601 research outputs found
Optimal entanglement purifying via entanglement swapping
It is known that entanglement swapping can be used to realize entanglement
purifying. By this way, two particles belong to different non-maximally
entangled pairs can be projected probabilisticly to a maximally entangled state
or to a less entangled state. In this report, we show, when the less entangled
state is obtained, if a unitary transformation is introduced locally, then a
maximally entangled state can be obtained probabilisticly from this less
entangled state. The total successful probability of our scheme is equal to the
entanglement of a single pairpurification (if two original pairs are in the
same non-maximally entangled states) or to the smaller entanglement of a single
pair purification of these two pairs (if two original pairs are not in the same
non-maximally entangled states). The advantage of our scheme is no continuous
indefinite iterative procedure is needed to achieve optimal purifying.Comment: 7 pages, Revtex, no figure, accepted by Phys. Rev. A as a Brief
Repor
Transmission electron microscopy evidence for phase transformation from Bi2Sr2CuO6 to Bi2Sr2Ca2Cu3O10
he growth mechanism of the Bi-2223 phase was studied using multifilamentary Ag/Bi-2223 tapes manufactured by the powder-in-tube method. X-ray powder diffraction was performed to analyze the developments of Bi-2201, Bi-2212, and Bi-2223 phases during sintering periods at high temperatures. Transmission electron microscopy (TEM) was used to investigate the growth mechanism of the 2223 phase. TEM images indicated that 2201 and Ca2CuO3 crystals come together to form platelets of 2223. The structural phase transformation established a structural frame of the 2223 crystal. There were some vacant defects retaining in the established 2223 crystal cells at copper and oxygen sites after the phase transformation, and the Cu/O compound at high temperatures would diffuse into 2223 cells and occupy the corresponding vacancies to complete the 2223 crystal structure. The present work provides an evidence for growing the 2223 phase from the 2201 phase and Ca2CuO3 in the samples studied
Zinc deficiency activates S100A8 inflammation in the absence of COX-2 and promotes murine oral-esophageal tumor progression
Zinc (Zn)-deficiency (ZD) is implicated in the pathogenesis of human oral-esophageal cancers. Previously, we showed that in ZD mice genetic deletion of cyclooxygenase-2 (Cox-2) enhances N-nitrosomethylbenzylamine-induced forestomach carcinogenesis. By contrast, Cox-2 deletion offers protection in Zn-sufficient (ZS) mice. We hypothesize that ZD activates pathways insensitive to COX-2 inhibition, thereby promoting carcinogenesis. This hypothesis is tested in a Cox-2−/− mouse tongue cancer model that mimics pharmacologic blockade of COX-2 by firstly examining transcriptome profiles of forestomach mucosa from Cox-2−/− and wild-type mice on a ZD vs. ZS diet, and secondly investigating the roles of identified markers in mouse forestomach/tongue preneoplasia and carcinomas. In Cox-2−/− mice exposed to the tongue carcinogen 4-nitroquinoline 1-oxide, dietary ZD elicited tongue/esophagus/forestomach carcinomas that were prevented by ZS. The precancerous ZD:Cox-2−/−vs. ZS:Cox-2−/− forestomach had an inflammatory signature with upregulation of the proinflammation genes S100a8 and S100a9. Bioinformatics analysis revealed overrepresentation of inflammation processes comprising S100a8/a9 and an nuclear factor (NF)-κB network with connectivity to S100A8. Immunohistochemistry revealed co-overexpression of S100A8, its heterodimeric partner S100A9, the receptor for advanced glycation end-products (RAGE), NF-κB p65, and cyclin D1, in ZD:Cox-2−/− forestomach/tongue preneoplasia and carcinomas, evidence for the activation of a RAGE-S100A8/A9 inflammatory pathway. Accumulation of p53 in these carcinomas indicated activation of additional inflammatory pathways. Zn-replenishment in ZD:Cox-2−/−mice reversed the inflammation and inhibited carcinogenesis. Thus, ZD activates alternative inflammation-associated cancer pathways that fuel tumor progression and bypass the antitumor effect of Cox-2 ablation. These findings have important clinical implications, as combination cancer therapy that includes Zn may improve efficacy
Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction
Reconnection of the self-generated magnetic fields in laser-plasma
interaction was first investigated experimentally by Nilson {\it et al.} [Phys.
Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a
solid target layer. An elongated current sheet (CS) was observed in the plasma
between the two laser spots. In order to more closely model magnetotail
reconnection, here two side-by-side thin target layers, instead of a single
one, are used. It is found that at one end of the elongated CS a fan-like
electron outflow region including three well-collimated electron jets appears.
The ( MeV) tail of the jet energy distribution exhibits a power-law
scaling. The enhanced electron acceleration is attributed to the intense
inductive electric field in the narrow electron dominated reconnection region,
as well as additional acceleration as they are trapped inside the rapidly
moving plasmoid formed in and ejected from the CS. The ejection also induces a
secondary CS
KFe_2Se_2 is the parent compound of K-doped iron selenide superconductors
We elucidate the existing controversies in the newly discovered K-doped iron
selenide (KxFe2-ySe2-z) superconductors. The stoichiometric KFe2Se2 with
\surd2\times\surd2 charge ordering was identified as the parent compound of
KxFe2-ySe2-z superconductor using scanning tunneling microscopy and
spectroscopy. The superconductivity is induced in KFe2Se2 by either Se
vacancies or interacting with the anti-ferromagnetic K2Fe4Se5 compound. Totally
four phases were found to exist in KxFe2-ySe2-z: parent compound KFe2Se2,
superconducting KFe2Se2 with \surd2\times\surd5 charge ordering,
superconducting KFe2Se2-z with Se vacancies and insulating K2Fe4Se5 with
\surd5\times\surd5 Fe vacancy order. The phase separation takes place at the
mesoscopic scale under standard molecular beam epitaxy condition
Characterizing temporary hydrological regimes at a European scale
Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios
Consistent as-similar-as-possible non-isometric surface registration
© 2017 The Author(s)Non-isometric surface registration, aiming to align two surfaces with different sizes and details, has been widely used in computer animation industry. Various existing surface registration approaches have been proposed for accurate template fitting; nevertheless, two challenges remain. One is how to avoid the mesh distortion and fold over of surfaces during transformation. The other is how to reduce the amount of landmarks that have to be specified manually. To tackle these challenges simultaneously, we propose a consistent as-similar-as-possible (CASAP) surface registration approach. With a novel defined energy, it not only achieves the consistent discretization for the surfaces to produce accurate result, but also requires a small number of landmarks with little user effort only. Besides, CASAP is constrained as-similar-as-possible so that angles of triangle meshes are preserved and local scales are allowed to change. Extensive experimental results have demonstrated the effectiveness of CASAP in comparison with the state-of-the-art approaches
Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor
Alkali-doped iron selenide is the latest member of high Tc superconductor
family, and its peculiar characters have immediately attracted extensive
attention. We prepared high-quality potassium-doped iron selenide (KxFe2-ySe2)
thin films by molecular beam epitaxy and unambiguously demonstrated the
existence of phase separation, which is currently under debate, in this
material using scanning tunneling microscopy and spectroscopy. The
stoichiometric superconducting phase KFe2Se2 contains no iron vacancies, while
the insulating phase has a \surd5\times\surd5 vacancy order. The iron vacancies
are shown always destructive to superconductivity in KFe2Se2. Our study on the
subgap bound states induced by the iron vacancies further reveals a
magnetically-related bipartite order in the superconducting phase. These
findings not only solve the existing controversies in the atomic and electronic
structures in KxFe2-ySe2, but also provide valuable information on
understanding the superconductivity and its interplay with magnetism in
iron-based superconductors
Applied fault detection and diagnosis for industrial gas turbine systems
The paper presents readily implementable approaches for fault detection and diagnosis (FDD) based on measurements from multiple sensor groups, for industrial systems. Specifically, the use of hierarchical clustering (HC) and self-organizing map neural networks (SOMNNs) are shown to provide robust and user-friendly tools for application to industrial gas turbine (IGT) systems. HC fingerprints are found for normal operation, and FDD is achieved by monitoring cluster changes occurring in the resulting dendrograms. Similarly, fingerprints of operational behaviour are also obtained using SOMNN based classification maps (CMs) that are initially determined during normal operation, and FDD is performed by detecting changes in their CMs. The proposed methods are shown to be capable of FDD from a large group of sensors that measure a variety of physical quantities. A key feature of the paper is the development of techniques to accommodate transient system operation, which can often lead to false-alarms being triggered when using traditional techniques if the monitoring algorithms are not first desensitized. Case studies showing the efficacy of the techniques for detecting sensor faults, bearing tilt pad wear and early stage pre-chamber burnout, are included. The presented techniques are now being applied operationally and monitoring IGTs in various regions of the world
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