Binary Stellar Population Synthesis Model

Using Yunnan evolutionary population synthesis (EPS) models, we present integrated colours, integrated spectral energy distributions (ISEDs) and absorption-line indices defined by the Lick Observatory image dissector scanner (Lick/IDS) system, for an extensive set of instantaneous-burst binary stellar populations (BSPs) with interactions. By comparing the results for populations with and without interactions we show that the inclusion of binary interactions makes the appearance of the population substantially bluer. This effect raises the derived age and metallicity of the population. To be used in the studies of modern spectroscopic galaxy surveys at intermediate/high spectral resolution, we also present intermediate- (3A) and high-resolution (~0.3A) ISEDs and Lick/IDS absorption-line indices for BSPs. To directly compare with observations the Lick/IDS absorption indices are also presented by measuring them directly from the ISEDs.Comment: 2 pages 2 figure

The Effect of Binary Interactions in Infrared Passbands

We present the integrated J, H, K, L, M and N magnitudes and the colours involving infrared bands, for an extensive set of instantaneous-burst binary stellar populations (BSPs) by using evolutionary population synthesis (EPS). By comparing the results for BSPs WITH and WITHOUT binary interactions we show that the inclusion of binary interactions makes the magnitudes of populations larger (fainter) and the integrated colours smaller (bluer) for t > 1Gyr. Also, we compare our model magnitudes and colours with those of Bruzual & Charlot (2003, hereafter BC03) and Maraston (2005, hereafter M05). At last, we compare these model broad colours with Magellanic Clouds globular clusters (GCs) and Milky Way GCs. In (V-R)-[Fe/H] and (V-I)-[Fe/H] diagrams it seems that our models match the observations better than those of BC03 and M05.Comment: 2 page 3 figure

Password Cracking and Countermeasures in Computer Security: A Survey

With the rapid development of internet technologies, social networks, and other related areas, user authentication becomes more and more important to protect the data of the users. Password authentication is one of the widely used methods to achieve authentication for legal users and defense against intruders. There have been many password cracking methods developed during the past years, and people have been designing the countermeasures against password cracking all the time. However, we find that the survey work on the password cracking research has not been done very much. This paper is mainly to give a brief review of the password cracking methods, import technologies of password cracking, and the countermeasures against password cracking that are usually designed at two stages including the password design stage (e.g. user education, dynamic password, use of tokens, computer generations) and after the design (e.g. reactive password checking, proactive password checking, password encryption, access control). The main objective of this work is offering the abecedarian IT security professionals and the common audiences with some knowledge about the computer security and password cracking, and promoting the development of this area.Comment: add copyright to the tables to the original authors, add acknowledgement to helpe

Polarized Curvature Radiation in Pulsar Magnetosphere

The propagation of polarized emission in pulsar magnetosphere is investigated in this paper. The polarized waves are generated through curvature radiation from the relativistic particles streaming along curved magnetic field lines and co-rotating with the pulsar magnetosphere. Within the 1/{\deg} emission cone, the waves can be divided into two natural wave mode components, the ordinary (O) mode and the extraord nary (X) mode, with comparable intensities. Both components propagate separately in magnetosphere, and are aligned within the cone by adiabatic walking. The refraction of O-mode makes the two components separated and incoherent. The detectable emission at a given height and a given rotation phase consists of incoherent X-mode and O-mode components coming from discrete emission regions. For four particle-density models in the form of uniformity, cone, core and patches, we calculate the intensities for each mode numerically within the entire pulsar beam. If the co-rotation of relativistic particles with magnetosphere is not considered, the intensity distributions for the X-mode and O-mode components are quite similar within the pulsar beam, which causes serious depolarization. However, if the co-rotation of relativistic particles is considered, the intensity distributions of the two modes are very different, and the net polarization of out-coming emission should be significant. Our numerical results are compared with observations, and can naturally explain the orthogonal polarization modes of some pulsars. Strong linear polarizations of some parts of pulsar profile can be reproduced by curvature radiation and subsequent propagation effect.Comment: 12 pages, 9 figures, Accepted for publication in MNRA

Binary interactions and UV photometry on photometric redshift

Using the Hyperz code (Bolzonella et al. 2000) we present photometric redshift estimates for a random sample of galaxies selected from the SDSS/DR7 and GALEX/DR4, for which spectroscopic redshifts are also available. We confirm that the inclusion of ultraviolet photometry improves the accuracy of photo-zs for those galaxies with g*-r* < 0.7 and z_spec < 0.2. We also address the problem of how binary interactions can affect photo-z estimates, and find that their effect is negligible.Comment: 2 pages 1 figure

A note on modular forms and generalized anomaly cancellation formulas

By studying modular invariance properties of some characteristic forms, we prove some new anomaly cancellation formulas which generalize the Han-Zhang and Han-Liu-Zhang anomaly cancellation formula

Thermal and non-thermal emission in the Cygnus X region

Radio continuum observations detect non-thermal synchrotron and thermal bremsstrahlung radiation. Separation of the two different emission components is crucial to study the properties of diffuse interstellar medium. The Cygnus X region is one of the most complex areas in the radio sky which contains a number of massive stars and HII regions on the diffuse thermal and non-thermal background. More supernova remnants are expected to be discovered. We aim to develop a method which can properly separate the non-thermal and thermal radio continuum emission and apply it to the Cygnus X region. The result can be used to study the properties of different emission components and search for new supernova remnants in the complex. Multi-frequency radio continuum data from large-scale surveys are used to develop a new component separation method. Spectral analysis is done pixel by pixel for the non-thermal synchrotron emission with a realistic spectral index distribution and a fixed spectral index of beta = -2.1 for the thermal bremsstrahlung emission. With the new method, we separate the non-thermal and thermal components of the Cygnus X region at an angular resolution of 9.5arcmin. The thermal emission component is found to comprise 75% of the total continuum emission at 6cm. Thermal diffuse emission, rather than the discrete HII regions, is found to be the major contributor to the entire thermal budget. A smooth non-thermal emission background of 100 mK Tb is found. We successfully make the large-extent known supernova remnants and the HII regions embedded in the complex standing out, but no new large SNRs brighter than Sigma_1GHz = 3.7 x 10^-21 W m^-2 Hz^-1 sr^-1 are found.Comment: 9 pages, 5 figures, accepted by A&A. The quality of the figures is reduced due to file size limit of the websit