终端区空中交通管制运行品质综合评价

为定量评价繁忙终端区空中交通管制运行品质,以成都终端区为研究对象,针对单跑道终端区,建立了包括管制业务量、安全性能、效率性能、工作负荷及交通拥挤度的管制运行品质定量评价指标体系.根据专家意见选取20个相对独立的指标,给出了基于主成分分析法的综合评价方法.采集覆盖一周每日繁忙时段10:00～22:00的84个样本,得到各时段的管制运行品质综合评价结果.经K-均值聚类分析及实际运行表明,本文方法可行,评价结果与实际情况相符.评价结论为终端区的运行策略优化提供了依据.     

Recycling of aluminum from fibre metal laminates

Recycling of aluminum alloy scrap obtained from delaminated fibre metal laminates (FMLs) was studied through high temperature refining in the presence of a salt flux. The aluminum alloy scrap contains approximately mass fraction w(Cu) = 4.4%, w(Mg) = 1.1% and w(Mn) = 0.6% (2024 aluminum alloy). The main objective of this research is to obtain a high metal yield, while maintaining its original alloy compositions. The work focuses on the metal yield and quality of recycled Al alloy under different refining conditions. The NaCl-KCl salt system was selected as the major components of flux in the Al alloy recycling. Two different flux compositions were employed at NaCl to KCl mass ratios of 44:56 and 70:30 respectively, based on either the eutectic composition, or the European preference. Different additives were introduced into the NaCl-KCl system to study the effect of flux component on recycling result. Although burning and oxidation loss of the alloying elements during re-melting and refining take place as the drawbacks of conventional refining process, the problems can be solved to a large extent by using an appropriate salt flux. Experimental results indicate that Mg in the alloy gets lost when adding cryolite in the NaCl-KCl salt system, though the metal yield can reach as high as 98%. However, by adding w(MgF₂) = 5% into the NaCl-KCl salt system (instead of using cryolite) all alloying elements were well controlled to its original composition with a metal yield of almost 98%.     

Microstructures and mechanical properties of various Mg-Li wrought alloys

Three kinds of ultra-light Mg-Li wrought alloys,Mg-5.5Li-3Al-1Zn-1Ce,Mg-7.0Li-3Al-1Zn-1Ce and Mg-10.5Li-3Al-1Zn-1Ce,were prepared by vacuum induction melting furnace;then the alloys were extruded and rolled.The microstructures and properties of these alloys were studied.The results indicate that the Mg-5.5Li3Al-1Zn-1Ce alloy has the highest strength,the Mg-10.5Li-3Al-1Zn-1Ce alloy has maximum elongation,and the Mg-7.0Li-3Al-1Zn-1Ce alloy has good comprehensive performance.Rolling deformation can increase strength further after extrusion deformation.     

Microstructure and property of friction stir welding joint of 7075Al and AZ31BMg

Microstructure and forming quality of friction stir welding joints of 7075Al and AZ31BMg with different welding parameters were analyzed. The results show that, good welded joint is obtained when the rotating frequency is 13 r/s and the welding speed is 30 mm/min. An irregular area is formed in the welding center. Meanwhile, the river pattern and eddy-like distribution are found in the weld nugget zone. Besides, brittle intermetallic compounds Al₁₂Mg₁₇ and Al₃Mg₂ are found in the welded joint. They cause the increase of microhardness of welded joint. The maximum tension stress of welded joint is 112MPa.     

Ignition-proof properties of a high-strength Mg-Gd-Ag-Zr alloy

<正>A high-strength Mg-15.3Gd-l.8Ag-0.3Zr(GQ152K,mass fraction) alloy was prepared by conventional ingot metallurgy process.The solution and aging(denoted as T6) treated alloy exhibits remarkable mechanical properties with ultimate tensile strength of 421 MPa and tensile yield strength of 309MPa.It has higher igniting temperature of 1208 K.Moreover,it can stand against flame at 1203 K for over 6 min in vertical burning tests, and its flammabiUty behavior is very similar to that of 6101A1 alloy.Vertical burning tests appear to be able to directly study the flammability behavior of Mg alloys and it appears to be a good approach to study the flammability behavior of Mg alloys in an aircraft fire accident.     

珠海港在珠三角港口群中定位的SWOT分析

珠海港位于珠江口的西南部,是西江流域唯一的天然深水海港.珠三角港口群中,香港、广州、深圳三港已占主导优势,通过对珠三角地区港口群主要港口的比较分析,运用SWOT模型对珠海港在珠三角港口群中所面临的优势、劣势、机会和挑战分析,提出了珠海港在珠三角港口群中近期定位和长期定位.     

铜镁合金接触线低周疲劳分析

通过采用不同塑性应变幅控制,对冷拔铜镁合金接触线进行室温低周疲劳试验.结果表明,随着循环周次的增加,发生循环软化现象.应力降低速率随着应变的降低而减缓.通过Manson-coffin公式估算出接触线用铜镁合金的低周疲劳寿命,得出应变-寿命关系,并指过渡寿命NT所在应变范围.     

一种基于Hyper-V和WSFC集群的主机多路径网络存储架构方案

本文通过Hyper-V虚拟化、WSFC故障转移集群和主机多路径技术的整合,利用网络存储技术设计了一种网络存储架构解决方案.此方案能在一定程度上节约硬件资源部署成本、减少系统非计划停机时间、提高硬件资源利用率、避免主机单路径造成的硬件故障,同时增强IO数据传输效率,从而提高整个信息系统运行的可靠性、安全性、稳定性及可持续性.     

高速公路事故多发点鉴别及诱发因素识别

为了提高事故多发点鉴别的客观公正性及自动化识别水平,提出了在公路沿线上划分初始评估地点的动态聚类算法,建立了鉴别事故多发点的自组织神经网络模型,给出了基于离散多变量算法与概率分布相结合的事故多发点突出事故诱发因素识别过程. 方法应用结果表明,基于动态聚类的初始评估点划分方法能够客观地描述出事故点在公路沿线上的集中与分散状况,而神经网络鉴别模型能够对初始评估地点的安全状况进行自动分类且结果较合理. 在掌握了能够满足统计分析要求的事故样本点数量的基础上,能够应用突出事故诱发因素识别方法建立一套评估标准,并用来识别事故多发点的突出事故诱发因素.     

某甩挂运输半挂牵引车的轻量化设计

以节能减排为目的,以某甩挂运输牵引车为研究对象进行轻量化设计.采用盘式制动器、少片簧等新技术;针对轮辋、变速器壳体、油箱、散热器、接头等采用铝合金与尼龙等新材料;采用单层纵梁、短轴距等新结构以及轻量化驱动桥.最终,使该牵引车的整备质量降至8 200 kg以下.经过有限元分析、台架试验及整车可靠性试验,验证了所采用轻量化设计方案的可行性.