球形汞膜电极电位溶出分析法研究

本文推导出球形汞膜电极电位溶出分析法的过渡时间方程式和E-t曲线方程。实验结果与理论基本相符。球形汞膜电极用于电位溶出分析法,有良好的重现性和经久耐用性。     

独立α粒子模型下的α-~(12)C弹性散射

本文以拟合实验的a—a散射振幅f_a为元振幅,用核的独立a粒子模型波函数,在Glapber理论框架下计算了1.37Gev的a粒子在(12)~C上的弹性散射微分截面。结果与实验较好地符合。     

平台印机转动惯量与制动力矩的计算与测试

介绍对某平台印刷机等效转动惯量和制动力矩的理论计算和测试试验的方法和结果.内容包括运动分析,等效到制动轴的整机等效转动惯量计算,在各种预定时间内制动停止所需的制动力矩计算以及实际测试试验.理论计算与测试所得结果相当吻合.     

齿轮传动试验台微机测量系统

齿轮传动试验台微机测量系统是一种新型的综合测试系统，它克服了齿轮传动试验台传统测量装置的缺陷，实现了对转速、转矩、效率及温升等参数的自动检测及数据处理。     

一种广义二阶导数和二阶次微分

给出了Banach空间X上的实值函数f的一种广义二阶方向导数f~(00)(x;υ;ω)的定义,f~(00)(X;·;·)是X×X上的双正齐次凸泛函.在f~(00)(x;·;·)取有限值时给出了二阶次微分(?)f(x)的定义,当f~(00)(x;·;·)有界时,(?)f(x)是一个非空的有界闭凸集。当X=R~n时,(?)f(x)与Urruty的广义Hessian矩阵一致。     

Effect of temperature on batch elastase production by Bacillus sp. EL31410

The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation, different cultivation temperatures, ranging from 39℃ to 28℃, were evaluated in shake flask. The result indicated that 37℃ was best for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated at 30℃. This result was verified by batch fermentation in 5-L bioreactor under 37 ℃ and 30 ℃ temperature, respectively. The specific cell growth rate at 37 ~C was higher than that at 30 ℃ during earlier stage of cultivation. The maximum value [5.5 U/(h-g DCW)] of elastase formation rate occurred at 24 h at 30℃ compared to 4.6 U/(h-g DCW) at 30 h at 37℃. Based on these results, two-stage temperature shift strategy and oscillatory temperature cultivation mode were evaluated in the next study. When compared to single temperature of 37 ℃ or 30℃, both two-stage temperature shift strategy and oscillatory temperature strategy improved biomass but did not yield the same result as expected for elastase production. The maximum biomass (both 8.6 g/L) was achieved at 30 h at 37℃, but at 42 h using two-stage temperature cultivation strategy. The highest elastase production (652 U/ml) was observed at 30℃ in batch process. It was concluded that cultivation at constant temperature of 30℃ was appropriate for elastase production by Bacillus sp. EL31410.     

Giant magneto-impedance and low-frequency magneto-resistance effect in NiFeB coated composite wires

Composite wires of 100 μm insulated CuBewire plated with a layer of NiFeB were produced by elec-troless-deposition, and their magnetic properties were stud-led. The results showed that a good magneto-impedance (MI)effect can be obtained at relatively low frequency. The largestMI ratio (△Z/Z)max obtained is 250% at 500 kHz. Mag-neto-resistance effect was also observed at low frequency,with the (△R/R)max observed to be -8.5% at 540 Hz and 38.7% at 10 kHz. Results are discussed, and the equivalent resistance and inductance as the result of the NiFeB layer are taken into account.