Microstructure-based three-dimensional characterization of chip formation and surface generation in the machining of particulate-reinforced metal matrix composites

Particulate-reinforced metal matrix composites(PRMMCs)are difficult to machine due to the inclusion of hard,brittle reinforcing particles.Existing experimental investigations rarely reveal the complex material removal mechanisms(MRMs)involved in the machining of PRMMCs.This paper develops a three-dimensional(3D)microstructure-based model for investigating the MRM and surface integrity of machined PRMMCs.To accurately mimic the actual microstructure of a PRMMC,polyhedrons were randomly distributed inside the matrix to represent irregular SiC particles.Particle fracture and matrix deformation and failure were taken into account.For the model’s capability comparison,a two-dimensional(2D)analysis was also conducted.Relevant cutting experiments showed that the established 3D model accurately predicted the material removal,chip morphology,machined surface finish,and cutting forces.It was found that the matrix-particle-tool interactions led to particle fractures,mainly in the primary shear and secondary deformation zones along the cutting path and beneath the machined surface.Particle fracture and dilodegment greatly influences the quality of a machined surface.It was also found that although a 2D model can reflect certain material removal features,its ability to predict microstructural variation is limited.

Recent advances of metal vacancies in energy and environmental catalysis:Synthesis,characterization,and roles

With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.

Experimental investigation of methane explosion fracturing in bedding shales:Load characteristics and three-dimensional fracture propagation

Methane in-situ explosion fracturing(MISEF)enhances permeability in shale reservoirs by detonating desorbed methane to generate detonation waves in perforations.Fracture propagation in bedding shale under varying explosion loads remains unclear.In this study,prefabricated perforated shale samples with parallel and vertical bedding are fractured under five distinct explosion loads using a MISEF experimental setup.High-frequency explosion pressure-time curves were monitored within an equivalent perforation,and computed tomography scanning along with three-dimensional reconstruction techniques were used to investigate fracture propagation patterns.Additionally,the formation mechanism and influencing factors of explosion crack-generated fines(CGF)were clarified by analyzing the morphology and statistics of explosion debris particles.The results indicate that methane explosion generated oscillating-pulse loads within perforations.Explosion characteristic parameters increase with increasing initial pressure.Explosion load and bedding orientation significantly influence fracture propagation patterns.As initial pressure increases,the fracture mode transitions from bi-wing to 4–5 radial fractures.In parallel bedding shale,radial fractures noticeably deflect along the bedding surface.Vertical bedding facilitates the development of transverse fractures oriented parallel to the cross-section.Bifurcation-merging of explosioninduced fractures generated CGF.CGF mass and fractal dimension increase,while average particle size decreases with increasing explosion load.This study provides valuable insights into MISEF technology.

Characterization of three-dimensional channel reservoirs using ensemble Kalman filter assisted by principal component analysis

Ensemble-based analyses are useful to compare equiprobable scenarios of the reservoir models.However,they require a large suite of reservoir models to cover high uncertainty in heterogeneous and complex reservoir models.For stable convergence in ensemble Kalman filter(EnKF),increasing ensemble size can be one of the solutions,but it causes high computational cost in large-scale reservoir systems.In this paper,we propose a preprocessing of good initial model selection to reduce the ensemble size,and then,EnKF is utilized to predict production performances stochastically.In the model selection scheme,representative models are chosen by using principal component analysis(PCA)and clustering analysis.The dimension of initial models is reduced using PCA,and the reduced models are grouped by clustering.Then,we choose and simulate representative models from the cluster groups to compare errors of production predictions with historical observation data.One representative model with the minimum error is considered as the best model,and we use the ensemble members near the best model in the cluster plane for applying EnKF.We demonstrate the proposed scheme for two 3D models that EnKF provides reliable assimilation results with much reduced computation time.

Efficient three-dimensional characterization of C/C composite reinforced with densely distributed fibers via X-ray phase-contrast microtomography

Carbon fiber(CF)/pyrolytic graphite(PG) composites are promising structural materials for molten salt reactors because of their superior performance.Due to the minor density difference between CF and PG, existing methods are impractical for efficient three-dimensional characterization of CF/PG composites.Therefore, in this study, a method based on in-line phasecontrast X-ray microtomography was developed to solve the aforementioned problem.Experimental results demonstrate that the method is suitable for comprehensive characterization of CF/PG composites.The relationship between the microporous defects and fiber orientations of such composites was also elucidated.The findings can be useful for improving the manufacturing process of CF/PG composites.

Visual representation and characterization of three-dimensional hydrofracturing cracks within heterogeneous rock through 3D printing and transparent models

The heterogeneity of unconventional reservoir rock tremendously affects its hydrofracturing behavior. A visual representation and accurate characterization of the three-dimensional （3D） growth and distribution of hydrofracturing cracks within heterogeneous rocks is of particular use to the design and implementation of hydrofracturing stimulation of unconventional reservoirs. However, because of the difficulties involved in visually representing and quantitatively characterizing a 3D hydrofracturing crack-network, this issue remains a challenge. In this paper, a novel method is proposed for physically visualizing and quantitatively characterizing the 3D hydrofracturing crack-network distributed through a heterogeneous structure based on a natural glutenite sample. This method incorporates X-ray microfocus computed tomography （μCT）, 3D printing models and hydrofracturing triaxial tests to represent visually the heterogeneous structure, and the 3D crack growth and distribution within a transparent rock model during hydrofracturing. The coupled effects of material heterogeneity and confining geostress on the 3D crack initiation and propagation were analyzed. The results indicate that the breakdown pressure of a heterogeneous rock model is significantly affected by material heterogeneity and confining geostress. The measured breakdown pressures of heterogeneous models are apparently different from those predicted by traditional theories. This study helps to elucidate the quantitative visualization and characterization of the mechanism and influencing factors that determine the hydrofracturing crack initiation and propagation in heterogeneous reservoir rocks.

A Novel Three-dimensional Ni Coordination Polymer Based on Flexible Di-carboxylate Ligand and 4,4′-Pyridine: Synthesis, Characterization and Topological Analysis

A novel Ni（II） coordination polymer [Ni（dtba）（4,4′-bpy）] （1, H2dtba = 2,2′-dithio- bisbenzoic acid, 4,4′-bpy = 4,4′-bipyridine） has been synthesized by H2dtba and Ni（CH3COO）2·4H2O with exo-bidentate rigid ligand 4,4′-bpy by using hydrothermal method, and its structure was determined by single-crystal X-ray diffraction. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic, space group Cc with a = 11.7624（9）, b = 18.7933（19）, c = 10.3071（11）, β = 97.6510（10）°, V = 2258.2（4）3, Z = 4, C24H16N2NiO4S2, Mr = 519.22, Dc = 1.527 g/cm3, μ = 1.079 mm-1 and F（000） = 1064. The structure was solved by direct methods and refined to R = 0.0434 and wR = 0.1000 for 3281 observed reflections （I 〉 2σ（I））. The coordination environment of Ni（II） is a distorted octahedron, and a three-dimensional structure was formed with the coordination effect of dtba2- and 4,4′-bpy ligands. The topological analysis reveals that the whole framework of 1 is a 2-nodal net of （52.6）（53.64.72.8） topology. The thermal stability and XRD pattern of 1 were also investigated

Three-dimensional characterization of micro-fractures in shale reservoir rocks

Fractures are crucial for unconventional hydrocarbon exploitation,but it is difficult to accurately observe the 3D spatial distribution characteristics of fractures.Microtomography(micro-CT)technology makes it possible to observe the 3D structures of fractures at micro-scale.In this study,micron-CT scanning is conducted on multiple mud-shale samples of source rocks in the Permian Lucaogou Formation,Junggar Basin.The Avizo^(®) software is applied to process and segment the micron-CT images,so as to obtain the 3D fracture structure model inside rock core.Therefore,the independently-developed CTSTA program is adopted to quantitatively describe the micro-fractures inside rock core,including fracture dimension,extension direction and extension scale.Meanwhile,this study summarizes the classification characteristics of fractures and their anisotropy.On this basis,the fractal dimensions of fractures can also be extracted.Previous studies show that the geometric features of fractures have self-similarity at large and small scales,which can be described by exponential laws;and the fractal dimension is a typical exponent.Through the quantitative description or characterization of 3D fractures at micro-scale,the distribution characteristics of fractures in large scales could be known.

Lithological Characterization and Its Application Based on Three-Dimensional Structure-Coupled Joint Inversion of Gravity and Magnetic Data

Incorporating structural-coupling constraint, known as the cross-gradients criterion, helps to improve the focussing trend in cross-plot of multiple physical properties. Based on this feature, a?post-processing technique is studied to characterize the lithological types of subsurface geological materials after joint inversion. A simple domain transform, which converts two kinds of participant physical properties into an artificial complex array, is adopted to extract anomalies manually from homogenous host rock. A synthetic example shows that structure-coupled joint inverted results tend to concentrate on the feature trends in the cross-plot, and the main geological targets are recovered well by a radius-azimuth plot. In a field data example, the lithological characterization?reveals that the main rock types interpreted in the study area agree with the geological information, thus demonstrating the feasibility of this technique.

Synthesis and Structural Characterization of One New Polyoxotungstate Connected via Potassium Cations with aThree-dimensional Framework: H_6Na_2K_4(H_2W_(12)O_(42))Cl_2·14H_2O

One new polyoxotungstate complex H6Na2K4（H2W12O42）Cl2·14H2O 1 has been prepared in the beaker solution and characterized by elemental analysis and IR spectroscopy. Crystal data： H36Cl2K4W12Na2O56, Mr = 3411.77, monoclinic, space group P21/c, a = 11.5734（16）, b = 14.3136（19）, c = 15.459（2）A, β = 105.601（2）°, V = 2466.5（6）A^3, Z = 2, Dc = 4.594 g/cm^3, F（000） = 3008, μ = 28.447 mm^-1, R = 0.0574 and wR = 0.1239 （Ⅰ〉 2σ（Ⅰ））. Single-crystal X-ray diffraction analysis results reveal that a three-dimensional architecture in the title compound is constructed from the H2W12O42^10- units linked by potassium.

Characterization, preparation, and reuse of metallic powders for laser powder bed fusion: a review

Laser powder bed fusion(L-PBF) has attracted significant attention in both the industry and academic fields since its inception, providing unprecedented advantages to fabricate complex-shaped metallic components. The printing quality and performance of L-PBF alloys are infuenced by numerous variables consisting of feedstock powders, manufacturing process,and post-treatment. As the starting materials, metallic powders play a critical role in infuencing the fabrication cost, printing consistency, and properties. Given their deterministic roles, the present review aims to retrospect the recent progress on metallic powders for L-PBF including characterization, preparation, and reuse. The powder characterization mainly serves for printing consistency while powder preparation and reuse are introduced to reduce the fabrication costs.Various powder characterization and preparation methods are presented in the beginning by analyzing the measurement principles, advantages, and limitations. Subsequently, the effect of powder reuse on the powder characteristics and mechanical performance of L-PBF parts is analyzed, focusing on steels, nickel-based superalloys, titanium and titanium alloys, and aluminum alloys. The evolution trends of powders and L-PBF parts vary depending on specific alloy systems, which makes the proposal of a unified reuse protocol infeasible. Finally,perspectives are presented to cater to the increased applications of L-PBF technologies for future investigations. The present state-of-the-art work can pave the way for the broad industrial applications of L-PBF by enhancing printing consistency and reducing the total costs from the perspective of powders.

A theory for three-dimensional response of micropolar plates

Through combined applications of the transfer-matrix method and asymptotic expansion technique,we formulate a theory to predict the three-dimensional response of micropolar plates.No ad hoc assumptions regarding through-thickness assumptions of the field variables are made,and the governing equations are two-dimensional,with the displacements and microrotations of the mid-plane as the unknowns.Once the deformation of the mid-plane is solved,a three-dimensional micropolar elastic field within the plate is generated,which is exact up to the second order except in the boundary region close to the plate edge.As an illustrative example,the bending of a clamped infinitely long plate caused by a uniformly distributed transverse force is analyzed and discussed in detail.

Three-dimensional visualization technology for guiding one-step percutaneous transhepatic cholangioscopic lithotripsy for the treatment of complex hepatolithiasis

BACKGROUND Biliary stone disease is a highly prevalent condition and a leading cause of hospitalization worldwide.Hepatolithiasis with associated strictures has high residual and recurrence rates after traditional multisession percutaneous transhepatic cholangioscopic lithotripsy(PTCSL).AIM To study one-step PTCSL using the percutaneous transhepatic one-step biliary fistulation(PTOBF)technique guided by three-dimensional(3D)visualization.METHODS This was a retrospective,single-center study analyzing,140 patients who,between October 2016 and October 2023,underwent one-step PTCSL for hepatolithiasis.The patients were divided into two groups:The 3D-PTOBF group and the PTOBF group.Stone clearance on choledochoscopy,complications,and long-term clearance and recurrence rates were assessed.RESULTS Age,total bilirubin,direct bilirubin,Child-Pugh class,and stone location were similar between the 2 groups,but there was a significant difference in bile duct strictures,with biliary strictures more common in the 3D-PTOBF group(P=0.001).The median follow-up time was 55.0(55.0,512.0)days.The immediate stone clearance ratio(88.6%vs 27.1%,P=0.000)and stricture resolution ratio(97.1%vs 78.6%,P=0.001)in the 3D-PTOBF group were significantly greater than those in the PTOBF group.Postoperative complication(8.6%vs 41.4%,P=0.000)and stone recurrence rates(7.1%vs 38.6%,P=0.000)were significantly lower in the 3D-PTOBF group.CONCLUSION Three-dimensional visualization helps make one-step PTCSL a safe,effective,and promising treatment for patients with complicated primary hepatolithiasis.The perioperative and long-term outcomes are satisfactory for patients with complicated primary hepatolithiasis.This minimally invasive method has the potential to be used as a substitute for hepatobiliary surgery.

Oxygen tension modulates cell function in an in vitro three-dimensional glioblastoma tumor model

Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.

Three-dimensional cell-based strategies for liver regeneration

Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern medicine.In recent years,the utilization of 3D cell-based strategies has emerged as a promising approach for addressing these urgent clinical requirements.This review provides a thorough analysis of the application of 3D cell-based approaches to liver regeneration and their potential impact on patients with end-stage liver failure.Here,we discuss various 3D culture models that incorporate hepatocytes and stem cells to restore liver function and ameliorate the consequences of liver failure.Furthermore,we explored the challenges in transitioning these innovative strategies from preclinical studies to clinical applications.The collective insights presented herein highlight the significance of 3D cell-based strategies as a transformative paradigm for liver regeneration and improved patient care.

Three novel umami peptides derived from the alcohol extract of the Pacific oyster(Crassostrea gigas):identification,characterizations and interactions with T1R1/T1R3 taste receptors

Oyster(Crassostrea gigas),the main ingredient of oyster sauce,has a strong umami taste.In this study,three potential umami peptides,FLNQDEEAR(FR-9),FNKEE(FE-5),and EEFLK(EK-5),were identified and screened from the alcoholic extracts of the oyster using nano-HPLC-MS/MS analysis,i Umami-Scoring Card Method(i Umami-SCM)database and molecular docking(MD).Sensory evaluation and electronic tongue analysis were further used to confirm their tastes.The threshold of the three peptides ranged from 0.38 to 0.55 mg/m L.MD with umami receptors T1R1/T1R3 indicated that the electrostatic interaction and hydrogen bond interaction were the main forces involved.Besides,the Phe592 and Gln853 of T1R3 were the primary docking site for MD and played an important role in umami intensity.Peptides with two Glu residues at the terminus had stronger umami,especially at the C-terminus.These results contribute to the understanding of umami peptides in oysters and the interaction mechanism between umami peptides and umami receptors.

Genome-wide identification,characterization and functional prediction of the SRS gene family in sesame(Sesamum indicum L.)

Sesame(Sesamum indicum L.)is an ancient oilseed crop of the Pedaliaceae family with high oil content and potential health benefits.SHI RELATED SEQUENCE(SRS)proteins are the transcription factors(TFs)specific to plants that contain RING-like zinc finger domain and are associated with the regulation of several physiological and biochemical processes.They also play vital roles in plant growth and development such as root formation,leaf development,floral development,hormone biosynthesis,signal transduction,and biotic and abiotic stress responses.Nevertheless,the SRS gene family was not reported in sesame yet.In this study,identification,molecular characterization,phylogenetic relationship,cis-acting regulatory elements,protein-protein interaction,syntenic relationship,duplication events and expression pattern of SRS genes were analyzed in S.indicum.We identified total six SiSRS genes on seven different linkage groups in the S.indicum genome by comparing with the other species,including the model plant Arabidopsis thaliana.The SiSRS genes showed variation in their structure like2–5 exons and 1–4 introns.Like other species,SiSRS proteins also contained‘RING-like zinc finger'and‘LRP1'domains.Then,the SiSRS genes were clustered into subclasses via phylogenetic analysis with proteins of S.indicum,A.thaliana,and some other plant species.The cis-acting regulatory elements analysis revealed that the promoter region of SiSRS4(SIN_1011561)showed the highest 13 and 16 elements for light-and phytohormone-responses whereas,SiSRS1(SIN_1015187)showed the highest 15 elements for stress-response.The ABREs,or ABA-responsive elements,were found in a maximum of 8 copies in the SiSRS3(SIN 1009100).Moreover,the available RNA-seq based expression of SiSRS genes revealed variation in expression patterns between stress-treated and non-treated samples,especially in drought and salinity conditions in.S.indicum.Two SiSRS genes like SiSRS1(SIN_1015187)and SiSRS5(SIN_1021065),also exhibited variable expression patterns between control vs PEG-treated sesame root samples and three SiSRS genes,including SiSRS1(SIN_1015187),SiSRS2(SIN_1003328)and SiSRS5(SIN_1021065)were responsive to salinity treatments.The present outcomes will encourage more research into the gene expression and functionality analysis of SiSRS genes in S.indicum and other related species.

Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system

Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.