Interpreting time-integrated polarization data of gamma-ray burst prompt emission

Aims. With the accumulation of polarization data in the gamma-ray burst (GRB) prompt phase, polarization models can be tested. Methods. We predicted the time-integrated polarizations of 37 GRBs with polarization observation. We used their observed spectral parameters to do this. In the model, the emission mechanism is synchrotron radiation, and the magnetic field configuration in the emission region was assumed to be large-scale ordered. Therefore, the predicted polarization degrees (PDs) are upper limits. Results. For most GRBs detected by the Gamma-ray Burst Polarimeter (GAP), POLAR, and AstroSat, the predicted PD can match the corresponding observed PD. Hence the synchrotron-emission model in a large-scale ordered magnetic field can interpret both the moderately low PDs ($\sim10\%$) detected by POLAR and relatively high PDs ($\sim45\%$) observed by GAP and AstroSat well. Therefore, the magnetic fields in these GRB prompt phases or at least during the peak times are dominated by the ordered component. However, the predicted PDs of GRB 110721A observed by GAP and GRB 180427A observed by AstroSat are both lower than the observed values. Because the synchrotron emission in an ordered magnetic field predicts the upper-limit of the PD for the synchrotron-emission models, PD observations of the two bursts challenge the synchrotron-emission model. Then we predict the PDs of the High-energy Polarimetry Detector (HPD) and Low-energy Polarimetry Detector (LPD) on board the upcoming POLAR-2. In the synchrotron-emission models, the concentrated PD values of the GRBs detected by HPD will be higher than the LPD, which might be different from the predictions of the dissipative photosphere model. Therefore, more accurate multiband polarization observations are highly desired to test models of the GRB prompt phase.Comment: 6 pages, 5 figures, with updated AstroSat data, accepted by A

Seasonal and diurnal variations of atmospheric mercury across the US determined from AMNet monitoring data

Speciated atmospheric mercury observations collected over the period from 2008 to 2010 at the Environmental Protection Agency and National Atmospheric Deposition Program Atmospheric Mercury Network sites (AMNet) were analyzed for its spatial, seasonal, and diurnal characteristics across the US. Median values of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury (PBM) at 11 different AMNet sites ranged from 148–226 ppqv (1.32–2.02 ng m<sup>−3</sup>), 0.05–1.4 ppqv (0.47–12.4 pg m<sup>−3</sup>) and 0.18–1.5 ppqv (1.61–13.7 pg m<sup>−3</sup>), respectively. Common characteristics of these sites were the similar median levels of GEM as well as its seasonality, with the highest mixing ratios occurring in winter and spring and the lowest in fall. However, discernible differences in monthly average GEM were as large as 30 ppqv, which may be caused by sporadic influence from local emission sources. The largest diurnal variation amplitude of GEM occurred in the summer. Seven rural sites displayed similar GEM summer diurnal patterns, in that the lowest levels appeared in the early morning, and then the GEM mixing ratio increased after sunrise and reached its maxima at noon or in the early afternoon. Unlike GEM, GOM exhibited higher mixing ratios in spring and summer. The largest diurnal variation amplitude of GOM occurred in spring for most AMNet sites. The GOM diurnal minima appeared before sunrise and maxima appeared in the afternoon. The increased GOM mixing ratio in the afternoon indicated a photochemically driven oxidation of GEM resulting in GOM formation. PBM exhibited diurnal fluctuations in summertime. The summertime PBM diurnal pattern displayed daily maxima in the early afternoon and lower mixing ratios at night, implying photochemical production of PBM in summer

A multiple exp-function method for nonlinear differential equations and its application

A multiple exp-function method to exact multiple wave solutions of nonlinear partial differential equations is proposed. The method is oriented towards ease of use and capability of computer algebra systems, and provides a direct and systematical solution procedure which generalizes Hirota's perturbation scheme. With help of Maple, an application of the approach to the $3+1$ dimensional potential-Yu-Toda-Sasa-Fukuyama equation yields exact explicit 1-wave and 2-wave and 3-wave solutions, which include 1-soliton, 2-soliton and 3-soliton type solutions. Two cases with specific values of the involved parameters are plotted for each of 2-wave and 3-wave solutions.Comment: 12 pages, 16 figure

Approximation of conformal mappings by circle patterns

A circle pattern is a configuration of circles in the plane whose combinatorics is given by a planar graph G such that to each vertex of G corresponds a circle. If two vertices are connected by an edge in G, the corresponding circles intersect with an intersection angle in $(0,\pi)$. Two sequences of circle patterns are employed to approximate a given conformal map $g$ and its first derivative. For the domain of $g$ we use embedded circle patterns where all circles have the same radius decreasing to 0 and which have uniformly bounded intersection angles. The image circle patterns have the same combinatorics and intersection angles and are determined from boundary conditions (radii or angles) according to the values of $g'$ ($|g'|$ or $\arg g'$). For quasicrystallic circle patterns the convergence result is strengthened to $C^\infty$-convergence on compact subsets.Comment: 36 pages, 7 figure

Constraints on the phase γ\gamma and new physics from B→KπB\to K\pi Decays

Recent results from CLEO on $B\to K\pi$ indicate that the phase $\gamma$ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that $\gamma$ extracted using $B\to K\pi, \pi\pi$ is sensitive to new physics occurring at loop level. It provides a powerful method to probe new physics in electroweak penguin interactions. Using effects due to anomalous gauge couplings as an example, we show that within the allowed ranges for these couplings information about $\gamma$ obtained from $B\to K \pi, \pi\pi$ can be very different from the Standard Model prediction.Comment: Revised version with analysis done using new data from CLEO. RevTex, 11 Pages with two figure

Effects of the bonded component heights on the stress intensity factors of the edge interface cracks

The height of the bonded component of a bonded strip changes with the scope of requirements in practical applications. Therefore, one must understand the effect of the influence of the height of the bonded component. In this research, the stress intensity factors of an edge-cracked asymmetrically bonded strip are systematically computed using the proportional crack tip opening displacement method based on FE analysis. Then, the stress intensity factors are compared for arbitrary sets of material combinations in the whole range of Dundurs\u27 material space with varying the height of the bonded component, and the combined effects of the relative height of the bonded component and material combinations on the stress intensity factors are discussed for the typical engineering materials.2018 5th Global Conference on Polymer and Composite Materials (PCM 2018), 10–13 April, 2018, Kitakyushu City, Japa

Confined Interfacial Monomicelle Assembly for Precisely Controlled Coating of Single-Layered Titania Mesopores

The development of core-shell structures has been in great demand recently owing to their integrated functionalities. However, the progress in reliable coating of porous semiconductors remains unproductive. Here, we have demonstrated a confined interfacial monomicelle assembly method for controlled coating of ordered single-layered mesoporous TiO2. The coating method can be well controlled with tunable coated layers, mesopore size, and switchable coated surfaces. The resulting mesoporous TiO2 exhibit excellent electrochemical properties as a sodium-ion anode, which is attributed to their unique mesostructures associated with accessible high surface area and ultrathin layers. Such accurately designed mesoporous core-shell nanostructures are expected to provide a useful platform to produce numerous delicate core-shell nanostructures with integrated functionalities and mesoporosities for potential applications, such as catalysts, sensors, energy storage, and energy conversion. - 2019 Elsevier Inc.Mesoporous core-shell nanostructures have recently been receiving extensive scientific interest; however, reliable approaches for coating mesoporous materials still remain exciting challenges, except for amorphous silica. We report, for the first time, a confined interfacial monomicelle assembly method for controlled coating of anatase TiO2 with single-layered ordered mesopores on diverse surfaces, opening up the area of coating ordered mesoporous crystalline materials that possess mesopores originating from self-assembled surfactant instead of accumulated nanocrystals. This facile and repeatable methodology relies on the solvent-confinement effect of glycerol during the assembly process and monomicelle hydrogel preformation by selective evaporation of double-solvent precursors. This assembly process shows precise controllability and great versatility, endowing the coated TiO2 layers with highly tunable thickness, mesopore size, and switchable coated surfaces. The ultrathin monolayered mesopores of such mesoporous TiO2 shells, in combination with their high surface area and highly crystalline nature, afford them excellent rate capability and superior cyclability for sodium-ion storage. - 2019 Elsevier Inc.We have demonstrated a confined interfacial monomicelle assembly approach for accurately coating ordered monolayered TiO2 mesopores on diverse surfaces. By regulating the synthetic conditions, the coated mesoporous TiO2 layers can be well controlled with desired thickness, mesopore size, and switchable coated surfaces. The resulting monolayered mesoporous TiO2 exhibit excellent sodium-storage properties. This unique mesoporous TiO2 coating strategy affords great potential in constructing multicomponent nanostructures with mesoporosities for advanced technologies. - 2019 Elsevier Inc.This work is supported by the State Key Basic Research Program of China ( 2017YFA0207303 ), the National Natural Science Foundation of China ( 21733003 ), the Shanghai Leading Academic Discipline Project ( B108 ), and the Science and Technology Commission of Shanghai Municipality ( 17JC1400100 ). K.L. acknowledges the financial support by the China Scholarship Council ( 201806100112 ). A.E. acknowledges Qatar University under GCC Co-Fund Program grant GCC-2017-001

Case report: Whole genome sequencing based investigation of maternal-neonatal listeriosis in Sichuan, China

Background: Neonatal listeriosis is a rare but severe disease manifesting as septicemia and central nervous system (CNS) infections with a high fatality rate of around 20 to 30%. Whole genome sequencing (WGS) is a promising technique for pathogen identification and infection source tracing with its high resolution. Case presentation: A case of neonatal sepsis with listeriosis was reported with positive blood culture for Listeria monocytogenes. The case was investigated to confirm the vertical transmission of the infection and identify the potential food source of the maternal L. monocytogenes infection using WGS. L. monocytogenes was isolated from the neonate's blood sample the day after caesarean delivery and from the mother's genital and pudenda swab samples 5 days and 13 days after caesarean delivery. WGS showed that the isolate from the neonate was identical to the genome type of the isolates from the mother, with only one of the 4 isolates from the mother differing by one single nucleotide polymorphism (SNP). By WGS, one L. monocytogenes isolate from a ready-to-eat (RTE) meat sample in the patients' community market shared the same sequence type but was ruled out as the cause of infection, with 57 SNP differences to the strain causing the maternal-neonatal infection. The food isolate also carried a novel plasmid pLM1686 that harbored heavy metal resistance genes. After caesarean section, the mother was treated with a third generation cephalosporin which L. monocytogenes is naturally resistant to, which may explain why genital and pudenda swabs were still culture-positive for L. monocytogenes 13 days after delivery. Conclusions: Genital swab culture for L. monocytogenes had been informative in the diagnosis of maternal listeriosis in this case. The high resolution of WGS confirmed the maternal-neonatal transmission of L. monocytogenes infection and ruled out the L. monocytogenes contaminated RTE meat from the local market as the direct source of the mother's infection

Single-molecule force spectroscopy quantification of adhesive forces in cucurbit[8]uril host-guest ternary complexes.

Cucurbit[8]uril (CB[8]) heteroternary complexes display certain characteristics making them well-suited for molecular level adhesives. In particular, the ability to control adhesion through careful choice of host-guest binding pairs enables specific, fully reversible adhesion. Understanding the effect of the environment on the adhesive system is also critical when developing new molecular level adhesives. Here we explore the binding forces involved in the methyl viologen · CB[8] · napthol heteroternary complex using single-molecule force spectroscopy (SMFS) under a variety of conditions. From SMFS, the interaction of a single ternary complex was found to be in the region of 140 pN. Additionally, a number of surface interactions could be readily differentiated using the SMFS technique allowing for a deeper understanding of the dynamic heteroternary CB[8] system on the single-molecule scale.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC), the Walters-Kundert Charitable Trust and an ERC Starting Investigator grant (ASPiRe, 240629). ZWK, ERJ, YL thank the Royal Society of Chemistry for a grant allowing travel to Tsinghua University to carry out this research. YY would like to acknowledge financial support from the Young Scientists of the National Science Foundation of China (21304052). YL thanks the Chinese Overseas Scholarship Trust for financial support. JdB thanks the Marie Curie Actions program for financial support. PEW thanks the Atomic Weapons and Energy Commission and the Melville Laboratory for Polymer Synthesis for financial support