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Diffusion mechanism of immiscible Fe-Mg system induced by high-density defects at the steel/Mg composite interface

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Journal of Materials Science & Technology 2023年第13期144卷 150-160页

作者： Yanlan Sun Xuefeng Liu Wenjing Wang Yaohua Yang Weiliang Zhang Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China Key Laboratory for Advanced Materials Processing of Ministry of Education University of Science and Technology BeijingBeijing 100083China

Due to positive mixing heat between Fe and Mg,it is difficult to diffuse for Fe-Mg at the interface of steel/Mg laminated composites,resulting in the inability to achieve high-strength metallurgical bonding.In this paper,20#steel/Mg laminated composites were prepared by large deformation rolling and subse-quent diffusion heat treatment process.The interfacial bonding strength was improved by constructing high-density crystal defects at the interface to promote element diffusion.The mechanisms of interface morphology evolution and element diffusion were analyzed by finite element simulation and theoretical calculation.The results show after diffusion heat treatment,the bond strength of the large deformation rolled interface was increased from 14 to 30 MPa.Fe-Mg transition layer with about 80 nm thickness as well as high-density vacancies,dislocations and grain boundaries were formed in the large deforma-tion rolled interface region.During diffusion heat treatment,Mg elements diffused into grain interior and grain boundary regions of 20#steel under the effect of heat-force coupling,and the thickness of Fe-Mg transition layer increased to 150 nm,forming an Fe-based supersaturated solid solution.The in-terface with high-density defects constituted a non-equilibrium interface.The 20#steel internal energy in the non-equilibrium interface is able to overcome positive mixing heat of immiscible Fe-Mg system and provide the driving force for Mg elements diffusion.Promoting elemental diffusion by constructing high-density defects can be a new concept to achieve metallurgical bonding at the interface of immiscible metal laminated composites.

关键词： Steel/Mg composite interface Immiscible Fe-Mg system Non-equilibrium interface Diffusion mechanism

Bacillus velezensis JK-XZ8 prevents and controls crown gall disease on Prunus subhirtella by colonizing and inducing resistance

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Journal of Forestry Research 2022年第3期33卷 1019-1031页

作者： Xitang zhang weiliang Kong Xiaoqin Wu Jianren Ye Co-Innovation Center for Sustainable Forestry in Southern China College of ForestryNanjing Forestry UniversityNanjing210037JiangsuPeople’s Republic of China Jiangsu Key Laboratory for Prevention and Management of Invasive Species Nanjing Forestry UniversityNanjing210037JiangsuPeople’s Republic of China

Crown gall of Prunus subhirtella Miq., flowering cherry, is a soil-borne bacterial disease caused by Agrobacterium tumefaciens Smith & Townsend and has caused serious damage to the species in recent years in China. In this study, the colonization of sapling roots, the biocontrol efficacy, the expression of defense-related genes and the enzyme activity in roots of P. subhirtella inoculated with the Bacillus velezensis JK-XZ8 against A. tumefaciens were determined under greenhouse conditions. The results showed that the JK-XZ8 strain colonized in the rhizosphere and root surfaces of the saplings. Sole application of the strain increased activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) without affecting superoxide dismutase (SOD). SOD and PPO activities increased in the prevention group, and the activity of PAL increased in both the prevention and cure groups. The expression of the defense-related genes PAL and PR-1 of salicylic acid pathway in roots increased in both the prevention and cure groups. Simultaneously on day 3, the expression of both COI and MYC2 genes of the jasmonic acid pathway significantly increased in the two groups. The incidence of crown gall in the prevention and the cure groups were 48.1% and 66.7%, respectively, significantly lower compared to the pathogens alone (87.5%). This study showed that the application of the JK-XZ8 strain reduced the incidence of crown gall in P. subhirtella saplings in the two groups, and the prevention group had better control efficacy. In addition, the JK-XZ8 strain protects against crown gall by developing induced systemic resistance and systemic acquired resistance in the roots of the cherry saplings.

关键词： Bacillus velezensis Prunus subhirtella Crown gall Plant-induced resistance Control effect

Responsive and self-healing structural color supramolecular hydrogel patch for diabetic wound treatment

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Bioactive Materials 2022年第9期7卷 194-202页

作者： Canwen Chen Yu Wang Han zhang Hui zhang weiliang Dong Weijian Sun Yuanjin Zhao Department of Rheumatology and Immunology Institute of Translational MedicineThe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing210008China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China State Key Laboratory of Materials-Oriented Chemical Engineering College of Biotechnology and Pharmaceutical EngineeringNanjing Tech UniversityNanjing211800China Department of Gastrointestinal Surgery The Second Affiliated Hospital of Wenzhou Medical UniversityWenzhou325027China

The treatment of diabetic wounds remains a great challenge for medical community.Here,we present a novel structural color supramolecular hydrogel patch for diabetic wound treatment.This hydrogel patch was created by using N-acryloyl glycinamide(NAGA)and 1-vinyl-1,2,4-triazole(VTZ)mixed supramolecular hydrogel as the inverse opal scaffold,and temperature responsive poly(N-isopropylacrylamide)(PNIPAM)hydrogel loaded with vascular endothelial cell growth factor(VEGF)as a filler.Supramolecular hydrogel renders hydrogel patch with superior mechanical properties,in which NAGA and VTZ also provide self-healing and antibacterial properties,respectively.Besides,as the existence of PNIPAM,the hydrogel patch was endowed with thermal-responsiveness property,which could release actives in response to temperature stimulus.Given these excellent performances,we have demonstrated that the supramolecular hydrogel patch could significantly enhance the wound healing process in diabetes rats by downregulating the expression of inflammatory factors,promoting collagen deposition and angiogenesis.Attractively,due to responsive optical property of inverse opal scaffold,the hydrogel patch could display color-sensing behavior that was suitable for the wound monitoring and management as well as guidance of clinical treatment.These distinctive features indicate that the presented hydrogel patches have huge potential values in biomedical fields.

关键词： Bioinspired Structural color Responsive Patch Wound healing

Uncertainty analysis and robust design optimization for the heat-assisted bending of high-strength titanium tube

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Science China(Technological Sciences) 2021年第10期64卷 2174-2185页

作者： zhang Zhao YANG JingChao HUANG weiliang MA Jun LI Heng Taicang Yangtze River Delta Research Institute Northwestern Polytechnical UniversityTaicang 215400China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Heat-assisted rotary draw bending(HRDB)is a promising technique for manufacturing difficult-to-form tubular components comprising high-strength titanium tubes(HSTTs)with small bending radii.However,as a multidie constrained and thermomechanical coupled process with many uncertainty factors,a high risk of several defects,such as cross-section distortion,over wall thinning,or even cracking,is present.Achieving the robust design optimization(RDO)of complex forming processes remains a nontrivial and challenging scientific issue.Herein,considering a high-strength Ti-3Al-2.5V titanium alloy tube as a case material,the five significant uncertainty factors in HRDB,i.e.,temperature distribution,tube geometrical characteristics,tube material parameters,tube/tool friction,and boost velocity had been analyzed.Subsequently,considering the preheating and HRDB of HSTT,a whole-process thermomechanical three-dimensional finite element model was established and validated for virtual experiments.Further,considering the maximum section distortion Q and maximum wall-thickness thinning t as the optimization objectives and the mean and variance of material and forming parameters,an RDO model was established.Finally,the Pareto optimal solutions were obtained using the nondominated sorting genetic algorithm II,and a minimum distance selection method was employed to obtain the satisfactory solution.Results show that the optimized solutions considering the uncertainty factors reduce the maximum section distortion rate of HSTT after bending by 38.1%and the maximum wallthickness thinning rate by 27.8%.

关键词： robust design optimization uncertainty factors heat-assisted bending high-strength titanium tube

Development of a masticatory robot using a novel cable-driven linear actuator with bidirectional motion

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Frontiers of Mechanical Engineering 2022年第4期17卷 53-65页

作者： Haiying WEN Jianxiong ZHU Hui zhang Min DAI Bin LI Zhisheng zhang weiliang XU Ming CONG School of Mechanical Engineering Southeast UniversityNanjing 211189China Engineering Research Center of New Light Sources Technology and Equipment Ministry of EducationNanjing 210009China Department of Stomatology Zhongda Hospital Affiliated to Southeast UniversityNanjing 210009China Department of Mechanical&Mechatronics Engineering The University of AucklandAuckland 1142New Zealand School of Mechanical Engineering Dalian University of TechnologyDalian 116024China

Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses.A cable-driven linear actuator(CDLA)capable of bidirectional motion is proposed in this study to design a masticatory robot that can achieve increasingly human-like chewing motion.The CDLA presents remarkable advantages,such as lightweight and high stiffness structure,in using cable amplification and pulley systems.This work also exploits the proposed CDLA and designs a masticatory robot called Southeast University masticatory robot(SMAR)to solve existing problems,such as bulky driving linkage and position change of the muscle’s origin.Stiffness analysis and performance experiment validate the CDLA’s efficiency,with its stiffness reaching 1379.6 N/mm(number of cable parts n=4),which is 21.4 times the input wire stiffness.Accordingly,the CDLA’s force transmission efficiencies in two directions are 84.5%and 85.9%.Chewing experiments are carried out on the developed masticatory robot to verify whether the CDLA can help SMAR achieve a natural human-like chewing motion and sufficient chewing forces for potential applications in performance tests of dental materials or prostheses.

关键词： masticatory robot cable-driven linear actuator parallel robot stiffness analysis

Defect promoted photothermoelectric effect in densely aligned ZnO nanorod arrays for self-powered position-sensitive photodetection

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Journal of Materiomics 2022年第3期8卷 693-701页

作者： Xinxin Du weiliang Tian Ziqi zhang Bin Hui Jiahui Pan Jianhua Sun Kewei zhang State Key Laboratory of Bio-Fibers and Eco-Textiles Collaborative Innovation Center for Marine Biomass FibersMaterials and Textiles of Shandong ProvinceCollege of Materials Science and EngineeringInstitute of Marine Biobased MaterialsQingdao UniversityQingdao266071China Key Laboratory of Chemical Engineering in South Xinjiang College of Life ScienceTarim UniversityAlar843300China Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology Guangxi UniversityNanning530004China

Sustainable light energy from ambient environment has attracted particular attention to meet the evergrowing need of small-scale electronics.The modulation of intercorrelated thermal and electronic transport is one of the crucial aspects for reliable photothermoelectric electronics.Herein,a defectpromoted photothermoelectric effect is demonstrated in densely aligned ZnO nanorod array with rich lattice defects.The defect-rich ZnO device delivers high electrical conductivity and large Seebeck coefficient to enable significant improvement of photothermoelectric energy conversion and self-powered photodetection.The position sensitivity reaches approximately 0.19 mV mm^(-1),and the temperature gradient induced electric field makes up for the suppression in the photothermoelectric process.The synergism between intrinsic defects and extra temperature field plays an important role in promoting the photothermoelectric properties of dense ZnO nanorod array.This study is interesting for interpreting the thermo-phototronic phenomena as well as demonstrating the possibility of defect engineering and phonon engineering to enable highly efficient light energy scavenging and self-powered photodetection.

关键词： Defect-rich ZnO Photodetectors Light energy Photothermoelectric Self-powered

Addressing the Chengjiang conundrum: A palaeoecological view on the rarity of hurdiid radiodonts in this most diverse early Cambrian Lagerstatte

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Geoscience Frontiers 2022年第6期13卷 1-15页

作者： Yu Wu Stephen Pates Jiaxin Ma weiliang Lin Yuheng Wu Xingliang zhang Dongjing Fu State Key Laboratory of Continental Dynamics Shaanxi Key Laboratory of Early Life and Environmentsand Department of GeologyNorthwest UniversityXi’an 710069China Department of Zoology University of CambridgeDowning StreetCambridge CB23EJUnited Kingdom

Over one hundred arthropod fossil species have been described from the famous Chengjiang Lagerst?tte(South China, Cambrian Stage 3, ca. 518 Ma) including a diverse assemblage of radiodonts–a group containing Anomalocaris and its relatives. These iconic stem-group euarthropods include some of the largest animals of the time, and some are known from hundreds of specimens. A longstanding conundrum has been the rarity or absence of hurdiids from Cambrian Series 2 Lagerst?tten like Chengjiang. This is because radiodonts are generally common in such deposits and the oldest radiodont ever discovered is a hurdiid. Furthermore, this family displays the widest geographic and temporal ranges of all radiodont families, and the highest diversity. Here we document the first hurdiid frontal appendages from Chengjiang, which display unique features within the family and may provide insights for understanding the character evolution of hurdiid appendages. The palaeoenvironmental distribution of hurdiids suggests that the rarity of hurdiids in Chengjiang may be due to a preference for deeper water environments,and the later success of this family from the Wuliuan onwards may relate to their ability to tolerate cooler water temperatures than other radiodont families. The palaeogeographical, palaeoenvironmental, and stratigraphical patterns observed in hurdiids maybe caused in part by the limited distributions of Konservat-Lagerst?tten in the Cambrian as well.

关键词： Radiodonta Hurdiidae Panarthropoda Palaeobiogeography Palaeoenvironment Chengjiang Lagerstatte

Optimal design of a linkage-cam mechanism-based redundantly actuated parallel manipulator

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Frontiers of Mechanical Engineering 2021年第3期16卷 451-467页

作者： Haiying WEN Zhisheng zhang Min DAI Ming CONG weiliang XU School of Mechanical Engineering Southeast UniversityNanjing 211189China School of Mechanical Engineering Dalian University of TechnologyDalian 116024China Department of Mechanical Engineering The University of AucklandAuckland 1142New Zealand

A redundantly actuated parallel manipulator(RAPM)with mixed translational and rotational degrees of freedom(DOFs)is challenged for its dimensionally homogeneous Jacobian modeling and optimal design of architecture.In this paper,a means to achieve redundant actuation by adding kinematic constraints is introduced,which reduces the DOFs of the end-effector(EE).A generic dimensionally homogeneous Jacobian is developed for this type of RAPMs,which maps the generalized velocities of three points on the EE to the joint velocities.A new optimization algorithm derived from this dimension-ally homogeneous Jacobian is proposed for the optimal design of this type of RAPMs.As an example,this paper presents a spatial RAPM involving linkages and cam mechanisms.This RAPM has 4 DOFs and 6 translational actuations.The linkage lengths and the position of the universal joints of the RAPM are optimized based on the dimensionally homogeneous Jacobian.

关键词： redundant actuation parallel manipulator linkage-cam mechanism Jacobian optimal design

Higher Speed Passive Optical Networks for Low Latency Services

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ZTE Communications 2021年第2期19卷 61-66页

作者： zhang weiliang YUAN Liquan Wireline Product Planning Department ZTE CorporationShanghai 201203China

Latency sensitive services have attracted much attention lately and imposedstringent requirements on the access network design. Passive optical networks (PONs) providea potential long-term solution for the underlying transport network supporting theseservices. This paper discusses latency limitations in PON and recent progress in PONstandardization to improve latency. Experimental results of a low latency PON system arepresented as a proof of concept.

关键词： passive optical networks time-division multiple access wavelength-division multiple access low latency