超声波辅助乙醇提取苦荞酒酒糟及底锅水总黄酮工艺优化

采用超声波辅助乙醇提取法探讨了未经蒸煮的苦荞、蒸煮过的苦荞、苦荞酒酒糟和"苦荞酒酒糟+底锅水"中总黄酮含量,得出苦荞酒酒糟及底锅水中总黄酮含量最高,并以此为研究对象,探究了苦荞黄酮提取的最佳工艺。在单因素试验的基础上结合正交试验,分别考察了乙醇体积分数、萃取温度、萃取时间和固液比对总黄酮含量的影响。得出较优的提取方案为:乙醇体积分数为85%、萃取温度为40℃、萃取时间55 min、固液比1∶45(g∶mL)。在最优的条件下,得出苦荞酒酒糟及底锅水中总黄酮含量为55.49 mg/g。结果表明,超声波辅助乙醇提取能明显提高苦荞酒酒糟及底锅水中黄酮的提取率,并为以后苦荞黄酮的提取提供了参考。     

Microstructure, Mechanical Properties and Oxidation Behavior of a Hot-Extruded TiAl Containing Ta

对热挤压后新型Ti Al合金Ti-46.5Al-3Ta-2Cr-0.2W的微观结构,力学性能及氧化行为进行了研究。结果表明,该合金挤压后微观组织主要由γ和α2相组成近片层组织,其片层晶粒尺寸为50~70μm。通过不同冷却速率获得了等轴,近片层及全片层的结构,尤其是在油淬后的组织中发现了大量的块状相。拉伸试验结果表明,挤压后的合金室温屈服强度和抗拉伸强度分别从807和846 MPa,降至800℃的620和760 MPa,而其伸长率从2.16%提高至3%左右,说明该合金在高温条件下依然具有较高的强度。断口观察表明,与其他合金相比,该合金的裂纹长度较小,而且Ta的添加有利于合金塑性的提高。最后对新型Ti Al基合金在800℃氧化行为进行了讨论,发现Ta的加入可以降低氧在Ti Al合金的溶解度,同时因其本身具有低的扩散率,在升高温度时能抑制Ti O2的生长。     

FABRICATION AND PROPERTIES OF CERAMIC CEMENTED CARBIDE COMPACT INSERTS

１．ＩｎｔｒｏｄｕｃｔｉｏｎＭｅｔａｌｃｕｔｔｉｎｇｉｓｔｈｅｗｉｄｅｓｔｍａｃｈｉｎｉｎｇｍｅｔｈｏｄｉｎｍｅｃｈａｎｉｃａｌｉｎｄｕｓｔｒｙｔｏｄａｙａｎｄｃｕｔｔｉｎｇｔｏｏｌｓｐｌａｙａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｗｈｉｃｈ．Ｉｔｉｓｏｎｅｏｆｔｈｅｆａｃｔｏｒｓｔｈａｔｄｅｔｅｒｍｉｎｅｔｈｅｃｕｔｔｉｎｇｓｐｅｅｄａｎｄｍｅｔａｌｃｕｔｔｉｎｇｒａｔｅ．Ｃｅｒａｍｉｃａｎｄｃｅｍｅｎｔｅｄｃａｒｂｉｄｅａｒｅｔｗｏｖｅｒｙｉｍｐｏｒｔａｎｔｋｉｎｄｓｏｆｃｕｔｔｉｎｇｔｏｏｌｍａ…     

缓冲器对某型遥控武器站炮口扰动的影响

为减小某型遥控武器站连续射击时的炮口扰动,提高其射击精度,建立了一种遥控武器站动力学模型,对其缓冲器进行研究。按照炮身运动环4个阶段建立了运动微分方程得到炮身运动诸元以及缓冲簧的受力情况,并通过三维建模软件SolidWorks以及动力学分析软件RecurDyn,在缓冲器不同刚度、阻尼和预压力等条件下,对遥控武器站进行了连续射击的动力学仿真。该研究获得了炮口振动特性曲线,掌握了缓冲器对武器站连续射击炮口扰动的影响规律。     

Relationship between dam's age at bull's birth and bull's genetic evaluation

After accounting for year of birth of bulls, younger dams produced superior sons. Bulls' PD, parent average, and pedigree index milk decreased with increasing age of dams at bull's birth. This appears to be due to decrease in maternal grandsire's PD milk and dam's Cow Index milk with increase in age of dam. Younger dams have an advantage of potentially higher genetic merit due to genetic trend but have less information included in their evaluations. Bull's latest parent average and pedigree index overestimated latest PD milk. This overestimation was not different with age of dam at bull's birth, suggesting that the bias in predicting bulls' PD from eventual evaluations of dams chosen at a younger age is not different than for dams chosen at a later age. Data were for 2826 bulls sampled by four AI organizations and born between 1965 and 1981. The increase in PD milk of bulls was about 27 kg/yr, but the trend was larger (45 kg/yr) during the last 5 yr. Inclusion of dam's age did not improve prediction of bull's PD milk. Maternal grandsire's PD milk was the primary variable associated with dam's age that accounted for lower bull's PD milk, mainly because older dams tended to have sires of lower genetic merit.     

采用模糊控制的糖厂中和与澄清过程PH值计算机控制系统

糖厂中和与澄清过程的ＰＨ值控制，一直以来是个难以解决的问题，这不仅由于在恶劣的生产环境下在线准确地测量蔗汁的ＰＨ值存在许多困难，而且由于蔗汁的ＰＨ值受多种种因素的影响，被控对象存在着大的惯性与滞后，给ＰＨ值的稳定控制带来了相当大的难度。着重从控制方法和应用效果两方面介绍了作者近来研制的糖厂中和与澄清过程ＰＨ值计算机控制系统。     

THERMAL and PHYSICAL PROPERTIES of TORTILLA CHIPS AS A FUNCTION of FRYING TIME

The objective of this study was to determine the thermal conductivity, specific heat, density (true and bulk), and the texture characteristics of tortilla chips and to study the effects of moisture content, oil content, and frying time on these properties. Tortilla chips were fried in fresh soybean oil for different times at 190C. Results showed that the values of thermal conductivity of tortilla chips decreased from 0.23 to 0.09 W/mC, specific heat from 3.36 to 2.31 kJ/kgC, and bulk density from 880 to 579 kg/m³ as frying time increased. In general, the crispness of tortilla chips increased as frying time increased.     

提高黑曲糖化酶活力的研究——菌种选育

使用DES、γ射线、5-FU、NTG等诱变处理黑曲霉A·S·3.4309,获得高产变异株7E-19-12,糖化酶活力比初始菌株提高100.6%,用30001发酵罐验证,其酶活力达9300 u/ml,并且2淀粉酶,酸性蛋白酶,转移葡萄糖甘酶含量较低。     

图形图像制作软件中的色彩模式分析

色彩模式是在数字处理过程中处理色彩的基本标准,其是以颜色模型为基础,利用数字定量对颜色进行描述的方法.针对图形图像制作软件中的色彩模式进行分析.     

光伏系统中Boost变换器的研究

在光伏发电系统中,前级升压变换器多采用Boost变换器,传统电压控制方式存在动态响应速度慢,系统稳定性差的缺点,针对上述问题,对原电路连续工作下的两种工作状态进行小信号建模,然后通过仿真得到Bode图,根据bode图设计了该控制环路的反馈补偿网络。最后,仿真和实验验证了小信号模型和补偿网络的正确性和有效性。