基于道路载荷特征的整车试验场耐久性评价方法

为了获得整车试验场各路况对底盘各零部件的对应考核情况,以国内某整车大型试验场为研究对象,通过将采集到的试验场载荷分解,获得试验场各子路况的载荷时间历程。通过分别以底盘零部件各测点为基准和以试验场各路况为基准对比分析各路况对应各测点的损伤,可得到试验场路况考核表。针对考核表中不同路况考核部件的相似性,对比分析其各路况考核各部件的极值、变程、RMS、损伤,根据分析结果优化此前得到的试验场各路况考核表。此方法可为整车试验场耐久性评价提供一定参考。     

Novel pathotypes of lettuce mosaic virus — breakdown of a durable resistance?

Summary Resistance to lettuce mosaic virus (LMV) is derived either from cv. Gallega (g gene) or the wild accession PI251245 (mo gene). Previous studies indicated that these two genes were identical. Breeders in Europe produced numerous resistant cultivars utilisingg while in the USAmo was used. The resistance has been effective for over 20 years. However, recently there have been reports of LMV isolates causing unusually severe and sometimes necrotic symptoms on cultivars with these resistance genes. Investigations of these severe isolates have distinguished three new pathotypes in addition to the common pathotype (II) and identified a novel dominant gene for resistance. Themo/g genes confer resistance to pathotypes I and II but pathotype III possesses virulence for cultivars withg but not for those withmo. These two genes are therefore not identical but are probably either closely linked genes or alleles. Pathotype IV possesses virulence for all lettuce lines so far tested. Some isolates of this pathotype are seed transmitted in cultivars possessingmo org and have caused severe crop losses in southern France. The durability of the resistance conditioned by these two genes is discussed.     

无粘结预应力混凝土的应用

本文详细介绍了无粘结预应力混凝土的抗震性、耐久性及施工中应注意的事项以及对材料的要求。     

Resistance of bamboo scrimber against white-rot and brown-rot fungi

ABSTRACT

Bamboo scrimber is one of the most emerging structural materials for future building applications and it possesses properties comparable to other natural wood-based engineered materials such as glulam, laminated veneer lumber and cross-laminated timber. The goal of this work was to study the decay resistance of bamboo scrimber against white-rot (Trametes versicolor) and brown-rot fungi (Serpula lacrymans). Bamboo scrimber samples were incubated in petri dishes with the wood-decaying fungi and the weight loss after 12 weeks was measured. The surface morphology of fungal-degraded bamboo scrimber was evaluated using optical microscopy. Based on the percentage weight loss, bamboo scrimber could be classified as highly resistant against bio-deterioration by white and brown-rot fungi.     

柴油机燃用菜籽油的耐久性试验研究

柴油机燃用菜籽油植物油的短期耐久试验证明了植物油可作为一种代用燃料,但同时也暴露出了一系列的问题.试验后观察试验柴油机的主要零部件可看到:燃烧室的表面有大量的积碳、喷油器结焦、气门黏滞、缸套轻微刮伤等现象.这导致了柴油机性能的下降、油耗的升高和经济性的下降.其中,喷油器结焦和气门黏滞是性能下降的主要原因.     

提升现浇混凝土耐久性的相关因素分析

文章将会从优选原材料与质量控制体系,高性能混凝土配台比设计体系,钢筋保护层施工质量控制体系以及混凝土施工质量控制及反馈体系这四个方面分别加以阐述,希望能够得到一些借鉴和参考。     

樟子松热处理材耐久性能的评价

对樟子松热处理材进行室内防霉、防蚁蛀及野外埋地检测,综合评价其耐久性能。结果表明:樟子松热处理材对霉菌、变色菌均无防治效力,不抗白蚁蛀蚀;樟子松热处理材的耐久年限约为3年。     

浅谈提高混凝土耐久性及防腐措施

无论是在土建工程还是在桥梁工程中，混凝土是用途最广、用量最大的建筑材料之一。近百年来，混凝土强度的不断提高成为它主要的发展趋势。     

木质素基超塑化剂的制备及其在砂浆中的应用

来源于木材、麦草、竹子和蔗渣的木质素磺酸钠与三聚氰胺、甲醛和焦亚硫酸钠合成出磺化木质素三聚氰胺甲醛超塑化剂(LSMF).系统研究了LSMF对砂浆减水率、抗压强度、抗折强度和加速碳化深度等应用性能的影响.结果表明,使用麦草基木质素磺酸钠合成出磺化度3.663mmol/g,特性黏度7.24mL/g的LSMF对砂浆的减水增强性能最好.当LSMF掺量为0.7%时,砂浆减水率为21.1%.硬化砂浆28d加速碳化深度为13mm,空白砂浆为34.5mm.掺加LSMF后,硬化砂浆28d抗压强度和抗折强度分别比空白砂浆提高37%和18%.LSMF超塑化剂为木质素高效利用提供了一种新的思路.