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The stress and strain analysis is indispensable for the design and development of high field superconducting magnet. In this paper, a stress analysis with elastic and plastic theory for high magnetic field split superconducting magnet was introduced. By the stress analysis theory, the stress of 13 T split superconducting magnet for neutron scattering was simulated and discussed. Based on the analysis results, the structure of coils was modified by three ways including reduce the maximum magnetic field, applied pre-stress and increased thermal stress. After modified, the peak stress is 165 MPa appeared on the third Nb3Sn coils when the magnet is charged to operating current of 114 A. The peak value of radial stress on superconducting coils is 11.4 MPa appeared on the inner Nb3Sn coils reduced from 21.3 MPa. The stress along axis on the coils is less than 80.7 MPa reduced from 90.6 MPa. The hoop stress on the superconducting coils is 154 MPa which effected on the inner side of the third Nb3Sn coils reduced from 171 MPa. The developing risk of 13 T split superconducting magnet for neutron scattering is reduced significantly.

A supervisory control for neutron scattering superconducting magnet is proposed in this paper, which adopts hierarchical control strategy. In the field layer, programmable logic controller (PLC) based on monitoring control and data acquisition system is used for automatic control of various working conditions. PLC and upper monitoring computer are independent of each other in the equipment control layer, and independent operation is not dependent on the upper computer, which ensures the independence and safety of the process. The running parameters of superconducting magnet can be detected in real-time with the coverage of local area network (LAN), and the significant equipment of neutron scattering superconducting magnet can be controlled by using real-time control method in the mobile environment. In case of abnormal situation, the backfeed control will be used to realize remote alarm and other functions, which ensures the normal running of neutron scattering superconducting magnet safely and reliably.

Indirect immunofluorescence staining was used to detect cytological changes of isolated blastodisks during mitosis of flounder haploid eggs treated with hydrostatic pressure. Changes in microtubule structure and expected cleavage suppression were observed from blastodisk formation to the third cell cycle, with obvious differences between treated and control eggs. In most eggs, microtubules were disassembled and the nucleation capacity of the centrosome was temporarily inhibited after pressure treatment. Within 15-20 min after treatment, the nucleation capacity of the centrosome began to gradually recover, with slow regeneration of microtubules; approximately 25 min after treatment, the nucleation capacity of the centrosome recovered completely, regenerated distinct bipolar spindles, and the first mitosis ensued. During the second cell cycle, approximately 61% of the embryos were at the two-cell stage, with a monopolar spindle in each blastomere; that treatment was effective was based on second cleavage blockage. Approximately 15% of the eggs still remained at the one-cell stage and had a monopolar spindle (treatment was effective, according to the general model of first cleavage blockage). However, treatment was ineffective in approximately 15% of the embryos (bipolar spindle in each blastomeres) and in another 8% (bipolar spindle in one of the two blastomeres and a monopolar spindle in the other; both mechanisms operating in different parts of the embryo). This is the first report elucidating mitotic gynogenetic diploid induction by hydrostatic pressure in marine fishes and provides a cytological basis for developing an efficient method of inducing mitotic gynogenesis in olive flounder. (C) 2007 Elsevier Inc. All rights reserved.

A superconducting magnet for 9.4 Tesla whole-body magnetic resonance imaging is designed and fabricated in Institute of Electrical Engineering, Chinese Academy of Sciences. In this paper, the electromagnetic design methods of the main coils and compensating coils are presented. Sensitivity analysis is performed for all superconducting coils. The design of the superconducting shimming coils is also presented and the design of electromagnetic decoupling of the Z2 coils from the main coils is introduced. Stress and strain analysis with both averaged and detailed models is performed with finite element method. A quench simulation code with anisotropic continuum model and control volume method is developed by us and is verified by experimental study. By means of the quench simulation code, the quench protection system for the 9.4 T magnet is designed for the main coils, the compensating coils and the shimming coils. The magnet cryostat design with zero helium boiling-off technology is also introduced.