HMX与低熔点含能材料混合物的热安定性研究

目的 研究环四亚甲基四硝胺(HMX)与2,4,6-三硝基甲苯(TNT)、2,4-二硝基苯甲醚(DNAN)、3,4-二硝基呋咱基氧化呋咱(DNTF)3种低熔点、高挥发性含能材料混合后的热安定性及相关性质.方法 将HMX与3种低熔点含能材料按照质量比1:1进行混合,采用动态测压热分析法(DPTA)、差示扫描量热法(DSC)...     

造船用双角钢式脚手架的危险点电测

对角钢式脚手架进行应力测试和理论计算研究.采用电测法测试了危险截面的应力大小及分布规律.结果表明,2、4测点是危险点;采用斜弯曲理论进行理论计算,所得结论与实验测试是一致的,其中2点受拉应力作用.上述分析为脚手架的设计、制作和安全使用提供了强度分析依据.同时还对脚手架其他安全问题进行了讨论.     

基于ARCGIS的水泥行业碳排放点源分布与变化分析

首先对水泥行业产能与产量数据进行调研,对不同的工艺采用不同的CO2排放因子系统地计算了2000—2009年各点源企业水泥生产的CO2排放量,在点源企业排放量数据的基础上分析计算了各省份及全国总排放量的年度增长趋势。其次利用ARCGIS绘制了全国水泥行业排放点源年度分布图并分析了其空间分布特征,调查分析了我国水泥企业CO2排放源点源分布与变化规律,对水泥工业节能减排、发展低碳经济的工作具有重要的意义。     

干燥条件下高硫煤低温氧化特性研究

为进一步揭示不同环境条件下高硫煤的低温氧化特性,选取含硫量较低、自燃倾向性较高的褐煤,向其添加不同比例的FeS2,配制成含量分别为3%,5%,7%的混合高硫煤样,利用中国矿业大学自行研制的煤氧化模拟试验系统,测试分析干燥混合煤样在低温氧化过程中,交叉温度和指标气体CO产生量体积的变化。试验结果表明,在低温干燥的条件下,随着FeS2含量的增加,煤样的氧化特性受到抑制:交叉点温度升高;指标气体CO产生量在相同温度时体积降低。因此,在高硫煤层自燃火灾防治过程中,应尽量控制煤层周围环境的干燥度。     

基于AHP法的诱发露天矿作业现场碰撞事故危险点重要度排序

露天矿作业现场运行的设备碰撞事故属于安全生产重大事故,尽管发生并不频繁但是同类事故依然在生产中发生。控制诱发该类事故的危险点是现场安全管理的重点,根据现场的事故案例运用AHP法,通过对危险点排序找出其中的重要度,确定碰撞事故中的主要诱发因素,以此在动态生产中识别系统关键节点的危险性,找到预防同类碰撞事故的有效措施。由于诱发危险点在生产中的复杂性,AHP法解决的只是一段时间内的问题,但也为快速掌握安全预控问题提供了一种研究思路。这样在管理资源有限的条件下,为工艺运行的安全预防和控制提供可靠的保障。     

Flash point prediction for the binary mixture of phosphatic solvents and n-dodecane from UNIFAC group contribution model

The flash point temperature of Tri-n-butyl phosphate(TBP) and Tri-iso-amyl phosphate(TiAP) in n-dodecane binary mixture has been measured for the entire concentration range using the continuously closed cup flash point apparatus based on the ASTM D6450 method. The flash point was predicted using the UNIFAC group contribution model. The measured flash point was also compared with the prediction from the NRTL, UNIQUAC and Ideal solution models. The UNIFAC model is able to predict the flash point fairly well for the TBP–dodecane mixture and for TiAP–dodecane mixture no improvements is obtained over the ideal solution assumption. The flash point shows positive deviation from ideal solution behavior for both the binary mixture.     

基于改进TOPSIS的受灾点需求紧迫性分级研究

地震发生初期,各受灾点对物资需求的紧迫性存在差异。在应急资源有限的情况下,为提高救援效率,应急资源需要按照受灾点需求紧迫性优先级进行分配和调度。首先,构建了受灾点需求紧迫性评价指标体系,并采用博弈论方法将熵权法和层次分析法相结合,确定权重组合系数及各评价指标综合权重。其次,利用马氏距离和灰色关联分析改进TOPSIS方法,建立了受灾点应急物资需求紧迫性分级模型。最后,将模型应用于受灾点应急物资需求紧迫性分级研究,并将该评价结果与传统TOPSIS法的评价结果进行比较,结果表明,该评价方法可以科学、客观地确定权重组合系数,消除指标间相关性,使评价结果符合实际情况,表明该评价方法科学、可行、有效,能为应急救援物资配送提供有效支持和决策。     

抚育间伐对栓皮栎种群空间分布格局的影响

抚育间伐是一种重要的改善林木生长条件的经营措施,对林分结构和动态具有重要影响。为研究抚育间伐对林木种群空间结构与格局影响的内在机制,以间伐和未间伐的栓皮栎人工林为研究对象,通过设置2个100 m×100 m样地并进行每木定位和调查,在采用径级结构代替年龄结构方法将栓皮栎种群划分为幼树(2 cm≤DBH<5 cm)、小树(5 cm≤DBH<13 cm)和大树(DBH≥13 cm)3个生长阶段的基础上,分别采用Ripley’s K函数衍生的g(r)函数和双变量g12(r)函数,对栓皮栎种群空间分布点格局及不同生长阶段栓皮栎种群之间的关联性进行了研究。结果表明,间伐和未间伐样地栓皮栎种群空间分布点格局分别在0-16 m和0-33 m距离尺度内呈聚集分布,而分别在大于16 m和33 m距离尺度内呈随机分布;间伐和未间伐样地栓皮栎幼树、小树和大树的株数比分别为8?741?699和261?1134?683,且间伐样地栓皮栎幼树、小树和大树种群分别在0-14、1-16、0-6 m距离尺度内呈现均匀或聚集分布,而在其他距离尺度上表现为随机分布;栓皮栎幼树、小树和大树之间仅在间伐样地0-6 m距离尺度内呈现一定的相关性,而在未间伐样地更大的距离尺度内有显著的关联性,如栓皮栎幼树和大树之间在6-38 m距离尺度上呈显著正相关。因此,抚育间伐一定程度上使得栓皮栎种群在更大距离尺度上呈现出随机分布状态,并弱化了不同生长阶段的林木栓皮栎种群的关联性,这调整了栓皮栎种群空间竞争关系,有利于大径级林木个体的培育。该研究可以为开展抚育间伐对林木种群的影响的研究提供理论依据,也可以为制定科学合理的抚育技术措施提供参考。     

Assessment of groundwater contamination using geographic information systems

In this study two sites were selected in order to investigate groundwater contamination and spatial relationships among groundwater quality, topography, geology, landuse and pollution sources. One site is the Asan area, an agricultural district where pollution sources are scattered and which is mainly underlain by granite of Cretaceous age. The other site is the Gurogu area of Seoul city, an industrial district where an industrial complex and residential areas are located and which is mainly underlain by gneiss of Precambrian age. Groundwater samples collected from these districts were analysed for chemical constituents. An attribute value files of chemical constituents of groundwater and the spatial data layers were constructed and pollution properties were investigated to establish out spatial relationships between the groundwater constituents and pollution sources using geographic information systems (GIS).Relatively high contents of Si and HCO₃ ^– in the groundwater from the Asan area reflect the effect of water–rock interaction whereas high contents of Cl^–, NO₃ ^– and Ca²⁺ in the groundwater from the Gurogu area are due to the pollution of various sources. The significant seasonal variation of SiO₂, HCO₂ ^– and Ca²⁺ contents, and that of Ca²⁺ content were observed in the Asan and the Gurogu areas, respectively. Seasonal variation of pollutants such as Cl^–, NO₃ ^– and SO₄ ^2– was not observed in either area. Pollution over the critical level of the Korean drinking water standard has been investigated from 15 sampling sites out of 40 in the Asan area, and 33 sampling sites out of 51 in the Gurogu area. Pollution by NO₃ ^–, Cl^–, Fe²⁺, Mn²⁺, SO₄ ^2– and Zn²⁺ in the groundwater from the industrial district (Gurogu area) and that of NO₃ , SO₄ ^2– and Zn²⁺ in the groundwater from the agricultural district (Asan area) were observed. The principal pollutant in both areas is NO₃ ^–. Deep groundwater from the Asan area is not yet contaminated with NO₃ ^– except for one site, but most of the shallow groundwater site occurring near the potential point sources is seriously contaminated. From the result of buffering analysis, it seems clear that factories and stock farms are the principal pollution sources in the Asan area. The groundwater from the Gurogu area has already been seriously polluted considering the fact of NO₃ ^– contamination of deep groundwater. Chlorine pollution of shallow groundwater in the Gurogu area was also observed. Spatial relationship between pollution level and its source was clarified in this study by using GIS, which will be applicable to the effective management of groundwater quality.