以蚕蛹为主要原料制曲工艺的研究

以蚕蛹为主要原料,通过对米曲霉的培养筛选,确定了沪酿3.042是最佳的菌种.研究了培养时间、温度、曲料含水量、碳源、碳源添加量和接种量对制曲的影响.结果表明,当培养时间72h,培养温度30℃,曲料含水量40%,接种景为0.5%,以葡萄糖为主要碳源时,米曲霉产中性蛋白酶为2135U/g,孢子数为1.92×1099个/g,氨基酸态氮为1.212g/100g.制曲后蚕蛹的风味得到极大改善.     

瞬态温度变化对大口径光学元件的影响

温度瞬变是影响惯性约束聚变(ICF)驱动器中大口径光学元件结构稳定性的一个重要的激励因素.采用多通道高精度温度监测仪对原型装置中编组站大口径光学元件环境温度进行了24 h监测,得到了编组站光学元件环境温度24 h温度变化曲线;采用有限元分析软件建立了光学元件的有限元模型,把温度监测结果作为载荷,对光学元件进行了热结构耦合分析.分析得到了大口径光学元件面形在24 h内的变化曲线,光学元件环境温度24 h内最大变化范围为0.45 ℃,24 h光学元件最大转角变化为1.12 μrad.分析结果表明,光学元件转角最大变化已超过打靶对光学元件稳定性的要求,但通过调整打靶时间,缩短光路准直之后打靶的等待时间可有效提高打靶的成功率.     

10 Gb/s OEIC optical receiver front-end and 3.125 Gb/s PHEMT limiting amplifier

A 10 Gb/s OEIC (optoelectronic integrated circuit) optical receiver front-end has been studied and fab ricated based on the φ-76 mm GaAs PHEMT process; this is the first time that a limiting amplifier (LA) has been designed and realized using depletion mode PHEMT. An OEIC optical receiver front-end mode composed of an MSM photodiode and a current mode transimpedance amplifier (TIA) has been established and optimized by simu lation software ATLAS. The photodiode has a bandwidth of 10 GHz, a capacitance of 3 fF/μm and a photosensitive area of 50×50 μm~2. The whole chip has an area of 1511×666 μm~2. The LA bandwidth is expanded by spiral inductance which has been simulated by software HFSS. The chip area is 1950×1910μm~2 and the measured results demonstrate an input dynamic range of 34 dB (10-500 mVpp) with constant output swing of 500 tnVpp.     

掺铒钨碲酸盐玻璃光谱性质的研究

研究了掺铒钨碲酸盐玻璃的吸收光谱和荧光光谱。应用JuddOfelt理论计算了Er3+的光谱强度参数Ωt(t=2,4,6)、自发辐射跃迁几率、荧光分支比和辐射寿命。从光谱强度参数的计算说明掺铒钨碲酸盐玻璃中Er—O键的共价性强于碲酸盐玻璃中Er—O键的共价性。玻璃的荧光半高宽为52nm,大于Er3+在磷酸盐和硅酸盐玻璃中的荧光半高宽。应用McCumber理论,计算了钨碲酸盐玻璃中Er3+离子在峰值波长1532nm的受激发射截面,为0.91×10-20cm2,大于Er3+在碲酸盐玻璃中的受激发射截面0.75×10-20cm2。由于掺铒钨碲酸盐玻璃的玻璃转变温度高、有较大的声子能量、较宽的荧光半高宽和较大的受激发射截面,是制作高增益的光波导放大器的理想材料。     

羟基改性的多壁碳纳米管接枝聚氨酯泡沫的制备及性能研究

采用原位聚合法制备了表面羟基化多壁碳纳米管（MWCNT）接枝聚氨酯(PU)泡沫复合材料。采用超声处理使MWCNT在聚醚多元醇中均匀分散,原位聚合可以改善MWCNT与PU材料间的界面效应。结果表明,当MWCNT含量小于0.4 %（质量分数,下同）时,PU泡孔形态稳定,分布均匀且泡孔尺寸较小,并观察到泡孔壁网状结构间出现膜状结构;当MWCNT含量大于0.6 %时,泡孔尺寸明显变大甚至出现泡孔塌陷;复合材料的回弹性、拉伸强度和断裂伸长率均随MWCNT含量的增加呈先增加后降低的趋势;复合材料的溶剂吸附能力随MWCNT的引入对不同溶剂产生了不同的影响,极性溶剂水的吸附摩尔数随着MWCNT含量的增加而降低,非极性溶剂石油醚的变化规律则相反。     

Enhanced luminescence in Tb3+-doped germanate glass ceramic scintillators containing CaF2 nanocrystals

Tb³⁺-doped germanate glass ceramics containing CaF₂ nanocrystals were prepared by melt quenching method with subsequent heat treatment. Their microstructures were investigated by XRD and TEM techniques. Their optical properties were studied by the transmittance, the photoluminescence, and the X-ray excited luminescence (XEL). The luminescence intensity in the glass ceramics under 377 nm light and X-ray excitations is significantly enhanced. The maximum integrated XEL intensity of the glass ceramics is about 50% of that of the commercial Bi₄Ge₃O₁₂ (BGO) scintillating crystal. The results indicate that Tb³⁺-doped germanate glass ceramic could be a promising scintillating material used in X-ray detection for slow event.     

基于优化BP神经网络的铝箔封口检测研究

提出一种高效率和高精度的铝箔封口完整密封性检测方法。首先,通过红外线热像仪获取铝箔封口处的热像图,然后利用MATLAB软件批量获取热像图的信息,再对其进行图像预处理。随后用遗传算法对BP神经网络进行优化,进行图像特征提取与分类识别。实验结果证明,此密封性检测方法识别率高、训练时间短,为后续的铝箔封口生产线中的密封不良产品自动筛选和剔除提供了保证。     

锰渣复合蛋壳粉对混凝土力学性能的影响

为解决锰渣和蛋壳对环境造成的污染问题,为实现锰渣和蛋壳资源的回收利用。本文对锰渣和蛋壳粉对混凝土的力学性能的相关影响进行了实验探究。在保证混凝土抗折抗压强度均大于对照组的情况下,实验得出了混凝土中可掺入的锰渣和蛋壳粉的最合适掺量:锰渣复合蛋壳粉掺入时,因养护龄期的不同,蛋壳粉的最佳掺量分别为3%和5%;蛋壳粉掺量为0时,锰渣的最佳掺量为5%,最大掺量为10%。