Convection effect on an arc plasma evolution process in a two parallel contact system

A low voltage circuit breaker(LVCB)is an important piece of protection equipment which will switch off the fault current in a power system.The moving contact of a low voltage circuit breaker with a higher rated current consists of two parallel contacts.Therefore,the convection effect on the air arc evolution process in a two parallel contact system is analyzed.A threedimensional(3 D)magneto–hydro–dynamic(MHD)model of arc simulation is built.In this model,the anode consists of two parallel contacts and a bonding conductor.A nonlinear voltage–current density characteristic is employed to represent the near-anode and near-cathode voltage.The current density,arc voltage and currents through every contact are obtained.The influence of convection and conduction on the arc evolution process are quantitatively calculated.The displacements of the arc roots are obtained and the asymmetry of the arc root motion is analyzed.The arc evolution process of a two parallel contact system is preliminarily revealed.

Evaluation method for electromagnetic interference complexity of high voltage switch based on feature extraction and GCC-GRU network

When some new-type sensors are subjected electromagnetic interference(EMI),the traditional standard can no longer serve as the guidance for their EMI protection.Therefore,it is necessary to evaluate the complexity of the new sensing equipment's suffering from electromagnetic interference.A hybrid method of feature extraction and complexity evaluation of Electromagnetic Interference signals based on generalised correntropy criterion(GCC)is proposed.First,a variational mode decomposition al-gorithm for adaptive extraction of decomposed signals is constructed using GCC,and Generalised S-transform is used for processing and reorganisation.Then,according to the time-frequency space model,a new quantitative evaluation criterion interference factor is proposed,which overcomes the shortcomings of the traditional qualitative classification and the inability to solve the cross classification of indicators.Then,the Gated Recurrent Unit is introduced,and the GCC-GRU evaluation model with GCC as the loss function is derived.The authors conduct EMI tests and measured signal eval-uation with Medium Voltage and High Voltage switches,and the results show that the method proposed is correct and effective.

A Novel Approach for Identifying the Heme-Binding Proteins from Mouse Tissues

Heme is a key cofactor in aerobic life, both in eukaryotes and prokaryotes. Because of the high reactivity of ferrous protoporphyrin IX, the reactions of heme in cells are often carried out through heme-protein complexes. Traditionally studies of heme-binding proteins have been approached on a case by case basis, thus there is a limited global view of the distribution of heme-binding proteins in different cells or tissues. The procedure described here is aimed at profiling heme-binding proteins in mouse tissues sequentially by 1) purification of heme-binding proteins by heme-agarose, an affinity chromatographic resin; 2) isolation of heme-binding proteins by SDS-PAGE or two-dimensional electrophoresis; 3) identification of heme-binding proteins by mass spectrometry. In five mouse tissues, over 600 protein spots were visualized on 2DE gel stained by Commassie blue and 154 proteins were identified by MALDI-TOF, in which most proteins belong to heme related. This methodology makes it possible to globally characterize the heme-binding proteins in a biological system.