A molecular dynamics study on mechanical performance and deformation mechanisms in nanotwinned NiCo-based alloys with nano-precipitates under high temperatures

Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures,as well as the interactions between the dislocations and nano-precipitates within the nanotwins.The simulation results demonstrate that both the yield stress and flow stress in the nanotwinned NiCo-based alloys with nano-precipitates decrease as the temperature rises,because the higher temperatures lead to the generation of more defects during yielding and lower dislocation density during plastic deformation.Moreover,the coherent L12 phase exhibits excellent thermal stability,which enables the hinderance of dislocation motion at elevated temperatures via the wrapping and cutting mechanisms of dislocations.The synergistic effect of nanotwins and nano-precipitates results in more significant strengthening behavior in the nanotwinned NiCo-based alloys under high temperatures.In addition,the high-temperature mechanical behavior of nanotwinned NiCo-based alloys with nano-precipitates is sensitive to the size and volume fraction of the microstructures.These findings could be helpful for the design of nanotwins and nano-precipitates to improve the high-temperature mechanical properties of NiCo-based alloys.

Train wheel-rail force collaborative calibration based on GNN-LSTM

Accurate wheel-rail force data serves as the cornerstone for analyzing the wheel-rail relationship.However,achieving continuous and precise measurement of this force remains a significant challenge in the field.This article introduces a calibration algorithm for the wheel-rail force that leverages graph neural networks and long short-term memory networks.Initially,a comprehensive wheel-rail force detection system for trains was constructed,encompassing two key components:an instrumented wheelset and a ground wheel-rail force measuring system.Subsequently,utilizing this system,two distinct datasets were acquired from the track inspection vehicle:instrumented wheelset data and ground wheel-rail force data,a feedforward neural network was employed to calibrate the instrumented wheelset data,referencing the ground wheel-rail force data.Furthermore,ground wheel-rail force data for the locomotive was obtained for the corresponding road section.This data was then integrated with the calibrated instrumented wheelset data from the track inspection vehicle.Leveraging the GNN-LSTM network,the article establishes a mapping relationship model between the wheel-rail force of the track inspection vehicle and the locomotive wheel-rail force.This model facilitates continuous measurement of locomotive wheel-rail forces across three typical scenarios:straight sections,long and steep downhill sections,and small curve radius sections.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypl stage after neoadjuvant chemo-radiotherapy versus de novo stage pl cohort:A propensity score-matched analysis

Objective：Prognosis of patients with locally advanced rectal cancer（LARC）but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy（CRT）has been shown to be favorable.This study aims to determine whether the long-term outcome of yp T1–2N0 cases can be comparable to that of p T1–2N0 cohort that received definitive surgery for early disease.Method：From January 2008 to December 2013,449 consecutive patients with rectal cancer were treated and their outcome maintained in a database.Patients with LARC underwent total mesorectal excision（TME）surgery at4–8 weeks after completion of CRT,and those achieving stage yp I were identified as a group.As a comparison,stage p I group pertains to patients whose initially limited disease was not upstaged after TME surgery alone.After propensity score matching（PSM）,comparisons of local regional control（LC）,distant metastasis-free survival（DMFS）,disease-free survival（DFS）and overall survival（OS）were performed using Kaplan-Meier analysis and log-rank test between yp I and p I groups.Down-staging depth score（DDS）,a novel method of evaluating CRT response,was used for subset analysis.Results：Of the 449 patients,168 matched cases were generated for analysis.Five-year LC,DMFS,DFS and OS for stage p I vs.yp I groups were 96.7%vs.96.4%（P=0.796）,92.7%vs.73.6%（P=0.025）,91.2%vs.73.6%（P=0.080）and 93.1%vs.72.3%（P=0.040）,respectively.In the DDS-favorable subset of the yp I group,LC,DMFS,DFS and OS resulted in no significant differences in comparison with the p I group（P=0.384,0.368,0.277 and0.458,respectively）.Conclusions：LC was comparable in both groups;however,distant metastasis developed more frequently in down-staged LARC than de novo early stage cases,reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response.DDS can be an indicator to identify a subset of the yp I group whose longterm oncologic outcomes are as good as those of stage p I cohort.

Molecular dynamics study on the dependence of thermal conductivity on size and strain in GaN nanofilms

The thermal conductivity of GaN nanofilm is simulated by using the molecular dynamics(MD)method to explore the influence of the nanofilm thickness and the pre-strain field under different temperatures.It is demonstrated that the thermal conductivity of GaN nanofilm increases with the increase of nanofilm thickness,while decreases with the increase of temperature.Meanwhile,the thermal conductivity of strained GaN nanofilms is weakened with increasing the tensile strain.The film thickness and environment temperature can affect the strain effect on the thermal conductivity of GaN nanofilms.In addition,the analysis of phonon properties of GaN nanofilm shows that the phonon dispersion and density of states of GaN nanofilms can be significantly modified by the film thickness and strain.The results in this work can provide the theoretical supports for regulating the thermal properties of GaN nanofilm through tailoring the geometric size and strain engineering.

Effects of Auxin at Different Concentrations on the Growth,Root Morphology and Cadmium Uptake of Maize(Zea mays L.)

Indoleacetic acid(IAA)is an important regulator that plays a crucial role in plant growth and responses to abiotic stresses.In the present study,a sand cultivation experiment was carried out to investigate the effects of IAA at different concentrations(0,0.01,0.1,0.5,1,and 2.5 mmol/L)on maize growth,root morphology,mineral elements(Ca,Mg)and Cd uptake under 20 mg/kg Cd stress.The results showed that 0.01 mmol/L is the optimal IAA concentration for enhancing the Cd tolerance of maize.Compared with the control treatment,0.01 mmol/L IAA promoted maize growth,with significant increases in the height,shoot and root biomass by 34.6%,25.0%and 16.3%;altered the root morphology,with increases in root length,root tip number,and root tip density by 8.9%,31.4%and 20.7%,respectively;and enhanced the mineral element uptake of maize,resulting in signifi-cant increases in the Ca content in shoots and roots by 640.6%and 1036.4%and in the Mg content in shoots by 205.8%,respectively.In addition,0.01 mmol/L IAA decreased the Cd content and uptake in the shoots by 51.9%and 39.6%,respectively.Furthermore,the Cd content and uptake exhibited a significant negative correlation with Ca content in roots and a significantly positive correlation with root morphology,and the Cd content in shoots was significantly and negatively correlated with root tip number.Thus,0.01 mmol/L IAA was effective in enhancing the Cd tolerance and plant growth of maize.

Research on Bolt Support Technology in Soft Coal Seam Roadway

In order to solve the problem of surrounding rock control in soft coal seam roadway, taking the centralized return airway of No. 2 coal seam in Liangdu Coal Industry as the research background, the mechanical conditions of roadway surrounding rock were analyzed by means of field investigation, rock mechanics experiment and numerical simulation. The design principles of roadway support in soft coal seam were put forward: high strength anchor cable support, high preload support and high stiffness support. The bearing capacity of surrounding rock was strengthened by anchor cable support, and the deformation and failure of surrounding rock were effectively controlled. Through the numerical simulation method, the deformation and plastic failure range of roadwaysunder different support schemes are compared and analyzed. The support scheme of centralized transportation roadway is studied and determined, and the field test is carried out, which effectively controls the deformation of surrounding rock of roadway in weak coal seam.

Clinical Efficacy of Needle Warming through Moxibustion Combined with Tuina on Retrogressive Knee Osteoarthritis

[Objectives] To study the clinical efficacy of needle warming through moxibustion combined with Tuina on retrogressive knee osteoarthritis, and to explore the effective treatment with traditional Chinese medicine characteristics.[Methods] 60 patients with retrogressive knee osteoarthritis were randomly divided into control group ( n =30) and observation group ( n =30). The control group was treated with Tuina, while the observation group was treated with needle warming through moxibustion combined with Tuina. The clinical cure rate, pain score and knee symptom score were compared and analyzed.[Results] The clinical cure rate was 96.70% in the observation group and 73.30% in the control group, and the difference was statistically significant ( P <0.05). After one course of treatment, the VAS score and knee Lequesne score of the two groups were decreased ( P <0.05), and the decrease degree of the observation group was better than that of the control group ( P <0.05). The joint rest pain score, joint motion pain score, tenderness score, swelling score, morning stiffness score and walking ability score were higher than those in the treatment group ( P <0.05).[Conclusions] Needle warming through moxibustion combined with Tuina manipulation can significantly alleviate knee degenerative disease, eliminate inflammation, reduce edema, ease pain and improve the quality of life of patients.

Power system transient stability assessment based on the multiple paralleled convolutional neural network and gated recurrent unit

In order to accurately evaluate power system stability in a timely manner after faults,and further improve the feature extraction ability of the model,this paper presents an improved transient stability assessment(TSA)method of CNN+GRU.This comprises a convolutional neural network(CNN)and gated recurrent unit(GRU).CNN has the feature extraction capability for a micro short-term time sequence,while GRU can extract characteristics contained in a macro long-term time sequence.The two are integrated to comprehensively extract the high-order features that are contained in a transient process.To overcome the difficulty of sample misclassification,a multiple parallel(MP)CNN+GRU,with multiple CNN+GRU connected in parallel,is created.Additionally,an improved focal loss(FL)func-tion which can implement self-adaptive adjustment according to the neural network training is introduced to guide model training.Finally,the proposed methods are verified on the IEEE 39 and 145-bus systems.The simulation results indicate that the proposed methods have better TSA performance than other existing methods.

Higher-order valley vortices enabled by synchronized rotation in a photonic crystal

Synchronized rotation of unit cells in a periodic structure provides a novel design perspective for manipulation of band topology.We then design a two-dimensional version of higher-order topological insulator(HOTI)by such rotation in a triangular photonic lattice with C_(3) symmetry.This HOTI supports the hallmark zero-dimensional corner states and,simultaneously,the one-dimensional edge states.We also find that our photonic corner states carry chiral orbital angular momenta locked by valleys,whose wave functions are featured by the phase vortex(singularity)positioned at the maximal Wyckoff points.Moreover,when excited by a fired source with various frequencies,the valley topological states of both one-dimensional edges and zero-dimensional corners emerge simultaneously.Extendable to higher or synthetic dimensions,our paper provides access to a chiral vortex platform for HOTI realizations in the terahertz photonic system.

Design and realization of indoor VLC-Wi-Fi hybrid network

Indoor wireless communication networking has received significant attention along with the growth of indoor data traffic.VLC(Visible Light Communication)as a novel wireless communication technology with the advantages of a high data rate,license-free spectrum and safety provides a practical solution for the indoor high-speed transmission of large data traffic.However,limited coverage is an inherent feature of VLC.In this paper,we propose a novel hybrid VLC-Wi-Fi system that integrates multiple links to achieve an indoor high-speed wide-coverage network combined with multiple access,a multi-path transmission control protocol,mobility management and cell handover.Furthermore,we develop a hybrid network experiment platform,the experimental results of which show that the hybrid VLC-Wi-Fi network outperforms both single VLC and Wi-Fi networks with better coverage and greater network capacity.

3D reconstruction of human head based on consumer RGB-D sensors

Three-dimensional(3D)reconstruction of a human head with high precision has promising applications in scientific research,product design and other fields.However,it still faces resistance from two factors.One is inaccurate registration caused by symmetrical distribution of head feature points,and the other is economic burden due to highaccuracy sensors.Research on 3D reconstruction with portable consumer RGB-D sensors such as the Microsoft Kinect has been highlighted in recent years.Based on our multi-Kinect system,a precise and low-cost three-dimensional modeling method and its system implementation are introduced in this paper.A registration method for multisource point clouds is provided,which can reduce the fusion differences and reconstruct the head model accurately.In addition,a template-based texture generation algorithm is presented to generate a fine texture.The comparison and analysis of our experiments show that our method can reconstruct a head model in an acceptable time with less memory and better effect.