Geological Exploration Technology Institute of Jiangsu Province

Context . Jupiter’s atmosphere has strong zonal flows and exhibits marked differential rotation. The dynamic effects of these flows on Jupiter’s gravity field and internal structure have been extensively investigated in order to interpret Juno gravity field data. However, static effects arising from differential rotation are generally ignored in interior modeling. Along with precise measurements of Jupiter’s gravity field, it is of interest to explore the static effects on Jupiter’s shape, gravity field, and interior structure. Aims . We aim to incorporate differential rotation into the fifth-order theory of figures (TOF5) to self-consistently derive planetary shapes and gravitational harmonics. Using Juno gravity field data as constraints, we further investigate the static effects of differential rotation on Jupiter’s shape, gravity field, and interior structure. Methods . We propose a simplified differential rotation model with one free parameter characterizing the intensity of differential rotation. TOF5 is extended to account for differential rotation and is subsequently integrated into Jupiter’s interior models. Results . Our analysis reveals that differential rotation systematically increases Jupiter’s oblateness, with the degree of flattening dependent on the intensity of differential rotation. Absolute values of even gravitational harmonics | J 2 n | increase with the intensity of differential rotation, and higher-order ones exhibit a more pronounced response. Constrained by the Juno gravity data, we find that differential rotation significantly alters Jupiter’s shape and interior structure compared to the results of rigid rotation. The atmospheric metallicity of Jupiter is generally reduced by differential rotation. This implies that a higher 1 bar temperature or a density deficit in part of the molecular envelope is required to interpret the Galileo atmospheric measurement. Furthermore, incorporating differential rotation allows for more heavy elements in Jupiter’s interior, which are mainly concentrated in the metallic hydrogen envelope and the diluted core region. This enrichment is accompanied by a corresponding reduction of heavy elements in the compact core and molecular atmosphere.

Abstract The Quartzite-type crystalline graphite deposit of East China, which is developed in the South Sulu ultrahigh-pressure (UHP) metamorphic belt, represents a medium-sized crystalline graphite deposit. The ore bodies primarily occur within the Banzhuang Formation of the Donghai Group, with their strata-bound occurrence, indicating a sedimentary-metamorphic origin. In this study, petrological, mineralogical and geochemical investigations were conducted on the ore-bearing strata. The quartzite-type graphite ores mainly consist of graphite-bearing diopside quartzite and graphite-bearing sericite-quartz schist. These ores typically occur as lenticular bodies that predominantly preserve early-stage ductile deformation features. The characteristic mineral assemblage (diopside + quartz + calcite + graphite + garnet) suggested amphibolite-facies metamorphic conditions, with the ore type classified as massive crystalline graphite. Major element geochemistry revealed enrichment in SiO 2 and Al 2 O 3 , moderate contents of Fe 2 O 3 and K 2 O, and depletion in CaO and MgO. Protolith analysis indicated the quartzite-type graphite ores were derived from graywacke and claystone deposited in a continental margin to continental island arc setting. Carbon isotope analysis revealed that the organic carbon isotopes (δ 13 C) ranged from −30.8 % to −32.2 %, indicating that the graphite was of biogenic origin. Raman spectroscopy analysis demonstrated well-developed crystallinity of the graphite, suggesting its formation under medium-to high-temperature metamorphic conditions between 430 and 655 °C. Zircon U–Pb geochronology of the graphite ores revealed a dominant age population with a weighted mean age of 733 ± 16 Ma, indicating that magmatic rocks formed during the middle-late Neoproterozoic served as the primary source for the terrigenous clastic components in the Quartzite-type crystalline graphite deposit’s metamorphic sequence. Subsequently, these rocks underwent medium- to high-grade metamorphism accompanied by regional dynamo-thermal metamorphism, which transformed the organic matter into crystalline graphite. It was noted that the ore-bearing strata could be affected by Cretaceous magmatic activity of 110 Ma.

ABSTRACT Based on archival Chandra observations, we present a systematic timing survey of several hundred X-ray sources in M31, M81, and Centaurus A, mostly low-mass X-ray binaries (LXMBs), focusing on searching and characterizing aperiodic and periodic variability within single observation. We identify flares in 24 sources in M31, 5 in M81, and 26 in Cen A; several display recurrent events. Flare durations span from tens of seconds to a few $10^{4}$ s, with peak luminosities of $10^{37}$–$10^{40}\ \mathrm{erg\ s^{-1}}$ and low flare duty cycles of $4.9\times 10^{-6}$–$3.6\times 10^{-2}$. Dipping events are found in 8 sources in M31, 1 in M81, and 5 in Cen A, including two repeaters. On multi-epoch baselines, the standard deviation of the source luminosity correlates linearly with the mean luminosity, with a coefficient of 0.49 (M31), 0.30 (M81), and 0.67 (Cen A), indicating galaxy-to-galaxy diversity. No statistically significant periodic signals are detected in M81 or Cen A, which, along with several periodic signals previously found among the M31 sources, can be understood considering a joint effect of our detection sensitivity and intrinsic distributions of the orbital period and X-ray luminosity of LMXBs. The ensemble of short-duty-cycle flares, a mix of recurrent and isolated dips, and galaxy-dependent rms–flux factor, supports a picture in which stochastic accretion-rate fluctuations modulate luminosity on $\sim$10–$10^{4}$ s. Conducted at known distances and across distinct host environments, this extragalactic survey provides uniform flare/dip samples and rms–flux scalings for bulge-dominated fields, offering empirical constraints for accretion physics and illustrating the promise of timing analyses in external galaxies using the Chandra archive.

Alzheimer's disease (AD) poses a significant challenge in contemporary healthcare, with traditional mouse models often exhibiting prolonged disease progression periods that impede efficient pharmaceutical drug discovery and development. To address this challenge, we developed the FAD3T transgenic mouse model, incorporating three mutations (hAPP, hPSEN1, hMAPT) that closely replicate key genetic factors implicated in AD pathogenesis. The FAD3T model exhibits phenotypic parallels to human AD patients, with early onset of pathogenic markers. Notably, diagnostic blood markers such as p-Tau181, p-Tau217, Aβ42/40, and neurofilament light chain (NfL) are detectable in the plasma of 1-month-old FAD3T mice. Elevated levels of phosphorylated Tau (Thr181) are observed in the brain at 1 month of age. Subsequent observations include Aβ deposition and elevated levels of Phospho-Tau (Thr217, Thr231) at 2 months, followed by elevated levels of Phospho-Tau (Ser396, Ser202, Thr205) at 3 months, with all markers progressively intensifying with age. Importantly, cognitive deficits, including spatial learning and memory impairments, manifest at earlier stages in these mice. Our findings highlight the exceptional fidelity of the FAD3T model in recapitulating the complex etiology of AD. Compared to traditional AD mouse models, FAD3T exhibits accelerated disease onset and progression, providing a rapid platform for expediting drug testing cycles, particularly for therapies targeting disease progression. This innovative mouse model represents a transformative tool for enhancing our understanding of AD pathophysiology and facilitating the expedited development of therapeutic strategies.

Context . Stars and planets form within the same protoplanetary disk, and hence their refractory element abundances are expected to share compositional links. Recent studies have revealed a pronounced non-1:1 relationship between the refractory element abundances of rocky exoplanets and their host stars. This finding is challenged by other works using updated stellar and planetary parameters. Aims . We reanalyze the interior structure of rocky exoplanets by incorporating the updated observational constraints. Through a systematic assessment of model assumptions and statistical methods, we aim to resolve the existing discrepancies and advance our understanding of the compositional link between rocky exoplanets and their host stars. Methods . We modeled the interior structure of 60 close-orbiting rocky exoplanets and derived their possible compositions using Bayesian statistical methods. Their bulk iron-to-silicate ratios were systematically compared with the refractory elemental abundances in their host stars, together with the core mass fraction as a first-order proxy for planetary bulk composition. Results . Despite incorporating the updated measurements, we find that the planet-star compositional link maintains a non-1:1 relationship. It is demonstrated that both interior composition priors and uncertainty propagation methods significantly influence the derived planetary bulk compositions, thereby affecting the inferred star-planet compositional link. Moreover, a positive correlation between planetary iron content and stellar age is also identified, with younger stars hosting planets that are richer in iron. This is because the bulk compositions of rocky exoplanets show a clear correlation with the refractory abundances of their host stars, while the stellar chemical abundances serve as powerful proxies for ages.

Abstract Thin current sheets (TCS) in Earth's magnetotail are fundamental to magnetospheric dynamics. A key question concerning static magnetotail TCSs is the mechanism of radial force balance. Using the unprecedented measurements from the Magnetospheric Multiscale mission, we statistically analyze TCS crossing events from 2017 to 2020 to investigate this issue. Our analysis reveals a strong magnetic tension within TCSs, with the radial thermal pressure gradient accounts for only 10%–30% of the required balance. The off‐diagonal pressure components ( P i , xz and P e , xz ) are crucial for achieving force balance, contributing ∼55% of the required force in the further‐Earth region (−30 R E < X < −20 R E , where R E is Earth's radius), and ∼30% in the near‐Earth region (−20 R E < X < −10 R E ). This work provides the first direct observational evidence demonstrating that particle kinetic effects (ion nongyrotropy and electron pressure anisotropy) play a significant role in the force balance of magnetotail TCSs.