An 8-Node Plane Hybrid Element for StructuralMechanics Problems Based on the Hellinger-Reissner Variational Principle

The finite element method (FEM) plays a valuable role in computer modeling and is beneficial to the mechanicaldesign of various structural parts. However, the elements produced by conventional FEM are easily inaccurate andunstable when applied. Therefore, developing new elements within the framework of the generalized variationalprinciple is of great significance. In this paper, an 8-node plane hybrid finite element with 15 parameters (PHQ8-15β) is developed for structural mechanics problems based on the Hellinger-Reissner variational principle.According to the design principle of Pian, 15 unknown parameters are adopted in the selection of stress modes toavoid the zero energy modes.Meanwhile, the stress functions within each element satisfy both the equilibrium andthe compatibility relations of plane stress problems. Subsequently, numerical examples are presented to illustrate theeffectiveness and robustness of the proposed finite element. Numerical results show that various common lockingbehaviors of plane elements can be overcome. The PH-Q8-15β element has excellent performance in all benchmarkproblems, especially for structures with varying cross sections. Furthermore, in bending problems, the reasonablemesh shape of the new element for curved edge structures is analyzed in detail, which can be a useful means toimprove numerical accuracy.

Effective inhibition of anomalous grain coarsening in cast AZ91 alloys during fast cooling via nanoparticle addition

In this work, the effects of Ti CN and γ-Al_(2)O_(3) nanoparticle(NP) addition on the microstructural evolution of cast AZ91 alloys at the cooling rate ranging from 15 to 120 K/s have been systematically investigated. Experimental results reveal that grain coarsening occurs in cast AZ91 alloys when the cooling rate exceeds 90 K/s, while it can be effectively inhibited upon addition of NPs. The marked inhibition effect may originate from the formation of Ti CN or γ-Al_(2)O_(3) NP-induced undercooling zone ahead of solid/liquid(S/L) front of α-Mg, which not only can restrict grain growth effectively, but also can reactivate the native nucleants that are inactive in AZ91 melts to participate in nucleation events. And if possessing high nucleation potency, NPs can also promote further nucleation events and lead to significant grain refinement. An analytical model has been established to quantitatively account for the restriction effect of NPs on grain growth. The present work may shed a new light on the grain coarsening of cast alloys during fast cooling and provide an effective approach to circumvent it.

A Spectral Convolutional Neural Network Model Based on Adaptive Fick’s Law for Hyperspectral Image Classification

Hyperspectral image classification stands as a pivotal task within the field of remote sensing,yet achieving highprecision classification remains a significant challenge.In response to this challenge,a Spectral Convolutional Neural Network model based on Adaptive Fick’s Law Algorithm(AFLA-SCNN)is proposed.The Adaptive Fick’s Law Algorithm(AFLA)constitutes a novel metaheuristic algorithm introduced herein,encompassing three new strategies:Adaptive weight factor,Gaussian mutation,and probability update policy.With adaptive weight factor,the algorithmcan adjust theweights according to the change in the number of iterations to improve the performance of the algorithm.Gaussianmutation helps the algorithm avoid falling into local optimal solutions and improves the searchability of the algorithm.The probability update strategy helps to improve the exploitability and adaptability of the algorithm.Within the AFLA-SCNN model,AFLA is employed to optimize two hyperparameters in the SCNN model,namely,“numEpochs”and“miniBatchSize”,to attain their optimal values.AFLA’s performance is initially validated across 28 functions in 10D,30D,and 50D for CEC2013 and 29 functions in 10D,30D,and 50D for CEC2017.Experimental results indicate AFLA’s marked performance superiority over nine other prominent optimization algorithms.Subsequently,the AFLA-SCNN model was compared with the Spectral Convolutional Neural Network model based on Fick’s Law Algorithm(FLA-SCNN),Spectral Convolutional Neural Network model based on Harris Hawks Optimization(HHO-SCNN),Spectral Convolutional Neural Network model based onDifferential Evolution(DE-SCNN),SpectralConvolutionalNeuralNetwork(SCNN)model,and SupportVector Machines(SVM)model using the Indian Pines dataset and PaviaUniversity dataset.The experimental results show that the AFLA-SCNN model outperforms other models in terms of Accuracy,Precision,Recall,and F1-score on Indian Pines and Pavia University.Among them,the Accuracy of the AFLA-SCNN model on Indian Pines reached 99.875%,and the Accuracy on PaviaUniversity reached 98.022%.In conclusion,our proposed AFLA-SCNN model is deemed to significantly enhance the precision of hyperspectral image classification.

Research on the Control Strategy of Micro Wind-Hydrogen Coupled System Based on Wind Power Prediction and Hydrogen Storage System Charging/Discharging Regulation

This paper addresses the micro wind-hydrogen coupled system,aiming to improve the power tracking capability of micro wind farms,the regulation capability of hydrogen storage systems,and to mitigate the volatility of wind power generation.A predictive control strategy for the micro wind-hydrogen coupled system is proposed based on the ultra-short-term wind power prediction,the hydrogen storage state division interval,and the daily scheduled output of wind power generation.The control strategy maximizes the power tracking capability,the regulation capability of the hydrogen storage system,and the fluctuation of the joint output of the wind-hydrogen coupled system as the objective functions,and adaptively optimizes the control coefficients of the hydrogen storage interval and the output parameters of the system by the combined sigmoid function and particle swarm algorithm(sigmoid-PSO).Compared with the real-time control strategy,the proposed predictive control strategy can significantly improve the output tracking capability of the wind-hydrogen coupling system,minimize the gap between the actual output and the predicted output,significantly enhance the regulation capability of the hydrogen storage system,and mitigate the power output fluctuation of the wind-hydrogen integrated system,which has a broad practical application prospect.

KCNJ15 deficiency promotes drug resistance via affecting the function of lysosomes

The altered lysosomal function can induce drug redistribution which leads to drug resistance and poor prognosis for cancer patients.V-ATPase,an ATP-driven proton pump positioned at lysosomal surfaces,is responsible for maintaining the stability of lysosome.Herein,we reported that the potassium voltage-gated channel subfamily J member 15(KCNJ15)protein,which may bind to V-ATPase,can regulate the function of lysosome.The deficiency of KCNJ15 protein in breast cancer cells led to drug aggregation as well as reduction of drug efficacy.The application of the V-ATPase inhibitor could inhibit the binding between KCNJ15 and V-ATPase,contributing to the amelioration of drug resistance.Clinical data analysis revealed that KCNJ15 deficiency was associated with higher histological grading,advanced stages,more metastases of lymph nodes,and shorter disease free survival of patients with breast cancer.KCNJ15 expression level is positively correlated with a high response rate after receiving neoadjuvant chemotherapy.Moreover,we revealed that the small molecule drug CMA/BAF can reverse drug resistance by disrupting the interaction between KCNJ15 and lysosomes.In conclusion,KCNJ15 could be identified as an underlying indicator for drug resistance and survival of breast cancer,which might guide the choice of therapeutic strategies.

Laser patterning of large-scale perovskite single-crystal-based arrays for single-mode laser displays

Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.

突发公共事件下的员工远程办公——进展与未来展望

突发公共事件极大地加快了企业远程办公的进度。为了进一步了解突发公共事件对企业远程办公的影响,本文梳理了2020年初至今远程办公的最新研究,并与之前的研究结果进行了对比、回顾、评述和展望。首先,从相关学科重要的中英文期刊中甄选出59篇主题相关文章,回顾并比较了突发公共事件发生前后的研究进展。其次,本文阐释了突发公共事件发生前后远程办公的内涵演变,并比较了对员工身心健康和工作表现影响结果的异同,进而基于组织行为的情境理论,构建了突发公共事件下的员工远程办公作用机制和影响效果框架图。最后,本文探讨了当前突发公共事件下远程办公的研究方向。

Recent Advances in Soft Biological Tissue Manipulating Technologies

Biological soft tissues manipulation,including conventional(mechanical)and nonconventional(laser,waterjet and ultrasonic)processes,is critically required in most surgical innervations.However,the soft tissues,with their nature of anisotropic and viscoelastic mechanical properties,and high biological and heat sensitivities,are difficult to manipulated.Moreover,the mechanical and thermal induced damage on the surface and surrounding tissue during the surgery can impair the proliferative phase of healing.Thus,understanding the manipulation mechanism and the resulted surface damage is of importance to the community.In recent years,more and more scholars carried out researches on soft biological tissue cutting in order to improve the cutting performance of surgical instruments and reduce the surgery induced tissue damage.However,there is a lack of compressive review that focused on the recent advances in soft biological tissue manipulating technologies.Hence,this review paper attempts to provide an informative literature survey of the state-of-the-art of soft tissue manipulation processes in surgery.This is achieved by exploring and recollecting the different soft tissue manipulation techniques currently used,including mechanical,laser,waterjet and ultrasonic cutting and advanced anastomosis and reconstruction processes,with highlighting their governing removal mechanisms as well as the surface and subsurface damages.

Engineered macrophage-biomimetic versatile nanoantidotes for inflammation-targeted therapy against Alzheimer’s disease by neurotoxin neutralization and immune recognition suppression

Immune recognition of excessive neurotoxins by microglia is a trigger for the onset of neuroinflammation in the brain,leading to neurodegeneration in Alzheimer’s disease(AD).Blocking active recognition of microglia while removing neurotoxins holds promise for fundamentally alleviating neurotoxin-induced immune responses,but is very challenging.Herein,an engineered macrophage-biomimetic versatile nanoantidote(OT-Lipo@M)is developed for inflammation-targeted therapy against AD by neurotoxin neutralization and immune recognition suppression.Coating macrophage membranes can not only endow OT-Lipo@M with anti-phagocytic and inflammation-tropism capabilities to target inflammatory lesions in AD brain,but also efficiently reduce neurotoxin levels to prevent them from activating microglia.The loaded oxytocin(OT)can be slowly released to downregulate the expression of immune recognition site Toll-like receptor 4(TLR4)on microglia,inhibiting TLR4-mediated pro-inflammatory signalling cascade.Benefiting from this two-pronged immunosuppressive strategy,OT-Lipo@M exhibits outstanding therapeutic effects on ameliorating cognitive deficits,inhibiting neuronal apoptosis,and enhancing synaptic plasticity in AD mice,accompanied by the delayed hippocampal atrophy and brain microstructural disruption by in vivo 9.4T MR imaging.This work provides new insights into potential AD therapeutics targeting microglia-mediated neuroinflammation at the source.

Optimal Design of a Ship Multitasking Cabin Layout Based on the Interval Optimization Method

Searching for the optimal cabin layout plan is an efective way to improve the efciency of the overall design and reduce a ship’s operation costs.The multitasking states of a ship involve several statuses when facing diferent missions during a voyage,such as the status of the marine supply and emergency escape.The human fow and logistics between cabins will change as the state changes.An ideal cabin layout plan,which is directly impacted by the above-mentioned factors,can meet the diferent requirements of several statuses to a higher degree.Inevitable deviations exist in the quantifcation of human fow and logistics.Moreover,uncontrollability is present in the fow situation during actual operations.The coupling of these deviations and uncontrollability shows typical uncertainties,which must be considered in the design process.Thus,it is important to integrate the demands of the human fow and logistics in multiple states into an uncertainty parameter scheme.This research considers the uncertainties of adjacent and circulating strengths obtained after quantifying the human fow and logistics.Interval numbers are used to integrate them,a two-layer nested system of interval optimization is introduced,and diferent optimization algorithms are substituted for solving calculations.The comparison and analysis of the calculation results with deterministic optimization show that the conclusions obtained can provide feasible guidance for cabin layout scheme.

Fracture behavior and self-sharpening mechanisms of polycrystalline cubic boron nitride in grinding based on cohesive element method

Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts have been devoted to the study of PCBN applications in manufacturing engineering. Most of the studies, however, remain qualitative due to difficulties in experimental observations and theoretical modeling and provide limited in-depth understanding of the self-sharpening behavior/mechanism. To fill this research gap, the present study investigates the self-sharpening process of PCBN abrasives in grinding and analyzes the macro-scale fracture behavior and highly localized micro-scale crack propagation in detail. The widely employed finite element(FE) method, together with the classic Voronoi diagram and cohesive element technique,is used considering the pronounced success of FE applications in polycrystalline material modeling.Grinding trials with careful observation of the PCBN abrasive morphologies are performed to validate the proposed method. The self-sharpening details, including fracture morphology, grinding force, strain energy, and damage dissipation energy, are studied. The effects of maximum grain cut depths(MGCDs) and grinding speeds on the PCBN fracture behavior are discussed, and their optimum ranges for preferable PCBN self-sharpening performance are suggested.

Cross-species single-cell transcriptomic analysis reveals divergence of cell composition and functions in mammalian ileum epithelium

Animal models are widely used for biomedical studies and drug evaluation.The small intestine plays key roles in nutrient absorption,hormone secretion,microbiota defense and drug absorption and metabolism.Although the intestinal structure of mammals is conserved,the differences on epithelial cell composition,functional assignments and drug absorption among mammals are largely unknown.Here,cross-species analysis of single-cell transcriptomic atlas of the ileum epithelium from mouse,rat,pig,macaque and human reveals the conserved and differential cell types and functions among species,identifies a new CA7+cell type in pig,macaque and human ileum,uncovers the distinct expression pattern in enterocytes,enteroendocrine cells and Paneth cells,and defines the conserved and species-specific intestinal stem cell signature genes.The examination of drug absorption across species suggests that drug metabolism in mouse ileum is closer to human while drug transport in macaque ileum is more similar to human.Together,our data provide the comprehensive information about cell composition and functional assignments in five species,and offer the valuable guidance for animal model selection and drug testing.

Establishment of porcine and monkey colonic organoids for drug toxicity study

Pig and monkey are widely used models for exploration of human diseases and evaluation of drug efficiency and toxicity,but high cost limits their uses.Organoids have been shown to be promising models for drug test as they reasonably preserve tissue structure and functions.However,colonic organoids of pig and monkey are not yet established.Here,we report a culture medium to support the growth of porcine and monkey colonic organoids.Wnt signaling and PGE2 are important for long-term expansion of the organoids,and their withdrawal results in lineage differentiation to mature cells.Furthermore,we observe that porcine colonic organoids are closer to human colonic organoids in terms of drug toxicity response.Successful establishment of porcine and monkey colonic organoids would facilitate the mechanistic investigation of the homeostatic regulation of the intestine of these animals and is useful for drug development and toxicity studies.

Cross-species single-cell transcriptomic analysis of animal gastric antrum reveals intense porcine mucosal immunity

As an important part of the stomach,gastric antrum secretes gastrin which can regulate acid secretion and gastric emptying.Although most cell types in the gastric antrum are identified,the comparison of cell composition and gene expression in the gastric antrum among different species are not explored.In this study,we collected antrum epithelial tissues from human,pig,rat and mouse for scRNA-seq and compared cell types and gene expression among species.In pig antral epithelium,we identified a novel cell cluster,which is marked by high expression of AQP5,F3,CLCA1 and RRAD.We also discovered that the porcine antral epithelium has stronger immune function than the other species.Further analysis revealed that this may be due to the insufficient function of porcine immune cells.Together,our results replenish the information of multiple species of gastric antral epithelium at the single cell level and provide resources for understanding the homeostasis maintenance and regeneration of gastric antrum epithelium.

纳秒激光调控CFRP复合材料表面润湿性及其对胶接性能的影响

采用纳秒激光对碳纤维增强树脂基(CFRP)复合材料进行表面预处理,调控其表面成分、粗糙度和表面润湿性,然后采用SEM、接触角测量仪、光学轮廓仪、XPS等表征CFRP复合材料的表面微观形貌、接触角、粗糙度和化学成分,并通过拉伸剪切实验评价和分析激光表面处理对CFRP复合材料胶接强度的影响规律和机制。结果表明:优化激光表面处理参数,可以去除CFRP复合材料表面的环氧树脂胶,调控其表面成分、粗糙度和表面润湿性;与未处理的CFRP复合材料相比,激光表面处理后的CFRP复合材料表面化学成分改变,表面粗糙度有所增加,润湿性提高,胶接强度也增大;与未处理CFRP复合材料相比,激光离焦量分别为5 mm、10 mm和15 mm时,处理后的CFRP复合材料胶接强度分别提高了129.41%、112.13%和105.88%;激光表面处理CFRP复合材料的表面润湿性和表面粗糙度均高于机械处理CFRP复合材料,但激光处理导致的热损伤对胶接强度提高有负面影响。

领导-成员交换如何以及何时影响员工偏离行为?社会控制理论的视角

领导-成员交换是组织人际关系研究的重要组成部分,一直以来受到研究者的广泛关注。然而,当员工作为领导者的"圈内人"时,似乎容易受到领导者的特殊"保护",并从事偏离行为。基于社会控制理论,本研究采用多来源的问卷调查方法,探讨了领导-成员交换的消极面。研究结果表明:高质量的领导-成员交换关系导致员工产生感知偏离容忍,进而导致其偏离行为增加。这一过程又受到员工道德推脱水平的调节作用,即当员工的道德推脱水平较高时,领导-成员交换通过员工的感知偏离容忍正向影响其偏离行为的间接效应显著;当员工的道德推脱水平较低时,上述间接效应不显著。本研究为领导-成员交换提供了更加全面和辩证的研究视角,同时也拓展了社会控制理论、感知偏离容忍和偏离行为的相关研究。除此之外,本研究也为企业管理实践提供了可供借鉴的经验和指导。

Oil-polluted water purification via the carbon-nanotubes-doped organohydrogel platform

Solar-driven evaporators are promising for tackling freshwater scarcity but still challenged in simultaneously realizing comprehensive performances at one platform for sustainable and efficient application in real-world environments,such as stablefloating,scalability,salt-resistance,efficient vaporization,and anti-oil-fouling property.Herein,we design a hybrid organohydrogel evaporator to achieve the enduring oil contamination repulsion with maintaining accelerated evaporation process,and integrate capacities of ultra-stable floating,hindered salt-crystallization,large-scale fabrication for practical purification of seawater and polluted solutions.The raised water surface surrounding evaporators,induced by low density of organogel-phase,results in oil contamination resistance through the lateral capillary repulsion effect.Meanwhile,the organogel-phase containing photo-thermal carbon-nanotubes with low thermal capacity and conduction can form locally confined hot dots under solar irradiation and reduce heat dissipation on heating excessive water.Therefore,based on this approach,accelerated long-term practical purification of oilcontaminated solutions without any extra disposal is realized.Considering other properties of ultra-stable floating,large-scale fabrication,and anti-salt crystallization,these innovative organohydrogel evaporators open pathways for purifying oil-slickpolluted water via interfacial evaporation and are anticipated accelerating industrialization of efficient and sustainable solar-driven water purification.

纳米圆轴在弹性介质中的扭转振动分析

基于非局部应变梯度理论,结合Winkler模型,考虑周围弹性介质的影响,研究纳米圆轴的扭转自由振动.首先通过Hamilton原理推导纳米圆轴扭转振动的控制方程及边界条件,接着采用微分求积法得到控制方程及三类边界条件的离散形式,最后由数值计算结果分析扭转振动特性.讨论了细长度、两个小尺度参数及其比值、弹性介质刚度对振动频率的影响.研究结果表明,扭转自由振动频率随细长度、非局部参数增加而减小,随应变梯度尺度参数、弹性介质刚度增加而增大;当非局部参数大于应变梯度尺度参数时,小尺度效应体现为非局部效应,相反则体现为应变梯度效应.

Orogenic Movements during the Paleozoic Period: Development of the Granitoid Formations in the Northwestern Region of Spain’s Iberian Peninsula

In the present study,Paleozoic Variscan orogenesis was a model of the oroclinal flexion accompanied by extensive magmatism,which could be divided into the following two types:post-tectonic and syn-tectonic tonalite granite,and leuco-granite which were controlled by the tectonic characteristics of the intrusions.It was observed that a very high majority of the samples had displayed discontinuities in their structures,that were later utilized to define the granitoid morphology and development characteristics of the rock during the intrusion phases.Furthermore,it was determined that the tectonics associated with the Alpine orogeny results in the new generation of faults and fractures during the Paleogene Period had produced the development of the Sierras.Due to different weathering processes,the depressions which had resulted in the present granitoid reliefs were found to be exclusively related to the structural development processes during the geological history(either tectonic or magmatic)of the granite,and not as normally interpreted.