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泡沫铝复合结构的制备研究进展与展望

建筑结构 2024年第19期54卷 90-98,168页

作者：李爱群晁磊刘少波吴宜峰杨参天北京建筑大学土木与交通工程学院北京100044 东南大学土木工程学院南京210096

泡沫铝是一种含有大量孔洞的多功能多孔金属材料,具备减震吸能、电磁屏蔽、隔热、阻尼、降噪等特性。由于其力学性能和耐腐蚀性能较差,研究人员多以密实金属材料作为面板或外壁提升泡沫铝的综合性能。泡沫铝夹芯板结构和泡沫铝填充管结... 详细信息

泡沫铝是一种含有大量孔洞的多功能多孔金属材料,具备减震吸能、电磁屏蔽、隔热、阻尼、降噪等特性。由于其力学性能和耐腐蚀性能较差,研究人员多以密实金属材料作为面板或外壁提升泡沫铝的综合性能。泡沫铝夹芯板结构和泡沫铝填充管结构作为泡沫铝复合结构的两种形式,具有显著的吸能特性与结构强度。现如今,泡沫铝复合结构因生产效率低、产品尺寸小、界面结合强度差以及制备成本高等问题,其快速发展与行业推广受到了限制。首先综述了有关泡沫铝复合结构的制备方法,包括泡沫铝夹芯板结构的胶粘连接、螺栓连接、焊接连接及粉末冶金连接等方法,泡沫铝填充管结构的原位制备法和非原位制备法,并在此基础上介绍了泡沫铝复合结构的力学性能以及不同制备方法的局限性。最后,简要分析了泡沫铝复合结构在土木工程领域应用的可行性,并对其进行了总结与展望。

关键词：泡沫铝复合结构夹芯板结构填充管结构制备方法力学性能土木工程领域

An efficient trust negotiation strategy towards the resource-limited mobile commerce environment

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Frontiers of Computer Science 2016年第3期10卷 543-558页

作者： Bailing LIU Yanhui LI Bing ZENG chao lei School of Information Management Central China Normal University Wuhan 430079 China School of Software Engineering South China University of Technology Guangzhou 510006 China

Automated trust negotiation （ATN） offers an at- tractive means for trust establishments, which establishes mu- tual trust among strangers wishing to share resources or con- duct business, but it comes at the cost of non-trivial computa- tion and communication overheads. The deployment of ATN strategies on a resource-constrained mobile device may lead to user-obstructive latency for operations. In this paper, we propose a trust negotiation strategy called trust target Petri nets negotiation strategy （TPNNS）. It highly reduces the ne- gotiation latency in the mobile device compared with other negotiation strategies, since it considers all the alternative re- sponses at each step and chooses the best one. TPNNS sup- ports cycle avoidance and employs skipped TPN which is a new approach presented in this paper. What is more, it is complete and ensures no irrelevant credentials are disclosed during the trust negotiation.

关键词： automated trust negotiation mobile commerce,negotiation strategy Petri net

Adaptive finite element-element-free Galerkin coupling method for bulk metal forming processes

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 353-360页

作者： lei-chao LIU Xiang-huai DONG Cong-xin LI National Die and Mould CAD Engineering Research Center Shanghai Jiao Tong University Shanghai 200030 China

An adaptive finite element-element-free Galerkin (FE-EFG) coupling method is proposed and developed for the numerical simulation of bulk metal forming processes. This approach is able to adaptively convert distorted FE elements to EFG domain in analysis. A new scheme to implement adaptive conversion and coupling is presented. The coupling method takes both advantages of finite element method (FEM) and meshless methods. It is capable of handling large deformations with no need of remeshing procedures, while it is computationally more efficient than those full meshless methods. The effectiveness of the proposed method is demonstrated with the numerical simulations of the bulk metal forming processes including forging and extrusion.

关键词： Meshless method Adaptive coupling method Bulk metal forming Numerical simulation

Forming condition and control strategy of ferrite decarburization in 60Si2MnA spring steel wires for automotive suspensions

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 116-121页

作者： chao-lei Zhang Ya-zheng Liu Le-yu Zhou chao Jiang Jin-fu Xiao School of Materials Science and Engineering University of Science and Technology BeijingBeijing 10083China

The ferrite decarburization behavior of 60Si2MnA spring steel wires for automotive suspensions, including the forming condition and the influence of heating time and cooling rate after hot rolling, was investigated comprehensively. Also, a control strategy during the reheating process and cooling process after rolling was put forward to protect against ferrite decarburization. The results show that ferrite decarburization, which has the strong temperature dependence due to phase transformation, is produced between 675 and 875°C. The maximum depth is found at 750°C. Heating time and cooling rate after rolling have an important influence on decarburization. Reasonable preheating temperature in the billet reheating process and austenitizing temperature in the heat-treatment process are suggested to protect against ferrite decarburization.

关键词： spring steel decarburization phase transformations controlled cooling

Non-isothermal creep age forming of Al-Cu-Li alloy:Experiment and modelling

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Chinese Journal of Aeronautics 2023年第5期36卷 566-581页

作者： Changhui WU Heng LI Tianjun BIAN chao lei Liwen ZHANG State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China

Non-isothermal Creep Age Forming(CAF),including loading,heating,holding,cooling and springback stages,is an advanced forming technique for manufacturing high performance large integral panels at short production period and low ***,the creep deformation and aging precipitation during heating stage is often neglected in experiments and modeling,leading to low forming *** achieve shape forming and property tailoring simultaneously,a deep understanding of the non-isothermal creep aging behavior and the establishment of predictive models are urgently required.A new five-stage creep feature of Al-Cu-Li alloy during the non-isothermal creep aging is *** microstructural interactions between the dislocations,solute atoms,Guinier Preston zones(GP zones)and T1 precipitates are found to dominate the five-stage creep aging *** physical-based model considering temperature evolution history is established to describe the five-stage creep *** springback and yield strength of non-isothermal creep age formed plates with different thicknesses are predicted and compared by non-isothermal CAF experiments and corresponding *** CAF experiments show that the springback and yield strength of the non-isothermal creep age formed plate are 62.1%and 506 MPa,*** results are in good agreement with experimental *** proposed model broadens the application of traditional CAF models that mainly focus on isothermal conditions.

关键词： Al-Cu-Li alloy Creep aging forming Microstructures Springback Mechanical properties Thickness

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基于GIS的卷烟区域物流配送中心选址

烟草科技 2024年第4期57卷 91-99页

作者：钟宇黎栿釜雷超周明珠邢军邓琦董浩中国烟草总公司合肥设计院合肥市徽州大道1199号230041 国家烟草质量监督检验中心郑州高新技术产业开发区翠竹街6号450001

为科学合理地实现卷烟区域物流配送中心选址,基于GIS(Geographic Information System)技术以及空间地理信息和互联网数据集构建了区域物流选址模型,并以华东地区某省拟选址区域物流配送中心为对象进行验证,结果表明:①通过对空间地理信... 详细信息

为科学合理地实现卷烟区域物流配送中心选址,基于GIS(Geographic Information System)技术以及空间地理信息和互联网数据集构建了区域物流选址模型,并以华东地区某省拟选址区域物流配送中心为对象进行验证,结果表明:①通过对空间地理信息数据集和互联网数据集进行数据处理和分析,获取用于选址的评价因子,并通过图层叠加的方法获得备选地址。②通过可达性分析可以获得客户覆盖率,实现最佳地址选择;所选地区的最佳地址60 min客户覆盖率为50.17%,90 min客户覆盖率为80.50%,可满足烟草行业物流配送要求。该方法可为提升卷烟物流运营水平提供支持。

关键词：卷烟 GIS 区域物流配送中心选址可达性分析

Insecticidal activities of garlic substances against adults of grain moth, Sitotroga cerealella （Lepidoptera： Gelechiidae）

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Insect Science 2012年第2期19卷 205-212页

作者： Feng-Lian Yang Fen Zhu chao-Liang lei Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory Huazhong Agricultural UniversityWuhanChina

The angoumois grain moth, Sitotroga cerealella （Olivier）, is one of the most serious stored grain pests around the world. In attempts to reduce the losses caused by the moth and to suppress its populations, the fumigant activities, behavioral influence and ovipositional inhibition of garlic （Allium sativum） essential oil and its two major components, diallyl disulfide and diallyl trisulfide, were investigated against the adult grain moth. Their effects on reduction in survival of first instar larvae to adult emergence were also evaluated. Results showed that these three materials （garlic essential oil, diallyl disulfide and diallyl trisulfide） had significant fumigant activity with 50% lethal concentration values at 1.33, 0.99, and 1.02/zL/L air space, respectively; meanwhile, the three materials possessed high behavioral deterrent activities against adults in the Y-tube olfactometer. When applied to rice grains, these materials reduced adult longevity and inhibited oviposition, with ovipositional inhibition above 70% at a concentration of 1.5uL/25 g in either no-choice or two-choice tests. In short, the study showed that both diallyl disulfide and diallyl trisulfide, like garlic essential oil, acted as fitrnigants, produced behavioral deter- rence and inhibited oviposition against angoumois grain moth. Our work here indicates that diallyl disulfide and diallyl trisulfide may serve as potential alternatives for grain protectants since both of them can be prepared easily from readily available chemicals.

关键词： behavioral deterrence essential oil fumigant garlic oviposition inhibition,Sitotroga cerealella

Effects of Niobium and Vanadium on Hydrogen-Induced Delayed Fracture in High Strength Spring Steel

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Journal of Iron and Steel Research International 2011年第6期18卷 49-53页

作者： ZHANG chao-lei LIU Ya-zheng JIANG chao XIAO Jin fu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Influence of vanadium and/or niobium additions on delayed fracture behavior in high strength spring steel was studied by hydrogen permeation method and slow strain rate technique （8SRT）, and its mechanism was analyzed. The results show that apparent diffusion coefficient of hydrogen in microalloyed spring steels Nb-V-steel and Nb-steel is lower than that in non-microalloyed steel 60Si2MnA. Percentage of strength reduction in SSRT in air after precharged hydrogen of the microalloyed steels is smaller than that of 60Si2MnA. Addition of the microalloys changes the fracture characteristics. Thence, vanadium and/or niobium additions are a very effective and economy means to improve the hydrogen-induced delayed fracture resistance of high strength spring steel.

关键词： spring steel microalloy hydrogen-induced delayed fracture slow strain rate technique hydrogen permeation

Surface decarburization characteristics and relation between decarburized types and heating temperature of spring steel 60Si2MnA

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International Journal of Minerals,Metallurgy and Materials 2013年第8期20卷 720-724页

作者： chao-lei Zhang Le-yu Zhou Ya-zheng Liu School of Materials Science and Engineering University of Science and Technology Beijing

The characteristics of complete and partial decarburizations in spring steel 60Si2MnA were systematically investigated, including the microstructure, the hardness gradient, and the formation mechanism. The relation between decarburized types and heating temperature of the steel was comprehensively discussed. It is found that heating temper- ature has an important influence on the decarburized types. With the rise of heating temperature, the decarburized types change from no decarburization to complete decarburization, complete and partial decarburizations, partial decarburiza- tion, and no decarburization.

关键词： spring steel decarburization temperature microstructure hardness