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The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has the largest aperture and a 19-beam L-band receiver, making it powerful for investigating the neutral hydrogen atomic gas (H i ) in the universe. We present HiFAST ( https://hifast.readthedocs.io ), a dedicated, modular, and self-contained calibration and imaging pipeline for processing the H i data of FAST. The pipeline consists of frequency-dependent noise diode calibration, baseline fitting, standing wave removal using an FFT-based method, flux density calibration, stray radiation correction, and gridding to produce data cubes. These modules can be combined as needed to process the data from most FAST observation modes: tracking, drift scanning, On-The-Fly mapping, and most of their variants. With HiFAST, the root-mean-square (RMS) noises of the calibrated spectra from all 19 beams were only slightly (∼5%) higher than the theoretical expectation. The results for the extended source M33 and the point sources are consistent with the results from Arecibo. The moment maps (0, 1 and 2) of M33 agree well with the results from the Arecibo Galaxy Environment Survey (AGES) with a fractional difference of less than 10%. For a common sample of 221 sources with signal-to-noise ratio S/N > 10 from the Arecibo Legacy Fast ALFA (ALFALFA) survey, the mean value of fractional difference in the integrated flux density, S int , between the two datasets is approximately 0.005%, with a dispersion of 15.4%. Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects ( S int > 2.5 Jy km s −1 ) is less than 5%. Our tests suggest that the FAST telescope, with the efficient, precise, and user-friendly pipeline HiFAST, will yield numerous significant scientific findings in the investigation of the H i in the universe.

Fuel economy has long been the core control objective in the energy management strategies of extended-range electric vehicles (EREVs), but little research has considered real driving emissions. In this paper, the real driving emissions of an EREV are investigated, and the abnormal pollutant emissions caused by engine start–stop events are clarified. Accordingly, an interpolated-startup-corrected method is proposed to construct real driving emission models. Next, an optimization problem is constituted with real driving emissions as the constraints and fuel consumption as the objective. The optimization problem is solved using a dynamic programming (DP) algorithm embodying the interpolated-startup-corrected emission models, and the start–stop reduction strategies and condition migration strategies are derived. Compared to the strategy without the emission constraints, the CO and NOx emissions under the no-start–stop strategy are cut down by about 70%; the PN emissions are even orders of magnitude lower. Meanwhile, the condition migration strategy can compromise the fuel economy and pollutant emissions by adjusting the engine operating points, thus possibly limiting pollutant emissions beyond the start–stop reduction strategy.

Micro reciprocating piston internal combustion engines are potentially desirable for high-energy density micro power sources. However, complex subsystem functions hinder the downsizing of reciprocating piston internal combustion engines. The homogeneous charge compression-ignition (HCCI) combustion mode requires no external ignition system; it contributes to structural simplification of the reciprocating piston internal combustion engines under a micro space constraint but has not been adequately verified at the millimeter scale. The study used a millimeter-scale HCCI reciprocating piston internal combustion engine fueled by a mixture of kerosene, ether, castor oil, and isopropyl nitrate for combustion investigation. The test engine with a displacement of 0.547 cc is the smallest reciprocating piston internal combustion engine known to have undergone in-cylinder combustion diagnosis. It is observed that the HCCI combustion mode at the millimeter scale can realize stable combustion with excellent cooperation for the thermodynamic cycle under appropriate structural and operating conditions, which is essentially not inferior to those in conventional-sized reciprocating piston internal combustion engines. This finding helps the next step of scaling down reciprocating piston internal combustion engines.

Pulsar hulling is a phenomenon of sudden cessation of pulse emission for a number of periods. The nulling fraction was often used to characterize the phenomenon. We propose a new method to analyse pulsar hulling phenomenon, by involving two key parameters, the nulling degree, X, which is defined as the angle in a rectangular coordinates for the numbers of nulling periods and bursting periods, and the nulling scale, N, which is defined as the effective length of the consecutive nulling periods and bursting periods. The nulling degree X can be calculated by tanX = Nnulling/Nbursting and the mean is related to the nulling fraction, while the nulling scale, N, is also a newly defined fundamental parameter which indicates how often the nulling occurs. We determined the distributions ofx and N for 10 pulsars by using the data in literature. We found that the nulling degree X indicates the relative length of nulling to that of bursting, and the nulling scale N is found to be related to the derivative of rotation frequency and hence the loss rate of rotational energy of pulsars. Their deviations reflect the randomness of the nulling process.

Clusters of galaxies have a huge mass which can act as gravitational lenses.Galaxies behind clusters can be distorted by the lenses to form arcs in images.Herein a search was done for giant lensed arcs using the SDSS data.By visually inspecting SDSS images of newly identified clusters in the SDSS DR8 and Stripe 82 data,we discover 8 strong lensing clusters together with additional 3probable and 6 possible cases.The lensed arcs show bluer colors than the member galaxies of clusters.The masses and optical luminosities of galaxy clusters interior to the arcs are calculated.The mass-to-light ratios are found to be in the range of a few tens of M⊙/L⊙,consistent with the distribution of previously known lensing clusters.

The survey data of Wide-field Infrared Survey Explorer （WISE） provide an opportunity for the identification of galaxy clusters. We present an efficient method for detecting galaxy clusters by combining the WISE data with SuperCOSMOS and 2MASS data. After performing star-galaxy separation, we calculate the number of companion galaxies around the galaxies with photometric redshifts previously estimated by the SuperCOSMOS, 2MASS and WISE data. A scaled richness Rscal ≥30 is set as a criterion to identify clusters. From a sky area of 275 deg2 of the Sloan Digital Sky Survey Stripe 82 region, we identify 302 clusters in the redshift range of 0.1 〈 z 〈 0.35, 247 （82%） of which are previously known SDSS clusters. The results suggest that our method is efficient for identifying galaxy clusters by using the all sky data of the SuperCOSMOS, 2MASS and WISE.

Repeated scatterings of unpolarized photons by non-relativistic electrons in a static and uniform magnetic field are investigated by using the Boltzmann equation with quantum mechanical correction factors for the stimulated scattering effects. The resulting Kompaneets equation depends explicitly on the electron cyclotron frequency and the incidence angle of the incoming photons relative to the direction of the magnetic field. The evolutionary behavior of the photon spectrum and energy density is highly anisotropic with respect to the static external magnetic field. Possible applications of our results to the X-ray emission from compact and massive stellar objects are discussed in detail and those to the interaction of the microwave background radiation with the hot electrons in galactic clusters are discussed briefly.

Objective: To investigate the clinical symptoms and conduct an epidemiological survey of early-onset severe obesity among children and adolescents in Qinhuangdao City of China from 2022 to 2023. Methods: This was a retrospective study two-hundred and fifty children and adolescents diagnosed with early-onset severe obesity from August 2022 to August 2023 at Maternity & Child Care Center of Qinhuangdao were selected as subjects; additionally, two-hundred and fifty cases of healthy children and adolescents undergoing routine medical examinations in the same period were selected as the non-obese group in a 1:1 ratio. Logistic regression analysis was employed to identify factors associated with the occurrence of early-onset severe obesity among children and adolescents. Results: Predominantly, early-onset severe obesity was observed in individuals aged over 14 years, females, those from families with a monthly income per capita of 5000 RMB, and children of obese parents or parents with lower educational levels. The binary logistic regression model identified several significant predictors of severe obesity, including parental obesity, maternal education level (junior high school and above), paternal education level (junior high school and above), non-picky eating habits, eating speed (faster), eating habits, daily outdoor activity duration (>1 hour), and average daily sleep duration (>8 hours) (p<0.05). Conclusion: Parental obesity, maternal education level (junior high school and above), paternal education level (junior high school and above), eating habits, daily outdoor activity duration (>1 hour), and average daily sleep duration (>8 hours) may be significant factors influencing the occurrence of severe obesity in children and adolescents. doi: https://doi.org/10.12669/pjms.41.5.10287 How to cite this: Wang M, Tian D, Han J, Chen N, Wu H. Clinical symptoms and epidemiological survey of early-onset severe obesity among children and adolescents. Pak J Med Sci. 2025;41(5):1499-1505. doi: https://doi.org/10.12669/pjms.41.5.10287 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Brightest Cluster Galaxies (BCGs) are mostly elliptical galaxies and very rarely have prominent star formations. We found that five out of 8,812 BCGs are E+A (i.e., post-starburst) galaxies, having an H δ absorption line with an equivalent width >2.5 Å and no distinct emission lines in [O II] and H α − . The E+A features we identified from the BCGs for the first time are not as significant as those in general galaxies, indicating that historically the star formations were not very violent.

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the most sensitive radio telescope for pulsar observations. We make polarimetric measurements of a large number of faint and distant pulsars using the FAST. We present the new measurements of Faraday rotation for 134 faint pulsars in the Galactic halo. Significant improvements are also made for some basic pulsar parameters for 15 of them. We analyse the newly determined rotation measures (RMs) for the Galactic magnetic fields by using these 134 halo pulsars, together with previously available RMs for pulsars and extragalactic radio sources and also the newly determined RMs for another 311 faint pulsars which are either newly discovered in the project of the Galactic Plane Pulsar Snapshot (GPPS) survey or previously known pulsars without RMs. The RM tomographic analysis in the first Galactic quadrant gives roughly the same field strength of around 2 µG for the large-scale toroidal halo magnetic fields. The scale height of the halo magnetic fields is found to be at least 2.7 ± 0.3 kpc. The RM differentiation of a large number of pulsars in the Galactic disk in the Galactic longitude range of 26° < l < 90° gives evidence for the clockwise magnetic fields (viewed from the north Galactic pole) in two interarm regions inside the Scutum arm and between the Scutum and Sagittarius arm, and the clockwise fields in the Local-Perseus interarm region and field reversals in the Perseus arm and beyond.