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161.
162.
Slobodan D. Dolić Dragana J. Jovanović Krisjanis Smits Biljana Babić Milena Marinović-Cincović Slavica Porobić Miroslav D. Dramićanin 《Ceramics International》2018,44(15):17953-17961
Monoclinic scheelite-type BiVO4 is currently considered as one of the most promising non-titania photocatalysts, wheras tetragonal zircon-type BiVO4 is still poorly understood. Herein, a new and simple synthetic approach was applied and nanostructured single-phase zircon-type BiVO4 was successfully prepared by a controllable ethylene-glycol colloidal route. In addition, nanostructured monoclinic scheelite-type BiVO4 powders were also fabricated through annealing of the as-prepared samples. A comparative study of the two BiVO4 polymorphs was conducted and it turned out that the novel synthetic approach had a significant impact on porosity and photocatalytic performance of zircon-structured BiVO4. All the prepared materials, as-prepared and annealed, were mesoporous, while measured values of specific surface area of some zircon-structured samples (~34?m2/g) were ~7 times higher than those reported thus far for this phase. Interestingly, for the first time, zircon-type BiVO4, previously considered to be a poor photocatalyst, exhibited a better overall performance in degradation of methyl orange compared to monoclinic scheelite-type BiVO4. Hence, it could be expected that the here-presented synthesis and observations will both arouse interest in scarcely studied tetragonal zircon-type BiVO4 and facilitate as well as speed up further research of its properties. 相似文献
163.
Liga Stipniece Valentina Stepanova Inga Narkevica Kristine Salma-Ancane Adrian R. Boyd 《Journal of the European Ceramic Society》2018,38(2):761-768
Mg-substituted hydroxyapatite (HAp) bioceramic microspheres were prepared by spray drying and subsequent processing at 1173, 1273 and 1373 K. Influence of various Mg substitution levels (up to 0.84 ± 0.10 wt%) on physicochemical properties of the HAp bioceramic microspheres was evaluated. Obtained results were used for the elucidation of the compositional and structural characteristics of the microspheres in conjunction with adsorption of protein, namely, bovine serum albumin (BSA). The primary difference among the microspheres processed at various temperature was the presence or absence of the micropores (<2 nm in diameter) and mesopores (between 2 and 50 nm). Presence of the micro- and mesopores resulted in higher specific surface area (SSA), enhanced solubility, i.e., ion release, and, accordingly, increase in the amount of BSA adsorbed on the microspheres. Furthermore, the BSA adsorption capacity of the microspheres decreased with increasing Mg content despite of higher SSA. 相似文献
164.
You Zhou Yu-ichi Yoshizawa Kiyoshi Hirao Zoltán Lenčéš Pavol Šajgalík 《Journal of the European Ceramic Society》2011,31(1-2):151-157
LaSi3N5:Eu2+ phosphor powders were prepared by a highly efficient combustion synthesis method. It was found that the compositions of the raw powder mixtures had great influences on the phase compositions and particle morphologies of the synthesized powders. By selecting appropriate starting compositions and combustion parameters, single phase LaSi3N5:Eu2+ phosphors could be synthesized. When excited by a UV light, the LaSi3N5:Eu2+ phosphors emitted green light. The wavelength and intensity of the emission spectra were affected by the amount of Eu2+ dopant. With increasing amount of Eu2+ dopant, concentration quenching could occur and emission spectra shifted to longer wavelengths. 相似文献
165.
A mathematical model is derived and disdussed that represents the structural properties of the alternative linearity and of the triangular block structural connectivity of the sets of differential equations, associated with the machines in the numerical integration of short- and long-term dynamics. In order to take into consideration the structural properties of the model, a one-step decomposition method for the numerical integration of short- and long-term dynamics is proposed. The method can be applied not only to the numerical integration of short- and long-term dynamics but also to all other cases when the model of the dynamic system is alternative-linear and triangular block connected. Numerical stability, accuracy and computation speed are the major advantages of this method, making it suitable for many applications, including the dynamic security analysis of power systems. 相似文献
166.
Surfactants are often used in supramolecular chemistry, due to their ability to self-organize. Surfactant molecules aggregate spontaneously and reversibly to adopt a defined intermolecular arrangement. In this work, general phase behavior, adsorption and association in aqueous mixtures of dodecylammonium chloride, DACl and sodium 4-(1-pentylheptyl) benzenesulfonate, NaDBS, were studied by a combination of techniques including surface tension and conductivity measurements, light scattering and optical microscopy. The strong synergistic properties of the system were brought out with the Regular Solution Theory. Various colloidal objects are observed in wide range of composition: conventional small vesicles, large giant multilamellar or multivesicular vesicles. An excess of NaDBS provides extremely large tubular and elongated multilamellar vesicles. The new catanionic 1:1 complex, dodecylammonium-4-(1-pentylheptyl) benzenesulfonate, formed in the equimolar conditions is a result of intramolecular charge neutralization. The thermal properties of this solid compound were examined by thermal polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. The most probable ion-pair amphiphilic cluster of the crystal smectic phase, at room temperature, consists of ionic groups formed in ordered layers with dodecyl chains packed into somewhat disordered layers, tilted to the layer plane. 相似文献
167.
168.
Anticancer Potential of (Pentamethylcyclopentadienyl)chloridoiridium(III) Complexes Bearing κP and κP,κS‐Coordinated Ph2PCH2CH2CH2S(O)xPh (x=0–2) Ligands 下载免费PDF全文
Gerd Ludwig Ivan Ranđelović Dr. Danijela Maksimović‐Ivanić Dr. Sanja Mijatović Mirna Z. Bulatović Dr. Djordje Miljković Prof. Marcus Korb Prof. Dr. Heinrich Lang Prof. Dr. Dirk Steinborn Prof. Dr. Goran N. Kaluđerović 《ChemMedChem》2014,9(7):1586-1593
Iridium(III) complexes of the type [Ir(η5‐C5Me5)Cl2{Ph2PCH2CH2CH2S(O)xPh‐κP}] (x=0–2; 1 – 3 ) and [Ir(η5‐C5Me5)Cl{Ph2PCH2CH2CH2S(O)xPh‐κP,κS}][PF6] (x=0–1; 4 and 5 ) with 3‐(diphenylphosphino)propyl phenyl sulfide, sulfoxide, and sulfone ligands Ph2PCH2CH2CH2S(O)xPh were designed, synthesized, and characterized fully, including X‐ray diffraction analyses for complexes 3 and 4 . In vitro studies against human thyroid carcinoma (8505C), submandibular carcinoma (A253), breast adenocarcinoma (MCF‐7), colon adenocarcinoma (SW480), and melanoma (518A2) cell lines provided evidence for the high biological potential of the neutral and cationic iridium(III) complexes. Neutral iridium(III) complex 5 proved to be the most active, with IC50 values up to about 0.1 μM , representing activities of up to one order of magnitude higher than cisplatin. Using 8505C cells, apoptosis was shown to be the main mechanism through which complex 5 exerts its tumoricidal action. The described iridium(III) complexes represent potential leads in the search for novel metal‐based anticancer agents. 相似文献
169.
Two novel potentially biodegradable thermoplastic polyurethane elastomers with unique structure and morphology were prepared from modified oleic acid. The hardness and mechanical properties were controlled by adjusting the soft segment concentration (SSC). Epoxidized methyl oleate was converted to methyl‐9‐ or ?10‐hydroxystearate (hydroxystearate) by catalytic hydrogenation. The formed hydroxystearate was transesterified with 1,6‐hexanediol to obtain polyesterpolyol with molar mass 2500. Segmented polyurethanes with 50% and 70% SSC were prepared using the prepolymer method by reacting polyesterpolyol with diphenylmethane diisocyanate and 1,4‐butanediol as chain extender. Thermal and mechanical properties of the polymers indicated good micro‐phase separation. Both soft and hard segments displayed a certain degree of crystallization. Tensile strengths were 18 and 2.4 MPa for samples with 50% and 70% SSC, respectively. Elongations of 130% (50% SSC) and 43% (70% SSC) were somewhat lower than in comparable materials, presumably due to lower molar mass. © 2014 Society of Chemical Industry 相似文献
170.
Lj.R. Đačanin M.D. Dramićanin S.R. Lukić-Petrović D.M. Petrović M.G. Nikolić T.B. Ivetić I.O. Gúth 《Ceramics International》2014
In this research we prepared nanocrystalline YNbO4:Eu3+ phosphor, i.e. nanophosphor, powder using an efficient mechanochemical method followed by annealing. X-ray diffraction analysis revealed that YNbO4:Eu3+ crystallizes in monoclinic structure C2/c where, from the point of view of A and B in ABO4 compounds, cation coordination can be noted as [6+2, 4+2]. Crystallite size of about 40 nm, was estimated using Debye Scherrer's equation. Raman spectroscopy with 785 and 532 nm excitation wavelengths is performed to record a majority of materials phonon modes and to provide more in depth understanding of the YNbO4 structure. Scanning electron microscopy observations indicate that the mechanical treatment during synthesis is causing non-uniformity of the powder microstructure. High resolution photoluminescent measurements upon UV excitation showed intense emission coming from f–f transitions of the europium ion with the lifetime of 0.68 ms, suggesting that the obtained YNbO4:Eu3+ is a good potential phosphor. A comparison of emissive properties with microcrystalline YNbO4:Eu3+ was made and it showed higher values of emission intensity and lifetime of the nanocrystalline sample. 相似文献