As a major component of the LAMOST Galactic surveys, the LAMOST Spectroscopic Survey of the Galactic Anticentre (LSS-GAC) aims to survey a significant volume of the Galactic thin/thick discs and halo ...for a contiguous sky area of over 3400 deg2 centred on the Galactic anticentre (|b| ≤ 30°, 150 ≤ l ≤ 210°), and obtain λλ3700–9000 low-resolution (R ∼ 1800) spectra for a statistically complete sample of ∼3 M stars of all colours down to a limiting magnitude of r ∼ 17.8 mag (to 18.5 mag for limited fields). Together with Gaia, the LSS-GAC will yield a unique data set to advance our understanding of the structure and assemblage history of the Galaxy, in particular its disc(s). In addition to the main survey, the LSS-GAC will also target hundreds of thousands objects in the vicinity fields of M 31 and M 33 and survey a significant fraction (over a million) of randomly selected very bright stars (r ≤ 14 mag) in the Northern hemisphere. During the Pilot and the first year Regular Surveys of LAMOST, a total of 1042 586 750 867 spectra of a signal-to-noise ratio S/N(7450 Å) ≥ 10 S/N(4650 Å) ≥ 10 have been collected. In this paper, we present a detailed description of the target selection algorithm, survey design, observations and the first data release of value-added catalogues (including radial velocities, effective temperatures, surface gravities, metallicities, values of interstellar extinction, distances, proper motions and orbital parameters) of the LSS-GAC.
Abstract
We present the second release of value-added catalogues of the LAMOST Spectroscopic Survey of the Galactic Anticentre (LSS-GAC DR2). The catalogues present values of radial velocity Vr, ...atmospheric parameters – effective temperature Teff, surface gravity log g, metallicity Fe/H, α-element to iron (metal) abundance ratio α/Fe (α/M), elemental abundances C/H and N/H and absolute magnitudes MV and $M_{K_{\rm s}}$ deduced from 1.8 million spectra of 1.4 million unique stars targeted by the LSS-GAC since 2011 September until 2014 June. The catalogues also give values of interstellar reddening, distance and orbital parameters determined with a variety of techniques, as well as proper motions and multiband photometry from the far-UV to the mid-IR collected from the literature and various surveys. Accuracies of radial velocities reach 5 km s−1 for the late-type stars, and those of distance estimates range between 10 and 30 per cent, depending on the spectral signal-to-noise ratios. Precisions of Fe/H, C/H and N/H estimates reach 0.1 dex, and those of α/Fe and α/M reach 0.05 dex. The large number of stars, the contiguous sky coverage, the simple yet non-trivial target selection function and the robust estimates of stellar radial velocities and atmospheric parameters, distances and elemental abundances make the catalogues a valuable data set to study the structure and evolution of the Galaxy, especially the solar-neighbourhood and the outer disc.
We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China ...Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.
We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (mχ) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on ...time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in mχ are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σχNSI at 90% confidence level are derived as 2×10−32∼7×10−35 cm2 for TI analysis at mχ∼50–180 MeV/c2, and 3×10−32∼9×10−38 cm2 for AM analysis at mχ∼75 MeV/c2–3.0 GeV/c2.
Background
IL‐25 has been proposed to play a key role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the association of IL‐25 with the ...Th2‐biased inflammatory profiles in CRSwNP.
Methods
Nasal polyp (NP) tissues and control uncinate process tissues were collected from 92 patients with CRSwNP, 20 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 16 normal control subjects. IL‐25 expression was examined using immunohistochemistry and immunofluorescence staining, flow cytometry, RT‐qPCR, and ELISA. The inflammatory profiles and clinical characteristics of 2 NP subtypes (IL‐25high and IL‐25low) were evaluated, and the effects of IL‐25 on Th2 cytokine production in cultured dispersed polyp cells were examined in vitro.
Results
The mRNA and protein levels of IL‐25 were significantly increased in the polyp tissues compared with the control uncinate process tissues. The IL‐25high subtype showed greater computed tomography scores, endoscopic scores, and Th2 response. Exposure to IL‐25 activated type 2 innate lymphoid cells and Th2 cells in NP simultaneously which further increased Th2 cytokine production in vitro.
Conclusions
Local IL‐25 plays a crucial role in promoting Th2‐biased inflammatory profiles in NP and may serve as a promising therapeutic target in CRSwNP patients.
One of the most promising approaches to reach a high gain in inertial confinement fusion is the fast ignition scheme. In this scheme, a relativistic electron beam is generated; this passes through ...the imploded plasma and deposits parts of its energy in the core. However, the large angular spread of the relativistic electron beam and the poorly controlled compression of the target affect realization of the fast ignition technique. Here, we demonstrate that indirectly driven (that is, driven by X-rays generated inside a gold hohlraum) implosions with a ‘high-foot’ and a short-coast time of less than 200 ps allow us to tightly compress the shell. Furthermore, we show the ability to optimize the symmetry of the imploding shell by changing the hohlraum length, successfully tuning a suitable tube-shaped shell to compensate for the large angular spread of the relativistic electron beam and to enhance the electron-to-core coupling efficiency via resistive magnetic fields. Benefiting from those experimental techniques, a significant enhancement in neutron yield was achieved in our indirectly driven fast ignition experiments. These results pave the way towards high-coupling fast ignition experiments with indirectly driven targets similar to those at the National Ignition Facility.Experiments realizing the indirect-drive fast ignition scheme for inertial confinement fusion are reported. Enabled by a tightly compressed target, an increase of neutron yield is observed.
Adopting self‐healing, robust, and stretchable materials is a promising method to enable next‐generation wearable electronic devices, touch screens, and soft robotics. Both elasticity and ...self‐healing are important qualities for substrate materials as they comprise the majority of device components. However, most autonomous self‐healing materials reported to date have poor elastic properties, i.e., they possess only modest mechanical strength and recoverability. Here, a substrate material designed is reported based on a combination of dynamic metal‐coordinated bonds (β‐diketone–europium interaction) and hydrogen bonds together in a multiphase separated network. Importantly, this material is able to undergo self‐healing and exhibits excellent elasticity. The polymer network forms a microphase‐separated structure and exhibits a high stress at break (≈1.8 MPa) and high fracture strain (≈900%). Additionally, it is observed that the substrate can achieve up to 98% self‐healing efficiency after 48 h at 25 °C, without the need of any external stimuli. A stretchable and self‐healable dielectric layer is fabricated with a dual‐dynamic bonding polymer system and self‐healable conductive layers are created using polymer as a matrix for a silver composite. These materials are employed to prepare capacitive sensors to demonstrate a stretchable and self‐healable touch pad.
Dynamic metal‐coordinated bonds (β‐diketone–europium interaction) and hydrogen bonds, are combined in a multiphase separated network, in a new strategy to enable a robust and elastic capacitive sensor with autonomous self‐healing properties.
We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B ...experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.
A new alpha-emitting isotope U-214, produced by the fusion-evaporation reaction W-182(Ar-36,4n) U-214, was identified by employing the gas-filled recoil separator SHANS and the recoil-a correlation ...technique. More precise a-decay properties of even-even nuclei U-216,U-218 were also measured in the reactions of Ar-40, Ca-40 beams with W-180,W-182,W- 184 targets. By combining the experimental data, improved alpha-decay reduced widths delta(2) for the even-even Po-Pu nuclei in the vicinity of the magic neutron number N = 126 are deduced. Their systematic trends are discussed in terms of the N-p N-n scheme in order to study the influence of protonneutron interaction on a decay in this region of nuclei. It is strikingly found that the reduced widths of( 214,216)U are significantly enhanced by a factor of two as compared with the NpNn systematics for the 84 <= Z <= 90 and N < 126 even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the pi 1f (7/2) and nu 1f(5/2) spin-orbit partner orbits, which is supported by the large-scale shell model calculation.
Herein, we report a de novo chemical design of supramolecular polymer materials (SPMs-1–3) by condensation polymerization, consisting of (i) soft polymeric chains (polytetramethylene glycol and ...tetraethylene glycol) and (ii) strong and reversible quadruple H-bonding cross-linkers (from 0 to 30 mol %). The former contributes to the formation of the soft domain of the SPMs, and the latter furnishes the SPMs with desirable mechanical properties, thereby producing soft, stretchable, yet tough elastomers. The resulting SPM-2 was observed to be highly stretchable (up to 17 000% strain), tough (fracture energy ∼30 000 J/m2), and self-healing, which are highly desirable properties and are superior to previously reported elastomers and tough hydrogels. Furthermore, a gold, thin film electrode deposited on this SPM substrate retains its conductivity and combines high stretchability (∼400%), fracture/notch insensitivity, self-healing, and good interfacial adhesion with the gold film. Again, these properties are all highly complementary to commonly used polydimethylsiloxane-based thin film metal electrodes. Last, we proceed to demonstrate the practical utility of our fabricated electrode via both in vivo and in vitro measurements of electromyography signals. This fundamental understanding obtained from the investigation of these SPMs will facilitate the progress of intelligent soft materials and flexible electronics.
PDF
