In this study, an effective deposition of Ni-P alloy on polyester （PET） was proposed by a chemical plating method with PdCl2 solution and a chelating agent chitosan （CTS）. As a critical step in chemical plating of...In this study, an effective deposition of Ni-P alloy on polyester （PET） was proposed by a chemical plating method with PdCl2 solution and a chelating agent chitosan （CTS）. As a critical step in chemical plating of making electromagnetic shielding fabric, the optimized processing of textile chemical plating is the fabrics padded with 3 % acetic acid （HAc） solution containing 10 g/L CTS and 5.5 mL/L formaldehyde （HCHO） as cross-linking agent for 20 min at room temperature. The highest weight gain and the lowest surface resistance of the treated fabric were achieved by the optimum pretreatment method. The CTS-Pd PET fabrics were characterized by scanning electron microscopy （SEM）, scanning probe microscope （SPM）, and the glancing incident angle X-ray diffraction （XRD） pattern. The results showed that CTS acting as a chelating had effectively fixed Pd （H） ions. A uniform and continuous structure of Ni-P plating layer was obtained using the CTS pretreatment.展开更多
The central solenoid（CS）is one of the key components of the International Thermonuclear Experimental Reactor（ITER）tokamak and which is often considered as the heart of this fusion reactor.This solenoid will be bui...The central solenoid（CS）is one of the key components of the International Thermonuclear Experimental Reactor（ITER）tokamak and which is often considered as the heart of this fusion reactor.This solenoid will be built by using Nb3Sn cablein-conduit conductors（CICC）,capable of generating a 13 T magnetic field.In order to assess the performance of the Nb3Sn CICC in nearly the ITER condition,many short samples have been evaluated at the SULTAN test facility（the background magnetic field is of 10.85 T with the uniform length of 400 mm at 1%homogeneity）in Centre de Recherches en Physique des Plasma（CRPP）.It is found that the samples with pseudo-long twist pitch（including baseline specimens）show a significant degradation in the current-sharing temperature（Tcs）,while the qualification tests of all short twist pitch（STP）samples,which show no degradation versus electromagnetic cycling,even exhibits an increase of Tcs.This behavior was perfectly reproduced in the coil experiments at the central solenoid model coil（CSMC）facility last year.In this paper,the complex structure of the Nb3Sn CICC would be simplified into a wire rope consisting of six petals and a cooling spiral.An analytical formula for the Tcs behavior as a function of the axial strain of the cable is presented.Based on this,the effects of twist pitch,axial and transverse stiffness,thermal mismatch,cycling number,magnetic distribution,etc.,on the axial strain are discussed systematically.The calculated Tcs behavior with cycle number show consistency with the previous experimental results qualitatively and quantitatively.Lastly,we focus on the relationship between Tcs and axial strain of the cable,and we conclude that the Tcs behavior caused by electromagnetic cycles is determined by the cable axial strain.Once the cable is in a compression situation,this compression strain and its accumulation would lead to the Tcs degradation.The experimental observation of the Tcs enhancement in the CS STP samples should be considered as a contribution of the shorter length of the high field zone in SULTAN and CSMC devices,as well as the tight cable structure.展开更多
Electromagnetic(EM) missile sources have so far been limited to the cases where the spatial distribution of current density is either a straight line or a circular disk or a rectangle. It may then be questioned whethe...Electromagnetic(EM) missile sources have so far been limited to the cases where the spatial distribution of current density is either a straight line or a circular disk or a rectangle. It may then be questioned whether an arbitrary linear current distribution or an arbitrary surface current distribution can be used as a launcher of the EM missiles. In this paper the above question is answered, and we have demonstrated that an arbitrary linear or an arbitrary surface current distribution of finite size has the ability to launch an EM missile, i. e. to realize slow decrease of electromagnetic energy on any axis so long as the axis has an intersection point with the source region, and in the neighborhood of this point the spatial distributions of the current are locally flat and perpendicular to the axis.展开更多
文摘In this study, an effective deposition of Ni-P alloy on polyester （PET） was proposed by a chemical plating method with PdCl2 solution and a chelating agent chitosan （CTS）. As a critical step in chemical plating of making electromagnetic shielding fabric, the optimized processing of textile chemical plating is the fabrics padded with 3 % acetic acid （HAc） solution containing 10 g/L CTS and 5.5 mL/L formaldehyde （HCHO） as cross-linking agent for 20 min at room temperature. The highest weight gain and the lowest surface resistance of the treated fabric were achieved by the optimum pretreatment method. The CTS-Pd PET fabrics were characterized by scanning electron microscopy （SEM）, scanning probe microscope （SPM）, and the glancing incident angle X-ray diffraction （XRD） pattern. The results showed that CTS acting as a chelating had effectively fixed Pd （H） ions. A uniform and continuous structure of Ni-P plating layer was obtained using the CTS pretreatment.
基金supported by the National Natural Science Foundation of China(Grant 11622217)the National Key Project of Scientific Instrument and Equipment Development(Grant 11327802)supported by the Fundamental Research Funds for the Central Universities(Grants lzujbky-2017-ot18,lzujbky-2017-k18)
文摘The central solenoid（CS）is one of the key components of the International Thermonuclear Experimental Reactor（ITER）tokamak and which is often considered as the heart of this fusion reactor.This solenoid will be built by using Nb3Sn cablein-conduit conductors（CICC）,capable of generating a 13 T magnetic field.In order to assess the performance of the Nb3Sn CICC in nearly the ITER condition,many short samples have been evaluated at the SULTAN test facility（the background magnetic field is of 10.85 T with the uniform length of 400 mm at 1%homogeneity）in Centre de Recherches en Physique des Plasma（CRPP）.It is found that the samples with pseudo-long twist pitch（including baseline specimens）show a significant degradation in the current-sharing temperature（Tcs）,while the qualification tests of all short twist pitch（STP）samples,which show no degradation versus electromagnetic cycling,even exhibits an increase of Tcs.This behavior was perfectly reproduced in the coil experiments at the central solenoid model coil（CSMC）facility last year.In this paper,the complex structure of the Nb3Sn CICC would be simplified into a wire rope consisting of six petals and a cooling spiral.An analytical formula for the Tcs behavior as a function of the axial strain of the cable is presented.Based on this,the effects of twist pitch,axial and transverse stiffness,thermal mismatch,cycling number,magnetic distribution,etc.,on the axial strain are discussed systematically.The calculated Tcs behavior with cycle number show consistency with the previous experimental results qualitatively and quantitatively.Lastly,we focus on the relationship between Tcs and axial strain of the cable,and we conclude that the Tcs behavior caused by electromagnetic cycles is determined by the cable axial strain.Once the cable is in a compression situation,this compression strain and its accumulation would lead to the Tcs degradation.The experimental observation of the Tcs enhancement in the CS STP samples should be considered as a contribution of the shorter length of the high field zone in SULTAN and CSMC devices,as well as the tight cable structure.
基金Project supported by the National Funds for Postdoctorates.
文摘Electromagnetic(EM) missile sources have so far been limited to the cases where the spatial distribution of current density is either a straight line or a circular disk or a rectangle. It may then be questioned whether an arbitrary linear current distribution or an arbitrary surface current distribution can be used as a launcher of the EM missiles. In this paper the above question is answered, and we have demonstrated that an arbitrary linear or an arbitrary surface current distribution of finite size has the ability to launch an EM missile, i. e. to realize slow decrease of electromagnetic energy on any axis so long as the axis has an intersection point with the source region, and in the neighborhood of this point the spatial distributions of the current are locally flat and perpendicular to the axis.
