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A two-dimensional Navier-Stokes system with friction is considered in a large rect-angular periodic domain with area on the order of α?1, α → 0. Bounds for the dimension of the attractor are obtained, which are sharp both as α → 0 and v → 0, where v is the viscosity coefficient.  相似文献   
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Starting in 1989 an experiment was run at PSI to directly measure the final sticking probability in muon catalyzed dt fusion. This experiment was based on an active-target ionization chamber (IC) built at Gatchina, Russia, and an array of plastic neutron counters. In three runs approximately 5×106 isolated alpha signals were recorded with around one half of these occurring in the inner chamber region where we have more complete understanding of the systematic errors. Particularly from a long run in 1992 we were able to obtain a very clean sticking peak of some 5000 events. However, to reach an accurate value of sticking, all systematic effects and several major backgrounds had to be understood in detail. To this end a Monte Carlo code was written to simulate the full electrostatic environment of the IC and to recreate completely each signal type including the actual tritium decay noise from the live experiment. A slightly model dependent value of approx. 0.56±0.04% is obtained for final sticking.  相似文献   
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By comparing the positions of 19F shifts in pentafluoro complexes of do transition metals and non-transition elements in higher oxidation state complexes MF5L and EF5L with the positions of corresponding MF6 and EF6, the spectra of all the pentafluoro complexes can be divided into a few types which depend on the nature of L. Correlation of chemical shifts with structural data and force constants implies that the change in the bond strength of the fluorine and the central ion has opposite effects in the 19F NMR spectra of the complexes of transition and non-transition elements.  相似文献   
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To meet growing needs for high throughput gene expression profiling, we established a new automated high throughput TaqMan RT-PCR method for quantitative mRNA expression analysis. In this method, the Allegro( trade mark ) (Zymark) system conducts all sample tracking and liquid handling steps, and ABI PRISM 7900 HT (Applied Biosystems) is used to conduct real-time determination of the C(t) value when amplification of PCR products is first detected and accumulation of inhibitory PCR products is unlikely to occur. The ABI PRISM 7900 HT Sequence Detection System features a real-time PCR instrument with 384-well-plate compatibility and robotic loading, and continuous wavelength detection, which enables the use of multiple fluorophores in a single reaction. The Allegro System offers an assembly line approach with a modular design that allows reconfiguration of the components to accommodate variations in the assay flow. In the present study, we have established and validated a new automated High Throughput (HT) TaqMan RT-PCR- based method for quantitative mRNA expression analysis. The data demonstrate that HT-Taqman PCR is a powerful tool that can be used for measuring low concentrations of mRNA, and is highly accurate, reproducible, and amenable to high throughput analysis. Results suggest that HT-TaqMan is a reliable method for the quantification of low-expression genes and a powerful tool with HT capability for target identification/validation, structure-activity relationship (SAR) study, compound selection for efficacy studies, and biomarker identification in drug discovery and development.  相似文献   
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The phase equilibrium in a system of linear polydimethylsiloxane–functionalized nanoparticles 1.2–2.2 nm in size with a core made of hyperbranched silica and a periphery of decyl groups has been studied by laser interferometry method. Phase diagrams of the studied systems fit the amorphous phase equilibrium with UCST increasing with the nanoparticle size. The mixtures present nanoparticle solutions in the linear polymer or emulsions of a saturated solution of one component in a saturated solution of other component depending on the components ratio. Dilute, concentrated, or highly concentrated dispersions show individual features of the rheological behavior. For each colloid chemical and phase states of mixtures, the viscosity and viscoelastic properties have been investigated in a wide temperature range. The obtained results have been compared with the previous data for mixtures of decylated nanoparticles and polyisobutylene.  相似文献   
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