物理防治在控制豇豆虫害中的作用

本文通过田间调查豇豆生产期与结荚期主要虫害(斑潜蝇、豆荚螟、豆蚜、蝽象)的发生情况,发现不同的物理措施在控制病虫害方面的作用存在差异;同时,结合对天敌的影响、产量、质量、经济效益综合评价物理防治在控制豇豆病虫害的作用.结果表明,防虫网对斑潜蝇控制效果达59.19%,对豆荚螟、豆蚜、蝽象高达100%;黄板区与灯防区在降低成虫虫口基数上起到良好的效果,平均每天黄板诱虫58.2头/块,杀虫灯在虫害发生期间诱虫重量达15.4g/d,以每克含虫5～20头计,达76～308头/d,最高峰5月中旬时能达625～2500头/d,有效减少田间害虫虫口基数.从综合经济效益的角度相比,防虫网处理区(4177.2元)＞黄板区(35392.5元)＞灯防区(32832.0元)＞常规施药区(25758.0元).     

Performance of thermoelectric generator with graphene nanofluid cooling

Improvement of the heat transfer of the cold side is one of the approaches to enhance the performance of TEG systems.As a new type of heat transfer media, nanofluids can enhance the heat transfer performance of working liquid significantly.Based on a three-dimensional and steady-state numerical model,the heat transfer and thermoelectric conversion properties of TEG systems were studied. Graphene anoplatelet aqueous nanofluids were used as the coolants for the cold side of the TEG system to improve the heat transfer capacity of the cold side. The results showed that the heat absorbed by the hot side, voltage, output power, and conversion efficiency of the TEG system were increased greatly by the nanofluid coolants.The output power and the conversion efficiency using 0.1-wt% graphene nanoplatelet aqueous nanofluid as the coolant are enhanced by 26.39% and 14.74%, respectively.