Explore the vast range of titles available.

We report the physical properties of the 18 brightest (S 870 μm = 12.4–19.2 mJy) and not strongly lensed 870 μm–selected dusty star-forming galaxies (DSFGs), also known as submillimeter galaxies (SMGs), in the COSMOS field. This sample is part of an ALMA band 3 spectroscopic survey (AS2COSPEC), and spectroscopic redshifts are measured in 17 of them at z = 2–5. We perform spectral energy distribution analyses and deduce a median total infrared luminosity of L IR = (1.3 ± 0.1) × 1013 L ⊙, infrared-based star formation rate (SFR) of SFRIR = 1390 ± 150 M ⊙ yr−1, stellar mass of M * = (1.4 ± 0.6) × 1011 M ⊙, dust mass of M dust = (3.7 ± 0.5) × 109 M ⊙, and molecular gas mass of M gas = (α CO/0.8)(1.2 ± 0.1) × 1011 M ⊙, suggesting that they are one of the most massive, ISM-enriched, and actively star-forming systems at z = 2–5. In addition, compared to less massive and less active galaxies at similar epochs, SMGs have comparable gas fractions; however, they have a much shorter depletion time, possibly caused by more active dynamical interactions. We determine a median dust emissivity index of β = 2.1 ± 0.1 for our sample, and by combining our results with those from other DSFG samples, we find no correlation of β with redshift or infrared luminosity, indicating similar dust grain compositions across cosmic time for infrared luminous galaxies. We also find that AS2COSPEC SMGs have one of the highest dust-to-stellar mass ratios, with a median of 0.02 ± 0.01, significantly higher than model predictions, possibly due to too-strong active galactic nucleus feedback implemented in the model. Finally, our complete and uniform survey enables us to put constraints on the most massive end of the dust and molecular gas mass functions.

We present the initial results of an ongoing survey with the Karl G. Jansky Very Large Array targeting the CO(J = 1–0) transition in a sample of 30 submillimeter-selected, dusty star-forming galaxies (SFGs) at z = 2–5 with existing mid-J CO detections from the Atacama Large Millimeter/submillimeter Array and NOrthern Extended Millimeter Array, of which 17 have been fully observed. We detect CO(1–0) emission in 11 targets, along with three tentative (∼1.5σ–2σ) detections; three galaxies are undetected. Our results yield total molecular gas masses of 6–23 × 1010 (α CO/1) M ⊙, with gas mass fractions, f gas = M mol/(M *+M mol), of 0.1–0.8 and a median depletion time of (140 ± 70) Myr. We find median CO excitation ratios of r 31 = 0.75 ± 0.39 and r 41 = 0.63 ± 0.44, with significant scatter. We find no significant correlation between the excitation ratio and a number of key parameters such as redshift, CO(1–0) line width, or ΣSFR. We only find a tentative positive correlation between r 41 and the star-forming efficiency, but we are limited by our small sample size. Finally, we compare our results to predictions from the SHARK semi-analytical model, finding a good agreement between the molecular gas masses, depletion times, and gas fractions of our sources and their SHARK counterparts. Our results highlight the heterogeneous nature of the most massive SFGs at high redshift, and the importance of CO(1–0) observations to robustly constrain their total molecular gas content and interstellar medium properties.

The CO(1–0) and [C i](1–0) emission lines are well-established tracers of cold molecular gas mass in local galaxies. At high redshift, where the interstellar medium is likely to be denser, there have been limited direct comparisons of both ground-state transitions. We present a comparison of [C i](1–0) and CO(1–0) emission in 20 unlensed dusty, star-forming galaxies at z ≥ 2–5. The CO(1–0)/[C i](1–0) ratio remains constant up to z = 5, supporting the reliability of [C i](1–0) as a gas–mass tracer. We use the CO(1–0), [C i](1–0), and 3 mm dust continuum measurements to cross–calibrate their respective gas mass conversion factors, finding no dependence of these factors on either redshift or infrared luminosity. Radiative transfer modeling shows that the warmer cosmic microwave background (CMB) at high redshift can significantly affect the [C i] as well as CO emission, which can change the derived molecular gas masses by up to 70% for the coldest kinetic gas temperatures expected. Nevertheless, the magnitude of the CMB effect on the CO/[C i] ratio is within the known scatter of the LCO′−L[CI]′ relation. Precisely determining the CMB effect on individual line intensities would require well-sampled spectral line energy distributions to robustly model the gas excitation conditions. Finally, we note that adopting a variable CO gas–mass conversion factor for different galaxy populations implies [C i](1–0) and dust conversion factors that differ from canonically assumed values. However, the revised conversion factors are consistent with expectations for (super)solar metallicities likely to be found in high-redshift dusty galaxies.

We introduce an ALMA band 3 spectroscopic survey targeting the brightest submillimeter galaxies (SMGs) in the COSMOS field. Here we present the first results based on the 18 primary SMGs that have 870 μm flux densities of S 870 = 12.4–19.3 mJy and are drawn from a parent sample of 260 ALMA-detected SMGs from the AS2COSMOS survey. We detect emission lines in 17 and determine their redshifts to be in the range of z = 2–5 with a median of 3.3 ± 0.3. We confirm that SMGs with brighter S 870 are located at higher redshifts. The data additionally cover five fainter companion SMGs, and we obtain line detection in one. Together with previous studies, our results indicate that for SMGs that satisfy our selection, their brightest companion SMGs are physically associated with their corresponding primary SMGs ≥40% of the time, suggesting that mergers play a role in the triggering of star formation. By modeling the foreground gravitational fields, <10% of the primary SMGs can be strongly lensed with a magnification μ > 2. We determine that about 90% of the primary SMGs have lines that are better described by double Gaussian profiles, and the median separation of the two Gaussian peaks is 430 ± 40 km s−1. This allows estimates of an average baryon mass, which, together with the line dispersion measurements, puts our primary SMGs on the similar mass–σ correlation found on local early-type galaxies. Finally, the number density of our z > 4 primary SMGs is found to be 1−0.6+0.9×10−6 cMpc−3, suggesting that they can be the progenitors of z ∼ 3−4 massive quiescent galaxies.

We report morphological analyses of seven submillimeter galaxies (SMGs) at z ∼ 2 using the James Webb Space Telescope NIRCam images taken as part of the public CEERS and PRIMER surveys. Through two-dimensional surface brightness profile fitting we find evidence of compact reddened stellar structures in all the SMGs, in particular in the F444W filter, suggesting an ubiquitous presence of stellar bulges. The median size of these bulges at F444W with a bootstrapped uncertainty is found to be 0.7 ± 1.0 kpc (0.6–0.7–3.9 kpc for 14th–50th–86th percentiles) and the median Sérsic index is 0.7 ± 0.9 (0.4–0.7–2.8 for 14th–50th–86th percentiles). Structures akin to spiral arms and bars are also identified, and their asymmetric shapes, tidal features, as well as evidence of nearby galaxies at consistent redshifts as those of corresponding SMGs suggest that these SMGs are undergoing dynamical interactions, likely responsible for the triggering of their star-forming activity. Via a curve-of-growth analysis we deduce half-light radii for the NIRCam wave bands, finding that sizes are significantly smaller at longer wavelengths in all cases, in particular that the median size ratio between F444W and F150W is 0.6 ± 0.1. However, we also find that F444W sizes, roughly corresponding to rest-frame H band, are not smaller than those of submillimeter continuum as measured by the Atacama Large Millimeter/submillimeter Array, contradicting certain recent predictions from theoretical models. Our results suggest that while stellar bulges are undergoing an active formation phase in SMGs at z ∼ 2, the total stellar masses of SMGs are still dominated by their disks, not bulges.

The lithium-ion battery is a complicated non-linear system with multi electrochemical processes including mass and charge conservations as well as electrochemical kinetics. The calculation process of the electrochemical model depends on an in-depth understanding of the physicochemical characteristics and parameters, which can be costly and time-consuming. We investigated the electrochemical modeling, reduction, and identification methods of the lithium-ion battery from the electrode-level to the system-level. A reduced 9th order linear model was proposed using electrode-level physicochemical modeling and the cell-level mathematical reduction method. The data-driven predictor-based subspace identification algorithm was presented for the estimation of lithium-ion battery model in the system-level. The effectiveness of the proposed modeling and identification methods was validated in an experimental study based on LiFePO4 cells. The accuracy and dynamic characteristics of the identified model were found to be much more likely related to the operating State of Charge (SOC) range. Experimental results showed that the proposed methods perform well with high precision and good robustness in the SOC range of 90% to 10%, and the tracking error increases significantly within higher (100–90%) or lower (10–0%) SOC ranges. Moreover, to achieve an optimal balance between high-precision and low complexity, statistical analysis revealed that the 6th, 3rd, and 5th order battery model is the optimal choice in the SOC range of 90% to 100%, 90% to 10%, and 10% to 0%, respectively.

ntelligent power consumption system is an important mean to improve the energy efficiency. An embedded terminal was designed in the system, which can achieve intelligent control and management for devices, and reduce power and energy consumption. The terminal in the system was designed and implemented based on ARM platform, using B/S structure to communicate with the remote server through Internet. It has several wired and wireless communication interfaces, which can be connected with various electric equipments. For extensibility, the software of the terminal uses a hierarchical and modular approach which includes communication layer, device layer, interface layer and intelligent power consumption layer. Meanwhile, the communication protocol and the unified interface design in the terminal make sure that the terminal can interact with the remote server reliably and timely. Through experiments in the demonstration operation region, it concludes that the terminals work stable and reliable, and equipment intelligent control and management are fulfilled. The system has many advantages such as modularity and scalability, which can be widely used in many fields like smart grid and smart home, etc.

Because of lacking of effective management and various energy-saving measures, a family smart power management system is introduced. The system includes the servers, LAN and smart power management terminal; the system can control the equipment to achieve the scientific management, and provide users a platform to interact with electrical equipment; the user can use the phone , PAD, PC and other mobile devices log the specified smart power management service website anytime, anywhere to control the electrical household electrical household appliances and query the power consumption, also can control the electrical household electrical household appliances at home through the smart power management terminal. According to the test of the system, the performances verify the system can effectively improve the power consumption rate, and achieve a good energy saving effect.

Technology imagination is a key individual ability that promotes technology progress and innovative economic development. This study aims to achieve three purposes: (1) to develop and validate a technology imagination scale (TIS) through rigorous scale development procedures based on data collected from 553 Taiwanese college students, (2) to compare technology imagination between students from two major higher education institutions in Taiwan, general higher education (GHE) and higher technical and vocational education(HTVE), and (3) to compare students' perceptions across the different dimensions of technology imagination using PR values and radar charts. The results show: (1) The TIS includes 20 items with four factors (connectivity, transcendence, possibility, and technology utilization), demonstrating good reliability and validity. (2) Measurement invariance analysis confirmed the applicability of the TIS to both GHE and HTVE educational tracks. In the dimension of technology utilization, GHE scores significantly higher than HTVE, but there is no significant difference in connectivity, transcendence, and possibility. (3) PR values and radar charts visualize individual students' performance across the four dimensions of technology imagination. This study provides a reliable and valid measurement tool to assess college students' technology imagination, which supports the formulation of educational strategies and the cultivation of innovative talents.

We report physical properties of the brightest (\\(S_870\\, m=12.4\\)-\\(19.2\\,\\)mJy) and not strongly lensed 18 870\\(\\,\\)m selected dusty star-forming galaxies (DSFGs), also known as submillimeter galaxies (SMGs), in the COSMOS field. This sample is part of an ALMA band\\(\\,\\)3 spectroscopic survey (AS2COSPEC), and spectroscopic redshifts are measured in 17 of them at \\(z=2\\)-\\(5\\). We perform spectral energy distribution analyses and deduce a median total infrared luminosity of \\(L_ IR=(1.30.1)10^13\\,L_\\), infrared-based star-formation rate of \\( SFR_ IR=1390150~M_\\, yr^-1\\), stellar mass of \\(M_=(1.40.6)10^11\\,M_\\), dust mass of \\(M_ dust=(3.70.5)10^9\\,M_\\), and molecular gas mass of \\(M_ gas= (_ CO/0.8)(1.20.1)10^11\\,M_\\), suggesting that they are one of the most massive, ISM-enriched, and actively star-forming systems at \\(z=2\\)-\\(5\\). In addition, compared to less massive and less active galaxies at similar epochs, SMGs have comparable gas fractions; however, they have much shorter depletion time, possibly caused by more active dynamical interactions. We determine a median dust emissivity index of \\(=2.10.1\\) for our sample, and by combining our results with those from other DSFG samples, we find no correlation of \\(\\) with redshift or infrared luminosity, indicating similar dust grain compositions across cosmic time for infrared luminous galaxies. We also find that AS2COSPEC SMGs have one of the highest dust-to-stellar mass ratios, with a median of \\(0.020.01\\), significantly higher than model predictions, possibly due to too strong of a AGN feedback implemented in the model. Finally, our complete and uniform survey enables us to put constraints on the most massive end of the dust and molecular gas mass functions.