思茅松阻燃胶合板的制备和性能

思茅松Pinus kesiya是云南的主要用材树种之一,主要用于制备胶合板。为了进一步改善思茅松胶合板的综合性能,提高其使用安全性,主要研究了思茅松单板的阻燃浸渍性,思茅松阻燃胶合板的力学性能和燃烧性能。研究结果表明:在阻燃剂质量分数为120 gkg－1,浸渍温度100 ℃的条件下,随着阻燃剂浸渍时间从1 h增加到5 h,思茅松单板的浸渍率依次增加;绝干单板的浸渍率要高于气干单板的浸渍率;并且4种不同阻燃剂（FR-A,FR-B,FR-C和FR-D）在相同的条件下其浸渍率各不相同,与阻燃剂的化学成分及其对木材的吸附性有关。另外,随着浸渍时间从1 h增加到5 h,单板阻燃剂浸渍率提高,胶合强度降低,氧指数和烟密度增加。当阻燃剂为FR-A时,胶合强度从0.97 MPa降低到0.73 MPa,氧指数从41.89%增加到64.88%,烟密度等级从1.20增加到10.95;而阻燃剂为FR?鄄B时,胶合强度从1.09 MPa降低到1.07 MPa,氧指数从42.35%增加到44.11%,烟密度等级从10.57增加到17.95。可见在胶合板中添加阻燃剂后会对板材的力学性能产生不利影响,但会改善板材的阻燃性;并且不同的阻燃剂对板材的力学性能和燃烧性能可产生不同的影响。此外,加入阻燃剂后,板材的发烟性提高,为了改善其发烟性,可进一步在胶合板中加入抑烟剂。利用阻燃剂来改善思茅松胶合板的阻燃性能是可行的,但阻燃剂的种类和配方尚需进一步进行研究和探索。表4参11     

山核桃等3类果蓬原料机制炭燃烧性能分析

利用TG-DTG-DSC热分析联用技术,对油茶Camellia oleifera,板栗Castanea mollissima和山核桃Carya cathayensis等3类果蓬制备的机制炭燃烧性能分析结果表明:3类果蓬机制炭燃烧失重开始所需的温度分别为435.4,448.1和412.3 ℃,较马尾松Pinus massoniana和杉木Cunninghamia lanceolata为原料制备的普通机制炭519.8 ℃低71.7~107.5 ℃,燃烧速率曲线峰值和峰值温度、放热曲线的峰值和相应的峰值温度均表现为普通机制炭＞油茶、板栗果蓬机制炭＞山核桃果蓬机制炭,即果蓬类机制炭可燃性优于普通机制炭;着火温度、最大释热量、最大燃烧速率和着火后最大失重速率及其相应温度5个参数大小排列均呈现为普通机制炭＞板栗果蓬机制炭＞油茶果蓬机制炭＞山核桃果蓬机制炭,其中山核桃果蓬机制炭着火温度408.6 ℃,较普通机制炭504.4 ℃低95.8 ℃,普通机制炭最大释热量95.12 Wg－1,比最大释热量分别为87.76,92.07,84.82 Wg－1的果蓬类机制炭高3.05 ~ 10.30 Wg－1,即生产中可以通过调节果蓬原料的添加量制备不同着火温度和燃烧特性的机制炭。图4表2参12     

农机用户节油六法

<正>柴油机的节油,除了提高柴油机本身的技术状态,从机械部分内在节油外,更要注重储油、加油和净油等外在的节油,潜力是很大的。1防止储油桶(缸)渗漏和挥发柴油有严重的渗     

春耕农机节油降耗六要点

<正>1作业前做好准备工作①制订小段作业计划。②全面检查机具技术状态,按农业技术要求和机务技术要求进行安装、调整,如调节器整株行距、播量划印器等,并实地操作试验,将隐患排除在作业之前。③查看地块和道路,视土质、墒情和地温等情况,确定作业时间和方法,合理划区,减少地头转弯。④备足油、物料。2合理运用农机具①合理编组,尽可能并联多台农具作业。②使用要得当,尽量减少拖拉机进地次数,抓住墒情作业,严格按农业耕作技术要求办事,保证作业质量。③正确操作。拖拉机的启动、驾驶、停车、熄火,以及驾驶中的转向、变速;制动、供油等各项操作,都与油耗有直接关系,要保持启动装置完好,     

黄河内蒙古包头段水体氨氮污染状况分析

通过对黄河包头段氨氮污染状况水质监测数据的时间和空间分布进行分析,发现黄河包头段氨氮污染近几年呈逐年下降的趋势,但污染还是较为严重;一年中6~10月氨氮含量较低,其他月份氨氮含量增高,且氨氮含量随温度的降低而增高。     

生物质燃烧技术的研究进展

生物质燃烧技术是生物质能转化利用途径研究较成熟的一种主要方式。从影响生物质燃烧特性的因素出发,综述了生物质燃料组分、理化特性和运行条件在生物质燃烧技术中的作用,介绍了生物质燃烧过程的动力学模拟研究现状,对生物质燃烧过程中存在的问题进行了总结和探讨,并对今后生物质燃烧技术的发展进行了展望。     

高能易燃蜂窝煤制作工艺

一、产品特点:高能易燃蜂窝煤仍以煤作原料,但加入少量助燃剂后,使煤的燃烧性能发生根本的变化,与传统方法生产的蜂窝煤相比,具有以下五大优点。1.节能。使用传统方法生产,1吨原煤只能加工蜂窝煤2300～2500个,而采用高能速燃蜂窝煤技术生产,每吨原煤可加工优质蜂窝煤5000个以上(大小相同),可节省原煤50%以上。     

The Study on the Effects of Chinese Herbal Mixtures on Growth, Activity of Post-Ruminal Digestive Enzymes and Serum Antioxidant Status of Beef Cattle

Sixteen Limousin×Luxi crossbred beef cattle [099.4±8.67) kg] were used to evaluate the effects of Chinese herbal mixtures (CHM) on growth, activities of post-ruminal digestive enzymes and serum antioxidant status of beef cattle. Treatments were control (no CHM supplementation) and three formulations of CHM (CHM-A, CHM-B and CHM-C) that were arranged as completely randomized design. The calves were fed in indoor individual feeding barn with total mixed ration for 90 d.The CHM-A, CHM-B, and CHM-C was incorporated into the diet at the level of 20 g kg-1 DM (dry matter) of concentrate.The cattle were weighted at the beginning, at the end and every 15 d between to determine growth rate. Blood sample was taken every 30 d to analyze activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) and concentration of malondialdehyde (MDA). The cattle were slaughtered at the end of experiment and chymus samples from various section of the post-ruminal digestive tract were collected to analyze enzymes activities. All cattle had similar average daily gain, but cattle supplemented with CHM-A tended faster growth (P=0.08) compared to the control and other CHM treatments. Supplementation of CHM did not affect Ph of chymus in any section of the post-ruminal digestive tract.Activities of pepsin, trypsin, chymotrypsin, and lipase in chymus samples were enhanced (P<0.05) to various extents by supplementation of CHM-A, CHM-B, and CHM-C depending on the enzymes and the site of the digestive tract. Amylase activity was increased only by CHM-A and CHM-C from chymus sample collected at the ileum. Supplementation of CHM-A and CHM-B reduced (P<0.05) concentration of MDA, but did not affect GSH-PX activity in the serum of cattle throughout the entire experimental period. Cattle supplemented with CHM-B also had higher (P<0.05) T-SOD activity in the serum at day 30 and 60 as compared with the control and the other two CHM treatments. Chinese herbal mixtures supplemented at the levels of 20 g kg-1 DM of concentrate increased post-ruminal digestive enzymes activity and enhanced serum antioxidant status. Inclusion of CHM-A and CHM-B in the diet may be favourable for ruminant production.     

简述拖拉机常见故障与排除

随着国家购机补贴惠农致策的实施,拖拉机已经走进了千家万户。如何做到安全驾驶,这就要求每一个驾驶员除掌握必要的操作技巧外,还应该保证拖拉机的技术状态良好,并了解拖拉机在使用过程中常见的故障以及排除方法。