| 31. |
- Ma, Ming-Guo, et al.
(författare)
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Isolation and characterization of hemicelluloses extracted by hydrothermal pretreatment
- 2012
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 114, s. 677-683
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Tidskriftsartikel (refereegranskat)abstract
- The dewaxed sample from Triploid of Populus tomentosa Carr. was extracted by using organic alkaline solvent (Dimethylformamide, DMF) via hydrothermal pretreatment. Neutral sugar compositions and molecular weight analysis demonstrated that the hemicellulosic fractions with a higher Uro/Xyl ratio, namely the more branched hemicelluloses, had higher molecular weights. Interestingly, these results were different from the previous report, in which the ratio of Uro/Xyl in the water-soluble hemicellulosic fraction was more than that of the alkali-soluble hemicellulosic fraction. Spectroscopy (FUR, H-1 NMR, C-13 NMR, and HSQC) analysis indicated that the hemicellulosic fractions were mainly composed of (1 -> 4)-linked alpha-D-glucan from starch and (1 -> 4)-linked beta-D-xylan attached with minor amounts of branched sugars from hemicelluloses. In addition, thermal analysis implied that linear hemicelluloses showed more thermal stability than the branched ones during pyrolysis.
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| 32. |
- Ma, Ming-Guo, et al.
(författare)
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Nanocomposites of cellulose/iron oxide : influence of synthesis conditions on their morphological behavior and thermal stability
- 2012
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Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems. - : Elsevier BV. - 0928-4931 .- 1873-0191. ; 32:6, s. 1511-1517
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposites of cellulose/iron oxide have been successfully prepared by hydrothermal method using cellulose solution and Fe(NO3)(3)center dot 9H(2)O at 180 degrees C. The cellulose solution was obtained by the dissolution of microcrystalline cellulose in NaOH/urea aqueous solution, which is a good system to dissolve cellulose and favors the synthesis of iron oxide without needing any template or other reagents. The phases, microstructure, and morphologies of nanocomposites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectra (EDS). The effects of the heating time, heating temperature, cellulose concentration, and ferric nitrate concentration on the morphological behavior of products were investigated. The experimental results indicated that the cellulose concentration played an important role in both the phase and shape of iron oxide in nanocomposites. Moreover, the nanocomposites synthesized by using different cellulose concentrations displayed different thermal stabilities.
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| 33. |
- Ma, Ming-Guo, et al.
(författare)
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Rapid microwave-assisted synthesis and characterization of cellulose-hydroxyapatite nanocomposites in N,N-dimethylacetamide solvent
- 2010
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Ingår i: Carbohydrate Research. - : Elsevier BV. - 0008-6215 .- 1873-426X. ; 345:8, s. 1046-1050
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Tidskriftsartikel (refereegranskat)abstract
- Preparation of nanocomposites was carried out using microcrystalline cellulose, CaCl2, and NaH2PO4 in N,N-dimethylacetamide (DMAc) solvent by a microwave-assisted method at 150 degrees C. XRD results showed that the nanocomposites consisted of cellulose and hydroxyapatite (HA). The cellulose existed as a matrix in the nanocomposites. SEM and TEM analysis showed that HA nanorods were homogeneously dispersed in the cellulose matrix. The effects of the microwave heating time on the products were investigated This method has advantages of being simple, rapid, low-cost, and environmentally friendly. (C) 2010 Elsevier Ltd. All rights reserved
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| 34. |
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| 35. |
- Schoch, Conrad L., et al.
(författare)
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Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
- 2014
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Ingår i: Database: The Journal of Biological Databases and Curation. - : Oxford University Press (OUP). - 1758-0463. ; 2014:bau061, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.
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| 36. |
- Shi, Yantao, et al.
(författare)
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A green route and rational design for ZnO-based high-efficiency photovoltaics
- 2014
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 6:10, s. 5093-5098
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Tidskriftsartikel (refereegranskat)abstract
- In this work, at room-temperature and without any organic surfactants we reported two green and facile approaches for rapid synthesis of ZnO nanorods (NRs) and nanosheet-based ZnO hierarchical structures (NSHSs). Based on their structural advantages, the quasi-solid ZnO-DSCs achieved a record photoelectric conversion efficiency (PCE) of 6.83%.
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| 37. |
- Shi, Yantao, et al.
(författare)
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Solid-State Synthesis of ZnO Nanostructures for Quasi-Solid Dye-Sensitized Solar Cells with High Efficiencies up to 6.46%
- 2013
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 25:32, s. 4413-4419
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Tidskriftsartikel (refereegranskat)abstract
- Solid-state synthesis of ZnO nanostructured building blocks is presented in this work for the fabrication of high efficiency quasi-solid dye-sensitized solar cells (DSSCs). The sponge-like photoanode has high optical density and better connections. Baking the photoanode at low temperature, photoconversion efficiencies of up to 6.46% are yielded by the quasi-solid DSSCs. Furthermore, we demonstrate better stability of our ZnO quasi-solid DSSCs.
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| 38. |
- Shi, Yantao, et al.
(författare)
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Ultrarapid Sonochemical Synthesis of ZnO Hierarchical Structures : From Fundamental Research to High Efficiencies up to 6.42% for Quasi-Solid Dye-Sensitized Solar Cells
- 2013
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 25:6, s. 1000-1012
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Tidskriftsartikel (refereegranskat)abstract
- Zinc oxide (ZnO) hierarchical structures (HSs) have recently demonstrated notable photochemical and photovoltaic performances attributed to their nano/micro combined architectures. In this study, ZnO HSs were synthesized at room temperature using ultrarapid sonochemistry. This novel approach can effectively overcome deficiencies in the synthesis via traditional direct precipitation by promoting nucleation and accelerating diffusion. Only 15 min was needed to complete the formation of highly crystallized and uniformed HSs consisting of interconnected monocrystalline nanosheets using sonochemistry. The formation of HSs through in situ observations was interpreted using a new mechanism based on oriented attachment and reconstruction. In the nonequilibrium synthesis system, thicker, porous, and coarse crystallized ZnO sheets were first constructed via oriented attachment of small-sized nanocrystals. After reconstruction, untrathin, integrated, and monocrystalline nanosheets were obtained. According to the two-dimensional nanosheets to three-dimensional HSs, the formation was much more sophisticated because repeated and parallel heterogeneous oriented attachments with reconstructions dominated the final morphologies of the HSs. The relationships between synthetic conditions and HSs structures were established. Based on the photoanodes in dye-sensitized solar cells (DSCs), the performances of these differently structured HSs were tested. HSs with densely assembled nanosheets exhibited better performances in photoelectric conversions. Systematic investigations were also carried out by selecting two representative HSs to demonstrate the critical factors governing the optical and electrical properties of photoanodes. Finally, under AM 1.5 and 100mW cm(-2) light irradiation, high photoelectric conversion efficiencies of up to 6.42% were achieved. These results established a new record for quasi-solid ZnO-based DSCs.
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| 39. |
- Wosinski, Lech, et al.
(författare)
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Photonic crystals for polarization splitting, filtering and sensing
- 2010
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Ingår i: 2010 OSA-IEEE-COS Advances in Optoelectronics and Micro/Nano-Optics, AOM 2010. - : IEEE Communications Society. - 9781424483938 - 9781424483921
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Konferensbidrag (refereegranskat)abstract
- In this paper we discuss different unconventional nanophotonic solutions using photonic crystal-based components including filters, sensors and polarization splitter, which utilizes positive and negative refracted beams. We illustrate them with design, technology and fabricated devices.
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| 40. |
- Xu, Tao, et al.
(författare)
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Pillar-array based optical sensor
- 2010
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Ingår i: Optics Express. - 1094-4087. ; 18:6, s. 5420-5425
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Tidskriftsartikel (refereegranskat)abstract
- An optical microcavity based on pillar arrays has been fabricated in Si/SiO2 material system. Transmission measurement was taken and a quality factor as high as 27,600 was observed. This cavity was tested for sensing applications by immersing into optical fluids with accurate refractive indices. For refractive index change of 0.01, a resonance peak wavelength shift of 3.5 nm was measured. We also compare cavities consisting of pillars with different aspect ratios.
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