Association of solid fuel use with risk of stunting in children living in China

Stunting adversely affects physical and mental outcomes of children. It has not been examined whether household air pollution from solid fuel combustion is a risk factor for stunting in children. In a total of 41,439 children aged 6-17 across China, height was measured using a unified protocol. Multivariable linear regression models and logistic regression models were used to assess the associations of solid fuel use for cooking/heating with stunting in children. Adjusted for covariates, cooking/heating with solid fuel was significantly associated with a lower z-score for height for age and sex (β = −0.21 [−0.32 to −0.09] and −0.17 [−0.31 to −0.03], respectively) and an increased risk of stunting with an estimated ORs of 1.34 [1.07~1.68] and 1.37 [1.02~1.83], respectively. The risk of stunting associated with solid fuel use was statistically significant in high-age children. And the effect was greater on girls than on boys, though the difference was not statistically significant. Our study suggested that Chinese children living in households using solid fuel had a significantly higher risk of stunting than those living in households using cleaner fuel.     

Cu-Mg/Al_2O_3催化乙醇和乙二胺合成N-乙基乙二胺

在固定床反应器内,乙醇和乙二胺经分子间催化胺化反应合成了N-乙基乙二胺(NEED),考察了一系列铜系催化剂的活性,并筛选出催化性能较好的Cu-Mg/A l2O3催化剂;通过X射线衍射和透射扫描电子显微镜方法表征了助剂Mg对Cu/A l2O3催化剂的改性作用;考察了助催化剂Mg含量、反应温度、反应压力、进料量和乙二胺含量等对Cu-Mg/A l2O3催化剂性能的影响。实验结果表明,Cu-Mg/A l2O3催化剂具有很好的活性和选择性;在200℃、3.0MPa、质量分数20%的乙二胺乙醇溶液、进料量1.0mL/m in的条件下,乙二胺的转化率为71.56%,产物NEED的选择性和收率分别为92.62%和69.86%;经过20 d的连续使用表明,Cu-Mg/A l2O3催化剂具有良好的稳定性。     

用JHS-3胶合砂防粉细砂

针对孤东油田大量油井出现粉细砂甚至粘土砂而严重影响生产的问题,研制了用JHS-3胶合砂防粉细砂方法。介绍了胶合砂的基本配方、主要技术指标及防砂机理。适应性分析结果表明,施工井的层数、处理半径和施工压力升幅3个因素直接影响着胶合砂的防砂堵水效果。现场20井次的应用情况可看出,胶合砂能有效地防住粉细砂和粘土砂,明显地改善产液剖面,并有显著的降水增油效果。     

检测骨架图形特征点的新方法

端点、折点、歧点和交点是骨架图形的重要特点是，提出用快速查表法检测侯选特征点，再进行侯选特征点聚集，用局部结构分析，去除假特征点，判别真特征点的类型，并对折点给以大致的定量描述。实验结果表明，该方法能快速有效地找出骨架图形的特征点，在目标识别、字符识别等应用中起着关键作用。     

提高压力过滤器滤套使用寿命的途径

佳木斯造纸厂从芬兰奥斯龙公司引进了一套新型、高效、低碱流失的压力过滤、洗涤苛化系统。本文就如何延长该系统主体元件──滤套的使用寿命这一技术问题，进行系统的阐述。     

变频器的选型及配置要点

本文针对应用广泛的通用变频器，提出了在变频器选型和外围配置中需要注意的一些问题。     

2#板坯连铸机振动台故障分析及改造

论述了银山型钢有限公司炼钢厂2#板坯连铸机自投产以来其振动台存在的问题，根据实际情况分析论证并进行改造实施，实施后效果明显。