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1.
Hidetaka Tobita 《Journal of Polymer Science.Polymer Physics》2004,42(14):2801-2812
The matrix formula developed in the context of heterochain theory, M?w = M?wp + WF ( I ? M )?1 S , was applied to describe the molecular weight development during free‐radical multicomponent polymerization. All of the required probabilistic parameters are expressed in terms of the kinetic‐rate constants and the various concentrations associated with them. In free‐radical polymerization, the number of heterochain types, N, needs to be extrapolated to infinity, and such extrapolation is conducted with only three different N values. This matrix formula can be used as a benchmark test if other approximate approaches can give reasonable estimates of the weight‐average molecular weights. The moment equations with the average pseudo‐kinetic‐rate constants for branching and crosslinking reactions may provide poor estimates when the copolymer composition drift during polymerization is very significant. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2801–2812, 2004 相似文献
2.
Hidetaka Yuge Toschitake Iwamoto 《Journal of inclusion phenomena and macrocyclic chemistry》1992,14(3-4):217-235
The crystal structures of the four title clathrate compounds Cd(NH3)2Cd(CN)4 · 2C6H6,I, Cd(NH3)2Cd(CN)4 · 2C6H5NH2,II, Cd(NH2CH2CH2NH2)Cd(CN)4 · 2 C6H5NH2,III, and Cd(C6H5NH2)2Cd(CN)4 · 0.5C6H5NH2,IV, have been analyzed by single crystal X-ray diffraction methods. CompoundI crystallizes in the monoclinic space groupC2/c,a = 12.063(2),b = 12.174(2),c = 14.621(1) Å,β = 90.976(9)°,Z = 4,R = 0.042 for 2388 reflections;II: monoclinic C2/c,a = 12.1951(9),b = 12.078(1),c = 14.6921(7) Å,β = 93.436(5)°,Z = 4,R = 0.039 for 2374 reflections;III: monoclinicCc,a = 11.027(1),b = 12.0767(9),c = 15.837(1) Å,β = 92.059(9)°,Z = 4,R = 0.041 for 2883 reflections; andIV: monoclinicP21/n,a = 15.169(2),b = 16.019(2),c = 8.866(1) Å,β = 95.73(1)°,Z = 4,R = 0.052 for 3612 reflections. The three-dimensionalcatena-[diamminecadmium(II) tetra-μ-cyanocadmate(II)] hosts ofI andII are substantially isostructural to that of the already known Hofmann-Td-type Cd(NH3)2Hg(CN)4 · 2C6H6. The three-dimensional en-Td-typecatena-[catena-μ-ethylenediaminecadmium(II) tetra-μ-cyanocadmate(II)] host ofIII, reinforced by the catena-μ-en linking between the octahedral Cd atoms, accommodates the aniline as the guest with a monoclinic distortion from the tetragonal symmetry of the previously reported en-Td-type benzene clathrate. InIV dual behavior of aniline, one as the unidentate ligand in the three-dimensional host and the other as the guest in the cage-like cavity, has been demonstrated. 相似文献
3.
Hidetaka KogaEiji Wada 《Tetrahedron letters》2003,44(4):715-719
An efficient catalytic double asymmetric induction during the tandem transetherification-intramolecular hetero Diels-Alder reaction has been developed. The enantioselective tandem reaction of methyl (E)-4-methoxy-2-oxo-3-butenoate with rac-6-methyl-5-hepten-2-ol has been achieved to provide methyl (2R,4aS,8aR)-3,4,4a,8a-tetrahydro-2,5,5-trimethyl-2H,5H-pyrano[4,3-b]-pyran-7-carboxylate in good yield with effective kinetic resolution (up to 95% selectivity), high diastereoselectivity (up to 92% de), and high enantioselectivity (up to 97% ee) in the presence of (S,S)-tert-Bu-bis(oxazoline)-Cu(SbF6)2 and 5 Å molecular sieves. 相似文献
4.
Anas A Akita H Harashima H Itoh T Ishikawa M Biju V 《The journal of physical chemistry. B》2008,112(32):10005-10011
Strand breakages and nucleobase damages in plasmid DNA (pDNA) by CdSe-ZnS quantum dots (QDs) are investigated under different conditions of photoactivation. Here, streptavidin functionalized CdSe-ZnS QDs are conjugated to biotinylated pDNA, and photosensitized strand breakages and nucleobase damages in the conjugates are investigated using atomic force microscopy (AFM) imaging, gel electrophoreses analyses, and assay of reactive oxygen intermediates (ROI). Also, reactions of photoactivated pDNA-QD conjugates with base excision repair enzymes such as formamidopyrimidine glycosylase (Fpg) and endonuclease III (Endo III) show damages of purine and pyrimidine bases. The base excision repair enzymes recognize and remove the damaged bases. The base excision reactions of photoactivated pDNA-QD conjugates resulted in pDNA strand breakages, which appeared as sheared bands in agarose gel images. On the basis of AFM imaging, reactions of Fpg and Endo III with damaged pDNA, ROI assay, and literature reports, we attribute the breakage and damage of pDNA to its reactions with ROI. The production of ROI by photoactivated QDs is confirmed by nitroblue tetrazolium (NBT) assay. The current work shows that photoactivation of QD-conjugated nucleic acids for an extended period of time is not favorable for their stability. On the other hand, photoinduced production of ROI by QDs is an emerging research area with potential applications in the photodynamic therapy of cancer. In this regard, photosensitized damage of pDNA observed in the current work shows possibilities of QDs in nucleus-targeted photodynamic therapy. 相似文献
5.
A specific HPLC method for the simultaneous determination of YM928, a novel noncompetitive AMPA receptor antagonist, and its demethylated metabolite (YM-58875) in rat, dog and monkey plasma was developed and validated. The method utilized multiple-step liquid-liquid extraction followed by a reversed-phase HPLC with UV detection at 275 nm. No interfering peaks were observed at the retention times of YM928, YM-58875 or internal standard. The validated quantitation range was 5-5000 ng/mL for both YM928 and YM-58875 when 1 mL of the plasma sample was used. The intra- and inter-day precision was less than 5.3 and 2.5% for YM928, and 3.7 and 2.3% for YM-58875, respectively. The intra- and inter-day accuracies were -8.7-5.3% and 0.7-1.9% for YM928, and -10.0-6.1% and 1.3-3.4% for YM-58875, respectively. The mean recoveries in the extraction process were 52.7-62.8%. The utility of this analytical method was demonstrated by the investigation of the pharmacokinetics of the unchanged drug and its metabolite in preclinical studies. 相似文献
6.
Dr. Kenichi Kato Dr. Hidetaka Kasai Dr. Akihiro Hori Prof. Dr. Masaki Takata Prof. Dr. Hiroshi Tanaka Prof. Dr. Susumu Kitagawa Akira Kobayashi Dr. Nobuki Ozawa Prof. Dr. Momoji Kubo Dr. Hidekazu Arikawa Prof. Dr. Tatsuya Takeguchi Dr. Masaaki Sadakiyo Prof. Dr. Miho Yamauchi 《化学:亚洲杂志》2016,11(10):1537-1541
The layered P2‐NaxMO2 (M: transition metal) system has been widely recognized as electronic or mixed conductor. Here, we demonstrate that Co vacancies in P2‐NaxCoO2 created by hydrogen reductive elimination lead to an ionic conductivity of 0.045 S cm?1 at 25 °C. Using in situ synchrotron X‐ray powder diffraction and Raman spectroscopy, the composition of the superionic conduction phase is evaluated to be Na0.61(H3O)0.18Co0.93O2. Electromotive force measurements as well as molecular dynamics simulations indicate that the ion conducting species is proton rather than hydroxide ion. The fact that the Co‐stoichiometric compound Nax(H3O)yCoO2 does not exhibit any significant ionic conductivity proves that Co vacancies are essential for the occurrence of superionic conductivity. 相似文献
7.
8.
In this paper we are concerned with solutions, in particular with univalent solutions, of the Loewner differential equation
associated with non-normalized subordination chains on the Euclidean unit ball B
n
in
\mathbbCn{\mathbb{C}^n}. The main result is a generalization to higher dimensions of a well known result due to Becker. Various particular cases
of this result have been recently obtained for subordination chains with normalization Df(0,t)=etIn{Df(0,t)=e^tI_n} or Df(0, t) = e
tA
, t ≥ 0, where
A ? L(\mathbbCn,\mathbbCn){A\in L(\mathbb{C}^n,\mathbb{C}^n)}. We also determine the form of the standard solutions to the Loewner differential equation associated with generalized spirallike
mappings. In the last section we obtain the form of the solution in the presence of coefficient bounds. 相似文献
9.
Sohei Okazaki Noriaki Okazaki Hidetaka Sugaya Ryota Takahashi Yuji Matsumoto Hideomi Koinuma Tetsuya Hasegawa 《Applied Surface Science》2006,252(7):2615-2621
We developed a scanning microwave microscope (SμM) designed for high-throughput electric-property screening as well as for rapid construction of electronic phase diagrams at low temperatures. As a sensor probe, we used a high-Qλ/4 coaxial cavity resonator to which a thin needle with ball-tip end was attached. The sensor module was mounted on the low-temperature XYZ stage, which allowed us to map out the change of resonance frequency and quality factor due to the local tip-sample interaction at low temperatures. From the measurements of combinatorial thin films, such as Ti1−xCoxO2−δ and Nd0.9Ca0.1Ba2Cu3O7−δ (NCBCO), it was demonstrated that this SμM system has enough performance for the high-throughput characterization of sample conductance under variable temperature conditions. 相似文献
10.