Z170F型柴油机配机动水稻插秧机的改进

Z170F型柴油机与机动水稻插秧机合理匹配,选取合适速比,减小振动,隔振,改进冲压件的结构,最大限度发挥机动插秧的效率。     

用原位有机改性法制备的溴化丁基橡胶／蒙脱土复合材料的性能

采用原位有机改性法制备了溴化丁基橡胶(BIIR)/蒙脱土(MMT)复合材料,并对其硫化特性和力学性能进行了研究,用X射线衍射仪时复合材料中MMT的层间距进行了表征,并与钠基蒙脱土(Na-MMT)、有机蒙脱土(OMMT)和BIIR形成的复合材料进行了对比.结果表明,用原位有机改性法制备的BIIR/MMT复合材料的硫化特性和力学性能优于BIIR/Na/MMT复合材料,甚至优于BIIR/OMMT复合材料;采用原位有机改性法,可使BIIR/MMT体系中MMT的插层效果明显改善.     

Further Study on a Virtual Age Repair Model

A new virtual age repair model with non-uniform aging speed is presented on the basis of Kijima classical virtual age repair models which can be viewed as of uniform aging nature. In this model are included three types, of perfect, of imperfect and of minimal, all having a non-uniform aging speed. Formulas of expected count of repair and length of working time of these three models are derived, and numerical examples are also given to illustrate and verify obtained theoretical indices. As an extended work, a sketchy model of maintenance time of the non-uniform aging virtual age repair model is discussed. Overall, the three models discussed in the paper, each with non-uniform aging speed, are expansions to existing virtual age repair models, relevant formulas given here are new results, and the systems introduced are without the lifetime distribution assumption, all of which may be expected to improve maintenance work.     

Z170F型柴油机配机动水稻插秧机的改进

Z170F型柴油机与机动水稻插秧机合理匹配,选取合适速比,减小振动,隔振,改进冲压件的结构,最大限度发挥机动插秧的效率。     

家兔血浆中甲硝唑的血药浓度测定

采用家兔血浆中甲硝唑的含量测定方法，研究该药不同剂型的药物动力学特点。方法：采用紫外分光光度法测定甲硝唑的血药浓度。结果：标准曲线为C=16．679A 0．7003，线性范围为1．62μg／mL～22．68μg／mL，r=0．9997，方法检出限为1．52μg／mL，回收率为102．86％，RSD为1．2％。结论：该方法准确、精密，适用于甲硝唑在兔体内药物动力学研究。     

爆炸荷载作用下砌体填充墙对RC框架结构损伤破坏的影响

砌体填充墙作为非结构构件在建筑结构抗爆分析中常被忽略,而实际爆炸事故中填充墙多发生严重破坏,从而影响爆炸波的传播及其与结构的相互作用以及结构的损伤破坏等级。基于精细化数值仿真方法评估外部爆炸作用下砌体填充墙对钢筋混凝土(reinforced concrete,RC)框架结构损伤破坏的影响。首先,采用LS-DYNA有限元分析软件分别对典型砌体填充墙和含填充墙RC框架的近区爆炸试验进行复现,验证所采用的填充墙简化微观建模方法、材料本构模型和参数,以及任意拉格朗日欧拉爆炸荷载施加方法和爆炸波-结构流固耦合算法的适用性。进一步结合结构混合单元建模方法,开展了美国联邦应急管理署规定的普通轿车炸弹(454 kg TNT当量)在底层边柱位置爆炸下,6度、7度和8度抗震设防烈度的典型6层纯框架和含填充墙框架结构动力行为的数值仿真分析,考察了爆炸波传播路径,以及结构的动态响应、损伤破坏和抗倒塌机制。结果表明：该工况中填充墙能够有效阻挡爆炸波的传播,作用于目标柱相邻内柱上的超压峰值降低95%,减轻了内部构件的损伤程度;但同时加剧了结构迎爆面的损伤破坏,如3种抗震设防烈度的含填充墙框架目标柱柱中侧向位移较纯...