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Bai Z.,Northeastern University China | Ma C.,Northeastern University China | Chen C.,Northeastern University China | Pang Y.,Baosheng Science and Technology Innovation Co.
IEEE Transactions on Applied Superconductivity | Year: 2017

This paper presents further research on the pulse-type magnetic flux pump (MFP). The pulse-type MFP is used to excite a Bi-2223 double-pancake superconducting coil cooled by a cryocooler. The inductance of the coil is 76 μH. The cryogenic structure of the MFP is optimized by adding a cold frame outside. The MFP is powered by a dc voltage source. The excitation effects on the Bi-2223 coil are investigated by changing the input voltage. The pumping current curves have been obtained with various input voltage from 2.0 to 5.5 V. The fitting calculations show that the saturated current in Bi-2223 high-temperature superconductor (HTS) coil is 200 A when the input voltage is 5 V. The joint resistance is also numerically analyzed, and it is 0.18 μΩ. By measuring the current ripple of the Bi-2223 HTS coil, it is found that the excitation current fluctuation is ±4 A when the input voltage is 5 V. Consequently, it is expected that the pulse-type MFP could compensate the decaying current caused by the low n-index and joint resistance and enable the HTS magnet operating in persistent current mode. Further optimization on the structure and pumping process is still needed to improve the excitation properties of the pulse-type MFP. © 2002-2011 IEEE.


Wu Y.,CAS Hefei Institutes of Physical Science | Qin J.-G.,CAS Hefei Institutes of Physical Science | Liu B.,CAS Hefei Institutes of Physical Science | Liu F.,CAS Hefei Institutes of Physical Science | And 13 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2016

The ITER magnet system is made up of four main subsystems: the 18 toroidal field (TF) coils, the central solenoid, the six poloidal field (PF) coils, and the correction coils (CCs). The feeder system, with its main busbar (MB) and CC busbar (CB), represents one of the main magnet components as well. All coils and busbars with different dimensions used cable-in-conduit conductors. China has signed three conductor packages, which are the so-called procurement arrangements, between ITER and the Chinese Domestic Agency (CN DA): a TF conductor package, a PF conductor package, and a CC and feeder conductor package. They include 7.5% of the TF conductors (11); all the PF2 (12), PF3 (16), PF4 (16), and PF5 (16) conductors; all the CC (18) conductors; and the MB (3) and CB (2) conductors for the feeders. Complex technologies have been developed by ASIPP for the serial production of all ITER conductors, in terms of cabling parameter design, welding, and elaboration of cable insertion, compaction, and winding processes. China has finished all qualification phases and is well into the main series production. All conductor samples required for quality control have successfully passed the SULTAN tests with good performance. The status of the production of ITER conductors in China is described in this paper. © 2002-2011 IEEE.


Wang F.,Beijing Institute of TechnologyBeijing | Hao J.-W.,Beijing Institute of TechnologyBeijing | Hao J.-W.,Baosheng Science and Technology Innovation Co. | Li Z.-S.,Baosheng Science and Technology Innovation Co. | Zou H.-F.,Baosheng Science and Technology Innovation Co.
Acta Polymerica Sinica | Year: 2015

Bamboo-based porous carbon materials (PCM) were preparated by chemical activation method with KOH as porogen. Then the synergistic flame retardant effect and mechanism of PCM/ammonium polyphosphate (APP) in epoxy resin (EP) were investigated. The surface performance, microstructure and chemical structure were characterized by physical adsorption (BET method), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) respectively; fire behaviors of the flame-retardant EP were studied by the limit oxygen index (LOI), UL 94 vertical burning test and cone calorimetry. The results showed that the specific surface area, pore volume and pore diameter of PCM (PCM6) were 2063 m2/g, 0. 9 cm3/g and 1. 8 nm respectively, the particle size was 1-5 μm, the active groups such as C-C, C-O -, C = O and COO-were detected on the surface of PCM6; for formulations containing APP (3. 1 wt% ) and PCM (0. 8 wt% ), the LOI value was significantly increased from 24. 6% to 27. 3%, the peak heat release rate decreased by 45. 4%, compared to pure EP, the time to ignition of the flame-retardant EP was prolonged by 10% than EP/3. 1 APP. Moreover, thermo-gravimetric analysis (TGA) and XPS study indicate that PCM6 can improve the thermal stability of the flame-retardant EP, catalyze the thermal degradation of APP to release NH3 and H2O, accelerate the cross-linking and char formation and promote the formation of pyrophosphate during the thermal degradation. The synergistic flame retardant effect and mechanism of PCM and APP in flame-retardant EP were revealed.


Peng H.,Beijing Institute of Technology | Hao J.,Beijing Institute of Technology | Hao J.,Baosheng Science and Technology Innovation Co. | Li Z.,Baosheng Science and Technology Innovation Co. | And 2 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2014

On the basis of research on compounding aluminium hydroxide(ATH) and magnesium hydroxide (MH) with LLDPE, the synergistic flame-retardant and smoking suppression effect of microencapsulated red phosphorus(MRP) and its compounding with zinc borate(ZB) in LLDPE/ATH/MH were studied. The research of combustion performance indicates that MRP has good synergistic flame retardant effect in LLDPE/ATH/MH and the compounding of MRP and ZB can act better. The limiting oxygen index (LOI) of the LLDPE/ATH/MH/MRP/ZB system can rise up to 38.1% and the maximum smoke density (Dm) can decrease to 53 when the addition of flame retardants is 93 phr. The thermogravimetic analysis (TGA) and X-ray photoelectron spectroscopy (XPS) results show that the cross linking and char formation dominate in the synergism flame retardant and suppressing smoke effect in condensed phase.


Peng H.,Beijing Institute of Technology | Zhou Y.,Beijing Institute of Technology | Hao J.,Beijing Institute of Technology | Hao J.,Baosheng Science and Technology Innovation Co. | And 2 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2015

With the excellent catalytic synergistic flame retardancy of metal oxide (MO) and its effect of improving the thermal ageing property as well as the porous and large specific surface area characteristic of bamboo based active carbon (AC), a series of metal oxide (Fe2O3, CuO, ZnO) supported on active carbon (AC-MO) synergist was prepared by solvent evaporation method. The vulcanization, combustion, thermostability, and thermal ageing properties for synergistic intumescent flame retardant ethylene vinyl-acetate copolymer rubber (EVM) with AC-MO and ammonium polyphosphate/dipentaerythritol was studied. The results showed that AC-MO was the target product and MO dispersed well when supported on AC. AC and AC-MO had a uniform dispersion in the flame retardant EVM. The introduction of AC-MO improved the maximum torque, flame retardancy, and char residue, especially for AC-Fe2O3. A Fe2O3 supported on AC improved its catalytic charring effect, which improved the integrity and compactness of char residue of flame retardant EVM. As a result, the flame retardancy was improved. After thermal ageing test, the tensile strength of EVM/IFR/AC-MO increased while the elongation at break decreased. © 2015, Higher Education Press. All right reserved.


Peng H.,Beijing Institute of Technology | Zhou Y.,Beijing Institute of Technology | Hao J.,Beijing Institute of Technology | Hao J.,Baosheng Science and Technology Innovation Co. | And 2 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2016

The effect of bamboo based active carbon (AC) on vulcanization, combustion and mechanical properties of intumescent flame retardant ethylene vinyl-acetate rubber (EVM) was studied. The study of vulcanization property indicates that a network is formed due to the percolation effect of AC in EVM. With the increase of AC content, the maximum torque and viscosity of flame retardant EVM increase. The rheological and swelling measurements show that the percolation effect of AC improves the shear viscosity and crosslink density of flame retardant EVM which is benefit for the improved flame retardancy and mechanical properties. The analysis of microstructure demonstrates the formation of the network of AC from microscopic viewpoint. The results of combustion and mechanical tests prove that there is synergistic effect between AC and intumescent flame retardant (IFR) and the flame retardancy of EVM is improved due to the percolation effect of AC. The optimum flame retardancy is obtained when the mass ratio of IFR and AC is 37:3. The limit oxide index (LOI) achieves 33.6% and 28.7% when the addition of flame retardant is 40% and 25% respectively. Besides, the heat release also decreases significantly. The tensile strength of flame retardant EVM improves with the increasing of AC, while the elongation at break decreases. AC shows its superiority in balancing the vulcanization, flame retardancy, and mechanical properties of flame retardant EVM, which is conductive to improve its comprehensive performance. © 2016, Chengdu University of Science and Technology. All right reserved.

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