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41.
Stability of rare‐earth‐doped spherical yttria‐stabilized zirconia synthesized by ultrasonic spray pyrolysis 下载免费PDF全文
Nazia Nafsin Hui Li Elisabeth W. Leib Tobias Vossmeyer Pieter Stroeve Ricardo H. R. Castro 《Journal of the American Ceramic Society》2017,100(10):4425-4434
Phase stability is one of the crucial requirements for any material that can be used at elevated temperature applications such as thermal barrier coating (TBC). The most traditional TBC material, partially stabilized zirconia, limits the operating temperature due to its phase transformation. Conversely, the low thermal conductivity of fully stabilized zirconia (YSZ) may enable effective reduction in the surface temperature on the coated component, while avoiding deleterious phase transitions, although still being subjected to sintering and grain growth. It has been reported that addition of rare‐earths as dopants to YSZ can significantly increase resistance to grain growth at high temperature. Keeping this under consideration, this work investigates the role of rare‐earths (lanthanum and gadolinium) in increasing thermal stability of YSZ microspheres, the building blocks for high‐temperature photonics for reflective TBC. The spheres were produced by ultrasonic spray pyrolysis, and the doping led to significant improvement of stability by significant inhibition of grain growth. While the individual dopants showed significant growth and sintering inhibition up to 900°C, co‐doping with 4% (in mol) of each (Gd and La) led to coarsening resistance up to 1000°C for 3 hours, when particles retained reasonable spherical features with nanometric crystallite sizes. 相似文献
42.
Fetal alcohol syndrome (FAS) is the leading birth defect in the United States, yet few treatment options exist for children afflicted with this disorder. Although play therapy has demonstrated its efficacy with numerous special populations, as of today, no research has been conducted on its use with FAS. This article presents an overview of current data on FAS, an argument for the use of child-centered play therapy for children diagnosed FAS, and suggests areas of research needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
43.
44.
Rajendra P. Maskey Ines Kock Mohamed Shaaban Iris Grün-Wollny Elisabeth Helmke Frank Mayer Irene Wagner-Döbler Hartmut Laatsch 《Polymer Bulletin》2002,49(2-3):87-93
Summary
A new group of low-molecular weight channel-forming oligo(hydroxybutyric acids) (cPHBs, 1 with n = 8–30; main component MW ≈ 1300 dalton) was isolated from microorganisms of different origin. Inclusion bodies were
electron-microscopically visible in cells in the state of autolysis, not in cells in the exponential phase of growth. cPHB
and high-molecular poly(l3-hydroxybutyric acid) (sPHB) is cleaved by phenylethylamine and forms the corresponding monomeric
hydroxybutyramide and – under drastic conditions, the crotylamide. One of these compounds, the 3-hydroxy-N-phenethyl-butyramide
(5), was isolated as a new natural product now.
Received: 28 March 2002/Revised version: 26 July 2002/ Accepted: 26 July 2002
RID="*"
ID="*"Marine Bakterien, XVII. XVI: R.P. Maskey, R.N. Asolkar, E. Helmke, and H. Laatsch, Chalcomycin B, a new antibiotic from
a marine Streptomyces sp. B7064. J. Antibiot., submitted 2002
Correspondence to Hartmut Laatsch, e-mail: hlaatsc@gwdg.de, Fax: +49-551-399660 相似文献
45.
Addicks E Mazitschek R Giannis A 《Chembiochem : a European journal of chemical biology》2002,3(11):1078-1088
Integrins, a widely expressed family of heterodimeric cell surface adhesion proteins, are expressed in a variety of cell types. They play a decisive role in cell-cell adhesion or cell to extracellular matrix adhesion events. Antagonists of alpha(v)beta(3) or alpha(IIb)beta(3) integrin may have a potential use in suppression of pathological processes. We present the synthesis of novel tricyclic benzodiazepinedione-based RGD analogues, which were subsequently tested in a solid-phase receptor assay in order to investigate their binding affinities towards alpha(v)beta(3) and alpha(IIb)beta(3) integrin. 相似文献
46.
Westerhausen René; Woerner Wolfgang; Kreuder Frank; Schweiger Elisabeth; Hugdahl Kenneth; Wittling Werner 《Canadian Metallurgical Quarterly》2006,20(3):272
The objective of the present study was to examine the role of the corpus callosum (CC) in dichotic listening. For this purpose, 40 right-handed healthy male participants were assessed with morphological and diffusion tensor imaging, which yielded macrostructural (midsagittal area) and microstructural (mean diffusion, fractional anisotropy) measures of the total CC and predefined subregions. Applying the standard consonant-vowel Bergen Dichotic Listening Test (including 3 different attentional instructions), the authors found dichotic listening performance to be substantially related to the integrity of the CC at both macro- and microstructural levels. Results indicate a dual role of the CC; it is relevant not only for the stimulus-driven (bottom-up) transfer of left-ear input to the left hemisphere but also for its attentional (top-down) modulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
47.
Elisabeth 《Data & Knowledge Engineering》2002,41(2-3):247-272
Natural language and databases are core components of information systems. They are related to each other because they share the same purpose: the conceptualization aspects of the real world in order to deal with them in some way. Natural language processing (NLP) techniques may substantially enhance most phases of the information system lifecycle, starting with requirements analysis, specification and validation, and going up to conflict resolution, result processing and presentation. Furthermore, natural language based query languages and user interfaces facilitate the access to information for anyone and allow for new paradigms in the usage of computerized services. This paper investigates the use of NLP techniques in the design phase of information systems. Then, it reports on data base querying and information retrieval enhanced with NLP. 相似文献
48.
Ana Celia Mota Elisabeth Dumont James L. Smith 《Journal of Low Temperature Physics》1999,117(5-6):1477-1481
We have found a sharp transition at T
c2
= 350 mK in the vortex creep rate of a single crystal of (U
1–x
Th
x
)Be
13
with T
c
= 523 mK (x = 0.0275). For T T
c2
, no creep of vortices is observed in a time scale of 105
s, while for T
c2
< T < T
c
, vortices creep at very high rates (30% of decay from a metastable configuration in the first 105
s at T = 400 mK). The sharp transition occurs at the same temperature at which the second jump in the specific heat appears in these samples. Similar low levels of creep rates have been reported by us in the low–T superconducting phase of UPt
3.1 相似文献
49.
Elisabeth Blickstad 《Food microbiology》1984,1(3):177-185
The water activity (aw) of a cured minced meat mixture was reduced with NaCl or glycerol + NaCl and the products stored in air, N2 or CO2 at 4°C. The lower the aw, the lower was the growth rate of the total microflora except when aw was reduced below 0·98 with glycerol and products were stored in CO2, when the growth rate was independent of aw. At aw 0·94 NaCl was more effective than glycerol + NaCl in reducing the growth rate. In air the final microflora of products stored at aw ≤0·96 consisted primarily of yeasts while at 0.98 aw, both Lactobacillus (62%) and yeasts (38%) were found. In CO2 and N2Lactobacillus predominated at 0·94–0·98 aw when 2% NaCl or NaCl + glycerol were used. At 0·94 aw, produced using 6% NaCl, a heterogenous final microflora was found, including Micrococcus and Staphylococcus. An increase in the microbial shelf-life of meat products may be obtained by reducing the aw, particularly for use with storage in N2- and CO2-atmospheres. The type of solute chosen to regulate aw may affect the solubility of CO2, which in turn affects the shelf-life. 相似文献
50.
Elisabeth Chassaing Nicolas Portail Anne-france Levy Guillaume Wang 《Journal of Applied Electrochemistry》2004,34(11):1085-1091
Ni–Mo nanocrystalline layers were electrodeposited using direct current from citrate–ammonia solutions. The quartz crystal microbalance investigation confirms that the discharge process starts with hydrogen evolution before the onset of the alloy deposition. The grain size was estimated from X-ray line broadening. It decreases when the molybdenum content is increased. It is smaller for layers deposited at pH 9.5 than 8.5. The microhardness exhibits a maximum close to 800 Vickers for Mo around 17 wt%. For higher Mo a softening is observed showing a deviation from Hall-Petch behaviour due to small grain size. In deaerated hydrochloric solutions, the layers show a large passivation domain without any pitting. The corrosion currents as well as the passivation currents, higher than for the bulk Hastelloy B alloy, decrease when Mo is increased. 相似文献