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Journal ArticleDOI

Phd by thesis

01 Apr 1988-Nature (Nature Publishing Group)-Vol. 332, Iss: 6166, pp 676-676
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

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Citations
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Journal Article
TL;DR: The Keller-Segel system describes the collective motion of cells which are attracted by a chemical substance and are able to emit it in its simplest form it is a conservative drift-diffusion equation coupled to an elliptic equation for the chemo-attractant concentration as mentioned in this paper.
Abstract: The Keller-Segel system describes the collective motion of cells which are attracted by a chemical substance and are able to emit it In its simplest form it is a conservative drift-diffusion equation for the cell density coupled to an elliptic equation for the chemo-attractant concentration It is known that, in two space dimensions, for small initial mass, there is global existence of solutions and for large initial mass blow-up occurs In this paper we complete this picture and give a detailed proof of the existence of weak solutions below the critical mass, above which any solution blows-up in finite time in the whole euclidean space Using hypercontractivity methods, we establish regularity results which allow us to prove an inequality relating the free energy and its time derivative For a solution with sub-critical mass, this allows us to give for large times an ``intermediate asymptotics'' description of the vanishing In self-similar coordinates, we actually prove a convergence result to a limiting self-similar solution which is not a simple reflect of the diffusion

560 citations

Book ChapterDOI
TL;DR: The main objective of field-cycling experiments [231, 367] is to obtain information on the spectral density of the fluctuating spin interactions in a frequency range as wide as possible as mentioned in this paper.

547 citations


Cites background from "Phd by thesis"

  • ...In Refs [99, 104] corresponding scaling arguments were established leading to SðkÞ / kdf23; ð71Þ with the surface fractal dimension df : Comparison of Eqs....

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  • ...[102] are irrelevant in these samples as was shown in Refs [36,98]....

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  • ...Variants of this configuration can be found in Refs [16,89,90]....

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  • ...Note also that chain dynamics of the lipid molecules themselves (see Section 9.9 and Refs [110 – 112]) did not perceptibly influence the water relaxation features....

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  • ...Typical examples of up-to-date relaxometer technology can be found in Refs [18,58]....

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Journal ArticleDOI
TL;DR: In this article, the results on metal-oxide surface chemistry also have implications for other fields such as environmental science, biophysics and chemical sensors, which reveal insight into the nature of the active sites and into the catalytic function of semiconducting oxides in general.

546 citations

Journal ArticleDOI
TL;DR: In this article, the basic photophysical phenomena together with representative examples such as nitroprusside derivatives, relevant spin crossover complexes, stilbenoid complexes and finally Prussian blue analogues are discussed.

535 citations


Cites background from "Phd by thesis"

  • ...is largest in the host with (Mn)2 [100]....

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Journal ArticleDOI
TL;DR: This Review highlights some recent promising activities and developments in heterogeneous catalysis using only carbon and carbon nitride as catalysts, which could be candidates for green chemistry with low emission and an efficient use of the chemical feedstock.
Abstract: The current established catalytic processes used in chemical industries use metals, in many cases precious metals, or metal oxides as catalysts. These are often energy-consuming and not highly selective, wasting resources and producing greenhouse gases. Metal-free heterogeneous catalysis using carbon or carbon nitride is an interesting alternative to some current industrialized chemical processes. Carbon and carbon nitride combine environmental acceptability with inexhaustible resources and allow a favorable management of energy with good thermal conductivity. Owing to lower reaction temperatures and increased selectivity, these catalysts could be candidates for green chemistry with low emission and an efficient use of the chemical feedstock. This Review highlights some recent promising activities and developments in heterogeneous catalysis using only carbon and carbon nitride as catalysts. The state-of-the-art and future challenges of metal-free heterogeneous catalysis are also discussed.

523 citations


Cites background from "Phd by thesis"

  • ...b) Various oxygen and nitrogen species and functional groups on the prismatic sites of a sp(2) carbon basal plane.([29])...

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References
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Journal ArticleDOI
TL;DR: A new family of highly fluorescent indicators has been synthesized for biochemical studies of the physiological role of cytosolic free Ca2+ using an 8-coordinate tetracarboxylate chelating site with stilbene chromophores that offer up to 30-fold brighter fluorescence.

21,582 citations


"Phd by thesis" refers background in this paper

  • ...members of this group were produced by Tsien and colleagues [1, 10, 11]....

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  • ...The introduction of Ca 2+ -sensitive fluorescent dyes more than twenty years ago and their permanent improvement [10] enabled investigators to gain unprecedented insights into the mechanisms of cellular signalling....

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ReportDOI
01 Nov 1990
TL;DR: This report will establish methods for performing a domain analysis and describe the products of the domain analysis process to illustrate the application of domain analysis to a representative class of software systems.
Abstract: : Successful Software reuse requires the systematic discovery and exploitation of commonality across related software systems. By examining related software systems and the underlying theory of the class of systems they represent, domain analysis can provide a generic description of the requirements of that class of systems and a set of approaches for their implementation. This report will establish methods for performing a domain analysis and describe the products of the domain analysis process. To illustrate the application of domain analysis to a representative class of software systems, this report will provide a domain analysis of window management system software.

4,420 citations

Journal ArticleDOI
TL;DR: The straw person model (SPM) as mentioned in this paper has been proposed to explain the orientation effects of active galactic nuclei (AGN) and quasars in the line of sight (LOS) images.
Abstract: Because the critical central regions of Active Galactic Nuclei (AGN) and quasars are strongly nonspherical but spatially unresolved, orientation effects have been the source of much confusion. In fact, it now appears that much of the variety in AGN types is just the result of varying orientation relative to the line of sight. We can define an extreme hypothesis,, the straw person model (SPM), in which there are two basic types of AGN: the radio quiets and the radio louds. For each type there is a range in intrinsic luminosity, and the luminosity controls some properties such as the Fanaroff and Riley classes. However, at a given intrinsic luminosity, all other properties such as spectroscopic classification and VLBI component speeds are ascribed to orientation. This model is only a caricature of the unification idea, and is already ruled out on many grounds, but it will be useful for organizing the discussion. I’ll describe what I consider to be convincing evidence that orientation effects are important and widespread. The true situation may be in some sense half way between the SPM and the hypothesis that orientation doesn’t affect classification at aIl. To us optimists, the orienration cup is half full rather than half empty. Although it is too soon to say for sure, the hypothesis that most objects’ classifications would be different if seen from other directions is a tenable one today.

4,005 citations

Journal ArticleDOI
TL;DR: This Review assembles the current knowledge on the isolation of microfibrillated cellulose from wood and its application in nanocomposites; the preparation of nanocrystalline cellulose and its use as a reinforcing agent; and the biofabrication of bacterial nanocellulose, as well as its evaluation as a biomaterial for medical implants.
Abstract: Cellulose fibrils with widths in the nanometer range are nature-based materials with unique and potentially useful features. Most importantly, these novel nanocelluloses open up the strongly expanding fields of sustainable materials and nanocomposites, as well as medical and life-science devices, to the natural polymer cellulose. The nanodimensions of the structural elements result in a high surface area and hence the powerful interaction of these celluloses with surrounding species, such as water, organic and polymeric compounds, nanoparticles, and living cells. This Review assembles the current knowledge on the isolation of microfibrillated cellulose from wood and its application in nanocomposites; the preparation of nanocrystalline cellulose and its use as a reinforcing agent; and the biofabrication of bacterial nanocellulose, as well as its evaluation as a biomaterial for medical implants.

3,452 citations

Journal ArticleDOI
TL;DR: The solid electrolyte interphase (SEI) is a protecting layer formed on the negative electrode of Li-ion batteries as a result of electrolyte decomposition, mainly during the first cycle as discussed by the authors.

2,386 citations