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排序方式: 共有391条查询结果,搜索用时 31 毫秒
31.
Study on phenol adsorption from aqueous solutions on exfoliated graphitic nanoplatelets 总被引:1,自引:0,他引:1
Alina C. Ion Alla AlpatovaI. Ion Alina Culetu 《Materials Science and Engineering: B》2011,176(7):588-595
In this study we report first data on exfoliated graphitic nanoplatelets (xGnPs) as a sorbent for phenol removal and preliminary evaluated the ability of different type of natural organic matter (NOM) to effectively disperse exfoliated graphitic nanoplatelets. 相似文献
32.
Sergey Sigalov Mikhael D. Levi Gregory Salitra Doron Aurbach Alar Jänes Enn Lust Ion C. Halalay 《Carbon》2012,50(10):3957-3960
A TiC-derived carbon (TiC-CDC) was prepared, and the adsorption of large hexacyanocobaltate and tetrabutylammonium ions of approximately same size was examined on this carbon. While selectively absorbing these large ions, it rejects smaller chloride and ammonium ions in mixed electrolyte solutions. The result demonstrates the important role of electrostatic repulsive forces, space-efficient charge packing and hydrophobic ion interactions with the pore walls of TiC-CDC, similar to what is known for a variety of biological membranes. 相似文献
33.
M.J. Anderson K. McGuire R.C. Zante W.J. Ion A. Rosochowski J.W. Brooks 《Journal of Materials Processing Technology》2013,213(1):111-119
The dies used in the extrusion of nickel based super alloys are subject to severe mechanical and thermal stresses, resulting in shortened life and high manufacturing costs. It is necessary to understand the dominant damage mode in order to guide improvements for increased tool life. The operation under examination consists of the hot extrusion of a nickel based superalloy using nitrided hot work tool steel, glassed workpieces and graphite lubrication. The investigation was conducted through a combination of metallurgical analysis, metrology and finite element analysis. Out of the damage modes observed under these conditions, the plastic deformation of the substrate was found to be the cause for tool failure. This paper discusses the relationship between plastic deformation of the substrate and the formation of scoring marks, which fail the die. 相似文献
34.
Zinc phthalocyanine dyes, which had been symmetrically and asymmetrically substituted with sulfonate groups were investigated using absorption, fluorescence and photoacoustic spectroscopic methods, supported by light-induced optoacoustic spectroscopy and photoelectric measurements; unsubstituted zinc phthalocyanine was employed as reference. Fluorescence quantum yields were determined on the basis of absorption and fluorescence spectra, whereas thermal parameters as well as the yield of triplet state population and the kinetics of thermal relaxation at microsecond intervals were determined using with photoacoustic methods. The effect of the sulfonate groups on photocurrent generation was discussed in terms of the dye's molecular structure and resonance (mesomeric, inductive, steric) effects. Sulfonation of zinc phthalocyanine changed markedly its absorption and fluorescence properties owing to redistribution of the electron density within the molecule as a result of both mesomeric and inductive effects, although other effects cannot be excluded. The enhanced light-generated photocurrent observed for phthalocyanine with two sulfonate groups is explained in terms of mesomeric effects, whereas in phthalocyanine with three and four sulfonate groups, inductive effects are essential and lead to photocurrent decline. 相似文献
35.
Inculet Ion I. Hodgson Kenneth J. Millward James G. 《Industry Applications, IEEE Transactions on》1986,(6):977-981
Experimental results of a novel method and apparatus for achieving selective deposition on the inside surfaces of an enclosure are presented. An apparatus consisting of two aerodynamically shaped air shear nozzlesa generated a charged dual cloud comprising an insecticide aerosol cloud above and a water aerosol cloud below. Through self-expansion of the cloud by mutual repulsion of the charged particles and image attraction to the wall surfaces, a significantly selective deposition was achieved on the inside surfaces in the upper and lower halves of the enclosure. 相似文献
36.
Marek Karpinski Ion I. Mandoiu Alexander Olshevsky Alexander Zelikovsky 《Algorithmica》2005,42(2):109-120
The Quality of Service Multicast Tree Problem is a generalization of
the Steiner tree problem which appears in the context of multimedia
multicast and network design. In this generalization, each node
possesses a rate and the cost of an edge with length l in a
Steiner tree T connecting the source to non-zero rate nodes is l
· re, where re is the maximum node rate in the component of
T-{e} that does not contain the source. The best previously
known approximation ratios for this problem (based on the best known
approximation factor of 1.549 for the Steiner tree problem in
networks) are 2.066 for the case of two non-zero rates and 4.212 for
the case of an unbounded number of rates. In this paper we give
improved approximation algorithms with ratios of 1.960 and 3.802,
respectively. When the minimum spanning tree heuristic is used for
finding approximate Steiner trees, then the previously best known
approximation ratios of 2.667 for two non-zero rates and 5.542 for an
unbounded number of rates are reduced to 2.414 and 4.311,
respectively. 相似文献
37.
38.
北京大学6MV串列静电加速器上建成4条束流输运线,加速^1H,^12C,^16O,^19F,^35Cl,^79Br等离子,并开展物理实验研究。首次利用D(^12C,p)^13C核反应建立起高灵敏度的氘分析法;利用共振核反应^1H(^19F,αγ)^16O分析材料中氢的深度分布;用重离子背散射分析超导材料YBa2Cu3O7-x;用35MeV^35Cl和45MeV^79Br的弹性前冲分析不同材料中的轻 相似文献
39.
Using the fact that the Parikh matrix mapping is not an injective mapping, the paper investigates some properties of the set of words with the same Parikh matrix; these words are called “amiable”. The presented results extend the results obtained in [A. Atanasiu, Binary amiable words, Int. J. Found. Comput. Sci. 18 (2) (2007) 387–400] for the binary case. In particular it is shown that all the words having the same Parikh matrix can be obtained one from another by applying only two types of transformations. Moreover, the mirrors of two amiable words are also amiable (thus forming a symmetrical class of words). 相似文献
40.
Takami Kai Norihide Okada Manabu Baba Takeshige Takahashi Masaki Misawa Ion Tiseanu Naoki Ichikawa 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2007,130(2-3):119-124
In a fluidized catalyst bed, the reactant gas transfers from the bubble phase to the emulsion phase and reactions proceed in the emulsion phase. The catalyst particles around the bubbles should contact the gases containing a high concentration of the reactants. Therefore, the effect of the catalysts around the bubbles is very important for estimating the conversion and selectivity in the reactor. In order to study the role of these catalysts, the hydrogenation of carbon dioxide was carried out in a fluidized catalyst bed. Based on the results, the amount of the catalyst that was effective for the reaction was calculated. In addition, the shape of the bubbles ascending in the fluidized catalyst bed was observed using a fast X-ray computer tomography (CT) scanner. The structure of the bubbles in the fluidized catalyst bed was very complicated and the surface area of the bubbles was much greater than the obtained when assuming spherical shaped bubble. By assuming that effective catalysts existed around the bubbles, the thickness of catalyst layer was obtained. Finally, the 3-dimensional images of the catalyst layers around the bubbles were reconstructed. 相似文献