1,572 research outputs found
Unambiguous Tracking Method Based on Combined Correlation Functions for sine/cosine-BOC CBOC and AltBOC Modulated Signals
Unambiguous tracking for Binary Offset Carrier (BOC) modulated signals is an important requirement of modern Global Navigation Satellite System (GNSS) receivers. An unambiguous tracking method based on combined correlation functions for even/odd order sine/cosine-BOC, Composite BOC(CBOC) and Alternate BOC(AltBOC) modulated signals is proposed. Firstly, a unitary mathematical formulation for all kinds of BOC modulations is introduced. Then an unambiguous tracking method is proposed based on the formulation and the idea of pseudo correlation function (PCF) method. Finally, the tracking loop based on the proposed method is designed. Simulation results indicate that the proposed method can remove side peaks while retaining the sharp main peak for all kinds of BOC modulations. The tracking performance for AltBOC is examined and the results show that the proposed method has better performance in thermal noise and long-delay multipath mitigation than the traditional unambiguous tracking methods
Theory of Electron-Phonon Dynamics in Insulating Nanoparticles
We discuss the rich vibrational dynamics of nanometer-scale semiconducting
and insulating crystals as probed by localized electronic impurity states, with
an emphasis on nanoparticles that are only weakly coupled to their environment.
Two principal regimes of electron-phonon dynamics are distinguished, and a
brief survey of vibrational-mode broadening mechanisms is presented. Recent
work on the effects of mechanical interaction with the environment is
discussed.Comment: Revte
Asymmetry Parameter of the by Analyzing the Transition Form Factors within QCD
Separating the mixture of the and states, the
transition form factors are calculated in
the three-point QCD sum rules approach. The longitudinal, transverse and total
decay widths as well as the asymmetry parameter, characterizing the
polarization of the axial and the branching ratio for these
decays are evaluated.Comment: 25 pages, 3 figures, 3 table
Targeting lentiviral vectors to antigen-specific immunoglobulins
Gene transfer into B cells by lentivectors can provide an alternative approach to managing B lymphocyte malignancies and autoreactive B cell-mediated autoimmune diseases. These pathogenic B cell Populations can be distinguished by their surface expression of monospecific immunoglobulin. Development of a novel vector system to deliver genes to these specific B cells could improve the safety and efficacy of gene therapy. We have developed an efficient rnethod to target lentivectors to monospecific immunoglobulin-expressing cells in vitro and hi vivo. We were able to incorporate a model antigen CD20 and a fusogenic protein derived from the Sindbis virus as two distinct molecules into the lentiviral Surface. This engineered vector could specifically bind to cells expressing Surface immunoglobulin recognizing CD20 (αCD20), resulting in efficient transduction of target cells in a cognate antigen-dependent manner in vitro, and in vivo in a xenografted tumor model. Tumor suppression was observed in vivo, using the engineered lentivector to deliver a suicide gene to a xenografted tumor expressing αCD20. These results show the feasibility of engineering lentivectors to target immunoglobulin-specific cells to deliver a therapeutic effect. Such targeting lentivectors also Could potentially be used to genetically mark antigen-specific B cells in vivo to study their B cell biology
Development of a multiplex event-specific PCR assay for detection of genetically modified rice
Global rice supplies have been found contaminated with unapproved varieties of genetically modified (GM) rice in recent years, which has led to product recalls in several of countries. Faster and more effective detection of GM contamination can prevent adulterated food, feed and seed from being consumed and grown, minimize the potential environmental, health or economic damage. In this study, a simple, reliable and cost-effective multiplex polymerase chain reaction (PCR) assay for identifying genetic modifications of TT51-1, Kemingdao1 (KMD1) and Kefeng6 (KF6) rice was developed by using the event-specific fragment. The limit of detection (LOD) for each event in the multiplex PCR is approximately 0.1%. Developed multiplex PCR assays can provide a rapid and simultaneous detection of GM rice
Rare Semileptonic Decays of Heavy Mesons with Flavor SU(3) Symmetry
In this paper, we calculate the decay rates of , , , and
semileptonic decay processes, in which only the light
quarks decay, while the heavy flavors remain unchanged. The branching ratios of
these decay processes are calculated with the flavor SU(3) symmetry. The
uncertainties are estimated by considering the SU(3) breaking effect. We find
that the decay rates are very tiny in the framework of the Standard Model. We
also estimate the sensitivities of the measurements of these rare decays at the
future experiments, such as BES-III, super- and LHC-.Comment: 4 pages and 1 figure, accepted by European Physical Journal
Interference between the halves of a double-well trap containing a Bose-Einstein condensate
Interference between the halves of a double-well trap containing a
Bose-Einstein condensate is studied. It is found that when the atoms in the two
wells are initially in the coherent state, the intensity exhibits collapses and
revivals, but it does not for the initial Fock states. Whether the initial
states are in the coherent states or in a Fock states, the fidelity time has
nothing to do with collision. We point out that interference and its fidelity
can be adjusted experimentally by properly preparing the number and initial
states of the system.Comment: 10 pages, 3 figures, accepted by Phy. rev.
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