三维荧光二阶校正法快速测定环境水体和淤泥样中麦穗宁残留量

将激发发射荧光光谱与化学计量学基于交替三线性分解（ATLD）算法的二阶校正方法相结合,实现了自来水、湘江水、池塘水、雨水和淤泥5种实际复杂体系中麦穗宁含量的直接快速定量测定.当选取组分数为2时,用ATLD算法分辨获得的平均回收率分别为（100.5±1.3）%、（93.8±1.1）%、（95.0±2.1）%、（98.2±...     

烟根腐解物对烟草生长的影响

烟草生产过程中会产生大量烟草残体,为了研究烟草残体对烟草生长的影响,将烟根、水稻土和无菌水按一定比例混合后,在适当条件下培养得到烟根腐解物.将烟根腐解物按不同的施用量设置6个处理组,并以未施用烟根腐解物组作为对照,分别在烟草生长的团棵期、旺长期和成熟期测定烟草的农艺性状、根系活力、硝酸还原酶(nitrate reduc...     

过氧化氢异丙苯热稳定性与热安全性研究

为研究过氧化氢异丙苯(CHP)的热稳定性和热安全性,利用C80微量量热仪对CHP在空气中的热分解进行试验研究。利用热分析技术研究CHP的热分解,得到了升温速率对CHP热分解的影响,CHP热分解的活化能,绝热条件下最大反应速率到达时间Tmrad和不同包装下的自加速分解温度。结果表明:随着升温速率的增加,CHP的起始放热温度和最大放热温度随之升高;CHP热分解的活化能范围为52～91 kJ/mol;Tmrad为1,8,24,50和100 h时对应的起始温度分别为118.08,75.41,55.83,44.83和34.52℃;CHP的储罐内径越大,其对应的自加速分解温度越低。     

基于现代数学思想对安全生产控制指标分解方法的研究

随着我国安全生产状况逐年稳定好转,传统的安全生产控制指标层层分解的方法正面临着分解空间日益狭小、指标难于分解的挑战。为增强指标分解方法的理论性和科学性,力求真正意义上反映地方政府在安全生产工作中的实际成效,本文作者以创新方法为突破口,结合现代数学理论中＂加权平均预测法＂、＂弹性系数预测法＂等数学思想,对我国安全控制指标分解方法进行了延伸性的创新研究,提出了＂五年平均降幅定权重法＂和＂相对指标反推绝对指标法＂两种控制指标分解方案,为安控指标的分解方法提供了新的思路。     

居民食物消费变化引致的环境足迹测算

首先对比分析了2014～2020年城乡居民食物消费结构的变化特征,其次测算了人口规模、城镇化率、人均食物消费量和食物消费结构变化对土地-水-碳足迹变化的影响程度,最后设计了食物现状消费结构S0、发展消费结构S1和更趋近膳食指南的最优消费结构S2三种情景,测算了2025年和2030年3种情景下居民食物消费引致的环境足迹.结果表明:人均食物消费量和消费结构逐渐成为影响环境足迹的主要因素,2018～2020年城镇(农村)居民人均食物消费量和消费结构对环境足迹的平均贡献率分别为51.1%(51.6%)和-17.4%(-13.1%); S1和S2下居民食物消费引致的环境足迹均小于在S0下的值.在S2下环境足迹的减少更明显.在2025年城镇(农村)居民在S2下食物消费引致的土地、水、碳足迹比在S0下减少10.5%(11.5%)、19.6%(17.2%)、12.6%(13.7%);在2030年将减少11.6%(11.9%)、21.0%(16.8%)、13.6%(14.7%).基于分析结果,提出了如何减少食物消费引致的环境足迹的建议.     

Effects of metal ions on thermal hazard of tert-butyl peroxy-3,5,5-trimethylhexanoate

As a commonly used initiator for polyethylene, tert-butyl peroxide 3,5,5-trimethylhexanoate (TBPTMH), with the molecular formula of C₁₃H₂₆O₃, is more likely to decompose and cause fires and explosions. Understanding the thermal risks of TBPTMH mixed with common metal ions, potentially in containers and pipes, is important. In this work, by using differential scanning calorimetry (DSC) and Phi-Tec adiabatic calorimetry, the effects of CuCl₂, FeCl₃, CuBr_2, and FeBr₃ on the thermal decomposition of TBPTMH were investigated. Adiabatic kinetic analysis was performed and the apparent activation energy (E_a) was calculated by thermodynamic analysis. Time to maximum rise under adiabatic conditions (TMR_ad) and the self-accelerating decomposition temperature (SADT) under different packing qualities were reckoned. It was found that the thermal risk of TBPTMH was increased while mixing these metal ions, especially CuBr₂. To ensure the safety of the substance in process industry, the temperature of TBPTMH in the presence of metal should be governed below 39.48 °C. This work was expected to provide some guidance for improving the process safety of TBPTMH.     

A novel approach combining bootstrapped non-intrusive reduced order models and unscented transform for the robust and efficient CFD analysis of accidental gas releases in congested plants

The risk assessment for safety-critical, complex systems is a very challenging computational problem when it is performed with high-fidelity models, e.g. CFD, like in the case of accidental gas releases in congested systems. Within this framework, a novel CFD approach, named Source Box Accident Model, has been recently proposed to efficiently model such phenomena by splitting the simulation of the gas release and its subsequent dispersion in the system in two steps. In this view, the present paper proposes a non-intrusive, Proper Orthogonal Decomposition-Radial Basis Functions reduced order model that exploits the two-step nature of the SBAM approach, to mimic the behaviour of the original, long-running CFD model code at a significantly lower computational cost. Moreover, the paper presents a methodology combining the bootstrap and unscented transform approaches to efficiently assess the ROM uncertainty in the safety-critical simulation output quantities of interest, e.g. the flammable volume. The results obtained in a test case involving a high pressure, accidental gas release in an off-shore Oil & Gas plant are in very satisfactory agreement with those produced by CFD, with a relative error smaller than 10% and a reduction in the computational time of about three orders of magnitude.     

活性炭分解臭氧机制研究

通过臭氧降解处理器尾气含量测定、温度测定和热量分析等研究了活性炭催化降解O3的效果和作用机制.结果表明,当O3的流量为12.89 mg.min-1,以充填2.0～2.5 mm煤质颗粒活性炭、直径18 mm玻璃柱为降解处理器,O3可以得到充分降解(分解效率始终维持100%),且效果可维持5 h以上.研究中发现活性炭催化降解处理器有升温现象,温度上升至65～69℃左右后,趋于平缓,期间CO2等氧化气体的释放量随温度稳定而减小.降解机制分为3部分:其一为活性炭发挥催化作用,活性炭的强烈吸附能力导致局部位置臭氧的富集和自身降解为氧气;其二为活性炭参与反应,臭氧破坏活性炭表面结构和基团,生成CO2和NOx等产物随尾气释放;其三为臭氧以上述2种机制降解形成氧气和各种氧化物时产热导致降解区域温度升高,进一步促进臭氧热降解.同时,还探讨了根据上述温度变化规律设计降解处理器的可能性.     

防火树种阻火特性的实验研究

以木荷作为防火树种 ,首先利用热重装置分别研究了其树干和枝叶的热解失重过程 ,从得到的热重曲线TG、DTG中发现 ,伴随着温度的升高 ,试样发生了三次失重高峰 ,并且 5 0 0℃时的残留物不及其初始重量的 10 %。然后在燃料床上以松针为燃料 ,分别模拟了 2 0°和 30°等小坡度情况下地表火的蔓延过程 ,通过分析热电偶记录下来的温度场分布 ,研究了火蔓延过程中防火树种在火焰和坡度作用下的阻火特性和阻火机理 ,结合其热解特性的研究 ,论证了水分析出是防火树种发挥阻火性能的关键因素 ,得到一些对生物防火技术研究有用的结论 ,为更好的利用和发展生物防火技术来预防和控制大规模森林火灾提供了理论基础。     

Investigation of heat transfer and heterogeneous reactions during the slow cook off of a composite propellant

In this work, a new modelling of interactions between components of aluminium/ammonium perchlorate/HTPB propellant during slow heating is presented. The phenomenon was previously described by experimental approaches performed in the laboratory. Heat and mass balance will be considered both in the solid and gas phases. The interaction of the decomposition products of both ammonium perchlorate and HTPB binder is shown thanks to previous experiments and a specific numerical model allows us to reproduce this trend. Mass and heat transfers are taken into account in each particle of ammonium perchlorate and inside the matrix of the HTPB binder. The chemical reaction in the gas phase is in interaction with the adsorption desorption of several species with regard to the surface grains. The whole set of equations is solved thanks to Comsol multiphysic solver and the numerical results are compared with mass loss measurements by means of a thermogravimetric device.