Molecular cloning and nucleotide sequence of classical swine fever virus strain Shimen

According to the previously published CSFV sequences, 18 paris of partially overlapping primers which span the entire genome of CSFV strain Shimen were designed and synthesized. Each cDNA fragment of strain Shimen was amplified by RT-PCR method from the anticoagulant blood of strain Shimen infected pig. The PCR fragments were cloned into pGEM-T vector respectively and sequenced. The results show that we have obtained the nucleotide sequence of strain Shimen. The viral RNA consists of 12 297 nucleotides including noncoding regions of 373 and 227 bases at the 5′ and 3′ end, respectively, and a single large open reading frame spanning 11 697 nucleotides in the middle, which encodes an amino acid sequence of 3 989 residues with a calculated molecular weight of 437.6×10³. The precisely sequencing of 5′ and 3′ termini is undertaking. Supported by the National Pandeng Project Huang Qianhua: born in 1968. Graduate student     

油菜抗羟脯氨酸突变体的筛选

本文用脯氨酸的类似物羟脯氨酸筛选出经甲基磺酸乙酯（ＥＭＳ）诱变处理的油菜幼胚培养苗的抗羟脯氨酸突变体．抗性系叶片中的绝大多数游离氨基酸的含量都比对照品种“Ｏｒｏ”高,其中游离脯氨酸的含量是“Ｏｒｏ”的２２倍,表明用羟脯氨酸筛选出的突变体植株细胞内的游离氨基酸,特别是游离脯氨酸的含量明显增加．抗性系后代的多种农艺性状试验结果表明,抗性系的产量比对照高３１１％,发病率低３８５％,病情指数下降００９％,说明在油料作物中用羟脯氨酸筛选抗羟脯氨酸的突变体是一种行之有效的方法     

构件预挤压孔的工艺弹塑性和残余应变分析方法

在对工艺应力进行理论分析的基础上,提出了一种构件预挤压孔的工艺弹塑性和残余应变分析方法,通过采用释放残余应变的方法和单光束激光散斑干涉术,分析了三种不同挤压量带孔铝板的预挤压孔对称面上的残余应力,验证了这种分析方法的可行性。     

复合型加载下缺口前应力应变分布的有限元分析

用有限元法计算了一种低合金高强钢缺口试样在非对称四点弯曲加载(Ⅰ Ⅱ型复合加载)下缺口前端的变形和应力应变分布.研究结果表明:纯Ⅰ型加载时,缺口前端变形和塑性区形状对称分布.Ⅰ Ⅱ型复合加载下缺口前端的变形为一侧钝化,另一侧锐化,塑性区顺时针旋转一个角度θ,且θ随Ⅱ型载荷比例的增加而增大.表征缺口前端变形程度的d/b0值,随外加载荷P/Pgy的增加和Ⅱ型载荷比例的增加而增大.另外,对缺口前端最小塑性区路径上的最大切向正应力σθθ、三相应力度σm/和等效塑性应变εp的分布,以及它们随外加载荷P/Pgy和Ⅱ型载荷比例的变化规律也进行了分析,发现缺口试样的开裂遵循最大切应力判据.     

Observation and dydrodynamic analysis of fast-start of yellow catfish (pelteobagrus fulvidraco)

The kinematics and hydrodynamics of the escape response of yellow catfish ( Pelteobagrus fulvidraco ) is investigated.It is observed from digital high-speed camera that all the escape response of yellow catfish is a C-type fast-start, which is characterized by the C-shape of the fish body at the end of the first contraction of the lateral musculature. Based on the analysis of the mass center movement and the performance of the caudal fin, the fast-start process can be divided into two stages: in stage one the fish body rotates rapidly around its mass center and in stage two the fish begins moving straightly. Theoretically, the Weihs' model is employed to obtain the forces, moments and turning angular accelerations acting on the fish during the escape response. The results are in good agreement with the experimental observation. Furthermore, muscle strain at different locations along the body is calculated. At last, the dynamical performance of the escape response is explained.     

挠性结构模型的频域极大似然法辨识

在构建的以压电陶瓷为执行器、电阻式应变片为传感器的挠性悬臂梁物理实验系统基础上,优化设计多正弦辨识输入信号,利用频域极大似然法辨识得到了整个系统的数学模型,并根据该模型进行了数字和物理控制仿真,验证了模型的有效性.良好的控制效果表明:对于挠性结构,频域极大似然法是一种有效的模型辨识方法.     

Implementation of the finite deformation plastic theory-Tensor derivative and metal forging simulation

It has been shown that the traditional small deformation plasticity can be transplanted to the finite deformation plasticity by using the logarithmic strain measure only. In this way, the mathematical problem of how to find the derivative of a tensor function arises. In this paper, a general method for finding the derivative of a tensor function is proposed. Several metal forging examples are given.During the calculation, the mesh regeneration is not even invoked.     

The Effect of Strain Rate on Tensile Properties of Cotton Yarns

The effect of strain rate on tensile properties of cotton yarns is analyzed using the standard linear solid model. The tensile curve, breaking strength and work of rupture of the yarns under different strain rate are calculated. A good correlation exists between the experiment results and theoretical anticipations.     

微小位移的电测法

将非电量测量转化为电量测量可以极大地提高对非电量测量的技术指标。微小位移的精确测量在诸多实验中均有重要的意义，为此，提出了若干种测量微小位移的电测法。     

三向荷载作用下液固耦合平面有限元分析

根据广义平面应变问题具有所有物理量沿某一方向变化为零的特点，针对连续、各向异性两相饱和介质，在变形满足小变形、孔压流满足达西定律、有效应力原理成立的假定下，建立以增量形式的三向荷载作用下液固耦合作用的平面有限元分析方法。