On the Relative Twist Formula of l-adic Sheaves

We propose a conjecture on the relative twist formula of l-adic sheaves, which can be viewed as a generalization of Kato—Saito's conjecture. We verify this conjecture under some transversal assumptions. We also define a relative cohomological characteristic class and prove that its formation is compatible with proper push-forward. A conjectural relation is also given between the relative twist formula and the relative cohomological characteristic class.     

基于特征圆单目视觉的飞机舵面角位移标定技术

提出了一种基于特征圆单目视觉的非接触式飞机舵面角位移标定技术。用一台数码摄像机对固定在飞机舵面上的特征圆进行拍照,经数字图像处理后确定五个特征点的坐标,利用针孔成像和射影变换原理建立物像空间坐标解算模型,计算出特征圆的法线相对方向和圆心的相对位置,舵面角位移由该圆的法线方向确定。仿真结果表明,该方法具有标定过程简单、实时、快速和准确的特点,标定精度可达到0.1°。该技术也可用于航天器上实时测量交会对接时的相对位姿参数。     

Interface trap-induced negative differential resistance in nMOSFET with floating source

Interface trap can act as the generation center in device to induce a very weak generation current. We observed the negative differential resistance NDR of this generation current I_D in nMOSFET with the floating source. It originates from that the generation function of interface trap is enabled and then is shut down in turn as increasing the drain voltage. This change relies on the interaction among the interface trap energy-level and the electron's Fermi-levels of drain and source under the floating source condition. It is found that the peak-to-valley ratio of I_D is beyond 30.     

Antioxidant,Antimicrobial, and Insecticidal Properties of a Chemically Characterized Essential Oil from the Leaves of Dittrichia viscosa L.

Since some synthetic insecticides cause damage to human health, compounds in plants can be viable alternatives to conventional synthetic pesticides. Dittrichia viscosa L. is a perennial Mediterranean plant known to possess biological activities, including insecticidal properties. The chemical composition of an essential oil (EOD) from D. viscosa, as well as its antioxidant, antimicrobial, and insecticidal effects on the cowpea weevil (Callosobruchus maculatus) were determined. Forty-one volatile compounds were identified in EOD, which accounted for 97.5% of its constituents. Bornyl acetate (41%) was a major compound, followed by borneol (9.3%), α-amorphene (6.6%), and caryophyllene oxide (5.7%). EOD exhibited significant antioxidant activity in all tests performed, with an IC₅₀ of 1.30 ± 0.05 mg/mL in the DPPH test and an EC₅₀ equal to 36.0 ± 2.5 mg/mL in the FRAP assay. In the phosphor-molybdenum test, EOD results ranged from 39.81 ± 0.7 to 192.1 ± 0.8 mg AAE/g E. EOD was active on E. coli (9.5 ± 0.5 mm), S. aureus (31.0 ± 1.5 mm), C. albicans (20.4 ± 0.5 mm), and S. cerevisiae (28.0 ± 1.0 mm), with MICs ranging from 0.1 mg/mL to 3.3 mg/mL. We found that 1 µL of EOD caused 97.5 ± 5.0% insect mortality after 96 h in the inhalation test and 60.0 ± 8.3% in the ingestion assay. The median lethal concentration (LC₅₀) was 7.8 ± 0.3 μL EO/L, while the effective concentration in the ingestion test (LC₅₀) was 15.0 ± 2.1 μL EO/L. We found that 20 µL of EOD caused a reduction of more than 91% of C. maculatus laid eggs.     

圆管流动水击压力波测量及水力计算

为探索水击现象的物理过程和机理,研制了自循环定常流动管路瞬态特性计算机控制试验装置,并利用该装置进行圆管流动水击压力波实验测量。用12只扩散硅压力传感器测定圆管流动水击压力波瞬态分布及最大、最小压力值,由试验数据拟合出水击波波形,揭示了水击压力波传播方式、特性及衰减规律。通过分析随机捕捉测量技术方法,理论上推断出测量数据达到可信精度。在归纳分析试验数据基础上,得出最大压力随关阀时间的关系曲线,对圆管流动直接水击等概念进行了探讨,用数值分析方法拟合出水击最大压力水力计算修正方程式。     

蓖麻油聚氧乙烯醚水基润滑液摩擦学特性研究

本文以蓖麻油聚氧乙烯醚水基润滑液为研究对象,分别使用润滑膜厚度测量仪、微摩擦试验机和四球摩擦试验机对其成膜特性、摩擦磨损特性和抗磨极压特性进行了系统的研究,并用扫描电子显微镜和能量色散光谱仪对摩擦磨损机制进行了分析。结果表明：蓖麻油聚氧乙烯醚提高了纯水的成膜能力,能够在钢-铝摩擦副形成有效的润滑膜,起到良好的减摩抗磨效果。随着浓度的增大,对钢-铝摩擦副的减摩抗磨性能和四球摩擦试验的抗磨极压性能都得到了提高。     

关于格的卡氏积的特征多项式和几何性

利用格L_i(i=1,2)的性质研究了它们的卡氏积L=L_1×L_2的性质,得到了L的秩函数、Mbius函数和特征多项式,并且由L_i的几何性证明了L的几何性.     

ALGEBROIDAL FUNCTION AND ITS DERIVED FUNCTION IN UNIT CIRCULAR DISC

In this article,the authors define the derived function of an algeboidal function in the unit disc,prove it is an algabriodal function,and study the order of algebroidal function and that of its derived function in unit circular disc.     

微分学中构造函数的新方法

结合实例将常微分方程中的首次积分和特征方程理论应用于微分学中函数的构造,从而使之有章可循.     

四元数矩阵理论中的几个概念间的关系

本文指出并改正文［１］中的错误，给出弱特征多项式［２］与重特征多项式［３］间的显式关系，同时也给出行列式［２］与重行列式［４］间的显式关系，最后讨论了左特征值、右特征值、特征值和特征根之间的关系及最小多项式与弱特征多项式根之间的关系．