11,002 research outputs found
A parallel thinning method based on image marking
2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Current-voltage characteristics of NdFeAsO0.85F0.15 and NdFeAsO0.85 superconductors
The vortex phase diagrams of NdFeAsO0.85F0.15 and NdFeAsO0.85 superconductors
are determined from the analysis of resistivity and current-voltage (I-V)
measurements in magnetic fields up to 9 T. A clear vortex glass to liquid
transition is identified only in the oxygen deficient NdFeAsO0.85, in which I-V
curves can be well scaled onto liquid and glass branches consistent with the
vortex glass theory. With increasing magnetic field, the activation energy U0,
deduced from the Arrhenius plots of resistivity based on the thermally
activated flux-flow model (TAFF), decays more quickly for NdFeAsO0.85F0.15 than
for NdFeAsO0.85. Moreover, the irreversibility field Hirr of NdFeAsO0.85
increases more rapidly than that of NdFeAsO0.85F0.15 with decreasing
temperature. These observations evidence the strong vortex pinning effects,
presumably caused by the enhanced defects and disorders in the oxygen deficient
NdFeAsO0.85. It is inferred that the enhanced defects and disorder can be also
responsible for the vortex glass to liquid transition in the NdFeAsO0.85.Comment: 19 pages, 5 figure
5 GHz TMRT observations of 71 pulsars
We present integrated pulse profiles at 5~GHz for 71 pulsars, including eight
millisecond pulsars (MSPs), obtained using the Shanghai Tian Ma Radio Telescope
(TMRT). Mean flux densities and pulse widths are measured. For 19 normal
pulsars and one MSP, these are the first detections at 5~GHz and for a further
19, including five MPSs, the profiles have a better signal-to-noise ratio than
previous observations. Mean flux density spectra between 400~MHz and 9~GHz are
presented for 27 pulsars and correlations of power-law spectral index are found
with characteristic age, radio pseudo-luminosity and spin-down luminosity. Mode
changing was detected in five pulsars. The separation between the main pulse
and interpulse is shown to be frequency independent for six pulsars but a
frequency dependence of the relative intensity of the main pulse and interpulse
is found. The frequency dependence of component separations is investigated for
20 pulsars and three groups are found: in seven cases the separation between
the outmost leading and trailing components decreases with frequency, roughly
in agreement with radius-to-frequency mapping; in eleven cases the separation
is nearly constant; in the remain two cases the separation between the outmost
components increases with frequency. We obtain the correlations of pulse widths
with pulsar period and estimate the core widths of 23 multi-component profiles
and conal widths of 17 multi-component profiles at 5.0~GHz using Gaussian
fitting and discuss the width-period relationship at 5~GHz compared with the
results at at 1.0~GHz and 8.6~GHz.Comment: 46 pages, 14 figures, 8 Tables, accepted by Ap
High efficiency regeneration and genetic stability analysis of somatic clones of Gynura bicolor DC.
Gynura bicolor DC. is a perennial vegetable and medicinal plant. It is an important source of anthocyanins. The effects of different growth regulators on callus induction and plant regeneration were evaluated. The best SFC index (8.6) of plant regeneration was obtained in combination of 2,4-D at 2.0 mg/l and BA at 0.5 mg/l, and the frequency of regenerating explants was 78.3%. The highest number of shoots per explant was 11. The genetic stability of the regenerants was analyzed by random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) molecular markers and flow cytometry. The results indicated that no somaclonal variation was detected among the regenerants. To our knowledge, this is the first report of somatic clone study in G. bicolor. The high efficient and reproducible protocol will be advanced for the further studies on secondary metabolic products, transformations and breeding of this potential medicinal plant.Key words: Flow cytometry analysis, genetic stability, Gynura bicolor, inter-simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD), regeneration
Fundamental Cycles and Graph Embeddings
In this paper we present a new Good Characterization of maximum genus of a
graph which makes a common generalization of the works of Xuong, Liu, and Fu et
al. Based on this, we find a new polynomially bounded algorithm to find the
maximum genus of a graph
An automatic algorithm for line judgment based on tracing
2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Content-based image retrieval using shape similarity
2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
- …