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11.
Identifying Different Types of Catalysts for CO2 Reduction by Ethane through Dry Reforming and Oxidative Dehydrogenation 下载免费PDF全文
Dr. Marc D. Porosoff Myat Noe Zin Myint Dr. Shyam Kattel Zhenhua Xie Elaine Gomez Dr. Ping Liu Prof. Dr. Jingguang G. Chen 《Angewandte Chemie (International ed. in English)》2015,54(51):15501-15505
The recent shale gas boom combined with the requirement to reduce atmospheric CO2 have created an opportunity for using both raw materials (shale gas and CO2) in a single process. Shale gas is primarily made up of methane, but ethane comprises about 10 % and reserves are underutilized. Two routes have been investigated by combining ethane decomposition with CO2 reduction to produce products of higher value. The first reaction is ethane dry reforming which produces synthesis gas (CO+H2). The second route is oxidative dehydrogenation which produces ethylene using CO2 as a soft oxidant. The results of this study indicate that the Pt/CeO2 catalyst shows promise for the production of synthesis gas, while Mo2C‐based materials preserve the C? C bond of ethane to produce ethylene. These findings are supported by density functional theory (DFT) calculations and X‐ray absorption near‐edge spectroscopy (XANES) characterization of the catalysts under in situ reaction conditions. 相似文献
12.
A. N. Ermakov B. S. Ishkhanov I. M. Kapitonov Kyaw Kyaw Htun I. V. Makarenko V. N. Orlin V. I. Shvedunov 《Physics of Atomic Nuclei》2008,71(3):397-404
An experiment in which the gold isotope 197Au was irradiated with a beam of bremsstrahlung photons having an endpoint energy of E γ m = 67.7 MeV and originating from the RTM-70 racetrack microtron of the Institute of Nuclear Physics at Moscow State University was performed. The gammaray spectra of the residual beta activity of an irradiated sample were measured. Multinucleon photonuclear reactions on 197Au nuclei were observed in the experiment. Photonuclear reactions on a 197Au nucleus that involve the emission of up to seven neutrons were recorded for the first time. The experimental results in question suggest the important role of the quasideuteron photodisintegration mechanism in the energy region behind the giant dipole resonance. 相似文献
13.
Brinda Balasubramanian Simran Venkatraman Kyaw Zwar Myint Sucheewin Krobthong Patompon Wongtrakoongate Jittiyawadee Sripa Panthip Rattanasinganchan Pornphimon Metheenukul Rutaiwan Tohtong 《Molecules (Basel, Switzerland)》2022,27(14)
Cholangiocarcinoma (CCA) is a heterogenous group of malignancies in the bile duct, which proliferates aggressively. CCA is highly prevalent in Northeastern Thailand wherein it is associated with liver fluke infection, or Opisthorchis viverrini (OV). Most patients are diagnosed in advanced stages, when the cancer has metastasized or severely progressed, thereby limiting treatment options. Several studies investigate the effect of traditional Thai medicinal plants that may be potential therapeutic options in combating CCA. Galangin is one such herbal flavonoid that has medicinal properties and exhibits anti-tumor properties in various cancers. In this study, we investigate the role of Galangin in inhibiting cell proliferation, invasion, and migration in OV-infected CCA cell lines. We discovered that Galangin reduced cell viability and colony formation by inducing apoptosis in CCA cell lines in a dose-dependent manner. Further, Galangin also effectively inhibited invasion and migration in OV-infected CCA cells by reduction of MMP2 and MMP9 enzymatic activity. Additionally, using proteomics, we identified proteins affected post-treatment with Galangin. Enrichment analysis revealed that several kinase pathways were affected by Galangin, and the signature corroborated with that of small molecule kinase inhibitors. Hence, we identified putative targets of Galangin using an in silico approach which highlighted c-Met as candidate target. Galangin effectively inhibited c-Met phosphorylation and subsequent signaling in in vitro CCA cells. In addition, Galangin was able to inhibit HGF, a mediator of c-Met signaling, by suppressing HGF-stimulated invasion, as well as migration and MMP9 activity. This shows that Galangin can be a useful anti-metastatic therapeutic strategy in a subtype of CCA patients. 相似文献
14.
Kyaw Myint T. Barfels J.-C. Kuhr H.-J. Fitting 《Analytical and bioanalytical chemistry》1998,361(6-7):637-639
A new approach is described for depth profiling in stratified multilayer samples by recording energy dependent characteristic x-ray EDX(E 0 ) curves in a scanning electron microscope. An effective layer technique replaces the x-ray excitation function of the heterogeneous target by an equivalent function of a homogeneous sample. First results of thickness determination are shown and compared to direct measurements of film thickness monitoring (FTM) and atomic force microscopy (AFM). 相似文献
15.
Yang Nan Wei Xu Kyaw Zaw Kathrine E. Hughes Liang-Fu Huang William J. Dunn Ludwig Bauer Hemendra N. Bhargava 《Journal of heterocyclic chemistry》1997,34(4):1195-1203
Fusion of an azole moiety at C-6 and C-7 of naltrexone ( 1 ) is illustrated by the synthesis of the title compound 8 . Bromination of 3-O-methylnaltrexone led to the 1,7α-dibromo derivative which reacted with thiourea to attach the 2-aminothiazole ring to C-6 and C-7 of naltrexone. After converting the amino and alcohol groups to trimethylsilyl derivatives, the aromatic bromo group was removed by halo-lithium interchange with butyllithium, followed by hydrolysis with water. In the final step of the synthesis, the methyl ether was cleaved by boron tribromide to generate 8 . An alternate synthesis of 8 commenced with 3-O-acetylnaltrexone ( 9 ). Bromination of 9 in acetic acid in the presence of hydrobromic acid produced a mixture of 3-O-acetyl-7α-bromonaltrexone ( 10 ) and 7α-bromonaltrexone ( 11 ), both, as hydrobromides. Reaction of this mixture with thiourea furnished 8 (62% from 1 ). While 1H and 13C chemical shifts of all compounds are reported, those of 11 hydrobromide and 8 dihydrochloride were established unequivocally. 相似文献
16.
The surface patterns formed during submonolayer Cu/Ni and Pt/Ni heteroepitaxy upon a Ni(100) substrate have been investigated by kinetic Monte Carlo (KMC) simulations. The two-dimensional (2D) KMC simulations are based upon rate constants for a complete nearest-neighbor set of 729 uncorrelated Cu or Pt atoms and/or Ni site-to-site hopping mobilities. The rate constant activation energies are determined by classical-potential total-energy calculations using an embedded-atom method potential function from the literature. We find that diffusion of Cu atoms occurs at a faster rate and Pt atoms at a slower rate than that of Ni atoms on the flat Ni(100) surface, and the initial nucleation and growth patterns of 2D islands and the kinetic versus thermodynamic control of the growth vary as a consequence. In the temperature and deposition time regime in which we work, the Cu/Ni systems show less than random mixing, while the Pt/Ni systems show more than random mixing. The Cu/Ni system has bonding energies that result in a tendency to segregate toward subdomains of pure Ni and Cu, though kinetic effects in the epitaxy trap the development of the system at small subdomain sizes. The Pt/Ni system has bonding energies giving a tendency to intermix completely, while epitaxial kinetic effects modestly interfere with the complete mixing. The kinetically determined island morphologies under various Cu/Ni and Pt/Ni compositions and deposition rates differ substantially over time periods that are long on the deposition time scale, and therefore the island patterns can become frozen in place. 相似文献
17.
Jae Jeong Lee Liang-Fu Huang Kyaw Zaw Ludwig Bauer 《Journal of heterocyclic chemistry》1998,35(1):81-89
Successful syntheses of 2,4-dichlorophenyl 2-(1-methyl-5-imidazolyl)ethyl and 2,4-dichlorophenyl 3-(1-methyl-5-imidazolyl)propyl ketones are described. In addition, syntheses of 2,4-dichlorophenyl and 4-chlorophenyl 3-(1-methyl-1H-5-tetrazolyl)propyl ketones are reported. 相似文献
18.
Kyaw Zaw Lin V. G. Syromyatnikov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2016,10(4):687-692
In this paper, a multilayer neutron monochromator-polarizer, consisting of 490 alternating layers of iron and niobium, is proposed. Each layer of iron or niobium has a thickness of 25 Å. The use of thin layers in the structure period improves the quality of the monochromator-polarizer and yields a neutron beam reflected from this structure with high wavelength resolution and a small fraction of minor nonmonochromatic contributions to the intensity of the reflected beam. The fact that the layer thicknesses are the same in the period suppresses even-order Bragg peaks. The parameters of the first-order Bragg peak for eight model neutron monochromators-polarizers based on iron and cobalt are given. It follows from the calculated curve of the coefficient of neutron reflection from the Fe/Nb structure that the first-order Bragg peak has a half width of 1.1%, a relative reflection coefficient of 0.997, and a maximum polarizing efficiency of unity. We also present the first experimental curves of the coefficient of neutron reflection from this structure, depending on the momentum transfer for both spin components of the beam. 相似文献
19.
Patterson EE Piyankarage SC Myasein KT Pulido JS Dundervill RF Hatfield RM Shippy SA 《Analytical and bioanalytical chemistry》2008,392(3):409-416
A low-volume automated injection system for the analysis of chemically complex, amino acid samples is presented. This system
utilizes submicroliter sample volumes stored on a 75-μm inner diameter capillary. A pulse of positive pressure (82 kPa) is
used to load nanoliter sample volumes into an in-house fabricated interface and onto a separation capillary. Residual sample
solution in the interface is immediately washed away by a continuous transverse flow through the injection interface, yielding
a sharp and reproducible sample plug. By performing multiple injections of a static sample, one may average the signals to
yield a signal-to-noise ratio improvement of up to 4.07-fold for 20 injections compared with a theoretical maximum of a 4.47-fold
improvement. Without interruption of the applied voltage, injections performed every 150 s were used to monitor the progress
of the reaction of multiple amino acids with the fluorogenic dye 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde. Analysis
of dialyzed clinical vitreous samples demonstrates the resolution and quantitation of arginine, lysine, leucine, glutamine,
and glutamate. Observed levels are comparable with those of nonautomated injection methods and reports by others.
Figure Multiple injections of fluorescently labeled human vitreous with a detailed view of a single injection (above) and with all injections
segmented and averaged for signal-to-noise ratio improvement (right) 相似文献
20.
Nattawit Dejdumrong Huynh Ngoc Phien Hoang le Tien Kyaw Moe Lay 《International Journal of Mathematical Education in Science & Technology》2013,44(4):565-584
A new transform proposed by Oyelami and Ale for impulsive systems is applied to an impulsive fish-hyacinth model. A biological policy regarding the growth of the fish and the hyacinth populations is formulated. 相似文献