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Calculation of AC Losses of CICC for Superconducting Outsert Coils in a Hybrid Magnet

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Plasma Science and Technology 2010年第5期12卷 636-640页

作者：何鹏陈灼民陈文革谭运飞潘引年王福堂匡光力 high magnetic Field laboratory Chinese Academy of Sciences

This paper is devoted to predict AC loss of cable in conduit conductor （CICC） which is of importance in the design of conductors. The consideration for the conductor＇s design and main parameters for the magnets are introduced. In order to attain a good accuracy in the calculation of AC losses, the field distribution within superconducting outsert should be considered. Calculation of the AC losses, including hysteresis losses and coupling losses, is conducted. An emphasis is put on the hysteresis loss during the ramp up of the current to the operational current （15.3 kA） and the coupling loss of the conductor in a power-down condition for insert. The results are obtained to be 74.9 kJ and 950 J for 40 T hybrid magnets, respectively. Based on the calculation, a brief analysis of losses effect on the conductor design and the operation of magnet is given for the purpose that the capacity of the cryogenertor can be evaluated and the stability regime can be improved in our future work on the hybrid magnets.

关键词： AC losses coupling losses hysteresis superconducting outsert coils

Autophagy in mitotic animal cells

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Science Bulletin 2016年第2期61卷 105-107页

作者： Zhiyuan Li Xin Zhang high magnetic Field laboratory Chinese Academy of Sciences

Mitosis is a highly dynamic cellular event that involves high energy consumption and active membrane *** is a process that cells digest their cellular contents to provide energy and nutrients to maintain *** now,whether autophagy persists during mitosis is still *** most dividing animal cells,the whole cell cycle can be divided into about 20 h of interphase and 1–2 h

关键词：有丝分裂过程动物细胞自噬体内平衡营养物质高耗能 ing 高活性

Dy_(2-x)Y_xTi_2O_7: phonon vibration and magnetization with dilution

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Rare Metals 2015年第2期34卷 81-88页

作者： Hui Liu You-Ming Zou Shi-Le Zhang Ran-Ran Zhang Chang-Jin Zhang Yu-Heng Zhang high magnetic Field laboratory Chinese Academy of Sciences and University of Science and Technology of China

In this paper, the dilution effects of non-magnetic Y ions on spin-ice compound Dy_2Ti_2O_7 by infrared and Raman spectra and magnetization measurements were investigated. An anomalous phonon softening with temperature decreasing is found in both the parent and diluted compounds, and Y doping can relax the softening of phonons except that of the IR mode near 233 cm^-1, indicating a strong phonon–phonon coupling in the spin-ice *** magnetization measurements reveal that the nonmagnetic impurities do not severely influence the spin-ice rules in the ground state when the level of dilution is not very high. However, a large amount of dilution enhance the disorder and break the spin-ice state because the collective spin-flip clusters are no longer available.

关键词： Dilution effect Spin ice Pyrochlore Frustration

Study on a highly Stabilized Power Supply for Hybrid-Magnet Superconducting Outsert

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Plasma Science and Technology 2014年第9期16卷 890-896页

作者：吴景林龙佼佼刘小宁 University of Science and Technology of China high magnetic Field laboratory Chinese Academy of Sciences

The superconducting outsert of the 40 T hybrid-magnet in high magnetic Field laboratory （HMFL） of Chinese Academy of Sciences （CAS） requires a highly stabilized power supply. In this paper, two kinds of power supply design are briefly presented and both advantages and disadvantages are analyzed. In order to overcome the drawbacks of switching power supply, a series regulated active filter is adopted and a new design is proposed which ensures cooperative relationship between the feedback control loops of the switching converter and the series regulated active filter. Besides, unlike the traditional switching power supply, which can generate positive voltage only, this new design can also generate negative voltage which is needed in the quench protection for the superconducting magnet. In order to demonstrate the effectiveness of the methodology, a low-power prototype has been accomplished. The simulation and experiment results show that the power supply achieves high precision under the combined action of two feedback control loops. The peak-to-peak amplitude of the output ripple voltage of the prototype is 0.063%, while the peak-to-peak amplitude of the output ripple current is 120 ppm.

关键词： superconducting magnet switching power supply series regulating feedbackcontrol quench protection

1 T moderate intensity static magnetic field affects Akt/mTOR pathway and increases the antitumor efficacy of m TOR inhibitors in CNE-2Z cells

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Science Bulletin 2015年第24期60卷 2120-2128页

作者： Lei Zhang Xingxing Yang Juanjuan Liu Yan Luo Zhiyuan Li Xinmiao Ji Wenchao Wang Xin Zhang high magnetic Field laboratory Chinese Academy of Sciences University of Science and Technology of China

Static magnetic field （SMF） has been known to affect cell proliferation in a cell-type-dependent manner, while the mechanism still remains unclear. We found that 1 T moderate intensity SMF inhibits cell proliferation of nasopharyngeal carcinoma CNE-2Z cells and the Akt/ mTOR signaling pathway, which is upregulated in many cancers, roTOR inhibitors are potential chemodrugs, but their clinical effects are limited by the feedback reactiva- tion of other signaling components such as EGFR and Akt. We showed that 1 T SMF increases the antitumor efficacy of mTOR inhibitor Torin 2. In addition, 1 T SMF increases the inhibition efficiency on roTOR substrates phosphorylation and represses the mTOR inhibitor-induced feedback reactivation of EGFR and Akt. Our study not only demonstrates that mTOR/Akt pathway is one of the molecular targets of SMFs in cells, but also reveals the clinical potentials of combinations of roTOR inhibitors and SMFs in cancer treatment.

关键词： Static magnetic field - Cell proliferationmTOR mTOR inhibitor - Feedback reactivation

Microstructural Evolution and Performance of In-situ Ag-Ni Composite after Solidification under Electromagnetic Stirring and Deformation

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Journal of Iron and Steel Research International 2016年第7期23卷 638-646页

作者： Lin ZHANG Ke HAN Tian-nan MAN En-gang WANG Xiao-wei ZUO Key laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern University National high magnetic Field laboratory Florida State University

The effect of electromagnetic stirring（EMS）on microstructure and performance of Ag-8 mass%Ni composite was investigated under both solidified and deformed *** EMS,the Ag matrix formed short,thick dendrites in the ingot;whereas with EMS,dendrites were long and *** phase mainly formed particles or ribbons,distributed along boundaries between dendrite *** drawing of the solidified Ag-Ni ingots,both with and without EMS,produced high strength in-situ metal-matrix composite（MMC）consisting of Ag matrix reinforced by Ni *** improved the ductility of the composite,consequently enhancing its drawability and *** also increased the electrical conductivity in both solidified ingots and deformed in-situ composite *** both cases,hardness and tensile strength remained high.A model based on a combination of the modified linear rule of mixtures and the Hall-Petch relationship was used to rationalize the tensile strength and hardness with respect to its fabrication parameters and the microstructure of Ag-Ni in-situ composite.

关键词： Ag-Ni electromagnetic stirring solidification in-situ metal matrix composite

Roles of Electron Hopping on Orbital Ordering for Vanadium Spinels

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Communications in Theoretical Physics 2012年第9期58卷 441-444页

作者：黄元杰张裕恒 high magnetic Field laboratory Chinese Academy of Sciences and University of Science and Technology of China

We investigate the orbitM ordering quantitatively for the spinel systems RV204 （R=Mg, Zn, Cd） in the viewpoint of single-ion physics through the method of diagonalization. Through the quantitative calculation, it is found that the spin-orbit （SO）coupling and the Jahn-Teller （JT） effect enable the orbital ordering under the conditions of negligible electron hopping among different V3＋ sites. For the systems RV204, the electron hopping is implied to be observable from the energy gap in conductivity, so the orbital ordering of RV2 04 cannot be induced by the SO coupling and JT effect at definite temperature, which is on contrary to the conclusions in [Phys. Rev. Lett. 93 （2004） 157206].

关键词： orbital ordering Jahn-Teller effect orbital-spin coupling

Anomalous low-temperature heat capacity in antiperovskite compounds

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Chinese Physics B 2017年第2期26卷 370-374页

作者： Xin-Ge Guo[l,2] Jian-Chao Lin Peng Tong Shuai Lin Cheng Yang Wen-Jian Lu Wen-Hai Song Yu-Ping Sun Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China University of Science and Technology of China Hefei 230026 China high magnetic fiem laboratory Chinese Academy of Sciences Hefei 230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

The low-temperature heat capacities are studied for antiperovskite compounds AX M_3（A = Al, Ga, Cu, Ag, Sn, X = C,N, M = Mn, Fe, Co）. A large peak in（C- γ T）/T^3 versus T is observed for each of a total of 18 compounds investigated,indicating an existence of low-energy phonon mode unexpected by Debye T^3 law. Such a peak is insensitive to the external magnetic field up to 80 k Oe（1 Oe = 79.5775 A·m-1）. For compounds with smaller lattice constant, the peak shifts towards higher temperatures with a reduction of peak height. This abnormal peak in（C- γ T）/T^3 versus T of antiperovskite compound may result from the strongly dispersive acoustic branch due to the heavier A atoms and the optical-like mode from the dynamic rotation of X M_6 octahedron. Such a low-energy phonon mode may not contribute negatively to the normal thermal expansion in AX M_3 compounds, while it is usually concomitant with negative thermal expansion in open-structure material（e.g., ZrW_2O_8, Sc F_3）.

关键词： low-temperature heat capacity low-energy phonon modes antiperovskite compound negative thermal expansion

Mn-based antiperovskite functional materials: Review of research

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Chinese Physics B 2013年第6期22卷 19-31页

作者：童鹏王铂森孙玉平 Key laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of Sciences high magnetic Field laboratory Chinese Academy of Sciences

Our recent research on the Mn-based antiperovskite functional materials AXMn3 （A： metal or semiconducting elements; X： C or N） is outlined. Antiperovskite carbides （e.g., AlCMn3） show large magnetocaloric effect comparable to those of typical magnetic refrigerant materials. Enhanced giant magnetoresistance up to 70% at 50 kOe （1 Oe=79.5775 A.m-1） over a wide temperature span was obtained in Ga1-xZnxCMn3 and GaCMn3 xNix. In Cu0.3Sn0.5NMn3.2, negative thermal expansion （NTE） was achieved in a wide temperature region covering room temperature （α = -6.8 ppm/K, 150 K-40 K）. Neutron pair distribution function analysis suggests the Cu/Sn-Mn bond fluctuation is the driving force for the NTE in Cu1- xSnxNMn3. In CuN1- xCxMn3 and CuNMn3 yCoy, the temperature coefficient of resistivity （TCR） decreases monotonically from positive to negative as Co or C content increases. TCR is extremely low when the composition approaches the critical points. For example, TCR is - 1.29 ppm/K between 240 K and 320 K in CuN0.95C0 05Mn3, which is one twentieth of that in the typical low-TCR materials （- 25 ppm/K）. By studying the critical scaling behavior and X deficiency effect, some clues of localized-electron magnetism have been found against the background of electronic itinerant magnetism.

关键词： antiperovskite magnetocaloric effect giant magnetoresistance negative thermal expansion