不同结合系统刚玉-方镁石-尖晶石浇注料的性能

对比研究了水泥结合和水合氧化铝结合的刚玉 -方镁石 -尖晶石浇注料的性能。结果表明 :二者相比 ,水合氧化铝结合浇注料的需水量较大 ,流动性较差 ,烧结致密化温度高 ,在 1 5 5 0℃下烧结后的强度和致密度低 ,但其抗热震性能及抗渣性能较好。     

考虑结算规则的多尺度市场耦合下梯级水电站中期运行风险分析方法

因为径流时空分布不均和不确定性,水电、火电为主的电力市场之间存在极大的不同,如何评估梯级水电参与电力交易风险是亟待解决的问题。该文结合西南某水电居主导地位的电力市场交易规则,构建了耦合月度交易和日前增量交易的梯级水电站参与市场交易的风险分析方法:采用Copula-Monte Carlo方法生成日径流和日前增量交易出清电价的组合场景,利用增强精英保留策略遗传算法计算所有场景的发电收益,获得给定置信水平下相应的条件风险价值。提出的方法综合考虑了径流、电价的不确定性,也计及了结算规则中各交易品种结算顺序和偏差考核标准,能直观求解收益风险值,过程简单、物理意义明确。以某电网梯级水电参与电力市场的实际资料为例,进行结果的仿真分析,结果表明所提方法可方便地求解交易组合风险价值,与单独考虑电价和径流相比能更合理的评估收益风险价值。     

溅射NdFeB薄膜合金的磁各向异性SCIEI

用RF溅射方法在不同的基片温度下制备了非晶态和晶态NdFeB溥膜合金。研究了薄膜合金的磁各向异性。在600℃溅射得到的晶态样品具有强的垂直各向异性和高的矫顽力。由非晶态晶化得到的晶态合金也呈现了较强的垂直各向异性。     

高炉型熔渣中TiO2的活度

在1500℃下用金属Sn作熔剂,石墨作还原剂,采用“熔渣—金属Sn”化学平衡法和相图计算法,得到了高炉型熔渣中TiO_2的活度,并讨论了渣中TiO_2的活度和活度系数随其浓度变化的规律。     

非晶Nd6Fe81B13合金的晶化和磁性

本文研究了非晶Nd_6Fe_(81)B_(13)合金的磁性和晶化及其对样品结构和磁性的影响。讨论了非晶样品的低温磁性和Nd对昌化温度和Curie温度的影响。在873K退火的样品中得到一个新相。     

多频超声波辅助磷脂酶处理对菜籽油脱胶效果及品质的影响

采用多频超声波技术对菜籽油的酶法(磷脂酶A1)脱胶效果及其脱胶后油品质变化展开了相关研究。结果表明,多频超声波作用能有效地提高磷脂酶A1对菜籽油的脱胶效率,大幅度降低脱胶后菜籽油中的含磷量;并且20/50 kHz双频超声处理对菜籽油的脱胶效果最佳。与磷脂酶A1脱胶后菜籽油相比,超声波作用后的脱胶油酸价和过氧化值略有上升(均在国家标准所规定的安全范围内),色泽变浅,脂肪酸组成的数值变化不明显。     

Dielectric Pretreatment of Rapeseed 1: Influence on the Drying Characteristics of the Seeds and Physico-chemical Properties of Cold-Pressed Oil

The aim of this study was to explore the effect of dielectric pretreatments on the drying characteristics of rapeseeds and physico-chemical attributes of cold-pressed rapeseed oil. Rapeseeds were adjusted to moisture contents of 15% and underwent dielectric pretreatments prior to oil extraction by cold pressing at frequencies of 27, 915, and 2450 MHz for 45, 30, and 22 min, respectively. Results showed that 2450 MHz dielectric heating had the highest temperature rising rate but the most nonuniform temperature distribution. Compared to the control samples, oil extraction yields were increased by 12.28, 17.25, and 22.08% for 27, 915, and 2450 MHz dielectric pretreatments, respectively. The SEM analysis indicated that the cell structures of pretreated rapeseed samples were severely damaged, thereby improving the extraction efficiency. Additionally, dielectric pretreatments significantly increased the total tocopherol content and improved the oxidative stability of cold-pressed oil (p <?0.05). The oil extracted from the 27-MHz pretreated rapeseeds exhibited lower acid and peroxide values and less color change, indicating better quality is achieved. Regarding fatty acid (FA) composition of the oils, oleic acid slightly increased and docosenoic acid decreased, but the total FA composition was not altered significantly by dielectric pretreatments (p >?0.05). These results suggested that dielectric pretreatment, a promising and environment-friendly technique, could be useful in the food industry for oil extraction.     

Magnetic Properties and Intergranular Action in Bonded Hybrid Magnets

Magnetic properties and intergranular action in bonded hybrid magnets,based on NdFeB and strontium ferrite powders were investigated.The long-range magnetostatic interaction and short-range exchange coupling interaction existed simultaneously in bonded hybrid magnets,and neither of them could be neglected.Some magnetic property parameters of hybrid magnets could be approximately obtained by adding the hysteresis loops of two magnets pro rata.     

The Effect of Surface Etching and Dation on the Permeability Spectrum of Nanocrystalline Fe_(85-x)Co_xNb_7B_8 Ribbon

Etching and oxidation were adopted to improve the frequency dependence of permeability of nanocrystalline Fe85-xCoxNb7B8 ribbons. The effect of etching and oxidation on the permeability spectrum of nanocrystalline Fe85-xCoxNb7B8 ribbons was investigated. The relaxation frequency shifted to higher frequency end after etching and oxidation while the amplitude of μi was reduced at the same time. As a whole, μif0 rises and reflects the increasing of resistivity after etching and oxidation.     

非均匀粘弹介质中有限元地震数字模型

本文讨论了粘弹介质的地震波响应。假定介质为块状,且块中纵,横波速度及密度、品质因数横向分段线性连续变化。在此条件下,给出了粘弹波动方程制作时间剖面的数学模型,导出了相应的有限元方程并给出其计算方法(包括刚度矩阵、阻尼矩阵)。模拟某实际水平叠加剖面的仿真结果,展示了该方法的效果和水平。