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排序方式: 共有118条查询结果,搜索用时 31 毫秒
1.
Munetaka Iwamura Airi Fukui Koichi Nozaki Hikaru Kuramochi Satoshi Takeuchi Tahei Tahara 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23354-23361
Femtosecond time-resolved absorption and picosecond time-resolved emission measurements were carried out for highly concentrated aqueous solutions of K2[Pt(CN)4] to investigate excited-state dynamics of the [Pt(CN)42−] oligomers formed with metallophilic interactions. Time-resolved absorption spectra exhibit complicated dynamics that are represented with five time constants. Among them, the 90-ps and 400-ps dynamics were assigned to the S1 → T1 intersystem crossing of the trimer and tetramer coexisting in the solution by comparison with the fluorescence decays. Clear oscillations of transient absorption were observed in the first few picoseconds, and the frequency-detected-wavelength 2D analysis revealed that the 135-cm−1 and 65-cm−1 oscillations arise from the Pt–Pt stretch motions of the S1 trimer and S1 tetramer, respectively. The obtained time-resolved spectroscopic data provide a clear view of the excited-state dynamics of the [Pt(CN)42−] oligomers in the femto-/picosecond time region. 相似文献
2.
3.
Tatsunori Iwamura Takashi Ichikawa Hiroshi Shimizu Tadashi Kataoka 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):471-472
Abstract Reactions of thiazolo[3,2-b]-1,2,4-triazolium N-methylides with electron-deficient acetylenes gave the thiazole ring-opened products as a mixture of the E-and Z-isomers. In contrast, the N-phenacylides reacted with dimethyl acetylenedicarboxylate to give the thiobenzoates together with the thiazole ring-opened products. The mechanism for formation of these compounds is described. 相似文献
4.
Summary A high-performance gel-permeation chromatographic (GPC) method is described for the determination of serum haptoglobin (Hp),
based on the estimation of the haptoglobin-hemoglobin (Hp−Hb) complex. Hemoglobin (Hb) is added to the serum and the resulting
Hp−Hb complex is separated by GPC and detected at 415 nm. The Hp−Hb complex separated chromatographically from serum migrated
electrophoretically with the globulin fraction. It was found to be stable over a period of one week at 4°C. The total analysis
time for a serum sample is approximately 20 min. The minimum detection limit is 30mg/L. Relative standard deviation values
were below 1% (peak area). No interferences from bilirubin or from turbidity of samples were observed. The results of the
GPC analysis correlate well with those obtained by nephelometric assay (r=0.996). 相似文献
5.
Yuuki Hirayama Kentaro Yamaguchi Shigeru Sakamoto Michiko Iwamura 《Tetrahedron letters》2005,46(6):1027-1030
A new AB2 type building block for synthesis of dendritic compounds is made starting from Michael addition of 2 equiv of 3-hydroxyacetophenone to acrylate, followed by decarboxylation and deprotection of either carboxyl or hydroxyl protecting groups. [G1]-[G4] dendrons and [G2] dendrimer were synthesized by the reiterative [hydrogenolysis then DCC/DPTS coupling] sequence using a combination of convergent and divergent growth methods. 相似文献
6.
Mitsuo Takayama Michiko Iwamura Shohaku Fuchibe 《Journal of mass spectrometry : JMS》1994,29(11):601-606
The formation of molecular ions, M+., under fast atom bombardment (FAB) conditions using a liquid matrix was examined by using a new type of synthesized compounds in which preferential M+. peaks appear in their FAB spectra. The FAB spectra were compared with the corresponding mass spectra obtained by the electron impact (EI) ionization, chemical ionization (CI) and charge-exchange ionization (CEI) methods. All of the spectra showed preferential peaks of M+. ion and a characteristic intense fragment ion peak originating from a β-fission. The FAB spectra were similar in the fragment ions appearing in the EI spectra and were very similar in the fragmentation pattern to the CEI spectra using Ar+. and Xe+. as the reagent ions. Further, the FAB spectra did not show any doubly charged ion peaks, while the 70 eV EI spectra showed the peaks of doubly charged molecular and/or fragment ions. The isobutane CI spectra of the synthesized compounds suggested that the formation of M+. ions occurred through the CE reaction with isobutane ion, C4H10+., and the CI spectra showed a marked intense fragment ion peak originating from the β-fission which seemed to occur characteristically in CEI processes. The results obtained suggested that the formation of M+. ions under matrix FAB conditions occurred mainly by CE reactions between the analytes M and matrix molecular ions B+. and/or fragment ions b+.. 相似文献
7.
Summary A high-performance liquid gel-permeation chromatographic method is described for the determination of human serum immunoglobulin G (IgG) by separating the fluorescent immuno complex from the free fluorescence-labeled antibody. Fluorescence-labeled antibody used in this study was fluorescein isothiocyanate (FITC)-labeled Fab fragment goat anti-human IgG (anti-IgG Fab). Immuno complexes and antibody of different molecular sizes can be separated. FITC-labeled anti-IgG Fab was added to the serum and the mixture is passed through the column. An immuno complex separates as well-delineated peak in the column void volume, and was measured by the fluorescence of the column eluate (Ex=490nm, Em=520nm). The total analysis time for a serum sample was approximately 15min. The minimum detection limit was 25 mg/dl. The relative standard deviation was below 2% (peak area). The results of the HPL-GPC analysis correlate well with those obtained by laser nephelometric assay (r=0.992). 相似文献
8.
Hiizu Iwamura Tadashi Sugawara Yuzo Kawada Kazuo Tori Ryonosuke Muneyuki Ryoji Noyori 《Tetrahedron letters》1979,20(36):3449-3452
Natural-abundance 17O NMR spectra have been measured for twenty one oxiranes. Their chemical shifts covering a 100 ppm range were interpreted in terms of the paramagnetic β- and diamagnetic γ-effects. In addition, through-space orbital interaction between the ethylenic π and the Walsh orbitals of the oxirane ring was suggested by a lowfield shift in norbornadiene -oxide. 相似文献
9.
10Gbit/s time-spread/wavelength-hop optical code generation and decoding are performed by dispersion-compensating fiber Bragg grating (FBG) en/decoder pair. Error-free 10km single mode fiber (SMF) transmission of 10Gbit/s optical code division multiplexing (OCDM) has been experimentally demonstrated. 相似文献
10.
This paper attempts to model capital budgeting problems by chance constrained integer programming in a fuzzy environment (rather than a stochastic environment). Some examples are also provided to illustrate the potential applications of new models. Finally, a fuzzy simulation based genetic algorithm is designed for solving chance constrained integer programming models with fuzzy parameters. 相似文献