封口工艺对LR20电池安全性能的影响

对LR20电池的封口工艺进行研究。与对轮轴向旋压卷边工艺制备的电池相比,采用盔口套压工艺制备的LR20电池,集流体爆破压力提高6.7%,70℃高温漏液率降低4%,卷边压力提高5.9%,短路截止爆炸率降低3%,具有更好的安全性能。     

精养鱼塘鱼虾蟹生态养殖高产模式探讨

鱼虾蟹混养可充分利用池塘的水体空间和饵料生物，提高池塘养殖的经济效益，其主要特点是：不需专设防逃墙，通过强化管理来防止河蟹逃逸，在不影响鱼产量的前提下，增加虾蟹的产量，提高水体产出率。我市在该养殖模式方面进行了多年的探索，取得了令人满意的养殖效果。2002年，实行鱼虾蟹混养技术的152亩精养鱼塘，平均亩产鱼550公斤，亩产虾10公斤，亩产河蟹22公斤。现将关键技术报告如下：     

WC@TiO2核壳结构纳米复合材料制备与电催特征

Monotungsten carbide and titania nanocomposite with core-shell(WC@TiO2)structure was prepared by a new approach of spray drying and reduction-carbonization reaction,with titania nanopowder and ammonium metatungstate as precursors,methane as carbon source,and hydrogen as reduction gas.The sample was characterized by X-ray diffraction,scanning electron microscope,high resolution transmission electron microscope and X-ray energy dispersion spectroscopy.The results show that its crystal phase is composed of brookite,tungsten and monotungsten carbide.The morphology of the sample particle is irregular sphere-like,with a diameter smaller than 100 nm.Its chemical components are titanium,tungsten,carbon and oxygen.Monotungsten carbide nanoparticles lie on the surface of titania core and form an incomplete shell around titania core in the nanocomposite.The measurement with a microelectrode system of three electrodes shows that the sample is electrocatalytic active to nitrophenol in basic solution at room temperature.Its peak potential is at0.988 V(vs saturated calomel electrode (SCE)),which is more negative than the peak potential,0.817 V(vs SCE),of mesoporous monotungsten carbide, and its peak current is 8.809μA,which is higher than the peak current,4.058μA,of mesoporous monotungsten carbide.The hydrogen generation potential of the sample is at1.199 V(vs SCE),which is more negative than that of pure nanosized monotungsten carbide at1.100 V(vs SCE).These results show that the presence of titania in the sample can lower the peak potential of nitrophenol electrocatalysis and its hydrogen generation potential,and increase its peak current of nitrophenol electrocatalysis in basic solution at room temperature.This indicates a synergistic effect of titania and monotungsten carbide in electrocatalysis.