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11.
Ionela Carazeanu Popovici Gabriel Prodan 《Journal of Sol-Gel Science and Technology》2012,63(3):457-462
Fresnoite (Ba2TiSi2O8, BTS) nano-particles were successfully synthesized at a low temperature of 900?°C by a modified Pechini sol?Cgel process with starting materials of Ba(NO3)2, Si(OC2H5)4 and Ti(OC3H7)4. The structural characterization of the precursors and derived synthesized oxide powders is done by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TG-DTG) and electron microscopy (SEM, EDX and TEM) studies. The effect of heat-treating temperature on the crystallinity of the fresnoite was investigated. Combined the XRD data and the strong FTIR peaks assigned to Ti?CO and Si?CO vibration, indicate the formation of fresnoite phase at a temperature of 900?°C. Also the nano-crystals size distribution was studied and the main diameter of nanoparticles was about 47?nm. 相似文献
12.
Cristina Bucur Romana Cerc Korošec Mihaela Badea Larisa Calu Mariana Carmen Chifiriuc Nicoleta Grecu Nicolae Stanică Dana Marinescu Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2013,113(3):1287-1295
Novel complexes of type M2LCl4·nH2O (M: Ni, n = 4; M: Cu, n = 2.5 and M: Zn, n = 1.5; L: ligand resulted from 1,3-phenylenediamine, 3,6-diazaoctane-1,8-diamine, and formaldehyde one-pot condensation) were synthesized and characterized. The ligand was also isolated and characterized. The complexes features have been assigned from microanalytical, electrospray ionization tandem mass spectrometry, IR, UV–vis, 1H NMR, and EPR spectra as well as magnetic data at room temperature. Simultaneous thermogravimetric/dynamic scanning calorimetry/evolved gas analysis measurements were performed to evidence the nature of the gaseous products formed in each step. Processes as water elimination, fragmentation, and oxidative degradation of the organic ligand as well as chloride elimination were observed during the thermal decomposition. The final product of decomposition was metal(II) oxide except for copper complex where CuCl remained also in the oxide network. The complexes exhibited an improved antibacterial activity in comparison with the ligand concerning both planktonic as well as biofilm-embedded cells. 相似文献
13.
Nilgun Demir Urkiye Akar Tarim Maria-Ana Popovici Zehra Nur Demirci Orhan Gurler Iskender Akkurt 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(2):1303-1307
The mass attenuation coefficients of water, bakelite and concrete sample defined in the simulation package were obtained using the FLUKA Monte Carlo code at 59.5, 80.9, 140.5, 356.5, 661.6, 1173.2 and 1332.5 keV photon energies. The results for the mass attenuation coefficients obtained by simulation have been compared with experimental and the theoretical ones and good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma-rays with the several energies in other materials. Also, the deposited energy by 661.6 keV photons at several thicknesses of each media was determined as being an important data for radiation shielding studies. 相似文献
14.
Julia Rebholz Peter Bonanati Udo Weimar Nicolae Barsan 《Analytical and bioanalytical chemistry》2014,406(16):3977-3983
A model for sensing with semiconducting metal oxide (SMOX)-based gas sensors was developed which takes the effect of the shape of the grains in the sensing layers into account. Its validity is limited to materials in which the grains of the SMOX sensing layer are large enough to have an undepleted bulk region (large grains). This means that in all experimental conditions, the SMOX properties ensure that the influence of surface phenomena is not extended to the whole grain. The model takes the surface chemistry and its impact on the electrical properties of the sensing material into consideration. In this way, it relates the sensor signal—defined as the relative change of the sensor’s conductance—directly to the concentration of the target gas and also exhibits meaningful chemical parameters, such as the type of reactive oxygen species, the reaction constants, and the concentration of adsorption sites. The validity of the model is confirmed experimentally by applying it to data gathered by measuring homemade sensors in relevant conditions. 相似文献
15.
Nicoleta E. Mircescu Haibo Zhou Nicolae Leopold Vasile Chiş Natalia P. Ivleva Reinhard Niessner Andreas Wieser Christoph Haisch 《Analytical and bioanalytical chemistry》2014,406(13):3051-3058
Based on molecular-specific surface-enhanced Raman scattering (SERS) spectroscopy we were able to discriminate between rough and smooth strains of Escherichia coli and Proteus mirabilis bacteria. For this purpose, bacteria have been immobilized through electrostatic forces by inducing a positive charge on the glass slide. This way, SERS spectra on bacterial biomass and also on single bacteria could be recorded in less than 2 h, by using concentrated silver nanoparticles as SERS-active substrate. Single-bacterium SERS spectral fingerprints showed to be sensitive to the presence of the O-antigen at strain level and to the microorganisms growth phase. By using principal component analysis (PCA) on the SERS spectra recorded from E. coli and P. mirabilis, these two uropathogens could be fairly discriminated. 相似文献
16.
Mihaela Badea Larisa Calu Mariana Carmen Chifiriuc Coralia Bleotu Alexandra Marin Sebastian Ion Gabriela Ioniţă Nicolae Stanică Luminiţa Măruţescu Veronica Lazăr Dana Marinescu Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1145-1157
A series of complexes of type [ML(CH3COO)(OH2)2] (M: Co, Ni; HL: 2-[(E)-1H-1,2,4-triazol-3-ylimino)methyl]phenol)) and [M2L2(CH3COO)2(OH2)n] (M: Cu, n = 2; M: Zn, n = 0) were synthesised by template condensation. The compounds were characterised with microanalytical, ESI–MS, IR, electronic, EPR spectra and magnetic data at room temperature. Based on the IR and ESI–MS spectra, a dinuclear structure with the acetate as bridge was proposed for Cu(II) and Zn(II) complexes. The dinuclear structure of Cu(II) complex is also consistent with both magnetic behaviour and EPR spectrum. The thermal analyses have evidenced processes as water elimination, acetate decomposition, as well as oxidative degradation of the Schiff base. The final decomposition product was the most stable metal oxide as indicated by powder X-ray diffraction. The cobalt and copper compounds exhibited a broad spectrum of antibacterial activity towards both planktonic and biofilm-embedded cells. The complexes exhibit a low cytotoxicity except for Cu(II) species that induces the early apoptosis for the HEp 2 cells. 相似文献
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The off-resonance effect and its influence on the reversibility between two quantum subsystems in interaction (single mode cavity field and a three-level atom in cascade configuration) are studied. The partial restoration condition is found at which these radiators can restore their diagonal moments, while the non-diagonal ones remain correlated after the interaction process. 相似文献
20.
Madalan AM Roesky HW Andruh M Noltemeyer M Stanica N 《Chemical communications (Cambridge, England)》2002,(15):1638-1639
A novel heterospin system, [(CuL)2Gd(TCNQ)2].TCNQ-.CH3OH.2CH3CN, is obtained by reacting the mononuclear complex, [CuL], with gadolinium(III) nitrate, followed by the substitution of the nitrato ions with anionic organic radicals. 相似文献