The Influence of Crystallographic Orientation and Grain Boundary on Nanoindentation Behavior of Inconel 718 Superalloy Based on Crystal Plasticity Theory

The crystal plasticity finite element method(CPFEM)is widely used to explore the microscopic mechanical behavior of materials and understand the deformation mechanism at the grain-level.However,few CPFEM simulation studies have been carried out to analyze the nanoindentation deformation mechanism of polycrystalline materials at the microscale level.In this study,a three-dimensional CPFEM-based nanoindentation simulation is performed on an Inconel 718 polycrystalline material to examine the influence of different crystallographic parameters on nanoindentation behavior.A representative volume element model is developed to calibrate the crystal plastic constitutive parameters by comparing the stress-strain data with the experimental results.The indentation force-displacement curves,stress distributions,and pile-up patterns are obtained by CPFEM simulation.The results show that the crystallographic orientation and grain boundary have little influence on the force-displacement curves of the nanoindentation,but significantly influence the local stress distributions and shape of the pile-up patterns.As the difference in crystallographic orientation between grains increases,changes in the pile-up patterns and stress distributions caused by this effect become more significant.In addition,the simulation results reveal that the existence of grain boundaries affects the continuity of the stress distribution.The obstruction on the continuity of stress distribution increases as the grain boundary angle increases.This research demonstrates that the proposed CPFEM model can well describe the microscopic compressive deformation behaviors of Inconel 718 under nanoindentation.

High-performance triboelectric nanogenerator based on ZrB_(2)/polydimethylsiloxane for metal corrosion protection

Metal corrosion causes billions of dollars of economic losses yearly.As a smart and new energy-harvesting device,triboelectric nanogenerators(TENGs)can convert almost all mechanical energy into electricity,which leads to great prospects in metal corrosion prevention and cathodic protection.In this work,flexible TENGs were designed to use the energy harvested by flexible polydimethylsiloxane(PDMS)films with ZrB_(2)nanoparticles and effectively improve the dielectric constant by incorporating ZrB_(2).The open-circuit voltage and short-circuit current were 264 V and 22.9μA,respectively,and the power density of the TENGs reached 6 W·m^(-2).Furthermore,a selfpowered anti-corrosion system was designed by the rectifier circuit integrated with TENGs,and the open-circuit potential(OCP)and Tafel curves showed that the system had an excellent anti-corrosion effect on carbon steel.Thus,the system has broad application prospects in fields such as metal cultural relics,ocean engineering,and industry.

Ash Detection of Coal Slime Flotation Tailings Based on Chromatographic Filter Paper Sampling and Multi-Scale Residual Network

The detection of ash content in coal slime flotation tailings using deep learning can be hindered by various factors such as foam,impurities,and changing lighting conditions that disrupt the collection of tailings images.To address this challenge,we present a method for ash content detection in coal slime flotation tailings.This method utilizes chromatographic filter paper sampling and a multi-scale residual network,which we refer to as MRCN.Initially,tailings are sampled using chromatographic filter paper to obtain static tailings images,effectively isolating interference factors at the flotation site.Subsequently,the MRCN,consisting of a multi-scale residual network,is employed to extract image features and compute ash content.Within the MRCN structure,tailings images undergo convolution operations through two parallel branches that utilize convolution kernels of different sizes,enabling the extraction of image features at various scales and capturing a more comprehensive representation of the ash content information.Furthermore,a channel attention mechanism is integrated to enhance the performance of the model.The combination of the multi-scale residual structure and the channel attention mechanism within MRCN results in robust capabilities for image feature extraction and ash content detection.Comparative experiments demonstrate that this proposed approach,based on chromatographic filter paper sampling and the multi-scale residual network,exhibits significantly superior performance in the detection of ash content in coal slime flotation tailings.

弹性体对聚丙烯基电缆绝缘材料力学及介电性能的影响

文中对聚烯烃弹性体(POE)和晶型调控聚丙烯基绝缘材料(PPB)共混体系的力学性能及介电性能进行了研究,探讨了弹性体含量对材料性能的影响。采用扫描电子显微镜和差示扫描量热仪研究了共混物的相态结构及熔融结晶特性。结果表明,POE与基体的相容性较好,有良好的分散性,弹性体的引入对共混物的熔融及结晶特性无明显影响。通过拉伸试验和动态力学热分析说明,共混物的力学性能得到了明显改善,当POE的质量分数为40%时,断裂伸长率为632.05%,提高了约20%,弹性模量降低了50%,低温韧性也有所提高;介电频谱、交流击穿等实验表明,POE质量分数不超过40%时,该体系更大程度地维持了基体的电性能,具有潜在的工程应用价值。

First report of leaf-spot disease caused by Sphaeropsis visci on Asian mistletoe [Viscum coloratum (Kom.) Nakai] in China

In January 2017, symptoms of a leaf-spot disease were observed on Viscum coloratum plants in Yichun,China. The infected leaves were chlorotic, while sunken lesions formed on diseased branches, which were initially light brown and later turned dark brown. Moreover, diseased branches and leaves formed semi-buried, small, and spherical pycnidia. In total, 20 leaves and 19 branches diseased samples from Yichun, China were collected and examined. The fungus was isolated and identified using Koch’s postulates, morphological characteristics and DNA sequence data. The data presented herein confirmed that the pathogen responsible for the disease was Sphaeropsis visci. To the best of our knowledge, this is the first report of it in China.

Dynamics of NDVI and its influencing factors in the Chinese Loess Plateau during 2002-2018

Understanding the spatio-temporal changes of vegetation and its climatic control factors can provide an important theoretical basis for the protection and restoration of eco-environments.In this study,we analyzed the normalized difference vegetation index(NDVI)in the Chinese Loess Plateau(CLP)from 2002 to 2018 via trend analysis,stability analysis,and Mann-Kendall mutation test to investigate the change of vegetation.In addition,we also used the skewness analysis and correlation analysis to explore the contribution of climate change and human activities on regional vegetation changes.The results indicated that the overall increasing trend of NDVI from 2002 to 2018 was significant The areas showing increased NDVI were mainly distributed in the south-eastern CLP and the irrigation districts of the Yellow River to the north and west of the CLP,while the areas showing decreased NDVl were concentrated in the desert of the westem Ordos Plateau,Longzhong Loess Plateau,and the built-up and adjacent areas.Precipitation was the dominant factor contributing to vegetation growth in the CLP,while vegetation was less dependent onprecipitation in the irigation districts.The increasement of NDVI has led to a prolonged responsetime of vegetation to water stress and a lag effect of less than two months in the CLP.The effect of temperature on NDVI was not significant;significant negative correlations between NDVI and temperature were found only in the desert,the Guanzhong Plain,the southem Liupan Mountains,and the southeastem Taihang Mountains,owing to high temperatures,urban heat islands,and large cloud cover in mountainous areas.Affected by the"Grain for Green Program"(GGP),NDVIin the CLP increased from 2002 to 2018;however,the increasing trends of NDNI for differentvegetation cover types were significantly different owing to the difference in background status.The increasing contribution rate of NDVI in the CLP mainly came from crops and steppes.Urban not only led to the destruction of vegetation but also had radiation effect causing negative impact of NDVI around the cities.This resulted in the aggravation of the negative bias of NDVI with time in the CLP.The results provide a long-term perspective for regional vegetation protection and utilization in the CLP.

OBH-RSI:Object-Based Hierarchical Classification Using Remote Sensing Indices for Coastal Wetland

With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset.

An improved lightweight network based on deep learning for grape recognition in unstructured environments

In unstructured environments,dense grape fruit growth and the presence of occlusion cause difficult recognition problems,which will seriously affect the performance of grape picking robots.To address these problems,this study improves the YOLOx-Tiny model and proposes a new grape detection model,YOLOX-RA,which can quickly and accurately identify densely growing and occluded grape bunches.The proposed YOLOX-RA model uses a 3×3 convolutional layer with a step size of 2 to replace the focal layer to reduce the computational burden.The CBS layer in the ResBlock_Body module of the second,third,and fourth layers of the backbone layer is removed,and the CSPLayer module is replaced by the ResBlock-M module to speed up the detection.An auxiliary network(AlNet)with the remaining network blocks was added after the ResBlock-M module to improve the detection accuracy.Two depth-separable convolutions(DsC)are used in the neck module layer to replace the normal convolution to reduce the computational cost.We evaluated the detection performance of SSD,YOLOv4 SSD,YOLOv4-Tiny,YOLO-Grape,YOLOv5-X,YOLOX-Tiny,and YOLOX-RA on a grape test set.The results show that the YOLOX-RA model has the best detection performance,achieving 88.75%mAP,a recognition speed of 84.88 FPS,and model size of 17.53 MB.It can accurately detect densely grown and shaded grape bunches,which can effectively improve the performance of the grape picking robot.

Pharmacokinetic enhancement of oncolytic virus M1 by inhibiting JAK-STAT pathway

Oncolytic viruses(OVs),a group of replication-competent viruses that can selectively infect and kill cancer cells while leaving healthy cells intact,are emerging as promising living anticancer agents.Unlike traditional drugs composed of non-replicating compounds or biomolecules,the replicative nature of viruses confer unique pharmacokinetic properties that require further studies.Despite some pharmacokinetics studies of OVs,mechanistic insights into the connection between OV pharmacokinetics and antitumor efficacy remain vague.Here,we characterized the pharmacokinetic profile of oncolytic virus M1(OVM)in immunocompetent mouse tumor models and identified the JAK-STAT pathway as a key modulator of OVM pharmacokinetics.By suppressing the JAK-STAT pathway,early OVM pharmacokinetics are ameliorated,leading to enhanced tumor-specific viral accumulation,increased AUC and Cmax,and improved antitumor efficacy.Rather than compromising antitumor immunity after JAK-STAT inhibition,the improved pharmacokinetics of OVM promotes T cell recruitment and activation in the tumor microenvironment,providing an optimal opportunity for the therapeutic outcome of immune checkpoint blockade,such as anti-PD-L1.Taken together,this study advances our understanding of the pharmacokinetic-pharmacodynamic relationship in OV therapy.

Energy storage optimization of ferroelectric ceramics during phase-transition process of amorphous/nanocrystalline and polycrystalline by using a phaseffeld model for dielectric breakdown

Ferroelectric ceramics have the potential to be widely applied in the modern industry and military power systems due to their ultrafast charging/discharging speed and high energy density.Considering the structural design and electrical properties of ferroelectric capacitor,it is still a challenge to ffnd out the optimal energy storage of ferroelectric ceramics during the phase-transition process of amorphous/nanocrystalline and polycrystalline.In this work,a ffnite element model suitable for the multiphase ceramic system is constructed based on the phase ffeld breakdown theory.The nonlinear coupling relationship of multiple physical ffelds between multiphase ceramics was taken into account in this model.The basic structures of multiphase ceramics are generated by using the Voronoi diagram construction method.The speciffed structure of multiphase ceramics in the phase-transition process of amorphous/nanocrystalline and polycrystalline was further obtained through the grain boundary diffusion equation.The simulation results show that the multiphase ceramics have an optimal energy storage in the process of amorphous polycrystalline transformation,and the energy storage density reaches the maximum when the crystallinity is 13.96%and the volume fraction of grain is 2.08%.It provides a research plan and idea for revealing the correlation between microstructure and breakdown characteristics of multiphase ceramics.This simulation model realizes the nonlinear coupling of the multiphase ceramic mesoscopic structure and the phase ffeld breakdown.It provides a reference scheme for the structural design and performance optimization of ferroelectric ceramics.

Broadband impedance spectrum detection of buffer layer defects in 110 kV crosslinked polyethylene cable with corrugated aluminium sheath

The buffer layer defects of high‐voltage crosslinked polyethylene(XLPE)cable occur frequently,which makes the detection method become the focus to be studied.Here,the broadband impedance detection technology for the buffer layer defects of high‐voltage XLPE cables with corrugated aluminium sheath is investigated.There are nine cable samples,including new and defective ones.Some of the defective cables are artificial,and the other is retired cables.The influence of wiring mode,the circumferential relative position of electrodes,cable length,artificial white powder,artificial damp,and retired defective cables on the impedance spectrum is studied.It is found that the wiring mode of the insulation shield/aluminium sheath at the end of the cable can effectively detect the buffer layer defects.And the broadband impedance amplitude spectrum of the buffer layer in defective cable,measuring at various circumferential relative positions,is obviously different.When there are white powders,air gaps,or ablation in the buffer layer,the broadband impedance spectrum(BIS)will increase by several times.When the buffer layer is damped,the BIS will reduce.The research here provides theoretical support and technical methods for the buffer layer defects of XLPE cable with corrugated aluminium sheath.

Synthesis of taurine-fluorescein conjugate and evaluation of its retina-targeted efficiency in vitro

In this work, retinal penetration of fluorescein was achieved in vitro by covalent attachment of taurine to fluorescein, yielding the F-Tau conjugate. Nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS) were used to confirm the successful synthesis of F-Tau. The cellular uptake of F-Tau in adult retinal pigment epithelial cells (ARPE-19) and human retinal microvascular endothelial cells (hRMECs) was visualized via confocal scanning microscopy. The results indicated an improvement of solubility and a reduction of logP of F-Tau compared with fluorescein. As compared with fluorescein, F-Tau showed little toxicity, and was retained longer by cells in uptake experiments. F-Tau also displayed higher transepithelial permeabilities than fluorescein in ARPE-19 and hRMECs monolayer cells (Po0.05). These results showed that taurine may be a useful ligand for targeting small-molecule hydrophobic pharmaceuticals into the retina.

Spatial variations of terrain and their impacts on landscape patterns in the transition zone from mountains to plains—A case study of Qihe River Basin in the Taihang Mountains

Terrain plays a key role in landscape pattern formation, particularly in the transition zones from mountains to plains.Exploring the relationships between terrain characteristics and landscape types in terrain-complex areas can help reveal the mechanisms underlying the relationships. In this study, Qihe River Basin, situated in the transition zone from the Taihang Mountains to the North-China Plain, was selected as a case study area. First, the spatial variations in the relief amplitudes(i.e.,high-amplitude terrain undulations) were analyzed. Second, the effects of relief amplitudes on the landscape patterns were indepth investigated from the perspectives of both landscape types and landscape indices. Finally, a logistic regression model was employed to examine the relationships between the landscape patterns and the influencing factors(natural and human) at different relief amplitudes. The results show that with increasing relief amplitude, anthropogenic landscapes gradually give in to natral landscapes. Specifically, human factors normally dominate the gentle areas(e.g., flat areas) in influencing the distribution of landscape types, and natural factors normally dominate the highly-undulating areas(e.g., moderate relief areas). As for the intermediately undulating areas(i.e.,medium relief amplitudes), a combined influence of natural and human factors result in the highest varieties of landscape types. The results also show that in micro-relief areas and small relief areas where natural factors and human factors are more or less equally active,landscape types are affected by a combination of natural and human factors.The combination leads to a high fragmentation and a high diversity of landscape patterns. It seems that appropriate human interferences in these areas can be conducive to enhancing landscape diversity and that inappropriate human interferences can aggravate the problems of landscape fragmentation.

Effects of ZnO magnetron sputtering on surface charge and flashover voltage of oilimpregnated paper

With the aim of exploring an alternative method of nano-doping in cellulose paper and improving flashover strength of oil-impregnated paper,radio frequency(RF)magnetron sputtering method is introduced into the structural modification of insulating paper for converter transformers.In this experiment,insulating paper was treated with ZnO sputtering for 0,7.5,15 and 30 min,respectively.The surface morphology of dry paper was observed with a scanning electron microscope.The bonding mode of sputtered ZnO particles with cellulose matrix was investigated via attenuated total reflection infrared(ATR-IR)spectroscopy and mechanical property of the sputtered samples were studied.Surface and volume conductivities of the oilimpregnated sputtered paper were measured.Moreover,the charge dissipation characteristics of sputtered insulating paper was investigated by means of surface potential decay.In addition,trap distribution and carrier mobility of specimen were further obtained.Finally,the DC flashover strength were tested.The results showed that ZnO magnetron sputtering had a distinct influence on the structure of the insulating paper,resulting in the formation of hydrogen bond and chemical bond and an increase of the surface and volume conductivities.ZnO sputtering was found to decrease the initial potential and accelerate charge decay.Moreover,appropriate sputtering enhanced the surface flashover strength.

Identification of the receptor of oncolytic virus M1 as a therapeutic predictor for multiple solid tumors

Over the last decade,oncolytic virus(OV)therapy has shown its promising potential in tumor treatment.The fact that not every patient can benefit from it highlights the importance for defining biomarkers that help predict patients’responses.As particular self-amplifying biotherapeutics,the anti-tumor effects of OVs are highly dependent on the host factors for viral infection and replication.By using weighted gene co-expression network analysis(WGCNA),we found matrix remodeling associated 8(MXRA8)is positively correlated with the oncolysis induced by oncolytic virus M1(OVM).

Challenges of COVID-19 vaccination in patients with cancer

Patients with cancer are at increased risk of SARA-CoV-2 infection or developing severe COVID-19 cases due to malignancy or immunosuppressive therapy,but they are generally excluded from the target population for COVID-19 vaccination.In general,inactivated vaccines are safe and immunogenic for patients with cancer,but live attenuated vaccines are not recommended.The study suggested that the safety of the mRNA COVID-19 vaccine in patients with cancer is similar to that in healthy people,but immunogenicity is slightly weaker,and a booster dose may be needed.This paper aims to summarize the results of COVID-19 vaccine clinical studies conducted in patients with cancer worldwide and the relevant guidelines released by authorities,so as to provide evidence for promoting COVID-19 vaccination for patients with cancer.

Visualization of the Oncolytic Alphavirus M1 Life Cycle in Cancer Cells

Oncolytic alphavirus M1 has been shown to selectively target and kill cancer cells,but cytopathic morphologies induced by M1 virus and the life cycle of the M1 strain in cancer cells remain unclear.Here,we study the key stages of M1 virus infection and replication in the M1 virus-sensitive HepG2 liver cancer cell line by transmission electron microscopy,specifically examining viral entry,assembly,maturation and release.We found that M1 virus induces vacuolization of cancer cells during infection and ultimately nuclear marginalization,a typical indicator of apoptosis.Specifically,our results suggest that the endoplasmic reticulum participates in the assembly of nucleocapsids.In the early and late stage of infection,three kinds of special cytopathic vacuoles are formed and appear to be involved in the replication,maturation and release of the virus.Taken together,our data displayed the process of M1 virus infection of tumor cells and provide the structural basis for the study of M1 virus-host interactions.

Correction to:Visualization of the Oncolytic Alphavirus M1 Life Cycle in Cancer Cells

Correction to:Virologica Sinica(2021)https://doi.org/10.1007/s12250-020-00339-7 In the original version of Fig.6,published on January 22,2021,the names of image panels(row 2 to row 5)were mislabeled during figure layout.The corrected figure is shown below.The original article has been corrected.

Morphology simulation of drop-on-demand inkjet-printed droplets

Inkjet-printed electronics have become a popular research topic in recent years.For common drop-on-demand(DOD)inkjet printing technology,uneven edges are a universal problem.Many factors,such as the properties of the ink and printing parameters,influence this problem,and numerical methods are better than experimental methods for studying these influences.In this paper,a model based on the Volume of Fluid(VOF)method and user-defined files(UDFs)in Ansys F is established to simulate the formation process of deposited ink droplets.The model and UDFs include the friction effect,and the morphology of a single droplet,two fused droplets,and multiple droplets is simulated to study the influence of different factors;some results can serve as guidelines for improving pattern quality.Finally,the effect of selective treatment is also studied to understand its advantages for inkjet printing.

Advances in osseointegration of biomimetic mineralized collagen and inorganic metal elements of natural bone for bone repair

At this stage,bone defects caused by trauma,infection,tumor,or congenital diseases are generally filled with autologous bone or allogeneic bone transplantation,but this treatment method has limited sources,potential disease transmission and other problems.Ideal bone-graft materials remain continuously explored,and bone defect reconstruction remains a significant challenge.Mineralized collagen prepared by bionic mineralization combining organic polymer collagen with inorganic mineral calcium phosphate can effectively imitate the composition and hierarchical structure of natural bone and has good application value in bone repair materials.Magnesium,strontium,zinc and other inorganic components not only can activate relevant signaling pathways to induce differentiation of osteogenic precursor cells but also stimulate other core biological processes of bone tissue growth and play an important role in natural bone growth,and bone repair and reconstruction.This study reviewed the advances in hydroxyapatite/collagen composite scaffolds and osseointegration with natural bone inorganic components,such as magnesium,strontium and zinc.