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排序方式: 共有356条查询结果,搜索用时 78 毫秒
321.
Hiroko Watando Shioko Saya Taro Fukaya Shinetsu Fujieda Masaaki Yamamoto 《Polymer Degradation and Stability》2006,91(12):3354-3359
Flexible polyurethane foam was decomposed into a polyol mixture by an extruder with diethanolamine (DEA) as a decomposing agent. The resulting decomposed product could be used as an alternative virgin polyol in reclaiming polyurethane. In the case of reclaiming elastomer by using the decomposed product without any purification, virgin polyol could be alternated by the decomposed product up to 80%. It is a great improvement compared with the reclamation to foam, whose percentage was maximum 5%. Furthermore, the percentage could be improved up to 100% by purifying the decomposed product. We have found that physical properties of reclaimed polyurethane elastomer, such as tensile strength, hardness, and elongation, can be regulated by the ratio of unrefined/refined polyol. Whereas the tensile strength and the hardness increased as the content increased, the elongation decreased. 相似文献
322.
Matsuura K Yamashita T Igami Y Kimizuka N 《Chemical communications (Cambridge, England)》2003,(3):376-377
DNA three-way junctions formed from three 30-mer oligonucleotides that contain single-chained self-complementary sticky ends spontaneously self-assemble into 'nucleo-nanocages': the exo- and endo-nuclease digestion experiments indicate that defects such as the single and double strand end structures are absent on the spherical nano-assemblies, providing clear evidence for the closed nanocage structure. 相似文献
323.
Masao Kato Taro Ichijo Keizo Ishii Masaki Hasegawa 《Journal of polymer science. Part A, Polymer chemistry》1971,9(8):2109-2128
A new preparative route to photocrosslinkable polymers in which the polymers are produced directly from the polymerization of vinyl monomers having photocrosslinkable groups has been investigated. The photosensitive resins thus produced have higher sensitivity and resolution than conventional photosensitive resins. The monomers were synthesized from the esterification of vinylphenols or vinyl β-chloroethyl ether with cinnamic acid, β-styrylacrylic acid, and their homologs, and from the etherification of vinyl β-chloroethyl ether with hydroxychalcones. Homopolymerizations of these monomers and their copolymerizations with other comonomers were investigated with the use of both radical and ionic initiators. It is shown that radical polymerization of the monomers gave soluble polymers only at low conversion. Anionic initiators did not initiate polymerization. Cationic polymerization imparted soluble polymers in high yield, except for the monomers bearing cyano groups, which generally gave insoluble polymers. Infrared and NMR spectroscopic investigation of the cationically obtained soluble polymers and comparative investigation by cationic polymerization of model compounds indicated that polymerization of the monomers proceeds through the vinyl double bond without affecting the photosensitive unsaturated bond. Thus, linear photocrosslinkable polymers with an intact photoreactive group may be produced by cationic polymerization. In general, these polymers have uniform structure and modifiable physical properties depending on the monomer used. The polymer thus obtained from β-vinyloxyethyl cinnamate has been shown to have excellent properties for use as a photo-resist. 相似文献
324.
Mitsuo Takayama Toshio Fukai Taro Nomura Tatsuo Yamauchi 《Journal of mass spectrometry : JMS》1991,26(7):655-659
Positive-ion fast atom bombardment (FAB) mass spectra of flavonol and steroid glycosides with sodium chloride added showed well known characteristic features; of the appearance of [M + Na]+ peaks, disappearance of [M + H]+ peaks and a significant decrease in the peak heights of fragment ions. Compared with the features in the FAB mass spectra of crown ethers with addition of salt, and above features suggest a complexation between Na+ and the glycosides in matrix solution. The B/E-constant linked scanning technique was used to obtain structural information of the [M + Na]+ ion of the glycosides. The B/E spectra gave the daughter-ion peaks, suggesting that coordination of Na+ with the biosides and triosides occurs at the sugar moiety, whereas the coordination with the monoglycosides occurs at the aglycone moiety, except for monoglycosides in which the aglycone moiety does not contain significant oxygen functional groups such as OH and CO. 相似文献
325.
Tsubomura T Enoto S Endo S Tamane T Matsumoto K Tsukuda T 《Inorganic chemistry》2005,44(18):6373-6378
Cu(I)-Cu(I) and Cu(I)-Ru(II) dinuclear complexes bridged by the 2,5-bppz (2,5-bis(2-pyridyl)pyrazine) ligand have been prepared and characterized including the X-ray crystallographic study of the dinuclear [{CuI(PPh3)2}2(mu-2,5-bppz)](PF6)2)2CH3Cl complex: a = 13.974(2), b = 13.993(2), c = 13.537(2) A; alpha = 101.98(1), beta = 103.22(1), gamma = 113.90(1) degrees ; triclinic, P, Z = 1. The trinuclear [{(bpy)2RuII(mu-2,5-bppz)}2CuI](PF6)5 complex was also prepared, and the structure of the complex in solution was studied by spectrometric titration. The dinuclear Cu(I) complex and [(bpy)2RuII(mu-2,5-bppz)CuI(PPh3)2](PF6)5 show photoluminescence in the solid state, which should arise from MLCT states. Photochemical oxidation of the trinuclear RuII2CuI complex occurs in the presence of oxygen to give a RuII2CuII complex. The MLCT states and the redox reaction in the excited state are discussed. 相似文献
326.
Masao Kato Hiroshi Urabe Yoshinao Oosawa Taro Saito Yukiyoshi Sasaki 《Journal of organometallic chemistry》1976,121(1):81-91
Cationic palladium(II) and platinum(II) complexes with chelate ylides and neutral ligands of the type, [MCl (Y) (L)]+BPh4? (M Pd or Pt; Y bdep or bdmp*; L = 4-methylpyridine, 3,5-dimethylpyrazole, PPh3, PCy3, PMePh2, P(OMe)3, AsPh3 or SbPh3) and [M(bdep) (4-methylpyridine)2] (BPh4)2 (M = Pd or Pt) were prepared and characterized by means of infrared and 1H NMR spectra. 相似文献
327.
A nucleophilic N-heterocyclic carbene has been successfully used in a Pd(0)-catalyzed allylic substitution for the first time. It was found that allylic substitution with a soft nucleophile using a Pd-carbene catalyst proceeds via retention of configuration, the stereochemical reaction pathway being the same as that of the reaction using a Pd-phosphine complex. [reaction--see text] 相似文献
328.
329.
Taro Ueda Takayuki Nagano Hajime Okawa Seiji Takahashi 《Electrochemistry communications》2009,11(8):1654-1656
An amperometric zirconia-based sensor attached with perovskite-type oxide sensing electrode was examined for monitoring NO2 in automobile exhaust. The sensor using La0.6Sr0.4Co0.98Mn0.02O3 showed high response to NO2. The response was almost linear to NO2 concentration in the range between 50 and 800 ppm, and a 90% reaction time to 400 ppm NO2 was less than 20 s. Though the NO2 response of the sensor was slightly affected by the changes in O2 concentrations, it showed still high response in the examined range of 5–21 vol%. 相似文献
330.
Atsushi Yamaguchi Naoya Nakagawa Taro Sekikawa Hiroyuki Asanuma 《Applied Surface Science》2009,255(24):9864-9868
We performed the transient absorption measurement and the first rate equation (RE) analysis for cis isomer of 4-carboxy-2′,6′-dimethylazobenzene to clarify the quantitative difference between the photoisomerization process and the thermal relaxation process from the excited state. The RE analysis enabled us to determine the cis-to-trans photoisomerization rate per each pump pulse to be 3% under the condition of the 430 nm, 150 fs pump pulse with energy of 200 nJ. Moreover, the signal due to the yielded trans molecules appearing in the transient absorption was assigned from the following observed result: the transient absorbance change at the 380 nm probe mostly decreased within 300 fs after the 430 nm pulse pumping and then slowly decreased to zero, while the absorbance change at the 350 nm probe had a positive constant component in the over one picosecond time region. The RE analysis showed that this constant component is due to the yielded trans molecules, and its positive value is due to the fact that the absorption cross-section of the -to- transition in their trans molecules is larger than that of the -to- transition in the original cis molecules. 相似文献