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Showing papers by "Xiang Zhang published in 2013"


Journal ArticleDOI
22 Mar 2013-Science
TL;DR: A strong photonic SHE resulting in a measured large splitting of polarized light at metasurfaces is reported, which may provide a route for exploiting the spin and orbit angular momentum of light for information processing and communication.
Abstract: The spin Hall effect (SHE) of light is very weak because of the extremely small photon momentum and spin-orbit interaction. Here, we report a strong photonic SHE resulting in a measured large splitting of polarized light at metasurfaces. The rapidly varying phase discontinuities along a metasurface, breaking the axial symmetry of the system, enable the direct observation of large transverse motion of circularly polarized light, even at normal incidence. The strong spin-orbit interaction deviates the polarized light from the trajectory prescribed by the ordinary Fermat principle. Such a strong and broadband photonic SHE may provide a route for exploiting the spin and orbit angular momentum of light for information processing and communication.

1,042 citations


Posted Content
TL;DR: This integrated framework for using Convolutional Networks for classification, localization and detection is the winner of the localization task of the ImageNet Large Scale Visual Recognition Challenge 2013 and obtained very competitive results for the detection and classifications tasks.
Abstract: We present an integrated framework for using Convolutional Networks for classification, localization and detection. We show how a multiscale and sliding window approach can be efficiently implemented within a ConvNet. We also introduce a novel deep learning approach to localization by learning to predict object boundaries. Bounding boxes are then accumulated rather than suppressed in order to increase detection confidence. We show that different tasks can be learned simultaneously using a single shared network. This integrated framework is the winner of the localization task of the ImageNet Large Scale Visual Recognition Challenge 2013 (ILSVRC2013) and obtained very competitive results for the detection and classifications tasks. In post-competition work, we establish a new state of the art for the detection task. Finally, we release a feature extractor from our best model called OverFeat.

902 citations


Journal ArticleDOI
29 Aug 2013-Cell
TL;DR: The evidence suggests that stromal signals resembling those of a distant organ select for cancer cells that are primed for metastasis in that organ, thus illuminating the evolution of metastatic traits in a primary tumor and its distant metastases.

355 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a new class of coherent optical frequency electromagnetic wave amplifiers that deliver intense coherent and directional surface plasmons well below the diffraction barrier, which can enhance significantly light-matter interactions.
Abstract: : Plasmon lasers are a new class of coherent optical frequency electromagnetic wave amplifiers that deliver intense coherent and directional surface plasmons well below the diffraction barrier. The strongly confined electric fields in plasmon lasers can enhance significantly light-matter interactions and bring fundamentally new capabilities to bio-sensing, data storage photolithography and optical communications.

308 citations


Journal ArticleDOI
Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3, Andrew Marshall Adare4  +963 moreInstitutions (95)
TL;DR: In this paper, the ALICE measurement of K^0_S and Lambda production at midrapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV is presented.
Abstract: The ALICE measurement of K^0_S and {\Lambda} production at mid-rapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and in the pT range from 0.4 GeV/c (0.6 GeV/c for {\Lambda}) to 12 GeV/c. The pT dependence of the {\Lambda}/K^0_S ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher pT with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not observed in pp interactions at sqrt(s) = 0.9 TeV and at sqrt(s) = 7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured pT spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of pT, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the pT dependence of the {\Lambda}/K^0_S ratio.

274 citations


Journal ArticleDOI
Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3, Andrew Marshall Adare4  +969 moreInstitutions (88)
11 Jul 2013
TL;DR: In this paper, the ALICE detector was used to measure the long-range correlations between trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons).
Abstract: Angular correlations between unidentified charged trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the transverse-momentum range 0.3 < p(T) < 4 GeV/c. The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range vertical bar n(lab)vertical bar < 0.8. Fourier coefficients are extracted from the long-range correlations projected onto the azimuthal angle difference and studied as a function of p(T) and in intervals of event multiplicity. In high-multiplicity events, the second-order coefficient for protons, 4, is observed to be smaller than that for pions, v(2)(pi), up to about p(T) = 2 GeV/c. To reduce correlations due to jets, the per-trigger yield measured in low-multiplicity events is subtracted from that in high-multiplicity events. A two-ridge structure is obtained for all particle species. The Fourier decomposition of this structure shows that the second-order coefficients for pions and kaons are similar. The v(2)(p) is found to be smaller at low P-T and larger at higher p(T) than v(2)(pi), with a crossing occurring at about 2 GeV/c. This is qualitatively similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass ordering effect at low transverse momenta is consistent with expectations from hydrodynamic model calculations assuming a collectively expanding system. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.

271 citations


Journal ArticleDOI
06 Dec 2013-Science
TL;DR: It is shown that metamaterials can be designed with optical properties that relax the phase-matching requirements in nonlinear optics, and the experimental demonstration of phase mismatch–free nonlinear generation in a zero-index optical meetamaterial is reported.
Abstract: Phase matching is a critical requirement for coherent nonlinear optical processes such as frequency conversion and parametric amplification. Phase mismatch prevents microscopic nonlinear sources from combining constructively, resulting in destructive interference and thus very low efficiency. We report the experimental demonstration of phase mismatch-free nonlinear generation in a zero-index optical metamaterial. In contrast to phase mismatch compensation techniques required in conventional nonlinear media, the zero index eliminates the need for phase matching, allowing efficient nonlinear generation in both forward and backward directions. We demonstrate phase mismatch-free nonlinear generation using intrapulse four-wave mixing, where we observed a forward-to-backward nonlinear emission ratio close to unity. The removal of phase matching in nonlinear optical metamaterials may lead to applications such as multidirectional frequency conversion and entangled photon generation.

271 citations


Journal ArticleDOI
E. Abbas, Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3  +1019 moreInstitutions (91)
TL;DR: The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE and is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction as mentioned in this paper.
Abstract: ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton-proton, proton-nucleus and nucleus-nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE. In addition to its core function as a trigger source, the VZERO system is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction in nucleus-nucleus collisions. After describing the VZERO system, this publication presents its performance over more than four years of operation at the LHC.

271 citations


Journal ArticleDOI
TL;DR: For the first time, a metamaterial is experimentally demonstrated that traps broadband acoustic waves and spatially separates different frequency components, as the result of dispersion and wave velocity control by designed gradient subwavelength structures.
Abstract: Spatial modulation of sound velocity below the wavelength scale can introduce strong frequency-dependent acoustic responses in tailored composite materials, regardless the fact that most natural bulk materials have negligible acoustic dispersions. Here, for the first time, we experimentally demonstrate a metamaterial that traps broadband acoustic waves and spatially separates different frequency components, as the result of dispersion and wave velocity control by designed gradient subwavelength structures. The trapping positions can be predicted by the microscopic picture of balanced interplay between the acoustic resonance inside individual apertures and the mutual coupling among them. With the enhanced wave-structure interactions and the tailored frequency responses, such metamaterial allows precise spatial-spectral control of acoustic waves and opens new venue for high performance acoustic wave sensing, filtering, and nondestructive metrology.

257 citations


Journal ArticleDOI
TL;DR: In this paper, a spin-mechanical coupling with a built-in nitrogen-vacancy center inside the nanodiamond was proposed to generate large quantum superposition states and arbitrary Fock states.
Abstract: We propose a method to generate and detect large quantum superposition states and arbitrary Fock states for the oscillational mode of an optically levitated nanocrystal diamond. The nonlinear interaction required for the generation of non-Gaussian quantum states is enabled through the spin-mechanical coupling with a built-in nitrogen-vacancy center inside the nanodiamond. The proposed method allows the generation of large superpositions of nanoparticles with millions of atoms and the observation of the associated spatial quantum interference under reasonable experimental conditions.

232 citations


Journal ArticleDOI
TL;DR: The clinical manifestation of metastasis dormancy in ER+ tumors, the current biologic insights regarding tumor dormancy obtained from various experimental models, and the clinical challenges to predict, detect, and treat dormant metastases are reviewed.
Abstract: About 20% to 40% of patients with breast cancer eventually develop recurrences in distant organs, which are often not detected until years to decades after the primary tumor diagnosis. This phenomenon is especially pronounced in estrogen receptor-positive (ER(+)) breast cancer, suggesting that ER(+) cancer cells may stay dormant for a protracted period of time, despite adjuvant therapies. Multiple mechanisms have been proposed to explain how cancer cells survive and remain in dormancy, and how they become reactivated and exit dormancy. These mechanisms include angiogenic switch, immunosurveillance, and interaction with extracellular matrix and stromal cells. How to eradicate or suppress these dormant cancer cells remains a major clinical issue because of the lack of knowledge about the biologic and clinical nature of these cells. Herein, we review the clinical manifestation of metastasis dormancy in ER(+) tumors, the current biologic insights regarding tumor dormancy obtained from various experimental models, and the clinical challenges to predict, detect, and treat dormant metastases. We also discuss future research directions toward a better understanding of the biologic mechanisms and clinical management of ER(+) dormant metastasis.

Journal ArticleDOI
E. Abbas, Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3  +1008 moreInstitutions (92)
TL;DR: In this article, the first wide-range measurement of the charged particle pseudorapidity density distribution, for different centralities (the 0-5, 5-10, 10-20, and 20-30% most central events) in Pb-Pb collisions at root s(NN) = 2.76 TeV at the LHC was performed using the full coverage of the ALICE detectors, -5.0 < eta < 5.5.

Journal ArticleDOI
TL;DR: In this paper, the dispersion of surface plasmons on a simple grating structure was used to realize normal, non-divergent as well as anomalous diffraction of surfaces.
Abstract: Metasurfaces have recently emerged as an innovative approach to control light propagation with unprecedented capabilities. Different from previous work concentrating on steering far-field propagating waves, here we demonstrate that metallic metasurfaces can efficiently and effectively manipulate surface plasmons in the near-field regime. By engineering the dispersion of surface plasmons on a simple grating structure, we are able to realize normal, non-divergent as well as anomalous diffraction of surface plasmons. In particular, all-angle and broadband negative refraction of surface plasmons is achieved, largely attributed to the uniquely designed hyperbolic constant frequency contour of surface plasmons propagating along the metasurface.

Journal ArticleDOI
TL;DR: Unique opportunities arise from exceptional points that coalesce states of an open system in synthetic photonic media, where delicately balanced complex dielectric functions produce unprecedented optical properties.
Abstract: Unique opportunities arise from exceptional points that coalesce states of an open system in synthetic photonic media, where delicately balanced complex dielectric functions produce unprecedented optical properties.

Journal ArticleDOI
TL;DR: Optical scattering from the one-way invisible cloak can be further engineered to realize more interesting effects, for example, creating a unidirectional optical illusion of the concealed object.
Abstract: We propose a one-way invisible cloak using transformation optics of parity-time (PT) symmetric optical materials. At the spontaneous PT-symmetry breaking point, light is scattered only for incidence along one direction since the phase-matching condition is unidirectionally satisfied, making the cloak one-way invisible. Moreover, optical scattering from the one-way cloak can be further engineered to realize more interesting effects, for example, creating a unidirectional optical illusion of the concealed object.

Journal ArticleDOI
E. Abbas, Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3  +1011 moreInstitutions (91)
TL;DR: In this paper, the authors reported the first measurement of J/psi elliptic flow v(2) in heavy-ion collisions at the LHC using the ALICE detector in Pb-Pb collisions at root s(NN) = 2.76 TeV in the rapidity range 2.5 < y < 4.
Abstract: We report on the first measurement of inclusive J/psi elliptic flow v(2) in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at root s(NN) = 2.76 TeV in the rapidity range 2.5 < y < 4.0. The dependence of the J/psi v(2) on the collision centrality and on the J/psi transverse momentum is studied in the range 0 <= p(T) < 10 GeV/c. For semicentral Pb-Pb collisions at root s(NN) = 2.76 TeV, an indication of nonzero v(2) is observed with a largest measured value of v(2) = 0.116 +/-0.046(stat) +/- 0.029(syst) for J/psi in the transverse momentum range 2 <= p(T) < 4 GeV/c. The elliptic flow measurement complements the previously reported ALICE results on the inclusive J/psi nuclear modification factor and favors the scenario of a significant fraction of J/psi production from charm quarks in a deconfined partonic phase.

01 Jan 2013
TL;DR: The transverse momentum (p(T)) distribution of primary charged particles is measured in minimum bias p+Pb collisions at the LHC and the nuclear modification factor R(pPb) is consistent with unity for p(T) above 2 GeV/c.

Journal ArticleDOI
TL;DR: In this paper, the formation and extraordinary Li-storage properties of TiO2 hollow nanofibers by co-axial electrospinning in both the half-cell and full-cell configurations were investigated.
Abstract: We report the formation and extraordinary Li-storage properties of TiO2 hollow nanofibers by co-axial electrospinning in both the half-cell and full-cell configurations. Li-insertion properties are first evaluated as anodes in the half-cell configuration (Li/TiO2 hollow nanofibers) and we found that reversible insertion of ∼0.45 moles is feasible at a current density of 100 mA g−1. The half-cell displayed a good cyclability and retained 84% of its initial reversible capacity after 300 galvanostatic cycles. The full-cell is fabricated with a commercially available olivine phase LiFePO4 cathode under optimized mass loading. The LiFePO4/TiO2 hollow nanofiber cell delivered a reversible capacity of 103 mA h g−1 at a current density of 100 mA g−1 with an operating potential of ∼1.4 V. Excellent cyclability is noted for the full-cell configuration, irrespective of the applied current densities, and it retained 88% of reversible capacity after 300 cycles in ambient conditions at a current density of 100 mA g−1.

Journal ArticleDOI
TL;DR: In this paper, the microscopic origin of electroluminescence from monolayer MoS2 fabricated on a heavily p-type doped silicon substrate was identified by comparing the photoluminance and electroluminance of a diode, direct exciton and bound-exciton related recombination processes.
Abstract: Excitons in MoS2 dominate the absorption and emission properties of the two-dimensional system. Here, we study the microscopic origin of the electroluminescence from monolayer MoS2 fabricated on a heavily p-type doped silicon substrate. By comparing the photoluminescence and electroluminescence of a MoS2 diode, direct-exciton and bound-exciton related recombination processes can be identified. Auger recombination of the exciton-exciton annihilation of bound exciton emission is observed under a high electron-hole pair injection rate at room temperature. We expect the direct exciton-exciton annihilation lifetime to exceed the carrier lifetime, due to the absence of any noticeable direct exciton saturation. We believe that our method of electrical injection opens a new route to understand the microscopic nature of the exciton recombination and facilitate the control of valley and spin excitation in MoS2.

Proceedings ArticleDOI
11 Aug 2013
TL;DR: CGC (Co-regularized Graph Clustering), based on non-negative matrix factorization (NMF), has several advantages over the existing methods, and provides users with the extent to which the cross-domain instance relationship violates the in-domain clustering structure, and thus enables users to re-evaluate the consistency of the relationship.
Abstract: Multi-view graph clustering aims to enhance clustering performance by integrating heterogeneous information collected in different domains. Each domain provides a different view of the data instances. Leveraging cross-domain information has been demonstrated an effective way to achieve better clustering results. Despite the previous success, existing multi-view graph clustering methods usually assume that different views are available for the same set of instances. Thus instances in different domains can be treated as having strict one-to-one relationship. In many real-life applications, however, data instances in one domain may correspond to multiple instances in another domain. Moreover, relationships between instances in different domains may be associated with weights based on prior (partial) knowledge. In this paper, we propose a flexible and robust framework, CGC (Co-regularized Graph Clustering), based on non-negative matrix factorization (NMF), to tackle these challenges. CGC has several advantages over the existing methods. First, it supports many-to-many cross-domain instance relationship. Second, it incorporates weight on cross-domain relationship. Third, it allows partial cross-domain mapping so that graphs in different domains may have different sizes. Finally, it provides users with the extent to which the cross-domain instance relationship violates the in-domain clustering structure, and thus enables users to re-evaluate the consistency of the relationship. Extensive experimental results on UCI benchmark data sets, newsgroup data sets and biological interaction networks demonstrate the effectiveness of our approach.

Journal ArticleDOI
TL;DR: The giant suppression of photobleaching and a prolonged lifespan of single fluorescent molecules via the Purcell effect in plasmonic nanostructures are reported and the potential of using thePurcell effect to manipulate photochemical reactions at the subwavelength scale is demonstrated.
Abstract: We report giant suppression of photobleaching and a prolonged lifespan of single fluorescent molecules via the Purcell effect in plasmonic nanostructures. The plasmonic structures enhance the spontaneous emission of excited fluorescent molecules, reduce the probability of activating photochemical reactions that destroy the molecules, and hence suppress the bleaching. Experimentally, we observe up to a 1000-fold increase in the total number of photons that we can harvest from a single fluorescent molecule before it bleaches. This approach demonstrates the potential of using the Purcell effect to manipulate photochemical reactions at the subwavelength scale.

Journal ArticleDOI
TL;DR: A framework and several algorithms that automatically recognize building patterns from topographic data, with a focus on collinear and curvilinear alignments are proposed, where a mechanism is proposed to combine results from different algorithms to improve the recognition quality.
Abstract: Building patterns are important features that should be preserved in the map generalization process. However, the patterns are not explicitly accessible to automated systems. This paper proposes a framework and several algorithms that automatically recognize building patterns from topographic data, with a focus on collinear and curvilinear alignments. For both patterns two algorithms are developed, which are able to recognize alignment-of-center and alignment-of-side patterns. The presented approach integrates aspects of computational geometry, graph-theoretic concepts and theories of visual perception. Although the individual algorithms for collinear and curvilinear patterns show great potential for each type of the patterns, the recognized patterns are neither complete nor of enough good quality. We therefore advocate the use of a multi-algorithm paradigm, where a mechanism is proposed to combine results from different algorithms to improve the recognition quality. The potential of our method is demonstrated by an application of the framework to several real topographic datasets. The quality of the recognition results are validated in an expert survey.

Journal ArticleDOI
TL;DR: In this article, an optical plasmonic metamaterial composed of double disks has been shown to exhibit a well-behaved toroidal cavity mode that exhibits a large Purcell factor due to its deep subwavelength mode volume.
Abstract: Dynamic dipolar toroidal response is demonstrated by an optical plasmonic metamaterial composed of double disks. This response with a hotspot of localized $E$-field concentration is a well-behaved toroidal cavity mode that exhibits a large Purcell factor due to its deep-subwavelength mode volume. All-optical Hall effect (photovoltaic) is observed numerically attributed to the nonlinear phenomenon of unharmonic plasmon oscillations, which exhibits an interesting analogy with the magnetoelectric effect in multiferroic systems. The result shows a promising avenue to explore various intriguing optical phenomena associated with this dynamic toroidal moment.

Journal ArticleDOI
TL;DR: Nanoporous silicon (Si) networks with controllable porosity and thickness are fabricated by a simple and scalable electrochemical process, and then released from Si wafers and transferred to flexible and conductive substrates to serve as high performance Li-ion battery electrodes.
Abstract: Nanoporous silicon (Si) networks with controllable porosity and thickness are fabricated by a simple and scalable electrochemical process, and then released from Si wafers and transferred to flexible and conductive substrates. These nanoporous Si networks serve as high performance Li-ion battery electrodes, with an initial discharge capacity of 2570 mA h g−1, above 1000 mA h g−1 after 200 cycles without any electrolyte additives.

Journal ArticleDOI
TL;DR: Results from the meta-analysis suggest that the rs3025039 (C>T) polymorphism of the VEGF gene increases the risk of endometriosis, but the rs699947 (A>C) and rs1570360 (G>A) polymorphisms might be protective factors for endometRIosis.
Abstract: Endometriosis is a chronic gynecological disease defined as the presence of the endometrium outside the uterine cavity. Endometriosis is a multifactorial and polygenic disease in which angiogenesis may be implicated. Angiogenesis is under the control of numerous inducers, including vascular endothelial growth factor (VEGF). Many studies have reported that VEGF plays a role in the progression of the disease, but individually published studies showed inconclusive results. We investigated the association between VEGF polymorphisms and the susceptibility to endometriosis. The MEDLINE, EMBASE, Web of Science, and CBM databases were searched for all articles published up to June 25, 2012, which addressed VEGF polymorphisms and endometriosis risk. We investigated the potential association between VEGF polymorphisms and the risk of endometriosis. Fourteen studies were included with a total of 3313 endometriosis cases and 3393 healthy controls. Meta-analysis results showed that the rs699947 (A>C) and rs1570360 (G>A) polymorphisms in the VEGF gene were associated with a decreased risk of endometriosis, while rs3025039 (C>T) might increase the risk of endometriosis. However, the rs833061 (T>C) and rs2010963 (G>C) polymorphisms of the VEGF gene did not appear to have an influence on endometriosis susceptibility. Results from the meta-analysis suggest that the rs3025039 (C>T) polymorphism of the VEGF gene increases the risk of endometriosis, but the rs699947 (A>C) and rs1570360 (G>A) polymorphisms might be protective factors for endometriosis.

Journal ArticleDOI
TL;DR: In this article, the authors used NiO and commercial carbon nanotubes (CNTs) as electrode materials for electrochemical capacitors with high energy storage capacities, and showed that the specific capacitance of the electrode material for 10%, 30% and 50% CNTs are 279, 242 and 112 −F/g, respectively in an aqueous 1 −M KOH electrolyte at a charge rate of 0.33 −A/g.

Journal ArticleDOI
Betty Abelev1, Jaroslav Adam2, Dagmar Adamová3, Andrew Marshall Adare4  +1030 moreInstitutions (92)
TL;DR: In this paper, the particle pair yields per trigger particle obtained from di-hadron azimuthal correlations in pp collisions at root s = 0.9, 2.76, and 7TeV recorded with the ALICE detector are studied as a function of the charged particle multiplicity.
Abstract: We present the measurements of particle pair yields per trigger particle obtained from di-hadron azimuthal correlations in pp collisions at root s = 0.9, 2.76, and 7TeV recorded with the ALICE detector. The yields are studied as a function of the charged particle multiplicity. Taken together with the single particle yields the pair yields provide information about parton fragmentation at low transverse momenta, as well as on the contribution of multiple parton interactions to particle production. Data are compared to calculations using the PYTHIA6, PYTHIA8, and PHOJET event generators.

Journal ArticleDOI
TL;DR: In this article, the features of metal optical components can be exploited to enhance typically weak magneto-optic effects, which may help to reduce the size of photonic devices.
Abstract: Enhancing magneto-optic effects may help to reduce the size of photonic devices. Recent research by several groups shows that the features of metal optical components can be exploited to enhance typically weak magneto-optic effects.

Journal ArticleDOI
TL;DR: In this article, a detailed study of magnetic properties of antiperovsite compound Mn3Cu0.7Ga0.3N was presented, which consistently demonstrated the existence of spin-glass states in Mn3cu0.
Abstract: We present a detailed study of magnetic properties of antiperovsite compound Mn3Cu0.7Ga0.3N. Ac susceptibility measurements show a peak around “freezing temperature” (Tf), with the peak position shifting as a function of the driving frequency f and magnetic field H. Magnetic relaxation measurements show a slow decay of the remanent magnetization with time below Tf. These findings consistently demonstrate the existence of spin-glass states in Mn3Cu0.7Ga0.3N. The behavior may be attributed to either a small amount of disorder, arising from the random occupation of 1a sites in the space group Pm-3m by mixed Cu/Ga atoms, or the common frustration, or both.

Journal ArticleDOI
TL;DR: This article firstly analyses the requirements (constraints) related to the generalization of building alignments, then, it focuses on three more specific constraints, i.e. on existence, orientation of alignments and spatial distribution of composing buildings.
Abstract: Evaluation is a key step to examine the quality of generalized maps with respect to map requirements. Map generalization facilitates the recognition of pattern generating processes by preserving and highlighting the patterns at smaller scales. This article focuses specifically on the evaluation of building patterns in topographic maps that are generalized from large to mid scales. Currently, there is a lack of knowledge and functionality on automatically evaluating how these patterns are generalized. The issues of the evaluation range from missing formal map requirements on building alignments to missing automated evaluation techniques. This article firstly analyses the requirements constraints related to the generalization of building alignments. Then, it focuses on three more specific constraints, i.e. on existence, orientation of alignments and spatial distribution of composing buildings. Later, a three-step approach is proposed to 1 recognize and 2 match alignments from source and generalized datasets and 3 evaluate building alignments in generalized datasets. Besides, many-to-many and partial matching between initial and target alignments is a side effect of generalization, which reduces the reliability of the evaluation results. This article introduces a confidence indicator to document the reliability and to inform intended users e.g. cartographers and/or systems about the reliability of evaluation decisions. The effectiveness of our approach is demonstrated by evaluating the alignments in both interactively manually generalized maps and automated generalized maps. Finally, we discuss how our approach can be used to control automated generalization and identify further improvements.