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151.
Nishibayashi Y Yoshikawa M Inada Y Hidai M Uemura S 《The Journal of organic chemistry》2004,69(10):3408-3412
Thiolate-bridged diruthenium complexes such as [Cp*RuCl(mu(2)-SR)(2)RuCp*Cl] (Cp* = eta(5)-C(5)Me(5); R = Me, (n)Pr, (i)Pr) and [Cp*RuCl(mu(2)-S(i)Pr)(2)RuCp*(OH(2))]OTf (OTf = OSO(2)CF(3)) promote the cycloaddition between propargylic alcohols and cyclic 1,3-dicarbonyl compounds to give either the corresponding 4,6,7,8-tetrahydrochromen-5-ones or 4H-cyclopenta[b]pyran-5-ones in high yields with complete regioselectivity. This catalytic cycloaddition provides a simple and one-pot synthetic protocol for a variety of substituted chromenones and cyclopenta[b]pyranones. 相似文献
152.
Titanium tetraiodide promotes an aza-Reformatsky-type reaction of alpha-iodomethyl ketone O-alkyl oximes with carbonyl compounds to give beta-hydroxy ketone O-alkyl oximes in good to high yields. 相似文献
153.
A. Toyoda K. Ishida K. Shimomura Y. Matsuda W. Higemoto S. N. Nakamura T. Matsuzaki K. Nagamine 《Hyperfine Interactions》2001,132(1-4):307-312
Recently, the applicability of Penning trap mass spectrometry has been extended to nuclides with a half-life of less than
one second. The mass of 33Ar (T
1/2=174 ms) was measured using the ISOLTRAP spectrometer with an accuracy of 4.2 keV. This measurement provided a stringent test
of the Isobaric Multiplet Mass Equation (IMME) at mass number A=33 and isospin T=3/2. The fast measurement cycle that shows the way to other measurements of very-short-lived nuclides is presented. Furthermore,
the results of the IMME test are displayed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
154.
Soil-blade dynamics in reverse-rotational rotary tillage 总被引:3,自引:0,他引:3
Soil cutting and the clod crack formation process during reverse-rotational rotary tillage in a heavy clay soil were investigated. Of particular interest was the relationship between clod crack formation and tillage resistance during sequential rotations of the tillage blade. Investigation of the crack formation process is helpful to develop and to design more effective and high performance tillage methods. This paper describes two new discoveries. The first is that the tillage resistance showed a higher cross-correlation between sequential rotations within a certain distance of tilling, while there was little or no cross-correlation between different tillage plots that were separated more than 0.4 m. The forward distance of untilled soil that was disturbed by the tillage blade was estimated to be 36.4 mm. This is the distance of two tillage pitches. The second discovery involved the blade frequencies during tilling. Fluctuation in tillage resistance frequencies of a single blade was nearly equal to the predicted occurrence of crack intervals on the tilled clod's surface. This frequency was 120 Hz. When these frequencies were translated into the distance along the trochoid trajectory of the blade cutting edge, they were the same as the length of the clods tilled by the reverse-rotational rotary tiller. These minute vibrations in the tillage resistance were considered the important indexes for recognizing the tilled soil conditions and the tilled clod failure on the reverse-rotational rotary tiller. The analytical results of this paper will be utilized for the active occurrence of the cracks regarding with natural frequency of the blade and the operation condition of the reverse-rotational rotary tiller. 相似文献
155.
Vinyloxydichloroboranes (1) are scarcely found in literature2 probably because of certain unstable properties. We have found that some vinyloxyamino-chloroboranes (2), which can be prepared by formal substitution of one chlorine atom of 1 with a diethylamino group, are isolable stable compounds. 相似文献
156.
Shigeo Hayakawa Shinya Matsumoto Mami Hashimoto Kenichi Iwamoto Hirofumi Nagao Michisato Toyoda Yasushi Shigeri Michiko Tajiri Yoshinao Wada 《Journal of the American Society for Mass Spectrometry》2010,21(9):1482-1489
Post-translational modifications (PTMs) of proteins are important in the activation, localization, and regulation of protein
function in vivo. The usefulness of electron capture dissociation (ECD) and electron-transfer dissociation (ETD) in tandem
mass spectrometry (MS/MS) using low-energy (LE) trap type mass spectrometer is associated with no loss of a labile PTM group
regarding peptide and protein sequencing. The experimental results of high-energy (HE) collision induced dissociation (CID)
using the Xe and Cs targets and LE-ETD were compared for doubly-phosphorylated peptides TGFLT(p)EY(p)VATR (1). Although HE-CID using the Xe target did not provide information on the amino acid sequence, HE-CID using the Cs target
provided all the z-type ions without loss of the phosphate groups as a result of HE-ETD process, while LE-ETD using fluoranthene
anion gave only z-type ions from z5 to z11. The difference in the results of HE-CID between the Xe and Cs targets demonstrated that HE-ETD process with the Cs target
took place much more dominantly than collisional activation. The difference between HE-ETD using Cs targets and LE-ETD using
the anion demonstrated that mass discrimination was much weaker in the high-energy process. HE-ETD was also applied to three
other phosphopeptides YGGMHRQEX(p)VDC (2: X = S, 3: X = T, 4: X = Y). The HE-CID spectra of the doubly-protonated phosphopeptides
(= [M + 2H]2+) of 2, 3, and 4 using the Cs target showed a very similar feature that the c-type ions from c7 to c11 and the z-type ions from z7 to z11 were formed via N-Cα bond cleavage without a loss of the phosphate group. 相似文献
157.
Itsuo Mori Takako Matsuo Yoshikazu Fujita Minako Toyoda Kenichi Ichitani Noriko Inoue 《Fresenius' Journal of Analytical Chemistry》1994,348(5-6):346-349
Summary A spectrofluorophotometric determination of thallium(III) is proposed. It is based on the enhancement of the fluorescence reaction of 3,4,5,6-tetrachlorofluorescein (TCF) with Pyrogallol Red (PR) by thallium(III) in the presence of Swanol (AM 301, lauryldimethyl aminoacetic acid betain) as an amphoteric surfactant. The method was found to be suitable for the determination of thallium(III) down to 4.0 g in 10.0 ml by measuring the difference in the relative fluorescence intensities of a TCF/PR/thallium(III) solution and a TCF/PR solution. The recovery test in artificial urine was satisfactory (96±2%). 相似文献
158.
Vanadium oxyacetylacetonate [VO(acac)(2)] works as a catalyst for the direct synthesis of 3-sulfanylindoles from indoles and thiols under an atmospheric pressure of molecular oxygen as a reoxidant. For example, the reaction of 2-phenylindole with benzenethiol in the presence of a catalytic amount of VO(acac)(2), potassium iodide, and 2,6-di-tert-butyl-p-cresol in chlorobenzene under molecular oxygen proceeds to afford 2-phenyl-3-(phenylsulfanyl)indole in 86% yield. This catalytic system can also be applied to 2-naphthols instead of indoles to give the corresponding 1-sulfanyl-2-naphthols in up to 57% yield. 相似文献
159.
160.
T. Sekine T. Nakashizu K. Toyoda K. Uchinokura E. Matsuura 《Solid State Communications》1980,35(4):371-373
Raman scattering of layer-type compound 2H-WS2 has been studied at room temperature. The first-order Raman peaks are observed at 27.4, 357 and 423 cm-1. The low-frequency peak at 27.4 cm-1 is a rigid-layer mode, from which the interlayer shear force constant is estimated. The central force model is applied to the high-frequency phonons. The interlayer shear force constant is much smaller than the intralayer force constants. We also find several peaks due to the second-order processes. 相似文献