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The Large sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio (SNR) ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters: late A,FGK-type stars with high quality spectra (1 061 918 entries), A-type stars (100 073 entries), and M-type stars (121 522 entries). This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.

Recently, the quest for new highly stretchable transparent tactile sensors with large-scale integration and rapid response time continues to be a great impetus to research efforts to expand the promising applications in human-machine interactions, artificial electronic skins, and smart wearable equipment. Here, a self-powered, highly stretchable, and transparent triboelectric tactile sensor with patterned Ag-nanofiber electrodes for detecting and spatially mapping trajectory profiles is reported. The Ag-nanofiber electrodes demonstrate high transparency (>70%), low sheet resistance (1.68-11.1 Ω □ ), excellent stretchability, and stability (>100% strain). Based on the electrode patterning and device design, an 8 × 8 triboelectric sensor matrix is fabricated, which works well under high strain owing to the effect of the electrostatic induction. Using cross-locating technology, the device can execute more rapid tactile mapping, with a response time of 70 ms. In addition, the object being detected can be made from any commonly used materials or can even be human hands, indicating that this device has widespread potential in tactile sensing and touchpad technology applications.

This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information about the FITS headers of spectra are also introduced. The released data set includes 319 000 spectra and a catalog of these objects.

We present estimates of stellar age and mass for 0.93 million Galactic disk main sequence turn-off and sub-giant stars from the LAMOST Galactic Spectroscopic Surveys. The ages and masses are determined by matching with stellar isochrones using Bayesian algorithm, utilizing effective temperature T eff , absolute magnitude M V , metallicity Gyr exhibit both the thin and thick disk sequences, while younger (older) stars show only the thin (thick) disk sequence, indicating that the thin disk became prominent 8-10 Gyr ago, while the thick disk formed earlier and almost quenched 8 Gyr ago. Stellar ages exhibit positive vertical and negative radial gradients across the disk, and the outer disk of R 9 kpc exhibits a strong flare in stellar age distribution.

Solution‐processed lead halide perovskites are considered one of the promising materials for flexible optoelectronics. However, the array integration of ultrathin flexible perovskite photodetectors (PDs) remains a significant challenge limited by the incompatibility of perovskite materials with manufacturing techniques involving polar liquids. Here, an ultrathin (2.4 µm) and conformable perovskite‐based PD array (10 × 10 pixels) with ultralight weight (3.12 g m−2) and excellent flexibility, is reported. Patterned all‐inorganic CsPbBr3 perovskite films with precise pixel position, controllable morphology, and homogenous dimension, are synthesized by a vacuum‐assisted drop‐casting patterning process as the active layer. The use of waterproof parylene‐C film as substrate and encapsulation layer effectively protects the perovskite films against penetration of polar liquids during the peeling‐off process. Benefitting from the encapsulation and ultrathin property, the device exhibits long‐term stability in the ambient environment, and robust mechanical stability under bending or 50% compressive strain. More importantly, the ultrathin flexible PD arrays conforming to hemispherical support realize imaging of light distribution, indicating the potential applications in retina‐like vision sensing.

As a major component of the LAMOST Galactic surveys, the LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC) aims to survey a significant volume of the Galactic thin/thick discs and halo for a contiguous sky area of over 3,400 deg 2 centred on the Galactic anti-centre (|b| 30• , 150 l 210 • ), and obtain λλ3700 -9000 low resolution (R ∼ 1, 800) spectra for a statistically complete sample of ∼ 3 M stars of all colours down to a limiting magnitued of r ∼ 17.8 mag (to 18.5 mag for limited fields). Together with Gaia, the LSS-GAC will yield a unique dataset to advance our understanding of the structure and assemblage history of the Galaxy, in particular its disk(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 (VB; r 14 mag) in the northern hemisphere. During the Pilot and the first year Regular Surveys of LAMOST, a total of 1,042,586 [750,867] spectra of a signal to noise ratio S/N(7450Å) 10 [S/N(4650Å) 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.

Accurate measurements of stellar metallicity gradients in the radial and vertical direction of the disk and their temporal variations provide important constraints of the formation and evolution of the Milky Way disk. We use 297 042 main sequence turn-off stars selected from the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC) to determine the radial and vertical gradients of stellar metallicity, ∆[Fe/H]/∆R, ∆[Fe/H]/∆|Z|, of the Milky Way disk in the anti-center direction. We determine ages of those turn-off stars by isochrone fitting and measure the temporal variations of metallicity gradients. We have carried out a detailed analysis of the selection effects resulting from the selection, observation and data reduction of LSS-GAC targets and the potential biases of a magnitude limited sample on the determinations of metallicity gradients. Our results show that the gradients, both in the radial and vertical directions, exhibit significant spatial and temporal variations. The radial gradients yielded by stars of oldest ages ( 11 Gyr) are essentially zero at all heights from the disk midplane, while those given by younger stars are always negative. The vertical gradients deduced from stars of oldest ages ( 11 Gyr) are negative and show only very weak variations with the Galactocentric distance in the disk plane, R, while those yielded by younger stars show strong variations with R. After being essentially flat at the earliest epochs of disk formation, the radial gradients steepen as age decreases, reaching a maxima (steepest) at age 7 -8 Gyr, and then they flatten again. Similar temporal trends are also found for the vertical gradients. We infer that the assemblage of the Milky Way disk may have experienced at least two distinct phases. The earlier phase is probably related to a slow, pressure-supported collapse of gas, when the gas settle down to the disk mainly in the vertical direction. In the later phase, there are significant radial flows of gas in the disk, and the rate of gas inflow near the solar neighborhood reaches a maximum around a lookback time of 7 -8 Gyr. The transition of the two phases occurs around a lookback time between 8 and 11 Gyr. The two phases may be responsible for the formation of the Milky Way thick and thin disks, respectively. And, as a consequence, we recommend that stellar age is a natural, physical criterion to distinguish thin and thick disk stars. From an epoch earlier than 11 Gyr to one between 8 and 11 Gyr, there is an abrupt, significant change in magnitude of both the radial and vertical metallicity gradients, suggesting that stellar radial migration is unlikely to play an important role in the formation of thick disk.