The Mongolian Academy of Sciences (Mongolian: Монгол улсын Шинжлэх ухааны Академи, Mongol ulsyn Shinjlekh ukhaany Akademi) is Mongolia's first centre of modern sciences. It came into being in 1921 when the government of newlyindependent Mongolia issued a resolution declaring the establishment of "The Institute of Literature and Scripts", which was later upgraded into "The Institute of Sciences" and "The Institute of Sciences and Higher Education". In 1961, it was finally reorganized as "The Mongolian Academy of Sciences" MAS. At present there are 14 research institutes and two affiliated academies under MAS.
The Upper Paleolithic archaeological record of the Tolbor Valley (northern Mongolia) documents a shift in emphasis from large-blade production to smaller-format bladelet production, characteristic of the Initial Upper Paleolithic (IUP) to Early Upper Paleolithic (EUP) transition in Central and Northeast Asia. This periodization is often associated with, respectively, early dispersal and permanent instalment of Homo sapiens populations in eastern Eurasia. In some regions of West Asia and Europe, an increase in lithic sharp-edge productivity has been described in the EUP, raising the hypothesis that for some groups intensified bladelet production represented a potential solution to constraints on sharp-edge availability. We test this using an allometric approach that controls for blank size, drawing on data excavated from three Upper Paleolithic sites in the Tolbor Valley dated between ca. 45 ka and < 28 ka. A diachronic increase in edge length ( 10 mm) is detected among small flakes (< 5 g) between the IUP and EUP samples, while laminar blanks (blades/bladelets) show no consistent increase. This suggests that the increased emphasis on bladelet production during the EUP at Tolbor was not primarily a response to constraints on sharp-edge availability. Instead, it coincided with more productive small flakes, whether as byproducts of bladelet manufacture or as a parallel/integrated blank production strategy. These results highlight the importance of accounting for blank size when evaluating diachronic trends in sharp-edge productivity.
Lignite is prone to moisture absorption in air due to its abundant oxygen-containing functional groups and complex pore structure. A detailed understanding of its molecular structure is therefore crucial for interpreting dewatering performance and surface wettability. Elemental and industrial analysis, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopy were employed to characterize Mengdong Shengli lignite (SLM). Density functional theory (DFT) and molecular dynamics (MD) simulations were used to validate the lignite model and investigate its surface wettability at the molecular level. The characterization results show that the aromatic and aliphatic carbon contents are 66.84 % and 33.15 %, respectively, with an bridge-to-carbon ratio (XBP) of 0.2162. Oxygen was primarily present in ether bonds, while nitrogen and sulfur occur primarily as pyridinic nitrogen and thiophene structures, respectively. The molecular formula was determined to be C136H125O34N. DFT results indicate an optimal simulated density of 1.21 g/cm3, with non-bonding interactions (EN) being the dominant contributor to macromolecular stability. MD results show good agreement between the simulated and experimental contact-angles, indicating the hydrophilic nature of SLM. The mobility of interfacial water molecules increases continuously with increasing water layer thickness. Analysis of the atomic radial distribution indicates hydrogen bond lengths of approximately 2.05 & Aring; and 1.95 & Aring; between coal and water molecules, suggesting the formation of stable hydrogen-bonded networks at the interface.Theses results contribute to a deeper understanding of coal molecular modeling and wettability behavior.
The first measurement of the magnitude of the CKM quark mixing matrix element |Vcb| using on-shell W-boson decays is presented. The measurement is made with tt events from pp collision data corresponding to an integrated luminosity of 140 fb−1 at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. A value of: |V_cb|=(50_-14^+11)×10^-3 is measured, where the uncertainties have roughly equal contributions from the limited size of the data sample and from systematic effects. This is consistent with existing measurements made at much lower energy scales in B hadron decays. While the sensitivity does not yet rival that of previous determinations, this novel approach probes a very different physical situation, namely the rare hadronic t→ bbc decay at high momentum-transfer, rather than semileptonic B decays at low momentum-transfer.
The top-quark Yukawa coupling is extracted from the distribution of the top-quark pair ( tt ) invariant mass in proton-proton collisions using 140 fb−1 of data at √(s)=13 TeV collected in 2015–2018 by the ATLAS experiment at the Large Hadron Collider. In the region near the production threshold, the tt invariant mass spectrum is sensitive to electroweak virtual corrections, including contributions from Higgs boson exchange, thereby providing sensitivity to the top-quark Yukawa coupling. This is the first measurement in ATLAS that aims to obtain this coupling exploiting this approach. The tt system is reconstructed in the single-lepton final state, requiring exactly one isolated electron or muon and at least four jets with at least two identified as originating from b-quarks. The measured Yukawa coupling is found to be in good agreement with the Standard Model prediction. An upper limit on the top-quark Yukawa coupling strength of Yt < 2.1 relative to the Standard Model prediction is observed at 95
his study presents a probabilistic seismic hazard assessment (PSHA) for Umnugobi (South Gobi) aimag (province), Mongolia, under rock site conditions using a probabilistic model. The analysis was based on integrated data from regional studies of seismic activity, seismotectonics, and active fault investigations. Seismic wave attenuation from earthquake sources was evaluated using a logic-tree approach with four ground-motion prediction equations (GMPEs): Chandra (1979), BSSA-14, CB-14, and CY-14. In total, 28 active faults and five seismotectonic zones were included in the hazard model. The results provide peak ground acceleration (PGA) values corresponding to exceedance probabilities of 63 %, 10 %, and 2 % in 50 years, equivalent to return periods of 50, 475- year, and 2475- year, respectively. According to the current Mongolian seismic building code, the PGA values in Umnugob province are estimated at 134–165 cm/s² for a 475-year return period and 317–396 cm/s² for a 2475-year return period. These findings provide an important scientific basis for engineering seismology, infrastructure planning, seismic risk assessment, and land-use management in the Umnugobi region of Mongolia.
