WISE Detection of the Galactic Low-Mass X-Ray Binaries

We report on the results from our search for the Wide-field Infrared Survey Explorer detection of the Galactic low-mass X-ray binaries. Among 187 binaries catalogued in Liu et al. (2007), we find 13 counterparts and two candidate counterparts. For the 13 counterparts, two (4U~0614+091 and GX~339$-$4) have already been confirmed by previous studies to have a jet and one (GRS~1915+105) to have a candidate circumbinary disk, from which the detected infrared emission arose. Having collected the broad-band optical and near-infrared data in literature and constructed flux density spectra for the other 10 binaries, we identify that three (A0620$-$00, XTE J1118+480, and GX 1+4) are candidate circumbinary disk systems, four (Cen X-4, 4U 1700+24, 3A 1954+319, and Cyg X-2) had thermal emission from their companion stars, and three (Sco X-1, Her X-1, and Swift J1753.5$-$0127) are peculiar systems with the origin of their infrared emission rather uncertain. We discuss the results and WISE counterparts' brightness distribution among the known LMXBs, and suggest that more than half of the LMXBs would have a jet, a circumbinary disk, or the both.Comment: 9 pages, 5 figures, submitted to Ap

WγW\gamma and ZγZ\gamma production and limits on anomalous WWγWW\gamma, ZZγZZ\gamma and ZγγZ\gamma\gamma couplings with D0 detector

The recent D0 results on Wgamma and Zgamma production are presented. First, the cross section and the difference in rapidities between photons and charged leptons for inclusive Wgamma production in egamma and mugamma final states are discussed, then are the cross section and differential cross section as a function of photon transverse momentum for Zgamma process. Finally, I present the limits on anomalous WWgamma, ZZgamma and Zgammagamma couplings.Comment: 18 pages, 16 figures, review articl

Near-Infrared Imaging of White Dwarfs with Candidate Debris Disks

We have carried out $JHK_s$ imaging of 12 white dwarf debris disk candidates from the WIRED SDSS DR7 catalog, aiming to confirm or rule out disks among these sources. On the basis of positional identification and the flux density spectra, we find that seven white dwarfs have excess infrared emission, but mostly at WISE W1 and W2 bands, four are due to nearby red objects consistent with background galaxies or very low mass dwarfs, and one exhibits excess emission at $JHK_s$ consistent with an unresolved L0 companion at the correct distance. While our photometry is not inconsistent with all seven excesses arising from disks, the stellar properties are distinct from the known population of debris disk white dwarfs, making the possibility questionable. In order to further investigate the nature of these infrared sources, warm Spitzer imaging is needed, which may help resolve galaxies from the white dwarfs and provide more accurate flux measurements.Comment: 9 pages, 3 figures, significant comments from Referee were incorporated, accepted for publication in Ap

Logic motif of combinatorial control in transcriptional networks

Combinatorial control is prevalent in transcriptional regulatory networks. However, whether there are specific logic patterns over- or under-represented in real networks remains uninvestigated. Using a theoretic model and _in-silico_ simulations, we systematically study how the relative abundance of distinct regulatory logic patterns influences the network’s global dynamics. We find that global dynamic characteristics are sensitive to several specific logic patterns regardless of the detailed network topology. We show it is possible to infer logic motifs based on the sensitivity profile and the biological interpretations of these global characteristics

Infrared Observations of The Millisecond Pulsar Binary J1023+0038: Evidence for Short-Term Nature of Its Interacting Phase in 2000--2001

We report our multi-band infrared (IR) imaging of the transitional millisecond pulsar system J1023+0038, a rare pulsar binary known to have an accretion disk in 2000--2001. The observations were carried out with ground-based and space telescopes from near-IR to far-IR wavelengths. We detected the source in near-IR JH bands and Spitzer 3.6 and 4.5 $\mu$m mid-IR channels. Combined with the previously-reported optical spectrum of the source, the IR emission is found to arise from the companion star, with no excess emission detected in the wavelength range. Because our near-IR fluxes are nearly equal to those obtained by the 2MASS all-sky survey in 2000 Feb., the result indicates that the binary did not contain the accretion disk at the time, whose existence would have raised the near-IR fluxes to 2-times larger values. Our observations have thus established the short-term nature of the interacting phase seen in 2000--2001: the accretion disk at most existed for 2.5 yrs. The binary was not detected by the WISE all-sky survey carried out in 2010 at its 12 and 22 $\mu$m bands and our Herschel far-IR imaging at 70 and 160 $\mu$m. Depending on the assumed properties of the dust, the resulting flux upper limits provide a constraint of <3x10^{22}--3x10^{25} g on the mass of the dust grains that possibly exist as the remnant of the previously-seen accretion disk.Comment: 7 page, 1 figure, 2 tables, accepted for publication in Ap

The impact on Chinese passenger airlines by including them in emission reduction schemes

Civil Aviation contributes to 2-3% of global total GHG emissions. Although it is a small share, the growth rate of aircraft emissions is faster than most industries in the world. Scientists and aircraft manufacture keen to find means to improve fuel efficiency and reduce aircraft emissions. However, technology innovation is not going to be achieved in the near future. Therefore, governments and international organisations placed their focus on policy instruments. This thesis selects China, the largest emitter in the world, as an example to study how emissions mitigation schemes could influence the airline industry. While there has been a spectacular growth in Chinese aviation in recent decades, driven by economic and population growth, limited research has focused on the consequential increase in carbon dioxide emissions from the Chinese aviation industry, which has grown on average by 12% per annum since 1986. Therefore, this research firstly examined historical drivers pushing aviation sector to grow; and then develops a range of empirical models of future aviation growth to explore the cost impact of emission abatement instruments on the growth and competitiveness of the Chinese aviation industry. By using flights between EEA countries and China as a case study, the thesis develops a more detailed region-paired demand model to project future growth of international aviation; and also compared discrete choice analysis with the market share model and myopic game theory to examine the impact on airline competition due to mitigation schemes. There are significant policy challenges in developing mitigation schemes for international aviation, which are explored in this thesis as well. The empirical analysis of the thesis provides a better understanding to policymakers about how to cooperate with developing countries and developed countries together in dealing with the issue of high volumes of aircraft emission