• Book : ()
• Pub. Date : 2025
• Page :
• Keyword :

Red sandstone is widely distributed in southern China. Due to the significant difference in mechanical properties before and after hydration and its poor water stability, red sandstone often triggers landslide accidents. In this paper, red sandstone from an open pit slope in Jiangxi Province was taken as the research object. Two variables, namely the initial saturation degree (25%, 50%, 75%, and 100%) and the number of wetting–drying cycles (0, 10, 20, 30, and 40), were set. With the help of nuclear magnetic resonance, the Brazilian disc test, and fractal theory, the relationships among its meso-structure, macroscopic fracture mechanics characteristics, and deterioration mechanism were analyzed. The research results are as follows: (1) Wetting–drying cycles have a significant impact on the pore structure and fracture mechanics characteristics of red sandstone. Moreover, the higher the initial saturation degree, the more obvious the deterioration effect of the wetting–drying cycles on the rock mass. (2) After further subdividing the pores according to their size for research, it was found that sandstone is mainly composed of mesopores, and the deterioration laws of different types of pores after the wetting–drying cycles are different. The porosities of total pores and macropores increase, while the proportions of mesopores and micropores decrease. The fractal dimensions of macropores and total pores of each group of rock samples are all within the range of 2–3, and the fractal dimension value increases with the increase in the number of wetting–drying cycles, showing significant and regular fractal characteristics. Micropores and some mesopores do not possess fractal characteristics. The fractal dimension of rock samples basically satisfies the rule that the larger the pore diameter, the larger the fractal dimension and the more complex the pore structure. (3) Both the type I and type II fracture toughness of rock samples decrease with the increase in the number of cycles, and the decrease is the most significant when the initial saturation degree is 100%. After 40 cycles, the decreases in type I and type II fracture toughness reach 23.578% and 30.642%, respectively. The fracture toughness is closely related to the pore structure. The porosity and fractal dimension of rock samples and their internal macropores are linearly negatively correlated with the type II fracture toughness. The development of the macropore structure is the key factor affecting its fracture mechanics performance. (4) After the wetting–drying cycles, the internal pores of red sandstone continue to develop. The number of pores increases, the pore diameter enlarges, and the proportion of macropores rises, resulting in internal damage to the rock mass. When bearing loads, the expansion and connection of internal cracks intensify, ultimately leading to the failure of the rock mass. The research results can provide important reference for the stability analysis of sandstone slope engineering.

• Book : 15(2)
• Pub. Date : 2025
• Page : pp.158-158
• Keyword :

This paper presents a study of brane formation in six-dimensional space. There is no a priori assumption of the existence of brane(s). However, an analysis of the generalized Einstein equations shows that there is a set of metrics describing two static branes even in the absence of matter fields. At the same time, no one-brane configurations were found. The trapping of massive particles on branes is a consequence of the metric structure, which prevents these particles from moving between branes. It is shown that communication between charged particles on different branes is provided by photons. Such positron–electron annihilation could be studied experimentally at the LHC collider. The Higgs field is distributed between the branes in such a way that it can serve as a Higgs portal connecting two worlds located on different branes. The values of the 4D physical parameters depend on the extra metric structure near the branes. We also found a non-trivial effect of the decompactification of extra space during the Hubble parameter variation.

• Book : 17(2)
• Pub. Date : 2025
• Page : pp.252-252
• Keyword :

Abstract Near the ends of their lives, supernova remnants (SNRs) enter a “radiative phase,” when efficient cooling of the postshock gas slows expansion. Understanding SNR evolution at this stage is crucial for estimating feedback in galaxies, as SNRs are expected to release energy and momentum into the interstellar medium near the ends of their lives. A standard prediction of SNR evolutionary models is that the onset of the radiative stage precipitates the formation of a dense shell behind the forward shock. In Paper I, we showed that such shell formation yields detectable nonthermal radiation from radio to γ-rays, most notably emission brightening by nearly 2 orders of magnitude. However, there remains no observational evidence for such brightening, suggesting that this standard prediction needs to be investigated. In this paper, we perform magnetohydrodynamic simulations of SNR evolution through the radiative stage, including cosmic rays (CRs) and magnetic fields to assess their dynamical roles. We find that both sources of nonthermal pressure impede shell formation, reducing shell densities by a factor of a few to more than an order of magnitude. We also use a self-consistent model of particle acceleration to estimate the nonthermal emission from these modified SNRs and demonstrate that, for reasonable CR acceleration efficiencies and magnetic field strengths, the nonthermal signatures of shell formation can all but disappear. We therefore conclude that the absence of observational signatures of shell formation represents strong evidence that nonthermal pressures from CRs and magnetic fields play a critical dynamical role in late-stage SNR evolution.

• Book : 980(2)
• Pub. Date : 2025
• Page : pp.167-167
• Keyword :

• Book : 181()
• Pub. Date : 2025
• Page : pp.105619-105619
• Keyword :

ABSTRACTShrew moles (Uropsilus), belonging to subfamily Uropsilinae of family Talpidae, were predominantly found in Myanmar, Vietnam, Bhutan, and Southwestern China. However, the extent distribution range of species within Uropsilus remains unclear. In 2022, we collected 18 specimens of Uropsilus from the western mountains of Henan Province in central China. Based on the mitochondrial (CYT B) and nuclear (RAG1 + RAG2) genes, the phylogenetic relationships, divergence times, and species delimitation of Uropsilus were analyzed. The results showed that the genetic distance of CYT B between new species and other species of Uropsilus ranged from 8.44% to 18.23%; the new species was a distinct valid species and speciated in the early Pleistocene (2.16 Ma, 95% CI = 2.00–2.65) based on phylogenetic analyses. Morphologically, the new species was distinguishable from the other species of Uropsilus by its yellowish–brown dorsum and ash‐black venter, short tail, slender and curved zygomatic arch, upper inward‐curved I1, and lack of a gap between I1 and I2. The combined results of morphological and molecular phylogenetic analysis indicated that the samples from Henan Province represented a new species—Uropsilus funiushanensis sp. nov. The specimens collected from the mountainous area of western Henan Province and Shennongjia in Hubei Province were identified as the same species. We suggested the evolutionary mechanism of the dental formula of U. funiushanensis and U. soricilus groups should be explored in the future.

• Book : 15(2)
• Pub. Date : 2025
• Page :
• Keyword :

Abstract A recent experiment showed that a Cherenkov radiation spectrum from thin radiators with a wavelength-dependent refractive index could transform into quasi-monochromatic spectral lines. Simulations based on the standard Geant4 toolkit could not correctly describe the experimental results because Geant4 uses the traditional Frank-Tamm theory developed for an ideal (infinitely thick) radiator. Because of that, we endeavor to present a new way of utilizing Cherenkov radiation using newly developed Geant4 models and comparing simulation results with the experimental ones. Now, one can analyze quasi-monochromatic Cherenkov spectral lines using Geant4, which is a significant milestone for investigating the possibilities of this technique. Also, this paper should be used as a text to help people understand the Cherenkov process in Geant4 and what one can expect from various models.

• Book : 20(02)
• Pub. Date : 2025
• Page : pp.P02008-P02008
• Keyword :

The density dependence of nuclear symmetry energy Esym(ρ) remains the most uncertain aspect of the equation of state (EOS) of supradense neutron-rich nucleonic matter. Utilizing an isospin-dependent parameterization of the nuclear EOS, we investigate the implications of the observational crustal fraction of the neutron star (NS) moment of inertia ΔI/I for the Esym(ρ). We find that symmetry energy parameters significantly influence the ΔI/I, while the EOS of symmetric nuclear matter has a negligible effect. In particular, an increase in the slope L and skewness Jsym of symmetry energy results in a larger ΔI/I, whereas an increase in the curvature Ksym leads to a reduction in ΔI/I. Moreover, the ΔI/I is shown to have the potential for setting a lower limit of symmetry energy at densities exceeding 3ρ0, particularly when L is constrained to values less than 60 MeV, thereby enhancing our understanding of supradense NS matter.

• Book : 8(1)
• Pub. Date : 2025
• Page : pp.12-12
• Keyword :

Abstract Background Treacher Collins syndrome (TCS, MIM #154500), a severe congenital disorder, predominantly involves dysplasia of craniofacial bones and is characterized by features such as downslanting palpebral fissures, lower eyelid colobomas, microtia, and other craniofacial anomalies. Despite its clinical importance, the underlying pathogenic mutations in TCS remain largely uncharacterized, representing a critical knowledge gap for researchers in the field. Results To address this, we performed mutation screening on a familial TCS case (trio) and 11 sporadic cases from a Chinese population. We identified 11 mutations predominantly localized to the central repeat domain (CRD) and the C-terminal domain (CTD, including the nuclear localization sequence) of TCOF1. The de novo frameshift mutation identified in the trio led to TCOF1 truncation, disrupting the central repeat domain crucial for binding transcriptional factors. Immunoprecipitation assays revealed that this pathogenic mutation attenuates the interaction between TCOF1 and transcription-related proteins, such as Pol II. Furthermore, cellular luciferase assays demonstrated that the mutation compromises the nuclear localization capability of TCOF1. Conclusions Our findings establish TCOF1 as the primary pathogenic gene in this Chinese TCS cohort, with mutations predominantly in the CRD and CTD, thereby expanding the known mutation spectrum of TCS and informing its prevention strategies.

• Book : 20(1)
• Pub. Date : 2025
• Page :
• Keyword :

A novel polarization conversion radome based on dielectric-embedded metamaterial elements is proposed to decrease the size of antenna profiles. This radome is composed of two kinds of interlaced dielectric-embedded metamaterial elements to realize the polarization conversion and beam deflection. The structures and characteristics of two types of dielectric-embedded metamaterial elements have been studied and analyzed. By selecting an appropriate dielectric material and applying periodic boundary conditions to optimize these two kinds of dielectric-embedded metamaterial elements, the radome made up of these metamaterial elements eventually is mounted atop a square horn antenna. Simulation results indicate that the antenna radome enables the horn antenna to achieve polarization conversion and beam deflection at the operating frequency. The maximum beam deflection angle can be 29° within a gain reduction of 1 dB, while the axial ratio remains below 1.5 dB and the reflection coefficient continuously remains below −22 dB. Moreover, the power-handling capacity of each metamaterial element within the radome is above 60 kW.

• Book : 15(2)
• Pub. Date : 2025
• Page :
• Keyword :