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961.
Two data fusion strategies (variable and decision level) combined with a multivariate classification approach (Partial Least Squares-Discriminant Analysis, PLS-DA) have been applied to get benefits from the synergistic effect of the information obtained from two spectroscopic techniques: UV-visible and 1H NMR. Variable level data fusion consists of merging the spectra obtained from each spectroscopic technique in what is called “meta-spectrum” and then applying the classification technique. Decision level data fusion combines the results of individually applying the classification technique in each spectroscopic technique. Among the possible ways of combinations, we have used the fuzzy aggregation connective operators. This procedure has been applied to determine banned dyes (Sudan III and IV) in culinary spices. The results show that data fusion is an effective strategy since the classification results are better than the individual ones: between 80 and 100% for the individual techniques and between 97 and 100% with the two fusion strategies. 相似文献
962.
制备了两个系列不同镍钼负载量的NiMo 催化剂,并用X 衍射、N2 物理吸附和透射电镜进行了表征。以二苯并噻吩
为模型硫化物,在高压固定床微型反应器上对该NiMo 催化剂的加氢脱硫性能进行了评价,研究了MoS2 形貌与催化剂加氢脱
硫选择性之间的关系。结果表明,镍钼负载量对MoS2 形貌有明显的影响。Mo18Ni4 催化剂(含18% MoO3 和4% NiO)上
MoS2 呈多级层状结构,具有较高的加氢脱硫活性和优异的加氢脱硫选择性。加氢选择性与催化剂上活性组分MoS2 的堆积层
数相关联呈很好的线性关系;堆积层数越多,其加氢选择性也越高。 相似文献
为模型硫化物,在高压固定床微型反应器上对该NiMo 催化剂的加氢脱硫性能进行了评价,研究了MoS2 形貌与催化剂加氢脱
硫选择性之间的关系。结果表明,镍钼负载量对MoS2 形貌有明显的影响。Mo18Ni4 催化剂(含18% MoO3 和4% NiO)上
MoS2 呈多级层状结构,具有较高的加氢脱硫活性和优异的加氢脱硫选择性。加氢选择性与催化剂上活性组分MoS2 的堆积层
数相关联呈很好的线性关系;堆积层数越多,其加氢选择性也越高。 相似文献
963.
Sperb F Werlang IC Margis-Pinheiro M Basso LA Santos DS Pasquali G 《Applied biochemistry and biotechnology》2011,165(2):652-665
Erythropoietin (EPO) is a hormone belonging to a group of hematopoietic growth factors that control the proliferation and
differentiation of bone marrow cells. It induces the production of erythrocytes, thereby increasing the amount of circulating
hemoglobin and oxygen. Previous attempts to transgenically express human EPO in plants failed to succeed because the plants
exhibited abnormal morphology and infertility. In the present work, we describe the generation of fertile transgenic tobacco
plants able to express a synthetic version of human EPO. A 582-bp fragment of the human EPO gene was synthesized using a PCR-based
method and ligated into pCR-Blunt. After sequencing, the human EPO fragment was transferred to pWUbi.tm1 and the expression
cassette was then transferred to the binary vector pWBVec4a. After Agrobacterium-mediated transformation of Nicotiana tabacum SR1 plants, integration of the transgene into T0 and T1 plant genomes was confirmed by PCR. The human EPO gene was found to be expressed in tobacco leaves at the mRNA and protein
levels. Self-crossing allowed us to obtain T1 plants exhibiting Mendelian segregation of the transgene. None of the plants presented any kind of malformation or deformity. 相似文献
964.
Di Santo G Blankenburg S Castellarin-Cudia C Fanetti M Borghetti P Sangaletti L Floreano L Verdini A Magnano E Bondino F Pignedoli CA Nguyen MT Gaspari R Passerone D Goldoni A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(51):14354-14359
Scratching the surface: Formation of a monolayer of 2H-tetraphenylporphyrins (2H-TPP) on Ag(111), either by sublimation of a multilayer in the range 525-600?K or by annealing (at the same temperature) a monolayer deposited at room temperature, induces a chemical modification of the molecules. Rotation of the phenyl rings into a flat conformation is observed and tentatively explained, by using DFT calculations, as a peculiar reaction due to molecular dehydrogenation. 相似文献
965.
Iglesias-Juez A Kubacka A Fernández-García M Di Michiel M Newton MA 《Journal of the American Chemical Society》2011,133(12):4484-4489
A combination of time-resolved X-ray absorption spectroscopy (XAS), hard X-ray diffraction (HXRD), diffuse reflectance infrared spectroscopy (DRIFTS), and mass spectrometry (MS) reveals a series of size-dependent phenomena at Pd nanoparticles upon CO/(NO+O(2)) cycling conditions. The multitechnique approach and analysis show that such size-dependent phenomena are critical for understanding Pd CO elimination behavior and, particularly, that different Pd(I) and Pd(0) centers act as active species for a size estimated by XAS to be, respectively, below and above ca. 3 nm. The relative catalytic performance of these two noble metal species indicates the intrinsic higher activity of the Pd(I) species. 相似文献
966.
The molecular anions, Li(3)O(-) and Na(3)O(-) were produced by laser vaporization and studied via anion photoelectron spectroscopy. Li(3)O(-) and Na(3)O(-) are the negative ions of the super-alkali neutral molecules, Li(3)O and Na(3)O. A two-photon process involving the photodetachment of electrons from the Li(3)O(-) and Na(3)O(-) anions and the photoionization of electrons from the resulting Li(3)O and Na(3)O neutral states was observed. The assignment of the Li(3)O(-) photoelectron spectrum was based on computational results provided by Zein and Ortiz [J. Chem. Phys. 135, 164307 (2011)]. 相似文献
967.
In a recent work [Gao et al., Appl. Phys. Lett. 134, 113902 (2007)], we reported a novel DNA separation method by tethering DNA chains to a solid surface and then stretching the DNA chains with an electric field. The anchor is such designed that the critical force to detach a DNA chain is independent of its length. Because the stretching force is proportional to the DNA net charge, a gradual increase of the electric field leads to size-based removal of the DNA strands from the surface and thus DNA separation. Originally proposed for separation of long double-stranded DNA chains (>10 000 bps), this method has been proven useful also for short single-stranded DNA fragments (<100 bases) for which the fluctuation force induced by the solvent becomes significant. Here we show that the fluctuation force can be approximately represented by a gaussian model for tethered DNA chains. Analytical expressions have been derived to account for the dependence of the fluctuation force on the surface confinement, the polymer chain length, and the DNA tethering potential. The theoretical predictions are found to coincide with experiment. 相似文献
968.
969.
Zahra Shariatinia Mauricio F. Erben Carlos O. Della Védova Majid Abdous Saman Azodi 《Structural chemistry》2011,22(6):1347-1352
Intermolecular interactions between α-, β-glucose, and methacrylic acid (MAA) have been investigated. Twenty-two possible
conformations have been optimized at the DFT(B3LYP) level of theory with the 6-31G(d) basis set. The geometrical parameters
for the most stable configurations of hydrogen bonding sites in the optimized systems have been determined. The binding energies
ΔE
bind have been calculated at the MP2/6-311++G(d,p) level of approximation taking into account the basis set superposition error
(BSSE) and the zero-point vibrational energies corrections. Results indicate that the most stabilized complexes form hydrogen
bonds either through carboxylic and hemiacetal oxygen atoms acting as proton acceptors. Both, α- and β-anomers are studied
in the pyranose six-membered ring. In all complexes, the nuclear quadrupole coupling constants (χ) for 17O nuclei were obtained about 10.0 MHz, while for the 2H atoms they vary from ≈200.0 to ≈350.0 kHz. 相似文献
970.
Carbone M Li Y Irace C Mollo E Castelluccio F Di Pascale A Cimino G Santamaria R Guo YW Gavagnin M 《Organic letters》2011,13(10):2516-2519
Two indole alkaloids, phidianidines A (1) and B (2), exhibiting an uncommon 1,2,4-oxadiazole ring linked to the indole system, have been isolated from the marine opisthobranch mollusk Phidiana militaris. The structures of the two metabolites have been elucidated by spectroscopic techniques. Phidianidines exhibit high cytotoxicity against tumor and nontumor mammalian cell lines in in vitro assays. 相似文献