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(1) Background: Functional magnetic resonance imaging (fMRI) utilizing multi-echo gradient echo-planar imaging (ME-GE-EPI) has demonstrated higher sensitivity and stability compared to utilizing single-echo gradient echo-planar imaging (SE-GE-EPI). The direct derivation of T2* maps from fitting multi-echo data enables accurate recording of dynamic functional changes in the brain, exhibiting higher sensitivity than echo combination maps. However, the widely employed voxel-wise log-linear fitting is susceptible to inevitable noise accumulation during image acquisition. (2) Methods: This work introduced a synthetic data-driven deep learning (SD-DL) method to obtain T2* maps for multi-echo (ME) fMRI analysis. (3) Results: The experimental results showed the efficient enhancement of the temporal signal-to-noise ratio (tSNR), improved task-based blood oxygen level-dependent (BOLD) percentage signal change, and enhanced performance in multi-echo independent component analysis (MEICA) using the proposed method. (4) Conclusion: T2* maps derived from ME-fMRI data using the proposed SD-DL method exhibit enhanced BOLD sensitivity in comparison to T2* maps derived from the LLF method. [ABSTRACT FROM AUTHOR]

Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics. The widely adopted strategies to enhance charge transport, such as restraining intermolecular vibration, are mostly limited to organic molecules, which are nearly inoperative in 2D inorganic molecular crystals currently. In this contribution, charge transport in 2D inorganic molecular crystals is improved by integrating charge‐delocalized Se8 rings as building blocks, where the delocalized electrons on Se8 rings lift the intermolecular orbitals overlap, offering efficient charge transfer channels. Besides, α‐Se flakes composed of charge‐delocalized Se8 rings possess small exciton binding energy. Benefitting from these, α‐Se flake exhibits excellent photodetection performance with an ultrafast response rate (~5 μs) and a high detectivity of 1.08 × 1011 Jones. These findings contribute to a deeper understanding of the charge transport of 2D inorganic molecular crystals composed of electron‐delocalized inorganic molecules and pave the way for their potential application in optoelectronics. [ABSTRACT FROM AUTHOR]

Galaxy interactions and mergers can enhance or reduce star formation, but a complete understanding of the involved processes is still lacking. The effect of dwarf galaxy mergers is even less clear than their massive counterpart. We present a study on a dwarf merger remnant in the Virgo cluster, VCC322, which might form a triple system with VCC334 and VCC319. We identify a prominent long and straight tail-like substructure that has a size comparable to its host galaxy VCC322. By comparing the color–color (g − r versus r − H) distribution with simple stellar population models, we infer that the metallicity and stellar age of this tail are Z ⋆ ∼ 0.02 Z ⊙ and t ⋆ ∼ 10 Gyr, respectively. In VCC319, we find a sign of isophotal twisting. This suggests that VCC319 may be subject to tidal interaction. An analysis of the Sloan Digital Sky Survey optical spectra of VCC322 indicates mass- and light-weighted ages of about 109.8 yr and 107.5 yr, respectively, indicating an ongoing star formation activity. However, the star formation in VCC322 seems suppressed when compared to other star-forming dwarfs of comparable stellar masses. Our finding of shock excitation of optical emission lines indicates that interaction-induced shock may contribute to the heating of cold gas and suppression of star formation. [ABSTRACT FROM AUTHOR]

The effective governance of Hg2+ in environmental wastewater is of profound significance to deal with the global pollution issues. However, the present methodologies usually only focused on a single function of either detection or removal, which encounters severe secondary pollution and cumbersome operation cost, while the integration of Hg2+ detection, removal, and recovery in one process is barely realized. In this study, an All‐In‐One photoelectrochemical system is built combining the detection, removal, and recovery of Hg2+ pollutant in a single process, by ingeniously developing a fundamental principle, namely alloying‐induced plasmonic quenching mechanism in Schottky heterostructures. Briefly, the high‐efficiency removal and recovery of Hg2+ in wastewater is realized via the favorable alloying of Hg in Ag nanoparticles that well‐dispersed on the free‐standing WO3 nanoplate networks. The formation of Ag–Hg alloy future leads to a remarkable plasmonic quenching effect of the Ag nanoparticles, which is used to modulate the photoelectrochemical singles to realize the high‐precision detection. Through this ingenious design, an ultralow Hg2+ detection limit of 0.296 nm is achieved with a broad detection range up to 12.5 µm, and meanwhile realize a removal/recovery rate of 100% in single Hg2+ solution and 97 ± 2% in industrial wastewater with multiple contamination ions. The detection and removal/recovery performance parameters reported in the study are much better as compared to the recently reported single function detection or removal/recovery systems. This work opens a fresh avenue in tackling the problem of heavy metal pollution using plasmonic Schottky heterostructure based All‐In‐One systems. [ABSTRACT FROM AUTHOR]

Zn metal anode suffers from dendrite growth and side reactions during cycling, significantly deteriorating the lifespan of aqueous Zn metal batteries. Herein, we introduced an ultrathin and ultra‐flat Sb2O3 molecular crystal layer to stabilize Zn anode. The in situ optical and atomic force microscopes observations show that such a 10 nm Sb2O3 thin layer could ensure uniform under‐layer Zn deposition with suppressed tip growth effect, while the traditional WO3 layer undergoes an uncontrolled up‐layer Zn deposition. The superior regulation capability is attributed to the good electronic‐blocking ability and low Zn affinity of the molecular crystal layer, free of dangling bonds. Electrochemical tests exhibit Sb2O3 layer can significantly improve the cycle life of Zn anode from 72 h to 2800 h, in contrast to the 900 h of much thicker WO3 even in 100 nm. This research opens up the application of inorganic molecular crystals as the interfacial layer of Zn anode. [ABSTRACT FROM AUTHOR]

2D van der Waals (vdW) magnets have opened intriguing prospects for next‐generation spintronic nanodevices. Machine learning techniques and density functional theory calculations enable the discovery of 2D vdW magnets to be accelerated; however, current computational frameworks based on these state‐of‐the‐art approaches cannot offer probability analysis on whether a 2D vdW magnet can be experimentally demonstrated. Herein, a new framework can be established to overcome this challenge. Via the framework, 2D vdW magnets with high probability for experimental demonstration are captured from materials science literature. The key to the successful establishment is the introduction of the theory of mutual information. Historical validation of predictions substantiates the high reliability of the framework. For example, half of the 30 2D vdW magnets discovered in the literature published prior to 2017 have been experimentally demonstrated in the subsequent years. This framework has the potential to become a revolutionary force for progressing experimental discovery of 2D vdW magnets. [ABSTRACT FROM AUTHOR]

The unique intermolecular van der Waals force in emerging two‐dimensional inorganic molecular crystals (2DIMCs) endows them with highly tunable structures and properties upon applying external stimuli. Using high pressure to modulate the intermolecular bonding, here we reveal the highly tunable charge transport behavior in 2DIMCs for the first time, from an insulator to a semiconductor. As pressure increases, 2D α‐Sb2O3 molecular crystal undergoes three isostructural transitions, and the intermolecular bonding enhances gradually, which results in a considerably decreased band gap by 25 % and a greatly enhanced charge transport. Impressively, the in situ resistivity measurement of the α‐Sb2O3 flake shows a sharp drop by 5 orders of magnitude in 0–3.2 GPa. This work sheds new light on the manipulation of charge transport in 2DIMCs and is of great significance for promoting the fundamental understanding and potential applications of 2DIMCs in advanced modern technologies. [ABSTRACT FROM AUTHOR]

The monoclinic GeP with large capacity, low plateau, and high initial coulombic efficiency (ICE) has been proved to be alternative anode for Li‐ion batteries. However, the heavy use of Ge raw material with its high price, hinders its further development. Herein, the Zn atom is proposed for substitution into GeP and replaces part of the Ge owing to its low price, suitable plateau, and similar radius. Interestingly, a novel Ge1−xZnxP solid solution with a wide range tunable region (0.143 < x < 0.6) is achieved, reducing the heavy use of Ge and cutting the GeP price down. More intriguingly, such Ge1−xZnxP possesses a new phase, different from monoclinic GeP, which is first verified to be a cubic system in F‐43m. Compared to semi‐conducting GeP, this cubic Ge1−xZnxP phase possesses metallic conductivity, thus enabling a better rate performance than monoclinic GeP (e.g., 881 vs 283 mAh g−1 at 2000 mA g−1), while keeping the great advantages of large capacity, low plateau, and high ICE of GeP as well. Consequently, the assembled LiCoO2//Ge1−xZnxP full cell exhibits large capacity over 1000 mAh g−1. This unique phase control strategy by atomic substitution can be easily extended to manipulate electrochemical behaviors of other multi‐phase materials toward advanced energy storage. [ABSTRACT FROM AUTHOR]

Metal oxides are archetypal CO2 reduction reaction electrocatalysts, yet inevitable self-reduction will enhance competitive hydrogen evolution and lower the CO2 electroreduction selectivity. Herein, we propose a tangible superlattice model of alternating metal oxides and selenide sublayers in which electrons are rapidly exported through the conductive metal selenide layer to protect the active oxide layer from self-reduction. Taking BiCuSeO superlattices as a proof-of-concept, a comprehensive characterization reveals that the active [Bi2O2]2+ sublayers retain oxidation states rather than their self-reduced Bi metal during CO2 electroreduction because of the rapid electron transfer through the conductive [Cu2Se2]2- sublayer. Theoretical calculations uncover the high activity over [Bi2O2]2+ sublayers due to the overlaps between the Bi p orbitals and O p orbitals in the OCHO* intermediate, thus achieving over 90% formate selectivity in a wide potential range from −0.4 to −1.1 V. This work broadens the studying and improving of the CO2 electroreduction properties of metal oxide systems. It is important yet challenging to improve the interface contact between commonly used carbon conductive layer and metal oxide catalysts. Here the authors propose BiCuSeO with alternant active [Bi2O2]2+ sublayers and conductive [Cu2Se2]2- sublayer within its superlattice as efficient catalyst for CO2 electroreduction to formate. [ABSTRACT FROM AUTHOR]

Searching for room temperature magnetic two-dimensional (2D) materials is a charming goal, but the number of satisfied materials is tiny. Strain can introduce considerable deformation into the lattice structure of 2D materials, and thus significantly modulate their intrinsic properties. In this work, we demonstrated a remarkable strain-modulated magnetic properties in the chemical vapor deposited Cr2Te3 nanoflakes grown on mica substrate. We found the Curie temperature of Cr2Te3 nanoflakes can be positively and negatively modulated under tensile and compressive strain respectively, with a maximum varied value of ∼ 40 and −90 K, dependent on the thickness of samples. Besides, the coercive field of Cr2Te3 nanoflakes also showed a significant decrease under the applied strain, suggesting the decrease of exchange interaction or the change of the magnetization direction. This work suggests a promise to employ interfacial strain to accelerate the practical application of room temperature 2D magnetics. [ABSTRACT FROM AUTHOR]

Activating basal plane inert sites will endow MoTe2 with prominent hydrogen evolution reaction (HER) catalytic capability and arouse a new family of HER catalysts. Herein, we fabricated single MoTe2 sheet electrocatalytic microdevice for in situ revealing the activated basal plane sites by vacancies introducing. Through the extraction of electrical parameters of single MoTe2 sheet, the in-plane and interlayer conductivities were optimized effectively by Te vacancies due to the defect levels. More deeply, Te vacancies can induce the delocalization of electrons around Mo atoms and shift the d-band center, as a consequence, facilitate the adsorption of H from the catalyst surface for HER catalysis. Benefiting by the coordinated regulation of band structure and local charge density, the overpotential at −10 mA·cm−2 was reduced to 0.32 V after Te vacancies compared to 0.41 V for the basal plane sites of same MoTe2 nanosheet. Meanwhile, the insights gained from single nanosheet electrocatalytic microdevice can be applied to the improved HER of the commercial MoTe2 power. That the in situ testing of the atomic structure-electrical behavior-electrochemical properties of a single nanosheet before/after vacancies introducing provides reliable insight to structure-activity relationships. [ABSTRACT FROM AUTHOR]

Using the atomic carbon [C  i ] (⁠|$^{3} \rm P_{1} \rightarrow {\rm ^3 P}_{0}$|⁠) and [C  i ] (⁠|$^{3} \rm P_{2} \rightarrow {\rm ^3 P}_{1}$|⁠) emission {hereafter [C  i ] (1 − 0) and [C  i ] (2 − 1), respectively} maps observed with the Herschel   Space   Observatory , and CO (1 − 0), H  i , infrared and submm maps from literatures, we estimate the [C  i ]-to-H2 and CO-to-H2 conversion factors of α[C  i ](1 − 0), α[C  i ](2 − 1), and αCO at a linear resolution |$\sim 1\,$| kpc scale for six nearby galaxies of M 51, M 83, NGC 3627, NGC 4736, NGC 5055, and NGC 6946. This is perhaps the first effort, to our knowledge, in calibrating both [C  i ]-to-H2 conversion factors across the spiral disks at spatially resolved |$\sim 1\,$| kpc scale though such studies have been discussed globally in galaxies near and far. In order to derive the conversion factors and achieve these calibrations, we adopt three different dust-to-gas ratio (DGR) assumptions that scale approximately with metallicity taken from precursory results. We find that for all DGR assumptions, the α[C  i ](1 − 0), α[C  i ](2 − 1), and αCO are mostly flat with galactocentric radii, whereas both α[C  i ](2 − 1) and αCO show decrease in the inner regions of galaxies. And the central αCO and α[C  i ](2 − 1) values are on average ∼2.2 and 1.8 times lower than its galaxy averages. The obtained carbon abundances from different DGR assumptions show flat profiles with galactocentric radii, and the average carbon abundance of the galaxies is comparable to the usually adopted value of 3 × 10−5. We find that both metallicity and infrared luminosity correlate moderately with the αCO, whereas only weakly with either the α[C  i ](1 − 0) or carbon abundance, and not at all with the α[C  i ](2 − 1). [ABSTRACT FROM AUTHOR]

In this paper we present our studies on the stellar populations and star formation histories (SFHs) for the Reines et al. sample of 136 dwarf galaxies that host active galactic nuclei (AGNs), selected from the Sloan Digital Sky Survey Data Release 8. We derive stellar populations and reconstruct SFHs for these AGN-host dwarfs using the stellar population synthesis code STARLIGHT. Our results suggest that these AGN-host dwarfs have assembled their stellar masses within a narrow period of time with the stellar mass-weighted ages in the range of 109–1010 yr, but show a wide diversity of SFHs with the luminosity-weighted stellar ages in the range of 107–1010 yr. The old population (t > 109 yr) contributes most to the galaxy light for the majority of the sample; the young population (t < 108 yr) also appears in significant but widely varying fractions, while the intermediate-age population (108 < t < 109 yr) in general contributes less to the optical continuum at 4020 Å. We also find that these dwarfs follow a similar mass–metallicity relation to normal star-forming galaxies, indicating that AGNs have little effect on the chemical evolution of the host galaxy. We further investigate the relation between the derived SFHs and morphology of the host galaxy, and find no correlation. Comparing the SFHs with the luminosity of the [O iii ] λ5007 line (), we find a mild correlation exists when erg s−1, indicating a physical connection between star formation and AGN activities in these dwarf galaxies. [ABSTRACT FROM AUTHOR]

A clear link between a dwarf–dwarf merger event and enhanced star formation (SF) in the recent past was recently identified in the gas-dominated merger remnant VCC 848, offering by far the clearest view of a gas-rich late-stage dwarf–dwarf merger. We present a joint analysis of JVLA H i emission line mapping, optical imaging, and numerical simulations of VCC 848 in order to examine the effect of the merger on the stellar and gaseous distributions. VCC 848 has less than 30% of its H i gas concentrated within the central high-surface-brightness star-forming region, while the remaining H i is entrained in outlying tidal features. Particularly, a well-defined tidal arm reaches N(H i) comparable to the galaxy center but lacks SF. The molecular gas mass inferred from the current SF rate (SFR) dominates over the atomic gas mass in the central ∼1.5 kpc. VCC 848 is consistent with being a main-sequence star-forming galaxy for its current stellar mass and SFR. The H ii region luminosity distribution largely agrees with that of normal dwarf irregulars with similar luminosities, except that the brightest H ii region is extraordinarily luminous. Our N-body/hydrodynamical simulations imply that VCC 848 is a merger between a gas-dominated primary progenitor and a gas-bearing star-dominated secondary. The progenitors had their first passage on a near-radial noncoplanar orbit more than 1 Gyr ago. The merger did not build up a core as compact as typical compact dwarfs with a centralized starburst, which may be partly ascribed to the star-dominated nature of the secondary and, in a general sense, a negative stellar feedback following intense starbursts triggered at early stages of the merger. [ABSTRACT FROM AUTHOR]

We present an Atacama Large Millimeter/submillimeter Array observation of the Submillimeter galaxy ID 141 at z = 4.24 in the [N ii ] 205 μm line (hereafter [N ii ]) and the underlying continuum at (rest-frame) 197.6 μm. Benefiting from lensing magnification by a galaxy pair at z = 0.595, ID 141 is one of the brightest SMGs. At the angular resolutions of –1.″5 (1″ ∼6.9 kpc), our observation clearly separates and moderately resolves the two lensed images in both continuum and line emission at a signal-to-noise ratio >5. Our continuum-based lensing model implies an averaged amplification factor of ∼5.8 and reveals that the delensed continuum image has a Sérsic index and Sérsic radius of ∼0.″18 (∼1.24 kpc). Furthermore, the reconstructed [N ii ] velocity field in the source plane is dominated by a rotation component with a maximum velocity of ∼300 km s−1 at large radii, indicating a dark matter halo mass of ∼10. This, together with the reconstructed velocity dispersion field being smooth and modest in value (<100 km s−1) over much of the outer parts of the galaxy, favors the interpretation of ID 141 being a disk galaxy dynamically supported by rotation. The observed [N ii ] /CO (7−6) and [N ii ] /[C ii ] 158 μm line-luminosity ratios, which are consistent with the corresponding line ratio versus far-infrared color correlation from local luminous infrared galaxies, imply a delensed star formation rate of (1.8 yr−1 and provide an independent estimate of the size of the star-forming region kpc in radius. [ABSTRACT FROM AUTHOR]

To study the high-transition dense-gas tracers and their relationships to the star formation of the inner ∼2 kpc circumnuclear region of NGC 253, we present HCN J = 4−3 and HCO+ J = 4−3 maps obtained with the James Clerk Maxwell Telescope. Using the spatially resolved data, we compute the concentration indices r 90/ r 50 for the different tracers. HCN and HCO+ 4–3 emission features tend to be centrally concentrated, which is in contrast to the shallower distribution of CO 1–0 and the stellar component. The dense-gas fraction (f dense, traced by the velocity-integrated-intensity ratios of HCN/CO and HCO+/CO) and the ratio R 31 (CO 3–2/1–0) decline towards larger galactocentric distances, but increase with higher star formation rate surface density. The radial variation and the large scatter of f dense and R 31 imply distinct physical conditions in different regions of the galactic disc. The relationships of f dense versus Σstellar, and SFEdense versus Σstellar are explored. SFEdense increases with higher Σstellar in this galaxy, which is inconsistent with previous work that used HCN 1–0 data. This implies that existing stellar components might have different effects on the high-J HCN and HCO+ than their low-J emission. We also find that SFEdense seems to be decreasing with higher f dense which is consistent with previous works, and it suggests that the ability of the dense gas to form stars diminishes when the average density of the gas increases. This is expected in a scenario where only the regions with high-density contrast collapse and form stars. [ABSTRACT FROM AUTHOR]

As emerging organic contaminants, siloxanes have severe impacts on the environment and human health. Simple linear siloxanes and derivates, trimethylsilanol (TMS), dimethylsilanediol (DMSD), monomethylsilanetriol (MMST), and dimethylsulfone (DMSO2), are four persistent and common problematic compounds (PCs) from the hydroxylation and sulfuration of polydimethylsiloxanes. Herein, through a two-step computational process, namely Grand Canonical Monte Carlo (GCMC) simulations and machine learning (ML), we systematically screened 50 959 hypothetical pure-silica zeolites and identified 230 preeminent zeolites with excellent adsorption performances with all these four linear siloxanes and derivates. This work vividly demonstrates that the collocation of data-driven science and computational chemistry can greatly accelerate materials discovery and help solve the most challenging separation problems in environmental science. [ABSTRACT FROM AUTHOR]

We selected an active galactic nuclei (AGNs) sample (0 < |$z$| ≤ 0.35) from Sloan Digital Sky Survey Data Release 7, and measured the broad- (⁠|$\rm H\alpha ^{b}/H\beta ^{b}$|⁠) and narrow-line Balmer decrements (⁠|$\rm H\alpha ^{n}/H\beta ^{n}$|⁠) of 554 selected AGNs. We found that the distributions of Balmer decrements can be fitted by a Gaussian function and give the best estimates of |$\rm H\alpha ^{b}/H\beta ^{b}= 3.16$| with a standard deviation 0.07 dex, and |$\rm H\alpha ^{n}/H\beta ^{n}= 4.37$| with a standard deviation 0.10 dex. We inspected the distributions of |$\rm H\alpha ^{b}/H\beta ^{b}$| and |$\rm H\alpha ^{n}/H\beta ^{n}$| in the Baldwin−Phillips−Terlevich (BPT) diagram and found that only narrow-line Balmer decrements depend on the physical conditions of the narrow-line region (NLR). We tested the relationship between |$\rm H\alpha ^{b}/H\beta ^{b}$| and |$\rm H\alpha ^{n}/H\beta ^{n}$|⁠, and found that |$\rm H\alpha ^{b}/H\beta ^{b}$| does not correlate with |$\rm H\alpha ^{n}/H\beta ^{n}$|⁠. We investigated the relationship between Balmer decrements and Seyfert sub-type, and found that only broad-line Balmer decrements correlate with Seyfert sub-type, We also examined the dependency of Balmer decrements on AGN properties, and found that Balmer decrements have no correlation with optical luminosity, but show some dependence on accretion rate. These results indicate that the NLR is subject to more reddening by dust than the broad-line region. [ABSTRACT FROM AUTHOR]