864 research outputs found

    Sky location of Galactic white dwarf binaries in space-based gravitational wave detection

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    Quickly localizing the identified white dwarf (WD) binaries is the basic requirement for the space-based gravitational wave (GW) detection. In fact, the amplitude of GW signals are modulated by the periodic motion of GW detectors on the solar orbit. The intensity of the observed signals is enhanced according to the observation time beyond a year to enhance a high signal to noise ratio (SNR). As data gap exists, the completeness of the data observed for a long time depends on filling gaps in the data. Actually, in a year period, the GW sources have a best observation orbit position of GW detectors, where the detector response intensity of GW is maximum. Thus, the best positions, where the direction of GW source is perpendicular to the detection arms, can be searched for the verified GW sources of the sky map to enhance SNR too. For the three arms response intensity of the GW signals changing more clearly with the location of the GW sources relative to the detector, the noises and the suppression of noise by time delay interferometer are ignored. In the four chosen sources, the two verification WD binaries: J0806 and V407 Vul are observed at the best orbit positions by TAIJI for the short time of 2 and 3 days respectively. The intensities of those GWs are above the values of the TAIJI sensitivity curve, significantly. Compared with a single detector, the network of two detectors does not significantly improve the accuracy of location of the verification binaries. The reason of that result is that one GW source can not be perpendicular to both detectors of TAIJI and LISA. These results imply that the searching of GW signals and parameter estimation of GW sources from the experimental data of the space-based mission do not ignore the orbit positions relevant to GW sources.Comment: 22 pages, 15 figure

    Monopole-charged pulsars and relevant issues

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    The aligned pulsars whose rotation axes and magnetic dipole axes are parallel should be positively charged. The total charge of pulsars is calculated after considering the electromagnetic field in and out the star under a specific condition. The statistical relation between the pulsar's rotation energy loss rate (or the period derivative) and the period may hint that the millisecond radio pulsars with small periods could be low-mass bare strange stars.Comment: 4 pages, 1 figures, and 1 tabl

    Geometric Nonlinear Meshless Analysis of Ribbed Rectangular Plates Based on the FSDT and the Moving Least-Squares Approximation

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    Based on the first-order shear deformation theory (FSDT) and the moving least-squares approximation, a new meshless model to study the geometric nonlinear problem of ribbed rectangular plates is presented. Considering the plate and the ribs separately, the displacement field, the stress, and strain of the plate and the ribs are obtained according to the moving least-squares approximation, the von Karman large deflection theory, and the FSDT. The ribs are attached to the plate by considering the displacement compatible condition along the connections between the ribs and the plate. The virtual strain energy formulation of the plate and the ribs is derived separately, and the nonlinear equilibrium equation of the entire ribbed plate is given by the virtual work principle. In the new meshless model for ribbed plates, there is no limitation to the rib position; for example, the ribs need not to be placed along the mesh lines of the plate as they need to be in FEM, and the change of rib positions will not lead to remeshing of the plate. The proposed model is compared with the FEM models from pieces of literature and ANSYS in several numerical examples, which proves the accuracy of the model

    Intranasal immunization with a helper-dependent adenoviral vector expressing the codon-optimized fusion glycoprotein of human respiratory syncytial virus elicits protective immunity in BALB/c mice

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    BACKGROUND: Human respiratory syncytial virus (RSV) is a serious pediatric pathogen of the lower respiratory tract. Currently, there is no clinically approved vaccine against RSV infection. Recent studies have shown that helper-dependent adenoviral (HDAd) vectors may represent effective and safe vaccine vectors. However, viral challenge has not been investigated following mucosal vaccination with HDAd vector vaccines. METHODS: To explore the role played by HDAd as an intranasally administered RSV vaccine vector, we constructed a HDAd vector encoding the codon optimized fusion glycoprotein (Fsyn) of RSV, designated HDAd-Fsyn, and delivered intranasally HDAd-Fsyn to mice. RESULTS: RSV-specific humoral and cellular immune responses were generated in BALB/c mice, and serum IgG with neutralizing activity was significantly elevated after a homologous boost with intranasal (i.n.) application of HDAd-Fsyn. Humoral immune responses could be measured even 14 weeks after a single immunization. Immunization with i.n. HDAd-Fsyn led to effective protection against RSV infection on challenge. CONCLUSION: The results indicate that HDAd-Fsyn can induce powerful systemic immunity against subsequent i.n. RSV challenge in a mouse model and is a promising candidate vaccine against RSV infection

    A vast-range speed control microchip for retention of all cell types

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    This Technical Note is the first description of a large-scale logarithmic flow-rate damping system designed to retain cells of different adherence, different suspensibility and different motility. The chamber, which can easily retain and cultivate many types of cells, including high-motility cells and swimming cells, via a series of "speed bumps'', readily facilitates cell retention for complex heterogeneous cultures. Yeast cells, red blood cells, rabbit bone marrow aspirate and dinoflagellate swimming cells were introduced into the chip for multi-cell retention, multi-cell culture and observation. Here, we show that the chamber creates a flow field with a ratio of end/start speeds as low as 0.01. The logarithmic distribution of flow-rate within the chamber is controlled precisely by pressure, all of the cell types that we tested were retained easily within the chamber. Many cell-cell interactions were observed, predicting a high potential for the success of on-chip heterogeneous cell experiments.Anthone Elec. Ltd. (Xiamen, China) ; National Natural Science Foundation of Chin

    Bis[μ-2-(2,4-difluoro­phen­yl)-1,3-bis­(1H-1,2,4-triazol-1-yl)propan-2-olato]dicopper(II) bis­(perchlorate)

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    The title complex, [Cu2(C13H11F2N6O)2](ClO4)2, which was hydro­thermally synthesized, contains a binuclear copper cluster (2 symmetry) with a Cu2O2 rhombus [Cu—O = 1.927 (2) Å] formed by donation of two O atoms from two chelate rings. The tridentate function of each ligand is completed by two N atoms coordinated to the two CuII atoms [Cu—N = 1.933 (2) Å]. The separation distance of two CuII atoms in a cluster is 2.988 (1) Å. The dihedral angle between the six-membered chelate rings is 2.13 (9)°. The perchlorate counter-anion is disordered over two sites in a 0.58 (10):0.42 (10) ratio

    Anti-HCV reactive volunteer blood donors distribution character and genotypes switch in Xi'an, China

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    HCV is prevailed in the world as well as in China. Blood transfusion is one of the most common transmission pathways of this pathogen. Although data of HCV infection character were reported during the past years, anti-HCV reactive profile of China donors was not fully clear yet. Furthermore, infection progress was found related to the HCV genotype. Different genotype led to different efficacy when interferon was introduced into HCV therapy. Here we provided character data of HCV infection in China blood donors from the year of 2000 to 2009. The infection rate in local donors was lower than general population and descended from 0.80% to 0.40% or so in recent years. About 83% HCV strains were categorized into genotypes 1b and 2a. But 1b subtype cases climbed and 2a subtype cases decreased. The current study threw more light on HCV infection of blood donors in China, at least in the Northern region
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