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1.
Gunawan Gunawan Tito Viswanathan Shawn Bourdo Alexandru S. Biris 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):768-777
Abstract A novel, fast, and easy method for synthesizing a carbon-supported Ni2P nanocomposite (C/Ni2P) is described. The process involves a reaction between a nickel salt, phosphoric acid, and a carbon source by utilizing microwave irradiation. The carbon source for the nanocomposite is from renewable supplies, namely, tannin and lignin. The method has successfully synthesized Ni2P nanoparticles dispersed in a carbon matrix with a particle size ranging from 20 to 50 nm in diameter. During the microwave process, tannin and lignin provided a reducing environment in the microwave irradiation process. The synthesized products are characterized by several characterization methods. The method showed that phosphoric acid, which is a nontoxic compound, could be used as an alternative P source for synthesizing Ni2P. The method is fast, easy, and an economical process to synthesize the carbon-coated Ni2P nanocomposite. 相似文献
2.
JPC – Journal of Planar Chromatography – Modern TLC - A simple and rapid TLC-densitometric method has been developed for simultaneously determination of hydrocortisone acetate and... 相似文献
3.
Enhancement of Solar Hydrogen Evolution from Water by Surface Modification with CdS and TiO2 on Porous CuInS2 Photocathodes Prepared by an Electrodeposition–Sulfurization Method 下载免费PDF全文
Dr. Jiao Zhao Dr. Tsutomu Minegishi Li Zhang Dr. Miao Zhong Gunawan Dr. Mamiko Nakabayashi Dr. Guijun Ma Dr. Takashi Hisatomi Dr. Masao Katayama Prof. Dr. Shigeru Ikeda Prof. Dr. Naoya Shibata Prof. Dr. Taro Yamada Prof. Dr. Kazunari Domen 《Angewandte Chemie (International ed. in English)》2014,53(44):11808-11812
Porous films of p‐type CuInS2, prepared by sulfurization of electrodeposited metals, are surface‐modified with thin layers of CdS and TiO2. This specific porous electrode evolved H2 from photoelectrochemical water reduction under simulated sunlight. Modification with thin n‐type CdS and TiO2 layers significantly increased the cathodic photocurrent and onset potential through the formation of a p–n junction on the surface. The modified photocathodes showed a relatively high efficiency and stable H2 production under the present reaction conditions. 相似文献
4.
Dienone—phenol rearrangement in (CD3CO)2O/BF3 of 1-acetoxy cyclohexadienones derived from benzene yields mainly monoacetoxy monotrideuteroacetoxy derivatives of benzene. The implications of these results on the reaction mechanism are discussed. 相似文献
5.
We report the observation of commensurability oscillations in an AlAs two-dimensional electron system where two conduction-band valleys with elliptical in-plane Fermi contours are occupied. The Fourier power spectrum of the oscillations shows two frequency components consistent with those expected for the Fermi contours of the two valleys. From an analysis of the spectra we deduce m(l)/m(t)=5.2+/-0.5 for the ratio of the longitudinal and transverse electron effective masses, a fundamental parameter that cannot be directly measured from other transport experiments. 相似文献
6.
Multistage Interconnection Networks (MINs) are network systems providing fast and efficient communications at a reasonable cost. A gamma network is a specific class of MINs, which provides redundant paths in the system. In a gamma network, information from source nodes is transmitted through a specific set of routes to destination nodes. Reliability of an MIN is used as a measure of system’s ability to transform information from input to output devices. Due to the complexity of network configuration and availability of redundant paths, reliability bounds to estimate the exact reliability of a gamma network is proposed. A numerical example of an 8 × 8 gamma network is presented to demonstrate the accuracy of the reliability bounds. When the lower bound reliability provides sufficient assurance that the system will be operational at some specified time and closely approximates the exact reliability, then no further effort for obtaining the exact reliability expression is necessary. 相似文献
7.
Ming J. Lau Ming W. Lau Christa Gunawan Bruce E. Dale 《Applied biochemistry and biotechnology》2010,162(7):1847-1857
Empty palm fruit bunch fiber (EPFBF), a readily available cellulosic biomass from palm processing facilities, is investigated
as a potential carbohydrate source for cellulosic ethanol production. This feedstock was pretreated using ammonia fiber expansion
(AFEX) and enzymatically hydrolyzed. The best tested AFEX conditions were at 135 °C, 45 min retention time, water to dry biomass
loading of 1:1 (weight ratio), and ammonia to dry biomass loading of 1:1 (weight ratio). The particle size of the pretreated
biomass was reduced post-AFEX. The optimized enzyme formulation consists of Accellerase (84 μL/g biomass), Multifect Xylanase
(31 μL/g biomass), and Multifect Pectinase (24 μL/g biomass). This mixture achieved close to 90% of the total maximum yield
within 72 h of enzymatic hydrolysis. Fermentation on the water extract of this biomass affirms that nutrients solely from
the pretreated EPFBF can support yeast growth for complete glucose fermentation. These results suggest that AFEX-treated EPFBF
can be used for cellulosic biofuels production because biomass recalcitrance has been overcome without reducing the fermentability
of the pretreated materials. 相似文献
8.
The following article describes a concise synthesis of a collection of 4,5-dihydro-1H-benzo[e][1,4]diazepines fused to a hydantoin ring. Molecular complexity and biological relevance are high and structures are generated in a mere three steps, employing the Ugi reaction to assemble diversity reagents. The protocol represents a novel UDC (Ugi-deprotect-cyclize) strategy employed in the Ugi-5-component CO2-mediated condensation, followed by further cyclization under basic conditions, to afford the fused hydantoin. Mechanistic caveats, dependent on the aldehydes of choice will be revealed and a facile oxidation of the final products to imidazolidenetriones is briefly discussed. 相似文献
9.
Liu S Yu Z Yu X Huang SX Luo Y Wu L Shen W Yang Z Wang L Gunawan AM Chan RJ Shen B Zhang ZY 《Chemistry & biology》2011,18(1):101-110
SHP2 phosphatase is a positive transducer of growth factor and cytokine signaling. SHP2 is also a bona fide oncogene; gain-of-function SHP2 mutations leading to increased phosphatase activity cause Noonan syndrome, as well as multiple forms of leukemia and solid tumors. We report that tautomycetin (TTN), an immunosuppressor in organ transplantation, and its engineered analog TTN D-1 are potent SHP2 inhibitors. TTN and TTN D-1 block T?cell receptor-mediated tyrosine phosphorylation and ERK activation and gain-of-function mutant SHP2-induced hematopoietic progenitor hyperproliferation and monocytic differentiation. Crystal structure of the SHP2?TTN D-1 complex reveals that TTN D-1 occupies the SHP2 active site in a manner similar to that of a peptide substrate. Collectively, the data support the notion that SHP2 is a cellular target for TTN and provide a potential mechanism for the immunosuppressive activity of TTN. Moreover, the structure furnishes molecular insights upon which therapeutics targeting SHP2 can be developed on the basis of the TTN scaffold. 相似文献
10.
Gunawan O Shkolnikov YP Vakili K Gokmen T De Poortere EP Shayegan M 《Physical review letters》2006,97(18):186404
We report direct measurements of the valley susceptibility, the change of valley population in response to an applied symmetry-breaking strain, in an AlAs two-dimensional electron system. As the two-dimensional density is reduced, the valley susceptibility dramatically increases relative to its band value, reflecting the system's strong electron-electron interaction. The increase has a remarkable resemblance to the enhancement of the spin susceptibility and establishes the analogy between the spin and valley degrees of freedom. 相似文献