773 research outputs found

    High LO-RF isolation of zero-IF mixer in 0.18 mu m CMOS technology

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    In this study, we introduce a zero-IF sub-harmonic mixer with high isolation in the 5 GHz band using 0.18 mu m CMOS technology. Placing an LC-Tank between the class AB stage and the mixer core improves the isolation between the LO to RF at low supply voltage. The measured isolation is 48 dB between the LO and RF ports, and the 9.5 dB conversion gain is achieved with a supply voltage of 7 mA at 2.5 V. In order to alleviate the degradation of linearity due to the high conversion gain, we adopt the class AB stage as RF input stage. The measured IIP3 is -7.5 dBm

    High-level expression of Trigonopsis variabilis D-amino acid oxidase in Escherichia coli using lactose as inducer

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    The use of lactose as inducer for the expression of Trigonopsis variabilis D-amino acid oxidase gene (daao) was investigated in Escherichia coli regulated by T7 or T5 promoter. The daao gene was prepared by reverse transcriptase-polymerase chain reaction and cloned into pET21b and pQE-30 to yield pET-DAAO and pQE-DAAO, respectively. The His(6)-tagged DAAO was expressed in E. coli and had a M-r value of approximately 39.3 kDa. In lactose-induced E. coli BL21 (DE3) (pET-DAAO), the expressed DAAO could comprise up to 15% of total soluble proteins and a productivity of 23.4 U ml(-1) was obtained

    Application of simulation technique on debris flow hazard zone delineation: a case study in the Daniao tribe, Eastern Taiwan

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    Typhoon Morakot struck Taiwan in August 2009 and induced considerable disasters, including large-scale landslides and debris flows. One of these debris flows was experienced by the Daniao tribe in Taitung, Eastern Taiwan. The volume was in excess of 500 000 m(3), which was substantially larger than the original design mitigation capacity. This study considered large-scale debris flow simulations in various volumes at the same area by using the DEBRIS-2D numerical program. The program uses the generalized Julien and Lan (1991) rheological model to simulate debris flows. In this paper, the sensitivity factor considered on the debris flow spreading is the amount of the debris flow initial volume. These simulated results in various amounts of debris flow initial volume demonstrated that maximal depths of debris flows were almost deposited in the same area, and also revealed that a 20% variation in estimating the amount of total volume at this particular site results in a 2.75% variation on the final front position. Because of the limited watershed terrain, the hazard zones of debris flows were not expanded. Therefore, the amount of the debris flow initial volume was not sensitive

    Early stage morphology of quench condensed Ag, Pb and Pb/Ag hybrid films

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    Scanning Tunneling Microscopy (STM) has been used to study the morphology of Ag, Pb and Pb/Ag bilayer films fabricated by quench condensation of the elements onto cold (T=77K), inert and atomically flat Highly Oriented Pyrolytic Graphite (HOPG) substrates. All films are thinner than 10 nm and show a granular structure that is consistent with earlier studies of QC films. The average lateral diameter, 2rˉ\bar {2r}, of the Ag grains, however, depends on whether the Ag is deposited directly on HOPG (2rˉ\bar {2r} = 13 nm) or on a Pb film consisting of a single layer of Pb grains (2rˉ\bar {2r} = 26.8 nm). In addition, the critical thickness for electrical conduction (dGd_{G}) of Pb/Ag films on inert glass substrates is substantially larger than for pure Ag films. These results are evidence that the structure of the underlying substrate exerts an influence on the size of the grains in QC films. We propose a qualitative explanation for this previously unencountered phenomenon.Comment: 11 pages, 3 figures and one tabl

    Interacting entropy-corrected holographic dark energy with apparent horizon as an infrared cutoff

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    In this work we consider the entropy-corrected version of interacting holographic dark energy (HDE), in the non-flat universe enclosed by apparent horizon. Two corrections of entropy so-called logarithmic 'LEC' and power-law 'PLEC' in HDE model with apparent horizon as an IR-cutoff are studied. The ratio of dark matter to dark energy densities uu, equation of state parameter wDw_D and deceleration parameter qq are obtained. We show that the cosmic coincidence is satisfied for both interacting models. By studying the effect of interaction in EoS parameter, we see that the phantom divide may be crossed and also find that the interacting models can drive an acceleration expansion at the present and future, while in non-interacting case, this expansion can happen only at the early time. The graphs of deceleration parameter for interacting models, show that the present acceleration expansion is preceded by a sufficiently long period deceleration at past. Moreover, the thermodynamical interpretation of interaction between LECHDE and dark matter is described. We obtain a relation between the interaction term of dark components and thermal fluctuation in a non-flat universe, bounded by the apparent horizon. In limiting case, for ordinary HDE, the relation of interaction term versus thermal fluctuation is also calculated.Comment: 20 pages, 8 figures, figures changed, some Ref. is added, changed some sentences, accepted by General relativity and gravitation (GERG

    Full counting statistics of information content

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    We review connections between the cumulant generating function of full counting statistics of particle number and the R\'enyi entanglement entropy. We calculate these quantities based on the fermionic and bosonic path-integral defined on multiple Keldysh contours. We relate the R\'enyi entropy with the information generating function, from which the probability distribution function of self-information is obtained in the nonequilibrium steady state. By exploiting the distribution, we analyze the information content carried by a single bosonic particle through a narrow-band quantum communication channel. The ratio of the self-information content to the number of bosons fluctuates. For a small boson occupation number, the average and the fluctuation of the ratio are enhanced.Comment: 16 pages, 5 figure

    The generalized second law of thermodynamics of the universe bounded by the event horizon and modified gravity theories

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    In this paper, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon. Here we consider homogeneous and isotropic model of the universe filled with perfect fluid in one case and in another case holographic model of the universe has been considered. In the third case the matter in the universe is taken in the form of non-interacting two fluid system as holographic dark energy and dust. Here we study the above cases in the Modified gravity, f(R) gravity.Comment: 9 page

    The beam energy measurement system for the Beijing electron-positron collider

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    The beam energy measurement system (BEMS) for the upgraded Beijing electron-positron collider BEPC-II is described. The system is based on measuring the energies of Compton back-scattered photons. The relative systematic uncertainty of the electron and positron beam energy determination is estimated as 2 \cdot 10^{-5}. The relative uncertainty of the beam's energy spread is about 6 %

    Statefinder Parameters for Different Dark Energy Models with Variable G Correction in Kaluza-Klein Cosmology

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    In this work, we have calculated the deceleration parameter, statefinder parameters and EoS parameters for different dark energy models with variable GG correction in homogeneous, isotropic and non-flat universe for Kaluza-Klein Cosmology. The statefinder parameters have been obtained in terms of some observable parameters like dimensionless density parameter, EoS parameter and Hubble parameter for holographic dark energy, new agegraphic dark energy and generalized Chaplygin gas models.Comment: 9 pages, no figure, accepted for publication in IJTP. arXiv admin note: text overlap with arXiv:1104.2366 by other author
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