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SOHO/SUMER太阳紫外光谱仪的N Ⅳ谱线观测到太阳南极区冕洞内存在许多小尺度结构,其空间尺度约1~几角秒,寿命尺度约1~几min。小尺度结构沿狭缝方向呈条状,视向多普勒速度可至几十km·s-1。在有的南极区冕洞区域内,小尺度结构的视向多普勒速度呈红、蓝移准周期性交错分布,持续时间长达100 min。部分小尺度结构在同一观测窗口的高温Ne ⅤⅢ谱线还可清晰显现。有的小尺度结构在Ne ⅤⅢ速度演化图的时间和位置与N Ⅳ 谱线速度图基本一致,但它们在Ne ⅤⅢ速度演化图中更延展和弥散。N Ⅳ紫外光谱显示部分小尺度结构谱线呈现非高斯形状,谱线两翼速度可达150 km·s-1,与太阳过渡区爆发事件的光谱特征相似。太阳过渡区爆发事件常出现在宁静区,SOHO/SUMER太阳紫外光谱仪的N Ⅳ谱线显示在南极区冕洞也可产生爆发事件,且具有较强的动力学特征。 相似文献
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Comparisons of ZnO codoped by group IIIA elements (Al, Ga, In) and N: a first-principle study 下载免费PDF全文
The electronic structures and effective masses of the N mono-doped and Al-N,Ga-N,In-N codoped ZnO system have been calculated by a first-principle method,and comparisons among different doping cases are made.According to the results,the impurity states in the codoping cases are more delocalised compared to the N mono-doping case,which means a better conductive behaviour can be obtained by codoping.Besides,compared to the Al-N and Ga-N codoping cases,the hole effective mass of In-N codoped system is much smaller,indicating the p-type conductivity can be more enhanced by In-N codoping. 相似文献
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Adding a U(1) symmetry breaking term V1/2 a(λ1a0+λ*1a8224;0)+V1/2(λ2b0+λ*2b8224;0) to Bogoliubov's truncated Hamiltonian HB for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking. 相似文献
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Comparisons of ZnO codoped by group ⅢA elements (Al,Ga, In) and N: a first-principle study 下载免费PDF全文
The electronic structures and effective masses of the N mono-doped and Al N, Ga-N, In-N codoped ZnO system have been calculated by a first-principle method, and comparisons among different doping cases are made. According to the results, the impurity states in the codoping cases are more delocalised compared to the N mono-doping case, which means a better conductive behaviour can be obtained by codoping. Besides, compared to the Al-N and Ga-N codoping cases, the hole effective mass of In-N codoped system is much smaller, indicating the p-type conductivity can be more enhanced by In N codoping 相似文献
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Using a first-principle method, the electronic structures and the impurity formation energy of ZnO, ZnO (N), ZnO (N+B), and ZnO (2N+B) have been calculated, based on which the feasibility to obtain p-type ZnO & discussed. According to the results, when ZnO is single doped by N, the acceptor level is deep, and the formation energy is negative, so the ideal p-type ZnO can not be obtained by this way. On the contrary, when 2N+B are codoped into ZnO, the acceptor level becomes much lower, and the formation energy is positive, so it is a better way to obtain p-type ZnO. 相似文献
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本文根据理想气体的状态方程及热力学定律,利用高等数学的偏微分方法证明了理想气体的内能完全决定于气体的热力学温度T,而与体积V无关。 相似文献