Chinese Academy of Sciences

Parametric Study of the Torus Instability Threshold

Abstract The torus instability of an arched current channel has been suggested to initiate and drive major solar and stellar eruptions. Its threshold, given by the critical decay index of the equilibrium external poloidal field (the so-called strapping field) at the position of t...

Effect of Nano- and Microparticulate Fermented Fish Protein Hydrolysate Diets on Growth, Digestive Function, Intestinal Development, and Gene Expression in Common Carp (Cyprinus carpio) Larvae

The early larval stage is a major bottleneck in freshwater aquaculture because conventional live feeds are not always available for optimum nutrient availability and digestibility to satisfy the nutritional requirements of developing larvae. This study evaluated the effects of mi...

Navigating the synergy between environmental efficiency and productivity in China's land operation scale expansion

Balancing productivity growth with emissions reduction is a central challenge for sustainable agriculture. Using over 390,000 household-year observations from 1993 to 2020, this study examines how land operation scale affects greenhouse gas emission intensity (GEI) and unit produ...

Response of an Artificial Filled Fracture with Varied Water Contents to Dynamic Stressing

Field observations indicate that gouge-filled faults can be weakened under dynamic stressing and further trigger earthquakes. Previous studies have qualitatively attributed such fault weakening to elevated pore pressure within fault gouges induced by seismic deformation, which re...

Hydrogen‐Dominated Iron Phase Stability and the Structure of the Earth's Inner Core

Abstract The crystal structure of Earth's inner core (IC) remains debated, with the free energy difference between hexagonal close‐packed (hcp) and body‐centered cubic (bcc) iron under IC conditions being very small. We use ab initio and machine learning force field molecular dyn...

Multifunctional Roles of Magnesium Ions in Modulating Bone Regeneration-Related Cells

Magnesium ions (Mg2+) play pivotal roles in bone regeneration by regulating the biological functions of multiple bone repair-related cells. However, the effective concentration ranges and optimal concentration of Mg2+ for different cell types remain incompletely defined, which li...

Climate change and extreme hydroclimatic events primarily regulate sedimentary organic carbon sequestration in an alpine lake on the Tibetan Plateau

Long-term carbon sequestration dynamics of alpine lakes on the Tibetan Plateau under dual pressures from ongoing climate warming and frequent climatic extremes remain poorly understood. Here, we reconstructed century-scale organic carbon burial dynamics and identified organic car...

An exact constant-term reduction and partial p-adic results for Sun's Conjecture 2.2(i)

We prove several rigorous partial results for Zhi-Wei Sun's Conjecture 2.2(i). The numerator is positive, and the exact 2-adic valuation gives the complete 2-adic unit criterion; whenever the quotient is integral, this yields the conjectured parity criterion. An exact all-index f...

Fine-Grained Tree Species Classification in Urban Forests via Phenology–Structure Synergistic Fusion of Multi-Source Remote Sensing Data

Urban forest tree species composition and spatial distribution are essential for refined greenspace management, ecosystem-service assessment, and forest-health monitoring. High-resolution imagery captures crown texture and spatial boundaries, multi-temporal NDVI reflects phenolog...

Disentangling Topographic Constraints and the Climatic and Anthropogenic Pathways Shaping Vegetation Greenness in the Southeastern Qinghai–Xizang Plateau

Vegetation greenness reflects ecosystem responses to climate change and human activities. This study quantified spatiotemporal variation in the normalized difference vegetation index (NDVI) in Nyingchi, a representative alpine-gorge region of the Southeastern Qinghai–Xizang Plate...

Transcriptomic efficiency shapes growth-defense trade-offs in alpine desert plants under climate change

Climate change on the Qinghai-Xizang Plateau, characterized by simultaneous warming and increased precipitation during the growing season, will challenge alpine plants to balance resource acquisition with stress defense. However,the governing physiological and molecular mechanism...

Microbial Colony Image Enhancement Algorithm Based on Composite Adversarial D-DCGAN Neural Network

Microbial testing plays a crucial role in medical and biological research, serving as a significant direction in disease prevention and control studies. Traditional manual testing, which involves identifying colonies on Petri dishes is the best method, but it is not only expensiv...

Structural evolution and thermophysical properties of Tb3ScxAl5-xO12 melts via AIMD and aerodynamic levitation

High-power magneto-optical devices based on terbium garnet crystals require materials with high thermal stability and excellent optical performance. However, their growth is often hindered by instability in high-temperature melts. Here, we combine ab initio molecular dynamics (AI...

Hierarchical multitask learning for upper extremity rehabilitation assessment using wearable sensors

Upper extremity motor impairment following stroke critically limits patients’ functional independence, making continuous and objective rehabilitation assessment vital for guiding recovery. Current clinical evaluations remain largely subjective, confined to clinical settings, and...

Experimental study on rapid formation kinetics of CO2 hydrate based on fly ash medium

Hydrate-based marine carbon sequestration is a promising CCUS strategy because of its high gas storage capacity. However, slow hydrate nucleation and growth, together with fluctuations in formation conditions, hinder efficient carbon capture and long-term stable storage. In this...

Mammalian turnover across the Pliocene-Pleistocene transition: New evidence from the ∼3.0 Ma Dongyancun Fauna, North China

The latest Pliocene (∼3.0–2.5 Ma) large mammals were poorly documented in China. Here we report the Dongyancun Fauna from the Sanmenxia Basin, North China, which provides crucial fossil evidence for this interval. We describe new proboscidean and artiodactyl remains, including St...

Fuglede's conjecture for cyclic groups of square-free order

We prove Fuglede's conjecture for finite cyclic groups of square-free order. Specifically, if N is square-free and A is a nonempty subset of Z_{N} with |A|=m, then A is spectral if and only if it tiles Z_{N}; moreover, these conditions hold precisely when m divides N and A is a c...

Adaptive background suppression-based plume identification, emission estimation, and ground validation of coal mine methane in Changzhi, Shanxi, China

This study developed a coal mine methane remote-sensing monitoring framework centered on adaptive background suppression using high-spatial-resolution multispectral data from Sentinel-2. The framework integrates methane column enhancement retrieval, automated plume detection, and...

Periodic joint co-tiles of independent tiles

For every d ≥ 2, we prove that d-1 independent finite tiles in Z^{d} admit a fully periodic joint co-tile whenever they admit a joint co-tile. Here independence means that the tiles contain the origin and every choice of one nonzero vector from each tile is linearly independent.

Fuglede's conjecture for cyclic groups of square-free order

We prove Fuglede's conjecture for finite cyclic groups of square-free order. Specifically, if N is square-free and A is a nonempty subset of Z_{N} with |A|=m, then A is spectral if and only if it tiles Z_{N}; moreover, these conditions hold precisely when m divides N and A is a c...