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101.
A. C. M. Costa C. R. F. Castro M. J. Anjos R. T. Lopes 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):703-706
Summary Trace elements were determined in the surface waters of tributaries of the Sepetiba Bay, Brazil (Piraquê, Itá, S?o Francisco,
Guarda, Guandu Mirim, Vala do Sangue and Engenho Novo rivers) by total reflection X-ray fluorescence using synchrotron radiation
(SRTXRF). Eighteen trace elements could be determined in the dissolved and the suspended particulate phases: Al, Si, P, S,
Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb. The elemental concentration values were compared to the values recommended
by the Brazilian legislation. 相似文献
102.
Helberth Júnnior Santos Lopes Lucas Rodrigues Ramos Edson Luiz Silva 《Applied biochemistry and biotechnology》2017,183(3):712-728
This study evaluated the production of hydrogen and propionic acid in an expanded granular sludge bed (EGSB) reactor by co-fermentation of cheese whey (CW) and crude glycerol (CG). The reactor was operated at hydraulic retention time (HRT) of 8 h by changing the CW/CG ratio from 5:1 to 5:2, 5:3, 5:4, and 5:5. At the ratio of 5:5, HRT was reduced from 8 to 0.5 h. The maximum hydrogen yield of 0.120 mmol H2 g COD?1 was observed at the CW/CG ratio of 5:1. Increasing the CG concentration repressed hydrogen production in favor of propionic acid, with a maximum yield of 6.19 mmol HPr g COD?1 at the CW/CG ratio of 5:3. Moreover, by reducing HRT of 8 to 0.5 h, the hydrogen production rate was increased to a maximum value of 42.5 mL H2 h?1 L?1at HRT of 0.5 h. The major metabolites were propionate, 1,3-propanediol, acetate, butyrate, and lactate. 相似文献
103.
Leitão Jorge C. Parente Lopes João M. Viana Altmann Eduardo G. 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(10):1-10
The European Physical Journal B - A way to make financial models effective is by letting them to represent the so called “fat tails”, i.e., extreme changes in stock prices that are... 相似文献
104.
José Luis Palacios Nancy Lopes Garcia 《Journal of Mathematical Analysis and Applications》2003,286(1):230-236
Using the electric approach, we derive exact and asymptotic closed form formulas for hitting times in symmetric cases of the Moran's genetics model. 相似文献
105.
In this paper we prove the orbital stability of double solitons for the Benjamin-Ono equation. In the case of the KdV equation,
this stability has been proved in [17]. Parts of the proof given there rely on the fact that the Euler-Lagrange equations
for the conserved quantities of the KdV equation are ordinary differential equations. Since this is not the case for the Benjamin-Ono
equation, new methods are required. Our approach consists in using a new invariant for multi-solitons, and certain new identities
motivated by the Sylvester Law of Inertia. 相似文献
106.
Correlation spectroscopy as a tool for detecting losses of ligand elements in laser welding of aluminium alloys 总被引:1,自引:0,他引:1
T. Sibillano A. Ancona V. Berardi E. Schingaro P. Parente P.M. Lugar 《Optics and Lasers in Engineering》2006,44(12):1324-1335
The plasma plume induced during laser welding of metals is a mixture of metal vapour, coming from the vaporised weld pool surface and shielding gas. The influence of the shielding gas on the welded joints quality is not yet well understood and very few investigations, to the best of our knowledge, were addressed to study its role in case of welding of aluminium–magnesium alloys. In this paper we present a study of the dynamics of plasma plume produced in laser welding of 5xxx aluminium alloys by means of correlation spectroscopy. By our results we can correlate the influence of the welding speed, in case of ineffective gas shielding, to the loss of alloying elements. Finally, the results obtained are consistent with the EDX analysis performed in post-processing on the welded joints. 相似文献
107.
Hyperfine Interactions - Ferrosilicon is used in the dense medium separation of iron ore at Kumba resources, Sishen, South Africa. Due to high cost and losses that occur during use, maximum... 相似文献
108.
Fernando Coelho Demetrius VeroneseElizandra C.S Lopes Rodrigo C Rossi 《Tetrahedron letters》2003,44(30):5731-5735
In this communication we describe an easy and straightforward alternative method for the preparation of 3,4-substituted isoquinolin-1(2H)-ones, using Baylis-Hillman adducts as starting material. 相似文献
109.
P Cardon J P Parente Y Leroy J Montreuil B Fournet 《Journal of chromatography. A》1986,356(1):135-146
High-performance liquid chromatography has been applied to the separation of isomers of mono-, di-, tri- and tetrasialylated oligosaccharides derived from alpha 1-acid glycoprotein by hydrazinolysis. The separation of the sialyl-oligosaccharides on the basis of their negative charges was carried out with quaternary amine-bonded silica. Within each class, the anionic oligosaccharides were fractionated on the basis of their net carbohydrate content on alkylamine-modified silica using a mobile phase consisting of a mixture of acetonitrile and potassium dihydrogen phosphate with 0.01% of 1,4-diaminobutane or 0.01% of tetraethylpentamine. 相似文献
110.
Castro EV Novoselov KS Morozov SV Peres NM dos Santos JM Nilsson J Guinea F Geim AK Neto AH 《Physical review letters》2007,99(21):216802
We demonstrate that the electronic gap of a graphene bilayer can be controlled externally by applying a gate bias. From the magnetotransport data (Shubnikov-de Haas measurements of the cyclotron mass), and using a tight-binding model, we extract the value of the gap as a function of the electronic density. We show that the gap can be changed from zero to midinfrared energies by using fields of less, approximately < 1 V/nm, below the electric breakdown of SiO2. The opening of a gap is clearly seen in the quantum Hall regime. 相似文献