The integration of machine learning (ML) into materials science has introduced a transformative approach for predicting complex material behavior, particularly in systems where traditional modeling methods face significant limitations. Bulk metallic glasses (BMGs), characterized by their amorphous atomic structure, exhibit unique mechanical properties such as high strength and elastic limit, yet their deformation behavior remains difficult to predict due to the absence of conventional dislocation mechanisms. This study explores the application of data-driven machine learning techniques to model and predict the flow curve and deformation behavior of BMGs under varying conditions. By utilizing experimental datasets that incorporate parameters such as temperature, strain rate, and alloy composition, ML models-including neural networks and support vector machines-are trained to capture nonlinear relationships between input variables and mechanical response. The results demonstrate that ML-based models can accurately reproduce stress-strain behavior and outperform traditional empirical approaches in predictive capability and generalization. Furthermore, the study highlights the advantages of ML in reducing experimental costs and enabling rapid exploration of material design spaces. However, challenges related to data quality, model interpretability, and integration with physics-based frameworks are also discussed. The findings underscore the potential of machine learning as a powerful tool for advancing the understanding and design of amorphous materials, paving the way for future innovations in materials engineering.

A uniquely shaped impact structure,the Hailin impact crater,has been discovered in northeast China.The crater was formed on a granodiorite hillside and is an oval depression with asymmetric rim height and a maximum diameter of 1360 m.The bottom of the crater is filled by Quaternary sediments with large amounts of rock fragments underneath.The discovery of quartz planar deformation features in rock clasts on the crater floor provides diagnostic evidence for the impact origin of the structure.The shape of the crater is largely due to the impact having occurred on a ridge terrain.The impact event probably occurred in the late Cenozoic Era.The Hailin impact crater is the fourth confirmed Chinese impact crater.

The Suizhou meteorite is a heavily shock-metamorphosed L6 chondrite which contains thin shock melt veins. So far, 26 high-pressure phases have been identified from the meteorite. Among the high-pressure phases, ten of them were approved as new minerals which include tuite, xieite, wangdaodeite, chenmingite, hemleyite, poirierite, asimowite, hiroseite, elgoresyite, and ohtaniite, by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association. Other high-pressure phases identified from the meteorite are ahrensite, akimotoite, bridgmanite, lingunite, magnesiowüstite, majorite, majorite–pyropess, maskelynite, riesite, ringwoodite, wadsleyite, and 5 other phases including phase A, vitrified phase B and phase C, phase D (Ca-rich majorite), and partly inverted ringwoodite. The occurrence and abundance of high-pressure phases makes this meteorite the one with the richest variety of high-pressure minerals to date.

Yilan Crater is a newly discovered impact structure in Northeast China. However, the impact process and its subsurface properties have not been properly investigated yet. Here we employed multiple seismic methods to gain insight on its subsurface structures, based on an ultra-dense observation with 220 seismic nodes. We observed a clear site amplification within the circular region of the crater generated by loose sediment and impact-fractured rocks. The resulting bowl-shaped structure beneath the Yilan crater was further revealed by the ambient noise tomography and Horizontal-to-Vertical Spectral Ratio analysis. Multiple solutions for the impact velocity and diameter were found by a parametric investigation, while the impact energy is around 1 E17 Joules, likely representing one of the most significant impact events in the last 80,000 years. These findings offer new insights into the Yilan impact event and its potential effects on the surrounding environment, highlighting the need for further multidisciplinary investigations.

Super-reduced phases (SRPs), such as silicon carbide (SiC) and metal silicides, have increasingly been reported in various geological environments. However, their origin remains controversial. SRP inclusions (e.g., metal silicides and metallic silicon (Si0)) within SiC are commonly believed to indicate a natural origin. Here, we identified an unusual SRP assemblage (SiC, (Fe,Ni)Si2, and Si0) in situ in an H5-type Jingshan ordinary chondrite. Simultaneously, our analysis showed that the SiC abrasives contain (Fe,Ni)Si2 and Si0 inclusions. Other inclusions in the artificial SiC were similar to those in natural SiC (moissanite) reported in reference data, including diverse metal silicides (e.g., FeSi, FeSi2, Fe3Si7, and Fe5Si3), as well as a light rare earth element-enriched SiO phase and Fe-Mn-Cr alloys. These inclusions were produced by the in situ reduction of silica and the interaction between Si-containing coke and hot metals during the synthesis of the SiC abrasives. The results demonstrate that the SRP assemblage in the Jingshan chondrite originates from abrasive contamination and that the SRP inclusions (with a low content of Ca, Al, Ti, and Zr) cannot be used as a conclusive indicator for natural SiC. Additionally, the morphologies, biaxiality, and polytypes (determined by Raman spectroscopy) of SiC abrasives bear resemblance to those reported for natural SiC, and caution must be exercised when identifying the origin of SRP in samples processed by conventional methods using SiC abrasives. At the end of this paper, we propose more direct and reliable methods for distinguishing between natural and synthetic SiC.

An impact structure 1400 m in diameter, formed by a bolide impact, has been discovered on Baijifeng Mountain in Tonghua City in Northeast China’s Jilin province. The impact structure takes the form of a cirque-shaped depression on the top of the mountain and is located in a basement mainly composed of Proterozoic sandstone and Jurassic granite. A large number of rock fragments composed mainly of sandstone, with a small amount of granite, are distributed on the top of Baijifeng Mountain. Planar deformation features (PDFs) have been found in quartz in the rock and mineral clasts collected from the surface inside the depression. The forms of the PDFs indexed in the quartz include among others, {101̄3}, {101̄2}, and {101̄1}. The presence of these PDFs provides diagnostic evidence for shock metamorphism and the impact origin of the structure. The impact event took place after the Jurassic Period and probably much later.

We report the discovery of TiO2-II in the unmelted rock of the shocked Suizhou L6 chondrite. Natural TiO2-II was previously found in ultrahigh-pressure metamorphic and mantle-derived rocks, terrestrial impact structures, and tektite. Our microscopic, Raman spectroscopic, electron microprobe and transmission electron microscopic investigations have revealed: (1) All observed TiO2-II grains are related with ilmenite and pyrophanite; (2) TiO2-II occurs as needle- and leaf-shaped inclusions in ilmenite and patch-, tape-shaped body in pyrophanite; (3) The composition of TiO2-II is identical with that of its precursor rutile; (4) The Raman spectrum of TiO2-II is in good agreement with that of natural and synthesized α-PbO2-type TiO2; (5) TiO2-II occurs mainly in the form of well-ordered nano-domains and small mis-orientation among the domains can be observed. (6) All electron diffraction reflections from TiO2-II can be indexed to α-PbO2 structure in space group Pbcn with lattice parameters of a = 4.481 Å, b = 5.578 Å and c = 4.921 Å; (7) The exsolution inclusions of rutile from host ilmenite are mostly connected with an alternation process along the lamellar twinning plane of ilmenite induced by shock-induced high pressure and high temperature; (8) The P–T regime of 20–25 GPa and 1000 °C estimated for the Suizhou unmelted rock is suitable for phase transition of rutile into TiO2-II phase.

Impact breccia is a unique rock type that formed during the meteorite impact process and it is an ideal sample for the studies on the formation process of impact crater, dating impact craters, and shock effects in minerals and rocks. The Xiuyan impact crater is a simple crater with a diameter of 1800m and large amount of impact breccia in it. Here we mainly document the petrology and shock metamorphism of impact breccias from the Xiuyan impact crater through optical microscope, universal-stage microscope, electron probe microanalysis, X-ray fluorescence, and inductively coupled plasma mass spectrometry and then discuss their formation process and the morphology of impact crater. There are three types of impact breccia in the Xiuyan impact crater, which are the basaltic breccia and the polymict lithic breccia from the upper part of impact breccia lens, and the melt-bearing breccia at the bottom. The clasts in the basaltic breccia and the polymict lithic breccia are weakly shocked and only some quartz grains display planar deformation features which indicate shock pressures less than 20GPa. In contrast, the clasts in the melt-bearing breccia are strongly shocked, in which silicate glass, quartz planar deformation features, coesite, silica glass, diaplectic feldspar glass, reidite are observed, which indicate a shock pressure > 50GPa. This study confirms that the melt-bearing breccia is usually produced at the bottom of simple impact craters and is formed by mixing rock clasts collapsed from the transient crater rim and wall with shock melt at the bottom. The true depth of Xiuyan impact crater is 495m, and the true depth/diameter ration is 0. 275, which is consist with other simple impact craters. The central thickness of impact breccia lens is 188m and the thickness/diameter ration is 0. 104, slightly lower than that of other simple impact craters, which may be due to less rock clasts collapsed into the crater in the modification stage that caused by hilly terrain.

High-temperature phases of solids are often dynamically stable only.First-principles study of point defects in such solids at 0 K is prohibited by their static instability,which results in random structures of the defect-containing supercell so that the total energy of the supercell is randomly affected by structural distortions far away from the defect.Taking cubic perovskite α-CsPbI3 as an example,we first present the problem incurred by the static instability and then propose an approach based on molecular dynamics to carry out ensemble average for tackling the problem.Within affordable simulation time,we obtain converged defect ionization energies,which are unattainable by a standard approach and allow us to evaluate its defect tolerance property.Our work paves the way for studying defects in statically unstable solids.

Coesite embedded in silica glass in suevite from the Xiuyan crater has been studied by scanning and transmission electron microscopy to better understand the mechanisms at formation of coesite. Coesite grains in this study mainly occur as vein‐like aggregates (10–40 μm in width) and irregular aggregates (IAs; <40 μm in size). Both aggregate types are composed of subhedral to anhedral coesite crystals with random orientations. Most of the crystals are 100–1000 nm in size, and some display twinning. The shape, twinning, and random orientation of coesite crystals suggest rapid crystallization in amorphous silica that became supercooled. The center of vein‐like aggregates crystallized from localized silica melt within diaplectic silica glass, whereas the rim of vein‐like aggregates and IAs crystallized from diaplectic silica glass. The size and amount of coesite crystals in the vein‐like aggregate vary greatly from the rim to the center of such veins. Microstructures suggest that the crystals nucleated heterogeneously at the outer rim of the vein and nucleated homogeneously within the vein. IAs do not show any changes in size and amount of coesite crystals from the rim to core of such aggregates. Coesite crystals in IAs primarily nucleate heterogeneously in diaplectic silica glass. It can be concluded that vein‐like coesite aggregates are mainly formed by crystallization from silica melt, and irregular coesite aggregates should be formed by solid‐state transformation of diaplectic silica glass.

The Yilan crater is 1.85 km in diameter and is located in the northeast of China's Heilongjiang Province. The crater is exposed in the Early Jurassic granite of the regional Paleozoic-Mesozoic granite complexes. The southern third of the crater rim is missing, but other rim sections are well preserved, with a maximum elevation above the present crater floor of 150 m. A drillcore from the center of the structure shows that the crater fill consists of 110 m thick lacustrine sediments underlain by a 319 m thick brecciated granite unit mainly composed of unconsolidated granite clasts and fragments. Melt products derived from the target granite, which include melted (and recrystallized) granite clasts, vesicular glass, and teardrop-shaped glass, were found in the brecciated granite unit at 218-237 m depth. Petrographic investigations of unmelted granite clasts in the brecciated granite unit from this depth interval show the presence of multiple sets of planar deformation features (PDFs) in quartz. Orientation measurements for 79 PDF sets in 38 quartz grains with a U-stage indicate the dominance of the omega{101 over bar 3} and pi{101 over bar 2} orientations with a relative frequency of 39% and 18%, respectively. Only 7.6% of the observed PDFs remain unindexed. The observations of PDFs with the appropriate orientations are clear evidence of shock metamorphism and thus of an impact origin of the Yilan structure. Crystallite aggregates of coesite embedded in silica glass were found in the impact-melted granite clasts. The carbon-14 dates of possibly impact-produced charcoal and lacustrine sediments from the crater fill suggest a young age for the impact event of 0.0493 +/- 0.0032 Ma.

氯化钠(NaCl)是一种典型的离子化合物,它的高温高压行为研究对高压物理和化学具有重要的基础和应用意义.为探索NaCl在高温高压下的化学反应性,我们利用金刚石压腔高压装置和双面激光加热技术在85 GPa压力范围内对NaCl样品进行(1800±300)K高温处理,并对淬火后的样品进行拉曼光谱测试.实验结果表明,在压力大于31 GPa时,NaCl分解为斜方结构的NaCl3(Pnma)和四方结构的Na3Cl(P4/mmm).NaCl高温高压下分解产生非1:1化学配比的NaCl3和Na3Cl等非常规化合物,表现出与传统认识截然不同的高温高压性质.这一化学反应表明高温高压下Cl-Cl共价键、Na-Na金属键与常规Na-Cl离子键竞争的结果,可能更有利于NaCl3和Na3Cl组合的稳定出现.金刚石压腔实验中NaCl样品层中存在较大温度梯度,使得样品体系处于一种非平衡状态,这种非平衡态可能是本研究中观察到NaCl发生分解反应的关键.另外,样品体系中用作激光吸收材料的过渡金属氧化物的催化作用可能是促进NaCl分解的另一个因素.高温高压下Pnma-NaCl3化合物的稳定出现,表明地球下地幔深处氯元素也许可以以三氯聚阴离子(Cl3?)形式存在,这种可能的独特赋存方式可以为理解地球演化过程中Cl以及其他卤素元素的分配分异行为提供不同的视角.