某型液体火箭动力系统低温环境适应性要求验证试验与结果分析

目的验证动力系统低温环境适应性要求。方法开展低温试验,模拟火箭运载平台在某使用条件下的环境状态,测量火箭运载平台在各典型测点表面温度数据,将实际温度数据及温度变化情况与关键部组件的使用要求进行对比,分析局部实际温度条件是否满足内部关键部组件的使用要求。结果获得低温条件下关注部位温度数据及温度变化情况。结论通过进行低温条件下的试验,验证了此型火箭在一定低温条件下,重点关注部位的温度能够满足产品设计使用技术要求。此结果为此型火箭动力系统低温环境条件下的使用提供了依据。     

不同功能区表层土中全氟化合物污染指纹及其来源解析

为探究区域功能对其表层土中全氟化合物(perfluorinated compounds,PFCs)污染指纹与含量水平的影响,采用固相萃取分离富集、高效液相色谱-质谱联用与源解析相结合的方法,分析了深圳市公园、居民小区、十字路口、工厂周边4个功能区和城市背景共76份表层土中14种PFCs的含量.结果表明,深圳市表层土总PFCs(ΣPFCs)含量受区域功能影响显著,呈工厂周边(P<0.001)>>十字路口(P<0.01)>>居民小区(P<0.05)>>公园>城市背景的分布.其中工厂周边、居民小区、公园表层土中PFCs呈中链(P<0.05)>>长链>短链的分布,而十字路口则呈中链≈短链(P<0.05)>>长链的分布.同时,以全氟辛烷磺酸、全氟辛酸、全氟十三酸为主要标志物的3个主成分可以解释深圳表层土超过81%的ΣPFCs,十字路口以及电镀、油漆厂周边表层土呈现出较清晰的PFCs污染指纹.     

气相色谱法和高效液相色谱法测定废水中N，N-二甲基甲酰胺的比较

为比较气相色谱法和高效液相色谱法测定废水中N,N-二甲基甲酰胺是否存在显著性差异,分别使用这两种方法测定N,N-二甲基甲酰胺含量。结果显示,两种方法的精密度、准确度和测定结果无显著性差异,均可作为测定废水中N,N-二甲基甲酰胺的方法。     

液氨泄漏事故的大气环境危害性模拟预测研究

以液氨储罐泄漏事故对大气环境的影响为研究对象,分析了典型化学品泄漏的大气扩散特征,简要介绍了高斯烟团模型,并使用基于该模型的RiskSystem1.2软件对某假定一次液氨储罐发生灾害性事故状态下的泄漏进行模拟。预测出在一定稳定度、不同风速不同时刻下液氨的半致死浓度、重度及轻度伤害范围等的下风向距离和不同风速条件下液氨的最大落地浓度,以期为使用RiskSystem1.2进行大气环境风险评价提供一定帮助,并在此基础上提出具体的防范措施及应急预案,为该类事故的应急救援工作提供一定参考。     

高效液相色谱三重四级杆串联质谱联用直接进样法测定饮用水水源中的阿特拉津研究

采用高效液相色谱三重质谱联用直接进样法测定地表水中的阿特拉津,样品经0.2μm滤膜过滤后直接上机测定,前处理无需消耗有机溶剂。选用SunFire C18(5μm*4.6 mm*150 mm)色谱柱,流动相为0.1%甲酸乙腈∶0.1%甲酸水=7∶3,流速为0.5 ml/min;质谱条件为电喷雾离子源(ESI+)电离,采用串联质谱多反应监测方式(MRM)检测。该法测定饮用水水源中阿特拉津的最低检出限为0.018μg/L,精密度为0.4%~1.0%,准确度为-0.2%~-6.6%,线性范围为0.5μg/L~100.0μg/L,相关系数为0.999 8,线性良好,能满足环境监测工作的实际应用。     

高温液相色谱法在中药成分检测中的应用

采用高温操作,对六味地黄丸的有效成分进行了分析。当柱温提高到60℃时,采用黏度大而洗脱能力强的异丙醇混合物为流动相,分离时间比升温前缩短30 min;总峰数目为83,其中紫外检测器可识别峰个数为65,蒸发光散射检测器可识别峰个数为59。     

型煤自适应脱硫脱硝特性的实验研究

为了减少民用炉灶和小型工业锅炉燃烧污染,开发了一种自适应脱硫脱硝的型煤,主要由煤、造纸黑液和脱硫脱硝剂混合压制而成,研究该型煤的燃烧过程自适应脱硫脱硝作用。结果表明,造纸黑液可提高型煤的燃烧性能,添加质量分数为20%的造纸黑液,型煤燃尽时间可以缩短25%。同时,造纸黑液还可以脱硫脱硝。当造纸黑液质量分数为10%时,其脱硝效率达到40%,脱硫效率为24%。     

Distributed generation by energy from waste technology: A life cycle perspective

Municipal Solid Waste in general and its organic fraction in particular is a potential renewable and non-seasonal resource. In this work, a life cycle assessment has been performed to evaluate the environmental impacts of two future scenarios using biogas produced from the organic fraction of municipal solid waste (OFMSW) to supply energy to a group of dwellings, respectively comprising distributed generation using solid oxide fuel cell (SOFC) micro-CHP systems and condensing boilers. The London Borough of Greenwich is taken as the reference case study. The system is designed to assess how much energy demand can be met and what is the best way to use the digestible waste for distributed energy purposes.The system is compared with two alternative scenarios fuelled by natural gas: a reference scenario, where the electricity is supplied by the grid and the heat is supplied from condensing boilers, and a fuel cell micro-CHP system. The results show that, although OFMSW alone can only supply between 1% and 4% of the total energy demand of the Borough, a saving of ∼130 tonnes of CO₂ eq per year per dwelling equipped with micro-CHP is still achievable compared with the reference scenario. This is primarily due to the surplus electricity produced by the fuel cell when the micro-CHP unit is operated to meet the heat demand. Use of biogas to produce heat only is therefore a less desirable option compared with combined heat and power production. Further investigation is required to identify locally available feedstock other than OFMSW in order to increase the proportion of energy demand that can be met in this way.     

Numerical investigation into dynamic responses of RC columns subjected for fire and blast

Structures may be exposed to fire and blast due to accidents (i.e. explosion of flammable gas in industrial structures) or terrorist attacks during the service life. Performances of RC structures subjected to extreme conditions of fire and blast, thus, have drawn much attention from academia. In this paper, the coupling effect of high temperature and high strain rate in concrete was firstly studied based on the experimental data to improve the damage plasticity concrete model in ABAQUS. Secondly, the transient heat transfer effects in different fire scenarios and following fire resistances of RC columns with constant axial forces were numerically investigated on the basis of the improved concrete model, which are validated by the corresponding test data, and the residual axial loading capacity of RC columns was quantitatively calculated. By incorporating the different merits of implicit algorithm applied to heat transfer analyses and explicit algorithm usually used in blast analyses, a numerical approach to analyze the responses of RC columns subjected to the coupling loadings of fire and blast was finally developed. Mid-span displacements and damage of the RC columns subjected to fire and explosions were quantitatively calculated and discussed. The proposed approach was demonstrated to be effective in predicting the responses of RC structures subjected to coupling loadings of fire and blast.     

核电站低放射性废水在封闭水体中的输移规律研究

采用EFDC水动力-水质模型对咸宁核电站低放射性废水在封闭型水体富水水库中的输移过程进行了数值模拟,重点分析了富水水库在不利来水条件下(97%保证率),4台机组同时运行时,低放射性废水中6种不同半衰期核素在水库中的浓度分布情况.结果表明,低放射性废水浓度的分布主要受水库流场分布的影响,浓度变化主要受核素半衰期及来水量多寡的影响;同时,随着核素半衰期的延长,低放射性废水在水库中的影响范围逐渐增大,当半衰期延长到5 a以上时,影响范围趋于稳定;此外,由于水库流场流向下游的大坝处,排水口的水流很难回流到上游的取水口处,因此取水口处的水质不受下排水口低放射性物质回流的影响.