《Zeolites》1987,7(3):235-239

  相似文献   

    

《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1987,257(2):189-196

We describe progress in the Tohoku neutron time-of-flight (TOF) facilities improved to facilitate high resolution measurements for neutrons in the range 10 ≤ E_n ≲ 60 MeV. Efforts have been concentrated on completing the neutron detection system consisting of twelve neutron detectors, in which 23 1 of NE213 liquid scintillator are encapsulated, and a CAMAC-based data acquisition system. A systematic study of the neutron detection efficiency has been performed by Monte Carlo calculation for monochromatic neutrons with E_n ≲ 34 MeV. Results have been tested by counting neutrons from the ⁷Li(p, n)⁷Be reaction and comparing the yield with the absolute neutron fluence determined by activation.  相似文献   

    

《Thin solid films》1987,151(1):41-50

Marker experiments have been used to study the formation and the oxidation of two semiconducting silicides with large band gaps. Both Ru₂Si₃ and Ir₃Si₅ have been shown to form by mechanisms dominated by the motion of the silicon atoms. The same is true for the growth of SiO₂ over these two silicides under conditions which ensure the integrity of the silicide layers. IrSi has also been shown to grow mostly through the motion of silicon.  相似文献   

    

《Zeolites》1987,7(4):295-300

Cobalt-ZSM-5 is prepared by addition of various cobalt containing substrates to ZSM-5 synthesis gels. The existence and homogeneity of intrazeolitic cobalt is established from XPS and electron microprobe analyses. Variations in the synthesis gel composition were found to influence the amount of intrazeolitic cobalt in the ZSM-5. In at least one preparation, the ion exchange data are consistent with cobalt occupying framework sites. Cobalt-ZSM-5 exposure to 3 atm. H₂ at 470°C and 21 atm. rsol|CO/H₂ (1:1) at temperatures to 470°C did not reduce the cobalt to the zero-valent state and did not cause the cobalt to migrate to the outer surface of the ZSM-5.  相似文献   

    

《Materials Chemistry and Physics》1987,17(5):453-460

This study is devoted to the mechanical properties of asbestos-epoxy composites. Chrysotile fibres were first pretreated by means of an interfacial polymerization technique effecting eventually a poly (hexamethylene adipamide) coating on the asbestos surface. The interface characteristics were significantly altered and due to the well-known compatibility between epoxy and polyamide phase considerable deviation from the behaviour encountered when using untreated fibres was confirmed. Accordingly, while varying pretreated fibre content and also concentration of the polyamide coating, the tensile properties of the resulted composites were examined.  相似文献   

    

《Smart Materials Bulletin》2002,2002(5):16

Dr Shuji Nakamura, famous in the materials world for his successful development of the blue LED, has had his immediate career and the future prospects for gallium nitride welded together through a $l6m, five-year grant from Japan's Science and Technology Corporation.  相似文献   

    

《International Journal of Inorganic Materials》1999,1(3-4):253-258

HTaWO₆/(Pt,TiO₂) and HTaWO₆/(Pt,Fe₂O₃) nanocomposites were synthesized by successive intercalation reactions of HTaWO₆ with [Pt(NH₃)₄]Cl₂ aqueous solution, n-C₃H₇NH₂/n-heptane mixed solution and acidic TiO₂ colloid solution or [Fe₃(CH₃CO₂)₇(OH)(H₂O)₂]NO₃ aqueous solution followed by UV light irradiation. The gallery heights of HTaWO₆/(Pt,TiO₂), HTaWO₆/TiO₂, HTaWO₆/(Pt,Fe₂O₃) and HTaWO₆/Fe₂O₃ was less than 0.51 nm. The host HTaWO₆ was white possessing band gap energy of 3.1 eV, whereas HTaWO₆/Pt, HTaWO₆/(Pt,TiO₂), HTaWO₆/Fe₂O₃ and HTaWO₆/(Pt,Fe₂O₃) were yellow and showed broad reflection over 400–600 nm together with that corresponding to the host layer. Photocatalytic activities of HTaWO₆/TiO₂ and HTaWO₆/Fe₂O₃ were superior to those of unsupported TiO₂ and Fe₂O₃ and were greatly enhanced by co-incorporation of Pt. HTaWO₆/Pt, HTaWO₆/(Pt,TiO₂), HTaWO₆/Fe₂O₃ and HTaWO₆/(Pt,Fe₂O₃) showed photocatalytic activity.  相似文献   

    

《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2003,496(2-3):239-247

  相似文献   

    

《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2003,496(2-3):293-304

Radiation-hard ionization chambers were tested using an intense electron beam from the accelerator test facility at the Brookhaven National Laboratory. The detectors were designed to be used as the basic element for monitoring muons in the Main Injector Neutrino beamline at the Fermi National Accelerator Laboratory. Measurements of linearity of response, voltage dependence, and the onset of ionization saturation as a function of gap voltage were performed.  相似文献   

    

《Materials Chemistry and Physics》2001,67(1-3):43-48

In this work we present the application to a T15 high speed steel of a modified metal injection moulding process based on the use of a thermosetting resin. This method has been successfully applied to produce 316L stainless steels and M2 HSS. The main characteristic of this manufacturing method is that the slurry (polymer and metal powder) is introduced into the mould at room temperature and afterward is heated at 90°C in order to polymerise the resin. We have optimised the powder-binder formulation and the best thermal debinding cycle by means of thermogravimetric analysis. Since the microstructure and properties of the HSS is very sensitive to the sintering temperature, its effect on the density, hardness, transverse rupture strength and microstructure was investigated. The mechanical properties obtained are in good agreement with other HSS parts manufactured by conventional MIM. During the sintering process it has been identified vanadium carbide (MC) and tungsten carbide (M₆C) that are homogeneously distributed on the steel matrix.  相似文献