Yunnan Machinery Research and Design Institute

In this study, representative soil profiles developed on clastic rock parent materials in Yunnan Province were investigated to elucidate the formation mechanisms of soil magnetic properties under weakly magnetic parent material conditions and to evaluate the response of magnetic enhancement to chemical weathering and pedogenic differentiation. A combination of environmental magnetic measurements, bulk geochemical analyses, weathering index calculations, and ternary diagram discrimination was applied to characterize soil magnetic behavior, magnetic grain size distribution, and chemical weathering processes. The results show that the clastic rock parent materials exhibit overall low magnetic intensities, with low-frequency magnetic susceptibility (χlf) ranging from 2.543 × 10−8 m3/kg to 595.652 × 10−8 m3/kg. Under this weakly magnetic background, soils in the study area display pronounced pedogenic magnetic enhancement, with magnetic parameters showing clear and systematic vertical differentiation along soil profiles, indicating that soil magnetic signals are primarily controlled by pedogenesis. The frequency-dependent susceptibility (χfd%) generally falls within the range of 5.403%–17.574%, with a mean value of 12.898%, suggesting a substantial contribution from fine-grained magnetic particles. Magnetic grain size diagnostics further indicate that newly formed superparamagnetic (SP) and stable single-domain (SSD) particles generated during pedogenesis dominate the magnetic enhancement signal. The results of the Chemical Index of Alteration (CIA) indicate that approximately 78% of the profiles reach the strong weathering category (CIA > 85), while only 22% fall into the moderate weathering category (CIA: 65–85). Correlation analyses further reveal that grain-size-sensitive magnetic ratios (e.g., χfd%, χARM/SIRM) exhibit a strong correspondence with chemical weathering intensity indicators. These findings suggest that, under weakly magnetic parent material conditions, pedogenically induced magnetic enhancement can be more readily identified and quantitatively assessed. The integration of environmental magnetism and geochemical approaches, therefore, provides a robust framework for investigating pedogenic differentiation and supports high-resolution paleoenvironmental reconstruction in regions dominated by weakly magnetic parent materials.

In feed drive mechanisms, thermally-induced deformation in the screw-nut pair affects positioning accuracy. Traditional circulating cooling systems regulate screw shaft temperature but fail to address the uneven axial temperature gradient caused by the nut's reciprocating motion, leading to significant positioning errors. To tackle these issues, a novel thermal error control strategy is devised, utilizing a sintered core heat pipe (SCHP) for cooling the moving nut. Specifically, a gas-liquid phase transition model is formulated for the proposed sintered core heat pipe. Furthermore, the heat transfer performance of the sintered core heat pipe is experimentally validated, and a response surface model is constructed to determine its convective heat transfer coefficient. Following this, by integrating into sintered core heat pipe into feed drive mechanisms, the peak temperature of moving nut, thermal equilibrium time, and screw shaft's elongation were measured to be 26.8 °C, 148 min, and 55.1 μm, respectively. The moving nut's peak temperature, thermal equilibrium time, and screw shaft thermal elongation are significantly reduced by 20 %, 28 %, and 23.6 %, respectively. Positioning error reduction in feed drive mechanisms ranges from 74.8 % to 88.7 %. More importantly, the proposed SCHP-cooled strategy is much more effective than traditional circulating cooling system. • Thermal error control strategy is proposed, utilizing sintered core heat pipe. • Sintered core heat pipe is designed towards thermal error control. • Sintered core heat pipe is embedded into cooling jacket. • Fluid-thermal-solid interaction characteristic models are established. • Effect of heat pipe on thermal behavior of feed drive mechanism is studied.

BackgroundMycena is a widespread genus of mushroom capable of decomposing various dead plant substrates. Gastrodia elata is a fully mycoheterotrophic orchid whose seed germination depends on specific Mycena strains. However, only a few Mycena species are capable of inducing germination, necessitating the identification of novel germinating fungal resources.ResultsThe genome of Mycena sp. L02 was sequenced using the Illumina NovaSeq and Oxford Nanopore Technologies (ONT) platforms. The final assembly spanned 160.06 Mb, with 36,246 genes predicted and repetitive sequences accounting for 31.90% (46,496,154 bp) of the genome. A total of 1,339 CAZyme genes were annotated, along with 3,772 genes involved in host–pathogen interactions, 88.33% of which were associated with loss of pathogenicity, reduced virulence, or unaffected pathogenicity. Comparative genomic analysis between germinating and non-germinating Mycena strains revealed that their CAZymes and PHI gene characteristics represent common traits shared across the Mycena genus, with no distinctive features identified. Furthermore, pathways enriched in unique gene families of the germinating fungi—such as glutathione metabolism, sulfur metabolism, phosphatidylinositol signaling system, and inositol phosphate metabolism—may contribute to the germination of G. elata seeds.ConclusionsThe abundance of CAZymes and low-virulence genes in L02 ensures sufficient nutrient acquisition and may facilitate hyphal penetration of the lignin-rich seed coat of G. elata, thereby enabling successful symbiosis. Additionally, KEGG pathways enriched in the unique gene families of the germinating fungi may contribute to the stimulation of seed germination in G. elata. Overall, this study provides a valuable genomic foundation for screening high-performance germinating fungi and further investigating the molecular mechanisms underlying the symbiosis with G. elata.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12864-025-12405-z.

Hirudinaria manillensis is an important blood-sucking medicinal leech widely distributed in Southeast Asia and southern China. It has been shown to treat cardiovascular and cerebrovascular diseases. Molecular identification technology has developed rapidly, and the results are accurate and stable, which can help us to obtain rich biological information of samples for genetic evolution analysis. This study designed 3 pairs of primers for complete cox 1 gene. After sequencing by PCR products and splicing by SeqMan software, the full-length sequence of cox 1 gene was obtained by annotation of open reading frame (ORFs) on MITOS2 platform. The cox 1 gene with a length of 1536nt was obtained, and the species was identified as Hirudinaria manillensis. The Hd value and FST value of cox 1 gene were 0.858 and 0.10938, which were higher than the Hd value of ITS (0.314) and the FST value close to 0. The nucleotide diversity and GST values of the two genes were very low, and the Tajima’s D values of the neutral test were negative, without statistical significance. The genetic distance calculated by the Kimura-2 parameter method was very low. According to the biological information provided by the samples in this study, the population size of Hirudinaria manillensis in southern China was on the rise, but stable genetic diversity was not formed, and there was no obvious population differentiation and geographical isolation. This may be due to the mature artificial breeding technology in recent years, which enabled Hirudinaria manillensis to migrate from the traditional gathering places and breed in a large number in the new environment and migration site. At present, there are many molecular barcoding data of cox 1 gene in the NCBI database, but there is no complete cox 1 gene sequence as a reference, and the related ITS sequence information is more limited, indicating that there is still a lot of space for gene research of Hirudinaria manillensis.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19661-9.

In alignment with national policies and the current demands and trends in the field of education, AI digital empowerment in teaching has emerged as a new highlight in educational reform. Addressing the challenge of leveraging AI to accentuate the student-centered learning approach and to resolve prevalent issues such as imprecision and weak relevance in AI-assisted learning, this paper focuses on student development to explore learning assistance strategies and constructs an AI learning assistant based on RAG technology knowledge base, aiming to provide precise, efficient, and personalized learning support. Firstly, a CPACCP multi-strategy four-stage learning assistance model centered on student development is proposed. This model divides the entire learning process into four assistance nodes: pre-learning, during-learning, learning-stage, and post-learning. It designs six learning assistance strategies including customized plan, personalized learning, active detection, crowdfunding proposal, Cooperative design, and participatory evaluation, forming a learning assistance matrix model in conjunction with learning objectives. Secondly, integrating the CPACCP strategies, this paper elaborates on how to configure roles and external knowledge bases based on RAG technology to construct an AI agent learning assistance tool. Finally, teaching activities are designed using this assistance model, and the constructed AI agent assistant is applied to teaching practice. Analysis shows that this research has promotional value in enhancing teaching and learning effectiveness, fostering students' personalized and autonomous learning interests, and innovation capabilities. It also provides ideas and a research foundation for optimizing educational resource allocation and promoting the innovative development of educational technology.

Soil microbiomes have a crucial role in mulberry development; however, the correlation between the mulberry genotype and rhizosphere microenvironment has not been explored. The rhizosphere microbial community structure and function of rizhosphere bacteria and fungi in five mulberry cultivars and their interaction with soil chemical properties and agronomic traits were analyzed using Illumina-based sequencing. We demonstrated that the composition, structure, and assembly processes of rhizosphere bacteria and fungi exhibited significant differences among mulberry cultivars, and their response to soil chemical traits and leaf yield also varies. The correlations in the bacterial communities were more complex than in the fungal communities among the five cultivars. During the assembly process, bacteria were more stable than fungi. Penicillium and Phytophthora showed a positive correlation with leaf yield and were significantly enriched in the Canghai 12 rhizosphere soil, which exhibited the highest leaf production. Bacillus was a bacterium that showed a significant positive correlation with leaf yield. The saprotrophs exhibited the largest guild in terms of operational taxonomic unit richness. This research indicated that the mulberry genotype is one of the dominant factors in rhizosphere microorganism recruitment and assembly. These findings provide new insights into the complex microbial community soil–plant interaction and probiotic screening.