加装印刷电路板的圆孔阵矩形机壳屏蔽效能

为评估矩形金属机壳抗外部电磁干扰的能力,建立加装印刷电路板(PCB)有圆孔孔阵矩形机壳的波导等效电路模型,导出其电场屏蔽效能的简洁表达式,提出一种简单高效的新方法,对于没有加装印刷电路板的机壳,该方法的简化结果与现有文献结果完全一致;对于加装PCB的机壳屏蔽效能,该方法计算结果与CST仿真结果良好吻合。结果表明:电场极化方向与孔阵长度方向平行,同其与孔阵长度方向垂直比较,前者屏蔽效能显著优于后者;所考虑的频率范围内,加装PCB可以显著提高机壳的屏蔽效能;正交排列孔阵的屏蔽效能优于交错排列孔阵的屏蔽效能;保持孔阵中孔数目不变,孔间距越大,屏蔽效能越高。     

船体与设备一体化抗冲击分析

从主从系统耦合振动理论出发,基于数值实验手段,分别以船用增压锅炉、齿轮箱为研究对象,设计多种冲击输入对非一体化与一体化抗冲击分析例证进行数值计算,并将计算结果进行对比。研究结果表明,非一体化抗冲击分析方法割裂了设备与船体结构之间的耦合效应,不能精确再现船用设备实船冲击环境,中远场水下爆炸时非一体化抗冲击分析得到的设备响应结果偏大,中近场时结果偏小。建议中近场水下爆炸时肋位跨度较大的船用大型设备抗冲击性能分析采用船体与设备一体化抗冲击分析方法,若条件所限尚无法进行一体化分析,则应对非一体化抗冲击分析结果进行修正。     

舰载光电设备的三防设计

防湿热、防霉菌、防盐雾的三防设计是舰载光电设备设计的重要任务之一。针对舰载光电设备的三防问题展开研究,对光学镜头、机械结构和电子组件分别进行了相应的三防设计,具体包括材料的应用、结构形式的优化及防护工艺的合理选择等措施,所采取的三防设计和措施在恶劣的海洋环境下进行了多年的实践验证,结果表明:所采取的设计方法和措施能够保证舰载光电设备具有良好的三防性能,可以在恶劣的海洋环境下长期稳定工作。     

装备维修器材生产路径双目标问题优化决策方法研究

在装备维修器材供应保障中,针对精确保障背景下部队用户对器材保障精度的要求,构建了最小化总成本和最大化订单精准执行率的双目标优化决策模型。在ε-约束法框架内,开发可生成近似Pareto前沿的两阶迭代启发式算法,并采用模糊逻辑决策法选择符合决策者偏好的折中最优解。随机实例测试结果表明所提出的模型和算法可以很好地应用在双目标优化问题的研究中,并在求解不同规模实例时表现出优异的性能。     

The mathematical modelling of a production scale sequential continuous chromatographic refiner unit

Summary A plate to plate mathematical model of a sequential gas-liquid chromatographic separator used for the continuous separation of volatile organic mixtures has been extended to include theoretically determined temperature, pressure and concentration effects. A comparison has been made of predicted values with experimental results obtained on a 12 column (7.6 cm o.d. ×61 cm) sequential continuous chromatograph when separating an equivolume mixture of Arklone P-Genklene P at feed rates of up to 1400 cm³ hr^–1.     

Mass and heat transfer effects in continuous production scale gas-liquid chromatographic equipment

Summary A study has been made of the temperature and related solute concentrations in a 12 column (7.6 cm OD×61 cm) sequential continuous chromatograph at feed rates of up to 1400 cm³hr^–1 of Arklone P-Genklene P. Moving the feed point from the middle of a column to the end cone was found to be particularly beneficial. Besides increasing throughput it enabled the system Arklone P and dichloromethane (separation factor 1.17) to be separated, not previously possible with a central feed point.     

高新装备列装初期军方独立保障能力评估方法研究

针对军民融合模式下高新装备列装初期维修任务划分不科学、军地双方责任不明确等问题,提出了装备列装初期对军方独立保障能力进行评估的思想.在构建了高新装备列装初期基层级独立保障能力评估指标体系的基础上,为解决该时期基础数据不充足、评估人为因素过大等问题,建立了基于灰色-模糊的军方独立保障能力评估模型.以某式自行加榴炮列装初期军方独立保障能力评估为例对模型进行了验证.以期实现军民融合维修保障决策由定性分析向定量决策的转交.     

交通运输设备制造业能源消耗效率的投入产出分析

基于投入产出模型来研究中国交通运输设备制造业的能源消耗效率.首先构造了一个引入能源消耗的投入产出模型.然后利用该投入产出模型对中国交通运输设备制造业的能源消耗效率进行了实证分析,结果表明:1995~2002年间中国交通运输设备制造业的能源直接消耗效率不断提高;1997年比1992年的能源完全消耗效率也明显提高.为进一步提高我国交通运输设备制造业的能源消耗效率,政策的重点应放在提高交通运输设备制造业的间接消耗效率和提高所有产业能源的直接消耗效率.     

Storage yard operations in container terminals: Literature overview,trends, and research directions

Inbound and outbound containers are temporarily stored in the storage yard at container terminals. A combination of container demand increase and storage yard capacity scarcity create complex operational challenges for storage yard managers. This paper presents an in-depth overview of storage yard operations, including the material handling equipment used, and highlights current industry trends and developments. A classification scheme for storage yard operations is proposed and used to classify scientific journal papers published between 2004 and 2012. The paper also discusses and challenges the current operational paradigms on storage yard operations. Lastly, the paper identifies new avenues for academic research based on current trends and developments in the container terminal industry.