127 research outputs found
Revue de l'instruction publique en France et dans les pays Ă©trangers
15 novembre 18501850/11/15 (A9,N151)-1850/11/15
Additional file 5: Figure S3. of Lineage-specific duplications of NBS-LRR genes occurring before the divergence of six Fragaria species
The Ks ranges of NBS-LRR genes in six Fragaria species. The Ks ranges between paralogs (A), orthologs (B) and all genes (C) in TNLs and the Ks ranges between paralogs (D), orthologs (E) and all genes (F) in non-TNLs among the six species. (JPEG 1759ĂÂ kb
Formation of a âHard Microemulsionâ and Its Role in Controllable Synthesis of Nanoparticles within a Functional Polymer Matrix
Microemulsions are often used in the synthesis of nanoparticles in solution. In this work, we put forward the concept of a âhard microemulsionâ, which is based on the differential partitioning of water and ethanol solvent molecules inside functional polymer matrices. When the mixture of water and organic solvent enters the functional polymer, the liquid molecules should partition to different regions. Water should concentrate in the microdomains rich in hydrophilic functional groups, forming water-enriched cores, whereas organic solvents should localize near the alkyl polymer skeleton, forming organic liquid enriched outer layers. From a macroscopic view, the swollen polymer matrix is divided into numerous âmicrodropletsâ, resembling frozen water-in-oil microemulsions. We define such a structure as a âhard microemulsionâ. The water-enriched microdroplets may act as templates for synthesizing inorganic nanoparticles. We demonstrate the utility of hard microemulsions for the controllable synthesis of silver and platinum nanoparticles inside different macroreticular functional polymers
Early Devonian alkaline intrusive complex from the northern North China craton: a petrological monitor of post-collisional tectonics
<p>Laser ablation inductively coupled plasma mass spectrometry zircon UâPb dating and geochemical data document the Early Devonian
Sandaogou alkaline complex (409 Ma) from the northern margin of the North China craton. The rock suite includes pyroxene syenite,
quartz syenite and monzonite. These rocks exhibit high contents of K<sub>2</sub>O (5â13 wt%), strong enrichments in large ion lithophile elements and light REE, slightly negative Eu anomalies, and pronounced
depletions in high field strength elements. They are characterized by moderate <sup>87</sup>Sr/<sup>86</sup>Sr<sub>i</sub> ratios of 0.7052â0.7071, low Δ<sub>Nd</sub>(t) values of â12.7 to â17.9 and zircon Δ<sub>Hf</sub>(t) values from â27.8 to â32.3. These geochemical features and quantitative isotopic modelling suggest that they might have
been formed through simultaneous fractional crystallization and lower crustal assimilation of a metasomatized mantle-derived
alkali basaltic magma. These trachytic rocks, together with the Middle Devonian alkaline rocks and maficâultramafic complex
from neighbouring regions, constitute a linear post-collisional magmatic belt along the northern North China craton, possibly
formed under a tectonic regime of slab breakoff. They serve not only as a magmatic milestone for marking the termination of
Early Palaeozoic orogenic cycle around the northern North China craton, but also as a spatial tracer for locating the position
of the potential ancient slab breakoff at the surface.
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α-Sulfonyloxylation of 1,3-dicarbonyl compounds utilizing hypervalent iodine(iii) reagent: Construction of quaternary carbon center
<p>An efficient method for direct α-sulfonyloxylation of various sterically hindered 1,3-dicarbonyl compounds has been developed under mild reaction conditions. The yields of desired products is up to 90% and a plausible mechanism was accordingly proposed.</p
Decoding Neoarchaean to Palaeoproterozoic tectonothermal events in the Rangnim Massif, North Korea: regional correlation and broader implications
<p>Any knowledge about Archaean to Palaeoproterozoic magmatic and metamorphic events in North Korea has the potential to make a significant difference to our understanding of the early tectonic configuration and evolution of East Asia. This zircon UâPb dating and Hf isotopic study documents multiple Neoarchaean to Palaeoproterozoic tectonothermal events from the meta-igneous complex in the Machollyong âGroupâ of the Rangnim Massif. Two tonalitic-trondjemitic gneiss samples record a crystallization age of meta-igneous protoliths at ca. 2.56 Ga and multiple migmatization and metamorphism from 2.52 to 1.85 Ga. A meta-dolerite sample yields a magmatic emplacement age of ca. 1.83 Ga. <i>In situ</i> zircon Hf isotopic data indicate that most zircons from the gneiss samples have <i>Δ</i><sub>Hf</sub>(<i>t</i>) values from â16.9 to + 3.1 and crustal model ages from 2.84 to 3.73 Ga, whereas magmatic zircons from the meta-dolerite dike record <i>Δ</i><sub>Hf</sub>(<i>t</i>) values from â5.2 to + 5.2 and model ages of 2.05â2.44 Ga. The first-recognized Neoarchaean tonalitic-trondjemitic migmatite complex in the Rangnim Massif, together with previously identified tonalitic-trondhjemitic-granodioritic (TTG) rocks in the Rimjingang Belt and the coeval counterparts in western Gyeonggi massif, represents the oldest crustal nuclei in the Korean Peninsula. The multiple tectonothermal events in this study present reliable evidence not only for attesting to consanguinity of the basement between the Korean Peninsula and the North China Craton but also for defining the influence scope of the late Palaeoproterozoic orogeny in the Korean Peninsula.</p
Carboniferous appinitic intrusions from the northern North China craton: geochemistry, petrogenesis and tectonic implications
<p>Laser ablation inductively coupled plasma mass spectrometry zircon UâPb dating and geochemical study document Carboniferous
(<em>c</em>. 320â317 Ma) appinitic intrusions from the northern North China craton. The rock suite mainly consists of hornblende diorites
and monzodiorites, with an SiO<sub>2</sub> range from 46.8 to 55.4%. These rocks exhibit high alkali contents, strong enrichment in large ion lithophile elements and
light rare earth elements, and depletion in high field strength elements, with radiogenic <sup>87</sup>Sr/<sup>86</sup>Sr<sub>i</sub> ratios of 0.7058â0.7093, unradiogenic Ï”<sub>Nd</sub>(t) of â9.3 to â13.9 and zircon Ï”<sub>Hf</sub>(t) from â8.5 to â18.4. These geochemical features suggest that their generation may involve a distinctive two-stage process:
(1) a precursory metasomatism stage of mantle peridotites by melts from subduction-related sediments; (2) a delayed partial
melting stage probably initiated by post-subduction transcurrent movements along pre-existing lithospheric shear zones. These
mafic to intermediate intrusions, plus other coeval maficâ ultramafic complexes and high BaâSr granites from neighbouring
regions, not only witness a heterogeneously enriched subcontinental lithospheric mantle along the northern North China craton,
but also attest to a reworking-dominated metacratonic process within a post-subduction transtensional regime.
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Synthesis of Benzidine Derivatives via FeCl<sub>3</sub>·6H<sub>2</sub>OâPromoted Oxidative Coupling of Anilines
Under
open-flask conditions in the presence of commercially available
FeCl<sub>3</sub>·6H<sub>2</sub>O, N,N-disubstituted anilines
can be converted into diversely functionalized benzidines with yields
of up to 99%. Oxidative coupling was extended to N-monosubstituted
anilines, and the method was applied to the efficient preparation
of 6,6âČ-biquinoline. Mechanistic investigations have also been
performed to explain the observed reactivities
Polyhalogenation-Facilitated Spirolactonization at the <i>meta</i>-Position of Phenols
A novel dearomative spirolactonization/polyhalogenation
of phenols
that employs hypervalent iodine PhICl2 (iodobenzene dichloride)
as both an oxidant and chlorine source with an indispensable base,
or only using NBS (N-bromosuccinimide) without any
additives, is presented. Halide participations are a vital factor
in the cascade reaction of 3âČ-hydroxy-[1,1âČ-biphenyl]-2-carboxylic
acids with good selectivities and reactivities and induced the rapid
constructions of multiple Câhalogen bonds and directional CO
bonds in a one-step operation under mild conditions. In gaining a
good understanding of the mechanism, the increase in number of bromine
atoms was inferred rationally from the spirolactonization process,
assisted by DFT calculations and high-resolution mass spectrometry.
Mechanistic experiments suggest that the formation of a stable carbocation
intermediate plays a great role in the migration of oxygen to spirolactonization
DNA sequence chromatograms and cosegregation analysis of the R954C mutation with disease phenotype
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