Multiscale Finite Element Method for Coupling Analysis of Heterogeneous Magneto-Electro-Elastic Structures in Thermal Environment

Magneto-electro-elastic (MEE) materials, a new type of composite intelligent materials, exhibit excellent multifield coupling effects. Due to the heterogeneity of the materials, it is challenging to use the traditional finite element method (FEM) for mechanical analysis. Additionally, the MEE materials are often in a complex service environment, especially under the influence of the thermal field with thermoelectric and thermomagnetic effects, which affect its mechanical properties. Therefore, this paper proposes the efficient multiscale computational method for the multifield coupling problem of heterogeneous MEE structures under the thermal environment. The method constructs a multi-physics field with numerical base functions (the displacement, electric potential, and magnetic potential multiscale base functions). It equates a single cell of heterogeneous MEE materials to a macroscopic unit and supplements the macroscopic model with a microscopic model. This allows the problem to be solved directly on a macroscopic scale. Finally, the numerical simulation results demonstrate that compared with the traditional FEM, the multiscale finite element method (MsFEM) can achieve the purpose of ensuring accuracy and reducing the degree of freedom, and significantly improving the calculation efficiency.

A Review on Graphene-Based Gas/Vapor Sensors with Unique Properties and Potential Applications

Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects, etc.Herein, we summarize recent advantages in graphene preparation, sensor construction, and sensing properties of various graphene-based gas/vapor sensors, such as NH_3, NO_2, H_2, CO, SO_2, H_2S, as well as vapor of volatile organic compounds.The detection mechanisms pertaining to various gases are also discussed. In conclusion part, some existing problems which may hinder the sensor applications are presented. Several possible methods to solve these problems are proposed, for example, conceived solutions, hybrid nanostructures, multiple sensor arrays, and new recognition algorithm.

Ferroptosis-induced anticancer effect of resveratrol with a biomimetic nano-delivery system in colorectal cancer treatment

Ferroptosis is a novel form of programmed cell death impelled by iron-dependent lipid peroxidation,which may be a potential strategy for cancer therapy.Here we demonstrated for the first time that Resveratrol(RSV),a traditional Chinese medicine(TCM)chemical monomer,could effectually inhibit the growth of colon cancer cells through the ROS-dependent ferroptosis pathway.Mechanistically,RSV evoked the increase of reactive oxygen species and lipid peroxidation in colorectal cancer cells,and eventually lead to ferroptosis.Furthermore,RSV could promote ferroptosis by downregulating the expression of the channel protein solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4).To improve the delivery efficiency of RSV,a biomimetic nanocarrier was developed by coating RSV-loaded poly(ε-caprolactone)-poly(ethylene glycol)(PCL-PEG)nanoparticles with erythrocyte membrane(RSV-NPs@RBCm).The RSV-NPs@RBCm provide the possibility to escape macrophage phagocytosis and have a long circulation effect.In addition,when coupled with a tumor-penetrating peptide iRGD,which could trigger enhanced tissue penetration tumor-specifically,the delivery of RSV-NPs@RBCm into tumors would be significantly improved results from the in vivo study demonstrated an excellent treatment efficacy for CRC.Altogether,our study highlighted the therapeutic potential of RSV as a ferroptosis-inducing anticancer agent and when loaded into a biomimetic nanoplatform,it might pave the way for the application of RSV loaded nanosystems for colorectal cancer treatment.

Insights into triterpene synthesis and unsaturated fatty-acid accumulation provided by chromosomallevel genome analysis of Akebia trifoliata subsp . australis

Akebia trifoliata subsp.australis is a well-known medicinal and potential woody oil plant in China.The limited genetic information available for A.trifoliata subsp.australis has hindered its exploitation.Here,a high-quality chromosomelevel genome sequence of A.trifoliata subsp.australis is reported.The de novo genome assembly of 682.14 Mb was generated with a scaffold N50 of 43.11 Mb.The genome includes 25,598 protein-coding genes,and 71.18%(485.55 Mb)of the assembled sequences were identi fi ed as repetitive sequences.An ongoing massive burst of long terminal repeat(LTR)insertions,which occurred~1.0 million years ago,has contributed a large proportion of LTRs in the genome of A.trifoliata subsp.australis.Phylogenetic analysis shows that A.trifoliata subsp.australis is closely related to Aquilegia coerulea and forms a clade with Papaver somniferum and Nelumbo nucifera,which supports the well-established hypothesis of a close relationship between basal eudicot species.The expansion of UDP-glucoronosyl and UDP-glucosyl transferase gene families and fi-amyrin synthase-like genes and the exclusive contraction of terpene synthase gene families may be responsible for the abundant oleanane-type triterpenoids in A.trifoliata subsp.australis.Furthermore,the acyl-ACP desaturase gene family,including 12 stearoyl-acyl-carrier protein desaturase(SAD)genes,has expanded exclusively.A combined transcriptome and fatty-acid analysis of seeds at fi ve developmental stages revealed that homologs of SADs,acyl-lipid desaturase omega fatty acid desaturases(FADs),and oleosins were highly expressed,consistent with the rapid increase in the content of fatty acids,especially unsaturated fatty acids.The genomic sequences of A.trifoliata subsp.australis will be a valuable resource for comparative genomic analyses and molecular breeding.

Investigation on Thermal Insulation and Mechanical Strength of Lightweight Aggregate Concrete and Porous Mortar in Cold Regions

Thermal insulation is an important indicator to evaluate the construction material in cold region engineering.As we know,adding the industrial waste as lightweight aggregate or creating the pore inside the cement-based composite could make the texture loose,and the thermal insulating capacity of the material would be improved with this texture.Using these methods,the industrial by-product and engineering waste could be cycled in an efficient way.Moreover,after service the fragmented cement composites paste could be used as aggregate in the thermal insulating concrete again.While the porous texture is not favorable for the mechanical strength and long-term durability in a cold environment.To balance the above three requirements from two opposite directions,different processing methods were applied to create the thermal insulation concrete/mortar.Firstly,the organic/inorganic lightweight aggregate,including the Expanded Polystyrene(EPS),Expanded Perlite(EP),and Ceramsite(CRMST)particles,were applied to create the Lightweight Aggregate Concrete(LWAC).As the comparative tests,the expanded Superabsorbent Polymer(SAP)hydrogel and Air-Entraining Agent(AEA)were also introduced to create the porous mortar.The above concrete/mortar was tested in the normal state and under the Freeze-Thaw cycle to explore the engineering performance in cold regions.During the experimenting process,the thermal insulation,mechanical strength,and frost resistance of these cement-based composites were investigated,and an optimal thermal insulation concrete/mortar was determined.

Analysis on the Breeding and Major Traits of Wide-adaptability Indica CMS Line Yungu 3A

Breeding sterile lines is the key to the development of hybrid rice with wide adaptability. However, at present, few wide-adaptability sterile lines have been applied in production practice. In this study, Yungu 3A, a new WA-type Indica CMS line with good grain quality, was developed by hybridization between Yunfeng 66A with wide adaptability as female parent and F1 plants of Yunfeng 66B/D62B as male parent and continuous backcrossing. According to the results, the finally obtained lndica CMS line Yungu 3A has good plant type and leaf shape, strong tillering ability, excellent flowering habit, stable and complete male sterility with the sterile plant rate and pollen sterility rate of 100%, strong combining ability, high outcrossing rate, low sensitivity to light and temperature, and strong disease resistance, which was approved by Yunnan Provincial Crop Variety Appraisal Committee in 2013. Yungu 3A is conducive to the development of new hybrid rice combinations with good quality and wide adaptability, exhibiting a promising prospect of application.

Investigation and Analysis of Harmful Organisms Intercepted from Imported Seeds and Seedlings during 2011-2014

In this study,records published by General Administration of Quality Supervision,Inspection and Quarantine of China and related literature on harmful organisms intercepted from imported seeds and seedlings during 2011-2014 were investigated and analyzed.The results showed that the species and amount of harmful organisms intercepted from imported seeds and seedlings increased gradually during 2011-2014,which posed a realistic or potential threat to agriculture production in China.Based on the present situation,corresponding suggestions and countermeasures were proposed：1 strengthening the study on rapid detection technology of harmful organisms;2 improving the ability of animal and plant quarantine in China.

添加剂及其含量对交联聚乙烯高压电缆绝缘材料性能影响

为优化高压电缆交联聚乙烯(XLPE)绝缘材料配方,采用凝胶萃取、热延伸、转矩流变仪和失重法研究材料交联特性,采用红外光谱表征XLPE热氧老化特性,并测试了XLPE的力学性能和电学性能。结果表明,随交联剂过氧化二异丙苯(DCP)含量增大,XLPE凝胶含量及交联速率增大、力学性能变化较小、交流击穿强度的温度敏感性降低。优先考虑交联特性,确定DCP含量为1.8 phr。随抗氧剂含量增加,XLPE交联度降低、热延伸率稍有提高。相比单独使用0.3 phr抗氧剂300的XLPE,抗氧剂1010和1035各以0.15 phr复配使用可发生协同作用,从而更显著地抑制XLPE中羰基的形成和热氧老化,还可以在不降低交联度的前提下,改善XLPE抗焦烧性,避免预交联对XLPE性能的影响,且该材料具有更优的击穿强度温度特性和更低的介电损耗。

氨基酸衍生物结合试验在化妆品检测中的应用

以OECD指南为基础,在实验室建立氨基酸衍生物结合试验(ADRA)方法并进行实验室内验证,同时评估该方法对测试化妆品配方致敏反应的可能性。依据OECD 442C指南,将受试物(包括化学品和化妆水配方)分别与半胱氨酸衍生物和赖氨酸衍生物以50∶1的比例避光孵育24 h,采用高效液相色谱法分析两种氨基酸衍生物的消耗,计算氨基酸衍生物消耗率并依据ADRA预测模型对受试物致敏性进行判定。同样条件下使用商业化ADRA试剂盒按照操作规程检测相同受试物的致敏性。由试验结果可知,实验室建立的ADRA方法可以准确区分13种化学品的致敏性,检测结果与OECD442C指南及文献中小鼠淋巴结试验(LLNA)结果一致,也与商业化试剂盒检测结果一致;ADRA对5种化妆水配方检测结果显示4种为致敏物、1种为非致敏物。

Subsurface deformation mechanism and the interplay relationship between strength–ductility and fretting wear resistance during fretting of a high-strength titanium alloy

Fretting wear damage of high-strength titanium fasteners has caused a large number of disastrous accidents.Traditionally,it is believed that both high strength and excellent ductility can reduce fretting wear damage.However,whether strength and ductility are contradictory or not and their appropriate matching strategy under the external applied normal stress(Fw)are still confusing problems.Here,by analyzing the subsurface-microstructure deformation mechanism of several samples containing variousαprecipitate features,for the first time,we design strategies to improve fretting damage resistance under different matching relation between Fw and the tensile strength of materials(Rm).It is found that when Fw is greater than Rm or Fw is nearly equivalent to Rm,the deformation mechanism mainly manifests as serious grain fragmentation ofβandαGB constituents.Homogeneous deformation in large areas only reduces damage to a limited extent.It is crucial to improve the strength to resist cracking and wear,but it is of little significance to improve the ductility.However,when Fw is far less than Rm,coordinated deformation ability reflected by ductility plays a more important role.The deformation mechanism mainly manifests as localized deformation ofβandαGB constituents(kinking induced by twinning and spheroidizing).A unique composite structure of nano-grained/lamellar layer and localized deformation transition layer reduces fretting damage by five times compared with a single nanograined layer.Only when the strength is great enough,improving the plasticity can reduce wear.This study can provide a principle for designing fretting damage resistant alloys.

A Nitsche-Based Element-Free Galerkin Method for Semilinear Elliptic Problems

A Nitsche-based element-free Galerkin(EFG)method for solving semilinear elliptic problems is developed and analyzed in this paper.The existence and uniqueness of the weak solution for semilinear elliptic problems are proved based on a condition that the nonlinear term is an increasing Lipschitz continuous function of the unknown function.A simple iterative scheme is used to deal with the nonlinear integral term.We proved the existence,uniqueness and convergence of the weak solution sequence for continuous level of the simple iterative scheme.A commonly used assumption for approximate space,sometimes called inverse assumption,is proved.Optimal order error estimates in L 2 and H1 norms are proved for the linear and semilinear elliptic problems.In the actual numerical calculation,the characteristic distance h does not appear explicitly in the parameterβintroduced by the Nitsche method.The theoretical results are confirmed numerically。

原子力显微镜在弹性体材料微观结构表征中的应用进展

原子力显微镜(AFM)技术作为一种材料微观结构的表征技术,被广泛应用于弹性体材料微观结构的研究。文中主要综述了原子力显微镜的工作原理和工作模式,通过实例系统介绍了近年来AFM应用于弹性体复合材料界面结构、填料分散性以及拉伸过程的研究进展,总结了相关的研究方法和研究成果。最后,对原子力显微镜在弹性体复合材料微观结构领域的研究前景作出了展望,为今后弹性体复合材料微观结构的定量表征提供了理论参考。

钢桥面环氧沥青混合料铺装层养护修补技术研究

基于荆岳大桥钢桥面环氧沥青混合料铺装养护的工程实践,总结铺装使用状况、病害类型与成因分析以及养护维修技术,重点对裂缝和坑槽以及大面积维修三类主要病害的维修方案、施工工艺与修复效果进行阐述。结合荆越大桥钢桥面铺装养护工作,对环氧沥青混凝土铺装病害与成因进行论述,介绍了环氧沥青混凝土铺装局部维修技术,为钢桥面环氧沥青混合料铺装养护维修提供参考。

Effects of water-based binders on electrochemical performance of manganese dioxide cathode in mild aqueous zinc batteries

In the majority of rechargeable batteries including lithium-ion batteries,polyvinylidene fluoride(PVdF)binders are the most commonly used binder for both anode and cathode.However,using PVdF binder requires the organic solvent of N-methyl-2-pyrrolidone which is expensive,volatile,combustible,toxic,and has poor recyclability.Therefore,switching to aqueous electrode processing routes with non-toxic binders would provide a great leap forward towards the realization of ideally fully sustainable and environmentally friendly electrochemical energy storage devices.Various water-soluble binders(aqueous binders)were characterized and compared to the performance of conventional PVdF.Our study demonstrates that the electrochemical performance of Zn/MnO_(2) aqueous batteries is significantly improved by using sodium carboxymethyl cellulose(CMC)binder.In addition,CMC binders offer desirable adhesion,good wettability,homogeneous material distribution,and strong chemical stability at certain pH levels(3.5-5)without any decomposition for long-cycle life.

Geometric effect promoted hydrotalcites catalysts towards aldol condensation reaction

In solid basic catalysis field,how to achieve optimized activity and desired stability through elaborate control over basic site properties remains a challenge.In this work,taking advantage of the structure memory effect of layered double hydroxides(LDHs),rehydrated Ca4 Al1-x Gax-LDHs and Ca4 Al1-x Inx-LDHs catalysts were prepared and applied in aldol condensation reaction that isobutyraldehyde(IBD)reacts with formaldehyde(FA)to obtain hydroxypivalaldehyde(HPA).Notably,the resulting re-Ca4 Al0.90Ga0.10-LDHs exhibits an extraordinarily-high catalytic activity(HPA yield:72%),which is to our best knowledge the highest level in this reaction.The weak Br?nsted basic site,7-coordinated Ca-OH group,which serves as an active site,catalyzes the condensation process and promotes the product desorption.Studies on structure-property correlations demonstrate that Ga as a structural promoter induces a moderate expansion of the laminate lattice,which results in a significant increase in the concentration of weak basic sites in re-Ca4Al0.90Ga0.10-LDHs,accounting for its high catalytic activity.This work illuminates that geometric structure of basic active sites can be tuned via introducing catalyst additive,which leads to a largely improved performance of hydrotalcite solid basic catalysts towards aldol condensation reaction.

Elemental and proximate analysis of coal by x-ray fluorescence assisted laser-induced breakdown spectroscopy

Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.

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。

Allogeneic hematopoietic stem cell transplantation for patients with acute leukemia

Objective： The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation （HSCT） for acute leukemia （AL） and analyze the factors affecting the prognosis of these patients. Methods： The clinical and follow-up data of 93 AL patients （median age, 30 years） undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined. Results： Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease （aGvHD） and extensive chronic GvHD （cGvHD） were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality （TRM） and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival （OS） and disease-free survival （DFS） of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse （all P〈0.05）. Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis （all P〈0.05）. Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes （all P〈0.05）. Conclusions： Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD are independent risk factors affecting the prognosis.

Multi-Object Tracking with Micro Aerial Vehicle

A simple yet efficient tracking framework is proposed for real-time multi-object tracking with micro aerial vehicles(MAVs). It's basic missions for MAVs to detect specific targets and then track them automatically. In our method, candidate regions are generated using the salient detection in each frame and then classified by an eural network. A kernelized correlation filter(KCF) is employed to track each target until it disappears or the peak-sidelobe ratio is lower than a threshold. Besides, we define the birth and death of each tracker for the targets. The tracker is recycled if its target disappears and can be assigned to a new target. The algorithm is evaluated on the PAFISS and UAV123 datasets. The results show a good performance on both the tracking accuracy and speed.