Search results for "structures"
showing 10 items of 4815 documents
Efficacy of raw implementation and reduction dose protocols in CT colonoscopy: a single centre 4 years retrospective review
2015
Aims and objectives Methods and materials Results Conclusion Personal information References
Crystal structure determination of 1-pentanol from low-temperature powder diffraction data by Patterson search methods
2005
5 pages.-- PACS: 61.66.Hq; 61.50.Lt
Inorganic/organic hybrid nanoparticles synthesized in a two-step radiation-driven process
2022
In this work, we have synthesized inorganic-organic hybrid nanoparticles via radiation synthesis of inorganic nanoparticles (Ag and CeO2) in aqueous dispersions containing radiation-synthesized poly(N-vinyl pyrrolidone) (PVP) nanogels (NG). The experiments show that there are strong interactions between the inorganic precursors (Ag+ and Ce3+) and the nanogel prior to irradiation. The two hybrid systems (Ag/NG and CeO2/NG) were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD confirms the formation of crystalline Ag and CeO2. TEM reveals that the inorganic nanoparticles are evenly distributed in/on the nanogel. Both XRD and TEM show that size of the…
Rare earth element contents of Jurassic fish and reptile teeth and their potential relation to seawater composition (Anglo-Paris Basin, France and En…
2002
The rare earth element (REE) chemistry of Jurassic shelf seawater from western Europe (Anglo-Paris Basin) was investigated by analyzing the fish and reptile teeth deposited in shallow to deeper water (<200 m) environments. REE patterns in apatites are controlled by the host sediments. Vertebrate teeth sampled from the siliciclastic sediments (calcareous sandstones and shales) show flat shale-normalized REE patterns that reflect the dominant influence of the continental source from which the REE were derived. Carbonate deposits, protected from the clastic sources, contain fish and reptile teeth whose REE patterns reflect more accurately the REE composition of the overlying water column. The …
N-Glycosyl Amides as Glycosyl Donors in Stereoselective Glycosylation Reactions
2004
Due to their high stability, N-glycosyl amides have so far not been considered as glycosyl donors for glycosylation reactions. Two new procedures for the cleavage of the anomeric amide functionality under mild reaction conditions and further stereoselective in situ conversions of the activated glycosyl donors with alcohols and amines to give β-configured O- and N-glycosides are described in this article.
An efficient probe for sensing different concentration ranges of glutathione based on AIE-active Schiff base nanoaggregates with distinct reaction me…
2018
Abstract A novel tetraphenylethene-diketopyrrolopyrrole Schiff base (TPE-DPP) was synthesized by one-pot protocol. Based on thiol group and acid-base property of glutathione, nanoaggregates of TPE-DPP for sensitive and selective detection of diff ;erent concentration ranges of glutathione by two distinct reaction mechanisms was reported. It showed a turn-on mode of fluorescence signals towards low concentration of GSH by hydrolysis of TPE-DPP, but a ratiometric mode of fluorescence signal was elicited towards high concentration of GSH by addition reaction of thiol with TPE-DPP. What’s more, the probe was successfully utilized for monitoring GSH in living cells.
A Realist Philosophy of Mathematics
2007
The realism/anti-realism debate is one of the traditional central themes in the philosophy of mathematics. The controversies about the existence of the irrational numbers, the complex numbers, the infinitesimals, etc. will be familiar to all who are acquainted with the history of mathematics. This book aims mainly at presenting and defending a non-Platonist form of mathematical structural realism which, in the respect of the history of mathematics, harmonizes with a plausible epistemology that naturally arises from it.
Structures de déformation induites par surpressions de fluide dans les environnements sous-glaciaires et marin profonds : implications paléoenvironne…
2014
Soft-sediment deformation structures (SSDs) occur in unconsolidated sediments, during or shortly after deposition. SSDs are abundant in subglacial and deep-marine environments because of the development of fluid overpressure. Case studies of these two sedimentary environments were used (1) to reconstruct palaeoenvironments from SSDS, and (2) to define the impacts of SSDS on glacial morphologies and (3) petrophysical properties.(1) Analyses of strain regimes, deformation mechanisms, and chronologies in SSDs served to improve palaeoenvironmental reconstructions. These structures were used as proxys to estimate variations of ice flow velocities, ice thickness, meltwater production, and positio…
The Polynominal Approximation in Design of Rectification of the Roadway Overhead Crane
1993
In this chapter a new method for processing surveying results of the overhead crane in horizontal plane is presented.
Staggering Periodic Replenishments
1999
The paper deals with the problem of staggering periodic replenishment orders associated to different frequencies. The particular multi-item, instantaneous replenishment case with known demand is considered. The practical interest for such a problem is twofold: staggering orders allows both a reduction of the costs incurred in holding goods and an efficient use of space in warehouses. Some specific models allowing staggering are considered and, for them, theoretical results and properties are provided.