低甲醛释放量刨花板用脲醛树脂结构的研究(英文)

本文通过~(13)C NMR研究了脲醛树脂合成新工艺中不同反应阶段时的脲醛树脂的化学结构。研究结果表明脲醛树脂的化学结构主要受甲醛/尿素的摩尔比,pH值、反应温度和反应时间的影响。对脲醛树脂中主要的官能团:游离甲醛、亚甲基、亚甲基醚、Uron等相互关系也进行了研究。指出了生产低甲醛释放量,高力学性能刨花板用脲醛树脂中主要官能团的最佳含量。     

Effects of urea formaldehyde foam soil amendment on growth and response to transient water deficit stress of potted Flindersia schottiana saplings

Hydrocell™is a urea formaldehyde resin foam (UFRF) product used as a soil amendment. It is proposed to improve the physicochemical properties (viz. water relations and aeration) of the plant root zone. Flindersia schottiana is a tree species used in the ornamental horticulture industry. This study investigated the potential of Hydrocell™ [0–50% (v/v) incorporation rates] to promote growth of F. schottiana saplings during containerized nursery production in composted pine bark medium. The growth response of the potted saplings to transient water stress was also assessed. In addition, growth of F. schottiana saplings potted into three different soil types (sand, loam, clay) was assessed in the presence and absence of 30% (v/v) Hydrocell™. Under well-watered conditions in composted pine bark, Hydrocell™ treatments enhanced sapling leaflet numbers, with 30% (v/v) being the most beneficial treatment. However, no consistent significant differential effects of incorporation rate on either plant height or stem diameter were recorded. Extended time to wilting upon withholding irrigation was achieved, with the optimum Hydrocell™ rate being 10% (v/v). Among the three soil types compared, use of 30% (v/v) Hydrocell™ resulted in improved growth of potted F. schottiana saplings in the sand and loam soils, but not in the clay soil. These findings suggest that the UFRF, Hydrocell™, holds limited promise as a soil amendment for trees in the nursery phase. Optimum incorporation rates (v/v) would need to be determined for individual media types, specific irrigation regimes and individual taxa.     

改性三聚氰胺树脂用于实木地板抗菌处理的工艺及性能评价

为使杉木实木地板具有抗菌功能,以三聚氰胺(MF)树脂作为抗菌剂载体,采用真空浸渍工艺处理杉木地板基材,探讨浸渍时间、MF树脂固体含量和相对真空度对杉木试样增重率的影响,并评价地板基材的抗菌效果。结果表明:随着浸渍时间、树脂固体含量、相对真空度的增加,试样的增重率提高,抗菌性亦随之增强。采用试验得出的较佳工艺处理的杉木地板基材,其抗菌性可达到LY/T 1926-2010中规定的Ⅰ级强抗菌级别。     

水产品中甲醛的残留及控制

甲醛是世界卫生组织宣布的一种强烈的致癌物质,在水产品中残留会对人体健康产生危害。综述了水产品中出现甲醛残留的原因,比较了甲醛的定性判定方法、定量检测方法以及样品前处理方法对甲醛测定结果的影响,提出了减少水产品中甲醛的本底含量、控制水产品养殖加工过程中的污染、杜绝水产品中甲醛的人为污染等3项措施来控制水产品中甲醛的残留。     

劣变茶气味的研究——烟气部分的定性定量及其成因

对烟茶劣变气进行了定性定量研究,结果表明:烟茶主要是在加工过程中茶叶不完全燃烧,使类黄酮类、木质素等物质热裂解产生的苯酚、甲苯酚、愈创木酚及其衍生物和少量的稠环化合物等13种物质引起的,其中,苯酚的变化最为明显,以苯酚含量建立的烟气程度计算模式:Y=20.2016 52.4639 1g X与感观审评结果的符合率达93.3％,本研究还探讨了烟气的形成机理及烟茶产生的原因,首次为这种劣变茶的监测提供了依据。     

粒子群电解法降解焦化废水中酚的影响因素研究

通过粒子群电解装置(PEC)对含酚废水进行处理，对影响粒子群的一些基本因素(电解时间、pH值、电流、电压、添加剂和不同填充粒子)进行了试验分析，得出了最佳的操作参数；同时也对PEC装置处理煤制气厂的焦化含酚废水进行了试验验证，为实际进行工业应用提供了可靠依据；还探讨了粒子群电解法降解有机污染物的主要机理。     

E1级防潮型中密度纤维板的工艺因子对甲醛释放量的影响

为了生产符合要求的E1级防潮型中密度纤维板,胶粘剂最好使用三聚氰胺改性的低毒脲醛树脂胶粘剂,三聚氰胺添加量为80 g·kg-1时能满足E1级防潮型中密度纤维板的生产要求.在胶粘剂已定的情况下,施胶量增加可以降低板材甲醛释放量,11%～13%施胶量比较合适;热压温度升高、热压时间延长能明显降低板材中甲醛释放量;随着中密度纤维板厚度增加,板材中甲醛释放量也能降低.本次实验中板材厚度为16 mm时,热压温度190 ℃,热压时间25 s·mm-1是比较合适的.图4表1参7     

一株苯酚降解菌(Alcaligenes faecalis BC2001)的PCR检测及其苯酚降解特性研究

根据苯酚羟化酶基因高度保守序列设计一对该基因的特异引物。采用该特异引物从粪产碱菌BC2001总DNA中扩增一条大小为684 bp的片段。将该DNA片段进行序列分析,发现其与Proteobacterium L-18菌(登录号为:AY346142)的基因序列的同源性为97%。另降解试验表明BC2001菌在pH=6时(质量浓度为500mg.L-1)其生长最佳,而在苯酚质量浓度为300 mg.L-1时也是菌株具降解能力的有效例子。     

低酚棉光子1号杂种一代优势利用研究

低酚棉与低酚棉光子1号品种间杂种一代优势强，品质好，产量高，增产幅度为21．3％～98．8％，是解决低酚棉稳产性与抗逆性差的有效途径。利用低酚光子指示性状，容易鉴别真假杂种，具有广阔的应用前景。     

Dietary protein sources and their effects on faecal odour and the composition of volatile organic compounds in faeces of French Bulldogs

The strong odour of faeces and excessive production of gases in some dog breeds have long been a concern of owners. The pet food industry uses nutritional alternatives, such as high-quality ingredients and additives, to improve the odour of faeces. However, there are still some dog breeds, such as the French Bulldog, that present this problem due to the presence into the large intestine of indigested protein. Therefore, a deeper understanding of the volatile compounds that influence the odour of dog faeces is important. This study aimed to identify changes of faecal odour compounds that are most prevalent in French Bulldogs based on food containing different high-quality protein sources and their effect in sensory analysis. Four maintenance foods with different protein sources were formulated: P, poultry meal food; W, wheat gluten food; PW, poultry meal and wheat gluten food; and PWH, poultry meal, wheat gluten, and hydrolysed protein food. Eight adult French Bulldogs were arranged in a 4x4 Latin square design and adapted to foods for 28 days. Fresh faeces were collected for analysis of volatile organic compounds (VOCs) and sensory analysis. The means were compared by SAS, and statistical significance was indicated by p ≤ 0.05. No adverse effects were observed in the animals regarding VOCs, and a significant difference was observed in two of the 68 compounds identified. The animals fed a P food had higher concentrations of phenol in the faeces, whereas the indole compound was present at higher concentrations in animals fed the W food. P food was associated with higher odour perception during sensory evaluation. In summary, the source of protein in the foods had little impact on the composition of VOCs, and a greater perception of the odour was determined by sensory analysis when foods containing animal protein were administered.