1549mm热连轧传动系统

介绍了由我国自行研制和设计的太钢1549mm热连轧机的电气传动系统,该系统采用了全数字直流传动和高压大功率晶闸管变流装置等多项新技术。采用该系统比引进国外同类型设备节约了8330万元。     

PEEK与CF/PEEK红外光谱检测及摩擦性能分析

为了了解掌握目前PEEK以及其增强复合材料的摩擦性能发展水平以及发展方向,本文对当前生产的PEEK以及CF/PEEK进行了基础性的研究和实验。首先采用红外线光谱测试了PEEK与CF/PEEK之间的成分差异。而后对材料进行了基础摩擦实验,分析了PEEK与CF/PEEK表面现象,由此对两者的摩擦机理及摩擦性能有了更进一步的升入了解。通过这些实验分析发现PEEK加入碳纤维之后吸收红外辐射引起的振动变化,以及PEEK和CF/PEEK的摩擦力矩与摩擦系数的变化趋势。对于今后PEEK的增强复合材料的研究具有指导意义。     

Preparation of nanometer oxides La1−xSrxMnO3 by absolute alcohol as solvent

Nanometer oxides La1-xSrxMnO3 were synthesized by absolute alcohol as solvent. The desired metal cations were chelated in a solution using citric acid as the chelating agents. In order to get the optimum preparation condition for Lal-xSrxMnO3, the pH of primal commix solution, the molar fraction of citric acid and baking temperature of predecessor block were researched by orthogonal test design method with different x. The thermal decomposition of the metal carboxylate precursor gels was studied by TG/DTA and the products derived from calcinations of the gels were characterized by XRD and TEM. The polarization curves were acquired on an electrochemical work station （LK98） and the discharge curves were acquired on a testing instrument of batteries （DC-5） with a constant current discharge under 120 mA/cm^2. The results reveal that the nanometer oxides can be achieved by absolute alcohol as solvent and it has better catalytic activity.     

混合导电体Y1-xLaxBa2Cu3O7-δ透氧膜的透氧性能研究

用稳态法研究了具有类钙钛矿结构的Y1-xLaxBa2Cu3O7-δ(x=0.1、0.3、0.5、0.8和1.0)致密透氧膜在750～1000℃之间的透氧量.实验发现,透氧速率随着La替代Y的比例x的增加而增加;在大约875℃,氧空位的有序-无序转变导致透氧率有一个突然增加.透氧膜的两侧分别为He气氛和空气,当La完全替代Y时,厚1.0mm的LaBa2Cu3O7-δ膜的透氧量达到1.22μmol/s.cm2(1.64 mL/min.cm2).     

Illumina MiSeq高通量测序技术研究原料乳冷藏过程中微生物群落演替规律

为探究原料乳在4℃冷藏过程中细菌群落及其演替规律,采用Illumina MiSeq高通量测序技术对乳罐中原料乳的细菌16S rDNA V4-V5区测序,对冷藏不同时间的细菌群落进行表征.结果表明,原料乳中的菌群随冷藏时间的变化而变化.整个冷藏期内,各样本共有OTU数29个,其中冷藏初期样本的特有OUT个数最多,为157...     

牛肉萨拉米香肠的工艺配方研究

萨拉米香肠常以猪肉为主要原料,是常见西式发酵肉制品之一,深受消费者喜爱。为丰富萨拉米口感,实验以牛肉为原料,开发牛肉萨拉米香肠。在传统工艺的基础上,单因素试验确定其最佳添加配方为精盐量2.50%、白砂糖0.60%、辣椒粉0.60%及发酵剂DCM-1 0.15g/kg。优化关键工艺参数:发酵温度(A)、发酵时间(B)、发酵剂DCM-1添加量(C)。采用Box-Behnken响应面分析法进行二次多项回归拟合,得到回归方程为:Y=93.80-1.75A-1.75B+2.00C+0.25AB-0.25AC-1.75BC-1.78A2-3.78B2-0.27C2;由回归模型分析,可知牛肉萨拉米香肠的最佳工艺参数为发酵温度36℃、发酵时间22h、发酵剂DCM-1的添加量0.20g/kg。验证试验表明,实际测定值与预测值的误差为3.14%,说明本产品稳定性良好,所得产品风味独特,切面肥瘦均匀、红白分明,淡酸微咸,符合萨拉米香肠的特点。