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以改进型无限冷硬铸铁为研究对象,采用光学显微镜、扫描电镜(SEM)、X射线衍射仪(XRD)、冲击试验机、硬度机等分析测试手段,研究了RE复合变质剂对改进型无限冷硬铸铁组织和力学性能的影响。实验结果表明,RE复合变质处理改善了改进型无限冷硬铸铁的铸态组织,细化了晶粒,消除了树枝状晶,减少了莱氏体形态的碳化物数量,使连续网状碳化物转变为不连续的网状、孤岛状和鱼骨状碳化物,碳化物的尖角明显钝化;变质无限冷硬铸铁的硬度达到56HRC,冲击韧度达到4.6 J/cm2,比未变质的无限冷硬铸铁分别提高了7.7%和31.4%。 相似文献
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通过分析锤式破碎机锤头的失效形式,提出用高铬铸铁制作锤头,并对高铬铸铁化学成分进行了科学设计,为提高高铬铸铁锤头抗断裂能力,研究了高铬铸铁锤头的复合铸造工艺和热处理工艺。工业试验表明,高铬铸铁复合锤头用于破碎热烧结矿,其使用寿命达到高锰钢的3倍以上。 相似文献
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从原材料使用、化学成分选择、材质金相组织中石墨和碳化物形态的选择、热处理工艺的试验以及铸造工艺等方面,进行改进型高镍铬离心铸铁轧辊的研制。结果表明,其耐磨性和抗事故性兼优、综合性能良好;轧机使用毫米轧制量比普通型高镍铬离心铸铁轧辊的提高10%~20%。 相似文献
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以信息化建设为契机,对梅钢的铸铁库存管理流程再造整合,通过“ERP铁区”平台,集成了多牌号、多库位、多批次、周转快、出库与直装交叉、水运陆运交叉并行的铸铁库存管理技术,理顺了铸铁的物流信息关系,实现了铸铁生产、仓储、发运的集成优化管理,不仅保证了客户的质量需求和供货数量准确,而且提升了梅钢的管理效益。 相似文献
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本文运用动力学理论研究了向铸铁溶液中吹入氮气时氮的溶解过程,建立了相应的数学模型,并通过与实验结果进行拟合计算,确定了氮在铸铁溶液中溶解的主要环节及氮在铸铁溶液中的化学反应速度常数的扩散系数等参数。 相似文献
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以草酸钇铕(Y2(C2O4)3:Eu3+)为前驱体,采用复合熔盐(NaCl+S+Na2CO3)协助焙烧法合成Y2O3:E.u3+红色荧光粉.利用XRD、SEM、光谱分析等测试和分析荧光粉粒径、颗粒形貌以及发光性能.主要考察复合熔盐配比、用量以及焙烧温度和时间对Y2O3:Eu3+荧光粉发光性能的影响.结果表明,NaCl在... 相似文献
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Nitric oxide may regulate cellular respiration by competition with oxygen at mitochondrial cytochrome oxidase. Using an astrocyte-derived cell line, we have compared the mechanism of action of the nitric oxide-generating compound Roussin's black salt with that of sodium nitroprusside on cellular oxygen consumption. Intense light exposure induced the release of large quantities of nitric oxide from both of the donor compounds. However, in room light only Roussin's black salt generated low levels of the radical. Simultaneous measurement of oxygen consumption and of nitric oxide production demonstrated that sodium nitroprusside only had inhibitory actions when exposed to intense light (nitric oxide release), whereas Roussin's black salt had inhibitory actions in room light. Extracellular haemoglobin did not prevent the inhibition of respiration rate induced by Roussin's black salt even though stimulation of nitric oxide release on light exposure was markedly reduced. Preincubation of cells with Roussin's black salt and subsequent measurement of levels of light-liberated nitric oxide demonstrated that the compound was rapidly internalised. The uptake of sodium nitroprusside was minimal. These data suggest that, in contrast to sodium nitroprusside, the cellular internalisation of Roussin's black salt allows site-directed nitric oxide release and very effective inhibition of cellular respiration. 相似文献
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以NaCl和KCl为熔盐,采用熔盐法合成了(La,Ce,Tb)PO4绿色荧光粉.利用XRD、SEM、激光粒度仪、光谱分析仪等测试和分析荧光粉物相、粒径、形貌及发光性能,主要考察了复合熔盐用量、合成时间及合成温度对荧光粉性能的影响,并对反应机理进行探讨.结果表明,复合熔盐与前驱体的摩尔比为2.5~3.5,在900 ℃保温3 h,可以得到性能良好的(La,Ce,Tb) PO4绿色荧光粉,其发光亮度优于高温固相法. 相似文献
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混合铜矿的常压氨浸与高压氨浸 总被引:2,自引:0,他引:2
对新疆某地的混合铜矿进行了常压氨浸和高氧压氨浸工艺研究,详细考察了NH3*H2O浓度、铵盐用量、氧化剂用量、氧压、浸出温度、浸出时间等因素对浸出过程的影响。结果表明,在常压、有氧化剂存在条件下,铜浸出率仅达到74.56%,而在高氧压条件下,铜的浸出率可达到98%。 相似文献
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本文针对上海某厂燃气盐浴炉存在的能耗高、钢包寿命短等问题,提出用群体盐浴炉系统代替单体盐浴炉,用平焰烧嘴代替火炬式烧嘴,用异型复合砖代替重质实心粘土砖,取得较好的节能效果,并延长了包子的使用寿命。 相似文献
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Exposure to a solution composed of an odor (almond) and a taste (salt) produced a context-independent preference when rats were subsequently tested with almond under a salt appetite. Postcompound exposure to either the almond or the salt alone reduced almond preferences but only when rats were tested in the extinction context. Exposure to either the almond or the salt in 1 context in advance of exposure to the compound in a different context also reduced preferences but only when the rats were tested in the context in which the element had been pre-exposed. These results show that extinction and latent inhibition of within-event learning are context specific. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献