Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network

Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantitative parameters.However,due to the harsh on-site construction conditions,it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality prediction.In this study,a novel improved Swin Transformer is proposed to detect,segment,and quantify rock mass characteristic parameters such as water leakage,fractures,weak interlayers.The site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%,81%,and 86%for water leakage,fractures,and weak interlayers,respectively.A multisource rock tunnel face characteristic(RTFC)dataset includes 11 parameters for predicting rock mass quality is established.Considering the limitations in predictive performance of incomplete evaluation parameters exist in this dataset,a novel tree-augmented naive Bayesian network(BN)is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%.In comparison with other commonly used Machine Learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete dataset.By utilizing the established BN,a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters,results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality.

Accelerated Primal-Dual Projection Neurodynamic Approach With Time Scaling for Linear and Set Constrained Convex Optimization Problems

The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on unconstrained smooth con-vex optimization problems.In this paper,on the basis of primal-dual dynamical approach,Nesterov accelerated dynamical approach,projection operator and directional gradient,we present two accelerated primal-dual projection neurodynamic approaches with time scaling to address convex optimization problems with smooth and nonsmooth objective functions subject to linear and set constraints,which consist of a second-order ODE(ordinary differential equation)or differential conclusion system for the primal variables and a first-order ODE for the dual vari-ables.By satisfying specific conditions for time scaling,we demonstrate that the proposed approaches have a faster conver-gence rate.This only requires assuming convexity of the objective function.We validate the effectiveness of our proposed two accel-erated primal-dual projection neurodynamic approaches through numerical experiments.

Slaughter Performance, Muscle Quality and Nutritional Composition of Duoluo Goats in Sichuan Province

[Objectives] This study was conducted to understand the biological characteristics of Duoluo goats. [Methods] With male and female Duoluo goats as the research object, related performance indexes were determined and analyzed after slaughter. [Results] The weights of one-year-old male and female Duoluo goats before slaughter were (25.68±2.37) and (24.51±1.97) kg, respectively;the dressing percentages were (43.55±3.24) % and (43.84±3.42) %, respectively;and the net meat percentages were (33.02±2.32) % and (34.19±2.46) %, respectively. (2) The cooked meat rates of male and female Duoluo goats were (65.49±1.42) % and (65.36±1.55) %, respectively;the shearing force was (5.48±1.24) and (5.65±1.02) N, respectively;and the loin-eye muscle areas were (8.95±1.72) and (8.82±1.15) cm 2, respectively. (3) The protein contents of male and female Duoluo goats were (20.07±0.42) and (19.47±1.22) g/100 g, respectively;and the fat contents were (1.30±0.80) % and (2.92±0.55) %, respectively;and the cholesterol contents were (71.76±11.47) and (74.83±2.68) mg/100 g, respectively;(4) The Ca contents of male and female Duoluo goats were (69.53±10.89) and (63.00±4.56) mg/kg, respectively;the Fe contents were (16.73±1.83) and (14.77±0.58) mg/kg, respectively;and the Zn contents were (38.47±3.68) and (31.83±2.22) mg/kg, respectively. (5) In the muscles of male and female Duoluo goats, the contents of essential amino acids were (7.44±0.24) and (7.26±0.41) g/100 g , respectively;the contents of non-essential amino acids were (11.81±0.33) and (11.42±0.67) g/100 g, respectively;and the contents of flavor amino acids were (8.79±0.27) and (8.42±0.57) g/100 g, respectively. [Conclusions] This study lays a foundation for the excavation and utilization of the resource, Duoluo goats.

Machine learning-based classification of rock discontinuity trace:SMOTE oversampling integrated with GBT ensemble learning

This paper presents a hybrid ensemble classifier combined synthetic minority oversampling technique(SMOTE),random search(RS)hyper-parameters optimization algorithm and gradient boosting tree(GBT)to achieve efficient and accurate rock trace identification.A thirteen-dimensional database consisting of basic,vector,and discontinuity features is established from image samples.All data points are classified as either‘‘trace”or‘‘non-trace”to divide the ultimate results into candidate trace samples.It is found that the SMOTE technology can effectively improve classification performance by recommending an optimized imbalance ratio of 1:5 to 1:4.Then,sixteen classifiers generated from four basic machine learning(ML)models are applied for performance comparison.The results reveal that the proposed RS-SMOTE-GBT classifier outperforms the other fifteen hybrid ML algorithms for both trace and nontrace classifications.Finally,discussions on feature importance,generalization ability and classification error are conducted for the proposed classifier.The experimental results indicate that more critical features affecting the trace classification are primarily from the discontinuity features.Besides,cleaning up the sedimentary pumice and reducing the area of fractured rock contribute to improving the overall classification performance.The proposed method provides a new alternative approach for the identification of 3D rock trace.

Face stability analysis of circular tunnels in layered rock masses using the upper bound theorem

An analysis of tunnel face stability generally assumes a single homogeneous rock mass.However,most rock tunnel projects are excavated in stratified rock masses.This paper presents a two-dimensional(2D)analytical model for estimating the face stability of a rock tunnel in the presence of rock mass stratification.The model uses the kinematical limit analysis approach combined with the block calculation technique.A virtual support force is applied to the tunnel face,and then solved using an optimization method based on the upper limit theorem of limit analysis and the nonlinear Hoek-Brown yield criterion.Several design charts are provided to analyze the effects of rock layer thickness on tunnel face stability,tunnel diameter,the arrangement sequence of weak and strong rock layers,and the variation in rock layer parameters at different positions.The results indicate that the thickness of the rock layer,tunnel diameter,and arrangement sequence of weak and strong rock layers significantly affect the tunnel face stability.Variations in the parameters of the lower layer of the tunnel face have a greater effect on tunnel stability than those of the upper layer.

Study on Electromagnetic-Fluid-Temperature Multiphysics Field Coupling Model for Drum of Mine Cable Winding Truck

Aiming at solving problems of low efficiency,low cable capacity in current 300m open-pit mine cable winding truck,a 900 m cable winding plan was proposed.In this paper,the mechanism of the thermal effect of the cable was described,and a two-dimensional axisymmetric electromagnetic-fluid-temperature multiphysics coupling model of the cable reel was established regarding the 900m cable reel as independent system.Considering the structure of the drum,the number of cable winding layers,the factors of heat conduction,heat radiation and convective heat transfer in the actual working process,the steady state analysis of the multi-physical field coupling was carried out.The sum of the losses of each part of the cable was obtained through the calculation of electromagnetic field,which was used as a heat source to calculate and analyze the temperature distribution of different layers of cable winding,as well as the temperature distribution and heat dissipation characteristics of different structures of the drum.The results show that three layers of cable winding is the best design.The lowest temperature of closed cylindrical drum is 70℃after heat dissipation,which has obvious advantages compared with the lowest temperature of 85℃after heat dissipation of squirrel-cage cylindrical drum.The results provide a reliable theoretical basis for the research and development of a new type of mine cable winding truck with 900 m cable capacity.

Cloning and Sequence Analysis of IGFBP-7 Gene in Sheep

In this study, full-length CDS sequence of IGFBP-7 gene was cloned from Liangshan semi-fine wool sheep with RT-PCR method and analyzed with bioinformatics methods. The results showed that the full-length CDS sequence of IGFBP-7 gene in Liangshan semi-fine wool sheep was 846 bp in length, encoding 282 amino acids. The CDS sequence shared 99%, 95% and 90% homology with bovine, human and rat, respectively; the amino acid sequence shared 98%, 93% and 89%, respectively. The GenBank accession number was FJ589640.1. The amino acid molecular weight of IGFBP-7 was 29.0 kD, and the theoretical isoelec- tric point （pl） was 8.25. The result of phylogenetic analysis showed that IGFBP-7 gone in Liangshan semi-fine wool sheep exhibited close phylogenetic relationships with bovine, goat and other mammals, and distant phylogenetic relationships with Danio rerio and Haliotis diversicolor. IGFBP-7 gene had uniformly distributed hy- drophobic and hydrophilic regions, harboring one signal peptide, two transmembrane regions, 16 phosphorylation sites, four N-glycosylation sites and one O-glyco- sylation site. The result of secondary structure analysis showed that the random coil, or-helix and β-sheet regions accounted for 64.89%, 19.86% and 15.25%, respectively. The result of tertiary structure analysis showed that IGFBP-7 harbors an IGFBP_N domain and an Ig-like domain. This study provided scientific basis for further investigating the function of IGFBP-7 gene in sheep.

Cloning and Sequence Analysis of IGFBP-1 Gene in Sheep

In this study, using Liangshan semi-fine wool sheep as an experimental material, full-length CDS sequence of IGFBP-1 gene was cloned with RT-PCR method and analyzed with bioinformatics methods. The results showed that the full-length CDS sequence of IGFBP-1 gene in Liangshan semi-fine wool sheep was 792 bp in length, encoding 263 amino acids. The CDS sequence shared 97%, 76% and 74% homology with bovine, human and rat, respectively; the amino acid sequence shared 97% , 69% and 71%, respectively. The GenBank accession number was FJ589639.1. The amino acid molecular weight of IGFBP-1 was 27.8 kD, and the theoretical isoelectric point （pl） was 5.99. The result of phylogenetic analysis showed that IGFBP-1 gene in Liangshan semi-fine wool sheep exhibited close phylogenetic relationships with bovine, goat and other mammals, and distant phylogenetic relationships with chicken and fish. IGFBP-1 gene had obvious hy- drophobic and hydrophilic regions, harboring one signal peptide, one transmembrane region, 16 phosphorylation sites, six N-glycesylation sites and eight O-glycosy- lation sites. The result of secondary structure analysis showed that the random coil, a-helix and 13-sheet regions accounted for 61.98%, 24.33% and 13.69%, re- spectively. The result of tertiary structure analysis showed that IGFBP-1 harbors an IGFBP_N domain and a thyrnglobulin type-1 domain. This study laid a solid foundation for further investigating the function of IGFBP-1 gene in sheep.

Biomineralization inspired 3D printed bioactive glass nanocomposite scaffolds orchestrate diabetic bone regeneration by remodeling micromilieu

TypeⅡdiabetes mellitus(TIIDM)remains a challenging clinical issue for both dentists and orthopedists.By virtue of persistent hyperglycemia and altered host metabolism,the pathologic diabetic micromilieu with chronic inflammation,advanced glycation end products accumulation,and attenuated biomineralization severely impairs bone regeneration efficiency.Aiming to“remodel”the pathologic diabetic micromilieu,we 3D-printed bioscaffolds composed of Sr-containing mesoporous bioactive glass nanoparticles(Sr-MBGNs)and gelatin methacrylate(GelMA).Sr-MBGNs act as a biomineralization precursor embedded in the GelMA-simulated extracellular matrix and release Sr,Ca,and Si ions enhancing osteogenic,angiogenic,and immunomodulatory properties.In addition to angiogenic and anti-inflammatory outcomes,this innovative design reveals that the nanocomposites can modulate extracellular matrix reconstruction and simulate biomineralization by activating lysyl oxidase to form healthy enzymatic crosslinked collagen,promoting cell focal adhesion,modulating osteoblast differentiation,and boosting the release of OCN,the noncollagenous proteins(intrafibrillar mineralization dependent),and thus orchestrating osteogenesis through the Kindlin-2/PTH1R/OCN axis.This 3D-printed bioscaffold provides a multifunctional biomineralization-inspired system that remodels the“barren”diabetic microenvironment and sheds light on the new bone regeneration approaches for TIIDM.

Failure responses of rock tunnel faces during excavation through the fault-fracture zone

It is essential to cast light on the construction risks in tunnel excavations through the fault-fracture zone(FFZ).This study adopts the material point method(MPM)to simulate the failure responses of a rock tunnel face during excavation through the FFZ.A numerical study was conducted to compare a physical model test and validate the feasibility of using the MPM in simulating tunnel face failure.One hundred ninety numerical simulation cases were constructed to represent a rock tunnel excavation project with different site con-figurations.The simulation results suggest that the cohesion and the friction angle significantly influence failure responses.The tunnel cover depth can magnify the failure responses,and the FFZ thickness significantly affects the mobilized rock mass volume when the FFZ consists of a weak rock mass.The numerical simulation results suggest three deformation patterns:face bulge,partial failure,and slide collapse.The failure responses can be characterized by stress arch,slip surface,angle of reposing,and influence range.The insights suggested by the face failure responses during excavation through the FFZ can aid field engineers in determining the scope of possible damage,and in establishing emergency measures to minimize losses if such failure occurs.

Resistance factors for design of slopes in a homogenous soil layer

Traditionally,the factor of safety(FOS)is widely used to account for uncertainties in the design of slopes within the framework of working stress design.As the uncertainties involved in the design of slopes vary,the same FOS may correspond to the different levels of reliability.In this study,the advanced first order reliability method is used to determine the resistance factors for design of slopes in a homogenous soil layer.It is found that the resistance factors depend on the target reliability index,the height of the slope,and the variability of the soil strength parameters.It is difficult to suggest a unique set of resistance factors for design of slopes.Analytic solutions are developed to determine the resistance factors for design of slopes assuming the random variables are normally distributed.An approximate method based on the concept of equivalent target reliability index is also suggested to determine the resistance factors for design of the slope when the soil strength parameters are lognormally distributed.The method suggested in this paper provides a practical way to perform load and resistance factors design of slopes.

Marginal sealing around integral bilayer scaffolds for repairing osteochondral defects based on photocurable silk hydrogels

Osteochondral repair remains a major challenge in current clinical practice despite significant advances in tissue engineering.In particular,the lateral integration of neocartilage into surrounding native cartilage is a difficult and inadequately addressed problem that determines the success of tissue repair.Here,a novel design of an integral bilayer scaffold combined with a photocurable silk sealant for osteochondral repair is reported.First,we fabricated a bilayer silk scaffold with a cartilage layer resembling native cartilage in surface morphology and mechanical strength and a BMP-2-loaded porous subchondral bone layer that facilitated the osteogenic differentiation of BMSCs.Second,a TGF-β3-loaded methacrylated silk fibroin sealant(Sil-MA)exhibiting biocompatibility and good adhesive properties was developed and confirmed to promote chondrocyte migration and differentiation.Importantly,this TGF-β3-loaded Sil-MA hydrogel provided a bridge between the cartilage layer of the scaffold and the surrounding cartilage and then guided new cartilage to grow towards and replace the degraded cartilage layer from the surrounding native cartilage in the early stage of knee repair.Thus,osteochondral regeneration and superior lateral integration were achieved in vivo by using this composite.These results demonstrate that the new approach of marginal sealing around the cartilage layer of bilayer scaffolds with Sil-MA hydrogel has tremendous potential for clinical use in osteochondral regeneration.

Novel SfM-DLT method for metro tunnel 3D reconstruction and Visualization

Metro tunnels play a crucial role in urban transportation.However,with growing tunnel operation periods,defects,and large deformations appearing,these are influencing tunnel structural performance and threatening public safety.Three-dimensional(3D)tunnel reconstruction is an effective way to highlight tunnel conditions and provide a basis for engineering management and maintenance.However,the current methods of tunnel 3D reconstruction do not sufficiently combine the qualitative and quantitative characteristics of tunnel states.In this study,a novel method for metro tunnel 3D reconstruction based on structure from motion(SfM)and direct linear transformation(DLT)is proposed.The dimensionless 3D reconstruction point cloud acquired through the SfM method showcases the qualitative characteristics(such as leakage and pipelines)of the tunnel state.The close-range photogrammetry DLT method provides scale information missing from the SfM method and quantitative characteristics(such as profile deformation)of the tunnel state.The SfM-DLT method was tested in a Shanghai metro tunnel,and proved to be feasible and promising for future tunnel inspections.

Orchestration of energy metabolism and osteogenesis by Mg^(2+)facilitates low-dose BMP-2-driven regeneration

The clinical application of bone morphogenetic protein-2(BMP-2)is limited by several factors,including ineffectiveness at low doses and severe adverse effects at high doses.To address these efficacy and safety limitations,we explored whether orchestration of energy metabolism and osteogenesis by magnesium ion(Mg^(2+))could reduce the dose and thereby improve the safety of BMP-2.Our results demonstrated that rapid metabolic activation triggered by BMP-2 was indispensable for subsequent osteogenesis.Moreover,inadequate metabolic stimulation was shown to be responsible for the ineffectiveness of low-dose BMP-2.Next,we identified that Mg^(2+),as an"energy propellant",substantially increased cellular bioenergetic levels to support the osteogenesis via the Akt-glycolysis-Mrs2-mitochondrial axis,and consequently enhanced the osteoinductivity of BMP-2.Based on the mechanistic discovery,microgel composite hydrogels were fabricated as low-dose BMP-2/Mg^(2+)codelivery system through microfluidic and 3D printing technologies.An in vivo study further confirmed that rapid and robust bone regeneration was induced by the codelivery system.Collectively,these results suggest that this bioenergetic-driven,cost-effective,low-dose BMP-2-based strategy has substantial potential for bone repair.

A rapidly magnetically assembled stem cell microtissue with“hamburger”architecture and enhanced vascularization capacity

With the development of magnetic manipulation technology based on magnetic nanoparticles(MNPs),scaffold-free microtissues can be constructed utilizing the magnetic attraction of MNP-labeled cells.The rapid in vitro construction and in vivo vascularization of microtissues with complex hierarchical architectures are of great importance to the viability and function of stem cell microtissues.Endothelial cells are indispensable for the formation of blood vessels and can be used in the prevascularization of engineered tissue constructs.Herein,safe and rapid magnetic labeling of cells was achieved by incubation with MNPs for 1 h,and ultrathick scaffold-free microtissues with different sophisticated architectures were rapidly assembled,layer by layer,in 5 min intervals.The in vivo transplantation results showed that in a stem cell microtissue with trisection architecture,the two separated human umbilical vein endothelial cell(HUVEC)layers would spontaneously extend to the stem cell layers and connect with each other to form a spatial network of functional blood vessels,which anastomosed with the host vasculature.The“hamburger”architecture of stem cell microtissues with separated HUVEC layers could promote vascularization and stem cell survival.This study will contribute to the construction and application of structural and functional tissues or organs in the future.

Micromixing performance of the teethed high shear mixer under semi-batch operation

Semi-batch operated reaction processes are necessary for some competitive reaction systems to achieve a desirable process selectivity and productivity of fine chemical products.Herein the structural and operating parameters of the teethed high shear mixers were adjusted to study the micromixing performance in the semi-batch operated system,using the Villermaux/Dushman reaction system.The results indicate that the rising of the rotor speed and the number of rotor teeth,the decrease of the width of the shear gap and the radial distance between the feed position and the inner wall of stator can enhance the micromixing level and lead to the decrease of the segregation index.Additionally,computational fluid dynamics calculations were carried out to disclose the evolution of the flow pattern and turbulent energy dissipation rate of the semi-batch operated high shear mixer.Furthermore,the correlation was established with a mean relative error of 8.05%and R^(2)of 0.955 to fit the segregation index and the parameters studied in this work,which can provide valuable guidance on the design and optimization of the semi-batch operated high shear mixers in practical applications.