《Journal of colloid and interface science》2005,290(1):45-51
Adsorptive properties of MgMn-3-300 (MgMn-type layered double hydroxide with Mg/Mn mole ratio of 3, calcined at 300 degrees C) for phosphate were investigated in phosphate-enriched seawater with a concentration of 0.30 mg-P/dm3. It showed the highest phosphate uptake from the seawater among the inorganic adsorbents studied (hydrotalcite, calcined hydrotalcite, activated magnesia, hydrous aluminum oxide, manganese oxide (delta-MnO2)). The phosphate uptake by MgMn-3-300 reached 7.3 mg-P/g at an adsorbent/solution ratio of 0.05 g/2 dm3. The analyses of the uptakes of other constituents (Na+, K+, Ca(+, Cl-, and SO(2-)4) of seawater showed that the adsorbent had a markedly high selectivity for the adsorption of phosphate ions. Effects of initial phosphate concentration, temperature, pH, and salinity on phosphate uptake were investigated in detail by a batch method. The phosphate uptake increased slightly with an increase in the adsorption temperature. The adsorption isotherm followed Freundlich's equation with constants of logK(F)=1.25 and 1/n=0.65, indicating that it could effectively remove phosphate even from a solution of markedly low phosphate concentration as well as with large numbers of coexisting ions. The pH dependence showed a maximum phosphate uptake around pH 8.5. The pH dependence curve suggested that selective phosphate adsorption progresses mainly by the ion exchange of HPO(2-)4. The study on the effect of salinity suggested the presence of two kinds of adsorption sites in the adsorbent: one nonspecific site with weak interaction and one specific site with strong interaction. The effective desorption of phosphate could be achieved using a mixed solution of 5 M NaCl + 0.1 M NaOH (1 M = 1 mol/dm3), with negligible dissolution of adsorbent. The adsorbent had high chemical stability against the adsorption/desorption cycle; it kept a good phosphate uptake even after the repetition of the seventh cycle. 相似文献
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Xianqing Piao Xianmin Zhang Yuichi Mori Masayuki Koishi Akinari Nakaya Shinichiro Inoue Isao Aoki Akira Otomo Shiyoshi Yokoyama 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):47-54
Electro‐optic side‐chain polymers have been synthesized by the post‐functionalization of methacrylate isocyanate polymers with novel phenyl vinylene thiophene vinylene bridge (FTC) nonlinear optical chromophores. For this application, FTC‐based chromophores were modified in their electronic donor structure, exhibiting much larger molecular hyperpolarizabilities compared with the benchmark FTC. Of these new chromophores, absorption spectra, hyper‐Rayleigh scattering experiment, and thermal analysis were carried out to confirm availability as effective nonlinear optical units for electro‐optic side‐chain polymers. The electro‐optic coefficients (r33) of obtained polymers were investigated in the process of in situ poling by monitoring the temperature, current flow, poling field, and electro‐optic signal. Compared with the nonsubstituted analogue, benxyloxy modified FTC chromophore significantly achieved higher nonlinear optical property, exhibiting molecular hyperpolarizability at 1.9 μm of 4600 × 10?30 esu and an r33 value of 150 pm/V at the wavelength of 1.31 μm. Synthesized electro‐optic polymers showed high glass transition temperature (Tg), so that the temporal stability examination exhibited >78% of the electro‐optic intensity remaining at 85 °C over 500 h. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
6.
Akinari Hoshi 《Journal of Number Theory》2011,131(11):2135-2150
Let m?−1 be an integer. We give a correspondence between integer solutions to the parametric family of cubic Thue equations
X3−mX2Y−(m+3)XY2−Y3=λ 相似文献
7.
Akinari Nakagawa 《Optical Review》2003,10(1):47-52
It has been noticed that observed spectral line profiles by the SOHO ultraviolet coronagraph spectrometer (SOHO/UVCS) are contaminated by a so-called detector effect, and an iterative correction of observed profiles by convolution with a zero-integral function has been employed to remove this unwanted effect on UVCS detectors. It is shown here that this iteration procedure using a zero-integral function can be replaced by an only-once application of convolution. For zero-integral functions of exp[- |x|/L]-type, the convolution function in this method is proved to have exactly the same, but narrower (steeper), functional form as the original one. These results are also valid, with some modifications, for the discrete case used in numerical calculation. 相似文献
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Y. Nagame I. Nishinaka Y. L. Zhao K. Tsukada S. Ichikawa Z. Qin H. Ikezoe Y. Oura K. Sueki H. Nakahara M. Tanikawa T. Ohtsuki S. Goto H. Kudo Y. Hamajima K. Takamiya K. Nakanishi H. Baba 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):97-101
The correlation among the fission threshold energy, the scission configuration and the mass yield distribution has been studied
in proton-induced fission of light actinides. It was found that there exist at least two fission paths from the threshold
region to the scission. The elongated scission configuration is related with the fission process that goes over a higher threshold
energy and results in a symmetric mass division mode, while the compact scission configuration with the process that experiences
a lower threshold and ends up with an asymmetric mass division mode. 相似文献
9.
T. Muroyama A. Shinohara T. Saito A. Yokoyama K. Takamiya S. Morimoto K. Nakanishi H. Baba T. Miura Y. Hamajima T. Kaneko H. Muramatsu S. Kojima M. Furukawa 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):159-163
Annihilation γ-rays of π0 and pionic X-rays were measured in the gas mixtures of H2+Z and CH4+Z systems (Z=He, Ne, Ar and Kr). Pion capture probability of hydrogen atom was obtained from the annihilation γ-ray counts
and the capture probability of Z atom was obtained from the pionic X-ray intensities. Transfer rates were determined from
the data based on a combined large mesomolecular model. The transfer rates obtained were smaller than the systematics of the
Russian group. Difference in the transfer rate between the gas and the liquid phases was found by a comparison of the present
results with our previous ones. 相似文献
10.
Kaneko R Hattori S Furuta S Hamajima M Hirata Y Watanabe K Seno H Ishii A 《Journal of mass spectrometry : JMS》2006,41(6):810-814
The Aconitum species (Ranunculaceae) are widely distributed in northern Asia and North America. Their roots are popularly used in herbal medicines in China and Japan. Many cases of accidental, suicidal and homicidal intoxication with this plant have been reported; some of these were fatal because the toxicity of Aconitum is very high. It is thus important to detect and quantify Aconitum alkaloids in body fluids, with high sensitivity. We have developed a simple and sensitive method for measuring four kinds of Aconitum alkaloids (aconitine, hypaconitine, jesaconitine and mesaconitine) by LC/electrospray (ESI)-time-of-flight (TOF)-MS. For all of them, only molecular ions were observed at an orifice voltage of 75 V; at 135 V, base peaks corresponding to [M - 60 + H]+ ions were observed. These four compounds and methyllycaconitine (internal standard) in human plasma samples were purified by solid-phase extraction. The four extracted compounds were completely separated in mass chromatograms; the calibration curves showed good linearity in the range 10-300 ng/ml, and the detection limits were estimated to be 0.2-0.5 ng/ml. Using our method, we also determined the amounts of these compounds in tuber samples. The present method is applicable in clinical and forensic toxicology. 相似文献