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61.
Thermal, structural and optical properties of Nd3+ ions in tellurite glass (TeO2-ZnO-Na2O-Li2O-Nb2O5) have been investigated. Differential thermal analysis revealed reasonably good forming tendency of the glass composition. FTIR spectra were used to analyze the functional groups present in the glass. Judd-Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime, branching ratio and stimulated emission cross-section of the 4F3/2→4I9/2, 11/2, 13/2 transitions. The quantum efficiency of the 4F3/2 level is comparable as well as higher than the typical value of the other tellurite based glasses. The decay from the 4F3/2 level is found to be single exponential for different concentrations of Nd3+ ions with a shortening of lifetime with increasing concentration. The experimental values of branching ratio and saturation intensity of 4F3/2→4I11/2 transition indicate the favourable lasing action with low threshold power. 相似文献
62.
A. Akindinov A. Alici P. Antonioli S. Arcelli M. Basile F. Bellini D. Caffarri G. Cara Romeo L. Cifarelli F. Cindolo A. De Caro D. De Gruttola S. De Pasquale K. Doroud M. Fusco Girard B. Guerzoni D. Hatzifotiadou W. W. Jung D. W. Kim J. S. Kim S. Kiselev G. Laurenti K. Lee S. C. Lee D. Malkevich A. Margotti R. Nania A. Nedosekin F. Noferini P. Pagano A. Pesci O. Pinazza R. Preghenella M. Ryabinin E. Scapparone G. Scioli J. Seo A. Silenzi K. Voloshin M. C. S. Williams C. Zampolli A. Zichichi 《The European Physical Journal C - Particles and Fields》2010,68(3-4):601-607
The Time-Of-Flight detector (TOF) of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs). The TOF detector consists of 152928 readout channels covering a total area of 141 m2. In this paper the results of the calibration with cosmic-ray data collected during 2009 are presented. 相似文献
63.
Yong Suk Choi Jong-Yun Kim Suk Bon Yoon Kyuseok Song Young Jin Kim 《Microchemical Journal》2011,99(2):332-338
A wavelength-dispersive X-ray fluorescence (WDXRF) technique that uses the scattered radiation of the X-ray tube lines and the fluorescence radiation of an element present in a powder sample is proposed as a non-destructive method for the determination of the water content in silica powder. Although direct X-ray fluorescence analysis of water using WDXRF is not adequate for the quantitative determination of water in powder, due to the very low fluorescence yield for hydrogen and oxygen, the fluorescence signal of silicon (Si) in silica powder is attenuated by water, and is shown to decrease in proportion to the water content in silica powder. In addition, it is demonstrated that the Compton- and Rayleigh-scattering of the X-ray tube lines is proportional to the water content. The coefficients of determination, R2, of the linear regression equations obtained from the calibration curves for all individual scattered radiations and for the fluorescence radiation of Si were > 0.90. The sum of the peak intensities of the four scattering signals, i.e. the Rayleigh-scattered Rh K–L2,3 and Rh K–M2,3 lines, and Compton-scattered Rh K–L2,3 and Rh K–M2,3 lines, also showed fairly good linearity and sensitivity over a very wide range of water content from 0 wt.% to 61.5 wt.%. However, porosity had a significant effect on the X-ray signal at low water content, in the range from 0 wt.% to 7.5 wt.%, where the sensitivity for the silica nanopowder with well-defined mesopores (~ 3 nm in diameter) decreased to 0.40 kcps/wt.%, from 0.99 kcps/wt.% for the non-porous silica nanopowder. The use of the Si fluorescence signal along with the scattered radiation of the X-ray tube lines expands the applicability of conventional XRF spectrometers to the quantitative determination of water content in silica powder. 相似文献
64.
Heparin interacts with many proteins and is involved in biological processes such as anticoagulation, angiogenesis, and antitumorigenic activities. These heparin-protein interactions can be influenced by the binding of various metal ions to these complexes. In particular, physiologically relevant metal cations influence heparin-protein conformations through electronic interactions inherent to this polyanion. In this study, we employed ion mobility mass spectrometry (IMMS) to observe conformational changes that occur in fully-sulfated heparin octasaccharides after the successive addition of metal ions. Our results indicate that binding of positive counter ions causes a decrease in collision cross section (CCS) measurements, thus promoting a more compact octasaccharide structure. 相似文献
65.
Park In Ho G. Gnana Kumar A.R. Kim Pil Kim Kee Suk Nahm 《Bioelectrochemistry (Amsterdam, Netherlands)》2011,80(2):99-104
To evaluate a suitable electrode material for the efficient green energy generation of a bio-fuel cell, carbonaceous based carbon cloth, carbon paper, and carbon felt electrodes were investigated under different mediators. The larger surface area, low resistance, and open network of interwoven fibers of the carbon felt electrode facilitated higher electron transfer from the microbial organisms to the electrode surface than that of other carbonaceous electrodes. Carbon paper electrode exhibited lower fuel cell performances due to its lower roughness and high tortuous nature. The green power generation experiments were also carried out under different mediators such as 2-hydroxy-l,4-naphthoquinone and thionin. The electrons mitigation and power generation was augmented by 2-hydroxy-l,4-naphthoquinone than thionin due to its high solubility, stability, and minimal adsorption characteristic to the electrodes. By the combined efforts of extended electrons generation and transportation, bio-fuel cell performances were extended and endorsed its doable applications in bio-fuel cells. 相似文献
66.
Myoung Youp Song Mi Suk Shon Hye Ryoung Park 《Russian Journal of Electrochemistry》2011,47(12):1363-1367
In order to improve the cycling performance of LiMn2O4, a part of Mn in LiMn2O4 was replaced by Ni. LiNi
y
Mn2 − y
O4 (y = 0.02, 0.05, 0.10, 0.15, and 0.20) were synthesized by preheating a mixture of LiOH, MnO2 (CMD), and NiO at 400°C for 10 h and then calcining at 850°C for 48 h in air with intermediate grinding. The voltage vs.
discharge capacity curves at a current density of 300 μA/cm2 between 3.5 and 4.3 V showed two plateaus, but the plateaus became unclear as the value of y increased. The sample with y = 0.02 had the largest first discharge capacity of 118.1 mA h/g. The LiNi0.10Mn1.90O4 sample had a relatively large first discharge capacity of 95.0 mA h/g and snowed an excellent cycling performance. 相似文献
67.
Kyu-Oh Kim Yun-A Seo Byoung-Suhk Kim Kee-Jong Yoon Myung-Seob Khil Hak-Yong Kim Ick-Soo Kim 《Colloid and polymer science》2011,289(8):863-870
We report solution properties of the blend solutions of poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG)–POSS telechelic
and its corresponding hybrid nanofibers prepared by electrospinning. The morphologies, microstructures, and wettability of
the resulting PVA/PEG3.4k–POSS hybrid nanofibers are studied. The morphologies of the resultant PVA/PEG3.4k–POSS nanofibers
are regular with the fiber diameter ranging from 610 ± 110 to 810 ± 280 nm. When the content of PEG3.4k–POSS telechelic increases
above 20 wt.%, the beaded fiber morphologies are observed due to severe aggregations of the PEG3.4k–POSS telechelics as well
as increased viscosity at higher concentration. In addition, the solution properties of pure PEG3.4k–POSS telechelic solution
(ca. 3–5 wt.%) and PVA/PEG3.4k–POSS solutions blended with PVA are explored, and found to show the reversible turbid-to-transparent
transition behavior with respect to the solution temperature. Water contact angle measurement of the PVA/PEG3.4k–POSS nanofiber
membranes demonstrates an enhanced hydrophobic nature due to the incorporated POSS moieties. 相似文献
68.
The adsorption equilibrium and kinetics of single and binary component copper ions and phenol onto powdered activated carbon
(PAC), alginate beads and alginate-activated carbon beads (AAC) were studied. Adsorption equilibrium data for single component
copper ions and phenol onto the adsorbents could be represented by the Langmuir equation. Multicomponent equilibrium data
were correlated by the extended Langmuir and ideal adsorbed solution theory (IAST). The IAST gave the best fit to our data.
The amount of copper ions adsorbed onto the AAC beads in the binary component was greater than that of phenol. The internal
diffusion coefficients were determined by comparing the experimental concentration curves with those predicted from surface
diffusion and pore diffusion model. 相似文献
69.
Jihyeon Kim Jongkyoon Park Dr. Seonhwa Park Jeongwook Seo Jeongwook Kwon Hyunsoo Lee Prof. Dr. Seungchul Kim Prof. Dr. Haesik Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19364-19370
Distance-dependent electromagnetic radiation and electron transfer have been commonly employed in washing-free fluorescence and electrochemical bioassays, respectively. In this study, we combined the two distance-dependent phenomena for sensitive washing-free DNA detection. A distance-dependent surface plasmonic field induces rapid photoredox catalysis of surface-bound catalytic labels, and distance-dependent mediated electron transfer allows for rapid electron transfer from the surface-bound labels to the electrode. An optimal system consists of a chemically reversible acceptor (Ru(NH3)63+), a chemically reversible photoredox catalyst (eosin Y), and a chemically irreversible donor (triethanolamine). Side reactions with O2 do not significantly decrease the efficiency of photoredox catalysis. Energy transfer quenching between the electrode and the label can be lowered by increasing the distance between them. Washing-free DNA detection had a detection limit of approximately 0.3 nm in buffer and 0.4 nm in serum without a washing step. 相似文献
70.
Su-Gwang Jeong Junghoon Cha Sughwan Kim Jungki Seo Jeong-Hun Lee Sumin Kim 《Journal of Thermal Analysis and Calorimetry》2014,117(3):1027-1034
Epoxy resins are well-known materials that show beneficial properties, such as high tensile strength and modulus, good adhesive properties, low cost, and ease of processing and environmental advantages. However, epoxy resin adhesive has no characteristic of thermal storage. Latent heat storage is one of the favorable kinds of thermal energy storage methods considered for energy saving and thermal efficiency in various fields, such as solar air conditioning systems and buildings. So we prepared thermal-enhanced epoxy resin adhesive by using PCM. This paper addresses the effects of n-hexadecane and sodium lauryl sulfate on the thermal properties and chemical properties of epoxy resin adhesive and HEAC, using differential scanning calorimetry, thermal gravimetric analysis, and Fourier transform-infrared spectroscopy. Also, we evaluated the applicability of composite epoxy resin adhesive to wood-based flooring using n-hexadecane, through measurement of bonding strength from universal testing machine analysis. 相似文献