基于递阶控制机制的公交网络仿真规划研究

针对城市公交网络的复杂性和现有规划方法的局限性，提出了一种公交网络规划设计的新方法——基于递阶控制的公交网络仿真规划系统，并从问题描述、系统总体设计、分系统设计及实践应用的角度对其进行了详细阐述。     

高温下带金属壳PBX炸药低速撞击敏感性数值模拟

炸药撞击感度和热安全性是评价炸药安全性能的重要指标。为了对高温下炸药撞击敏感性变化规律进行可靠预测,本文中通过数值模拟,研究不同预加热温度下带壳PBX炸药装药在小弹丸低速撞击下的热力学响应,得到炸药点火前至点火阶段局部高温区的位置、形态、温度和应变随时间在炸药中分布的变化。结果显示,炸药发生点火的撞击阈值速度与烤燃温度的关系并非单一随温度升高而降低,而是在加热至348.15 K时达到最高;根据温度和应力应变云图分析可得,随着烤燃温度的提高,炸药强度下降,PBX炸药装药局部高温区快速升温的主导因素由局部剪切变为压缩。热软化对炸药的撞击敏感性起重要作用。     

HMX基多组分PBX结构和性能的模拟研究

用分子动力学(MD)方法，对HMX基含少量TATB、F2311(粘结剂)和石蜡(钝感剂)的4组分PBX的结构和性能进行模拟研究。为细致考察各组分对主体炸药的作用，对2组分体系(HMX/TATB, HMX/F2311和HMX/石蜡)也进行类似的MD模拟。为深入揭示钝感机理和钝感剂的作用，还对HMX和石蜡超分子体系的相互作用进行量子化学第一性原理DFT计算。此外，对纯HMX及以它为基的多组分PBX的爆热和爆速进行了理论估算。结果表明，各PBX的弹性较纯HMX的有所改善，以粘结剂组分对主体炸药的力学性能影响最大。各组分的加入均或多或少地降低主体炸药的爆热和爆速。钝感剂与HMX的相互作用很弱，PBX的钝感性不是由电子结构因素所造成。多组分PBX的理论配方设计需综合考虑各种复杂因素。     

顶空/气相色谱-质谱联用法测定食品接触材料中5-亚乙基-2-降冰片烯的迁移量

建立了顶空/气相色谱-质谱联用(HS/GC-MS)测定食品接触材料中5-亚乙基-2-降冰片烯(ENB)迁移量的方法,对前处理方法(溶剂提取-直接进样和气液平衡-顶空进样)、顶空平衡温度、顶空平衡时间进行了优化。以水、4%(体积分数)乙酸、50%(体积分数)乙醇和橄榄油作为食品模拟物,样品经食品模拟物浸泡,于顶空气液平衡后进样,经DB-5 MS色谱柱(30 m×0. 25 mm×0. 25μm)分离后,采用选择离子模式进行检测,外标法定量。在优化实验条件下,ENB在0. 1～10 mg/L范围内呈良好的线性关系,相关系数(r)大于0. 999,在0. 1、1. 0、10 mg/L 3个加标水平下,方法的回收率为92. 0%～108%,相对标准偏差(RSD,n=5)为0. 9%～4. 0%,检出限(LOD)为0. 01 mg/kg,定量下限(LOQ)为0. 03 mg/kg。该方法准确、可靠、灵敏度高,适用于食品接触材料中ENB迁移量的测定。     

运动损伤可动性模型的构建与应用

从运动损伤学习研究的实践问题出发，提出并初步探讨了运动损伤可动性模型的构建与应用。采用教学实验、问卷调查、数理统计等方法，从主、客观两方面进行了实验研究。结果显示，运动损伤可动性模型的构建与应用是成功的，有利于提高学生对运动损伤的认识、处理和预防，易于推广。     

PBX代用材料动态力学行为和微观结构的实验研究

 研究了固体炸药PBX代用材料D-90031的微观结构、压制过程中产生的原生缺陷形态，以及动态力学行为和破坏特征。采用数字图像分析技术、纳米力学测试系统，以及分离式霍普金森压杆（SHPB）实验和落锤冲击技术，获得了微观结构特点、各组分的硬度和弹性模量、动态性能，以及碎片的尺寸分布规律和材料的破坏形式。研究发现，晶粒的形态随外载的作用而改变，晶粒沿垂直加载方向伸长，材料的碎块尺寸满足一定的规律。研究结果对于深入认识固体炸药的性能与微观结构的关系具有一定的指导意义。     

Mercury transformations in chemical agent simulant as characterized by X-ray absorption fine spectroscopy

Chemical analyses of U.S. stockpiled mustard chemical warfare agent show some agent destined for destruction contains mercury [L. Ember, Chem. Eng. News 82 (2004) 8]. Because of its toxicity, mercury must be removed from agent prior to incineration or be scrubbed from incineration exhaust to prevent release into the atmosphere. Understanding mercury/agent interactions is critical if either atmospheric or aqueous treatment processes are used. We investigate and compare the state of mercury in water to that in thiodiglycol, a mustard simulant, as co-contaminants are introduced. The effects of sodium hypochlorite and sodium hydroxide, common neutralization chemicals, on mercury in water and simulant with and without co-contaminants present are examined using X-ray absorption fine spectroscopy (XAFS).     

Superconducting-state energy gap parameters from specific heat measurements

Summary Thermal analysis of pure RDX and its plastic bonded explosive (PBX) with hydroxyl terminated polybutadiene (HTPB) has been undertaken using TG-DTG and DTA techniques. Isothermal TG has been done and the data therefrom has been used to evaluate kinetic parameters using model fitting method and a model-free isoconversional method. Results of the work done are discussed briefly on a comparative basis by analysing the departure of the thermal behaviour of the PBX from that of RDX.     

细观尺度下塑料粘结炸药热点生成的初步模拟

采用有限元与离散元相结合的方法模拟了塑料粘结炸药在冲击载荷下热点生成的细观过程,计算中炸药晶体采用有限元法,粘结剂采用离散元法。结果表明热点多集中在晶体间变形较大的粘结剂部分,粘结剂与晶体间冲击波的相互作用是热点生成的重要原因;HMX晶体温度明显低于粘结剂,且晶体边界温度高于内部温度。     

Experimental and DEM analyses on wheel-soil interaction

In this paper, the wheel-soil interaction for a future lunar exploration mission is investigated by physical model tests and numerical simulations. Firstly, a series of physical model tests was conducted using the TJ-1 lunar soil simulant with various driving conditions, wheel configurations and ground void ratios. Then the corresponding numerical simulations were performed in a terrestrial environment using the Distinct Element Method (DEM) with a new contact model for lunar soil, where the rolling resistance and van der Waals force were implemented. In addition, DEM simulations in an extraterrestrial (lunar) environment were performed. The results indicate that tractive efficiency does not depend on wheel rotational velocity, but decreases with increasing extra vertical load on the wheel and ground void ratio. Rover performance improves when wheels are equipped with lugs. The DEM simulations in terrestrial environment can qualitatively reproduce the soil deformation pattern as observed in the physical model tests. The variations of traction efficiency against the driving condition, wheel configuration and ground void ratio attained in the DEM simulations match the experimental observations qualitatively. Moreover, the wheel track is found to be less evident and the tractive efficiency is higher in the extraterrestrial environment compared to the performance on Earth.