Mechanism Of Process Research Articles

Molecular dynamics study of the groove-forming mechanism of mechanically scratched grating multilayer aluminum films

For a long time, the forming quality of large area diffraction gratings is restricted by the one-time coating quality and uniformity of large thickness and large area aluminum films. Large thickness coatings, low accuracy of large depth grooves and diamond tool wear problems were the main reasons for the failure of the test to inscribe large area diffraction gratings. Therefore, the use of layered coating process can effectively ensure the uniformity and consistency of large-area and large-thickness grating blanks coated with aluminum film, and improve the high precision of large depth diffraction grating slot type. In order to reveal the mechanism of the groove-forming process of multilayer aluminum films, the microstructure and mechanical properties of different aluminum films were observed. In this article, the removal behavior and mechanism of nanomechanically scratched multilayer aluminum film materials are investigated using a molecular dynamics approach, and the characteristics of multilayer aluminum films scratched into grooves are analyzed in terms of surface morphology, scratching force, structural evolution, dislocation distribution, von Mises stress and shear strain. The results indicate that in the scratching simulation process, multilayer aluminum film has a higher number of removed atoms and a larger atomic displacement compared to single layer aluminum film, which is conducive to precise shape control of the groove. The average tangential force and normal force of multilayer aluminum film show a decreasing trend compared to single layer aluminum film, which helps to scratch grooves and reduce tool wear. The total length of the dislocation lines of the multilayer aluminum film is large, and the distribution area is large, which improves the precision of scratching the grooves. Therefore, an appropriate increase in the number of aluminum film layers has a precise control effect on the groove shape. This study has certain reference significance for analyzing the complex grooving deformation law of grating aluminum film, improving the diffraction efficiency of grating aluminum film, and further improving the manufacturing process of grating aluminum film.

Formation processes and mechanisms of a fault-controlled colluvial landslide in the Qinling-Daba Mountains, China

Faults play a crucial role in shaping the formation and damage patterns of landslides in the mountainous region, particularly in Qinling-Daba (Qinba) area in China. On 6 October 2022, following a 4-day rainfall event totaling 221.5 mm, a landslide occurred in Hanwang Town, Shaanxi Province. The left boundary of the landslide coincided with a fault, which influence the formation and movement development of the landslide. To further understand and quantified the formation process and damage mechanism of the landslide, a comprehensive study was conducted, incorporating field investigations, local rainfall data, and various methods including unmanned aerial vehicles (UAVs), numerical simulations, and laboratory test. The results indicate that fault dictate the formation of the Lijiaping landslide by influencing the mechanical strength of the rock mass and the catchment topography in the landslide area. Due to fault, the rock mass in the landslide area is high fragmentation, with a softening coefficient of about 0.52. Weathering resulted in numerous residual and slope sediments in the landslide area, providing ample material for the landslide. Meanwhile, the fault activity led to a wedge-shaped topography in the landslide area, with an average Terrain Wetness Index (TWI) of 3.43, significantly higher than the Hanwang Township average of 1.47. This creates a hydrogeological structure favorable for landslides. Numerical simulations revealed that the maximum velocity of the landslide reached 5.05 m/s and the maximum displacement was 53.18 m, both occurring in the central part of the landslide. These findings offer crucial scientific insights for understanding and preventing similar geological hazards.

Process mechanism research on direct vortex melting reduction of vanadium–titanium magnetite

Process mechanism research on direct vortex melting reduction of vanadium–titanium magnetite

The variation law and mechanism of titanium alloy MIG welding process under the synergistic effect of coaxial dual channel gas path

The variation law and mechanism of titanium alloy MIG welding process under the synergistic effect of coaxial dual channel gas path

Atomic-level insight into the carburization process of iron-based catalysts: A ReaxFF molecular dynamics study

Transition metal carbide catalysts have garnered widespread attention due to their outstanding catalytic performance. The carbide catalysts, such as FexC and MoxC are typically obtained from their oxide carburization. The reduction and carburization processes are key steps during the activation of oxide precursors, which determine the activity and stability. An understanding of the carburization process mechanism is very important for the optimization of carbide catalysts. Iron-based catalysts are widely used in the large-scale coal-to-liquid industry because of their low price and high activity. In this paper, the carburization process of iron oxide nanoparticles was simulated by the Reactive force field (ReaxFF) molecular dynamics method. The results illustrate that the competition between CO dissociation and reduction of oxides occurs at the 100 ps time scale, which can be tuned by particle size and oxygen vacancy. We have explained the counter-intuitive finding that small oxide particles are more difficult to achieve fully carburization than larger ones; this is because rapid carbon accumulation on the surface blocks the oxygen diffusion channels from bulk to surface. The atomic distribution heat map was carried out to demonstrate the carbon and oxygen penetration processes. Meanwhile, the volumetric strain analysis reveals the driving force comes from the strong tendency to form Fe-C bonds. The dependence on surface orientation was further systematically investigated. This work provides microscopic insights into the carburization process of iron-based materials and the fundamental knowledge for the optimization of catalyst synthesis procedures.

Integrating ATAC-Seq and RNA-Seq Reveals the Signal Regulation Involved in the Artemia Embryonic Reactivation Process.

Embryonic diapause is a common evolutionary adaptation observed across a wide range of organisms. Artemia is one of the classic animal models for diapause research. The current studies of Artemia diapause mainly focus on the induction and maintenance of the embryonic diapause, with little research on the molecular regulatory mechanism of Artemia embryonic reactivation. The first 5 h after embryonic diapause breaking has been proved to be most important for embryonic reactivation in Artemia. In this work, two high-throughput sequencing methods, ATAC-seq and RNA-seq, were integrated to study the signal regulation process in embryonic reactivation of Artemia at 5 h after diapause breaking. Through the GO and KEGG enrichment analysis of the high-throughput datasets, it was showed that after 5 h of diapause breaking, the metabolism and regulation of Artemia cyst were quite active. Several signal transduction pathways were identified in the embryonic reactivation process, such as G-protein-coupled receptor (GPCR) signaling pathway, cell surface receptor signaling pathway, hormone-mediated signaling pathway, Wnt, Notch, mTOR signaling pathways, etc. It indicates that embryonic reactivation is a complex process regulated by multiple signaling pathways. With the further protein structure analysis and RT-qPCR verification, 11 GPCR genes were identified, in which 5 genes function in the embryonic reactivation stage and the other 6 genes contribute to the diapause stage. The results of this work reveal the signal transduction pathways and GPCRs involved in the embryonic reactivation process of Artemia cysts. These findings offer significant clues for in-depth research on the signal regulatory mechanisms of the embryonic reactivation process and valuable insights into the mechanism of animal embryonic diapause.

Investigation of planar sliding deformation and analysis of the damage mechanism of a rocky landslide in Yaoping triggered by highway excavation in Hubei, China

During projects to build roads in China's mountainous areas, which are often characterized by the poor stability of rocky slopes, cases of deformation damage occur frequently. Because of the wide distribution of rocky landslides in the smooth layer, the unavoidable perturbation caused by engineering construction and the seriousness of landslide disasters, the destruction of this type of landslide and the research into prevention of the mechanism cannot be ignored. On 6 February 2023, a rock slide occurred in Yaoping village, Hubei Province, China. Using field investigations, Google satellite images, unmanned aerial vehicle photography, indoor testing and numerical simulations, we analysed the geological situation, deformation characteristics, damage process and triggering mechanism. The results show that the Yaoping landslide is a typical downward plane-sliding rock slide induced by the excavation of a highway. When strain softening occurs, the shear strength and friction coefficient of the slip zone soil are significantly reduced. Excavation caused the factor of safety of the slope to decrease substantially, with a maximum decrease rate of 60.7%. Excavation is considered to be the extrinsic factor that triggered the occurrence of the Yaoping landslide, while the reduction of landslide resistance caused by strain softening of the soil in the slip zone is the intrinsic direct factor that led to the occurrence of this type of landslide. The Yaoping landslide has obvious traction landslide characteristics. The landslide from deformation to destruction has four stages: creep at the leading edge of the landslide; traction deformation in the middle and back of the landslide; slip belt softening; and integral sliding. The prevention and control of this type of landslide requires a larger scope and depth of investigation, in order to identify in advance the possible soft surface in the rock layer, to speculate on the possible formation of landslide destruction mode, and to determine the support scheme and scope according to the geological conditions of the slopes on both sides of the highway. The slip zone soil of the Yaoping landslide was used to obtain the strength index of slip zone soil, which provides data support for the overall deformation characterization of the landslide. The results can provide a reference for the risk management and prevention of rock slides caused by human engineering activities during the excavation of roads.

Stability analysis of rolling mill system for flexible rolling process based on maximum Lyapunov exponent

Flexible rolling technology is the current development trend of strip production industry. However, due to the simultaneous change of mechanical, process and strip specification parameters in the flexible rolling process, the motion state of the system is difficult to analyze and stability control is hard to achieve. In this paper, the active motion characteristics of rolls in flexible rolling technology are considered, and the dynamic rolling process model is established to reflect the influence mechanism of process and specification parameters on the dynamic rolling force. The dynamic model of a 4-high rolling mill was developed and the structure-process-strip coupling strategy was applied to couple the models. The Runge-Kutta method was applied to solve the dynamic equation to obtain the maximum Lyapunov exponential spectrum for a single parameter variation. It is noteworthy that the two-parameter dynamics method was adopted to solve the dynamics on the two-parameter plane considering the nature of simultaneous variation of the system parameters, which solves the limitations of the traditional analytical method and is suitable for the application of the flexible rolling system. The results suggest that the parameters influence the motion state in the form of coupling, the influence pattern of each parameter on the stability is clarified, the evolution of the stable domain under the effect of parameter coupling is revealed, and the parameter matching strategy is determined. The results will provide a solution for the system parameter setting of flexible rolling technology and a theoretical reference for enhancing the stability of the rolling mill.

The Utilization of Rice Husk as Both the Silicon Source and Mesoporous Template for the Green Preparation of Mesoporous TiO2/SiO2 and Its Excellent Catalytic Performance in Oxidative Desulfurization.

In recent years, TiO2-based catalysts have received extensive attention from researchers for their excellent oxidative desulfurization (ODS) performances. In this paper, a series of mesoporous TiO2/SiO2 catalysts with different TiO2 loadings are prepared, using an incipient wetness impregnation method with agricultural waste rice husk as both the silicon source and mesoporous template and tetrabutyl titanate as the titanium source. The effect of different TiO2 loadings on the ODS performance of the samples is investigated, and the appropriate TiO2 loading is 2.5%. Compared with pure TiO2, the 2.5%TiO2/SiO2 sample exhibits high catalytic activity for oxidative desulfurization. This is, on the one hand, due to the high specific surface area and mesopore volume of the 2.5%TiO2/SiO2 sample. On the other hand, it is due to the uniform dispersion of TiO2 grains with an average diameter of 6.1 nm on the surface of the mesoporous SiO2 carrier, which greatly increases the active sites of the 2.5%TiO2/SiO2 sample, thus improving the catalytic activity of the sample. The recycling performances of the 2.5%TiO2/SiO2 sample are further investigated. The results show that, after fifteen cycles, the 2.5%TiO2/SiO2 sample still maintains high conversions of dibenzothiophene (99.8%) and 4,6-dimethyldibenzothiophene (99.7%) without deactivation. In addition, the 2.5%TiO2/SiO2 sample treated with TBHP aqueous solution is characterized by the technique of UV-Vis, and the Ti-peroxo (Ti-OOtBu) species, the active intermediate for the ODS of bulky organic sulfides, is successfully captured. Finally, a possible reaction mechanism for the ODS process over the 2.5%TiO2/SiO2 sample is proposed.

Mendelian randomization implicates causal association between epigenetic age acceleration and age-related eye diseases or glaucoma endophenotypes

BackgroundAge-related eye diseases (AREDs) have become increasingly prevalent with the aging population, serving as the leading causes of visual impairment worldwide. Epigenetic clocks are generated based on DNA methylation (DNAm) levels and are considered one of the most promising predictors of biological age. This study aimed to investigate the bidirectional causal association between epigenetic clocks and common AREDs or glaucoma endophenotypes.MethodsInstrumental variables for epigenetic clocks, AREDs, and glaucoma endophenotypes were obtained from corresponding genome-wide association study data of European descent. Bidirectional two-sample Mendelian randomization (MR) was employed to explore the causal relationship between epigenetic clocks and AREDs or glaucoma endophenotypes. Multivariable MR (MVMR) was used to determine whether glaucoma endophenotypes mediated the association of epigenetic clocks with glaucoma. Multiple sensitivity analyses were conducted to confirm the robustness of MR estimates.ResultsThe results showed that an increased intrinsic epigenetic age acceleration (HorvathAge) was significantly associated with an increased risk of primary open-angle glaucoma (OR = 1.04, 95% CI 1.02 to 1.06, P = 6.1E−04). The epigenetic age acceleration (EEA) of HannumAge was related to a decreased risk of primary angle-closure glaucoma (OR = 0.92, 95% CI 0.86 to 0.99, P = 0.035). Reverse MR analysis showed that age-related cataract was linked to decreased HannumAge (β = −0.190 year, 95% CI −0.374 to −0.008, P = 0.041). The EEA of HannumAge (β = −0.85 μm, 95% CI −1.57 to −0.14, P = 0.019) and HorvathAge (β = −0.63 μm, 95% CI −1.18 to −0.08, P = 0.024) were associated with decreased central corneal thickness (CCT). PhenoAge was related to an increased retinal nerve fiber layer thickness (β = 0.06 μm, 95% CI 0.01 to 0.11, P = 0.027). MVMR analysis found no mediation effect of CCT in the association of HannumAge and HorvathAge with glaucoma. DNAm-based granulocyte proportions were significantly associated with presbyopia, rhegmatogenous retinal detachment, and intraocular pressure (P < 0.05). DNAm-based plasminogen activator inhibitor-1 levels were significantly related to age-related macular degeneration and intraocular pressure (P < 0.05).ConclusionThe present study revealed a causal association between epigenetic clocks and AREDs. More research is warranted to clarify the potential mechanisms of the biological aging process in AREDs.

Enhanced Electrocatalytic Performance of the FePt/PPy-C Composite toward Methanol Oxidation.

A novel FePt/PPy-C composite nanomaterial has been designed and investigated as a methanol oxidation reaction (MOR) electrocatalyst. The FePt nanoparticles with an average diameter of about 3 nm have been prepared by the co-reduction method and then loaded onto the PPy-C composite support. The electrocatalytic performance is affected by the composition of the FePt nanoparticles. The experimental results indicated that the Fe1.5Pt1/PPy-C catalyst exhibited excellent catalytic activity and stability for MOR, with mass activity and specific activity of 1.76 A mgPt-1 and 2.71 mA cm-2, respectively, which are 5.18 and 4.60 times higher than that of the commercial Pt/C catalyst. Density functional theory (DFT) has been employed to simulate the electrical structures of catalyst supports, and the mechanism of the methanol oxidation process has been further analyzed. The heterojunctions of the PPy-C interface could accelerate the electron migration from the electrocatalytic center to the electrodes. The possibility of methanol oxidation has been improved effectively, which can be confirmed by the d-band center and CO adsorption energy on FePt nanoparticles in the DFT calculation results.

Study on Column Leaching Behavior of Low-Grade High Calcium and Magnesium Copper Ore

This paper studies the process mineralogy, mechanism, and kinetics of column leaching behavior of low-grade high-calcium–magnesium copper ore. The effect of sulfuric acid concentration, leach solution spraying intensity, and material particle size on column leaching kinetics is discussed. The kinetic analysis of column leaching of copper indicates that sulfuric acid concentration has a significant impact. As sulfuric acid concentration increases, the limiting step of reaction shifts from chemical reaction control to a combination of chemical reaction and diffusion mixing control. Spraying intensity also affects copper column leaching; increasing intensity shifts the limiting step from diffusion control to mixing control, thereby mitigating the effects of diffusion control. Regarding other elements, it is found that iron leaching is primarily controlled by chemical reaction, while calcium leaching is mainly controlled by chemical reaction. As sulfuric acid concentration increases from 10 g/L to 20 g/L, the limiting step for calcium leaching shifts from chemical reaction control to chemical reaction and diffusion-mixing control.

Synthesis and characterization of CuCoFe2O4@GA/AC as a bio-based matrix magnetic nano-heterogeneous photocatalyst for ceftriaxone degradation from aqueous media

Emerging contaminants such as ceftriaxone are a significant issue in the environment. They have led to a series of ecological, environmental, and health issues, and it is urgent to find a green and secure method to remove antibiotics from water effectively. In this research, the CuCoFe2O4@Gum Arabic (GA)/Activated Carbon (AC) as an innovative bio-based matrix magnetic nanocatalyst was synthesized for the efficient degradation of ceftriaxone from aqueous media. The structure of CuCoFe2O4@GA/AC was characterized via FESEM, EDS, Mapping, XRD, FTIR, VSM, and DRS analyses. The structural analysis of the catalyst revealed its synthesis at the nanometer scale (40–50 nm), exhibiting high magnetic strength (Ms: 5.38 emu/g) and favorable optical properties with a bandgap of 3.6 eV. Under optimized conditions, including a pH of 5, 60 min of irradiation time, 0.24 g/L photocatalyst dose, and ceftriaxone concentration of 5 mg/L, the removal efficiency from synthetic and real samples was 94.43% and 62.5%, respectively. The photocatalytic degradation process of ceftriaxone followed pseudo-first-order and Langmuir–Hinshelwood kinetic models. Furthermore, analysis of the process mechanism indicated a prominent role of the superoxide radical. The catalyst had a high recovery capability and chemical stability. The photocatalytic degradation of ceftriaxone by CuCoFe2O4@GA/AC showcased remarkable efficiency, indicating its potential utility in the treatment of wastewater contaminated with antibiotics.

Theoretical modeling of process heat transfer mechanism in U-shaped molten salt heat exchanger

U-shaped tube molten salt heat exchanger (MSHE) plays an important role for further improving peak shaving capacity of coal-fired unit (CFU) coupled extraction thermal storage system (ETSS). Nevertheless, existing experimental approach cannot reveal process heat transfer characteristics (HTCs) of MSHE. Meanwhile, investigation exploring factors restricting heat transfer enhancement for MSHE in theory is still vacant. In this paper, a theoretical method for MSHE was developed to determine process mechanism of heat transfer to capture perspective of enhanced heat transfer. Heat transfer performance of U-tube MSHE was theoretically unpacked. Deliberating work was executed with inlet water flow rate of 69–139 kg/s, water temperature of 120–170 °C, salt flow rate of 28–58 kg/s and salt temperature of 350–400 °C. Whereupon, the process mechanism of heat transfer inside MSHE was obtained with redeeming lack of theoretical exploration.Research shows, total HTC respectively increases by 2.57 and 1.88 W/(m2·°C) with 10 °C increasing of molten salt inlet temperature (MSIT) and 14 kg/s ascension in condensate flow rate (CFR). It is signified thermal resistance of countercurrent section of MSHE mainly involving HTCs of MSHE with increment of MSIT and CFR. Such privileged sites are main factor restricting heat transfer enhancement. Moreover, total HTC respectively increases by 2.1 and 21.84 W/(m2·°C) with 10 °C upgrading in condensate inlet temperature (CIT) and 6 kg/s increment in molten salt flow rate (MSFR). Contrary to augmenting MSIT and CFR, HTCs changing of MSHE with CIT alteration and MSFR preferment mainly attributed to downstream section and inlet position of MSHE. Meanwhile, it is discovered significant impact is generated for HTCs of MSHE with specific heat changing in molten salt. Furthermore, it was proven that Bell method is suitable for calculating HTC of molten salt on shell side in U-shaped tube MSHE. The research contents in present work can provide reliable basis for optimal design and application of U-tube MSHE in CFU.

Complex dynamics in nonlinear small time-delayed optoelectronic oscillator and application in fast reservoir computing and pulse generation

We investigated a time-delayed optoelectronic oscillator (OEO) that displays a wide range of complex dynamic behavior under small time delay. The phase-space trajectory distributions in different dynamic regimes were compared which brings a new perspective on the underlying mechanism of the transition process. It was found that bifurcation is always possible no matter how small the time delay is even if the universal adiabatic approximation model is invalid. Hereby we proposed a versatile simple oscillator which has a potential capacity as memory carrier and high-dimensional state spatial mapping ability that brings 1000 times computing-efficiency improvements of reservoir computing over the large time delay one. Furthermore, we demonstrated a new approach for a tunable optoelectronic pulse generator (repetition rate at 0.2 MHz and 0.25 GHz) which depends critically on time-delayed input electrical pulse. The proposed oscillator is also a promising system for the applications of fast chaos-based communication.

Discrimination of dislocation in highly doped n-type 4H–SiC by combining electrochemical reaction and molten alkali etching

This work proposes an effective etching method for highly doped n-type 4H–SiC by combining electrochemical reactions and molten alkali etching. By employing our developed method, threading mixed dislocation (TMDs) and threading screw dislocations (TSDs) can be distinctly visualized as hexagonal etching pits of varying sizes. The slightly smaller threading edge dislocations (TEDs) appear as roughly circular etching pits, while basal plane dislocations (BPDs) are revealed as characteristic seashell-shaped pits. Additionally, we provide a reaction equation that elucidates the mechanism of the electrochemical etching process, thus sparking a new investigation into the discrimination of dislocations under molten alkali conditions. By applying a positive voltage to the wafer, we ensure a continuous supply of holes crucial for the reaction, thereby maintaining both the etching rate and the selectivity towards defects. This approach not only enhances the efficiency of the etching process but also provides a more accurate and reliable method for characterizing and understanding the dislocation properties of highly doped n-type 4H–SiC wafers.

Deterministic modelling for driving factors of mineralization in Shanggong gold deposit (China)

1. Three-dimensional (3D) deterministic modeling is crucial for analyzing the controlling factors of mineralization. The Shanggong gold deposit, situated in the southern margin of North China Craton, represents a magmatic hydrothermal deposit. To construct the 3D deterministic model, boreholes, cross-sections, and geochemistry assays are integrated based on the geological characteristics of the Shanggong gold deposit. This paper summarizes its contents as follows: 1) GoCAD software can be utilized to build a 3D geology model encompassing faults and ore bodies; 2) Geostatistics and discrete smooth interpolation (DSI) can be employed to create a 3D attribute model involving grade and Au/Pb ratio. The findings reveal that: 1) High-value zones are associated with NE and NNE trending cross faults; 2) Deterministic modeling, such as grade model and Au/Pb ratio model, effectively elucidates the metallogenic process mechanism.

How Can Scientific Crowdsourcing Realize Value Co-Creation? A Knowledge Flow-Based Perspective

Presently, the practice of scientific crowdsourcing still suffers from user loss, platform operational inefficiency, and many other dilemmas, mainly because the process mechanism of realizing value co-creation through interaction between users and platforms has not yet been elaborated. To fill this gap, this study takes Kaggle as the research object and explores the realization process and internal mechanism of scientific crowdsourcing value co-creation from the perspective of knowledge flow. The results show that the operation process of Kaggle-based scientific crowdsourcing can be decomposed into five progressive evolutionary stages, including knowledge sharing, knowledge innovation, knowledge dissemination, knowledge application, and knowledge advantage formation. The knowledge flow activates a series of value co-creation activities of scientific crowdsourcing, forming a dynamic evolution and continuous optimization of the value co-creation process that includes the value proposition, value communication, value consensus, and all-win value. Institutional logic plays a key role as a catalyst in the value co-creation of scientific crowdsourcing, effectively facilitating the realization of value co-creation by controlling and guiding the flow of knowledge. The study unlocks the “gray box” from knowledge flow to value co-creation, providing new theoretical support and guidance for further enhancing the value co-creation capacity and accelerating the practice of scientific crowdsourcing.

MS2/GmAMS1 encodes a bHLH transcription factor important for tapetum degeneration in soybean.

GmAMS1 is the only functional AMS and works with GmTDF1-1 and GmMS3 to orchestrate the tapetum degeneration in soybean. Heterosis could significantly increase the production of major crops as well as soybean [Glycine max (L.) Merr.]. Stable male-sterile/female-fertile mutants including ms2 are useful resources to apply in soybean hybrid production. Here, we identified the detailed mutated sites of two classic mutants ms2 (Eldorado) and ms2 (Ames) in MS2/GmAMS1 via the high-throughput sequencing method. Subsequently, we verified that GmAMS1, a bHLH transcription factor, is the only functional AMS member in soybean through the complementary experiment in Arabidopsis; and elucidated the dysfunction of its homolog GmAMS2 is caused by the premature stop codon in the gene's coding sequence. Further qRT-PCR analysis and protein-protein interaction assays indicated GmAMS1 is required for expressing downstream members in the putative DYT1-TDF1-AMS-MYB80/MYB103/MS188-MS1 cascade module, and might regulate the upstream members in a feedback mechanism. GmAMS1 could interact with GmTDF1-1 and GmMS3 via different region, which contributes to dissect the mechanism in the tapetum degeneration process. Additionally, as a core member in the conserved cascade module controlling the tapetum development and degeneration, AMS is conservatively present in all land plant lineages, implying that AMS-mediated signaling pathway has been established before land plants diverged, which provides further insight into the tapetal evolution.

Study on thermal runaway propagation characteristics of the lithium-ion battery module by two-phase flow of nitrogen and water mist in longitudinal ventilation environment

To prevent and control the thermal runaway (TR) and its propagation of lithium-ion batteries (LIBs) is a key problem for its sustainable development and wide application. However, there is still a gap in the research on the characteristics of two-phase flow of nitrogen(N2) and water mist (NWM) controlling TR and its propagation in different longitudinal ventilation environments. In this study, the influence of wind velocity on 0.5 MPa NWM to control TR and its propagation characteristic parameters of LIB module was studied experimentally. The results show that with the increase of wind velocities, the opening time of the safety valve and TR trigger temperature of the LIB module gradually increased. At the same wind velocity, TR trigger temperature of cell 1 to cell 5 was successively reduced after 0.5 MPa NWM was applied. The cooling and asphyxiation effect of 0.5 MPa NWM is the best in natural ventilation environment, but the suppression effect of 0.5 MPa NWM on TR propagation of the LIB module is weakened under the influence of forced ventilation. However, different wind velocities have little effect on TR trigger temperature of the blocked LIB module. At the same time, a quasi-steady state thermal equilibrium of the NWM in a ventilation environment was established for the LIB module, and the influence of the coupling effect of different longitudinal ventilation environments and 0.5 MPa NWM on TR propagation characteristic parameters of the LIB module and the heat transfer mechanism in the thermal runaway propagation process were compared under the two conditions of within or without battery case. It is found that the convection effect of the wind plays a leading role in the heat dissipation of the blocked LIB module when the wind velocity is less than 4.5 m/s. The heat conduction of the battery case plays a leading role when the wind velocity is greater than 4.5 m/s. Moreover, in any ventilation environments, TR propagation time of the blocked LIB module is smaller than that of the unblocked LIB module. Under the same wind velocity, TR trigger temperature of the blocked LIB module and the maximum temperature of each cell are higher than that without battery case. This work provides a new perspective for controlling TR propagation of the LIBs. At the same time, it can provide theoretical guidance for ensuring process safety and firefighters to fight LIB fire accidents.