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961.
E. T. Knypl 《Isotopes in environmental and health studies》2013,49(5):190-192
Investigations on efficiency of refining of acetic acid by normal freezing method with radiotracer technique and neutron activation are presented. Equilibrium distribution coefficient for Zn2+ in CH3COOH was determined; the same coefficient was also determined for Cl? but with lower degree of approximation and a “generalized” distribution coefficient for a set of ions was estimated by comparison of radioactivity of original and refined samples of acetic acid after neutron activation in nuclear reactor. 相似文献
962.
963.
The isothermal section of the phase diagram of the Tb–Co–Cr ternary system at 873?K was investigated by means of X-ray diffraction, metallography, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. Ternary phases and their lattice parameters as a function of composition of solid solution were systematically studied. The existence of one ternary phase reported previously was confirmed. The ternary compound Tb(Co,?Cr)12 crystallizes with ThMn12-type structure, space group I4/mmm. The linear homogeneity range along the line of 7.69 at.% Tb in TbCo12? x Cr x was found to be about x?=?3.6–5.7, i.e., 27.7–43.8 at.% Cr. The lattice parameters are a?=?0.8326–0.8352?nm and c?=?0.4709–0.4740?nm. The maximum solid solubilities of Cr in Tb2Co17, TbCo3, and TbCo2 are about 20.0, 8.2, and 7.9 at.%, respectively. 相似文献
964.
Cobalt (Co) addition and thermal annealing induced structural and vibrational properties of ZnO nanostructures were analysed. X‐ray diffraction pattern reveals that the nanostructures are in hexagonal wurtzite type and the formation of Co3O4. The Co ion induced morphology changes have been studied by high‐resolution scanning electron microscope images and energy dispersive spectroscopy measurements confirm the presence of Co ions. CoO‐related magnon excitation bands are emerged at room temperature for the Co‐added samples. There are no changes in the band positions of the Raman spectra of pure and Co‐added materials. Annealed sample exhibits the suppression of magnon bands and formation of Co3O4: ZnO composites. Raman line width and the electron phonon coupling constant are decreased with respect to the annealing temperature. The formation of Co3O4 : ZnO composite phases have further confirmed by infrared spectra. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
965.
为明确深亚微米NMOS器件抗辐照能力以及研究其加固措施, 本文对0.18 μm窄沟NMOS晶体管进行了60Coγ总剂量辐射效应研究. 结果表明: 和宽沟器件不同, 阈值电压、跨导、漏源电导对总剂量辐照敏感, 此现象被称之为辐射感生窄沟道效应; 相比较栅氧化层, 器件隔离氧化层对总剂量辐照更敏感; 窄沟道NMOS器件阈值电压不仅和沟道耗尽区电荷有关, 寄生晶体管耗尽区电荷对其影响也不可忽略, 而辐照引起源漏之间寄生晶体管开启, 形成漏电通道, 正是导致漏电流、亚阈斜率等参数变化的原因.
关键词:
0.18μmm
窄沟NMOS晶体管
60Coγ辐照')" href="#">60Coγ辐照
辐射感生窄沟道效应 相似文献
966.
Titanium silicalite (TS) and TiO2 nanocomposites were prepared by mixing TS and TiO2 with different ratios in ethanol. They were impregnated with 15 wt% Co loading to afford Co‐based catalysts. Fischer–Tropsch synthesis (FTS) performance of these TS–TiO2 nanocomposite‐supported Co‐based catalysts was studied in a fixed‐bed tubular reactor. The results reveal that the Co/TS–TiO2 catalysts have better catalytic performance than Co/TS or Co/TiO2 each with a single support, showing the synergistic effect of the binary TS–TiO2 support. Among the TS–TiO2 nanocomposite‐supported Co‐based catalysts, Co/TS–TiO2‐1 presents the highest activity. These catalysts were characterized using N2 adsorption–desorption measurements, X‐ray diffraction, X‐ray photoelectron spectroscopy, H2 temperature‐programmed reduction, H2 temperature‐programmed desorption and transmission electron microscopy. It was found that the position of the active component has a significant effect on the catalytic activity. In the TS–TiO2 nanocomposites, cobalt oxides located at the new pores developed between TS and TiO2 can exhibit better catalytic activity. Also, a positive relationship is observed between Co dispersion and FTS catalytic performance for all catalysts. The catalytic activity is improved on increasing the dispersion of Co. 相似文献
967.
Gamma photon induced modifications in Polyvinylchloride (PVC) polymer have been studied in the dose range of 101-106Gy at room temperature. Polyvinylchloride films have been irradiated with different doses of gamma radiation from a 60Co source. To monitor the chemical and structural changes caused by gamma radiation IR and UV-Vis spectroscopy of pristine and irradiated PVC have been performed and using the spectral data some changes in the properties have been investigated. The spectral studies have indicated that at a dose of 106Gy scissioning of the C-a bonds takes place. This scissioning of the chain initiates decomposition at a lower temperature. Thermal stability of the polymer reduces due to irradiation but the decomposition patterns remain the same. The optical band-gap is found to decrease due to irradiation at doses bigher than 103Gy. 相似文献
968.
《Physics and Chemistry of Liquids》2012,50(2):200-206
The electrical conductivity and thermoelectric power of liquid Co–Sn alloys were investigated in a wide concentration and temperature range. It was shown that the electrical conductivity of the melts decreased with an increase of the Co content. The results are interpreted in the context of the s–d hybridisation model. The corresponding behaviour is caused by sharing electrons from one metal to another one. This is in agreement with the concept of Fermi enthalpy, according to which up to two electrons from Sn transfer to the uppermost bands of Co. 相似文献
969.
Bushra Iqbal Dr. Murtaza Saleem Dr. Salman Noshear Arshad Dr. Jamshaid Rashid Dr. Naveed Hussain Dr. Muhammad Zaheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(44):10490-10498
A one-pot synthesis of bimetallic metal–organic frameworks (Co/Fe-MOFs) was achieved by treating stoichiometric amounts of Fe and Co salts with 2-aminoterephthalic acid (NH2-BDC). Monometallic Fe (catalyst A) and Co (catalyst F) were also prepared along with mixed-metal Fe/Co catalysts (B–E) by changing the Fe/Co ratio. For mixed-metal catalysts (B–E) SEM energy-dispersive X-ray (EDX) analysis confirmed the incorporation of both Fe and Co in the catalysts. However, a spindle-shaped morphology, typically known for the Fe-MIL-88B structure and confirmed by PXRD analysis, was only observed for catalysts A–D. To test the catalytic potential of mixed-metal MOFs, reduction of nitroarenes was selected as a benchmark reaction. Incorporation of Co enhanced the activity of the catalysts compared with the parent NH2-BDC-Fe catalyst. These MOFs were also tested as electrocatalysts for the oxygen evolution reaction (OER) and the best activity was exhibited by mixed-metal Fe/Co-MOF (Fe/Co batch ratio=1). The catalyst provided a current density of 10 mA cm−2 at 410 mV overpotential, which is comparable to the benchmark OER catalyst (i.e., RuO2). Moreover, it showed long-term stability in 1 m KOH. In a third catalytic test, dehydrogenation of sodium borohydride showed high activity (turnover frequency=87 min−1) and hydrogen generation rate (67 L min−1 g−1 catalyst). This is the first example of the synthesis of bimetallic MOFs as multifunctional catalysts particularly for catalytic reduction of nitroarenes and dehydrogenation reactions. 相似文献
970.