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The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Suicide-related behaviours are common in schizophrenia and are significantly associated with premature death. The objective of this meta-analysis study was to estimate the pooled prevalence of suicide-related behaviours in schizophrenia patients in China.
The relevant literature was searched systematically via the relevant electronic databases (PubMed, Embase, PsycINFO, Chinese National Knowledge Infrastructure, Wanfang Databases and Chinese Biological Medical Literature Database) from their inception until 14 September 2016. Only original studies that reported the prevalence of suicide-related behaviours including suicidal ideation (SI), suicide plan, suicide attempt (SA) and completed suicide were selected.
Nineteen articles met the inclusion criteria and were analysed. The pooled lifetime prevalence of SI and SA were 25.8% (95% CI 14.7–41.1%) and 14.6% (95% CI 9.1–22.8%), respectively. The 1-month prevalence of SI was 22.0% (95% CI 18.2–26.4%). Subgroup analyses of lifetime SI and SA showed that gender, sample size, survey year, study location and source of patients have no significant mediating effects on the results.
Suicide-related behaviours are common in Chinese schizophrenia patients. Due to the high mortality risk, regular screening and effective suicide prevention programmes are warranted.
Using the spectroscopic distances of over 0.12 million A-type stars selected from the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC), we map their three-dimensional number density distributions in the Galaxy. These stellar number density maps allow an investigation of the Galactic young age thin disk structure with no a priori assumptions about the functional form of its components. The data show strong evidence for a significant flaring young disk. A more detail analysis show that the stellar flaring have different behaviours between the Northern and the Southern Galactic disks. The maps also reveal spatially coherent, kpc-scale stellar substructure in the thin disk. Finally, we detect the Perseus arm stellar overdensity at R ~ 10 kpc.
Using the data from the LAMOST Galactic spectroscopic surveys and some other surveys, we have started a series of work to measure the mass distribution of our Galaxy. As a result of the first-stage, we have constructed the Galactic rotation curve out to 100 kpc and the Galactic escape velocity curve between 5 and 14 kpc. From the two curves, we have built parametrized mass models for our Galaxy, respectively. Both models yield a similar result for the Milky Way's virial mass: ~ 0.9 × 1012 M⊙.
A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.
The analysis method is developed to obtain dynamic characteristics of the rotating cantilever plate with thermal shock and tip-rub. Based on the variational principle, equations of motion are derived considering the differences between rubbing forces in the width direction of the plate. The transverse deformation is decomposed into quasi-static deformation of the cantilever plate with thermal shock and dynamic deformation of the rubbing plate under thermal shock. Then deformations are obtained through the calculation of modal characteristics of rotating cantilever plate and temperature distribution function. Special attention is paid to the influence of tip-rub and thermal shock on the plate. The results show that tip-rub has the characteristics of multiple frequency vibrations, and high frequency vibrations are significant. On the contrary, thermal shock shows the low frequency vibrations. The thermal shock makes the rubbing plate gradually change into low frequency vibrations. Because rub-induced vibrations are more complicated than those caused by thermal shock, tip-rub is easier to result in the destruction of the blade. The increasing friction coefficient intensifies vibrations of the rubbing plate. Minimizing friction coefficients can be an effective way to reduce rub-induced damage through reducing the surface roughness between the blade tip and the inner surface of the casing.
A high-order finite difference scheme has been developed to approximate the spatial derivative terms present in the unsteady Poisson-Nernst-Planck (PNP) equations and incompressible Navier-Stokes (NS) equations. Near the wall the sharp solution profiles are resolved by using the combined compact difference (CCD) scheme developed in five-point stencil. This CCD scheme has a sixth-order accuracy for the second-order derivative terms while a seventh-order accuracy for the first-order derivative terms. PNP-NS equations have been also transformed to the curvilinear coordinate system to study the effects of channel shapes on the development of electroos-motic flow. In this study, the developed scheme has been analyzed rigorously through the modified equation analysis. In addition, the developed method has been computationally verified through four problems which are amenable to their own exact solutions. The electroosmotic flow details in planar and wavy channels have been explored with the emphasis on the formation of Coulomb force. Significance of different forces resulting from the pressure gradient, diffusion and Coulomb origins on the convective electroosmotic flow motion is also investigated in detail.
To cope with phosphorus (P) deficiency, plants adapt root morphology to enhance inorganic P (Pi) acquisition from soil by allocating more biomass to roots, but whether the responses can be modified across gradients of P supply is not fully understood. The present study examined changes in root-length density (RLD), root-hair density (RHD) and root-hair length (RHL) of wheat (Triticum aestivum L.) in two contrasting soils, the Rough and Barnfield soils. Wheat plants were grown for 3 weeks in thin-plate rhizotrons in two soils with additions of 0, 10, 25, 50, 100 and 200 mg P/kg soil. Contrary to published literature, as P additions increased it was observed that a concomitant increase in RHL (250 to 1054 µm in the Rough soil and 303–1075 µm in the Barnfield soil) and RHD (57 to 122/mm in the Rough soil and 56–120/mm in the Barnfield soil), while RLD generally decreased (2480–1130 cm/cm3 in the Rough soil and 1716–865 cm/cm3 in the Barnfield soil). The levels of added P that resulted in critical P concentrations in the soils enabling maximum shoot biomass production were 50 mg/kg P in the Rough soil and 100 mg/kg P in the Barnfield soil, and these additions influenced root morphological changes. Under severe P deficiency, P supply increased RHL and RHD, but RLD was decreased. Improvement in lateral root and root-hair responses in wheat at extreme P deficiency may be a worthy target for breeding more sustainable genotypes for future agroecosystems.
We determined the prevalence and seasonality of infections by Fasciola of goats and bovine species (cattle and water buffalo) in Hubei and Anhui provinces of China. Faecal samples were collected at 2- to 3-month intervals from 200 goats in Hubei province and from 152 bovine species in Anhui province. All faecal samples were examined for the presence of parasites. We determined the nucleotide sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA (rDNA) of 39 Fasciola worms from Anhui province. The prevalence of Fasciola infection in goats ranged between 3.5 and 37.0%, with mean eggs per gram (EPG) ranging between 29.0 and 166.0. Prevalence and EPG exhibited downward trends over time with significant differences. The prevalence of Fasciola infection in cattle ranged between 13.3 and 46.2% (mean EPG, 36.4–100.0), and that of water buffalo ranged between 10.3 and 35.4% (mean EPG, 25.0–89.6), with a higher prevalence of infection and EPG from June to October compared with December to March. Analysis of ITS-1 and ITS-2 sequences revealed that F. hepatica and F. gigantica were present in all bovine species of Anhui province and that F. gigantica mainly infected water buffalo. This is the first demonstration of Fasciola infection in Hubei province and detection of F. hepatica and F. gigantica in Anhui province. The present study of Hubei province shows that mass treatment of livestock with closantel sodium injections in April and August/September controlled Fasciola infection effectively.
Mycoplasma infections are most frequently associated with disease in the urogenital or respiratory tracts and, in most cases, mycoplasmas infect the host persistently. In HIV-infected individuals the prevalence and role of genital mycoplasmas has not been well studied. To investigate the six species of Mycoplasma and the risk factors for infection in Jiangsu province, first-void urine and venous blood samples were collected and epidemiological questionnaires were administered after informed consent. A total of 1541 HIV/AIDS patients were recruited in this study. The overall infection rates of six Mycoplasma species were: Ureaplasma urealyticum (26·7%), Mycoplasma hominis (25·3%), M. fermentans (5·1%), M. genitalium (20·1%), M. penetrans (1·6%) and M. pirum (15·4%). The Mycoplasma infection rate in the unmarried group was lower than that of the married, divorced and widowed groups [adjusted odds ratio (aOR) 1·432, 95% confidence interval (CI) 1·077–1·904, P < 0·05]. The patients who refused highly active antiretroviral therapy (HAART) had a much higher risk of Mucoplasma infection (aOR 1·357, 95% CI 1·097–1·679, P < 0·05). Otherwise, a high CD4+ T cell count was a protective factor against Mycoplasma infection (aOR 0·576, 95% CI 0·460–0·719, P < 0·05). Further research will be required to confirm a causal relationship and to identify risk factors for Mycoplasma infection in HIV/AIDS populations.
Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well studied BL Lac through the whole electro-magnetic wavebands, it is violently variable in the optical bands. In the present work, we show its optical R band photometric observations carried out during the period of Nov. 2006 to Dec. 2012 using the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at Abastumani Observatory, Georgia. It shows a large variation of ΔR = 4.88 mag (14.20 - 19.08 mag) during our monitoring period. When periodicity analysis methods are adopted to its R observations from our Abastumani monitoring programme and those in the literature, the signs of some periods, P1 = 8.26 yr, P2 = 0.55 yr, P3 = 0.85 yr, P4 = 1.99 yr are found.
A complete dry processing route is developed for the fabrication of thermally-conductive carbon nanotube (CNT)-copper oxide (CuOx) heterostructures. This was achieved by the deposition of copper (Cu) onto CNTs and subsequent annealing in Ar and air environment to convert the coated Cu into CuOx nanoparticles. The survivability and diameters of CNTs were studied to ensure their integrity after the multiple processing steps and annealing temperatures (400 °C). The as-produced CNTs, air/Ar-annealed CNTs, Cu-coated CNTs, and CNT-CuOx heterostructures were characterized to study their structure, phase, and morphology using microscopy, elemental analysis, X-ray diffraction, and sheet resistance. It was observed that CNTs could survive the processing conditions and became coated with CuOx nanoparticles. The sheet resistance of CNTs coated with CuOx nanoparticles was ∼4 times greater than the as-produced CNTs. The Raman spectroscopy-based estimation of thermal conductivity of CNTs and CNT-CuOx heterostructures showed 2-7 times enhancement for the latter as compared to pure CuOx. In conclusion, such hybrid CNT-based heterostructures are promising for applications in thermal management.
Complex nanoscale architectures based on gold nanoparticles (AuNPs) can result in spatially-resolved plasmonics. Herein, we demonstrate the growth of silicon nanowires (SiNWs), heterostructures of SiNWs decorated with AuNPs, and SiNWs decorated with graphene shells encapsulated gold nanoparticles (GNPs). The fabrication approach combined CVD growth of nanowires and graphene with direct nucleation of AuNPs. The plasmonic or optical properties of SiNWs and their complex heterostructures were simulated using discrete dipole approximation method. Extinction efficiency spectra peak for SiNW significantly red-shifted (from 512 nm to 597 nm or 674 nm) after decoration with AuNPs, irrespective of the incident wave vector. Finally, SiNW decorated with GNPs resulted in incident wave vector-dependent extinction efficiency peak. For this case, wave vector aligned with the nanowire axial direction showed a broad peak at ∼535 nm. However, significant scattering and no peak was observed when aligned in radial direction of the SiNWs. Such spatially-resolved and tunable plasmonic or optical properties of nanoscale heterostructures hold strong potential for optical sensor and devices.
Vanadium oxides thin films with variable oxidation states have attracted great attention due to their unique electrical, optical properties and many important applications in microelectronics, infrared optical devices, and energy harvest systems. However, to fabricate vanadium oxide thin films with controllable phases and desired transport properties is still a challenge by using a chemical solution deposition (CSD) technique. In this paper, we report that vanadium oxide thin films with well controlled phases such as rhombohedral V2O3 and monoclinic VO2 could be synthesized on Al2O3 (0001) substrates using a CSD technique ---- polymer assisted deposition (PAD). Both V2O3 and VO2 thin films can be well controlled with good epitaxial quality by optimizing the fabrication parameters. The electrical resistivity changes 3∼4 orders of magnitude at metal insulator transition for both epitaxial V2O3 and VO2 thin films. The correlation between the physical properties and the microstructures of the films will be discussed.
With RXTE data ranging from 1997 August to 1998 May, we detected 8 type I X-ray bursts from the atoll source 4U 1735–44. The bursts are present at all the branches, and most occur at an inferred low mass accretion rate. We find no correlation between the peak flux of the bursts and the mass accretion rate. The results are different from that of 4U 1728-34, whose bursts' peak flux are anti-correlated with the mass accretion rate.
This study is an exploratory analysis for understanding the effect of a duodenal infusion of an α-linolenic acid (LNA) on the plasma and milk proteome of lactating dairy cows. Four primiparous Holstein cows were fitted with duodenal cannulas and received 0, 100, 200, 300 and 400 g/day of LNA in a two-treatment crossover design. Blood and milk were collected for determination of protein composition by two-dimensional gel electrophoresis. Alteration of protein spots was detected and identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS). Plasma haptoglobin levels, and milk β-casein A2, αs1-casein variant and albumin, did not differ in cows after infusion of 0, 100, 200 and 300 g/day of LNA, but were increased after the cows received duodenal infusion of 400 g/day of LNA. Western blot analysis of haptoglobin expression in plasma confirmed the alterations in protein expression seen using MS. This study demonstrated that infusion of high doses of LNA by duodenal cannula can result in metabolic stress within the bovine intestine and in changes in milk composition.
In members of the Bocavirus genus, that contain three open reading frames (ORFs) of the Parvovirinae subfamily, porcine bocaviruses (PoBoVs) exhibit the most genetic diversity. Based on the ORF2-encoded viral protein (VP1) classification, the six reported porcine bocaviruses were grouped into four species: PoBoV1 (porcine boca-like virus or PBoLV), PoBoV2 (porcine parvovirus 4 or PPV4), PoBoV3 (PBoV1/PBoV2) and PoBoV4 (6V/7V), with PoBoV3 and PoBoV4 each having two genotype viruses. All four PoBoV species were detected in the 166 samples collected in 2010 from swine herds located in ten provinces of China. The detection rates for PoBoV1-4 were 28·9%, 6·6%, 19·3% and 39·7%, respectively. The co-infection combinations involving these six porcine bocaviruses in the collected samples were very complex. Furthermore, mixed infections with viruses from other families (porcine reproductive and respiratory syndrome virus, classic swine fever virus and porcine circovirus type 2) were also detected.
We present a study on the liquid/solid interface, which can be electrostatically doped to a high carrier density (n~1014 cm-2) by electric-double-layer gating. Using micro-cleavage technique on the layered materials: ZrNCl and graphene, atomically flat channel surfaces can be easily prepared. Intrinsic high carrier density transport regime is accessed at the channel interface of electric double-layer field effect transistor, where novel transport properties are unveiled as the field-induced superconductivity on the ZrNCl with high transition temperature at 15 K, and accessing a high carrier density up to 2×1014 cm-2 in graphene and its multi-layers.
Ion-beam irradiation shows enhancement or degradation of magnetic properties on L10 phase of FePt and PtMn films. A highly ordered L10 FePt phase was directly achieved by using 2 MeV He-ion irradiation without conventional postannealing. The in-plane coercivity greater than 5700 Oe can be obtained after disordered FePt films were irradiated at the beam current of several μA/cm2 with the ion does of 2.4×1016 ions/cm2. The high beam-current-density results in direct beam heating on samples. In addition, the irradiation-induced heating process provides efficient microscopic energy transfer and creates excess point defects, which significantly enhances the diffusion and promotes the formation of the ordered phase. Consequently, the direct ordering of FePt took place by using ion-irradiation heating at temperature as low as 230°C. The comparison has been made on the [Fe/Pt]10/C films by RTA and high current-density He irradiation. Although RTA and ion irradiation both reach high coercivity, ion irradiation seems to suppress the (001) texture, leading to isotropic Hc. Ion-beam irradiation can also be applied to the transformation of PtMn. An ordered PtMn phase, a large exchange field and a high GMR ratio (11%) were obtained in PtMn-based spin valves by using 1.25 μA/cm2 He-ions. On the other hand, Ge-ion and O-ion irradiation completely destroyed the ferromagnetism of FePt and GMR of PtMn-based spin valves, respectively. We propose a novel approach to achieve magnetic patterning by using ion irradiation, which can be applied for patterned media and magnetic sensors.
Currently, there are a variety of techniques to deposit metal thin films ranging from high vacuum techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), through to solution methods like sol-gel. While the vacuum techniques can be limited by size and cost, sol-gel can be limited be the availability of appropriate precursors. All of these techniques have the further limitation that they cannot be used to coat porous materials conformally.
Polymer assisted deposition (PAD) addresses some of the limitations of sol-gel and costs of high vacuum techniques. PAD utilizes an aqueous polymer to bind a metal or metal complex that serves both to encapsulate the metal to prevent chemical reaction and maintain an even distribution of the metal in solution. Another advantage that PAD has is that the same solution can be used as precursors for the growth of metal oxide or reduced metal films. Herein, we report on the utility of PAD in preparing metal oxide films used to conformally coat porous material and reduced metal films.