Biotic Replacements: Extinction or Clade Interaction?
John C. Briggs; Thinking of Biology: Biotic replacements—extinction or clade interaction?, BioScience, Volume 48, Issue 5, 1 May 1998, Pages 389–395, https://do
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Gamma-ray Irradiation Effects on Corrosion Rates of Stainless Steel in Boiling Nitric Acid Containing Ionic Additives
Irradiation effects of γ-rays on corrosion rates of type 304ULC stainless steel in 9×10−3 mol/m3 boiling nitric acid containing an ionic additive of multivalence elements of Ce(IV), Cr(VI) or Ru(III) were studied by measuring weight losses of specimens immersed under the 60Co γ-ray irradiation of 1 kC/(kg·h) (4MR/h).…
Processing of Ceramic Matrix Composites by Pulsed-CVI and Related Techniques
P-CVD/CVI is used to densify model pores and to fabricate Nicalon/SiC microcomposites with pyrocarbon or (PyC-SiC)/sub n/ multilayered interphases. The gaseous precursors are hydrocarbons (CH/sub 4/ or C/sub 3/H/sub 8/) for pyrocarbon and CH/sub 3/SiCl/sub 3/-H/sub 2/ for SiC. The best densification conditions for 60;…
Caractérisation physico-chimique et étude du frittage d'une argile destinée à l'élaboration de membranes de filtration tangentielle
Les procédés de filtration tangentielle sont actuellement reconnus comme des techniques de séparation de haute performance depuis le laboratoire jusqu'à la production industrielle. le cur de ces techniques est la membrane. Le présent travail a pour objectif de mettre au point des membranes en argile à bas prix de revi…
The synthesis of poly(3,4-dihydroxystyrene) and poly[(sodium 4-styrenesulfonate)-co-(3,4-dihydroxystyrene)]
Poly(2-methoxy-4-vinylphenol), polyMVP, and poly[(sodium 4-styrenesulfonate)-co-(2-methoxy-4-vinylphenol)], poly(SSS/MVP), were synthesized by radical polymerization using Vazo-64 or tributylborane as initiator. Poly(3,4-dihydroxystyrene) and poly[(sodium 4-styrenesulfonate)-co-(3,4-dihydroxystyrene)] were obtained by…
Interaction of GaSe with GaAs(111): Formation of heterostructures with large lattice mismatch
We have studied the epitaxial growth of GaSe, a layered van der Waals material, on GaAs, a zinc-blende-structure semiconductor. This heterostructure exhibits a 6% lattice mismatch, and is a prototypical example of van der Waals epitaxy, where the weak van der Waals interaction allows the misfit to be accommodated with…
Structural and Optical Properties of the System (Sr,Eu)5(PO4)3(Cl,F)
Mixed crystals of the composition Sr5−yEuy(PO4)3Cl1−xFx with 0 ≤ x ≤ 1 and 0 ≤ y ≤ 0.05 were prepared by solid state reaction. The crystal structure, optical properties at room temperature, and the emission spectra of the polycrystalline materials at liquid nitrogen temperature are investigated. The structure paramete…
Catalytic Decomposition of H 2 O 2 over a γ-Irradiated CuO–ZnO/Al 2 O 3 System
A CuO–ZnO/Al 2 O 3 , catalyst sample was prepared by wet impregnation methods using Al(OH) 3 , zinc and copper nitrate solutions followed by drying at 110°C and calcination at 600°C. The nominal molar composition of the resulting material was calculated to be 0.25CuO · 0.03ZnO/Al 2 O 3 Samples of this solid were expos…
Crystallographic Data of a New Phase of Dicalcium Silicate
Unit‐cell parameters and the space group of a new phase of dicalcium silicate (Ca 2 SiO 4 ) were determined by using powder X‐ray diffractometry and selected‐area electron diffraction techniques. This phase could be synthesized via the dissociation of hydrothermally synthesized alpha‐Ca 2 (SiO 4 H)OH at temperatures o…
Microstructure and Dielectric Properties of YMnO 3 Thin Films Prepared by Dip‐Coating
YMnO 3 thin films with Y/Mn ratios from 1.00/1.05 to 1.00/0.90 were prepared by dip‐coating from solution, in which starting materials were refluxed, and the effects of the Y/Mn ratio on the structure and dielectric properties of YMnO 3 thin films were investigated. XRD measurements indicated that the films with the Y…
Thermoelectric Properties and Hall Effect of Bi2Te3-xSex Polycrystalline Materials Prepared by a Hot Press Method
Bi 2 Te 3- x Se x (0≦ x <1) polycrystalline solids are prepared by a hot press method and their thermoelectric properties are studied. The samples show the maximum value of Z = 2.3×10 -3 K -1 at x =0.22. The lattice thermal conductivity is smaller than that of a single crystal. The lattice constant and power factor…
Rheological properties and the interface in polycarbonate/impact modifier blends: Effect of modifier shell molecular weight
Core-shell impact modifiers are used to enhance the impact strength of thermoplastics such as polycarbonate. The shell of the modifier is designed specifically to interact with the matrix polymer because interfacial adhesion between the modifier and matrix is important in improving the impact strength. Several methods…
Germanium-rich SiGe bulk single crystals grown by the vertical Bridgman method and by zone melting
Silicon–germanium single crystals with a Si content up to 10 at. % have been grown by the vertical Bridgman technique in a monoellipsoid mirror furnace. Single crystal regions up to 50 at. % have been realized by zone melting in a double ellipsoid mirror furnace. The typical high temperature gradients of radiation hea…
Pressureless Sintering of B<sub>4</sub>C-TiB<sub>2</sub> Ceramic Composites
Pressureless sintering of the B 4 C ceramics containing 0-25 vol.% TiB 2 phase was studied in the isothermal and constant heating rate regimes. The B 4 C-TiB 2 composites were pressureless sintered to a relative density of 97.5% at 2100°C. It was found that the heating rate had no visible effect on the density. A new…
Novel Polar Liquid Crystals with Very Low Birefringence Based ontrans-1,3-Dioxane Building Blocks
Liquid crystals with one or more trans-1,3-dioxane building blocks (see Figure) combine high dielectric anisotropy with low birefringence and favorable mesogenic and viscoelastic properties. A new, building-block-oriented synthetic strategy is described that offers convenient access to trans-1,3-dioxane–based core str…
Sub 100 Nanosecond Pretilted Planar-to-Homeotropic Reorientation of Nematic Liquid Crystals under High Electric Field
The pretilted planar-to-homeotropic reorientation transition of nematic liquid crystals with positive dielectric anisotropy is achieved with a record fast risetime, as fast as 40 ns, by employing a customized electro-optic cell with small area and cell gap and with metal-coated electrodes and by applying electric fiel…
Properties of ZnO:In film prepared by sputtering of facing ZnO:In and Zn targets
ZnO:In films were prepared by a sputtering method with targets facing. The lowest resistivity film is obtained at a substrate temperature of 150 °C using a ZnO target doped with 3 wt % In2O3. At substrate temperatures above 300 °C the resistivity of the film increases as the carrier concentration decreases. This impli…
Nature of adhesive bonding via interchain transesterification reactions (ITR)
Secondary ion mass spectrometry (SIMS) was used to determine the nature of the adhesive bonding which occurs through interchain transesterification (ITR) in thermosetting polyester materials (TS) and in liquid crystalline polyester polymers (LCP). An all aromatic copolyester thermoset was prepared as a deuterated and…
ID14 `Quadriga', a Beamline for Protein Crystallography at the ESRF
The ESRF undulator beamline ID14 'Quadriga' is dedicated to monochromatic macromolecular crystallography. Using two undulators with 23 mm and 42 mm periods and a minimum gap of 16 mm installed on a high-beta section, it will provide high-brilliance X-ray beams at around 13.5 keV, as well as a wide tuneability between…
A predictive model for the penetration force of a woven fabric by a needle
Proposes an algorithm for the computation of maximum needle penetration force; it introduces the direct dependence of penetration force on fabric structural parameters and warp and weft geometrical and mechanical properties. Uses the approach to the simulation of local deformation of woven material which accounts for…