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911.
Mingzhou Yu Antti Joonas Koivisto Kaarle Hämeri Martin Seipenbusch 《Aerosol science and technology》2013,47(4):427-434
A thorough understanding of the importance of aerosol coagulation and deposition relative to each other as modifiers of the particle size distribution plays an important role in the proper selection of conditions to estimate the deposition rate coefficient. In this work, a theoretical analysis was conducted for investigating the size-resolved ratio of coagulation to deposition for different types of size distributions using the Simpson integral method. The theoretical model was subsequently qualitatively validated by experiments in a completely mixed and ventilated aerosol chamber. Both experimental and theoretical studies show that the ratio of the rates of coagulation to deposition is strongly dependent on the total particle number concentration and the geometric mean diameter of the aerosol. A variation of the ratio of coagulation to deposition by several orders of magnitude for aerosols with differing size distributions was found. Thus the previously employed criterion for the negligence of coagulation based solely on the total particle number concentration was shown to be insufficient to accurately judge whether an aerosol is suited for the estimation of the deposition rate coefficient. Aerosols with wide size distributions are not recommended for use in the estimation of the deposition rate coefficient. The study provides a method to understand the role of coagulation and deposition for indoor aerosols. Copyright 2013 American Association for Aerosol Research 相似文献
912.
913.
Sunmi Shin Rudolf Schäfer Bruno C. De Cooman 《Metallurgical and Materials Transactions A》2013,44(9):4239-4247
Magnetic materials such as Fe-Si alloys are magnetized by the rearrangement of their magnetic microstructure and domain wall motion. Understanding magnetic microstructures in the interior of a ferromagnet is essential for the control and reduction of energy losses in electrical devices. The three-dimensional magnetic microstructure of solids is still unknown due to the lack of an appropriate observation technique, and the magnetic domain wall structure inside a ferromagnet has never been observed with sufficiently high resolution. The first observation of the 3D magnetic microstructure of an Fe-6.6 pct Si alloy with a high spatial resolution is reported. The domain walls known to exist inside positive anisotropy cubic materials, i.e., the 180-deg domain walls and the 90-deg domain walls, were analyzed for the first time. The structure and orientation of the domain walls were found to be very different from the prediction of current theoretic models. 相似文献
914.
Inclusions in commercial low and medium carbon ferromanganese 总被引:1,自引:0,他引:1
Thobias Sjöqvist Pär Jönsson Öystein Grong 《Metallurgical and Materials Transactions A》2001,32(5):1049-1056
The microstructures of commercial low and medium carbon ferromanganese have been studied by optical microscopy and electron
microprobe techniques. Element analysis and mapping have been performed on impurities in the matrix and nonmetallic inclusions
present. The results show that the most common nonmetallic inclusion is managanese oxide, followed by complex compounds of
managanese oxide, silicon oxide, and manganese sulfide. The different inclusions have been assessed according to the SS 111116
method. It follows that over 85 pct of the present nonmetallic inclusions are manganese oxides and that the amount of manganese
oxide inclusions is inversely proportional to the carbon content in standard refined ferromanganese. 相似文献
915.
Malle Mandre Henn Pärn Jaan Klõšeiko Morten Ingerslev Inge Stupak Margus Kört Keddy Paasrand 《Biomass & bioenergy》2010,34(9):1384-1392
Short-term effects of different doses (0.25; 0.5 and 1.0 kg m?2) of wood ash (WA), peat ash (PA) and their mixture (MA) applied to peat substrate on the mineral composition and growth of seedlings of Betula pendula were investigated. The experiments were conducted with 1-year-old seedlings planted in vegetation pots. The pH of the substrate was increased by 0.4–0.9 units during the vegetation period compared to the control. The peat substrate was poor in nutrients, except N. The substrate treated with WA had higher concentrations of K, Mg, Mn, Fe, P, Zn, Cr and Pb, but a lower N concentration compared to the control. The substrate treated with PA had higher concentrations of Ca, Mg, N and P. The concentrations in the MA treatment were intermediate between WA and PA. The ashes increased K and lowered the concentration of Ca. A decrease in N in seedlings was found under the influence of WA and MA. An increase in K and P was found in all compartments of seedlings, while the concentrations of Ca, Mg, Cu, Zn, Cd and Cr in seedlings were affected irregularly depending on types and doses of ashes used. The uptake of Cd, Cr and Pb did not reach phytotoxic levels; however, increased concentrations of Cd and Pb were found in roots. A positive influence of ash application on growth was found. The heights and root collar diameters of all ash-fertilised treatments exceeded those of the control seedlings in most cases. 相似文献
916.
Dr. Madina Mansurova Julian Simon Dr. Susanne Salzmann Prof. Dr. Christel M. Marian Prof. Dr. Wolfgang Gärtner 《Chembiochem : a European journal of chemical biology》2013,14(5):645-654
Two chemically synthesized flavin derivatives, 8‐trifluoromethyl‐ and 8‐bromoriboflavin (8‐CF3RF and 8‐BrRF), were photochemically characterized in H2O and studied spectroscopically after incorporation into the LOV domain of the blue light photoreceptor YtvA from Bacillus subtilis. The spectroscopic studies were paralleled by high‐level quantum chemical calculations. In solution, 8‐BrRF showed a remarkably high triplet quantum yield (0.97, parent compound riboflavin, RF: 0.6) and a small fluorescence quantum yield (0.07, RF: 0.27). For 8‐CF3RF, the triplet yield was 0.12, and the fluorescence quantum yield was 0.7. The high triplet yield of 8‐BrRF is due to the bromine heavy atom effect causing a stronger spin–orbit coupling. Theoretical calculations reveal that the decreased triplet yield of 8‐CF3RF is due to a smaller charge transfer and a less favorable energetic position of T2, required for intersystem crossing from S1 to T1, as an effect of the electron‐withdrawing CF3 group. The reconstitution of the LOV domain with the new flavins resulted in the typical LOV photochemistry, consisting of triplet state formation and covalent binding of the chromophore, followed by a thermal recovery of the parent state, albeit with different kinetics and photophysical properties. 相似文献
917.
Therése Klingstedt Dr. Cristiane Blechschmidt Dr. Anna Nogalska Dr. Stefan Prokop Bo Häggqvist Dr. Olof Danielsson Prof. W. King Engel Prof. Valerie Askanas Prof. Frank L. Heppner Dr. K. Peter R. Nilsson 《Chembiochem : a European journal of chemical biology》2013,14(5):607-616
Small hydrophobic ligands identifying intracellular protein deposits are of great interest, as protein inclusion bodies are the pathological hallmark of several degenerative diseases. Here we report that fluorescent amyloid ligands, termed luminescent conjugated oligothiophenes (LCOs), rapidly and with high sensitivity detect protein inclusion bodies in skeletal muscle tissue from patients with sporadic inclusion body myositis (s‐IBM). LCOs having a conjugated backbone of at least five thiophene units emitted strong fluorescence upon binding, and showed co‐localization with proteins reported to accumulate in s‐IBM protein inclusion bodies. Compared with conventional amyloid ligands, LCOs identified a larger fraction of immunopositive inclusion bodies. When the conjugated thiophene backbone was extended with terminal carboxyl groups, the LCO revealed striking spectral differences between distinct protein inclusion bodies. We conclude that 1) LCOs are sensitive, rapid and powerful tools for identifying protein inclusion bodies and 2) LCOs identify a wider range of protein inclusion bodies than conventional amyloid ligands. 相似文献
918.
Rönnholm Mats R. Hernández Carucci José R. Arve Kalle Eränen Kari Salmi Tapio 《Topics in Catalysis》2007,42(1-4):195-198
A silver/alumina catalyst was tested for its NO
x
reduction activity during oxygen-rich conditions and during variation in the input parameters (nitric oxide, octane and oxygen).
The experimental data using the microreactor was investigated by means of artificial neural networks (ANN). 相似文献
919.
R. Glowinski T. Kärkkäinen T. Valkonen A. Ivannikov 《Journal of scientific computing》2008,37(2):103-138
In this article, the denoising of smooth (H
1-regular) images is considered. To reach this objective, we introduce a simple and highly efficient over-relaxation technique
for solving the convex, non-smooth optimization problems resulting from the denoising formulation. We describe the algorithm,
discuss its convergence and present the results of numerical experiments, which validate the methods under consideration with
respect to both efficiency and denoising capability. Several issues concerning the convergence of an Uzawa algorithm for the
solution of the same problem are also discussed. 相似文献