Pr0．5 La0．2 Sr0．3 MnO3的电磁性能及其庞磁电阻效应

锰氧化合物在计算机硬盘和磁头等领域有着广泛的应用。本实验用高温烧结法制备了半掺杂锰氧化合物Pr_(0.5)La_(0.2)Sr_(0.3)MnO_3陶瓷,测试结果表明,在温度从5K增加到300K的过程中,样品依次由反铁磁绝缘体转变为铁磁半导体、铁磁金属、顺磁半导体。在发生反铁磁-铁磁和铁磁-顺磁两种转变温度处,样品在较低的外加磁场作用下,都表现出了较强的庞磁电阻效应。     

干燥温度对谷朊粉膜性能的影响

干燥温度是影响谷朊粉可食性膜性能的一个重要因素．本文探讨了可食性谷朊粉膜制备过程中，采用真空干燥在不同的温度下进行时对膜透光率、水溶性、拉伸强度、断裂伸长率、水蒸气透过系数等性能的影响。试验结果表明：在60℃条件下干燥，膜的综合性能最好。     

不同温湿度对奶粉包装膜水蒸气透过率的影响

主要研究了不同温度(25~38℃)和湿度(RH35%~90%)对奶粉包装膜的水蒸气透过率的影响。试验结果表明,该奶粉包装膜在一定相对湿度时,水蒸气透过率随温度的升高而升高;在一定温度时,水蒸气透过率随相对湿度的升高而升高;温度越高,相对湿度越大,该奶粉包装膜的水蒸气透过率越大。     

温度对兑卤过程相关生产指标影响的相图分析及计算

盐湖兑卤生产光卤石(Car)时,温度往往会对兑卤固相物中的NaCl含量、Car的产率和Car的单产等生产指标产生影响.文章借助由"计算机"准确做出的相图,通过对相图进行分析及计算后,得出了有利于兑卤固相物生产的适宜温度.     

The Influences of Steeping Duration and Temperature on the α‐ and β‐Amylase Activities of Six Thai Rice Malt Cultivars (Oryza sativa L. Indica)

A preliminary study of malting conditions for six Thai rice cultivars was conducted. Three non‐glutinous rice cultivars (KDML105, PT60, and WR) and three glutinous rice cultivars (SPT, RD6, and KND) were selected. The steeping durations (24, 48, and 72 h) and temperatures (20, 25 and 30°C) were investigated for their effect on α‐ and β‐amylase, the key enzymes for malt quality evaluation. During steeping, the production of both enzymes was lower than at the germination process. The longer the steeping duration, the lower the maximum β‐amylase activity obtained. The contradictory effect was observed for α‐amylase activity, near the end of the germination time. Additionally, temperature influenced the water absorption content as well as the amylolytic enzyme activity. Particularly at 30°C, the maximum β‐amylase activity (6.7 unit/mg protein) was found in KND malt steeped for 24 h, and maximum α‐amylase activity (20 unit/mg protein) was found in PT60 malt steeped for 72 h. The amount of enzyme production depended on the variety rather than the amylose content in the rice. The optimal condition for malting rice regarding β‐amylase activity and α‐amylase activity was analyzed at 30°C, with steeping for 24 h and germination for 4–5 days.