Molecular composition of recycled organic wastes,as determined by solid-state 13C NMR and elemental analyses

Using solid state ¹³C NMR data and elemental composition in a molecular mixing model, we estimated the molecular components of the organic matter in 16 recycled organic (RO) wastes representative of the major materials generated in the Sydney basin area. Close correspondence was found between the measured NMR signal intensities and those predicted by the model for all RO wastes except for poultry manure char. Molecular nature of the organic matter differed widely between the RO wastes. As a proportion of organic C, carbohydrate C ranged from 0.07 to 0.63, protein C from <0.01 to 0.66, lignin C from <0.01 to 0.31, aliphatic C from 0.09 to 0.73, carbonyl C from 0.02 to 0.23, and char C from 0 to 0.45. This method is considered preferable to techniques involving imprecise extraction methods for RO wastes. Molecular composition data has great potential as a predictor of RO waste soil carbon and nutrient outcomes.     

化学纤维栅湿式过滤除尘的实验研究

化学纤维栅湿式除尘是一种复合机理的新型湿式过滤除尘技术,其过滤风速为2～10m/s,阻力仅为200～500Pa,除尘效率达到99.62％,能很好解决矿山溜井卸矿产生的粉尘,使溜井含尘气流经净化后达到新鲜风流卫生标准。     

腈纶粉尘对作业工人健康影响的调查

为探讨腈纶粉尘对作业工人健康的影响,对某腈纶厂毛条车间进行了劳动卫生学调查.该车间粉尘浓度为4.2(0.1～24)mg/m3,主要对接触人员上呼吸道和皮肤有刺激作用,同时导致肺通气功能受到明显损伤,部分工人胸部X线表现异常.提示车间环境中时间加权平均容许浓度超过2mg/m3、短时间接触容许浓度超过4mg/m3尘的卫生标准不能充分保护工人健康.     

黏胶纤维厂特征污染因子的筛选及其对河流水质的影响

以丹东化学纤维公司为例,对黏胶纤维厂生产工艺进行了分析,并对其污染源进行了调查、监测,物料衡算及污染因子的评价,筛选出了主要污染物、特征污染物与评价因子,并运用水质预测模型对其纳污河流的水质影响进行了研究。     

SO2采样方式改变后的质量分析

环境空气SO2采样由每天采样3次,每次采样30分钟的瞬时采样变成24小时的连续采样,其测定浓度都降低了。其原因主要有,监测点位重新布设后,有些采样点位向郊区转移、进气管接胶管采样、进气管有水、采样流量变小及延迟化验分析等,都影响采样结果。     

多种损伤影响下正交层合板刚度退化研究

通过对纤维增强树脂基复合材料层合板的细观力学分析,建立了基体裂纹和纤维断裂2种损伤共存时正交层合板刚度退化模型.给出了纤维断裂损伤的计算方法,对正交层合板刚度退化过程进行了量化计算.结果表明,所建立的模型采用较少的几个参数即可描述层合板刚度退化过程,并与试验结果吻合较好.     

电磁屏蔽织物孔洞区域金属纤维排列特征分析

本文介绍了电磁屏蔽织物孔洞区域金属纤维排列对屏蔽效能的影响,通过提取孔洞区域金属纤维,并与正常织物中金属纤维的排列进行对比,给出了定量表述金属纤维特征的参数,如密度、取向度和整齐度等,描述了孔洞区域金属纤维的排列特征。根据定量表述参数,结合织物样品屏蔽效能测试结果,对比金属纤维参数不同的织物样品屏蔽效能测试结果,得出孔洞区域金属纤维的密度、取向度和整齐度不同,有孔洞织物屏蔽效能也不同的结论。     

西南地区秋绵雨变化趋势与周期性特征的区域差异

利用西南地区338 个气象站点1961-2009 年9-11 月的逐日降水资料,采用REOF对秋绵雨进行气候分区,运用线性趋势、滑动t 检验、Yamamoto 检验、Mann-Kendall 检验、复Morlet 小波等数学方法,分析各分区秋绵雨日数的变化趋势、突变特征、周期性特点,结果发现：西南地区秋绵雨东多西少,四川东南部、重庆西南部和贵州北部秋绵雨最多,年发生率在80%以上,年均日数在10 d 以上;西南地区秋绵雨可分为4 个气候区,即四川盆地东部区、黔南区、四川盆地西部区和滇东北区;其中四川盆地东部区、黔南区、四川盆地西部区秋绵雨日数有减少趋势,滇东北区有增加趋势,但均不显著;黔南区秋绵雨日数在1988 年发生了由多到少的突变,滇东北区秋绵雨日数则在1985 年和1995 年发生了两次相反的突变;各分区秋绵雨日数的年代际振荡周期差异较大,从10 a 到27 a 不等,年际振荡周期四川盆地东部区和黔南区为2～5 a尺度,四川盆地西部区和滇东北区为2～3 a尺度。     

Simulation studies of ammonia removal from water in a membrane contactor under liquid–liquid extraction mode

Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH₃ in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors.     

水质监测中的快速传感技术

传感器的发展是水质监测中的关键技术之一。以水质调查对监测技术的需求和相应传感器的发展趋势的分析为出发点,重点介绍了光纤传感器和生物传感器的原理和在水质监测中的应用,指出了快速传感技术应用的重要意义和发展前景。