415 research outputs found

    Reconstruction of SU(5) Grand Unified Model In Noncommutative Geometry Approach

    Get PDF
    Based on the generalized gauge theory on M4×Z2×Z3M^4\times Z_2\times Z_3, we reconstructed the realistic SU(5) Grand Unified model by a suitable assignment of fermion fields. The action of group elements Z2Z_2 on fermion fields is the charge conjugation while the action of Z3Z_3 elements represent generation translation. We find that to fit the spontaneous symmetry breaking and gauge hierarchy of SU(5) model a linear term of curvature has to be introduced. A new mass relation is obtained in our reconstructed model.Comment: 16 pages, Late

    Lithotripter Shockwave-Induced Enhancement of Mouse Melanoma Lung Metastasis: Dependence on Cavitation Nucleation

    Full text link
    Purpose: To confirm a previous report of metastasis enhancement by lithotripter shockwaves (LSW) and to test the hypothesis that this effect is attributable to cavitation. Materials and Methods: The metastatic B16-D5 melanoma cell line was implanted on the hind legs of female C57/b16 mice 12 days before tumor treatment. The tumors were treated with 500 LSW in a waterbath arrangement. The effect of augmented cavitation nucleation was tested by intratumor injection of air bubbles or ultrasound contrast agent gas bodies (UCAGB). The primary tumor was surgically removed on day 1 after treatment. The six groups of mice were sham, LSW, sham + air bubbles, LSW + air bubbles, sham + UCAGB, and LSW + UCAGB. Data were collected for the 113 mice that survived at least 25 days. Lung evaluations were performed blind after 2 weeks of bleaching in Fekete's solution. Results: The outcomes of the three sham groups were very similar and indicated that the simple injection of material into the tumor did not increase metastasis. In comparison with the pooled shams, both the LSW + air bubbles and LSW + UCAGB groups had statistically significant increases in metastasis counts. Only the LSW + UCAGB group had a significant increase in incidence of metastasis relative to the pooled shams. The LSW + UCAGB also had significantly reduced survival. Conclusion: Shockwaves can enhance metastasis from tumors, and this effect is attributable to cavitation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63207/1/end.2004.18.925.pd

    Multi-frame image restoration method for novel rotating synthetic aperture imaging system

    Get PDF
    Abstract The novel rotating synthetic aperture (RSA) optical imaging system is an important development direction for future high-resolution optical remote sensing satellites in geostationary orbit. However, owing to the rotating rectangular pupil, the point spread function of the RSA system has an asymmetric spatial distribution, and the images obtained using the primary mirror from different rotation angles have nonuniform blur degradation. Moreover, platform vibration and pupil rotation have coupling effects on the RSA imaging, resulting in further radiometric and geometric quality degradation. To address these problems, the image degradation characteristics are first analyzed according to the imaging mechanism. Then, combined with the theory of mutual information, an image registration method is suggested by introducing the orientation gradient information. From this, a multi-frame image restoration model is proposed based on the directional gradient prior of the RSA system image. From the perspective of interpretation and application, when the aspect ratio is less than 3, the proposed inversion restoration method can achieve a satisfactory processing performance. This work can provide engineering application reference for the future space application of RSA imaging technology

    Novel Schemes for Directly Measuring Entanglement of General States

    Full text link
    An intrinsic relation between maximally entangled states and entanglement measures is revealed, which plays a role in establishing connections for different entanglement quantifiers. We exploit the basic idea and propose a framework to construct schemes for directly measuring entanglement of general states. In particular, we demonstrate that rank-1 local factorizable projective measurements, which are achievable with only one copy of entangled state involved at a time in a sequential way, are sufficient to directly determine the concurrence of arbitrary two-qubit entangled state

    Microwave photo-association of fine-structure-induced Rydberg (n+2)D5/2nFJ(n+2)D_{5/2}nF_{J} macro-dimer molecules of cesium

    Full text link
    Long-range (n+2)D5/2 nFJ(n+2)D_{5/2} \, nF_J Rydberg macro-dimers are observed in an ultracold cesium Rydberg gas for 39≤n≤4839\leq n\leq48. Strong dipolar "flip" (⟨D5/2F5/2∣V^dd∣F5/2D5/2⟩\langle D_{5/2} F_{5/2} \vert \hat{V}_{dd} \vert F_{5/2} D_{5/2} \rangle, ⟨D5/2F7/2∣V^dd∣F7/2D5/2⟩\langle D_{5/2} F_{7/2} \vert \hat{V}_{dd} \vert F_{7/2} D_{5/2} \rangle) and "cross" (⟨D5/2F7/2∣V^dd∣F5/2D5/2⟩\langle D_{5/2} F_{7/2} \vert \hat{V}_{dd} \vert F_{5/2} D_{5/2} \rangle) couplings lead to bound, fine-structure-mixed (n+2)D5/2nFJ(n+2)D_{5/2}nF_J macro-dimers at energies between the FJF_J fine-structure levels. The DFDF macro-dimers are measured by microwave photo-association from optically prepared [(n+2)D5/2]2[(n+2)D_{5/2}]_2 Rydberg pair states. Calculated adiabatic potential curves are used to elucidate the underlying physics and to model the DFDF macro-dimer spectra, with good overall agreement. Microwave photo-association allows Franck-Condon tuning, which we have studied by varying the detuning of a Rydberg-atom excitation laser. Further, in Stark spectroscopy we have measured molecular DC electric polarizabilities that are considerably larger than those of the atomic states. The large molecular polarizabilities may be caused by high-ℓ\ell mixing. The observed linewidths of the Stark-shifted molecular lines provide initial evidence for intra-molecular induced-dipole-dipole interaction
    • …
    corecore