新型路基同心筒热冲击机理与热环境影响因子

针对新型同心筒自力发射高速热冲击载荷下热环境评估与影响因子决策问题，结合弹性变形和域动分层结合的动网格技术，求解了二维轴对称Navier-Stokes方程，分析了新型路基同心筒流场机理与热冲击特性，并确定了热环境评价指标；通过建立以优化拉丁超立方试验设计和径向基神经网络为理论基础的近似数学模型，解决了CFD自动建模困难、计算量大的难点；结合径向基神经网络训练方法，对导弹热环境的影响因子进行了智能决策研究。分析表明:倒吸进入新型同心筒内筒的低温气体有力改善了同心筒热环境；建立的近似模型精度较高，满足工程需求；对导弹热环境的影响因子从大到小依次为筒底导流板直径、筒底导流板长度、导流器高度；为导弹热环境多学科优化设计提供参考。     

CMSC型固化剂改良土的新型CBR试验研究

针对苏北某高速公路沿线特殊软土的特点,采用两种方案按全粉料配料的方法配制CMSC型固化剂,并按一定剂量掺入土中。同时,考虑当地的水文气候因素,针对传统钢制击实筒的饱水条件偏保守的特点,研制了新型击实筒,在新型击实筒内制备试件并养护至规定龄期,采用新型浸水装置饱水,进行贯入试验。结果表明,试件的各向饱水条件更接近实际工况,增强了CBR值的可信度。CMSC型固化剂改良土的改良效果优于石灰改良土,且固化剂掺入剂量存在最佳掺量,同时分析了CMSC型固化剂的加固机理,为进一步研究和工程应用提供了参考。     

Breathing air from protein foam

Protein foams can be used to extinguish fires. If foams are to be used to extinguish fires where people are present, such as in high-rise buildings or ships, then a method for allowing people to breathe in a foam-filled environment is needed. It is proposed that the air, used to create the foam be used for breathing. A canister that will break incoming air-filled foam has been designed for attachment to a standard gas mask, in order to provide breathable air to a trapped person. Preliminary results for the modified mask indicate feasibility of breathing air from air-filled protein foam.     

线性流量阀内筒孔形状设计问题研究

对于双筒式线性流量阀,内筒孔形状设计是关系到线性流量阀的过流面积能否"线性变化"的核心问题.从工程实际应用出发,对线性流量阀的内筒孔进行了分段地形状设计.经设计的内筒设计能够使线性流量阀的线性控制区达到90%以上,"过流面积"也完全能够达到"最大范围".设计的内筒孔主体形状为矩形和简单曲线组成,易于加工制造.     

GC-MS/FID测定环境空气中57种臭氧前体物

建立了GC-MS/FID测定环境空气中57种臭氧前体物的分析方法。优化三级冷阱捕集温度、三级冷阱解析温度、初始柱温、毛细管色谱柱等实验条件。优化条件为:采用硅烷化的苏玛罐采集环境空气,目标组分经三级冷阱在-180℃低温浓缩富集,80℃解析,初始柱温为15℃,结合中心切割技术,将乙烷、乙烯、乙炔、丙烷、丙烯切割至TG-Bond-Plot-Q+(30 m×0.32 mm×10μm)色谱柱,经FID检测器分析,外标法定量;其他目标组分切割至TR-V1(60 m×0.25 mm×1.4μm)毛细管色谱柱,进入MS检测器分析,采用全扫描模式(SCAN)和选择离子模式(SIM)同时进行测定,内标法定量。结果表明:当取样量为400 mL时,乙烷、乙烯、乙炔、丙烷、丙烯具有良好的线性关系,且相关系数均大于0.9990,方法检出限为0.05~0.13 nmol·mol^-1;其他目标组分的平均响应因子的相对标准偏差均小于10%,方法检出限为0.05~0.25 nmol·mol^-1,平均回收率均在70.0%~120%之间。本方法解决了湿度和二氧化碳对低碳轻烃组分的干扰,精密度好、准确度高,适用于环境空气中57种臭氧前体物的定性、定量分析。     

罐采样-预浓缩/气相色谱-质谱联用测定污染源废气中118种挥发性有机物

该文采用预浓缩/气相色谱-质谱联用仪(配FID检测器)结合Dean Switch中心切割和冷柱箱技术,建立了一针进样同时测定污染源废气中118种挥发性有机物(VOCs)的分析方法。废气样品采用苏玛罐收集,稀释后进系统分析,其中C2~C3组分在FID上测定,外标法定量;其他目标物在质谱(MS)上测定,内标法定量。结果显示,118种VOCs在0.5~30 nmol/mol浓度范围内线性良好,相关系数(r2)为0.995 3~0.999 9,方法检出限为0.01~0.38 μg·m-3,定量下限为0.03~1.51 μg·m-3;在低、中、高3个加标水平下的回收率为76.4%~110%,相对标准偏差(RSD,n=7)为0.30%~6.0%。将其应用于移动污染源(叉车)及固定污染源(制鞋厂、家具厂、印刷厂、塑料厂、造船厂)废气样品中VOCs的测定,均有不同程度的检出,其中叉车尾气中总VOCs(TVOC)含量为33.50~35.25 mg·m-3,固定污染源废气中TVOC为44.54~211.71 mg·m-3。该方法简便快速、稳定灵敏、准确度高,适用于移动污染源和固定污染源废气中VOCs的定性定量分析。     

Identification and quantitative determination of diphenylarsenic compounds in abandoned toxic smoke canisters

Knowledge of the exact nature of the constituents of abandoned chemical weapons (ACW) is a prerequisite for their orderly destruction. Here we report the development of analytical procedures to identify diphenylchloroarsine (DA/Clark I), diphenylcyanoarsine (DC/Clark II) and related substances employed in one of the munitions known as "Red canister". Both DA and DC are relatively unstable under conventional analytical procedures without thiol derivatization. Unfortunately however, thiol drivatization affords the same volatile organo-arsenic derivative from several different diphenylarsenic compounds, making it impossible to identify and quantify the original compounds. Further, diminishing the analytical interference caused by the celluloid powder used as a stacking material in the weapons, is also essential for accurate analysis. In this study, extraction and instrumental conditions have been evaluated and an optimal protocol was determined. The analysis of Red canister samples following this protocol showed that most of the DA and DC associated with pumice had degraded to bis(diphenylarsine)oxide (BDPAO), while those associated with celluloid were dominantly degraded to diphenylarsinic acid (DPAA).