Chemical Trends Research Articles

An Adenosine Analogue Library Reveals Insights into Active Sites of Protein Arginine Methyltransferases and Enables the Discovery of a Selective PRMT4 Inhibitor.

Protein arginine methyltransferases (PRMTs) represent promising drug targets. However, the lack of isoform-selective chemical probes poses a significant hurdle in deciphering their biological roles. To address this issue, we devised a library of 100 diverse adenosine analogues, enabling a detailed exploration of the active site of PRMTs. Despite their close homology, our analysis unveiled specific chemical trends unique to the individual members. Notably, compound YD1130 demonstrated over 1000-fold selectivity for PRMT4 (IC50 < 0.5 nM) over a panel of 38 methyltransferases, including the other PRMTs. Its prodrug YD1342 exhibited potent inhibition on cellular substrate methylation, breast cancer cell colony formation, and tumor growth in the animal model, surpassing or matching known PRMT4-specific inhibitors. In summary, our focused library not only illuminates the intricate active sites of PRMTs to facilitate the discovery of highly potent and isoform-selective probes but also offers a versatile blueprint for identifying chemical probes for other methyltransferases.

High-throughput magnetic co-doping and design of exchange interactions in topological insulators

Using high-throughput automation of impurity embedding simulations, we create a database of 3d and 4d transition metal defects embedded into the prototypical topological insulators (TIs) Bi2Te3 and Bi2Se3. We simulate both single impurities as well as impurity dimers at different impurity-impurity distances inside the topological insulator matrix. We extract changes to magnetic moments, analyze the polarizability of nonmagnetic impurity atoms via nearby magnetic impurity atoms and calculate the exchange coupling constants for a Heisenberg Hamiltonian. We uncover chemical trends in the exchange coupling constants and discuss the impurities' abilities with respect to magnetic order in the fields of quantum anomalous Hall insulators and topological quantum computing. In particular, we confirm that co-doping of different magnetic dopants is a viable strategy to engineer the magnetic ground state in magnetic TIs. Published by the American Physical Society 2024

New insights into the metallogenic genesis of the Xiadian Au deposit, Jiaodong Peninsula, Eastern China: Constraints from integrated rutile in-situ geochemical analysis and machine learning discrimination

The genesis of the Mesozoic Au deposit within the Jiaodong Peninsula is debated, with vague connections to magmatism, deep-source metamorphic devolatilization, or the involvement of mantle materials over the long term. This study presents an integrated investigation involving textures, in-situ geochemical analysis, and machine learning discrimination of the rutile of the Xiadian Au deposit at the northwest Jiaodong Peninsula, aiming to provide metallogenic insights. Rutile is distinguished into three types: Type 1 rutile formed in the pre-ore stage is fine-grained and replaces and coexists with relict titanite, with euhedral crystal and being homogeneous and dark BSE response. Type 2 and type 3 rutile exhibit subhedral and anhedral crystals and are associated with quartz-sericite-pyrite alteration. The former has low W contents and is dark BSE response, while the latter is brighter in BSE and exhibits pronounced fragmentation and erosion. Chemical trends indicate the elemental substitution mechanism within rutiles from early to later stages: (Nb, Ta)5+ + (V, Fe, Al, Cr)3+ ↔ 2Ti4+ to 2(V, Fe, Al, Cr)3+ + W6+ ↔ 3Ti4+. Elevated concentrations of trivalent iron ions due to elevated oxygen fugacity of the ore-forming fluids are more likely to have contributed to this change, rather than the increment of W content. This may induce the destabilization of gold-sulfur complexes and contribute to gold mineralization. Machine learning models, including Extreme Randomized Tree (ET), Support Vector Machine, and Naive Bayes classifiers, were trained using a collected dataset containing 6598 rutile geochemistry data. These models consistently classify Xiadian rutile as the hydrothermal origin and having affinity to orogenic Au deposit. The SHapley Additive exPlanation (SHAP) framework was used to explain the discrimination criteria for the best-performing ET models. It revealed that elements such as Y, Ta, Mo, Sn, W, and Nb significantly contribute to classifying Xiadian rutile as affiliated with orogenic Au deposit. Further mass balance calculations with titanite, the predominant precursor Ti-bearing mineral of rutile, suggest that the W content in rutile is controlled by ore-forming fluids, likely having a deep source. In contrast, elements like Y, Mo, Cr, Nb, and Ta are influenced by leaching or re-equilibration with host rocks. Collectively, deep geodynamic processes likely provide major Au mineralization-related materials and fluids, while elemental leaching or re-equilibration with shallow crust rocks near fluid pathways influences the geochemical characteristics of the Xiadian gold system.

Towards characterising rocky worlds: Trends in chemical make-ups of M dwarfs versus GK dwarfs

Elemental abundances of Sun-like stars have been shown to be crucial for understanding the detailed properties of planets surrounding them. However, accurately measuring elemental abundances of M stars, the most abundant class of stars in the solar neighbourhood, is challenging due to their faintness and pervasive molecular features in optical photospheric spectra. As a result, elemental abundances of Sun-like stars have been proposed to constrain those of M stars, particularly by scaling X/H given measured Fe/H This work aims to test the robustness of this convenient practice based on two selected sets of M- and GK-dwarf stellar abundances and a set of rigorous statistical methods. We compiled the elemental abundances of a sample of up to 43 M dwarfs for ten major rock-forming elements (Fe, C, O, Mg, Si, Al, Ca, Na, Ni, and Ti) from high-resolution near-infrared stellar surveys including APOGEE, CARMENES, and Subaru. We carried out bootstrap-based linear regressions on the selected sample of M dwarfs to constrain the statistical trends of X/H versus Fe/H and then compare them with those of GK dwarfs (sampled from the GALAH database). We then applied a two-sample, multivariate Mahalanobis Distance test to assess the significance of the differences in the X/H Fe/H trends for individual elemental pairs between M and GK dwarfs. We find that the null hypothesis -- that is, no significant difference in the chemical trends of X/H versus Fe/H between M and GK dwarfs -- is strongly rejected for all elements except for Si, for which the rejection is marginal ($p$-value close to 0.05), and Na and Ni, for which the results are inconclusive. This finding suggests that assuming no difference may result in biased results, and thus inaccurate constraints on characterising rocky planets around M dwarfs by scaling the (unmeasured) chemical abundances of planet-hosting M dwarfs from the chemical trends of X/H Fe/H determined by GK dwarfs. It is therefore crucial for both the stellar and exoplanet communities to be aware of these observed differences. To better understand these differences, we advocate for dedicated modelling techniques for M-dwarf atmospheres and an increasing set of benchmark, homogeneous abundance analyses. Intermediately, our statistically constrained trends of X/H Fe/H for M dwarfs provide a new constraint on estimating M-dwarf elemental abundances given measured Fe/H and further on characterising the detailed properties of M-dwarf-hosted rocky worlds.

Chemical Trends of the Bulk and Surface Termination-Dependent Electronic Structure of Metal-Intercalated Transition Metal Dichalcogenides.

The addition of metal intercalants into the van der Waals gaps of transition metal dichalcogenides has shown great promise as a method for controlling their functional properties. For example, chiral helimagnetic states, current-induced magnetization switching, and a giant valley-Zeeman effect have all been demonstrated, generating significant renewed interest in this materials family. Here, we present a combined photoemission and density-functional theory study of three such compounds: , , and , to investigate chemical trends of the intercalant species on their bulk and surface electronic structure. Our resonant photoemission measurements indicate increased hybridization with the itinerant NbS2-derived conduction states with increasing atomic number of the intercalant, leading to pronounced mixing of the nominally localized intercalant states at the Fermi level. Using spatially and angle-resolved photoemission spectroscopy, we show how this impacts surface-termination-dependent charge transfers and leads to the formation of new dispersive states of mixed intercalant-Nb character at the Fermi level for the intercalant-terminated surfaces. This provides an explanation for the origin of anomalous states previously reported in this family of compounds and paves the way for tuning the nature of the magnetic interactions in these systems via control of the hybridization of the magnetic ions with the itinerant states.

Using Soil Magnetic Susceptibility Proxies to Estimate Overburden Thickness Overlying Ore of Lateritic Soils in Sulawesi Island Indonesia

Sulawesi Island is one of the largest Ni ore producers in Indonesia. It is also expected to be a significant potential source of some critical metals (e.g., Co, Sc, rare-earth elements, and platinum-group elements). However, few studies show the post-mining impact on some heavy metal elements concentrated in this area. Therefore, improving the efficiency and effectiveness of soil organization and its effect on soil reclamation after mining is helpful. This study aimed to determine the accuracy in estimating the thickness of the overburden covering the nickel ore body profile from lateritic nickel post-mining areas by magnetic susceptibility measurements to discrepancy the overall laterite horizon, whereas χLF and χFD are used to distinguish the overburden zona and limonite and saprolite zone. The lateritic profile studied consists of soil formation of Fe-rich material in the Morowali, and Pomalaa block. We also evaluated the chemical element content of the soil and understood the relationship between the magnetic and geochemical properties of the soil. This study reveals the superparamagnetic (SP)-enriched soils indicated with the increase of the FD% values into the upward horizon, where the maximum values of FD are generally found at ranges 1 to 4m, indicating the overburden layers. Meanwhile, in the depth of 4m to 6m, the values of FD vary only slightly in the lower part initiated by the limonite layers, and then &gt; 6m decreases sharply to the bottom, indicating the saprolite layers. The chemical element mobility trends indicate that Fe, Co, Cr, Mn, and Ti increase toward the layers, which is the same pattern as in FD. Due to this, parameters magnetics may also be a new geophysical approach for estimating the distribution of economically valued minerals on lateritic soils. The strong correlation of Co with Fe, Mn, and Cr in all layers indicates the influence of weathering o n these ultramafic rocks. This suggests an increasing trend toward prolonged pedogenesis.

Analysis of Chemical Changes during Maturation of Amomum tsao-ko Based on GC-MS, FT-NIR, and FT-MIR.

Amomum tsao-ko Crevost et Lemaire (A. tsao-ko) is widely grown for its high nutritional and economic value. However, the lack of a scientific harvesting and quality control system has resulted in an uneven product quality. The present study was based on A. tsao-ko from four maturity stages from the same growing area, and its chemical trends and quality were evaluated using a combination of agronomic trait analysis, spectroscopy, chromatography, chemometrics, and network pharmacology. The results showed that A. tsao-ko was phenotypically dominant in October. Spectroscopy showed that the absorbance intensity at different maturity stages showed a trend of October > September > August > July. Further chemical differences between A. tsao-ko at different stages of maturity were found by chromatography to originate mainly from alcohol, aromatic, acids, esters, hydrocarbons, ketone, heterocyclic, and aldehydes. The network pharmacology results showed that the active ingredient for the treatment of obesity was present in A. tsao-ko and had high levels in A. tsao-ko in September and October. The results of this study provide a new idea for the comprehensive evaluation of A. tsao-ko and a theoretical basis for the harvesting and resource utilization of A. tsao-ko.

Chemical process fault detection and trend analysis based on KESN

AbstractFault detection has great significance for chemical process safety with the development of science and technology. The conventional echo state network‐based fault detection method does not highlight key fault features, and cannot forecast future fault trend after the occurrence of faults. For the above problems, a chemical process fault detection and trend analysis strategy based on key feature enhanced echo state network (KESN) is proposed. First, dynamic features are extracted by a detecting echo state network. Then, a weighting strategy is designed to enhance key features and increase fault detection rates. After detecting a fault, independent component analysis is utilized to extract independent key features. Future fault trend is forecasted based on the forecasting multi‐KESN. Simulation results on the Tennessee Eastman process demonstrate the effectiveness of the proposed method.

Density functional model of threshold voltage shifts at High-K/Metal gates

A density functional analysis of oxide dipole layers used to set the threshold voltages in high-K/metal CMOS gate stacks is given in terms of the band alignments and chemical trends of these component oxide layers. The oxides SrO, La2O3, HfO2 and Al2O3 are found to have similar band gaps and form a ‘staircase’ of band alignments, allowing them to shift the metal electrode Fermi level in both n-type and p-type directions. This analysis supersedes previous largely empirical models based on metal oxide ion densities or electronegativity scales.

The metal-poor edge of the Milky Way’s “thin disc”

Context. The emergence of the disc in our Galaxy and the relation between thick and thin disc formation and evolution is still a matter of debate. The chemo-dynamical characterization of disc stars is key to resolving this question, particularly at parameter regimes, where both disc components overlap, such as the region around [Fe/H] ∼ −0.7 corresponding to the thin disc’s metal-poor end. Aims. In this paper, we re-assess the recent detection of a metal-poor extension of stars moving with thin-disc-like rotational velocities between −2 &lt; [Fe/H] &lt; −0.7, carried out on the basis of metallicity estimates obtained from photometric data and their rotational velocity distributions. Methods. We explored the chemo-dynamical properties of metal-poor stars from the recent Gaia third data release (DR3), which includes the first catalog of metallicity estimates from the Radial Velocity Spectrometer (RVS) experiment. We complemented them with the two largest high-resolution (λ/dλ &gt; 20 000) spectroscopic surveys available: the GALAH DR3 and the APOGEE DR17. Results. We confirm that there are high-angular-momentum stars moving in thin-disc-like orbits, that is, with a high angular momentum of Lz/Jtot &gt; 0.95, and close to the Galactic plane, |Zmax|&lt; 750 pc, reaching metallicity values down to [Fe/H] ∼ −1.5. We also find tentative evidence for stars moving on such orbits at lower metallicities, down to [Fe/H] ∼ −2.5, albeit in smaller numbers. Based on their chemical trends, thin-disc-like stars with [Fe/H] &lt; −1 would have formed in a medium that is less chemically evolved than the bulk of the thick disc. Stars with chemical abundances typical of the thin disc appear at metallicities between −1 &lt; [Fe/H] &lt; −0.7.

Causal emergent principles and relations for mechanical properties of covalent and ionic crystals

A knowledge and data-synergized intelligent computation architecture for materials was proposed within the data science paradigm. As a vital operation, two digital ensemble descriptors implying chemical composition and structural trend for crystals were created using the features contained in the Periodic Table of elements without a priori assumption, which affords causal emergence and regulation principles for the mechanical response of covalent and ionic solids. In addition to a linear correlation among structural state/mechanical response parameters, causal analytic relations in an exponential form between structural and thermodynamic state/mechanical response parameters and a digital ensemble descriptor were unveiled through least squares regression, in which the coefficients are classified in accordance with symmetry principles on the atom and lattice. Thereafter, the underlying physicochemical mechanisms of chemical pressure and chemical bonding are found responsible for the mechanical responses of bulk modulus and hardness of solids. At last, a physical prediction model was established for crystalline solids and demonstrated the feasibility of the predictive design of novel superhard materials. It is believed that by constructing suitable digital ensemble descriptors, this intelligent computation architecture and consequent physical prediction models on the basis of causal analytic relations are able to generalize by depicting crystalline solids with covalent and ionic bonds in other crystallographic structures.

Chemical Technology and Development Trend of Contaminated Land Remediation

In recent years, the rapid development of industry and agriculture in China has led to the destruction of soil environmental quality caused by pesticides, heavy metals and other pollutants entering the soil, and the decline of crop yield and quality. Therefore, soil pollution remediation is urgent, and it is urgent to explore the remediation technologies of polluted land with good remediation effect, low cost and popularization. This paper summarizes the relevant technologies in the literature, expounds several practical measures of chemical remediation technology of polluted land in detail, and discusses the development trend of contaminated land remediation technology in the future, in order to provide theoretical support for promoting the remediation technology of polluted land in China.

Groundwater Chemical Trends Analyses in the Piedmont Po Plain (NW Italy): Comparison with Groundwater Level Variations (2000–2020)

The concentrations of chemicals in the groundwater chemical values in the Piedmont Po Plain (NW Italy) show significant temporal variability and need to be characterised due to the lack of regional-scale assessments. The aim of this study was to analyse the trends (period 2000–2020) in the main physicochemical parameters and main ions in 227 wells in the shallow aquifer and to identify the potential causes. The identification of change points (points of sudden change) and comparisons with groundwater level variations were also performed. Results highlight general increasing trends for Na, Cl and HCO3, decreasing trends for SO4 and NO3, stationary conditions for pH and heterogeneous behaviours for electrolytic conductivity, Ca and Mg. Change points occurred in at least 50% of the monitoring wells, mainly during the 2008–2011 period. The comparison between groundwater levels and chemistry highlights a direct proportionality. Superimposed processes that induce an absence of proportionality are shown. The comparison of results with those of previous studies conducted under similar conditions revealed similar variations.. In conclusion, the potential responsible factors (e.g., road-salt dissolution and agricultural practices) and the relevant role of groundwater level variation were identified.

Chemical trend of radiative recombination in III-nitrides

Chemical trend of radiative recombination in III-nitrides

Orbital-Selective Mott Transition Effects and Nontrivial Topology of Iron Chalcogenide.

The iron-based superconductor FeSe_{1-x}Te_{x} has recently gained significant attention as a host of two distinct physical phenomena: (i)Majorana zero modes that can serve as potential topologically protected qubits, and (ii)a realization of the orbital-selective Mott transition. In this Letter, we connect these two phenomena and provide new insights into the interplay between strong electronic correlations and nontrivial topology in FeSe_{1-x}Te_{x}. Using linearized quasiparticle self-consistent GW plus dynamical mean-field theory, we show that the topologically protected Dirac surface state has substantial Fe(d_{xy}) character. The proximity to the orbital-selective Mott transition plays a dual role: it facilitates the appearance of the topological surface state by bringing the Dirac cone close to the chemical potential but destroys the Z_{2} topological superconductivity when the system is too close to the orbital-selective Mott phase. We derive a reduced effective Hamiltonian that describes the topological band. Its parameters capture all the chemical trends found in the first principles calculation. Our findings provide a framework for further study of the interplay between strong electronic correlations and nontrivial topology in other iron-based superconductors.

Detailed chemical composition of the globular cluster Sextans A GC-1 on the outskirts of the Local Group

The chemical composition of globular clusters (GCs) across the Local Group provides information on chemical abundance trends. Studying GCs in isolated systems in particular provides us with important initial conditions plausibly unperturbed by mergers and tidal forces from the large Local Group spirals. We present a detailed chemical abundance analysis of Sextans A GC-1. The host galaxy, Sextans A, is a low-surface-brightness dwarf irregular galaxy located on the edge of the Local Group. We derive the dynamical mass of the GC together with the mass-to-light ratio and the abundances of the alpha , Fe-peak, and heavy elements. Abundance ratios were determined from the analysis of an optical integrated-light spectrum of Sextans A GC-1, obtained with UVES on the VLT. We apply non-local thermodynamic equilibrium (NLTE) corrections to Mg, Ca, Ti, Fe, and Ni. The GC appears to be younger and more metal-poor than the majority of the GCs of the Milky Way, with an age of 8.6pm 2.7 Gyr and $ Fe/H dex. The calculated dynamical mass is dyn odot $, which results in an atypically high value of the mass-to-light ratio, 4.35pm 1.40 M$_ odot $/L$_ V odot $. Sextans A GC-1 has varying alpha elements -- the Mg abundance is extremely low, Ca and Ti are solar-scaled or mildly enhanced, and Si is enhanced. The measured values are $ Mg/Fe Ca/Fe Ti/Fe and $ Si/Fe which makes the mean alpha abundance (excluding Mg) to be enhanced $ &lt;Si,Ca,Ti&gt;/Fe NLTE The Fe-peak elements are consistent with scaled-solar or slightly enhanced abundances: $ Cr/Fe Mn/Fe Sc/Fe and $ Ni/Fe The heavy elements measured are Ba, Cu, Zn, and Eu. Ba and Cu have sub-solar abundance ratios ($ Ba/Fe and $ Cu/Fe &lt;-0.343$), while Zn and Eu are consistent with their upper limits being solar-scaled and enhanced, $ Zn/Fe &lt;+0.171$ and $ Eu/Fe The composition of Sextans A GC-1 resembles the overall pattern and behaviour of GCs in the Local Group. The anomalous values are the mass-to-light ratio and the depleted abundance of Mg. There is no definite explanation for such an extreme abundance value. Variations in the initial mass function or the presence of an intermediate-mass black hole might explain the high mass-to-light ratio value.

Revisiting day-of-week ozone patterns in an era of evolving US air quality

Abstract. Past work has shown that traffic patterns in the USA and resulting NOx emissions vary by day of week, with NOx emissions typically being higher on weekdays than weekends. This pattern of emissions leads to different levels of ozone on weekends versus weekdays and can be leveraged to understand how local ozone formation changes in response to NOx emission perturbations in different urban areas. Specifically, areas with lower NOx but higher ozone on the weekends (the weekend effect) can be characterized as NOx-saturated and areas with both lower NOx and ozone on weekends (the weekday effect) can be characterized as NOx-limited. In this analysis, we assess maximum daily 8 h average (MDA8) ozone weekend–weekday differences across 51 USA nonattainment areas using 18 years of observed and modeled data from 2002–2019, using the following two metrics: mean MDA8 ozone and percentage of days with MDA8 ozone &gt; 70 ppb (parts per billion). In addition, we quantify the modeled and observed trends in these weekend–weekday differences across this period of substantial NOx emission reductions in the USA. The model assessment is carried out using U.S. Environmental Protection Agency (EPA)'s Air QUAlity TimE Series Project (EQUATES) Community Multiscale Air Quality (CMAQ) model dataset. We identify three types of MDA8 ozone trends occurring across the USA, namely transitioning chemical regime, disappearing weekday effect, and no trend. The transitioning chemical regime trend occurs in a subset of large urban areas that were NOx-saturated (i.e., volatile organic compound (VOC)-limited) at the beginning of the analysis period but transitioned to mixed chemical regimes or NOx-limited conditions by the end of the analysis period. Nine areas have strong transitioning chemical regime trends using both modeled and observed data and with both metrics indicating strong agreement that they are shifting to more NOx-limited conditions: Milwaukee, Houston, Phoenix, Denver, the Northern Wasatch Front, the Southern Wasatch Front, Las Vegas, Los Angeles – San Bernardino County, Los Angeles – South Coast, and San Diego. The disappearing weekday effect was identified for multiple rural and agricultural areas of California which were NOx-limited for the entire analysis period but appear to become less influenced by local day-of-week emission patterns in more recent years. Finally, we discuss a variety of reasons why there are no trends in certain areas including complex impacts of heterogeneous source mixes and stochastic impacts of meteorology. Overall, this assessment finds that the EQUATES modeling simulations indicate more NOx-saturated conditions than the observations but do a good job of capturing year-to-year changes in weekend–weekday MDA8 ozone patterns.

Comparison of natural corn cob and carbon corn cob in the purification of used cooking oil with shaker operation

The research aims to determine the adsorption ability and modeling of adsorption kinetics to purify used cooking oil using natural and carbonized corn cob adsorbent, which is economical, efficient, and sustainable due to its low price, renewability, and simplicity. Samples of used cooking oil were taken as much as 100 ml with an adsorbent mass of 3 g and particle size of 50 mesh and stirred using a shaker. Based on the results, it was found that the effect of carbonization was able to reduce the turbidity of used cooking oil, whereas for the use of natural corn cob adsorbent, at 20 minutes, turbidity of 59.0 NTU was obtained and 45.2 NTU was obtained after the adsorption process for 5 hours, while for the use of corn cob carbon adsorbent, a turbidity of 62.8 NTU was obtained for the same adsorbent size and 39.8 NTU was obtained after the adsorption process for 5 hours. Chemical interaction trends were also obtained, as shown in the second-order pseudo graph with coefficient of determination (R2) values close to 1 using natural corn cob and corn cob carbon adsorbents, namely 0.9965 and 0.9959.

Controls of lithology and climate over chemical weathering trends: new insights from the precipitation-dominated Dokriani glacier, central Himalaya, India

Abstract The chemical composition of meltwater-draining Himalayan glacierized basins reflects the dominance of carbonic acid in weathering of silicate and carbonate minerals, yet the role of sulfuric acid-mediated reactions in the mineral weathering and ionic release is still unclear. Here, we present a long-term study (1992–2018) of chemical weathering characteristics of a precipitation-dominated glacierized basin (Dokriani glacier) of central Himalaya. By using new and reprocessed datasets of major ions from the glacial/subglacial zones of the glacier, we suggest that two-thirds of the dissolved load of the meltwater derives from sulfuric acid-mediated weathering of minerals and rocks. We observed a clear control of carbonic acid-mediated reactions in the early ablation periods, while sulfuric acid-mediated reactions dominate in peak and late ablation periods. The slopes and intercepts in best-fit regressions of [*Ca2+ + *Mg2+ vs *SO42− and HCO3−] and [HCO3− vs *SO42−] in meltwater were following the stoichiometric parameters of sulfide oxidation coupled to carbonate dissolution reactions. The glaciers of the central and western Himalaya are in good agreement with the present estimates. We contend that the bedrock lithology has limited or second-order effects over the ionic release from Himalayan glaciers and surmise that these patterns are broadly applicable to the other orogenic systems of the world.

Chemodynamical Nature of the Anticenter Stream and Monoceros Ring

In the epoch of deep photometric surveys, a large number of substructures—e.g., overdensities and streams—have been identified. With the help of astrometry and spectroscopy, the community has revealed a complex picture of our Milky Way (MW) after investigating their origins. The off-plane substructures the Anticenter Stream (ACS) and Monoceros Ring (MNC), once considered as dissolving dwarf galaxies, were later found to share similar kinematics and metallicity with the Galactic outer thin disk. In this work, we aim to chemically tag ACS and MNC with high-accuracy abundances from the APOGEE survey. By extrapolating chemical abundance trends in the outer thin-disk region (10 < R GC < 18 kpc, 0 < ∣Z GC∣ < 3 kpc), we found that ACS and MNC stars show consistent chemical abundances as the extrapolating values for 12 elements, including C, N, O, Mg, Al, Si, K, Ca, Cr, Mn, Co, and Ni. The similar chemical patterns indicate that ACS and MNC have a similar star formation history as the MW outer thin disk, while we also excluded their dwarf galaxy association, as they are distinctive in multiple chemical spaces. The ages of ACS and MNC stars are consistent with the time of the first Sagittarius dSph passage, indicating their possible connection.