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991.
Meir Israelowitz Jeong-Ah Kwon Syed W. H. Rizvi Christoph Gille Herb P. von Schroeder 《Canadian Metallurgical Quarterly》2011,8(2)
The Melanophila acuminata beetle is attracted to forest fires via a pair of infrared sensory organs composed of sensilla. Our histological work showed that each sensillum contains lipid layers surrounding a protein layer and a unique polysaccharide base that is associated with a neuron to each sensillum. Infrared microscopy showed that the protein region maximally absorbs infrared radiation at 3 μm wavelength and at 10 μm, which corresponds to the known radiation produced by forest fires at 3 μm.Mathematical calculations showed that the physical properties of the sensilla are such that the expected temperature rise is insufficient for transduction of the infrared signal through mechanical means or as a thermal receptor as previously thought;hence the protein plays the pivotal role in perception of single photons and transmission of the signal within the sensilla. 相似文献
992.
993.
Huai T Durbin ST Younglove T Scora G Barth M Norbeck JM 《Environmental science & technology》2005,39(24):9595-9600
NH3 emissions from motor vehicles have been the subject of a number of recent studies due to their potential impact on ambient particulate matter (PM). Highly time-resolved NH3 emissions can be measured and correlated with specific driving events utilizing a tunable diode laser (TDL). It is possible to incorporate NH3 emissions with this new information into models that can be used to predict emissions inventories from vehicles. The newer generation of modal models are based on modal events, with the data collected at second-by-second time resolution, unlike the bag-based emission inventory models such as EMFAC and MOBILE. The development of an NH3 modal model is described in this paper. This represents one of the first attempts to incorporate vehicle NH3 emissions into a comprehensive emissions model. This model was used in conjunction with on-road driving profiles to estimate the emissions of SULEV, ULEV, and LEV vehicles to be 9.4 +/- 4.1, 21.8 +/- 5.2, and 34.9 +/- 6.0 mg/mi, respectively. We also implement this new NH3 model to predict and evaluate the NH3 emission inventory in the South Coast air basin (SoCAB). 相似文献
994.
Im Jin A Kim Min Seo Kwon Oran shin Jae-Ho Kim Ji Yeon 《Food science and biotechnology》2021,30(9):1249-1256
Food Science and Biotechnology - This study evaluated the anti-inflammatory effect of ginger-cinnamon mixture using an animal model of dextran sulfate sodium (DSS)-induced intestinal inflammation.... 相似文献
995.
The reaction of hexavalent chromium (Cr(VI)) with zerovalent iron (Fe0) during soil and groundwater remediation is an important environmental process. This study used several techniques including X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy to investigate nanometer scale Fe0 particles (nano Fe0) treated with Cr(III) and Cr(VI). X-ray diffraction and XPS analyses of oxidized nano Fe0 showed the crystalline Fe(III) phase is composed of lepidocrocite (gamma-FeOOH). Results of XPS Cr 2p data and Cr K-edge X-ray absorption near edge spectroscopy (XANES) provided evidence that Cr(VI) was entirely reduced to Cr(III) by nano Fe0 with no residual Cr(VI) after reaction. In addition, XPS and XANES results of Cr(III) precipitated as Cr(OH)3 in the presence of corroding nano Fe0 were nearly identical to the Cr(VI)-nano Fe0 reaction product. Detailed analysis of XPS O 1s line spectra revealed that both Cr(III)- and Cr(VI)-treated nano Fe0 yielded a predominantly hydroxylated Cr(OH)3 and/ or a mixed phase CrxFe(1 - x)(OH)3 product. The structure of the Cr(III)- and Cr(VI)-treated nano Fe0 determined using extended X-ray absorption fine structure spectroscopy (EXAFS) revealed octahedral Cr(III) with Cr-O interatomic distances between 1.97 and 1.98 A for both Cr(III) and Cr(VI) treatments and a pronounced Cr-Cr second interatomic shell at 3.01 A. Our results suggest that the reaction product of Cr(VI)-treated nano Fe0 is either a poorly ordered Cr(OH)3 precipitate or possibly a mixed phase CrxFe(1 - x)(OH)3 product, both of which are highly insoluble under environmental conditions. 相似文献
996.
The combination of micro and nanostructured hydroxyapatite (HAp) was isolated from Thunnus obesus bone via thermal calcination method in the presence of polymers such as poly ethylene glycol (PEG), poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) (PEG-PPG-PEG) and poly vinyl alcohol (PVA). The thermal stability, crystalline phase, chemical composition and morphology of the derived HAp were characterized by thermal gravimetric analysis, X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy analysis. The physicochemical characteristic examination revealed that derived HAp was coherent with standard HAp data. Moreover, FE-SEM depicted significant difference in the crystal size of HAp derived with thermal calcination, with and without added polymers. The crystallinity of HAp isolated in the presence of polymer was lower than that obtained in the absence of polymers. The biocompatibility of the derived HAp crystals was checked with MC3T3-E1 osteoblastic cells by MTT assay and Hoechst-33342 staining. The biocompatibility of HAp derived by polymer assisted thermal calcination method revealed that it is less toxic as compared to HAp derived in the absence of polymer. As an inference, polymer assisted thermal calcination derived HAp is good in terms of the presence of combined micro and nanostructured HAp and its low toxicity will bring about new orthopaedic applications. 相似文献
997.
998.
An HS Kim BH Lee JW Dong CM Kim SK Kim YC 《International journal of molecular sciences》2011,12(9):6024-6039
Pen shell (Atrina pectinata) is a popular food source with a high commercial value in a number of Asian Pacific areas. The natural A. pectinata population has been declining continuously over the past several decades. Microsatellite DNA markers are a useful DNA-based tool for monitoring the genetic variation of pen shell populations. In this study, 20 polymorphic microsatellite (MS) DNA markers were identified from a partial genomic pen shell DNA library enriched in CA repeats, and used to compare allelic variation between wild and hatchery pen shell populations in Korea. A total of 438 alleles were detected at the 20 MS loci in the two populations. All loci were easily amplified and demonstrated allelic variability, with the number of alleles ranging from 5 to 35 in the wild population and from 5 to 22 in the farmed population. The average observed and expected heterozygosities were 0.69 and 0.82, respectively, in the hatchery samples and 0.69 and 0.83, respectively, in the wild samples. Statistical analysis of fixation index (F(ST)) and analysis of molecular variance (AMOVA) showed minor, but significant, genetic differences between the wild and hatchery populations (F(ST) = 0.0106, CI(95%) = 0.003-0.017). These microsatellite loci may be valuable for future aquaculture and population genetic studies for developing conservation and management plans. Further studies with additional pen shell samples are needed to conclusively determine the genetic diversity between the wild and hatchery populations. 相似文献
999.
Sunhyung Kim Jonghee Han Yongchai Kwon Kug-Seung Lee Tae-Hoon Lim Suk Woo Nam Jong Hyun Jang 《Electrochimica acta》2011,(23):7984
Using platinum (Pt) black and carbon-supported Pt (Pt/C) as cathode catalysts, membrane-electrode assemblies (MEAs) were fabricated with various Nafion ionomer content, and their direct formic acid fuel cell (DFAFC) performances were investigated. In MEAs incorporating Pt black catalysts, the current density at 0.6 V was highest at ionomer/catalyst volume ratio of 1.0, which was consistent with the electrochemical active area (EAS) variation measured by cyclic voltammetry. However, the current density measured at 0.3 V, the cell performance increased with Nafion ionomer content, especially at low ionomer loading, indicating that proton transport rate played an important role. The variation in ionic resistance (Rion) of cathode layers with Nafion ionomer content was experimentally confirmed by using the complex capacitance analysis of impedance data implemented with nitrogen (cathodes)/hydrogen (anodes) atmosphere. For Pt/C, the layer thickness and EAS of cathode were larger than those of MEA cathode using Pt black; and the current densities at 0.6 V were lower than those of Pt black, suggesting that smaller fraction of EAS was utilized. 相似文献
1000.
DoHwan Nam RyoungHee Kim DongWook Han JeongHan Kim HyukSang Kwon 《Electrochimica acta》2011,(25):9397
Copper foam with dendritic copper nanostructure was synthesized by an electrodeposition process using hydrogen bubbles as dynamic templates. To modify the morphology of the copper nanostructure in the foam walls, (NH4)2SO4 and BTA (benzotriazole) were introduced into the electrolytic bath as chemical additives, and their influences on the morphologies and the structural characteristics of copper deposits were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical strength and stiffness of the copper foam were evaluated by the compression test. The corncob-like deposits of the copper foam were changed to needle-like nanodendrites by the addition of (NH4)2SO4, which significantly improved the mechanical strength and stiffness due to the self-supporting effects of the tightly interlocked needle-like nanodendrites. In contrast, the copper foam prepared from the solution with (NH4)2SO4 and BTA shows high ductility but low mechanical strength due to the formation to grape-like copper deposits. Both the copper foams exhibited higher mechanical properties than the one with corncob-like deposits formed in the additive-free solution. The reaction mechanism of (NH4)2SO4 and BTA on the nanostructure of the copper foam at high cathodic current density was clarified by analyzing the effects of the additives on the copper deposition reaction and hydrogen gas evolution reaction, respectively. 相似文献