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排序方式: 共有228条查询结果,搜索用时 31 毫秒
171.
Janez Martincic 《世界建筑导报》2019,(2)
<正>项目情况:设计2013年,开工2015年,竣工2016年项目计划:冬季小屋建设单位:PD Bovec建筑面积:9.7平方米安装实际建构面临的挑战是如何在偏远场地以1:1的比例安装真实的物体和庇护所,并且研究对极端的天气、极端温度变化、雨雪及起伏的地形的反应。风、雪、山体滑坡、地形、天气等恶劣条件下,需要特定的建筑形式、结构和概念来应对它们。该场地只能通过攀爬或者 相似文献
172.
The mechanism of Cu2+ loading into commercially available natural HEU-type and synthetic LTA-type zeolites for their possible use in environmental processes, such as water and air treatment applications, was studied. Elemental analysis, SEM/EDXS, XRD, XAS and XPS analyses revealed 4-fold coordination of Cu2+ cations with oxygen atoms in the pores, a predominant location of copper atoms on the surface of crystallites and retained crystallinity of zeolites throughout the processes. The post-treatment of Cu2+-loaded samples with HCl and/or NaCl solutions confirmed the predominantly reversible sorption of copper on zeolites from aqueous solutions by ion-exchange mechanism and, therefore, excellent regeneration possibilities for both types of zeolites. Furthermore, with the calcination of exhaust metal-loaded zeolites, catalysts for total toluene oxidation reaction, as a model VOC pollutant, were obtained. 相似文献
173.
Rui Machado Sérgio Godinho Janez Pirnat Nuno Neves Pedro Santos 《Landscape Research》2018,43(5):652-664
Landscape transformations have been a central topic in landscape ecology due to their influence on ecosystem services and biodiversity conservation. Landscape dynamics can be very complex and one of the most difficult issues to analyse is the contribution and the effects of landscape composition and configuration changes to the overall impact. We enhanced an existing approach designed to assess landscape transformation via metrics combination. Based on the area and the number of patches, we defined a Landscape Dynamics Typology (LDT) with eight different dynamics. The agro-forestry areas dynamics between 1990 and 2006, in Portugal, is presented as a practical example to show the implementation steps and the outputs obtained. A diagnostic tree is provided to help identify which dynamics are present. This new method provides detailed results concerning the location of the different dynamics within a landscape. The LDT is a versatile tool and is able to accommodate upgrades. 相似文献
174.
Catalysis Letters - CeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested... 相似文献
175.
Marko Hrovat Darko Belavi
Jaroslaw Kita Janez Holc Jena Cilenek Silvo Drnovek 《Journal of the European Ceramic Society》2009,29(15):3265-3271
The electrical and microstructural characteristics of 1 kΩ/sq. thick-film NTC thermistors (4993, EMCA Remex) fired either on LTCC (low-temperature cofired ceramic) substrates or buried within LTCC structures were evaluated. The thermistors were fired at different temperatures to study the influence of firing temperature on the electrical characteristics. The results were compared with the characteristics obtained on alumina substrates. The sheet resistivities were higher than the resistivities of thick-film thermistors on alumina substrates. The increase of the sheet resistivities was attributed to the diffusion of the glass phase from the rather glassy LTCC substrates into the NTC thermistors. This was confirmed by EDS analyses. However, the increase in the resistivity was linked to an increase of the beta factors. Therefore, the results show that the evaluated NTC thermistors on LTCC substrates can be used for temperature sensors in MCM-Cs as well as in MEMS LTCC structures. When the thermistors were buried in the LTCC substrates, the LTCC structures delaminated during firing, leading to high sheet resistivities and high noise indices. This delamination is attributed to the different sintering rates of the NTC and LTCC materials. 相似文献
176.
Harvey Amorín Hana Uršič Pablo Ramos Janez Holc Rodrigo Moreno Daniel Chateigner Jesús Ricote Miguel Algueró 《Journal of the American Ceramic Society》2014,97(2):420-426
Pb(Mg1/3Nb2/3)O3–PbTiO3 is used as a model system of perovskite solid solutions with very high piezoelectric response at tailored morphotropic phase boundaries to demonstrate the processing of textured ceramics by ceramic‐only technology. A novel homogeneous templated grain growth approach that uses conventional ceramic procedures and a single‐source nanocrystalline powder for the matrix and also for obtaining the templates is described. Two batches of (100) faceted cube‐shaped microcrystals with average sizes of 27 and 10 μm were successfully used as templates, and aligned by tape casting for the processing of <001>‐textured Pb(Mg1/3Nb2/3)O3–PbTiO3 piezoelectric ceramics. Materials with effective piezoelectric coefficients up to 1000 pC/N and ferroelectric properties approaching those of single crystals are obtained. 相似文献
177.
Darko Belavic Marina Santo Zarnik Janez Holc Marko Hrovat Marija Kosec Silvo Drnovsek Jena Cilensek Srecko Macek 《International Journal of Applied Ceramic Technology》2006,3(6):448-454
Lead zirconate titanate (PZT) is a piezoelectric material that can sense or respond to mechanical deformations and can be used in ceramic electro-mechanical systems (C-MEMS). The microstructural, electrical, and piezoelectric characteristics of thick PZT films on low-temperature cofired ceramics (LTCC) and alumina substrates were studied. The PZT composition was prepared with low-melting-point additives in order to decrease the sintering temperature and to be compatible with thick-film technology. The integration of the PZT thick-film materials on ceramic substrates could lead to degradation of the PZT's characteristics due to the interactions between an active PZT layer and a substrate, particularly with glassy LTCC material. To minimize the interactions with LTCC substrates, an intermediate PZT barrier layer was integrated. The value of the piezoelectric coefficient d 33 was found to be up to 120 pC/N on an alumina substrate and approximately 50 on an LTCC substrate. Based on these results, a cantilever-type actuator was designed and fabricated on alumina substrates. Under an applied voltage of 200 V, the maximum tip deflection was about 5 μm. 相似文献
178.
Catalytically active surface of small nickel (min 99 wt%) plates for steam methane reforming was enhanced by successive temperature programmed oxidation−reduction (TPO−TPR) pretreatment and combined physical vapor deposition of Pt and Al2O3. The effect of annealing time, temperature, order and number of coatings on the catalytic activity was investigated by means of a pulse technique at the reaction temperature of 760 °C. The most active and stable surface phases resulted after the successively deposited layers of Pt, Al2O3, and Pt had been annealed for 12 h onto 2-cycle TPO−TPR pretreated nickel plate at the temperature of 700 °C in a circulating atmosphere of N2. The durability performance of the so-prepared surface phases on a specifically structured plate catalyst element (diameter 43 mm and length 42 mm) was tested in a tubular reactor for some 70 h in temperature range 500−650 °C. Deactivation was mainly caused by carbon surface deposition. 相似文献
179.
Martina Durcik Prof. Päivi Tammela Michaela Barančoková Assist. Prof. Tihomir Tomašič Assoc. Prof. Janez Ilaš Prof. Danijel Kikelj Nace Zidar 《ChemMedChem》2018,13(2):186-198
ATP‐competitive inhibitors of DNA gyrase and topoisomerase IV are among the most interesting classes of antibacterial drugs that are unrepresented in the antibacterial pipeline. We developed 32 new N‐phenylpyrrolamides and evaluated them against DNA gyrase and topoisomerase IV from E. coli and Staphylococcus aureus. Antibacterial activities were studied against Gram‐positive and Gram‐negative bacterial strains. The most potent compound displayed an IC50 of 47 nm against E. coli DNA gyrase, and a minimum inhibitory concentration (MIC) of 12.5 μm against the Gram‐positive Enterococcus faecalis. Some compounds displayed good antibacterial activities against an efflux‐pump‐deficient E. coli strain (MIC=6.25 μm ) and against wild‐type E. coli in the presence of efflux pump inhibitor PAβN (MIC=3.13 μm ). Here we describe new findings regarding the structure–activity relationships of N‐phenylpyrrolamide DNA gyrase B inhibitors and investigate the factors that are important for the antibacterial activity of this class of compounds. 相似文献
180.
Danjela Kuscer Andraž Kocjan Maja Majcen Anton Meden Kristian Radan Janez Kovač Barbara Malič 《Ceramics International》2019,45(8):10429-10437
This study was designed to better understand the microstructural and phase evolution of lead-free sodium potassium niobate based piezoceramics with a nominal composition (K0.5Na0.5)0.99Sr0.005NbO3 (KNNSr) during pressure-less spark plasma sintering followed by post-annealing in oxygen. The as-sintered samples were dark-coloured and electrically conductive as a result of partial reduction of Nb5+ to Nb4+ and formation of oxygen vacancies confirmed by X-ray photoelectron and Raman spectroscopy. The Rietveld refinement analysis showed that the as-sintered samples contained two perovskite phases with monoclinic Pm unit cell and slightly different unit-cell parameters. The microstructure with sub-micrometre-sized grains unambiguously confirmed that rapid heating and short dwell time hindered the grain growth. We found that post-annealing the samples at 950?°C in oxygen led to improvement in functional properties. The samples became white-coloured, the both perovskite unit cells decreased as a result of re-oxidation, while the microstructure remained essentially unchanged. The KNNSr sintered at nominal sintering temperature of 1300?°C for 3?min and post-annealed possessed a relative density of 88% and dielectric and piezoelectric properties similar to those of the conventionally sintered samples. Our findings contribute to the understanding of pressure-less spark plasma sintering of sodium potassium niobate-based materials and suggest that arrested grain growth and minimisation of alkali evaporation not necessarily lead to dense ceramic. 相似文献