科创中国

The classical natural coordinate modeling method which removes the Euler angles and Euler parameters from the governing equations is particularly suitable for the sensitivity analysis and optimization of multibody systems. However, the formulation has so many principles in choosing the generalized coordinates that it hinders the implementation of modeling automation. A first order direct sensitivity analysis approach to multibody systems formulated with novel natural coordinates is presented. Firstly, a new selection method for natural coordinate is developed. The method introduces 12 coordinates to describe the position and orientation of a spatial object. On the basis of the proposed natural coordinates, rigid constraint conditions, the basic constraint elements as well as the initial conditions for the governing equations are derived. Considering the characteristics of the governing equations, the newly proposed generalized-α integration method is used and the corresponding algorithm flowchart is discussed. The objective function, the detailed analysis process of first order direct sensitivity analysis and related solving strategy are provided based on the previous modeling system. Finally, in order to verify the validity and accuracy of the method presented, the sensitivity analysis of a planar spinner-slider mechanism and a spatial crank-slider mechanism are conducted. The test results agree well with that of the finite difference method, and the maximum absolute deviation of the results is less than 3%. The proposed approach is not only convenient for automatic modeling, but also helpful for the reduction of the complexity of sensitivity analysis, which provides a practical and effective way to obtain sensitivity for the optimization problems of multibody systems.

目的 对绿色产色链霉菌阿维拉霉素高产菌株进行推理选育.方法 采用60Co γ射线诱变、NTG诱变等手段,以阿维拉霉素、链霉素、2-脱氧-D-葡萄糖和α-氨基丁酸抗性为筛选压力,得到3株较高产突变菌株#1316、#1317、#1319;并以此为亲本,进行基因组重排筛选.通过扫描电镜等方法对高产突变株A11-13的菌落、孢子丝、分生孢子的分化特征和生长特性进行了研究,并进行50L发酵罐上发酵试验及发酵产物的验证.结果 得到一株阿维拉霉素高产菌株A11-13,发酵单位达到1318.7mg/L,是原始菌株A-05和突变株#1317产率的202.9倍和9.18倍.50L发酵罐上试验中阿维拉霉菌发酵单位达到1773.9mg/L.该菌株气生菌丝较为粗壮,表面光滑,且孢子量很多,孢子为直径约0.7μm*1.5μm的长椭圆形,与出发菌株存在明显区别.结论 菌株A11-13表现出较高的工业应用潜力.抗生素发酵中形态特征与产率高低有一定的关联性.

探讨生长分化因子-9(GDF-9)及其mRNA在高雄激素多囊卵巢综合征(PCOS)大鼠模型中的表达.方法:43只雌性sD大鼠随机分组,实验组大鼠皮下注射脱氢表雄酮建立PCOS动物模型;采用放射免疫法测定血清性激素水平,结合大鼠模型卵巢组织HE染色的病理结构改变进行模型验证;采用免疫组织化学法检测大鼠卵巢组织GDF-9表达及定位,蛋白印迹法进-步观察GDF-9表达变化;逆转录PCR法检测GDF-9mRNA表达.结果:血清性激素水平及HE染色病理结果均提示模型建立成功.免疫组织化学结果显示实验组卵泡中GDF-9表达增强,卵巢间质GDF-9表达下降,实验组和对照组间卵泡和间质灰度值差异均有统计学意义(P〈0.05).蛋白印迹检测及PCR结果提示实验组GDF-9蛋白表达下降,而GDF-9mRNA表达与对照组比较无差异.结论:GDF-9表达及分布改变可能是PCOS发生发展的重要原因.