Effects of Cr and Cr/Mn Combined Additions on Semi-Solid Microstructures of Al-Mg-Si Alloys Produced by D-SSF Process

The effects of Cr and Cr/Mn combined additions on the semi-solid microstructure of wrought Al-Mg-Si alloys are investigated.In the Cr-added alloy,the Al-7Cr compound is formed with homogeneously distributed in theα-Al matrix after homogenization.Both of the Al-7Cr andα-Al-（12）Mn3-Si-2 dispersiod particles are found in the homogenized microstructure of the Cr/Mn-added alloy.In the semi-solid microstructures,the smallestα-Al grains are obtained in the 60% cold-rolled alloys.After prolonged holding time,theα-Al grain size of the Cr/Mn-added alloy is smaller than that of the Cr-added alloy.Heavy deformation by cold-rolling accelerates spheroidization of theα-Al grains.The D-SSF process is found to be useful to modify the microstructures of both the Cr-added and Cr/Mn-added Al-Mg-Si alloys.

植物纤维的水解与SSF过程的数学模型

采用一种植物纤维木糖渣为原料，对纤维素酶水解及同时糖化和发酵（ＳＳＦ）过程 进行了研究．研究结果表明，在纤维素含量为４２ｇ·Ｌ－１、纤维素酶的加入量为２８０ＦＰＩＵ·Ｌ－１、乳 酸菌用量为０．５ｇ·Ｌ－１时，乳酸对纤维素的转化率可达８０％．并从反应机理及动力学角度出发， 建立了纤维素酶水解与ＳＳＦ过程的数学模型．

玉米酒精的浓醪同步糖化发酵工艺研究

以我国目前玉米酒精生产工艺为基础,通过选择液化[拌料干物浓度(dry solid,DS)、液化pH、液化时间、耐高温α-淀粉酶剂量、液化温度]和同步糖化发酵(葡萄糖淀粉酶剂量、酵母接种量、发酵温度等)等过程主要控制参数建立实验室玉米酒精发酵方法。实验确定液化条件为拌料DS 25%、液化pH 5.6、液化时间120 min、耐高温α-淀粉酶剂量40 U/g、液化温度88℃,此时液化醪黏度(91.2±2.8)mPa·s、还原糖为(11.65±0.03)g/100 g,符合同步发酵玉米酒精的液化指标要求。实验确定同步糖化发酵条件为葡萄糖淀粉酶剂量150 U/g、酵母接种量3%、发酵温度32℃,在该条件下酒精发酵过程稳定,CO 2失重数据最大标准差为0.38,占相应CO 2平均失重仅为2.96%;在发酵成熟醪中乙醇含量为(12.58±0.04)g/100 mL,发酵效率为97.71%,粮酒转化率为2.425 t/t,实验结果符合我国玉米酒精生产的实际情况。因此该方法可以为酒精生产工艺的优化及原辅料的选择提供数据参考。

植物纤维的水解与 SSF 过程的数学模型

采用一种植物纤维木糖渣为原料，对纤维酶水解及同时糖化和发酵（ Ｓ Ｓ Ｆ） 过程进行了研究。研究结果表明，在纤维素含量为４２ｇ· Ｌ１ 、纤维素酶的加入量为２８０ Ｆ Ｐ Ｉ Ｕ· Ｌ１ 、乳酸菌用量为０ ．５ｇ· Ｌ１ 时，乳酸对纤维素的转化率可达８０ ％ ，并从反应机理及动力学角度出发，建立了纤维素酶水解与 Ｓ Ｓ Ｆ 过程的数学模型。

Induced Production of Exoglucanase, and <i>β</i>-Glucosidase from Fungal Co-Culture of T. <i>viride</i>and G. <i>lucidum</i>

In the present study, a co-culture technique was adopted with an aim to investigate a hyper production of exoglucanase, and β-glucosidase using cheap and easily available agro-industrial residue corn stover as growth supporting substrate. Various physio-chemical and nutritional variables were optimized using classical and completely randomized designs for induced production of exoglucanase, and β-glucosidase from the co-culture of Trichoderma viride and Ganoderma lucidum in solid state fermentation (SSF). Analysis profile showed that when the conditions of the SSF medium containing 15 g corn stover substrate (50% w/w moisture) inoculated with 6 mL of inoculum were optimal, the maximum productions of exoglucanase (485 ± 6.5 U/mL) and β-glucosidase (255 ± 3.3 U/mL) were recorded after 5 days of incubation at pH 6 and 35°C.

饲料蛋白固态发酵过程参数的FT-NIR快速检测

为实现对整个固态发酵过程状态信息变量的在线监测,研究提出基于近红外光谱分析技术的饲料蛋白固态发酵过程参数快速检测新方法。利用近红外光谱采集装置获取固态发酵物样本的近红外光谱,引入不同的光谱预处理方法校正原始近红外光谱数据,采用PLS建立固态发酵过程参数pH和湿度的定量分析模型。在模型校正过程中,通过交互验证法优选光谱预处理方法和建模所需的主因子数。试验结果显示,pH和湿度的PLS模型在预测集中的相关系数R_p分别为0.9838和0.8707,RMSEP分别为0.0696和0.0152。研究结果表明,利用近红外光谱分析技术快速监测固态发酵过程参数是可行的。