Thermal hazard analysis of 1-((cyano-1-methylethyl) azo) formamide and effect of incompatible substances on its thermal decomposition

1-((cyano-1-methylethyl) azo) formamide (CABN) is an azo compound that exhibits high thermal sensitivity and self-reactivity. Because of incorrect operation, incompatible substances and other dangerous conditions, thermal explosion accidents may occur during the manufacturing, storage, and transportation of CABN. The pyrolysis characteristics of CABN and its mixture for various heating rates were assessed using differential scanning calorimetry. The results showed that incompatible substances increased the risk of CABN. Moreover, the thermal runaway of CABN under an adiabatic condition was studied using an adiabatic rate calorimeter to obtain the parameters under adiabatic condition. Based on the experimental data, the kinetic parameters of CABN and its mixtures were obtained. In addition, a thermal decomposition kinetic model of CABN was created using Thermal Safety Series. All experiments have shown that the conditions and parameters of CABN must be strictly controlled.     

Mathematical methods for application of experimental adiabatic data – An update and extension

The paper represents some results of comparative analysis of the methods used for processing and interpreting data of adiabatic calorimetry as well as applying it to practical situations. Specifically two approaches are compared – approximate method based on evaluation of simplified kinetics and a more comprehensive, simulation-based method that utilizes the evaluation of more detailed kinetic models.The analysis is focused on two important types of data processing – correction of experimental results on thermal inertia (phi-factor correction) and estimation of adiabatic time to maximum rate (TMR).The most widely cited method for phi-factor correction is considered and its improvement is proposed to enable more precise prediction of the adiabatic time scale. A procedure for phi-factor correction of pressure response is also proposed. The limitations of this enhanced Fisher's method are discussed by comparison with simulation-based method. All the illustrative materials are based on real examples.As an example of application, the simplified method will be used to predict TMR and its limitations will be discussed.     

基于DE-BPNN模型的含腐蚀缺陷管道失效压力预测*

为提升含腐蚀缺陷管道失效压力预测精度,准确把控管道状态,建立基于DE-BPNN的含腐蚀缺陷管道失效压力预测模型,有效避免BPNN模型陷入局部最优问题,提升预测精度。基于61组管道爆破实验数据,分别用DE-BPNN与BPNN模型进行仿真计算。结果表明:DE-BPNN预测结果平均相对误差为3.26%,R²为0.985 85,预测精度较BPNN模型有明显提升。应用DE-BPNN模型预测含腐蚀缺陷的管道失效压力可为长输管道运输调配和检维修提供决策支持。     

起重机主梁变形三维激光扫描检测技术研究

在役起重机主梁变形是导致起重机事故发生的重要因素之一。国内现阶段对于起重机主梁变形检測还停留在传统的检测方法。其检测低效率、实施高风险、结果多误差等因素使传统检测方法暴露出诸多弊端。文章通过对比验证,引入三维激光扫描检测方法,对起重机主梁腹板进行扫描并建模分析得出主梁腹板整体变形的结果,此方法可以提高腹板变形检测数据精度、检测效率与结论的可靠性。扫描数据是整个腹板的点云数据,结果更全面,可以体现腹板整体的变形情况。     

枣庄市大气颗粒物扫描电镜分析和来源识别

应用扫描电镜-X射线能谱对枣庄市大气颗粒物进行定性分析,得出如下结论：（1）枣庄市大气颗粒物中含有燃煤颗粒、土壤颗粒、水泥颗粒、汽车尾气颗粒、石膏颗粒、植物残体颗粒和未知颗粒;（2）依据颗粒粒数百分比统计结果。得出枣庄市大气颗粒物以水泥颗粒、土壤颗粒和燃煤颗粒为主,汽车尾气颗粒和其它颗粒含量很少;（3）对枣庄市大气颗粒物平均粒径进行统计,得出枣庄市大气颗粒物平均粒径集中分布在2．5μm～20岬范围内,其粒数百分比在80％以上。     

底泥性质和分布密度对颤蚓迁移运动的影响

通过实验室模拟颤蚓的迁移,研究了颤蚓分布密度、底泥性质对颤蚓迁移运动的影响.结果表明,分布密度增大引起食物短缺,颤蚓迁移率首先增大,之后由于迁移运动的能量消耗导致迁移率减小,当分布密度大于8×104条.m-2后,颤蚓对食物极度竞争使其开始大规模迁移,最大迁移率为36.75%.底泥有机质在丰富颤蚓食物源,增大其迁移率的同时,也降低了溶解氧浓度,导致迁移率减小,有机质含量由3.93%增加至5.90%时以迁移率增大为主,大于5.90%时则以迁移率减小为主.TN、TP可改变底泥中微生物群落结构,引起颤蚓食物组分变化,从而影响颤蚓迁移,TN和TP含量分别在3.36～5.65mg.g-1和0.95～1.87mg.g-1范围时,TN含量的增加减小了颤蚓迁移率,TP含量的增加则增大颤蚓迁移率;继续增大含量,颤蚓对TN具有一定耐受性,迁移率稳定在20%左右,对TP则表现出排斥性,含量超过1.87mg.g-1后,迁移率从42%降为0.5%.颗粒粒径对颤蚓迁移的影响主要是由颗粒中有机质含量而非粒径本身决定,粒径小于0.15mm和大于0.55mm的颗粒适宜颤蚓生存,前者有机质含量高,后者则颗粒间空隙大,颤蚓可快速通过并获取更多的食物.     

澳门夏季大气颗粒物单颗粒微观形貌分析

应用高分辨率场发射扫描电镜(FESEM)和图像分析技术,研究了澳门地区夏季(2007年7月)大气可吸入颗粒物的形貌特征以及不同种类颗粒物的数量-粒度和等效体积-粒度分布.结果表明,澳门可吸入颗粒物中,烟尘集合体和矿物颗粒普遍存在;矿物颗粒为不规则状,烟尘集合体有链状、蓬松状等形态;烟尘集合体在数量上平均分别约占30%～40%,矿物颗粒在数量上平均分别约占20%,烟尘集合体颗粒较多说明澳门夏季受机动车尾气影响较重.澳门大气PM₁₀的等效粒径主要分布在0.2～0.4　μm范围内,主要为较细粒子.颗粒物种类有明显的地点差异,交通繁忙的高士德马路路口以烟尘集合体居多(平均47%),且其粒径在较宽范围内都有分布（0.1～0.8 μm）;隧道内亦以烟尘集合体的比例较大,可高达59%;货运码头采样点以矿物颗粒较多.     

煤炭企业差序格局下员工安全行为路径研究*

为促进煤炭企业员工安全行为,减少生产安全事故,基于差序格局理论、资源保存理论和自我决定理论,构建差序式领导、组织认同、安全动机和员工安全行为的链式中介模型。通过路径检验和Bootstrap方法,对367名煤炭企业基层员工的有效问卷数据进行统计分析,探讨激发员工安全行为的有效路径。研究结果表明:煤炭企业中的差序式领导可正向影响员工安全遵从行为和安全参与行为,且对安全参与行为的促进作用更强;组织认同和安全动机在差序式领导与员工安全遵从行为、安全参与行为的关系中存在独立中介和链式中介作用,且相较于组织认同,安全动机的独立中介作用更强。研究结果可为建立合理的差序标准、采取适度偏私手段提供参考。     

Seventy‐One Important Questions for the Conservation of Marine Biodiversity

The ocean provides food, economic activity, and cultural value for a large proportion of humanity. Our knowledge of marine ecosystems lags behind that of terrestrial ecosystems, limiting effective protection of marine resources. We describe the outcome of 2 workshops in 2011 and 2012 to establish a list of important questions, which, if answered, would substantially improve our ability to conserve and manage the world's marine resources. Participants included individuals from academia, government, and nongovernment organizations with broad experience across disciplines, marine ecosystems, and countries that vary in levels of development. Contributors from the fields of science, conservation, industry, and government submitted questions to our workshops, which we distilled into a list of priority research questions. Through this process, we identified 71 key questions. We grouped these into 8 subject categories, each pertaining to a broad component of marine conservation: fisheries, climate change, other anthropogenic threats, ecosystems, marine citizenship, policy, societal and cultural considerations, and scientific enterprise. Our questions address many issues that are specific to marine conservation, and will serve as a road map to funders and researchers to develop programs that can greatly benefit marine conservation. Setenta y Un Preguntas Importantes para la Conservación de la Biodiversidad Marina     

铋电极差分脉冲伏安法测定水中痕量2,4-二硝基苯肼

以自制铋电极作为工作电极，建立了铋电极差分脉冲伏安法测定2，4-二硝基苯肼的分析方法。实验结果表明：以0.1 mol/L NaOH+0.1 mol/L KCl混合溶液（pH=13.0）配制测定底液，在扫描速率为100 mV/s的条件下，2，4-二硝基苯肼于-0.53 V处产生灵敏的氧化峰;在2，4-二硝基苯肼浓度为3.0×10-8~1.0×10-5 mol/L范围内，空白和试样的氧化峰电流强度差值与对应2，4-二硝基苯肼浓度的对数呈良好的线性关系，检出限达8.37×10-9 mol/L;将该方法应用于工业废水中痕量2，4-二硝基苯肼的检测，回收率为95.6%~103.1%，相对标准偏差小于3%。