At-rest lateral earth pressure of compacted expansive soils:Experimental investigations and prediction approach

This paper presents experimental studies on a compacted expansive soil,from Nanyang,China for investigating the at-rest lateral earth pressureσL of expansive soils.The key studies include(i)relationships between theσL and the vertical stressσV during soaking and consolidation,(ii)the influences of initial dry densityρd0 and moisture content w 0 on the vertical and lateral swelling pressures at no swelling strain(i.e.σV0 andσL0),and(iii)evolution of theσL during five long-term wetting-drying cycles.Experimental results demonstrated that the post-soakingσL-σV relationships are piecewise linear and their slopes in the passive state(σL>σV)and active state(σL<σV)are similar to that of the consolidationσL-σV relationships in the normal-and over-consolidated states,respectively.The soakingσL-σV relationships converge to the consolidationσL-σV relationships at a thresholdσV where the interparticle swelling is restrained.TheσL0 andσV0 increase monotonically withρd0;however,they show increasing-then-decreasing trends with the w 0.The extent of compaction-induced swelling anisotropy,which is evaluated byσL0/σV0,reduces with an increase in the compaction energy and molding water content.TheσL reduces over moisture cycles and the stress relaxation in theσL during soaking is observed.An approach was developed to predict the at-rest soakingσL-σV relationships,which requires conventional consolidation and shear strength properties and one measurement of theσL-σV relationships during soaking.The proposed approach was validated using the results of three different expansive soils available in the literature.

Mass transfer enhancement and hydrodynamic performance with wire mesh coupling solid particles in bubble column reactor

It is of vital significance to investigate mass transfer enhancements for chemical engineering processes.This work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble column.Particle image velocimetry(PIV)technology was employed to analyze the flow field and bubble motion behavior,and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient(kLa).The effect of embedding wire mesh,adding solid particles,and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and compared.The results show that the gas-liquid interface area increases by 33%-72%when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow,which is superior to the other two strengthening methods.Compared with the system without reinforcement,kLa in the bubble column increased by 0.5-1.8 times with wire mesh coupling solid particles method,which is higher than the sum of kLa increases with inserting wire mesh and adding particles,and the coupling reinforcement mechanism for affecting gas-liquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer.

MiR-150-5p inhibits cell proliferation and metastasis by targeting FTO in osteosarcoma

Background:Osteosarcoma(OS),recognized as the predominant malignant tumor originating from bones,necessitates an in-depth comprehension of its intrinsic mechanisms to pinpoint novel therapeutic targets and enhance treatment methodologies.The role of fat mass and obesity-associated(FTO)in OS,particularly its correlation with malignant traits,and the fundamental mechanism,remains to be elucidated.Materials and Methods:1.The FTO expression and survival rate in tumors were analyzed.2.FTO in OS cell lines was quantified utilizing western blot and PCR.3.FTO was upregulated and downregulated separately in MG63.4.The impact of FTO on the proliferation and migration of OS cells was evaluated using CCK-8,colony formation,wound healing,and Transwell assays.5.The expression of miR-150-5p in OS cells-derived exosomes was identified.6.The binding of miR-150-5p to FTO was predicted by TargetScan and confirmed by luciferase reporter assay.7.The impact of exosome miR-150-5p on the proliferation and migration of OS cells was investigated.Results:The expression of FTO was higher in OS tissues compared to normal tissues correlating with a worse survival rate.Furthermore,the downregulation of FTO significantly impeded the growth and metastasis of OS cells.Additionally,miR-150-5p,which was downregulated in both OS cells and their derived exosomes,was found to bind to the 3′-UTR of FTO through dual luciferase experiments.Exosomal miR-150-5p was found to decrease the expression of FTO and inhibit cell viability.Conclusions:We identified elevated levels of FTO in OS,which may be attributed to insufficient miR-150-5p levels in both the cells and exosomes.It suggests that the dysregulation of miR-150-5p and its interaction with FTO could potentially promote the development of OS.

Parametric investigation of railway fastenings into the formation and mitigation of short pitch corrugation

Short pitch corrugation has been a problem for railways worldwide over one century.In this paper,a parametric investigation of fastenings is conducted to understand the corrugation formation mechanism and gain insights into corrugation mitigation.A three-dimensional finite element vehicle-track dynamic interaction model is employed,which considers the coupling between the structural dynamics and the contact mechanics,while the damage mechanism is assumed to be differential wear.Various fastening models with different configurations,boundary conditions,and parameters of stiffness and damping are built up and analysed.These models may represent different service stages of fastenings in the field.Besides,the effect of train speeds on corrugation features is studied.The results indicate:(1)Fastening parameters and modelling play an important role in corrugation formation.(2)The fastening longitudinal constraint to the rail is the major factor that determines the corrugation formation.The fastening vertical and lateral constraints influence corrugation features in terms of spatial distribution and wavelength components.(3)The strengthening of fastening constraints in the longitudinal dimension helps to mitigate corrugation.Meanwhile,the inner fastening constraint in the lateral direction is necessary for corrugation alleviation.(4)The increase in fastening longitudinal stiffness and damping can reduce the vibration amplitudes of longitudinal compression modes and thus reduce the track corrugation propensity.The simulation in this work can well explain the field corrugation in terms of the occurrence possibility and major wavelength components.It can also explain the field data with respect to the small variation between the corrugation wavelength and train speed,which is caused by frequency selection and jump between rail longitudinal compression modes.

Clinical study on improving the diagnostic accuracy of adult elbow joint cartilage injury by multisequence magnetic resonance imaging

BACKGROUND Due to frequent and high-risk sports activities,the elbow joint is susceptible to injury,especially to cartilage tissue,which can cause pain,limited movement and even loss of joint function.AIM To evaluate magnetic resonance imaging(MRI)multisequence imaging for improving the diagnostic accuracy of adult elbow cartilage injury.METHODS A total of 60 patients diagnosed with elbow cartilage injury in our hospital from January 2020 to December 2021 were enrolled in this retrospective study.We analyzed the accuracy of conventional MRI sequences(T1-weighted imaging,T2-weighted imaging,proton density weighted imaging,and T2 star weighted image)and Three-Dimensional Coronary Imaging by Spiral Scanning(3D-CISS)in the diagnosis of elbow cartilage injury.Arthroscopy was used as the gold standard to evaluate the diagnostic effect of single and combination sequences in different injury degrees and the consistency with arthroscopy.RESULTS The diagnostic accuracy of 3D-CISS sequence was 89.34%±4.98%,the sensitivity was 90%,and the specificity was 88.33%,which showed the best performance among all sequences(P<0.05).The combined application of the whole sequence had the highest accuracy in all sequence combinations,the accuracy of mild injury was 91.30%,the accuracy of moderate injury was 96.15%,and the accuracy of severe injury was 93.33%(P<0.05).Compared with arthroscopy,the combination of all MRI sequences had the highest consistency of 91.67%,and the kappa value reached 0.890(P<0.001).CONCLUSION Combination of 3D-CISS and each sequence had significant advantages in improving MRI diagnostic accuracy of elbow cartilage injuries in adults.Multisequence MRI is recommended to ensure the best diagnosis and treatment.

Effects of Functional Organic Materials on Morphological Indexes,Quality and Yield of Watermelon

[Objectives]This study was conducted to explore suitable organic compound application models for watermelon growth.[Methods]With watermelon hybrid material"M22×P18"as the test material,the effects of four functional organic materials,namely garlic straw treatment(T_(1)),onion straw treatment(T_(2)),garlic straw+sheep manure treatment(T_(3))and onion straw+chicken manure treatment(T_(4)),on the morphological indexes,yield and quality of watermelon were investigated.[Results]Different functional organic materials had different effects on morphological indexes,yield and quality of watermelon.The morphological indexes,nutritional quality indexes and yield of watermelon treated with garlic straw and sheep manure compound(T_(3))and onion straw and chicken manure compound(T_(4))were significantly higher than those treated simply with garlic straw(T_(1))and onion straw(T_(2)),and T_(3)performed relatively better.Compared with treatment T_(2),T_(3)showed a stem diameter,vine length and leaf number increasing by 43.05%,46.69%and 40.77%respectively,central sugar and side sugar contents increasing by 11.72%and 21.90%respectively,and a yield increasing by 42.91%,with significant differences from T_(2).[Conclusions]This study provides technical support for high-quality and high-yielding cultivation of watermelon.

新工科背景下“大学物理”课程考核方式改革实践

针对考核方式存在的问题,根据新工科对人才培养的新要求,提出了“大学物理”课程考核方式改革方案:增加考核次数、创新过程考核方法、增设综合能力考核,以此通过增强过程考核来加强对学生综合能力的培养。通过对考核方式进行效果评估和对比改革前后的教学效果可以看出,改革后的考核方式较好地提升了课程教学质量,并形成了良好的教学反馈机制。

Multi-source coordinated stochastic restoration for SOP in distribution networks with a two-stage algorithm

After suffering from a grid blackout, distributed energy resources(DERs), such as local renewable energy and controllable distributed generators and energy storage can be used to restore loads enhancing the system’s resilience. In this study, a multi-source coordinated load restoration strategy was investigated for a distribution network with soft open points(SOPs). Here, the flexible regulation ability of the SOPs is fully utilized to improve the load restoration level while mitigating voltage deviations. Owing to the uncertainty, a scenario-based stochastic optimization approach was employed,and the load restoration problem was formulated as a mixed-integer nonlinear programming model. A computationally efficient solution algorithm was developed for the model using convex relaxation and linearization methods. The algorithm is organized into a two-stage structure, in which the energy storage system is dispatched in the first stage by solving a relaxed convex problem. In the second stage, an integer programming problem is calculated to acquire the outputs of both SOPs and power resources. A numerical test was conducted on both IEEE 33-bus and IEEE 123-bus systems to validate the effectiveness of the proposed strategy.

Variational quantum simulation of thermal statistical states on a superconducting quantum processer

Quantum computers promise to solve finite-temperature properties of quantum many-body systems,which is generally challenging for classical computers due to high computational complexities.Here,we report experimental preparations of Gibbs states and excited states of Heisenberg X X and X X Z models by using a 5-qubit programmable superconducting processor.In the experiments,we apply a hybrid quantum–classical algorithm to generate finite temperature states with classical probability models and variational quantum circuits.We reveal that the Hamiltonians can be fully diagonalized with optimized quantum circuits,which enable us to prepare excited states at arbitrary energy density.We demonstrate that the approach has a self-verifying feature and can estimate fundamental thermal observables with a small statistical error.Based on numerical results,we further show that the time complexity of our approach scales polynomially in the number of qubits,revealing its potential in solving large-scale problems.

Synergy mechanism of defect engineering in MoS_(2)/FeS_(2)/C heterostructure for high-performance sodium-ion battery

MoS_(2) is a promising anode material in sodium-ion battery technologies for possessing high theoretical capacity.However,the sluggish Na^(+) diffusion kinetics and low electronic conductivity hinder the promises.Herein,a unique MoS_(2)/FeS_(2)/C heterojunction with abundant defects and hollow structure(MFCHHS)was constructed.The synergy of defect engineering in MoS_(2),FeS_(2),and the carbon layer of MFCHHS with a larger specific surface area provides multiple storage sites of Na^(+)corresponding to the surface-controlled process.The MoS_(2)/FeS_(2)/C heterostructure and rich defects in MoS_(2) and carbon layer lower the Na^(+) diffusion energy barrier.Additionally,the construction of MoS_(2)/FeS_(2) heterojunction promotes electron transfer at the interface,accompanying with excellent conductivity of the carbon layer to facilitate reversible electrochemical reactions.The abundant defects and mismatches at the interface of MoS_(2)/FeS_(2) and MoS_(2)/C heterojunctions could relieve lattice stress and volume change sequentially.As a result,the MFCHHS anode exhibits the high capacity of 613.1 mA h g^(-1)at 0.5 A g^(-1) and 306.1 mA h g^(-1) at 20 A g^(-1).The capacity retention of 85.0%after 1400 cycles at 5.0 A g^(-1) is achieved.The density functional theory(DFT)calculation and in situ transmission electron microscope(TEM),Raman,ex-situ X-ray photon spectroscopy(XPS)studies confirm the low volume change during intercalation/deintercalation process and the efficient Na^(+)storage in the layered structure of MoS_(2) and carbon layer,as well as the defects and heterostructures in MFCHHS.We believe this work could provide an inspiration for constructing heterojunction with abundant defects to foster fast electron and Na^(+) diffusion kinetics,resulting in excellent rate capability and cycling stability.

Loss of behavioral stress response in blind cavefish reduces energy expenditure

The stress response is essential for animal self-defense and survival. However, species may exhibit stress response variation depending on their specific environmental and selection pressures. Blind cavefish dwell in cave environments, which differ markedly in stressors and resource availability compared to surface aquatic environments. However, whether blind cavefish exhibit differences in stress response as an adaptation to their cave environments remains unclear. Here, we investigated differences in stress response in six closely related Triplophysa species, including three blind cavefish (T. longibarbata, T. jiarongensis, and T. rosa) and three normal-sighted river fish (T. nasobarbatula, T. dongsaiensis, and T. bleekeri). Results showed that blind cavefish exhibited a range of distinct behavioral responses compared to sighted river fish, including greater levels of activity, shorter duration of freezing, absence of erratic movements or thrashing behavior, and opposite behavioral trends over time. Furthermore, the cavefish species demonstrated attenuated increases in metabolic rate in response to stressors related to novel environments. Cave-dwelling T. rosa also exhibited lower basal hypothalamic-pituitary-inter-renal (HPI) axis-related gene expression levels and stress hormone concentrations compared to river-dwelling T. bleekeri. These results suggest that blind cavefish may have lost their behavioral stress response, potentially mediated by a reduction in basal activity of the HPI axis, thus enabling the conservation of energy by reducing unnecessary expenditure in energy-limited caves.

In-situ 3D contour measurement for laser powder bed fusion based on phase guidance

In-situ layerwise imaging measurement of laser powder bed fusion(LPBF)provides a wealth of forming and defect data which enables monitoring of components quality and powder bed homogeneity.Using high-resolution camera layerwise imaging and image processing algorithms to monitor fusion area and powder bed geometric defects has been studied by many researchers,which successfully monitored the contours of components and evaluated their accuracy.However,research for the methods of in-situ 3D contour measurement or component edge warping identification is rare.In this study,a 3D contour mea-surement method combining gray intensity and phase difference is proposed,and its accuracy is verified by designed experiments.The results show that the high-precision of the 3D contours can be achieved by the constructed energy minimization function.This method can detect the deviations of common ge-ometric features as well as warpage at LPBF component edges,and provides fundamental data for in-situ quality monitoring tools.

Preparation and Performance of n-Dodecane Microencapsulated Phase Change Cold Storage Materials

Cold chain transportation is currently a hot research topic.Since the traditional refrigeration methods lead to the consumption of large amounts of energy,the search for new energy storage materials is a major trend.In the present contribution,n-dodecane/PMMA microencapsulated phase change materials were prepared by suspension polymerization for ice-temperature cold chain transportation and their preparation parameters were explored using the encapsulation ratio as optimization indicator.The results show that the n-dodecane-containing microcapsules have a maximum encapsulation ratio of 93.2%when using a core-to-wall ratio of 3:1,5%of emulsifier,30%of crosslinker,and 2000 rpm of emulsification speed.The phase transition temperature and enthalpy are-2℃and 195.9 kJ/kg,respectively.The microcapsules prepared with the optimized process parameters have good microscopic morphology,high energy storage efficiency,uniform particle size and good thermal stability,making them ideal materials for cold chain transportation.

RT-YOLO:A Residual Feature Fusion Triple Attention Network for Aerial Image Target Detection

In recent years,target detection of aerial images of unmannedaerial vehicle(UAV)has become one of the hottest topics.However,targetdetection of UAV aerial images often presents false detection and misseddetection.We proposed a modified you only look once(YOLO)model toimprove the problems arising in object detection in UAV aerial images:(1)A new residual structure is designed to improve the ability to extract featuresby enhancing the fusion of the inner features of the single layer.At the sametime,triplet attention module is added to strengthen the connection betweenspace and channel and better retain important feature information.(2)Thefeature information is enriched by improving the multi-scale feature pyramidstructure and strengthening the feature fusion at different scales.(3)A newloss function is created and the diagonal penalty term of the anchor frame isintroduced to improve the speed of training and the accuracy of reasoning.The proposed model is called residual feature fusion triple attention YOLO(RT-YOLO).Experiments showed that the mean average precision(mAP)ofRT-YOLO is increased from 57.2%to 60.8%on the vehicle detection in aerialimage(VEDAI)dataset,and the mAP is also increased by 1.7%on the remotesensing object detection(RSOD)dataset.The results show that theRT-YOLOoutperforms other mainstream models in UAV aerial image object detection.

Letter to editor‘Non-invasive model for predicting high-risk esophageal varices based on liver and spleen stiffness’

predicting high-risk esophageal varices based on liver and spleen stiffness".Acute bleeding caused by esophageal varices is a life-threatening complication in patients with liver cirrhosis.Due to the discomfort,contraindications,and associated complications of upper gastrointestinal endoscopy screening,it is crucial to identify an imaging-based non-invasive model for predicting high-risk esophageal varices in patients with cirrhosis.

Cofitness network connectivity determines a fuzzy essential zone in open bacterial pangenome

Most in silico evolutionary studies commonly assumed that core genes are essential for cellular function,while accessory genes are dispensable,particularly in nutrient-rich environments.However,this assumption is seldom tested genetically within the pangenome context.In this study,we conducted a robust pangenomic Tn-seq analysis of fitness genes in a nutrient-rich medium for Sinorhizobium strains with a canonical open pangenome.To evaluate the robustness of fitness category assignment,Tn-seq data for three independent mutant libraries per strain were analyzed by three methods,which indicates that the Hidden Markov Model(HMM)-based method is most robust to variations between mutant libraries and not sensitive to data size,outperforming the Bayesian and Monte Carlo simulation-based methods.Consequently,the HMM method was used to classify the fitness category.Fitness genes,categorized as essential(ES),advantage(GA),and disadvantage(GD)genes for growth,are enriched in core genes,while nonessential genes(NE)are over-represented in accessory genes.Accessory ES/GA genes showed a lower fitness effect than core ES/GA genes.Connectivity degrees in the cofitness network decrease in the order of ES,GD,and GA/NE.In addition to accessory genes,1599 out of 3284 core genes display differential essentiality across test strains.Within the pangenome core,both shared quasi-essential(ES and GA)and strain-dependent fitness genes are enriched in similar functional categories.Our analysis demonstrates a considerable fuzzy essential zone determined by cofitness connectivity degrees in Sinorhizobium pangenome and highlights the power of the cofitness network in understanding the genetic basis of ever-increasing prokaryotic pangenome data.

毛细吸水作用对水泥砂浆电阻率的影响研究

采用四电极法测定了水泥砂浆电阻率随毛细吸水时间的变化,并分析了水灰比、聚合物乳液、引气剂对其变化的影响.研究表明:随毛细吸水时间的增加,水泥砂浆电阻率先缓慢降低,随后迅速下降,最后保持稳定;毛细吸水可使水泥砂浆电阻率降低70%以上,这可能与吸水后砂浆内部形成的孔隙导电通道有关;增大水灰比和掺入引气剂均可大幅度提高干燥条件下砂浆的电阻率,且对吸水状态下砂浆的电阻率也有一定提高作用,但对吸水后砂浆的电阻率影响不大;6%聚合物乳液掺量(聚合物的固含量占水泥质量的百分数)不仅可提高干燥条件下的砂浆电阻率,也可提高吸水后的砂浆电阻率(提高4倍左右,且保持在360Ω·m以上),原因可能与水灰比、聚合物乳液、引气剂对砂浆毛细孔隙结构的影响有关.

在有机化学实验中设置计算化学模块

计算化学快速发展,对于化学研究有非常强的指导作用,因此将其引入本科低年级实验教学很有必要。本文在调研国内外高校计算化学课程开设情况的基础上,根据本院学生特点和课程的需要,在面向大一本科生的核心实验课程——有机化学实验中引入了计算模块。模块设计从实验问题出发,将计算项目和实验紧密结合,采用分层次教学的模式进行。利用Canvas线上教学平台对微课、讲义、作业、测验等学习资源进行有效组织,通过直播课和微信群进行讨论和答疑,以翻转课堂的形式进行混合式教学,取得了很好的教学效果。

促聚合与生物矿化改善轨道板用钠水玻璃性能

为改善高铁轨道板涂料用钠水玻璃力学强度和耐水性,通过添加Ca(H2PO4)2,达到促进钠水玻璃生物矿化、提高硅氧聚合程度的目的.首先在钠水玻璃中添加Ca(H2PO4)2制作样品,以未添加Ca(H2PO4)2的样品作空白对照;然后用万能材料试验机、耐水性试验检测样品性能,并用X-射线衍射仪、傅里叶红外光谱仪、固体核磁共振仪测试其微观组成和结构.研究结果表明:Ca(H2PO4)2添加导致钠水玻璃力学强度提高160%,耐水性由浸水2 h完全溃散提高至浸水7 d无明显损坏;促使钠水玻璃仿生矿化形成力学强度高、耐水性好的人体骨主要无机成分Ca8H2(PO4)6?H2O-NaHCO3-H2O;增强钠水玻璃中硅氧的聚合,使之形成耐水性更好的硅氧聚合体.可推断得,添加Ca(H2PO4)2可明显提高钠水玻璃凝结硬化后力学强度和耐水性,具有应用于轨道板涂料的前景.

乳化沥青对水化硅酸钙孔结构及微观形貌的影响

针对未掺乳化沥青的纯水化硅酸钙和用Na2SiO3·9H2O,Ca(NO3)2·4H2O,NaOH,去离子水及阴离子乳化沥青合成的水化硅酸钙,采用氮吸附-脱附试验、X射线衍射(XRD)和扫描电镜(SEM)等测试方法对比研究了乳化沥青对水化硅酸钙孔结构及微观形貌的影响,并运用FHH模型分析了其表面分形特征.结果表明:纯水化硅酸钙和掺杂乳化沥青的水化硅酸钙比表面积相差较小,且微孔分布几乎一致,说明掺杂乳化沥青后插层作用和"开孔"效应并未发生;乳化沥青可促进水化硅酸钙形成孔径较大的中孔,减少孔径较小的中孔,而对大孔及微孔的孔结构几乎没有影响;纯水化硅酸钙和掺杂乳化沥青的水化硅酸钙表面分形特征存在差异;沥青表面乳化剂中的-COOM基团与Ca键合可使水化硅酸钙胶束包裹在乳化沥青颗粒表面.