Evolution Rules Research Articles

Deeply buried clastic rock diagenesis evolution mechanism of Dongdaohaizi sag in the center of Junggar fault basin, Northwest China

Abstract To reveal the diagenetic sequence of reservoir rocks in the central part of the deep depression basin, the Wuerhe Formation in Junggar Basin was taken as an example to conduct the detailed studies on its sedimentary facies, diagenetic sequence, and the micropore structure evolution rules based on the comprehensive data from a super deep exploration well C-6 (approximately 7,000 m in depth). First, an arid environment fan delta sedimentary model of the Wuerhe Formation was established, and its sedimentary evolution law was clarified as a gradual transition from a fan delta front to a fan delta plain during the water-regression process until the lake dried up. Then, the diagenesis types and evolution sequence of the Wuerhe Formation, and the influence degrees of the compaction, cementation, and dissolution on the rock formation process were clarified. Finally, the diagenesis and pore evolution model was established, and the greatest impact factors of the late reservoir densification were clarified. Based on this research, the diagenesis and pore evolution processes of the deep rocks in the studied deep central sag were ultimately revealed to provide useful guidance for the deeply buried oil and gas reservoir exploration.

Research Progress of Bronze Ware Ornamentation in the Shang Dynasty of China

Bronze ware is an important representative of ancient Chinese culture, and the Shang Dynasty is the peak of China’s bronze casting technology. As an important symbol of ancient culture, the bronze ornaments of Shang Dynasty in China. Deeply reflect the religious belief, social structure and cultural value at that time. Through a systematic literature review of the origin, classification and evolution of the bronze ornament, this paper aims to deepen the understanding of the Shang Dynasty bronzes and their cultural connotation. Among the existing studies, the current research on Shang Dynasty bronze ornament mainly focuses on the categorization of ornament, its relationship with culture and the evolution rules. Specifically, the classification of bronze ornament is diverse and represents the different symbolic meanings. Shang Dynasty bronze ornaments are closely related to religious beliefs and social structures, and evolved over time. In general, these studies have enriched the cultural knowledge of Shang Dynasty bronzes, while some rare ornaments have been understudied and the research methods need to be further innovated. The significance of this study is clear: by examining Shang dynasty bronze ornament, it can increase people’s understanding of ancient Chinese religious culture and feudal social structure, and also contribute to the identification and conservation of modern bronzes. Future research can apply modern scientific and technological tools to further reveal the deeper connotations and historical value of Shang culture.

Hygrothermal aging behavior of C/GFRP hybrid rod with bundle‐by‐bundle dispersion

AbstractFiber hybrid with bundle‐by‐bundle dispersion can achieve the high performance of composites, fully understand the hybrothermal resistance of hybrid composites is the key to prove the applications in engineering structures. In the present paper, the hygrothermal resistance performances of new type carbon and glass fiber reinforced epoxy based hybrid rod with bundle‐by‐bundle dispersion produced by pultrusion technology is investigated experimentally. The tests of water absorption and desorption, thermal and mechanical performances are performed to obtain the evolution rules of hygrothermal aging. As a result, the water absorption of hybrid rod confirms to the Fick's diffusion behavior, the serious relaxation of resin matrix and the interfacial debonding of fiber‐resin exposed at high temperature provide more diffusion space for water molecules. Long‐term hydrothermal aging results in the recoverable plasticization of resin matrix and irrecoverable interfacial debonding of fiber‐resin, which brings about the degradation of 6.7%–15.0% for short beam shear strength (SBSS) retention. In addition, the plasticization effect reduces the cross‐linking density of resin matrix, which leads to the degradation of 3.3%–15.6% for glass transition temperature (Tg) retention. The life prediction results show that degradation rate of SBSS is gradually slow down and reached to a stable retention of 85.5%.Highlights Relaxation of resin matrix and interfacial debonding accelerate the diffusion of water molecules. Plasticization and interfacial debonding lead to the degradation of short beam shear strength retention and glass transition temperature. Long‐term life prediction shows that short beam shear strength e retention is 85.5%.

Study on the evolution rules of coal deformation and failure characteristics caused by multiple mining disturbances

During coal mining operations, the coal will be deformed and damaged due to multiple mining disturbances (MMD), often resulting in disasters, like rock burst. To understand the evolution rules of coal deformation under MMD and its final fracture characteristics after impact dynamic load loading, reduce the adverse effects of mining disturbances, and improve disaster prevention and control capabilities, quasi-static uniaxial cyclic loading-unloading (L-U) and dynamic axial compression tests were conducted on large-sized coal-like samples. During the tests, three-dimensional (3D) laser scanning and acoustic emission (AE) monitoring technology were utilized to accurately capture the full-field deformation and AE response data, facilitating a systematic analysis of deformation and fracture characteristics. The results show that: (1) Under the cyclic L-U effect induced by MMD, each loading cycle causes compression deformation with partial recovery during unloading, presenting an overall “wavy” variation trend. (2) The maximum load is the most critical factor affecting the damaged coal deformation, with smaller load resulting in less overall sample deformation. (3) After the impact dynamic loading, the damaged samples suffered large-scale impact splitting failure, with the compressive-shear layer failure mainly occurred inside the holes. (4) Lower loading during cyclic L-U process correlate with reduced damage degree, and smaller debris particles with a higher fractal dimension when impact failure occurs, indicating a more severe impact failure. (5) With multiple cycles of L-U, the cracks inside the sample gradually extend and expand from around the hole to the outside. The greater the load and the number of cycles, the more serious the crack damage will be. (6) In the practical mining process, it is crucial to reinforce roadway interiors while minimizing low-loading cyclic disturbances induced by MMD. The study has obtained the deformation evolution rules and failure characteristics of coal under MMD, providing a theoretical basis for the prevention and control of corresponding engineering disasters.

Crack evolution and fractal characteristics of fractured red sandstone based on acoustic emission parameters

Rock is a widely used engineering material, and accurate understanding of its internal microcrack evolution process during loading can provide a theoretical basis for preventing instability and failure in rock engineering. The rock pressure test system and acoustic emission equipment were used to carry out uniaxial loading and acoustic emission monitoring tests on fractured red sandstone. Based on the RA and AF values of acoustic emission and the fractal theory, the internal crack patterns and evolution rules of red sandstone with different crack angles were explored. The results show that the compressive strength of red sandstone varies with the crack Angle in the shape of “U”, and there is an obvious stress drop after the elastic stage of 30° and 45° crack red sandstone, which has a good correspondence with the acoustic emission ringing count rate. During the loading process, the damage mainly caused by tension cracks first appears inside the rock, and then the tension cracks increase steadily and the shear cracks gradually increase, indicating that the rock enters the stage of fracture instability development. With the development of shear cracks, the peak strength is finally reached and the instability failure occurs. During the loading process of 30° fracture red sandstone, the corresponding stress drop phenomenon of “shear crack group” appears. According to the D/S statistical analysis of different crack samples based on acoustic emission ringing count, the fractal dimension presents a decreasing-rising-decreasing trend with the increase of crack inclination, which corresponds to the change of the complexity of crack development in rock.

Unconventional mechanical responses and mechanisms of Ti-6Al-4V sheet subjected to electrically-assisted cyclic loading-unloading: Thermal and athermal effects

For the sake of unveiling the macro-micro behaviors and underlying control mechanisms of electroplastic effect (EPE) of sheet metals during recent thriving electrically-assisted incremental forming (EAIF) processes, electrically-assisted cyclic loading-unloading tension (EACT) experiments were carried out at a current density of 14～20A/mm2 followed by forced and unforced cooling. The electro-thermo-mechanical responses and the evolution rules of dislocation configurations, fracture modes, phase composition and local orientation distribution were characterized by IR imaging, SEM, quantitative EBSD and TEM tests. Moreover, the thermal and athermal components of the electrically-induced stress drop throughout the EACT processes were decoupled and systematically analyzed via temperature control tests and isothermal correction. The results show that thermal effect of electric current possesses a great proportion of 75 % in the overall stress drop and plays a key role in elastic modulus degradation and ductility enhancement by activating pyramidal {101‾1}⟨12‾10⟩ slip systems, weakening (0001) texture and promoting dynamic recrystallization (DRX) and α→β→α′ phase transformation. While the athermal effect only operates after reaching both threshold current density and plastic strain, it increases monotonically with current density, brings about “hot spots” effect, local charge imbalance and weakened atomic bonding, and further causes intensified local strain gradient, substructure formation and DRX nucleation. The ratio of athermal stress drop first decreases and then increases significantly with loading cycle at the later stage of EACT under the combined effect of local Joule heating effect and flow localization. Additionally, the athermal effect only activates short-range solute diffusion and localized diffusional α→β phase transformation, while the combined thermal and athermal effects promote long-range solute diffusion and an increasing rate in β content of 261.8 %. The present work provides theoretical basis for optimizing the EAIF forming process and realizing extreme manufacture of light-weight thin-walled complex components.

Characterize the influences of hydraulic fracturing on preventing rock burst from the stress and vibration fields

The thick and hard roof (THR) is a significant factor that induces rock burst incidents. Traditional deep-hole blasting methods struggle to effectively relieve pressure for the high-level THR on a large scale. Although the horizontal staged hydraulic fracturing technology can crack high-level rock stratas, its impact on roof fracture still needs to be clarified, and there need to be more effective methods to evaluate its pressure relief effect. This paper conducted a comparative engineering test of local hydraulic fracturing pressure relief and load reduction on the working face to address this gap. The key layer theory and mine earthquake distribution were used to identify potential hazards of rock strata and the fracturing strata. Revealed the spatial and temporal evolution rules of microseisms induced by mining work, the failure mechanism of high-energy mine earthquakes, the evolution characteristics of source mechanical parameters, and the evolution characteristics of the stope stress field. The results indicate that after fracturing microseisms during mining presented exhibit a uniform distribution of high frequency and low energy. The fracture fragmentation of the roof rock was reduced, and the range of mining disturbance was minimized. High-energy mine earthquakes induced by mining are transferred to the goaf. Simultaneously, the corner frequency and stress decrease while the rupture radius and the shear component of the failure mechanism increase. The integrity of the THR is compromised, and fracture propagates and slips along the pre-crack. The roof of the working face experiences localized pressure, with decreased periodicity and intensity, reducing the overall static load level of the coal seam under the fracturing area. The research findings serve as a valuable reference for further investigations into the mechanism and risk assessment of hydraulic fracturing in preventing and controlling rock burst.

Will a plant germplasm accession conserved in a genebank change genetically over time?

The simplified question on the genetic change of a conserved plant germplasm accession over time is raised for a better understanding of the challenging mission of conserving more than 7.4 million germplasm accessions in 2000 genebanks worldwide for generations to come. Its answer will influence how these genebanks operate to ensure the continued survival and availability of the conserved plant genetic resources for future food security. Here, we explore the expected impact of evolutionary forces on plant germplasm in genebanks, search for the theoretical expectations and empirical evidence for such impacts from the literature, and discuss the ramifications of the evidence for long-term plant germplasm management and conservation. It is expected that genetic changes of long-term conserved germplasm under genebank conditions will occur commonly as an evolutionary rule, not as an exception. Incorporating evolutionary biology into the Genebank Standards and operational procedures will benefit the mission of long-term germplasm conservation.

Calculation method and evolution rule of the strain energy density of sandstone under true triaxial compression

Deep rock masses are typically in complex stress states, and research on the evolution of their strain energy density is of highly important for understanding their failure characteristics. In this work, a true triaxial stress‒balanced unloading test is designed to analyze the ud and ue evolution of sandstone under true triaxial compression conditions. The study results indicate that as σ1 increases, the elastic strain decreases in the σ2 and σ3 directions, whereas the residual strain progressively increases, and the magnitude of decrease in elastic strain exceeds the magnitude of increase in residual strain. Throughout the loading process of σ1, ue progressively decreases in the σ2 and σ3 directions, whereas ud gradually increases, and the magnitude of decrease in ue surpasses the magnitude of increase in ud. The ud and ue of sandstone under different stress levels were calculated via true triaxial stress‒balanced unloading tests, and the evolution of ud and ue in the three principal stress directions and the overall strain energy density of sandstone followed a linear energy storage law. On the basis of this law and the true triaxial stress‒balanced unloading test, a new method for calculating the true triaxial ud and ue was proposed. A study on the σ1 unloading stress path revealed that the σ1 unloading stress path significantly affects the storage and dissipation of the strain energy density in the three principal stress directions of sandstone. On the basis of the research results, the criteria for determining rockbursts were discussed.

The tripartite evolutionary game of enterprises' green production strategy with government supervision and people participation

Government supervision and people participation play vital roles in enterprises' green production strategy, but few studies have considered the strategy choices behind government supervision and people's participation. This study contended that whether an enterprise adopts the green production strategy is influenced not only by its responsible attitude facing social responsibility but also by the following two factors, the intensity of government supervision and whether people choose to participate in supervision or not when facing the enterprise adopting the green production strategy or not. We constructed a tripartite evolutionary game model to explore the behavioral evolution rules and evolutionary stability strategies of government supervision, people participation, and enterprises' green production. Then we employed numerical simulation to analyze how various factors influence the strategy selection of the government, people, and enterprises. The results show that if the utility values of government supervision and people participation are greater than 0, the enterprises will adopt the green production strategy. The system stability is affected by a synergistic relationship between participation cost, reputation benefit, and government subsidies, and an incremental relationship between enterprises' green production benefit, government subsidies, people's reported bonus, and enterprises' green production cost. This study provides a new theoretical perspective for research on government supervision, people participation, and enterprises' green production strategy, and the results provide important references for improving the enterprises' green production and urban environmental management.

A new approach on constitutive modeling for quasi-brittle materials under multiaxial loading

Abstract This work introduces a new method for expanding unidimensional models to predict material behavior under multiaxial loading. The concept of six-dimensional mechanical space is adopted, and in each basis direction of the space, there is one fiber-bundle model (FBM), so these six FBMs are independent amongst one another but follow the same damage evolution rule. Under triaxial loading, these FBMs have different stress and strain states, so six corresponding damage variables have different values. The anisotropic damage is thus represented by the six damage variables. When it is under uniaxial loading, the six-dimensional space reduces to one-dimensional space, so the proposed model can be calibrated using uniaxial loading test data, and the calibrated model can predict the material behavior under multiaxial loading conditions. Biaxial loading and triaxial loading test data are used to verify the proposed model, and parametric analyses are performed to analyze model predictions under different loading conditions. It shows that model predictions agree well with the test data and are consistent with experimental observations.

Microstructure Evolution and Tensile Properties of Medium Manganese Steel Heat Treated by Two-Step Annealing

In this paper, the nucleation and growth of austenite are controlled through a two-step annealing process to achieve multi-scale distribution and content increase of retained austenite in low manganese series medium-Mn steel. Combining SEM, EBSD, AES, and other experimental equipment, the evolution rules of the microstructure, properties, and element distribution behavior of the test steel during the annealing process are studied. Compared with one-step annealing, the two-step annealing significantly broadens the size distribution range of retained austenite. In the first step, after annealing at a higher intercritical temperature (760 °C), the ferrite and the M/A island are obtained, completing the initial partition of Mn and the refinement of microstructures. During the second step of annealing (720 °C), the primary Mn-rich martensite region provides higher nucleation driving force and finer dispersed nucleation sites, promoting the nucleation and growth of reverse transformation austenite. At the same time, the metastable-retained austenite formed after the first step of annealing continues to grow through interface movement. Furthermore, a high proportion (23.4%) of retained austenite with multi-scale distribution is formed in the final microstructure, and the product of strength and elongation increased from 21.8 GPa·% by the one-step annealing process to 30.1 GPa·%.

Critical state uniqueness of dense granular materials using discrete element method in conjunction with flexible membrane boundary

An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method (DEM) under flexible boundary loading conditions. A series triaxial drainage shear test (DEM simulations), in conjunction with the flexible boundary technique, of were performed for sand samples subjected to various physical states and with different particle size distributions. After carefully investigating the critical status of the results of the numerical calculation, the macroscopic failure modes and shear band evolution of sand, as well as the velocity vector field due to different initial states, were explored and classified. Furthermore, the evaluation rules and discrepancies between overall void ratios of the specimen and local void ratios within the shear band under the critical state were recorded and analyzed. The results proved that a sample with a small void tends to form a shear band, and the rotation of the particles in the non-shear zone is negligible. Conversely, sandy soil with large initial void ratios exhibited limited development of significant shear bands, and the change in void ratios within the shear region and the non-shear area are not significant. Interestingly, the particle-size distribution exerts minimal influence on the evolution rule which the void ratio converges within the shear band and diverges outside the shear region for both multi-stage and single-stage specimens. The void ratio within the shear band and deviator stress ratio tend to exhibit consistently for the same specimen with different initial physical states, thereby distinguishing the critical state. There is a significantly higher change in void ratio within the shear band compared to outside of it, yet it remains stable within a relatively similar range. Additionally, the invariant of the fabric tensor used to describe the critical state characteristics also demonstrates a high degree of consistency within the shear band. These findings strongly indicate that the critical state exists within the shear failure surface and is highly likely to be unique.

Analysis of the temperature rise process of carbon ceramic axle-mounted brake disc

Abstract At present, high-speed train braking modules gradually adopt carbon ceramic brake discs. Based on the calculation results, the temperature simulation calculation of carbon ceramic brake disc for high-speed trains is of important engineering reference value for design and application. This paper established a finite element thermal simulation model based on the material properties of carbon-ceramic composite materials and the size and structural characteristics of the brake disc, and conducted a simulation analysis of the 400km/h emergency braking condition. After calculation, the carbon ceramic disc surface temperature reaches about 1250°C during the braking process, which does not exceed the material limit of 1350°C, and can adapt to the braking requirements of high-speed trains. The evolution rules of the temperature field and temperature value changes of the carbon ceramic shaft-mounted brake disc were further studied, and the general rules of disc temperature changes during emergency braking at 400km/h were summarized. The relevant content can provide a reference for the thermal analysis research of carbon ceramic axle-mounted brake disc.

New ideas for the development of acupuncture and moxibustion under the background of medicine-engineering translation.

With the increasing value of translational medicine and medical engineering in the medical field, the collaborative innovation of acupuncture and engineering has become a trend. The mode and concept of the discipline of medicine-engineering junction can promote the development of translational research with acupuncture characteristics, including the rule of syndrome evolution, the application of meridians and acupoints, the exploration of treatment methods, the research of effect mechanism and the innovation of diagnosis and treatment. This paper put forward the future underlying research ideas, the existing questions and challenges for medicine-engineering junction, so as to provide the evidences for the clinical promotion of "combination of medicine and engineering" in the application of modern acupuncture and moxibustion.

Dynamic decisions of the manufacturer-led closed-loop supply chain considering altruistic behavior in EV battery

Behavioral studies have found that altruism can affect the decision of Closed-Loop Supply Chain (CLSC) significantly. Altruistic behaviors on optimal decision-making in dynamic environments are challenging problems. To solve these difficulties, we individually propose three types of cases and using differential game theory and Bellman theory: (a) a manufacturer behaving altruistically to third-party recyclers; (b) one manufacturer cooperating with other participants to have altruism; (c) the manufacturer collaborating with other participants to behave non-altruistically. We conduct optimal dynamic decisions for participants associated with quality of EV batteries, further explore the rule of time evolution considering altruistic behavior. We find three interesting results as follows: altruistic behavior of the manufacturer is advantageous to profitability of CLSC especially when it cooperates with a retailer and one of third-party recyclers. Altruistic behavior of the manufacturer is a behavior of “profit transferring” and moderate altruistic behavior is conducive to the profitability of CLSC and cooperation motivates activity of recycling. In dynamic situations, quality level of EV batteries is polarized. When the manufacturer has altruistic behavior to one or two third-party recyclers, long-term development of CLSC is affected by the deterioration of quality level of EV batteries.

Research on water resources collaborative utilization based on complex networks: A case study of the Han River Basin

As China's social economy grows and the demand for water resources increases, the Han River Basin faces intensified supply-demand conflicts, reducing water resource utilization efficiency and threatening regional development. To address this, a network evolutionary game model based on complex network and evolutionary game theory was developed for collaborative water resource utilization. The study identified key dynamic factors influencing the game in the Han River Basin and analyzed its evolutionary rules. Simulations revealed that the profit-loss ratio and profit distribution rate significantly affect cooperative behavior. Furthermore, the network's topology exhibits small-world characteristics, and factors such as economic preferences, income distribution, and reward-punishment coefficients critically influence cooperation. Considering the current state of water resources and economic development, it is projected that comprehensive cooperation in the basin may take around 11 years to establish.

Evolution of macromolecular structure during coal oxidation via FTIR, XRD and Raman

The analysis of the macromolecular structure and morphology in coal during oxidation is the basis to explore the mechanism of spontaneous combustion. To explore the evolutionary rules of coal macromolecular structure during oxidation, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Raman Spectroscopy (Raman) were employed to analyze the coal samples with different oxidation degrees. The results revealed that the oxidation action led to the decrease of the aliphatic structures and aromatic hydroxyl groups in coal, while promoting the formation of oxygen-containing functional groups and aromatic structures. It also led to a relative increase of free hydroxyl groups linked to hydrogen bonds. The aromatic layer spacing (d002) decreased with increasing oxidation degree, while the microcrystal stacking height (Lc), the aromatic layer diameter (La), the average number of crystal stacking layers (n) generally increased. It indicated that small aromatic ring molecules in coal could undergo continuous polymerization during oxidation to form a single aromatic layer structure. The variation of Raman spectrum parameters exhibited a consistent decreasing trend in WD/WG, ID/IG, AD/AG, and A(GR+SL)/AG value, indicating an increase in the vibration of sp2 hybridization carbon atoms within the lattice structure of coal. Conversely, PG-D, AS/AD and A(GR+VL+VR)/AD value increased overall, suggesting that small aromatic rings decreased in content during oxidation while polymerizing into larger aromatic rings. The coal structure underwent a brief stage of disordered evolution during oxidation, followed by removal of impurity structures and condensation of aromatic structures due to increasing oxidation temperatures, ultimately leading to a highly ordered crystalline state. The oxidation process significantly influenced the development of coal's aromatic structure, particularly in less metamorphic coal. The research findings provide a theoretical basis for analyzing the underlying mechanism behind spontaneous combustion induced by coal oxidation.

Cellular gradient algorithm for solving complex mechanical optimization design problems

In mechanical optimization design problems, there are often some non-continuous or non-differentiable objective functions. For these non-continuous and non-differentiable optimization objectives, it is often difficult for existing optimal design algorithms to find the desired optimal solutions. In this paper, we incorporate the idea of gradient descent into cellular automata and propose a Cellular Gradient (CG) method. First, we have given the basic rules and algorithmic framework of CG and designed three kinds of growth and extinction rules respectively. Then, the three evolutionary rules for cellular within a single cycle are analyzed separately for form and ordering. The best expressions for the cellular jealous neighbor rule and the solitary regeneration rule are given, and the most appropriate order in which the rules are run is selected. Finally, the solution results of the cellular gradient algorithm and other classical optimization design algorithms are compared with a multi-objective multi-parameter mechanical optimization design problem as an example. The computational results show that the cellular gradient algorithm has an advantage over other algorithms in solving global and dynamic mechanical optimal design problems. The novelty of CG is to provide a new way of thinking for solving optimization problems with global discontinuities.

Pore structure evolution of organic-rich shale induced by structural deformation based on shale deformation experiments

The effect of structural deformation on shale pore structure is a key scientific problem in the development of shale gas resources in structurally complex areas. In this study, we investigated the evolution rules and mechanisms of pore structures in organic-rich shale subjected to structural deformation of varying mechanisms and intensities, by conducting whole-aperture pore structure characterization on experimentally deformed shale rather than naturally deformed shale. Results showed that brittle deformed samples developed more mesopores, macropores, and fracture pores. The inter-granular pores between mineral fragments and the inter-layer pores and micro-fractures were the primary sources of the increased pore structures. The ductile deformation of shale promoted large-aperture transitional pores, mesopores, and small-aperture macropores but was adverse to small-aperture transitional pores, large-aperture macropores, and fracture pores. The primary contributors to the enhanced pore structures were inter-granular pores and inter-layer micro-fractures formed during crumpled deformation and inter-layer sliding of clay minerals, and inter-granular pores caused by the grinding, rounding, and rotation of mineral fragments under the flow deformation of the shale matrix. The irreversible compression of organic matter pores, mineral-related pores, and pre-existing large-aperture pores and fractures was the main reason for the reduction in small-aperture transitional pores, large-aperture macropores, and fracture pores.