旱草枯防除辣椒地杂草试验

辣椒是云南省文山州的主要经济作物之一 ,常年种植 2万公顷以上。长期以来 ,辣椒地杂草主要是靠人工薅除 ,只有很少一部分用威霸ＥＷ进行化除。为了进一步找到适合我州辣椒生产的高效、低成本化除药剂 ,我们在文山县红甸乡进行了 5 %旱草枯ＥＣ防除辣椒地杂草试验。试验结果表明 ,5 %旱草枯ＥＣ对以禾本科为主的辣椒地杂草有显著的防除效果 ,对辣椒安全 ,可以在大面积生产中推广应用。1　材料及方法1 1　试验地概况试验地为红壤 ,前作小麦 ,未施用除草剂。主要草种有马唐、狗尾草、鬼针 ,其中禾本科杂草占90 %。1 2　辣椒品种本地邱北辣。1 …     

Experimental study of density gradient-driven micro-instabilities and the confinement degradation during H-mode in EAST

A broadband(BB) mode is observed by collective Thomson scattering diagnostics in repeatable shots of EAST and analyzed for the first time. This BB mode usually grows during L–H transitions,featuring a BB quasi-coherent mode with increasing frequency. During H-mode operations, it is characterized by steady-state BB in the high-frequency range( f ～ 200–2000 k Hz), at the electron scale(k_θρ_s= 1–2), mainly driven by the density gradient, and is sensitive to the value of ηein th...     

Spatial localization of ECE measurement in EAST LHW-heated plasmas

In this work, electron cyclotron emission (ECE) is simulated by using the code SPECE to study the spatial localization of ECE measurement in EAST plasmas heated by lower hybrid wave (LHW). The results indicate that generally there are two emission layers for an individual frequency in plasmas with non-thermal electrons, and they are separately attributed to the thermal electrons and non-thermal electrons. The emission layer due to the thermal electrons is nearly identical to that for the case with Maxwellian distribution. The emission layer due to non-thermal electrons is well localized in the location of the non-thermal electrons. Even though the non-thermal emission layer is broader, the emission intensity is smaller than that from the thermal emission layer for the cases studied in this work. Localized electron temperature fluctuations can still be distinguished by ECE measurement as long as it does not coexist with the non-thermal electrons. Sawtooth inversion radii and tearing mode island location determined respectively by the ECE measurement and the soft x-ray measurement for a LHW-heated plasma show a good agreement, and this indicates that the ECE measurement in the plasma core region is not seriously polluted.