腐朽过程中毛竹主要化学成分的变化

以毛竹为原料,选择1种白腐菌和2种褐腐菌对竹材进行腐朽试验,利用X射线衍射和傅里叶红外光谱等手段,测定竹材的失重率、相对结晶度和化学官能团。结果表明,随腐朽时间的延长,竹材的失重率不断增加,结晶度不断下降。通过对腐朽竹材主要官能团的观察,发现白腐菌的侵蚀能造成竹材主成分的分解,其中对木质素的分解能力更强。褐腐菌的侵蚀主要破坏竹材综纤维素。     

五种丛生竹天然抗白蚁性能研究

笔者以梁山慈竹、龙竹、勃氏甜龙竹、撑绿杂交竹、硬头黄竹为研究对象,参考国家标准GB/T 18260-2000对不同竹种、不同竹龄、不同部位的竹材进行了天然抗白蚁性能比较,以筛选抗蛀性能较好的竹材.结果表明:五种丛生竹的竹材均不具有天然抗白蚁性能;竹龄对梁山慈竹抗白蚁性能影响显著,随竹龄增加其失重率减小,竹材部位对其影响不显著.竹龄在3年以上的梁山慈竹的天然抗白蚁性优于1年和2年的;竹龄对龙竹抗白蚁性能影响不显著,竹材部位对其影响极显著,竹材上部与中下部差异显著,竹材上部失重率大于中下部;五种竹材被白蚁蛀蚀的失重率大小顺序为:梁山慈竹失重率最小,其次为勃氏甜龙竹、龙竹和硬头黄竹,撑绿杂交竹的抗白蚁性能最差、失重率最高;去竹青竹黄的龙竹试样失重率高于原竹试样,说明竹青竹黄对白蚁蛀蚀有一定防护作用.     

防腐后处理工艺对竹集成材耐久性的影响

以两种水载铜基防腐剂季铵铜和铜唑对竹集成材进行防腐处理,分析了不同药剂和载药量对竹集成材耐腐性能的影响,以及不同干燥温度对处理材抗流失性能的影响,以筛选适宜的竹集成材防腐后处理工艺,显著提高处理材的耐久性.结果表明,经防腐处理后,竹集成材的耐腐性能大幅度提高,当季铵铜载药量≥2.6 kg/m3或铜唑载药量≥1.3 kg/m3时,竹集成材可以达到强耐腐等级;处理材的铜固着率随着载药量的增加而提高,不同干燥温度对铜的抗流失性能影响不显著.总体上看,防腐后处理工艺能够满足提高竹集成材耐久性能的要求,但其防腐剂的抗流失性能有待提高.     

Experiment analysis on dissolution characteristics of rock salt on the effect of triaxial stress

Rock salt underground storage is an important way of energy reserves. The research of rock salt dissolution characteristics under triaxial stress provides theoretical basis for shape control,security building of rock salt underground storage in the process of making aqueous cavity. The dissolution characteristics of rock salt specimens experiment with triaxial testing machine under triaxial stress,through a lot of rock salt dissolution tests,finds that dissolution characteristics of rock salt change remarkably under stress. Analyzing the relationship between the stress of rock salt specimen with the water hole and sample external axial compression or confining pressure,equivalent stress is adopted to describe the stress distribution of the running water hole wall. Triaxial stress and dissolution coupling experiment on the different confining pressure is carried out to analysis the variation between rock salt dissolution rate and equivalent stress under different confining pressures. The results show that rock salt dissolution rate decreases first and then rapid increases with the increase of equivalent stress. The main impact of the stress for rock salt dissolution rate is that cracks development and corrosion area in rock salt specimen are changed because of the triaxial stress loading. Dissolution rate reduces as a result of corrosion area decreasing (crack closure) in the elastic stage,however dissolution rate increases because of corrosion area increasing (crack development) in the plastic stage.     

Experiments on cleaning tunnels with dry ice

Vehicle exhaust,dust and grease in tunnels are hard to be degraded,thus there will be more and more pollutants and the traffic safety will be influenced. Therefore,regularly cleaning tunnels is important for guaranteeing the traffic safety in tunnels. A tunnel cleaning method with dry ice is proposed,and a model of dry ice cleaning tunnel is developed based on the physical,chemical and cleaning properties of dry ice. Some experiments about the surface hole,surface temperature and the uniaxial compressive strength of the concrete are conducted. The surface damage and the compressive strength of the concrete is researched after the cleaning process. The test results show that：the dry ice cleaning method can thoroughly clean the surface of concrete;the surface damage and the compressive strength is little influence by the temperature and dry ice micro blasting. So dry ice cleaning method can be used for cleaning tunnel.     

西藏核桃研究进展及发展趋势

在综述西藏核桃的起源、分布、坚果特性、遗传多样性及引种栽培等方面的研究进展的基础上,结合西藏核桃发展需求,探讨西藏核桃的发展趋势,可为西藏核桃产业的可持续发展和进一步的研究工作提供参考。     

森林生态系统管理理论框架下的桉树人工林可持续经营视角

森林生态系统管理是实现森林可持续经营的一条生态途径。桉树是我国华南地区主要人工林树种,种植面积达360万hm2,为社会发展和国家建设提供大量木材,推进生态文明。在桉树可持续发展面临诸多挑战的背景下,综述生态系统管理的思想产生、理论概念、内涵和实施步骤,融合生态系统管理原则和桉树人工林栽培管理技术,提出桉树人工林可持续发展与管理对策,以期为桉树人工林经营者、林业科研工作者以及政府部门决策者提供参考依据。     

扎赉特旗林业生态建设对林业可持续经营发展的影响

文章通过扎赉特旗林业生态建设的发展现状及发展趋势分析,阐述了林业工程建设的实施对扎赉特旗生态环境的影响和在资源环境可持续发展中的重要作用。     

玉米黄改系耐旱性材料筛选与鉴定方法研究

在正常水分、花期干旱、全生育期干旱3种水分条件下,对25份玉米黄改系材料和亲本黄早四进行耐旱性鉴定并筛选耐旱材料。结果表明,花期干旱胁迫和全生育期干旱胁迫条件均可进行耐旱性鉴定。在干旱胁迫条件下,穗部性状(单穗穗重、单穗粒重、百粒重和耐旱系数)、粒型性状(粒长)和花期性状(开花吐丝间隔,ASI)能够作为耐旱筛选性状,株型性状作为筛选的参考性状,粒型性状(粒宽和粒厚)不能作为筛选性状。根据干旱胁迫的筛选,获得9份黄改系耐旱性材料。     

茶树雌蕊总蛋白质双向电泳分离体系的建立

为建立一套适合茶树雌蕊总蛋白质分离的双向电泳体系,对茶树雌蕊总蛋白的提取方法、SDS-PAGE凝胶浓度、聚焦条件和IPG胶条pH范围等进行了比较优化。结果表明,TCA/丙酮-clean up kit法提取总蛋白,用17 cm pH 5~8 IPG胶条,13%SDS-聚丙烯酰胺凝胶进行分离,用考马斯亮蓝R250染色,可以获得清晰、分辨率高、重复性好的双向电泳图谱,共检测到约1 200个蛋白点,主要分布在pH 5~8,相对分子量14~117 kD范围内,碱性蛋白得到有效分离,可以满足茶树雌蕊的蛋白组学分析和研究。