Pressure-Induced Phase Transitions in Bismutotantalite (BiTaO): Insights from Single-Crystal Diffraction and Raman Spectroscopy.

In situ high-pressure single-crystal X-ray diffraction and Raman spectroscopy analyses were performed on a natural bismutotantalite with an α-BiTaO structure. The results indicate that α-BiTaO transforms into an orthorhombic phase (HP γ-BiTaO), likely through an intermediate orthorhombic phase (HP β-BiTaO). The transition pressures are 11.

Mapping surface soil organic carbon density of cultivated land using machine learning in Zhengzhou.

Research on soil organic carbon (SOC) is crucial for improving soil carbon sinks and achieving the "double-carbon" goal. This study introduces ten auxiliary variables based on the data from a 2021 land quality survey in Zhengzhou and a multi-objective regional geochemical survey. It uses geostatistical ordinary kriging (OK) interpolation, as well as classical machine learning (ML) models, including random forest (RF) and support vector machine (SVM), to map soil organic carbon density (SOCD) in the topsoil layer (0 - 20 cm) of cultivated land.

Land subsidence prediction in Zhengzhou's main urban area using the GTWR and LSTM models combined with the Attention Mechanism.

In recent years, due to urbanization and human activities, groundwater overexploitation has become increasingly severe, resulting in some degrees of land subsidence and, consequently, causing a series of geological disasters and other environmental issues. Therefore, large-scale and high-precision land subsidence prediction is of great importance for the prevention and control of geological disasters. However, the existing prediction models and methods ignore the effects of the spatiotemporal non-stationary relationships between the influencing factors and the accumulated land subsidence, causing the poor accuracy of the predicted land subsidence results.

Three-Dimensional Elemental Imaging of Nantan Meteorite via Femtosecond Laser Ionization Time-of-Flight Mass Spectrometry.

Femtosecond laser ionization time-of-flight mass spectrometry (fs-LI-TOFMS) is introduced for the three-dimensional elemental analysis of a Nantan meteorite. Spatially resolved multielemental imaging of major and minor compositions in a meteorite are presented with a lateral resolution of 50 μm and a depth resolution of 7 μm. Distinct 3D distributions of siderophile, lithophile, and chalcophile elements are revealed.

Note: Measurement method for sound velocity of melts in large volume press and its application to liquid sodium up to 2.0 GPa.

Based on large volume press and conventional pulse-echo ultrasonic technique, we have overcome the difficulty in determining the length of liquid specimen under high pressure, and the sound velocity in liquid Na has been measured up to 2 GPa. The P-V data deduced by our sound velocity results through equation of state is in an excellent agreement with previous data directly determined by piezometer method. This new experimental technique is convenient and ready for use, being expected to advance investigation on thermodynamic properties of liquid metals and other melts under high pressure.

A simple external resistance heating diamond anvil cell and its application for synchrotron radiation x-ray diffraction.

A simple external heating assemblage allowing diamond anvil cell experiments at pressures up to 34 GPa and temperatures up to 653 K was constructed. This cell can be connected to the synchrotron radiation conveniently. The design and construction of this cell are fully described, as well as its applications for x-ray diffraction.