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21.
任伟新 《实验力学》1993,8(2):174-179
本文通过试验研究了35CrMo 合金钢三点弯曲试样疲劳短裂纹的扩展特性;用电测法得到了裂尖处的载荷—应变标定关系。试验结果表明,短裂纹的扩展速率正比于局部应力幅的幂次和裂纹长度,即 da/dN=A(?),可以较好地描述疲劳短裂纹的扩展规律。  相似文献   
22.
With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has brought new opportunities for the development of molecular biotechnology. Reversed micelles represent nano-sized aqueous droplets stabilized by surfactant amphiphiles inside the bulk organic solvents. The entrapped enzymes have enhanced activities under those conditions as suited in the lipid b...  相似文献   
23.
We give more efficient criteria to characterise prime ideal or primary ideal.Further,we obtain the necessary and sufficient conditions that an ideal is prime or primary in real field from the Gr¨obner bases directly.  相似文献   
24.
本文建立了一般卷积算子在函数的第一类间断点处有Gibbs现象的刻画定理,并且给出了某些例子.  相似文献   
25.
本文对ICP-AES法测定氨甲环酸中痕量Pt和Ba的方法进行了研究,着重对氨甲环酸试样的不同分解方法进行了比较,用酸直接分解试样,方法简便,快速,试剂空白低,方法的回收率大于96.2%,相对标准偏差小于5%,准确度及精密度均符合要求,可用于氨甲环酸的生产控制和成品的检验分析。  相似文献   
26.
 运用序列二次规划法设计了靶区光路。由ICF 柱面靶间接驱动实验对多路激光束排布的要求, 建立靶区数学模型, 用本文设计结果构筑光路排布线框实体。该三维线框以特征线代表60路激光驱动光束实体, 以特征线段的转折点代表240面反射镜的空间位置。  相似文献   
27.
文章报道用铂作基体改进剂直接测定全血中铅的石墨炉原子吸收光谱法。同时应用衬钽技术,大大延长了石墨管的使用寿命。该方法准确、简便快速,灵敏度为1.74μg·L~(-1),回收率为96%~103%,变异系数小于5%。  相似文献   
28.
We have numerically simulated the induced electric fields and the plasmonic interactions of a metallic nanotube near a thin metallic film. Our study shows that the energies and intensities of the plasmon resonances depend strongly on the aspect ratio (the ratio of the inner to outer radius) of the nanotube as well as the separation between the center of the nanotube and the upper surface of the metallic film and the thickness of the film. The enhancement of the induced electric field of this system reaches ...  相似文献   
29.
Based on the analysis theory of random energy of train derailment, an analysis theory of random energy of train derailment in wind is suggested. Two methods are proposed -the time domain method and the frequency domain method of analysis theory of random energy of train derailment in wind. The curves of σ pw -v under various wind speeds are obtained through the computation. The original curve of σ p -v is expanded, which turns the analysis theory of random energy of train derailment into the all-weather theory. Train derailment condition has been established under wind action. The first and second criterions of train derailment have been proposed in light of wind action. The analysis of train derailment cases at home or abroad is made, in- cluding the first analysis of Xinjiang train derailment case encountered 13-level of gale, which explained the inevitability of train derailment. The analysis theory of random energy of train derailment in wind shows its validity and accuracy. The input energy σ pw of the transverse vibration of train-track(bridge)-wind system is linked to train speed. With the establishment of the analysis theory of random energy of train derailment in wind, It is likely to initiate an all-weather speed limit map for a train or any high-speed train.  相似文献   
30.
<正>Diffraction efficiency of volume Bragg grating,whose period is in the same order as the incident wavelength, is related to the polarization direction of the incident linear polarized beam.When two linearly polarized recording beams with the same polarization direction are used for recording volume Bragg gratings in a photopolymer with diffusion amplification,the azimuth of polarization of the reconstruction beam influences the diffraction efficiency of the grating.When the probe beam is linearly polarized and oriented orthogonally to the grating vectors,the±1-order diffraction beams are also linearly polarized with polarization direction parallel to that of the probe beam.According to the results,a two-dimensional nonspatial optical filter consisting of the volume Bragg gratings would achieve significantly higher efficiency.  相似文献   
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