Effect of a constant magnetic field on water quality and rearing of European sheatfish Silurus glanis L. larvae

The influence of a constant magnetic field with an intensity ranging from 0.4 to 0.6 T (Tesla) was determined on physicochemical parameters of water and on rearing of larvae of the European sheatfish Silurus glanis L. larvae. In the experiment, feeding brood of European sheatfish was reared in two groups. One was kept in tanks supplied with magnetically treated water. The second group was kept in tanks supplied with water without treatment with a magnetic field (control). The fish tanks were supplied with circulating river water. Rearing was conducted for 15 days at an initial stocking density for both groups of 8 fish per litre. The mean fish mass obtained was 0.46 g, and in the control group – 0.78 g (P<0.05). Stocking mortality was 19.1% in the tanks with a constant magnetic field, and 13.5% in the control group. No changes were observed in water phosphate, ammonium, organic compounds or chloride concentrations.     

Frequency tracking method and simulation for coriolismass flowmter based on a new adaptive notch filter

In order to improve the long-playing frequency tracking ability in the signal processing for coriolis mass flowmeter (CMF) , a new IIR adaptive notch filter (ANF) is developed via steiglitz-mcBride method (SMM) and applied to filter the sensor output signal whose frequency, amplitude and phase are time-varying following the random walk model. The proposed method can detect the signal frequency fleetly and track the frequency variations continuously. The tracking performances of the proposed method and the adaptive lattice notch filter (LANF) method are investigated with computer simulations. Simulations demonstrate the superiority of the proposed method and show it has advantages of fast convergence rate, insensitivity to initial phase variations, and higher long-playing tracking stability and accuracy than LANF method.     

CMF对淀粉酶及过氧化氢酶的激活效应

从酶学角度研究了恒定磁场(CMF)对小麦、水稻的淀粉酶及过氧化氢酶的激活效应。通过CMF对离体淀粉酶等的作用实验发现:CMF对上述酶有明显的激活效应。用CMF处理小麦、水稻种子,进行发芽试验并测定芽期上述酶的活性及某些生理指标的变化,发现它们与离体条件下的酶活性变化规律一致。从而揭示了一个重要机理:磁场生物效应的根源之一是磁场对上述酶的激活效应。