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排序方式: 共有279条查询结果,搜索用时 31 毫秒
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Mirjana Dimitrievska Fredrik S. Hage Simon Escobar Steinvall Alexander P. Litvinchuk Elias Z. Stutz Quentin M. Ramasse Anna Fontcuberta i Morral 《Advanced functional materials》2021,31(41):2105426
Earth-abundant and environmentally friendly semiconductors offer a promising path toward low-cost mass production of solar cells. A critical aspect in exploring new semiconducting materials and demonstrating their enhanced functionality consists in disentangling them from the artifacts of defects. Nanowires are diameter-tailored filamentary structures that tend to be defect-free and thus ideal model systems for a given material. Here, an additional advantage is demostrated, which is the determination of the band structure, by performing high energy and spatial resolution electron energy-loss spectroscopy in aloof and inner beam geometry in a scanning transmission electron microscope. The experimental results are complemented by spectroscopic ellipsometry and are excellently correlated with first principles calculations. This study opens the path for characterizing the band structure of new compounds in a non-destructive and prompt manner, strengthening the route of new materials discovery. 相似文献
35.
Quality of corn germ oil obtained by aqueous enzymatic extraction 总被引:21,自引:0,他引:21
Mirjana Bocevska Djerdj Karlović Jovan Turkulov Draginja Pericin 《Journal of the American Oil Chemists' Society》1993,70(12):1273-1277
Aqueous enzymatic extraction of corn germ oil was investigated. By applying hydrothermal pretreatment of corn germ, it was
possible to inactivate native enzymes present in the germ and to loosen its structure. The corn was then ground and treated
with enzymes. After the oil had been released by the enzyme reaction, it was separated by centrifugation. The quality of oil
obtained by enzymatic extraction (Pectinex Ultra SP-L at 37°C, pH 5.2, for 6 h) was good. The oil had 1.5% free fatty acids;
a total content of oxidation product value of 8.1; light yellow color (AOCS photometric color, 12.7; dominant wavelength λD=575 nm); 0.022% phosphatides; 1350 mg/kg total tocopherol; and an oxidative stability value (Rancimat test, 100°C) of 14.6
h. 相似文献
36.
Slobodan?P.??erbanovi? Ivona?R.?Grguri? Mirjana?Lj.?Kijev?anin Aleksandar?Z.?Tasi? Bojan?D.?Djordjevi?Email author 《Korean Journal of Chemical Engineering》2004,21(4):858-866
A comparison of the performances of two different approaches of cubic equations of state models, based on a classical van
der Waals and mixing rules incorporating theG
E
equation, was carried out for correlation of Vapor-Liquid Equilibria (VLE), HE and C
P
E
data alone, and simultaneous correlation of VLE+HE, VLE+C
P
E
, HE +C
P
E
and VLE+HE +C
P
E
data for the diethers (1,4-dioxane or 1,3-dioxolane) with n-alkane systems. For all calculations the Peng-Robinson-Stryjek-Vera
cubic equation of state (PRSV CEOS) was used. A family of mixing rules for the PRSV CEOS based on the Modified van der Waals
one-fluid mixing rule (MvdW1) and two well-known CEOS/GE mixing rules (MHV1 and MHV2), was considered. The NRTL equation, as the GE model with linear or reciprocal temperature dependent parameters, was incorporated in the CEOS/GE models. The results obtained by the CEOS/GE models exhibit significant improvement in comparison to the MvdW1 models. 相似文献
37.
Olivera B. Miloevi Mirjana K. Mirkovi Dragan P. Uskokovi 《Journal of the American Ceramic Society》1996,79(6):1720-1722
Spherical fine (micrometer and submicrometer in size) homogeneous BaTiO3 powders were synthesized from ethanol: water solutions of BaCl2 and TiCl4 using the spray-pyrolysis technique. Two different atomizers—twin-fluid and ultrasonic, with a resonant frequency of 2.5 × 106 Hz—were used for mist generation. Hollow spherical particles containing a certain amount of unreacted BaCl2 phase and having a mean particle diameter of 2.5 μm were obtained at 1173 K using a twin-fluid atomizing system. Decomposition of precursors and their transition to the cubic BaTiO3 phase occurred, even at 973 K in the case of the ultrasonic atomizing system. For the initial droplet size of 2.2 μm and residence time of ∼60 s, spherical BaTiO3 particles with the mean particle diameter of 0.53 μm were obtained. A BaTiO3 formation mechanism has been proposed as a reaction between TiO2 and BaCl2 rather than a reaction of oxides. 相似文献
38.
The paper analyses the 1923 Belgrade Master Plan's preparation and implementation process, a significant moment in Belgrade's political and urban history when, after the First World War, the city lost its centuries-long border position, becoming the capital of a newly established extended country, the Kingdom SHS, later the Kingdom of Yugoslavia. The goal of government and city authorities was to create a representative national capital and overcome the city's existential and functional problems. Crucial to the process was the Association of Serbian Architects and Engineers’ organization of an international competition in 1921–1922. Twenty-two projects were submitted, from Vienna, Paris, Budapest, Berlin, Zurich, Prague, etc. First prize was not awarded, but 18 were rewarded and purchased. These represented the basis for creating a final plan, supervised by G. P. Kovalevsky. The 1923 Master Plan introduced very innovative and modern approaches to solving the city's problems and improving residential areas, traffic, and greenery. The paper discusses the plan's realization, its extensive changes and partial implementation, which greatly influenced later city development. Despite obstacles, the plan initiated some important and progressive ideas whose impact was vital for the functional transformation of the city and its realization represents Belgrade's modern urban heritage. 相似文献
39.
Abazović ND Montone A Mirenghi L Janković IA Comor MI 《Journal of nanoscience and nanotechnology》2008,8(2):613-618
In this study, nitrogen-doped titanium dioxide (TiO2) powders were synthesized in two ways: by heating of titanium hydroxide with urea and by direct hydrolysis of titanium tetraisopropoxide (TTIP) with ammonium hydroxide. The samples were characterized by structural (XRD), analytical (XPS), optical (UV/Vis absorption/reflection and Raman spectroscopy) and morphological (SEM, TEM) techniques. The characterization suggested that the doped materials have anatase crystalline form without any detectable peaks that correspond to dopants. The absorption threshold of titanium dioxide was moved in the visible range of optical spectrum from 3.2 eV to 2.20 eV. Particle sizes of synthesized powders were obtained from XRD measurements and from TEM data ranging from 6-20 nm. XPS and Raman spectroscopy were used for detection of nitrogen in doped samples. 相似文献
40.
Hafner A Filipović-Grcić J Voinovich D Jalsenjak I 《Drug development and industrial pharmacy》2007,33(4):427-436
Conventional and composed promethazine-loaded microspheres were prepared by spray drying of chitosan solution systems and double water-in-oil-in-water (W/O/W) emulsion systems, respectively. Double emulsions were prepared in two different feed concentrations, with chitosan dissolved in both water phases, and ethylcellulose dissolved in oil phase. Swelling and bioadhesive properties of the microspheres depended on the chitosan content, type and the feed concentration of spray-dried system. Results obtained suggested that better ethylcellulose microcapsules with promethazine in the chitosan matrix were formed when less concentrated emulsion systems were spray-dried. Thus, in case of such a system, with ethylcellulose/chitosan weight ratio of 1:2, prolonged promethazine release was obtained. 相似文献