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  • The Langmuir-Blodgett (L-B) technique was employed to fabricate the monolayers and bilayers of nano-sized beta (nano-beta) crystals, and the monolayers of micrometer-sized beta (micro-beta) crystals on various substrates including glass plate, α-Al2O3 disk, glass capillary tube, copper wire, stainless-steel tube and γ-Al2O3 tube. With respect to the methanol suspension of 1 wt.% Nano-beta modified with cetyltrimethylammonium bromide (CTAB), a two-region surface pressure-area isotherm was obtained, leading to the formation of both Nano-beta monolayers and bilayers with satisfactory degree of coverage (DOC) and close packing (DCP) under each transfer surface pressure. When nano-beta crystals were dealuminated, the surface pressure-area relation was reduced to the one-region isotherm, and the resulting L-B film contained aggregated areas. As for the assembly of micro-beta crystals, both methanol and sec-butanol were used as the dispersant. The resulting micro-beta monolayer was randomly oriented with the sedimentation of large truncated-square-bipyramid crystals on compression by using the methanol suspension. The use of sec-butanol as the dispersant resulted in the enhanced hydrophobicity of micro-beta crystals due to the chemical reaction of sec-butanol molecules with surface silanols, leading to the formation of c-oriented micro-beta monolayers over various substrates, and simultaneously the sedimentation of large truncated-square-bipyramid crystals did not occur. Under the structure direction of the c-oriented micro-beta monolayer in the seeded growth, the dense and preferentially c-oriented zeolite beta film could be fabricated, which could not be formed on either the Nano-beta monolayer or the micro-beta monolayer with random orientation. Therefore, it would be concluded that the growth of beta crystals over the seed layer could be followed by the epitaxial growth mechanism.
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  • A promising mesoporous SiAl material, Al-MCM-41 was successfully prepared by alkali calcination leaching of natural palygorskite, and sequent hydrothermal synthesis coupled with calcination. The morphology, structure, surface area and pore-size distribution of the material were characterized by scanning electron microscopy, small-angle X-ray diffraction and N2 adsorption–desorption isotherms. The Al-MCM-41 possessed better crystallinity and larger specific surface area with CTAB/SiO2 mass ratio of 0.1:1, pH of 5, crystallization temperature of 110 °C, crystallization time of 12 h and calcination of 550 °C for 5 h. The Al-MCM-41 was used as an adsorbent for the removal of hazardous aniline dye-basic fuchsin from water. Adsorption kinetics and isotherms analysis indicated that adsorption of basic fuchsin onto Al-MCM-41 followed pseudo-first-order model and Langmuir adsorption isotherm. In addition, intra-particle diffusion was rate determining step of the adsorption process. The results demonstrated that the as-synthesized Al-MCM-41 had potential applications in the treatment of waste water.
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  • To investigate Holocene vegetation and fire-disturbance histories in the treeline ecotone, macroscopic charcoal, plant-macrofossil, and pollen records from two lacustrine sediment records were used. Lake Lia is on the southern slope and Lake Brazi is on the northern slope of the west-east-oriented Retezat Mountain range in the Romanian Carpathians. The records were used to reconstruct Holocene fire-return intervals (FRIs) and biomass burning changes. Biomass burning was highest at both study sites during the drier and warmer early Holocene, suggesting that climate largely controlled fire occurrence. Fuel load also influenced the fire regime as shown by the rapid biomass-burning changes in relation to timberline shifts. Overall, the number of inferred fire episodes was smaller on the northern than on the southern slope. FRIs were also comparatively longer (1000–4000 years) on the northern slope where Picea abies-dominated woodlands persisted around Lake Brazi throughout the Holocene. On the southern slope, where Pinus mugo was more abundant around Lake Lia, FRIs were significantly shorter (80–1650 years). A period of frequent fire episodes occurred around 1900–1300 cal yr BP on the southern slope, when chironomid-inferred summer temperatures increased and the pollen record documents increased anthropogenic activity near the treeline. However, the forest clearance by burning to increase grazing land was subdued in comparison to other European regions.
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  • This paper describes the optimization and comparison of conventional and microwave-assisted methods for efficient, cheap, one-pot, and straightforward synthesis of isocoumarins under mild reaction conditions. On this basis of this aim, synthesis of 3-acetyl isocoumarin from 2-formylbenzoic acid with mono-chloroacetone was chosen as a model reaction. Afterward, four different methods conventional (Method A), microwave open vessel (Method B), microwave sealed vessel (Method C), and microwave closed system (Method D) were used methodologically to determine best experimental conditions for each of these methods in this model reaction. The results revealed that developed Methods A, C and D could be used successfully under solvent-free conditions with good yields (84–87%) for the future efficient, one-pot synthesis of isocoumarins. This paper is also a first for characterizing 3-acetyl isocoumarin by using ATR, 1H NMR, 13C NMR and GC–MS.
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  • The air pollutant fly ash was facile designed as a green catalyst and practical to organic synthesis. We have designed sulfated Bi2O3-fly ash catalyst (12wt%) and it was characterized by Fourier transform infrared (FT-IR), confocal Raman, Powder X-ray diffraction (XRD), Field emission electron microscopy (FE-SEM), elemental color mapping, energy-dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) techniques. The sulfated Bi2O3-fly ash was found an excellent catalytic application for the synthesis of (6H-pyrido[3,2-b]carbazol-4-yl)aniline derivatives in water has been described. The synthesized (6H-pyrido[3,2-b]carbazol-4-yl)aniline derivatives were confirmed by spectral techniques Fourier transform infrared (FT-IR), Nuclear magnetic resonance (NMR) and Liquid chromatography–mass spectrometry (LC–MS). The significant catalytic role of Bi–N interaction was readily form adduct, moreover Bi–O bond was favorable for hydrogen abstraction, dehydration and aromatization. Due to the strong potential, the precise reaction time and high yield have been achieved, which is realized from hot filtration test. The sulfated Bi2O3-fly ash catalyst could be reused for five successive run, the resulting in no appreciable change in the catalytic activity. The crystal phase and surface morphology of fifth run catalyst were examined by powder XRD, FE-SEM, EDS and TEM techniques, and the results revealed no changes in catalyst nature. The sulfated Bi2O3-fly ash catalyst has high efficiency, reusability, good catalytic activity, environmentally harmless and notable potential in industrial applications.
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  • The majority of archaeological remains found at El Castillo in northern Iberia were excavated between 1910 and 1914 by Hugo Obermaier. Since the 1980s El Castillo has been studied through a detailed analysis of Obermaier's original excavation notes, the cleaning and study of the extant section, and the excavation of material in the shelter entrance. Radiocarbon dating of charcoal from the modern (1980s onwards) excavation suggested that unit 18, corresponding to Aurignacian Delta of the 1910s excavation, was significantly earlier than other Aurignacian assemblages in western Europe. Combined with a reanalysis of the lithic and osseous industry, these dates led to the suggestion that material in unit 18 and Aurignacian Delta was a transitional industry, showing a gradual transformation of the Mousterian into the Upper Palaeolithic. The conclusion has profound implications for understanding the appearance of the Upper Palaeolithic in western Europe. However, the theory has been heavily debated, with criticism focusing on the analysis of the lithic and bone assemblage as well as the chronology. We focus on the latter, and assess whether the original dates were accurate, whether they were well associated with the archaeology, and whether there was vertical and lateral variation in the age of the assemblages within unit 18 and Aurignacian Delta. New radiocarbon dates on humanly modified bone suggest that in the new area of excavation, unit 18 is found to be earlier than 42 cal kBP, with no evidence of material of a younger age. In contrast, in the old excavation area, Aurignacian Delta does include material of a younger age. This suggests that discussion of the Transitional Aurignacian can only include material from unit 18, in the new area of excavation.
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  • Glacial lake outburst floods (GLOFs) have recently become one of the primary natural hazards in the Himalayas. There is therefore an urgent need to assess GLOF hazards in the region. Cirenmaco, a moraine-dammed lake located in the upstream portion of Zhangzangbo valley, Central Himalayas, has received public attention after its damaging 1981 outburst flood. Here, by combining remote sensing methods, bathymetric survey and 2D hydraulic modeling, we assessed the hazard posed by Cirenmaco in its current status. Inter-annual variation of Cirenmaco lake area indicates a rapid lake expansion from 0.10±0.08km2 in 1988 to 0.39±0.04km2 in 2013. Bathymetric survey shows the maximum water depth of the lake in 2012 was 115±2m and the lake volume was calculated to be 1.8×107m3. Field geomorphic analysis shows that Cirenmaco glacial lake is prone to GLOFs as mass movements and ice and snow avalanches can impact the lake and the melting of the dead ice in the moraine can lower the dam level. HEC-RAS 2D model was then used to simulate moraine dam failure of the Cirenmaco and assess GLOF impacts downstream. Reconstruction of Cirenmaco 1981 GLOF shows that HEC-RAS can produce reasonable flood extent and water depth, thus demonstrate its ability to effectively model complex GLOFs. GLOF modeling results presented can be used as a basis for the implementation of disaster prevention and mitigation measures. As a case study, this work shows how we can integrate different methods to GLOF hazard assessment.
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  • Intracellular α-amylase was a special glycoside hydrolase in the cytoplasm. We cloned and expressed an intracellular α-amylase, Amy, from Paenibacillus sp. SSG-1. The recombinant enzyme was purified by metal-affinity chromatography, exhibited a molecular mass of 71.7 kDa. Amy exhibited unexpectedly sequence similarity and evolutionary relationships with alpha-glucanotransferase. The docked results of Amy with maltose showed it had similar catalytic residues with α-amylase and glucanotransferase. The substrate specificity experiment showed that Amy could hydrolyze typical substrates into glucose and maltose. It was noteworthy that Amy showed the catalytic capacity of cyclomaltodextrinase and pullulanase. Meanwhile, Amy could transfer sugar molecules and form maltotetraose upon the hydrolysis of substrates. These results indicated that Amy was a novel intracellular α-amylase with distinct catalytic ability characteristics of hydrolyzing glycogen/cyclodextrin/pullulan and transglycosylation. We deduced that Amy may play an important role in utilizing maltooligosaccharides that released from extracellular α-glucan or storage α-glucan (glycogen) in Paenibacillus sp. SSG-1.
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  • In this study, a novel fluorescein-derived Schiff-base ligand bearing a chromone moiety which was called 6-Hydroxy-3-formylchromone fluorescein hydrazone (1) has been designed, synthesized and evaluated as a Mg2+ “turn on” fluorescent probe. This probe 1 exhibited high selectivity and sensitivity towards Mg2+ over other important metal ions investigated, and the remarkable enhancement in fluorescence emission centered at 504nm was observed in the presence of Mg2+, which was attributed to the ring-opening process of the fluorescein fluorophore in probe 1 upon complexation of 1 with Mg2+. Furthermore, the “turn on” response of this probe 1 to Mg2+ was nearly completed within 3min, which indicated that this probe 1 could be utilized to sense and monitor Mg2+ for real-time detection.
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  • Detailed study of the period before schizophrenic relapse when early warning signs (EWS) are present is crucial to effective pre-emptive strategies.
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