The variable polarity power source which incorporates a constant current power and a secondary inverter does not need special apparatus for stabilizing arc. The pulse for stabilizing arc is created by the circuit stru...The variable polarity power source which incorporates a constant current power and a secondary inverter does not need special apparatus for stabilizing arc. The pulse for stabilizing arc is created by the circuit structure itself. The paper analyzes the principle of acquiring the pulse, provides the better method to improve the arc stabilization under smaller welding current. Test shows the arc is highly stable , and the process has no high frequency electromagnetic interference, which is suitable for automatic welding case.展开更多
We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous...We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous function defined in with 0 〈 q- infq（x） = q（x） 〈 ∞supq（x） = q＋ 〈 ∞. It is demonstrated that the equation with variable source power has much richer dynamics with interesting phenomena which depends on the interplay of q（x） and the structure of spatial domain Ω, compared with the case of constant source power. For the case that is a bounded domain, the exponent p - 1 plays a crucial role. If q＋ 〉 p - 1, there exist blow-up solutions, while if q＋ p - 1, all the solutions are global. If q-〉 p - 1, there exist global solutions, while for given q- 〈 p - 1 〈 q＋, there exist some function q（x） and such that all nontrivial solutions will blow up, which is called the Fujita phenomenon. For the case Ω = RN the Fujita phenomenon occurs if 1 q＋ q＋ ≤p--1＋p/N, while if q_ 〉 p -- 1 ＋p/N there exist global solutions.展开更多
基金This research was supported inpart by the Found ation !(No .990 951 1 1 2 )for Research admini stered by HarbinInstituteof Te
文摘The variable polarity power source which incorporates a constant current power and a secondary inverter does not need special apparatus for stabilizing arc. The pulse for stabilizing arc is created by the circuit structure itself. The paper analyzes the principle of acquiring the pulse, provides the better method to improve the arc stabilization under smaller welding current. Test shows the arc is highly stable , and the process has no high frequency electromagnetic interference, which is suitable for automatic welding case.
基金supported by Shanxi Bairen Plan of China and Ng-Jhit-Cheong Foundation
文摘We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous function defined in with 0 〈 q- infq（x） = q（x） 〈 ∞supq（x） = q＋ 〈 ∞. It is demonstrated that the equation with variable source power has much richer dynamics with interesting phenomena which depends on the interplay of q（x） and the structure of spatial domain Ω, compared with the case of constant source power. For the case that is a bounded domain, the exponent p - 1 plays a crucial role. If q＋ 〉 p - 1, there exist blow-up solutions, while if q＋ p - 1, all the solutions are global. If q-〉 p - 1, there exist global solutions, while for given q- 〈 p - 1 〈 q＋, there exist some function q（x） and such that all nontrivial solutions will blow up, which is called the Fujita phenomenon. For the case Ω = RN the Fujita phenomenon occurs if 1 q＋ q＋ ≤p--1＋p/N, while if q_ 〉 p -- 1 ＋p/N there exist global solutions.
