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181.
Chemical effects associated with6Li (n,α)T reaction in Lithium compounds were studied by observing a Mössbauer spectrum for the Mössbauer nuclides introduced in the lithium compounds. The large difference between the effects of lithium carbonate and oxalate was compared with the results obtained in the emission Mössbauer spectra of57Co-labelled triscarbonatocobaltate(III) and trisoxalatocobaltate(III), in which the former shows much less reducing effect on the produced57Fe species than the latter. 相似文献
182.
S. Iijima F. Mizutani O. Niwa N. Matsumoto Y. Sunatsuki M. Kojima 《Hyperfine Interactions》2005,166(1-4):397-402
The spin-crossover behaviors of mixed-valence iron compounds [FeIIH3L][FeIIIL](NO3)2 (1) and [FeIIH3LMe][FeIIILMe](NO3)2 (2) have been investigated by 57Fe Mössbauer spectroscopy, where H3L is a hexadentate N6 tripod ligand containing three imidazole groups and H3LMe is its 2-methylimidazole derivative. Deconvolution analyses of the Mössbauer spectra revealed that a two-step SCO (LS FeII–LS FeIII→HS FeII–LS FeIII→HS FeII–HS FeIII) proceeds in each compound on elevating the temperature. Compound 2 exhibited lower spin-transition temperatures than 1. “Frozen-in effect” was observed below 120 and 50 K for 1 and 2, respectively. 相似文献
183.
Tomohito Ogura Tomoya Higashihara Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2009,47(13):3362-3369
A positive‐type photosensitive polyimide (PSPI) based on poly(amic acid) (PAA), a crosslinker 1,1,1‐tris{4‐[2‐(vinyloxy)ethoxy]phenyl}ethane (TVPE), a photoacid generator (PAG) (5‐propylsulfonyloxyimino‐5H‐thiophen‐2‐ylidene)‐2‐(methylphenyl)acetonitrile (PTMA), and a thermobase generator (TBG) t‐butyl 2,6‐dimethylpiperidine‐1‐carboxylate (BDPC) has been developed as a promising material in microelectronics. The PAA was prepared from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐oxydianiline (ODA) in dimethyl sulfoxide (DMSO). The PSPI, consisting of PAA (69 wt %), TPVE (21 wt %), PTMA (3 wt %), and BDPC (7 wt %), showed high sensitivity of 21 mJ/cm2 and a high contrast of 6.8 when it was exposed to a 436‐nm line (g‐line), postbaked at 90 °C for 5 min, and developed with 1.69 wt % TMAHaq. A clear positive image of 8 μm line and space pattern was printed on film, which was exposed to 50 mJ/cm2 of g‐line by a contact printing mode and fully converted to the corresponding polyimide (PI) pattern on heating at 200 °C, confirmed by FTIR spectroscopy. Thus, this system will be a good candidate for next generation PSPIs. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3362–3369, 2009 相似文献
184.
Kazuhiro Kobayashi Sunyoung Kim Masakazu Kojima 《Applied Mathematics and Optimization》2008,58(1):69-88
Exploiting sparsity has been a key issue in solving large-scale optimization problems. The most time-consuming part of primal-dual
interior-point methods for linear programs, second-order cone programs, and semidefinite programs is solving the Schur complement
equation at each iteration, usually by the Cholesky factorization. The computational efficiency is greatly affected by the
sparsity of the coefficient matrix of the equation which is determined by the sparsity of an optimization problem (linear
program, semidefinite program or second-order cone program). We show if an optimization problem is correlatively sparse, then the coefficient matrix of the Schur complement equation inherits the sparsity, and a sparse Cholesky factorization
applied to the matrix results in no fill-in.
S. Kim’s research was supported by Kosef R01-2005-000-10271-0 and KRF-2006-312-C00062. 相似文献
185.
We investigated preliminary acute toxicity and primary skin irritation of nine pyrrolidone derivatives which had been previously developed as transdermal penetration enhancers. The acute toxicity was observed at a dose of 500 mg/kg after intraperitoneal administration in mice. Their primary skin irritations were examined with rabbit dorsal skin. 1-Lauryl-2-pyrrolidone induced the most severe irritation among the derivatives. Pyrrolidone derivatives having methyl group and methyloxycarbonyl group caused little irritation. The primary irritation indices of pyrrolidone derivatives were not relative to their accumulations in the skin but to their enhancing effects. In conclusion, 1-hexyl-4-methyloxycarbonyl- and 1-lauryl-4-methyloxycarbonyl-2-pyrrolidone are suggested to be adequate enhancers, judging from the balance of their enhancing activity and irritation. 相似文献
186.
N-Benzyl-D-glucamine dithiocarbamate (BGD), N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD) were compared for their relative efficacies in the distribution and excretion of cadmium in mice exposed to cadmium. Mice were injected intraperitoneally with 109CdCl2 (1 mg of Cd/kg and 2 microCi of 109Cd/one animal). Three days later, they were injected with chelating agents (400 mumol/kg) every other day for 2 weeks. After injections of BGD and HBGD, cadmium was excreted mainly in the feces through the bile, and the fecal excretion of cadmium by HBGD was significantly higher than that by BGD or CBGD. These chelating agents increased the urinary excretion of cadmium to a small extent. The hepatic cadmium content was decreased only after HBGD injection. Also, the injection of HBGD caused a much greater decrease in renal cadmium content than did BGD or CBGD. These chelating agents did not result in the redistribution of cadmium to the brain, testes, or heart. The growth of mice was only slightly retarded by injections of these chelating agents. The results of this study indicate that the injection of HBGD to mice pretreated with cadmium can remove cadmium from the body, mainly through fecal excretion, without redistribution of cadmium to other tissues such as the brain, testes, and heart, more effectively than BGD or CBGD. 相似文献
187.
Kazuo Furihata Sakurako Shimotakahara Yoichi Shibusawa Mitsuru Tashiro 《Magnetic resonance in chemistry : MRC》2009,47(11):971-976
An efficient pulse sequence for observing the ligand signals resonating close to the water signal has been developed by incorporating the WET technique into the saturation transfer difference pulse sequence. Although several pulse sequences have been developed for observing a ligand binding with a protein receptor, the ligand signals resonating close to the water were undetectable owing to the interference of the huge water signal in the samples containing 95% 1H2O. On the point of sample preparation, it is preferable to avoid the solvent exchange in the protein samples. In the proposed pulse sequence, a WET sequence is incorporated for the selective suppression of the water resonance. The efficient water suppression and the clear observation of the bound ligand signals close to the water have been demonstrated using the lysozyme‐glucose complex. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
188.
Iron mixed-valence complex, (n-C3H7)4N[FeIIFeIII(dto)3] (dto = C2O2S2) shows a new-type of phase transition coupled with spin and charge around 120 K, where the charge transfer between the FeII and FeIII sites occurs reversibly, and shows the ferromagnetic transition at 7 K. To investigate the magnetic structure and its dimensionality of (n-C3H7)4N[FeIIFeIII(dto)3], we have synthesized a mixed crystal system, (n-C3H7)4N[FeII1?xZnIIxFeIII(dto)3], and measured its magnetic properties. In this system, the magnetic moment is reduced with increasing of Zn ratio. Moreover, the ferromagnetic interaction changes to the antiferromagnetic one and the remnant magnetization disappears between x = 0.48 and 0.96, while the charge transfer between the FeII and FeIII sites disappears above x = 0.26. In this paper, we present the magnetic dilution effect on the charge transfer phase transition and the ferromagnetic transition by means of magnetic susceptibility measurement and 57Fe Mössbauer spectroscopy. 相似文献
189.
Noriyuki Kida Masanori Hikita Izuru Kashima Masaya Enomoto Miho Itoi Norimichi Kojima 《Polyhedron》2009,28(9-10):1694-1697
A photo-sensitive organic–inorganic hybrid system (SP)[FeIIFeIII(dto)3] (SP = spiropyran, dto = C2O2S2), has recently been developed, where the photo-isomerization of the intercalated spiropyran in solid state triggers the change of the magnetic properties, including the ferromagnetic transition temperature from 5 to 22 K. We performed 57Fe Mössbauer measurement in order to probe the microscopic states of iron ions in (SP)[FeIIFeIII(dto)3] and have investigated the photo-induced effect on them. The sample without UV-irradiation shows the charge transfer phase transition between 200 and 70 K and the higher and lower temperature phases coexist below 70 K, whereas the UV-irradiated sample does not undergo the charge transfer phase transition and the higher temperature phase is stable between 200 and 6 K. 相似文献
190.
Katsuhisa Mizoguchi Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2008,46(15):4949-4958
A negative‐type photosensitive poly(phenylene ether) (PSPPE) based on poly(2,6‐dimethyl‐1,4‐phenylene ether) (PPE), a novel crosslinker 4,4′‐methylene‐bis [2,6‐bis(methoxymethyl)phenol] (MBMP) having good compatibility with PPE, and diphenylidonium 9,10‐dimethoxy anthracene‐2‐sulfonate (DIAS) as a photoacid generator (PAG) has been developed. This resist consisting of PPE (73 wt %), MBMP (20 wt %) and DIAS (7 wt %) showed a high sensitivity (D0.5) of 58 mJ/cm2 and a contrast (γ0.5) of 9.5 when it was exposed to i‐line (365 nm wavelength light), postexposure baked at 145 °C for 10 min, and developed with toluene at 25 °C. A fine negative image featuring 6 μm line‐and‐space pattern was obtained on the film exposed to 300 mJ/cm2 of i‐line by a contact‐printed mode. The resulting polymer film cured at 300 °C for 1 h under nitrogen had a low dielectric constant (ε = 2.46) comparable to that of PPE and a higher Tg than that of PPE. In addition, the cured PSPPE film was pretty low water absorption (<0.05%) as same as PPE. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4949–4958, 2008 相似文献