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61.
Won E Ko BR Adachi I Aihara H Arinstein K Asner DM Aushev T Bakich AM Barberio E Bay A Bhardwaj V Bhuyan B Bischofberger M Bondar A Bozek A Bračko M Brodzicka J Browder TE Chang P Chen A Chen P Cheon BG Chilikin K Cho IS Cho K Choi SK Choi Y Dalseno J Danilov M Doležal Z Drásal Z Drutskoy A Eidelman S Fast JE Gaur V Gabyshev N Garmash A Goh YM Golob B Haba J Hara T Hayasaka K Hayashii H Horii Y Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Inami K Ishikawa A Itoh R Iwabuchi M Iwasaki Y Iwashita T 《Physical review letters》2011,107(22):221801
We report the first observation of the doubly Cabibbo-suppressed decays D(+)→K(+)η((')) using a 791 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The ratio of the branching fractions of doubly Cabibbo-suppressed relative to singly Cabibbo-suppressed D(+)→π(+)η((')) decays are B(D(+)→K(+)η)/B(D(+)→π(+)η)=(3.06±0.43±0.14)% and B(D(+)→K(+)η')/B(D(+)→π(+)η')=(3.77±0.39±0.10)%. From these, we find that the relative final-state phase difference between the tree and annihilation amplitudes in D(+) decays, δ(TA), is (72±9)° or (288±9)°. We also report the most precise measurements of CP asymmetries to date: A(CP)(D(+)→π(+)η)=(+1.74±1.13±0.19)% and A(CP)(D(+)→π(+)η')=(-0.12±1.12±0.17)%. 相似文献
62.
Pinki Gaur 《合成通讯》2013,43(17):2270-2279
AbstractHerein, we report an efficient synthesis of N-nitrosamines from cyclic, aliphatic, benzylic, and aromatic secondary amines via a novel straightforward, efficient, and mild chemical process using sodium nitrite and Oxone in methanol as a solvent at 0–5?°C. The demonstrated methodology accounts well for the parameters like cost-effective, short reaction time, clean and safe handling along with good to excellent yields. 相似文献
63.
64.
Aspy Mehta Umesh Gaur Bernhard Wunderlich 《Journal of Polymer Science.Polymer Physics》1978,16(2):289-296
The equilibrium melting temperature, volume, and enthalpy and entropy changes on melting of poly(ethylene terephthalate) have been analyzed and heats of fusion have been newly measured with an automated scanning calorimeter to yield the following data: 553°K, 16.9 cm3/mole, 2.69 kJ/mole, and 48.6 J/deg/mole, respectively. A more detailed discussion of annealed samples obtained from etched starting materials shows that the density of the noncrystalline regions may be variable. 相似文献
65.
The object of the present investigation is to study the anisotropic propagation of weak discontinuities in flows of thermally conducting and dissociating gases. The velocity of propagation of the wave frcnt is determined. A set of differential equations governing the growth and decay of weak discontinuities are obtained and solved. It is found that if the sonic wave is a compressive wave of order 1, then it terminates into a shock wave after a critical timet c which has been determined. It is also observed that the effects of heat conduction and dissociation are to decrease the duration of time by which a weak discontinuity will generate into a shock wave. 相似文献
66.
Truong TT Lin R Jeon S Lee HH Maria J Gaur A Hua F Meinel I Rogers JA 《Langmuir : the ACS journal of surfaces and colloids》2007,23(5):2898-2905
This paper describes composite patterning elements that use a commercially available acryloxy perfluoropolyether (a-PFPE) in various soft lithographic techniques, including microcontact printing, nanotransfer printing, phase-shift optical lithography, proximity field nanopatterning, molecular scale soft nanoimprinting, and solvent assisted micromolding. The a-PFPE material, which is similar to a methacryloxy PFPE (PFPE-DMA) reported recently, offers a combination of high modulus (10.5 MPa), low surface energy (18.5 mNm(-1)), chemical inertness, and resistance to solvent induced swelling that make it useful for producing high fidelity patterns with these soft lithographic methods. The results are comparable to, and in some cases even better than, those obtained with the more widely explored material, high modulus poly(dimethylsiloxane) (h-PDMS). 相似文献
67.
Koo CK Wang S Gaur RL Samain F Banaei N Kool ET 《Chemical communications (Cambridge, England)》2011,47(41):11435-11437
Polyfluorophores built on a DNA scaffold (ODFs) were synthesized and tested for fluorescence responses to the volatiles from M. tuberculosis, E. coli and P. putida in closed Petri dishes. Two sensors in a pattern-based response could distinguish the bacterial strains accurately, suggesting the use of ODFs in rapid identification of infectious agents. 相似文献
68.
Background
Dihydrolinalool and terpineol are sources of fragrances that provide a unique volatile terpenoid alcohol of low toxicity and thus are widely used in the perfumery industry, in folk medicine, and in aromatherapy. They are important chemical constituents of the essential oil of many plants. Previous studies have concerned the biotransformation of limonene by Pseudomonas putida. The objective of this research was to study biotransformation of myrcene by Pseudomonas aeruginosa. The culture preparation was done using such variables as different microbial methods and incubation periods to obtain maximum cells of P. aeruginosa for myrcene biotransformation.Results
It was found that myrcene was converted to dihydrolinalool and 2,6-dimethyloctane in high percentages. The biotransformation products were identified by Fourier-transform infrared spectroscopy (FT-IR), ultraviolet (UV) analysis, gas chromatography (GC), and gas chromatography-mass spectroscopy (GC-MS). Comparison of the different incubation times showed that 3 days was more effective, the major products being 2,6-dimethyloctane (90.0%) and α-terpineol (7.7%) and comprising 97.7%. In contrast, the main compounds derived for an incubation time of 1.5 days were dihydrolinalool (79.5%) and 2,6-dimethyloctane (9.3%), with a total yield of 88.8%. 相似文献69.
Gaur S Miller JT Stellwagen D Sanampudi A Kumar CS Spivey JJ 《Physical chemistry chemical physics : PCCP》2012,14(5):1627-1634
Nearly monodispersed Au(38)(SC(12)H(25))(24) clusters (1.7 ± 0.2 nm) were synthesized using a modified Brust process while utilizing a "thiol etching" approach for the ligand exchange. HRTEM, MALDI, FTIR, and XAS analysis confirmed the formation of the 38-atom clusters in solution. This solution was used to impregnate a microporous TiO(2) support to give 0.7% Au(38)/TiO(2) catalyst. Subsequent drying in air and treatment with H(2)/He at 400 °C removed most of the sulfur ligands, and also increased the Au cluster size to 3.9 ± 0.96 nm. XPS and EXAFS analysis of this supported catalyst showed trace levels of residual sulfides, apparently located at the Au-TiO(2) interface. CO oxidation tests on these supported clusters show an activation energy and range of TOFs comparable to those reported by others. These results suggest that supported Au clusters of controllable size can be prepared with this thiol-ligated solution-based method, providing a new approach to the synthesis of these catalysts. 相似文献
70.
Satyendra N. Shukla Pratiksha Gaur Mamta Prasad Mahender Prasad Ripul Mehrotra Sheela Mathews 《中国化学会会志》2012,59(4):485-493
The reaction of a new heterocyclic bidentate N containing spacer, (ligand) 5,5′‐methylenebis(pyridine) with ruthenium sulphoxide precursors resulted, dinuclear complexes. We herein report three formulations; [{cis,fac‐RuCl2(so)3}2(μ‐mbp)].3so; [{trans,mer‐RuCl2(so)32}2(μ‐mbp)].3so and [{trans‐RuCl4(so)}2(μ‐mbp)]2?[X]2+; where so = dimethyl‐sulfoxide/tetramethylenesulfoxide; mbp = 5,5′‐methylenebis(pyridine) and [X]+ = [(dmso)2H]+, Na+ or [(tmso)H]+. These complexes were characterized on the basis of elemental analyses, molar conductance measurement, magnetic susceptibility, FT‐IR, 1H‐NMR, 13C{1H}‐NMR, electronic spectroscopy and FAB‐Mass spectrometry. Catalytic activity of these complexes has been investigated in hydrolysis of benzonitrile. All the complexes exhibit good antibacterial activity against gram‐negative bacteria Escherichia coli in comparison to Chloramphenicol. 相似文献