摘要:
The combination of one or more high reduction drafts with controlled, low back tensions increases the range of deformation conditions over which dimensional tolerances and Je may be optimized. The method comprises the steps of: first, providing a precursor article comprising a metal matrix surrounding a plurality of filaments extending along the length of the article and comprising precursors to a desired superconducting ceramic; next, roll working the precursor article during a breakdown stage at a back tension less than the elastic to plastic transition threshold of the composite during at least one high reduction roll working draft, and, then, sintering the rolled article to obtain the desired superconducting ceramic. In a preferred embodiment, the rolling step further comprises rolling the article at a front tension less than the elastic to plastic transition threshold of the rolled, unsintered article.
摘要:
A reduced coefficient of friction, preferably created by ideal lubrication conditions, may advantageously be employed in the breakdown deformation of a precursor to a multifilamentary superconducting composite, particularly in combination with one or more high reduction breakdown drafts, to improve composite homogeneity and significantly increase the range of deformation conditions over which dimensional tolerances and Je may be optimized. Precursor composites made by this method exhibit reduced microhardness variability and fewer and less serious transverse filament defects than composites made by prior art methods. The method comprises the steps of: first, providing a precursor article comprising a metal matrix surrounding a plurality of filaments extending along the length of the article and comprising precursors to a desired superconducting ceramic; next, roll working the precursor article during a breakdown stage at a predetermined pressure and a coefficient of friction less than about 0.2, preferably less than 0.01, and preferably less than about 0.001 during each roll working draft, and, then, sintering the rolled article to obtain the desired superconducting ceramic. The coefficient of friction is preferably obtained by interposing a lubricant between the precursor article and one or more rolls, most preferably under conditions which create ideal lubrication conditions.
摘要:
The present invention provides a (Bi,Pb)SCCO-2223 oxide superconductor composite which exhibits improved critical current density and critical current density retention in the presence of magnetic fields. Retention of critical current density in 0.1 T fields (77 K, .perp. ab plane) of greater than 35% is disclosed. Significant improvements in oxide superconductor wire current carrying capacity in a magnetic field are obtained by subjecting the oxide superconductor composite to a post-processing heat treatment which reduces the amount of lead in the (Bi,Pb)SCCO-2223 phase and forms a lead-rich non-superconducting phase. The heat treatment is carried out under conditions which localize the lead-rich phase at high energy sites in the composite.
摘要:
The present invention provides a (Bi,Pb)SCCO-2223 oxide superconductor composite which exhibits improved critical current density and critical current density retention in the presence of magnetic fields. Retention of critical current density in 0.1 T fields (77 K, ⊥ ab plane) of greater than 35% is disclosed. Significant improvements in oxide superconductor wire current carrying capacity in a magnetic field are obtained by subjecting the oxide superconductor composite to a post-processing heat treatment which reduces the amount of lead in the (Bi,Pb)SCCO-2223 phase and forms a lead-rich non-superconducting phase. The heat treatment is carried out under conditions which localize the lead-rich phase at high energy sites in the composite.
摘要:
Methods for elucidating biopolymer interactions with known and/or unknown small molecules (e.g. candidate drug compounds) are disclosed. These methods utilize novel (usually motile) organisms transformed with one or more heterologous biopolymer sequences. Biopolymer expression is promoted in cells mediating movement in said organism, generally dually-promoted in paired sets of cells mediating oppositely-directed movement. Modulation of motility in the resultant organism due to the presence of small molecules demonstrates small molecule interaction with said natural and/or mutated biopolymer. Analyzed in a chemical gradient, one or more interacting small molecule species can be identified by oriented migration, even in the presence of one or more non-interacting small molecule species. A competing and/or interfering biopolymer can be introduced without obscuring the motility signal. Methods described herein have utility for the discovery of novel therapeutic compounds (drug discovery), for the improvement of existing therapeutic compounds (drug refinement), and for the precise identification of small molecule binding sites on biopolymers via mutagenesis (structural elucidation). A specific embodiment, a Nematode Olfaction-based Structural Elucidation (NOSE) assay, is described herein.
摘要:
This invention is directed to a composition for catalyzed oligonucleotide cleavage comprising a synthetic non-naturally occurring oligonucleotide compound. The compound comprises nucleotides whose sequence defines a conserved group II intron catalytic region and nucleotides whose sequence is capable of hybridizing with a predetermined oligonucleotide target sequence to be cleaved, such target sequence not being present within the compound. The composition also includes an appropriate oligonucleotide co-factor. Preferably, the conserved group II intron catalytic region is a group II intron domain I catalytic region. In one embodiment the conserved group II intron domain I catalytic region may further comprise a conserved portion of a group II intron domain II, a group II intron domain III, a group II intron domain IV, a group II intron domain V, or a group II intron domain VI. The invention is also directed to methods of treatment and methods of use of such compounds.