防止背痛每日诀窍

不管你是在写字、做家务,还是驾车,背痛都会在你毫无察觉的情况下突然袭击。所以你必须防患于未然,及早预防。     

水中油的测定方法探讨

探讨了重量法，紫外光度法测定水中石油类的合适条件和动物油，植物油的干扰。按选定的操作方法测定，取得了满意结果。提供了一个处理石油醚的简单方法。     

Fouling of nanofiltration membrane by effluent organic matter： Characterization using different organic fractions in wastewater

The UF membrane with molecular weight cutoff (MWCO) ranging from 2 kDa to 100 kDa and XAD-8 resin were employed to identify the characteristic of molecular weight (MW) distribution of wastewater effluent organic matter (EfOM) in terms of TOC and UV254, as well as the amounts of the hydrophilic/hydrophobic organic fractions in different MW ranges. Then, the nanofiltration (NF) membrane fouling experiments were carried out using the above fractionated water to investigate the effect of MW distribution and hydrophilic/hydrophobic characteristics of EfOM on the membrane flux decline using the fractionated water samples above. The experimental results have shown that 45.61% of the total organics belongs to the low MW one, among which the percentage of the hydrophilic organics with low MW (less than 2 kDa) was up to 28.07%, while that of the hydrophobic organics was 17.54%. In particular, the hydrophilic fraction was found to be the most abundant fraction in the effluents. MW distribution has a significant effect on the membrane fouling. When the MW was less than 30 kDa, the lower the MW, the larger was the specific flux decline, while in the case of MW higher than 30 kDa, the higher the MW, the larger was the specific flux decline, and the decline degree of low MW organics was larger than the high MW one. With the same MW distribution range, specific flux decline of the hydrophilic organic was considerably slower than that of the hydrophobic organic, which indicated that the hydrophobic organic fractions dominantly contribute to the flux decline.     

红外光度法测油的有关问题的研究

为了研究红外光度法在测油过程中应用的局限性．用重量法和红外法对成品油及污水进行了大量的实验。实验结果表明红外光度法适用高浓度水样中石油较轻组分的测定．对于重组分低浓度的样品．回收率则很低。     

重量法测定粉尘中游离SiO 2 探讨

讨论了重量法测定粉尘中游离SiO2含量分析过程中易出错的焦磷酸制备、残渣转移等试验步骤,提出准确测定的关键是控制温度,并根据对比试验和工作经验改进了分析过程中样品转移的方法。     

降尘测定方法探讨

对三明市降尘分为水溶性降尘和非水溶性降尘进行定，用直接电导法和重则定水溶 了和尘，结果具有良好的准确和精密度，能满足降尘的测定，而且快速易，降低劳动强度，提高工效。     

水中油类重量测定法的改进

"重量法"是现行"环境监测分析方法"中规定的水中含油量分析方法。本文介绍了通过一定的条件试验和数理统计分析,对现行分析方法做了较大的改进,使本方法更为实用。     

地铁爆破施工对建筑物振动影响预测

结合某地铁工程环境影响评价，采用理论分析、公式计算、类比验证等方法，重点研究城市地铁爆破施工作业时，对不同距离处建筑物振动的影响程度。预测结果表明，当药包重量为20Kg时，距爆破点40m外的建筑物将不会受到爆破振动影响。如果距爆破点40m范围内有建筑物存在，则应减小药包重量，以保证建筑物的安全。     

重量法测定水中矿物油的分析方法讨论

就重量法《水和废水监测分析方法》分析水中矿物油的石油醚纯度，烧怀恒重关的烘干温试行最终称量温度不同；萃取时乳化现旬对分析结果的影响，通过实验进行了讨论和分析。     

关于滤纸可溶物对测定悬浮物影响的探讨

针对滤纸可溶物对测定悬浮物结果的影响作了定量和研究。