Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable solutions.Nevertheless,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely explored.This study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic materials.The ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon steel.Although the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

Microstructure evolution of 7050 aluminum forgings during surface cumulative plastic deformation

To elucidate the mechanisms of regulating the microstructure uniformity in 7050 aluminum forgings through surface cumulative plastic deformation(SCPD),the microstructure under different solution treatments was investigated using metallographic observation(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and X-ray diffraction(XRD).The findings demonstrate that the most uniform microstructure in the forgings is achieved with a solution treatment at 470℃for 30 min.The SCPD process generates a significant number of needle-shaped precipitates,resulting in a higher dislocation density and stored energy.Solution treatments alleviate the pinning effect of second-phase particles and facilitate static recrystallization(SRX)in forgings,leading to a reduction in grain size.Additionally,mechanical testing results demonstrate 7%−13%increase in tensile strength and more uniform elongation of the forgings in different directions.

Plastic deformation mechanism of γ-phase U–Mo alloy studied by molecular dynamics simulations

Uranium–molybdenum(U–Mo) alloys are critical for nuclear power generation and propulsion because of their superior thermal conductivity, irradiation stability, and anti-swelling properties. This study explores the plastic deformation mechanisms of γ-phase U–Mo alloys using molecular dynamics(MD) simulations. In the slip model, the generalized stacking fault energy(GSFE) and the modified Peierls–Nabarro(P–N) model are used to determine the competitive relationships among different slip systems. In the twinning model, the generalized plane fault energy(GPFE) is assessed to evaluate the competition between slip and twinning. The findings reveal that among the three slip systems, the {110}<111>slip system is preferentially activated, while in the {112}<111> system, twinning is favored over slip, as confirmed by MD tensile simulations conducted in various directions. Additionally, the impact of Mo content on deformation behavior is emphasized. Insights are provided for optimizing process conditions to avoid γ → α′′ transitions, thereby maintaining a higher proportion of γ-phase U–Mo alloys for practical applications.

An extended discontinuous deformation analysis for simulation of grouting reinforcement in a water-rich fractured rock tunnel

Grouting has been the most effective approach to mitigate water inrush disasters in underground engineering due to its ability to plug groundwater and enhance rock strength.Nevertheless,there is a lack of potent numerical tools for assessing the grouting effectiveness in water-rich fractured strata.In this study,the hydro-mechanical coupled discontinuous deformation analysis(HM-DDA)is inaugurally extended to simulate the grouting process in a water-rich discrete fracture network(DFN),including the slurry migration,fracture dilation,water plugging in a seepage field,and joint reinforcement after coagulation.To validate the capabilities of the developed method,several numerical examples are conducted incorporating the Newtonian fluid and Bingham slurry.The simulation results closely align with the analytical solutions.Additionally,a set of compression tests is conducted on the fresh and grouted rock specimens to verify the reinforcement method and calibrate the rational properties of reinforced joints.An engineering-scale model based on a real water inrush case of the Yonglian tunnel in a water-rich fractured zone has been established.The model demonstrates the effectiveness of grouting reinforcement in mitigating water inrush disaster.The results indicate that increased grouting pressure greatly affects the regulation of water outflow from the tunnel face and the prevention of rock detachment face after excavation.

Deformation mechanism and NPR anchor cable truss coupling support in tunnel through fault fracture zone

To address the issue of extensive deformation in the Tabaiyi Tunnel caused by the fault zone,nuclear magnetic resonance(NMR)technology was employed to analyze the physical and mechanical properties of waterabsorbing mudstone.This analysis aimed to understand the mechanism behind the significant deformations.Drawing from the principle of excavation stress compensation,a support scheme featuring NPR anchorcables and an asymmetric truss support system was devised.To validate the scheme,numerical analysis using a combination of the Discrete Element Method(DEM)-Finite Element Method(FEM)was conducted.Additionally,similar material model tests and engineering measurements were carried out.Field experiments were also performed to evaluate the NPR anchor-cable and truss support system,focusing on anchor cable forces,pressures between the truss and surrounding rock,pressures between the initial support and secondary lining,as well as the magnitude of settlement and convergence deformation in the surrounding rock.The results indicate that the waterinduced expansion of clay minerals,resulting from damage caused by fissure water,accelerated the softening of the mudstone's internal structure,leading to significant deformations in the Tabaiyi Tunnel under high tectonic stress.The original support design fell short as the length of the anchor rods was smaller than the expansion depth of the plastic zone.As a result,the initial support structure bore the entire load from the surrounding rock,and a non-coupled deformation contact was observed between the double-arch truss and the surrounding rock.The adoption of NPR asymmetric anchor-cable support effectively restrained the expansion and asymmetric distribution characteristics of the plastic zone.Considering the mechanical degradation caused by water absorption in mudstone,the rigid constraint provided by the truss proved crucial for controlling the stability of the surrounding rock.These research findings hold significant implications for managing large deformations in soft rock tunnels situated within fractured zones under high tectonic stress conditions.

基于改进Deformable-DETR的水下图像目标检测方法

针对由于水下复杂环境造成的目标检测效果较差、检测精度较低的问题,基于Deformable-DETR算法提出一种改进的水下目标检测算法Deformable-DETR-DA。使用空间注意力模块结合标准Transformer块设计了一个用于增加模型深度的深度特征金字塔(deep feature pyramid networks,DFPN)模块,将其嵌入到模型中提高模型对深层纹理信息的提取能力。使用注意力引导的方式对原模型中编码器部分进行改进,加强了对特征信息的聚合能力,提高了模型在复杂环境下的检测能力。针对URPC数据集,模型各交并比尺度的平均准确度(average precision,AP)为39.5%,相比原模型提升1%,与一些DETR(detection transformer)类的模型相比,不同目标尺度的平均准确度均有1%~4%左右的提高,表明改进的模型能够很好解决复杂环境的水下目标检测的问题。本文提出的模型可作为其他水下目标检测模型设计的参考。

基于Deform 3D的AZ31镁合金不对称挤压变形工艺模拟

通过Deform 3D软件模拟了AZ31镁合金不对称挤压变形工艺过程。结果表明,设置不同水平长度流动距离促使材料不对称地流入挤压通道,进而形成不对称剪切变形,出现应变及应力集中分布的不对称性,促使材料晶粒沿着剪切面偏转,获得细晶、弱织构的高性能镁合金坯料。

Transcranial surgery through pterional approach for removal of cranio-orbital tumors by an interdisciplinary team of nurosurgeons and ophthalmologists

AIM: To investigate the specialty of transcranial surgery through pterional approach for removal of cranio-orbital tumors, introduce the ophthalmological experiences of entering the orbit to reduce the incidence rate of associated complications of this operation. METHODS: We performed a retrospective analysis of a series of 37 cases involving patients who underwent transcranial surgery through pterional approach for treatment of cranio-orbital tumors in our department in the past 8 years. Pterion approach craniotomy was performed to all patients. After removing tumors in the skull by the neurosurgeon, ophthalmologist removed tumors in orbit. We took measures below to decrease complications, including grounding optic canal through an abrasive drilling when necessary, hanging various extraocular muscles to be exposed for protection, refrigerating by refrigeration heads to remove tumors, at last sewing up orbit septum after surgery. RESULTS: Tumors were removed completely in 32 cases, and incomplete in 5 cases due to extensive invasion into the cavernous sinus or sphenoid sinus. Of all the cases, benign tumors were demonstrated in 28 cases (75.6%, 28/37) and malignant in 9 (24.3%, 9/37). The most common lesion type was meningioma in 11 cases (29.7%, 11/37). Extraocular muscles (EOM) impairment, occurring in 21 cases (56.7%, 21/37), was the most frequent postoperative complication. The most serious consequence was vision loss occurred in 4 cases (10.8%, 4/37). Other complications, such as 11 cases of transient blepharoptosis 29.7% (11/37), 5 cases of mydriasis in 13.5% (5/7); 2 cases of cerebrospinal rhinorrhea in 5.4% (2/37). CONCLUSION: Cranio-orbital tumors can be removed completely using transcranial approach, and the pterional approach offers excellent exposure. Cooperation of interdisciplinary team of neurosurgeons and ophthalmologists conduces to full use of respective professional advantages. The experience of ophthalmic operation technology can decrease occurrence of ocular complications after surgery.

基于改进Deformable DETR模型的多源局部放电识别方法及其应用

基于图像的局部放电识别方法大部分仅对单源局部放电谱图有效,无法识别多源局部放电谱图。为实现对多源局部放电谱图的识别,该文提出一种基于Transformer架构的局部放电Deformable DETR目标检测模型,收集典型单源局部放电和多源局部放电数据,生成局部放电相位角解析和极坐标相位分布解析谱图数据集。在Deformable DETR模型中引入去噪训练任务和贝叶斯优化算法,优化了局部放电目标检测模型;编写局部放电谱图采集和识别程序,并使用优化后的局部放电Deformable DETR模型对单源和多源局部放电谱图进行识别。结果表明:局部放电Deformable DETR模型不仅可有效识别出单源和多源局部放电的类型,而且大幅提升了局部放电类型识别的收敛速度和精度等性能。在对真实绝缘缺陷电动机的局部放电谱图识别中,局部放电Deformable DETR模型的识别准确率达到91%,证明该模型在实际应用中的有效性。

Antimicrobial silver nanoparticle induces organ deformities in the developing Zebrafish (Danio rerio) embryos

Silver Nanoparticles were synthesized by Esche- richia coli using Silver nitrate in the growth me-dium and characterized in X-Ray Diffraction, UV-Vis Spectrophotometer and Scanning Electron Microscope. They exhibited antimicrobial activity against human pathogens except Escherichia Coli. Nanoparticles were impregnated in yarn and ana-lyzed for their inhibition in the broth culture. The Minimal Inhibitory Concentratio was calculated for the human pathogens in Microtitre plate. The toxicity assessment of the nanoparticles in the embry-onic Zebrafish showed many organogensis deformi-ties like cardiac malformations, eye and head edema, tail and trunk flexure were observed in the organ system of the developing embryos for 1 to 5 day post fertilization in different concentrations of Ag Nanoparticles. The Organogenesis disruptive effects were found in 14 - 20 ng/ml of silver nanoparticles but the inhibition was found in 4-10ng/ml for the pathogens in vitro and 10ng/ml in embryos. Nevertheless, in Cardiac assay, the Heart Beat rates were calculated as 42 - 45 for 15 Sec in the concentrations ranging from 10 - 20 ng/ml of Silver nanoparticles. The blood flows, rhythmicity, contractility of heart beat rates were observed normal. The Mean value of blood Cell counting did not showed any notable effects in the Nanoparticle treated Zebrafish embryos and control. The LC50 value for the Biosynthesized nanoparticle was at 22 ng/ml in all the developmental stages of the em-bryos. Our results shows silver nanoparticles dis-rupts the normal organogenesis during development and further detailed studies are needed to prove silver nanopartcles are an antimicrobial agent for use in humans.

Deformities in silver pomfret Pampus argenteus caught from Kuwait waters

During sampling for spawning stock of the silver pomfret,Pampus argenteus in Kuwait waters,a few seriously deformed individuals were captured.These individuals had been attacked and wounded,but had healed and survived.The fish body deformities are believed to be caused by predation attempts on silver pomfret by predators such as sharks,groupers,and croakers.

Three-Dimensional Computed Tomography Assessment and Planning for Severe Lower Limb Deformities: A Case Report of Bilateral Fibular Hemimelia

To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.

BMPR-IB gene disruption causes severe limb deformities in pigs

In an attempt to generate g.A746G substitution in the BMPR-IB gene,we unexpectedly obtained BMPR-IB homozygous knockout piglets(BMPR-IB^(-/-))and heterogeneous knockout piglets with one copy of the A746G mutation(BMPR-IB-/746G)via CRISPR/Cas9 editing.Polymerase chain reaction(PCR)and sequencing revealed complex genomic rearrangements in the target region.All BMPR-IBdisrupted piglets showed an inability to stand and walk normally.Both BMPR-IB^(-/-)and BMPR-IB-/746G piglets exhibited severe skeletal dysplasia characterized by distorted and truncated forearms(ulna,radius)and disordered carpal,metacarpal,and phalangeal bones in the forelimbs.The piglets displayed more severe deformities in the hindlimbs by visual inspection,including fibular hemimelia,enlarged tarsal bone,and disordered toe joint bones.Limb deformities were more profound in BMPR-IB^(-/-)piglets than in the BMPR-IB-/746G piglets.Proteomic analysis identified 139 differentially expressed proteins(DEPs)in the hindlimb fibula of BMPR-IB-/746G piglets compared to the wild-type(WT)controls.Most DEPs are involved in skeletal or embryonic development and/or the TGF-βpathway and tumor progression.Gene Ontology(GO)and protein domain enrichment analysis suggested alterations in these processes.Of the top 50 DEPs,a large proportion,e.g.,C1QA,MYO1H,SRSF1,P3H1,GJA1,TCOF1,RBM10,SPP2,MMP13,and PHAX,were significantly associated with skeletal development.Our study provides novel findings on the role of BMPR-IB in mammalian limb development.

Surgical treatment of femoral deformities in polyostotic fibrous dysplasia and McCune-Albright syndrome:A literature review

BACKGROUND Surgical correction of femoral deformities in polyostotic fibrous dysplasia(PFD)or McCune-Albright syndrome(MAS),such as coxa vara or shepherd’s crook deformity,is a challenge.AIM To evaluate the treatment of patients with femoral deformities caused by PDF or MAS treated by osteotomies and stabilized with different methods,by analyzing the most relevant studies on the topic.METHODS A literature search was performed in Medline database(PubMed).Articles were screened for patients affected by PFD or MAS surgically managed by osteotomies and stabilized with different methods.RESULTS The initial search produced 184 studies,with 15 fulfilling the eligibility criteria of our study.Selected articles(1987-2019)included 111 patients overall(136 femurs).CONCLUSION Based on our results,the preferred method to stabilize corrective osteotomies is intramedullary nailing with neck cross pinning.When the deformity is limited to the proximal part of the femur,a screw or blade plate may be used,although there is a high risk of fracture below the plate.When the femur is entirely involved,a two-stage procedure may be considered.

基于改进Deformable DETR的无人机视频流车辆目标检测算法

针对无人机视频流检测中小目标数量多、因图像传输质量较低而导致的上下文语义信息不充分、传统算法融合特征推理速度慢、数据集类别样本不均衡导致的训练效果差等问题,提出一种基于改进Deformable DETR的无人机视频流车辆目标检测算法。在模型结构方面,该算法设计了跨尺度特征融合模块以增大感受野,提升小目标检测能力,并采用针对object_query的挤压-激励模块提升关键目标的响应值,减少重要目标的漏检与错检率;在数据处理方面,使用了在线困难样本挖掘技术,改善数据集中类别样本分布不均的问题。在UAVDT数据集上进行了实验,实验结果表明,改进后的算法相较于基线算法在平均检测精度上提升了1.5%,在小目标检测精度上提升了0.8%,并在保持参数量较少增长的情况下,维持了原有的检测速度。

Spinal deformities in a wild line of Poecilia wingei bred in captivity:report of cases and review of the literature

Objective:To describe the occurrence of various spinal deformations in a captive-bred wild line of Poecilia wingei(P.wingei).Methods:Fish belonging to a wild line of P.wingei caught from Laguna de Los Patos,Venezuela,were bred in an aquarium home-breeding system during a period of three years(2006-2009).The spinal curvature was observed to study spinal deformities in P.wingei.Results:Out of a total of 600 fish,22 showed different types of deformities(scoliosis,lordosis,kyphosis),with a higher incidence in females.Growth,swimming and breeding of deformed fish were generally normal.Conclusions:Possible causes for spinal curvature in fish are discussed on the basis of the current literature.While it is not possible to determine the exact cause(s)of spinal deformities observed in the present study,traumatic injuries,nutritional imbalances,genetic defects or a combination of these factors can be supposed to be involved in the pathogenesis of such lesions.

Application of Cephalometric Analysis To Surgical Treatment of Dentofacial Deformities

In view of orthognathic surgery,on the basis of the ccphalometric data of the youths innorth-west China,the most common 29 parameters were chosen,including angles,linear measureand ratio.For analysis,they were divided into four groups:general profile feature,maxilla andorbital-zygomatic regio,mandible and chin.This kind of analysis can be usecd for clinicaldiagnosis and for detemining the nature,position and degree of the dcformities.It is espceially effec-five in the designing of operation and prediction of the result of the surgery.

Deformation monitoring of long-span railway bridges based on SBAS-InSAR technology

The deformation monitoring of long-span railway bridges is significant to ensure the safety of human life and property.The interferometric synthetic aperture radar(In SAR)technology has the advantage of high accuracy in bridge deformation monitoring.This study monitored the deformation of the Ganjiang Super Bridge based on the small baseline subsets(SBAS)In SAR technology and Sentinel-1A data.We analyzed the deformation results combined with bridge structure,temperature,and riverbed sediment scouring.The results are as follows:(1)The Ganjiang Super Bridge area is stable overall,with deformation rates ranging from-15.6 mm/yr to 10.7 mm/yr(2)The settlement of the Ganjiang Super Bridge deck gradually increases from the bridge tower toward the main span,which conforms to the typical deformation pattern of a cable-stayed bridge.(3)The sediment scouring from the riverbed cause the serious settlement on the bridge’s east side compared with that on the west side.(4)The bridge deformation negatively correlates with temperature,with a faster settlement at a higher temperature and a slow rebound trend at a lower temperature.The study findings can provide scientific data support for the health monitoring of long-span railway bridges.

Application of GNSS-PPP on Dynamic Deformation Monitoring of Offshore Platforms

The real-time dynamic deformation monitoring of offshore platforms under environmental excitation is crucial to their safe operation.Although Global Navigation Satellite System-Precise Point Positioning(GNSS-PPP)has been considered for this purpose,its monitoring accuracy is relatively low.Moreover,the influence of background noise on the dynamic monitoring accuracy of GNSS-PPP remains unclear.Hence,it is imperative to further validate the feasibility of GNSS-PPP for deformation monitoring of offshore platforms.To address these concerns,vibration table tests with different amplitudes and frequencies are conducted.The results demonstrate that GNSS-PPP can effectively monitor horizontal vibration displacement as low as±30 mm,which is consistent with GNSS-RTK.Furthermore,the spectral characteristic of background noise in GNSS-PPP is similar to that of GNSS-RTK(Real Time Kinematic).Building on this observation,an improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)has been proposed to de-noise the data and enhance the dynamic monitoring accuracy of GNSS-PPP.Field monitoring application research is also undertaken,successfully extracting and analyzing the dynamic deformation of an offshore platform structure under environmental excitation using GNSS-PPP monitoring in conjunction with improved CEEMDAN de-noising.By comparing the de-noised dynamic deformation trajectories of the offshore platform during different periods,it is observed that the platform exhibits reversible alternating vibration responses under environmental excitation,with more pronounced displacement deformation in the direction of load action.The research results confirm the feasibility and potential of GNSS-PPP for dynamic deformation monitoring of offshore platforms.

Violent collisions can reveal hexadecapole deformation of nuclei

A new observable in heavy ion collision experiments was identified to be sensitive to the hexadecapole deformation of the colliding nuclei.Such deformation is difficult to measure in traditional nuclear electric transition measurements,as it is often overwhelmed by the nuclear quadrupole deformation.This opens the door to gain new insight into nuclear structure with experiments that were designed to study hot and dense nuclear matter.