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991.
Epitaxial-Bain-Path and Uniaxial-Bain-Path studies reveal that a B2-CuZr nanowire with Zr atoms on the surface is energetically more stable compared to a B2-CuZr nanowire with Cu atoms on the surface. Nanowires of cross-sectional dimensions in the range of ~20–50 Å are considered. Such stability is also correlated with the initial state of stress in the nanowires. It is also demonstrated here that a more stable structure, i.e., B2-CuZr nanowire with Zr atoms at surface shows improved yield strength compared to B2-CuZr nanowire with Cu atoms at surface site, over range of temperature under both the tensile and the compressive loadings. Nearly 18% increase in the average yield strength under tensile loading and nearly 26% increase in the averaged yield strength under compressive loading are observed for nanowires with various cross-sectional dimensions and temperatures. It is also observed that the B2-CuZr nanowire with Cu atom at the surface site shows a decrease in failure/plastic strain with an increase in temperature. On the other hand, B2-CuZr nanowires with Zr at the surface site shows an improvement in failure/plastic strain, specially at higher temperature as compared to the B2-CuZr nanowires which are having Cu atoms at the surface site. Finally, a possible design methodology for an energetically stable nano-structure with improved thermo-mechanical properties via manipulating the surface atom configuration is proposed. 相似文献
992.
Some invariant solutions for non-conformal perfect fluid plates in 5-flat form in general relativity
A set of six invariant solutions for non-conformal perfect fluid plates in 5-flat form is obtained using one-parametric Lie
group of transformations. Out of the six solutions so obtained, three are in implicit form while the remaining three could
be expressed explicitly. Each solution describes an accelerating fluid distribution and is new as far as authors are aware. 相似文献
993.
994.
S. Meljanac A. Samsarov M. Stojić Kumar S. Gupta 《The European Physical Journal C - Particles and Fields》2008,53(2):295-309
We investigate a Lie algebra-type κ-deformed Minkowski spacetime with undeformed Lorentz algebra and mutually commutative
vector-like Dirac derivatives. There are infinitely many realizations of κ-Minkowski space. The coproduct and the star product
corresponding to each of them are found. An explicit connection between realizations and orderings is established and the
relation between the coproduct and the star product, provided through an exponential map, is proved. Utilizing the properties
of the natural realization, we construct a scalar field theory on κ-deformed Minkowski space and show that it is equivalent to the scalar,
nonlocal, relativistically invariant field theory on the ordinary Minkowski space. This result is universal and does not depend
on the realizations, i.e. the orderings, used. 相似文献
995.
Optics has already been proved as a successful candidate for conducting parallel logic, arithmetic and algebraic operations. Several all-optical data processors were proposed since last few decades. To implement these systems, different data encoding decoding techniques such as polarization encoding, tristate, quartenary state, multivalued state, symbolic substitution technique etc. have already been proposed. All these are done to use optics in a suitable platform. We propose here a new concept of encoding data by adopting frequencies variation technique for conducting a inversion operation successfully. 相似文献
996.
A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the overall burst loss in the network and at the same time to avoid the packet out-of-sequence arrival problem. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution schemes based on conventional routing. Through extensive simulations, it is shown that the proposed scheme not only provides significantly better burst loss performance than the basic equal proportion and hop-length based traffic routing algorithms, but also is void of any packet re-orderings. 相似文献
997.
To exploit the parallelism of optics in data processing,a suitable number system and an efficient encoding/decoding scheme for handling the data are very essential.In the field of optical computing and parallel information processing,several number systems like binary,quaternary,octal,hexadecimal,etc.have been used for different arithmetic and algebraic operations.Here,we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture. 相似文献
998.
H. E. Stanley P. Kumar G. Franzese L. Xu Z. Yan M. G. Mazza S. V. Buldyrev S.-H. Chen F. Mallamace 《The European physical journal. Special topics》2008,161(1):1-17
We present evidence from experiments and computer
simulations supporting the hypothesis that water displays
polyamorphism, i.e., water separates into two distinct liquid
phases. This concept of a new liquid-liquid phase transition is
finding application to other liquids as well as water, such as
silicon and silica. Specifically, we investigate, the relation
between changes in dynamic and thermodynamic anomalies arising from
the presence of the liquid-liquid critical point in (i) Two models
of water, TIP5P and ST2, which display a first order liquid-liquid
phase transition at low temperatures; (ii) the Jagla model, a
spherically symmetric two-scale potential known to possess a
liquid-liquid critical point, in which the competition between two
liquid structures is generated by repulsive and attractive ramp
interactions; and (iii) A Hamiltonian model of water where the idea
of two length/energy scales is built in. This model also displays a
first order liquid-liquid phase transition at low temperatures
besides the first order liquid-gas phase transition at high
temperatures. We find a correlation between the dynamic fragility
crossover and the locus of specific heat maxima CPmax
(“Widom line”) emanating from the critical point. Our findings are
consistent with a possible relation between the previously
hypothesised liquid-liquid phase transition and the transition in
the dynamics recently observed in neutron scattering experiments on
confined water. More generally, we argue that this connection
between CPmax and the dynamic crossover is not limited to
the case of water, a hydrogen bonded network liquid, but is a more
general feature of crossing the Widom line, an extension of the
first-order coexistence line in the supercritical region.
Dedicated to Armin Bunde on the occasion of his 60th birthday. 相似文献
999.
A novel optical burst switching (OBS) high speed network architecture has been proposed. To verify its feasibility and evaluate its performance, just-enough-time (JET) signaling has been considered as a high performance protocol. In the proposed architecture, to avoid burst losses, firstly, a short-prior- confirmation-packet (SPCP) is sent over the control channel that simulates the events that the actual packet will experience. Once SPCP detects a drop at any of the intermediate nodes, the actual packet is not sent but the process repeats. In order to increase network utilization, cost effectiveness and to overcome some limitations of conventional OBS, inherent codes (e.g., orthogonal optical codes (OOC)), which are codified only in intensity, has been used. Through simulations, it shows that a decrease in burst loss probability, cost effectiveness and a gain in processing time are obtained when optical label processing is used as compared with electronic processing. 相似文献
1000.
l-Glutamine amidohydrolase (l-glutaminase, EC 3.5.1.2) is a therapeutically and industrially important enzyme. Because it is a potent antileukemic agent
and a flavor-enhancing agent used in the food industry, many researchers have focused their attention on l-glutaminase. In this article, we report the continuous production of extracellular l-glutaminase by the marine fungus Beauveria bassiana BTMF S-10 in a packed-bed reactor. Parameters influencing bead production and performance under batch mode were optimized
in the order-support (Na-alginate) concentration, concentration of CaCl2 for bead preparation, curing time of beads, spore inoculum concentration, activation time, initial pH of enzyme production
medium, temperature of incubation, and retention time. Parameters optimized under batch mode for l-glutaminase production were incorporated into the continuous production studies. Beads with 12×108 spores/g of beads were activated in a solution of 1% glutamine in seawater for 15 h, and the activated beads were packed
into a packed-bed reactor. Enzyme production medium (pH 9.0) was pumped through the bed, and the effluent was collected from
the top of the column. The effect of flow rate of the medium, substrate concentration, aeration, and bed height on continuous
production of l-glutaminase was studied. Production was monitored for 5 h in each case, and the volumetric productivity was calculated. Under
the optimized conditions for continuous production, the reactor gave a volumetric productivity of 4.048 U/(mL·h), which indicates
that continuous production of the enzyme by Ca-alginate-immobilized spores is well suited for B. bassiana and results in a higher yield of enzyme within a shorter time. The results indicate the scope of utilizing immobilized B. bassiana for continuous commercial production of l-glutaminase. 相似文献