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91.
Kunihiko Takabe Suguru Ohkawa Toshio Sato Gia Hien Tang Takao Katagiri 《Tetrahedron letters》1980,21(40):3883-3884
Dimerization of 3-methyl-3-butenenitrile (1) by lithium dialkylamide gave selectively 3,5,5-trimethyl-1-amino-4-cyanocyclohexa-1,3-diene (2), which was easily hydrolyzed by aqueous acid to afford 4-cyanoisophorone (3,5,5-trimethyl-4-cyano-cyclohex-2-enone) (3) quantitatively. 相似文献
92.
93.
An infrared, pulsed heterodyne laser radar using differential absorption technique with tunable lasers is proposed as a practical means of measuring dispersed air pollutants with range resolution. A system analysis shows that this scheme offers an adequate sensitivity for ranges up to several km. 相似文献
94.
Okada S Okinaka K Iwawaki H Furugori M Hashimoto M Mukaide T Kamatani J Igawa S Tsuboyama A Takiguchi T Ueno K 《Dalton transactions (Cambridge, England : 2003)》2005,(9):1583-1590
This study reports substituent effects of iridium complexes with 1-phenylisoquinoline ligands. The emission spectra and phosphorescence quantum yields of the complexes differ from that of tris(1-phenylisoquinolinato-C2,N)iridium(iii)(Irpiq) depending on the substituents. The maximum emission peak, quantum yield and lifetime of those complexes ranged from 598-635 nm, 0.17-0.32 and 1.07-2.34 micros, respectively. This indicates the nature of the substituents has a significant influence on the kinetics of the excited-state decay. The substituents attached to phenyl ring have an influence on a stability of the HOMO. Furthermore, those substituents have effect on the contribution to a mixing between 3pi-pi* and (3)MLCT for the lowest excited states. Some of the complexes display the larger quantum yield than Irpiq, which has the quantum yield of 0.22. The organic light emitting diode (OLED) device based on tris [1-(4-fluoro-5-methylphenyl)isoquinolinato-C2,N]iridium(iii)(Ir4F5Mpiq) yielded high external quantum efficiency of 15.5% and a power efficiency of 12.4 lm W(-1) at a luminance of 218 cd m(-2). An emission color of the device was close to an NTSC specification with CIE chromaticity characteristics of (0.66, 0.34). 相似文献
95.
Fuji T Rauschenberger J Apolonski A Yakovlev VS Tempea G Udem T Gohle C Hänsch TW Lehnert W Scherer M Krausz F 《Optics letters》2005,30(3):332-334
A new scheme for stabilizing the carrier-envelope (CE) phase of a few-cycle laser pulse train is demonstrated. Self-phase modulation and difference-frequency generation in a single periodically poled lithium niobate crystal that transmits the main laser beam allows CE phase locking directly in the usable output. The monolithic scheme obviates the need for splitting off a fraction of the laser output for CE phase control, coupling into microstructured fiber, and separation and recombination of spectral components. As a consequence, the output yields 6-fs, 800-nm pulses with an unprecedented degree of short- and long-term reproducibility of the electric field waveform. 相似文献
96.
Tsuboyama A Takiguchi T Okada S Osawa M Hoshino M Ueno K 《Dalton transactions (Cambridge, England : 2003)》2004,(8):1115-1116
The synthesis, structure, and photophysical properties of a new cyclometalated dinuclear iridium complex, (ppy)2Ir(mu-BPB)Ir(ppy)2 [ppy = 2-phenylpyridine, BPB = 1,4-bis(pyridin-2-yl)benzene], have been investigated. 相似文献
97.
Kobayashi T Kawai H Suzuki T Kawanishi T Hayakawa T 《Rapid communications in mass spectrometry : RCM》2004,18(10):1156-1160
This report describes an enhancement of the signal intensities of proteins and peptides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). When alpha-cyano-4-hydroxycinnamic acid (CHCA) premixed with human transferrin (Tf) was used as a matrix, the signal intensity of insulin was amplified to more than ten times that of the respective control in CHCA without Tf. The detection limit of insulin was 0.39 fmol on-probe in the presence of Tf, while it was 6.3 fmol in the absence of Tf. The signal intensity of insulin was also enhanced when the CHCA matrix was premixed with proteins other than Tf (80 kDa), such as horse ferritin (20 kDa), bovine serum albumin (BSA, 66 kDa), or human immunoglobulin G (150 kDa). The optimum spectrum of insulin was obtained when the added amount of protein was in the range 0.26-0.62 pmol, regardless of the molecular weight of the added protein. Tf and BSA outperformed the other tested proteins, as determined by improvements in the resulting spectra. When the mass spectra of several peptides and proteins were recorded in the presence of Tf or BSA, the signal intensities of large peptides such as glucagon were enhanced, though those of smaller peptides were not enhanced. In addition, the signal enhancement achieved with Tf and BSA was more pronounced for the proteins, including cytochrome C, than for the large peptides. This enhancement effect could be applied to improve the sensitivity of MALDI-TOFMS to large peptides and proteins. 相似文献
98.
The selective N-methylation of bifunctionalized amines with supercritical methanol (scCH(3)OH) promoted by the conventional solid acids (H-mordenite, beta-zeolite, amorphous silica-alumina) and acid-base bifunctional catalysts (Cs-P-Si mixed oxide and gamma-alumina) was investigated in a continuous-flow, fixed-bed reactor. The use of scCH(3)OH in the reaction of 2-aminoethanol with methanol (amine/CH(3)OH = 1/10.8) over the solid catalysts led to a significant improvement in the chemoselectivity of the N-methylation. Among the catalysts examined, the Cs-P-Si mixed oxide provided the most efficient catalyst performance in terms of selectivity and reactivity at 300 degrees C and 8.2 MPa; the N-methylation selectivity in the products reaching up to 94% at 86% conversion. The present selective methylation was successfully applied to the synthesis of N-methylated amino alcohols and diamines as well as O-methylated ethylene glycol. Noticeably, ethoxyethylamine was less reactive, suggesting that the hydroxy group of the amino alcohols is a crucial structural factor in determining high reactivity and selectivity, possibly because of the tethering effect of another terminus, a hydroxo group, to the catalyst surface. The magic-angle-spinning NMR spectroscopy and X-ray diffraction analysis of the Cs-P-Si mixed oxide catalyst revealed that the acidic and basic sites originate from P(2)O(5)/SiO(2) and Cs/SiO(2), respectively, and the weak acid-base paired sites are attributed to three kinds of cesium phosphates on SiO(2). The weak acid-base sites on the catalyst surface might be responsible for the selective dehydrative methylation. 相似文献
99.
Takao Akahori 《Journal of Mathematical Analysis and Applications》2004,300(1):43-53
Let (M,0T″) be a compact strongly pseudo convex CR structure with dimRM=2n−1. Then, in [Michigan Math. J. 50 (2002) 517-549], the construction of the versal family of CR structures is settled. The purpose of this paper is to introduce a canonical Kaehler metric for the parameter space of this versal family if the CR structure admits a normal vector field and a non-vanishing CR n-form with the condition and
100.
Takao Komatsu 《Journal of Number Theory》2004,109(1):27-40
We show some new variations on Tasoev's continued fractions , where the periodic parts include the exponentials in k instead of the polynomials in k. We also mention some relations with other kinds of continued fractions, in particular, with Rogers-Ramanujan continued fractions. 相似文献