4种红木尺寸稳定性的研究

采用以DPG为主要成分的药液对印度紫檀 （Pterocarpus indicus）、红酸枝木 （Dalbergia oliveri）、鸡翅木（Cassia siamea）和花梨木（Pterocarpus macarocarpus）4种 红木进行了处理,分析 了不同浓度的药液对处理材ASE和MEE的影响。结果表明, 经过药液处理后试件的ASE和 MEE随 DPG比例的增加而增大,木材尺寸稳定性明显改善,药液中DPG所占比例一般控制在 20%～50%之间,综合效果较好。     

Influence of treatment temperature and duration on selected biological,mechanical, physical and optical properties of thermally modified timber

Abstract

The impact of heat-treatment temperature (180, 200, 210, 220 and 240°C) and various heat-treatment durations on selected biological, mechanical, optical and physical properties of thermally modified timber (TMT) was determined. The suitability of different measures for prediction of the treatment intensity was also investigated. Resistance to impact milling (RIM), lightness L*, equilibrium moisture content (EMC), and antiswelling efficiency (ASE) were correlated with corresponding fungal resistance achieved by heat treatments. The results show that the decrease in mass by heat treatments is a suitable measurand to describe the treatment intensity, which is a product of treatment temperature and duration, where the impact of temperature is dominant over the impact of time. The properties examined showed a strong reciprocally proportional relationship with the decrease in mass. Different correlations were found for the various treatment temperatures: the higher the temperature applied, the lower the decrease in mass required for an equivalent improvement in certain wood properties, e.g. biological durability, EMC and dimensional stability. However, mass loss by Poria placenta correlated well with RIM, lightness L*, EMC and ASE of the different heat-treated specimens, depending on the heat-treatment temperature. Consequently, a reliable estimation of improved fungal resistance of TMT, as well as quality control of TMT in general, requires certain process information.     

杉木浸渍改性材的尺寸稳定性研究

利用聚乙烯醇缩甲醛改性剂对杉木木材进行浸溃改性，对其改性材的尺寸稳定性进行研究。结果表明：改性材的弦向、径向和体积干缩率与素材相比均有不同程度的下降；改性材的弦向、径向和体积湿胀率与素材相比也均有不同程度的下降，但当改性剂浓度超过20％时，下降才较明显；改性材吸水率随改性剂浓度的上升而下降，最大可由改性前的197％下降到改性后的155％；改性材的抗干缩系数（ASE）随改性剂浓度上升而增加，最大可达18．8％。杉木改性材的尺寸稳定性能要明显优于素材。     

Influence of treatment temperature and duration on selected biological, mechanical, physical and optical properties of thermally modified timber

The impact of heat-treatment temperature (180, 200, 210, 220 and 240°C) and various heat-treatment durations on selected biological, mechanical, optical and physical properties of thermally modified timber (TMT) was determined. The suitability of different measures for prediction of the treatment intensity was also investigated. Resistance to impact milling (RIM), lightness L*, equilibrium moisture content (EMC), and antiswelling efficiency (ASE) were correlated with corresponding fungal resistance achieved by heat treatments. The results show that the decrease in mass by heat treatments is a suitable measurand to describe the treatment intensity, which is a product of treatment temperature and duration, where the impact of temperature is dominant over the impact of time. The properties examined showed a strong reciprocally proportional relationship with the decrease in mass. Different correlations were found for the various treatment temperatures: the higher the temperature applied, the lower the decrease in mass required for an equivalent improvement in certain wood properties, e.g. biological durability, EMC and dimensional stability. However, mass loss by Poria placenta correlated well with RIM, lightness L*, EMC and ASE of the different heat-treated specimens, depending on the heat-treatment temperature. Consequently, a reliable estimation of improved fungal resistance of TMT, as well as quality control of TMT in general, requires certain process information.     

几种分离技术在农药残留分析中的应用

本文介绍了样品现代前处理技术加速溶剂萃取(ASE)、超临界流体萃取(SFE)、固相萃取(SPE)、固相微萃取(SPME)、凝胶渗透色谱(GPC)的原理及其在农药残留分析中应用情况。     

含硫沉积物中有机氯农药的样品提取、净化与测定

利用GC-ECD研究了天津污灌区沉积物中16种有机氯农药的提取和测定方法。考察了加速溶剂提取的提取条件、样品净化方法和GC-ECD的测定条件。结果表明,在125℃用1∶1正己烷和二氯甲烷提取静态10min,2次循环,磺化,过florisil层析柱,铜粉脱硫后用GC-ECD测定可以得到很好的效果。主要7种物质的方法回收率在75%～91%之间,重现性较好。天津代表性沉积物中7种主要OCPs的实测浓度在0.380～2.093mg·kg-1范围内。     

海葡萄蕨藻多糖ASE提取工艺研究

为研究海葡萄多糖提取的工艺条件,以蒽酮-浓硫酸法测定粗多糖中的总糖含量为指标,采用正交试验L9(33)结合加速溶剂萃取技术(ASE)对海葡萄多糖提取工艺进行优化.结果显示,海葡萄多糖的最佳提取工艺条件为温度120℃、静态提取2次、每次35 min,提取温度对多糖提取率具有极显著性影响.在最优条件下,海葡萄多糖得率为51.03(±0.62)％,与传统水提醇沉提取法(多糖提取率30.21％)相比,该提取工艺具有操作简便、缩短提取时间、节能耗、多糖得率高等优点,是一种快速经济实用的新型工艺.     

应用高效液相色谱法同时测定烟草中6种多酚类化合物

应用高压液相色谱法同时测定了烟草中6种多酚类化合物,该方法采用二极阵列管检测器的3个通道同时采集数据,保证了测试结果的可靠性.使用弱酸性的溶液作流动相,梯度洗脱条件下,6种化合物得到了很好的分离.采用加速溶剂萃取(ASE)仪,在40℃下以含0.5%抗坏血酸的无水甲醇为萃取剂,既避免了多酚的分解,又保证了它们被提取的效率.提取液经过实验室自制净化柱的净化,有效地去除了干扰物对分析测试的影响及提取的亲脂性化合物对分离柱的影响.本试验所述的系列方法回收率高于84%,相对标准偏差低于5%,适于烟草中多酚化合物的测定.     

ASE及GPC技术在测定对羟基苯甲酸酯类防腐剂中的应用

建立了一种适用于食品中对羟基苯甲酸酯类(甲酯、乙酯、丙酯、丁酯)等常见防腐剂测定的简便快速的前处理方法。样品用环己烷/乙酸乙酯混合液(1∶1,V/V)提取,通过加速溶剂萃取仪(ASE)萃取,萃取液经凝胶渗透色谱仪(GPC)净化后,进GC-FID检测。4种对羟基苯甲酸酯在0.5~40.0 mg.kg-1范围内呈良好的线性关系,对于5.0 g的样品检出限分别为0.5 mg.kg-1、0.5 mg.kg-1、0.6 mg.kg-1、0.6 mg.kg-1(S/N≥3),添加平均回收率85%~110%,RSD10%。与国标前处理方法对照,本法具有灵敏度高、选择性好、回收率高、可靠性强、简单快捷等优点。     

基于．NET的高校工资查询系统的设计与实现

用ASP．NET结合SQLServer2005数据库管理系统开发了一套高校工资查询系统。该系统可实现教职工在线设置／修改密码、查询工资;财务管理人员可实现添加、修改或删除人员或工资信息。针对每个月都需要更新大量工资信息的实际,系统实现了远程上传Excel工资数据,并导入数据库的功能。该系统操作简单,技术实用,方便了教职工查询工资的同时,提高了财务人员的工作效率。