竹丝炭化时间对风力发电机叶片阻燃性能的影响

风力发电站常常安装在偏远的海岛、高山或沙漠地区,叶片在使用过程中常受到高温、闪电、野火等等不利因素的影响而烧损,因此,风电叶片材料阻燃性能的选择就显得十分重要.采用HRR3热释放率系统、HC-2氧指数测定仪等仪器,测定并分析经由不同炭化时间处理的竹丝制造的竹增强复合材料的阻燃性能.结果表明:竹丝经10 min炭化处理制造的竹增强复合材料,试件在HRR3热释放率系统测试实验中产生的热释放量峰值最低(99.44 kw/m2),且在5 min内总热释放量最低(339.15 kW·min/m2),氧指数值最高(52),其阻燃性能较好.     

高温热处理木材工艺的初步研究

以我国杉木木材为试验材料,采用自制小型热处理木材试验装置进行了高温热处理木材工艺试验.结果表明,下述工艺切实可行:待处理木材的含水率应控制在15%以内;在温度升高与高温干燥阶段,迅速升温至100℃,再缓慢升温到130℃干燥到绝干,再迅速升温到热处理目标温度,目标温度一般应控制在180-220℃范围内;保温处理时间根据需要确定,一般为2～4h;在处理过程中应适当喷蒸.处理终了时,降温到80℃,调整含水率到4%～8%,出窑.热处理后的木材具有高尺寸稳定性,可广泛应用于室外建筑、室内装修.     

竹材在不同介质中加热处理后的强度变异

在竹产品加工过程中,为改变色泽,竹坯材需在不同介质中加热处理,并因此引起竹材在强度性能上的差异。本研究针对毛竹(phyllostachs pubescens)在生产工艺中经不同介质中加热处理后的主要强度作了测试与变异分析,发现竹材经漂煮工艺后其密度和力学性能有所提高,经碳化工艺后则有所下降。     

In vitro degradation of phytate and lower inositol phosphates in soaked diets and feedstuffs

A series of in vitro experiments simulating liquid feeding were performed to evaluate the effect of microbial phytase addition, heat-treatment and soaking time on degradation of phytate and lower inositol phosphates when soaking compound wheat/soybean meal diets or the single feedstuffs wheat or soybean meal. The effect of phytase addition on phytate degradation was greatest in soybean meal, almost intermediate for wheat/soybean meal diets and not detectable in wheat, which might be due to a better accessibility to phytate in soybean meal compared with wheat. Heat-treatment seemed to enhance the accessibility between phytase and phytate, whereby phytate degradation was stimulated. Additionally, it was shown that wheat phytase is able to stimulate degradation of phytate in soybean meal. Independent of treatment, the amount of IP₅–IP₂ was extremely small in relation to phytate in both wheat and soybean meal, indicating that when one phosphate group is removed from the phytate complex, degradation of IP₅–IP₂ is completed. Consequently, it is anticipated that liquid feeding might result in a higher digestibility of plant P compared with dry feeding of pigs.     

补饲热处理大麦对牛肉品质的影响

[目的]研究补饲热处理大麦对牛肉品质的影响。[方法]选用12头体重相近的健康延边黄牛(阉牛),随机分为试验组和对照组,每组6头。饲喂5个月后,测定牛肉品质。[结果]补饲热处理大麦可显著提高牛肉中脂肪含量(P<0.05),显著减缓贮藏期间牛肉pH值、TBARS值的升高(P<0.05),改善牛肉肉质和口感,但对牛肉在贮藏期间颜色变化影响不显著(P>0.05)。[结论]补饲热处理大麦可提高牛肉品质,延长贮藏时间。     

杨木单板炭化处理工艺试验

使用水蒸气作为保护气体,在170-210℃温度下对杨木单板进行2.0-5.0 h炭化处理试验.结果表明,单板颜色变深,呈褐色,主波长范围为592.4-594.1 nm,兴奋纯度在30.8%-48.9%范围之内;力学性能衰减较大,抗拉强度下降了52.3%;尺寸稳定性有提高,24 h吸水厚度膨胀率平均仅为0.56%;胶合性能随炭化温度的升高和炭化时间的延长而降低,适宜的炭化温度为180-185℃,炭化时间为3.0-3.5 h.     

Effect of heat-treatment on stretch of poly(trimethylene terephthalate) woven fabric

The properties of a woven fabric made of poly(trimethylene terephthalate) (PTT) were investigated. The PTT fabric of draw textured yarn (DTY) showed excellent stretch as good as a fabric containing spandex. However, the unique stretch of the PTT fabric reduced dramatically by simple heat-treatment even at as low as 80 °C. To understand the phenomenon, the crimp rigidity of the DTY was observed by SEM. It was found that the drastic reduction of stretch was caused by irreversible uncrimping of PTT DTY after heat-treatment. Conclusively, it is of importance to optimize the texturing conditions for PTT DTY to make the crimp more stable.     

超高温热处理对柞木地板尺寸稳定性的影响

采用窑式常压过热蒸汽方法对栎木地板坯料进行超高温热处理,研究了相对湿度在40%～90%变化范围内,热处理工艺对栎木地板尺寸稳定性的影响。结果表明：热处理并未显著减小木材干缩系数,但能显著减小使用环境温湿度变化对木材含水率变化的影响,从而提高栎木地板使用时的稳定性。为满足地热采暖使用条件,宜采用190℃热处理温度。     

热处理对百合种球根螨防治效果的研究

带螨百合种球在38~42℃水中热处理1.0~5.0 h,观察其对根螨的防治效果及对后期生长发育的影响。结果表明,热水处理百合种球控制根螨效果显著。40℃是百合种球热处理除螨高温致死的临界点,40℃处理≥2.0 h,根螨致死率为100%;随温度升高处理时间缩短,但种球褐变率提高,热伤害加剧;39~41℃处理2.0 h,种球的发芽率和株高显著降低。因此,40℃处理2 h为百合种球除螨最佳处理积温。     

齿轮热处理缺陷分析

对林业机械中广泛应用的硬齿面齿轮在服役条件下出现断裂，过量磨损，变形等主要缺陷进行了较系统的分析，提出了改善齿轮必备机械性能的方法，在实际生产中具有一定的参考价值。