玉米秸秆稀酸预水解液两种脱毒方法的研究

以玉米秸秆稀酸预水解液为原料,研究了减压蒸发和络合萃取两种脱毒方法对乙酸等抑制物的去除情况。结果表明:玉米秸秆稀酸预水解液减压蒸发脱毒,糠醛完全被去除,而5-羟甲基糠醛则基本不能被去除;当水解液浓缩5.80倍时,其浓缩液中乙酸质量浓度和去除率分别为4.06 g/L和60.45%。络合萃取脱毒的最佳条件:络合萃取剂的组成为30%三烷基胺+50%正辛醇+20%煤油,油水相比2∶1,温度25℃,时间60 min,此时脱毒液中乙酸质量浓度和去除率分别为1.43 g/L和52.33%,糠醛完全被去除,5-羟甲基糠醛的去除率为27.78%。     

玉米秸秆水热法催化液化研究

利用玉米秸秆为原料研究其在高压反应釜中的水热法液化过程.结果表明,反应温度为390℃,反应停留时间为15 min左右,升温速率为10℃min-1时,,生物油的得率最高.生物油的热值较高,成分也比较复杂.生物质的水热法液化能获得高能量密度产物,是一种具有良好发展前景的生物质转化技术.     

两表面层铁电薄膜体介质层效应理论研究

基于横场伊辛模型的平均场近似理论,研究了具有两个表面层铁电薄膜的体介质层对整个铁电薄膜相变性质的影响.给出了一个适合于研究任意层数具有两个表面层及体介质层铁电薄膜相变性质的递归公式.研究了体介质层的交换相互作用参量和横场参量对整个铁电薄膜相图的影响,以及交换相互作用参量对横场参量过渡值的影响和横场参量对交换相互作用参量的影响.结果表明,相图中铁电区、薄膜的居里温度、体介质层的横场参量过渡值均随体介质层的交换相互作用参量的增大而增大;体介质层的交换相互作用参量随体介质层的横场参量的增大而增大;而相图中铁电区、薄膜的居里温度却随体介质层的横场参量的增大而减小,并且发现体介质层的交换相互作用参量对薄膜的影响比其横场参量稍大些.最后也给出了两个表面层的交换相互作用对相图的影响.     

厚胶光刻非线性畸变的校正

利用厚胶光刻技术制作大深度微结构元件是一种有效的途径,但厚胶光刻过程中的非线性畸变对光刻面形质量的严重影响限制了该技术的应用,基于此,提出了一种对掩模透射率函数进行校正的方法。分析空间像形成及其在光刻胶内传递、曝光、显影等过程中非线性因素的影响,利用模拟退火算法对掩模透射率函数进行校正,以提高光刻面形质量,并以凹面柱透镜为例,给出了校正前后的显影轮廓模拟结果,其校正后浮雕面形的体积偏差仅为2.63%。该方法在有效改善面形质量的同时,并没有引起掩模的设计、制作难度及费用增加,这对于设计、制作高质量的微结构元件有重要意义。     

Effect of Cactus (Opuntia ficus-indica) and Acacia (Acacia seyal) Gums on the Pasting,Thermal, Textural,and Rheological Properties of Corn,Sweet Potato,and Turkish Bean Starches

This study was planned to explore the locally available natural sources of gum hydrocolloids as a natural modifier of different starch properties. Corn (CS), sweet potato (SPS), and Turkish bean (TBS) starches were mixed with locally extracted native or acetylated cactus (CG) and acacia (AG) gums at 2 and 5% replacement levels. The binary mixtures (starch–gums) were prepared in water, freeze dried, ground to powder, and stored airtight. A rapid viscoanalyzer (RVA), differential scanning calorimeter (DSC), texture analyzer, and dynamic rheometer were used to explore their pasting, thermal, textural, and rheological properties. The presence of acetylated AG or CG increased the final viscosity (FV) in all three starches when compared to starch pastes containing native gums. Plain SPS dispersion had a higher pasting temperature (PT) than CS and TBS. The addition of AG or CG increased the PT of CS, SPS, and TBS. The thermograms revealed the overall enthalpy change of the starch and gum blends: TBS > SPS > CS. The peak temperature (T_p) of starches increased with increasing gum concentration from 2 to 5% for both AG and CG native and modified gums. When compared to the control gels, the addition of 2% CG, either native or modified, reduced the syneresis of starch gels. However, further addition (5% CG) increased the gels’ syneresis. Furthermore, the syneresis for the first cycle on the fourth day was higher than the second cycle on the eighth day for all starches. The addition of native and acetylated CG reduced the hardness of starch gels at all concentrations tested. All of the starch dispersions had higher G′ than G″ values, indicating that they were more elastic and less viscous with or without the gums. The apparent viscosity of all starch gels decreased as shear was increased, with profiles indicating time-dependent thixotropic behavior. All of the starch gels, with or without gums, showed a non-Newtonian shear thinning trend in the shear stress vs. shear rate graphs. The addition of acetylated CG gum to CS resulted in a higher activation energy (Ea) than the native counterparts and the control. More specifically, starch gels with a higher gum concentration (5%) provided greater Ea than their native counterparts.     

Preparation of Highly Stable and Photoluminescent Cadmium-Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay

Indium phosphide (InP) quantum dots (QDs) are ideal substitutes for widely used cadmium-based QDs and have great application prospects in biological fields due to their environmentally benign properties and human safety. However, the synthesis of InP core/shell QDs with biocompatibility, high quantum yield (QY), uniform particle size, and high stability is still a challenging subject. Herein, high quality (QY up to 72%) thick shell InP/GaP/ZnS core/shell QDs (12.8 ± 1.4 nm) are synthesized using multiple injections of shell precursor and extension of shell growth time, with GaP serving as the intermediate layer and 1-octanethiol acting as the new S source. The thick shell InP/GaP/ZnS core/shell QDs still keep high QY and photostability after transfer into water. InP/GaP/ZnS core/shell QDs as fluorescence labels to establish QD-based fluorescence-linked immunosorbent assay (QD-FLISA) for quantitative detection of C-reactive protein (CRP), and a calibration curve is established between fluorescence intensity and CRP concentrations (range: 1–800 ng mL⁻¹, correlation coefficient: R² = 0.9992). The limit of detection is 2.9 ng mL⁻¹, which increases twofold compared to previously reported cadmium-free QD-based immunoassays. Thus, InP/GaP/ZnS core/shell QDs as a great promise fluorescence labeling material, provide a new route for cadmium-free sensitive and specific immunoassays in biomedical fields.     

玉米秸秆纤维复合缓冲包装材料的研究

研究了以聚醚多元醇、聚异氰酸酯为基体,以玉米秸秆纤维为增强体的新型复合缓冲包装材料,通过控制玉米秸秆纤维的添加量、发泡剂用量、交联剂与催化剂用量、反应温度等工艺参数,实验制备了具有可降解性能的缓冲包装材料,并利用静态压缩实验方法对比了该材料与发泡聚苯乙烯的缓冲性能.     

我国燃料乙醇生产技术的现状与展望

概述了目前国内外燃料乙醇产业现状.结合我国中粮生化能源(肇东)有限公司燃料乙醇装置,重点介绍了我国目前的燃料乙醇生产工艺技术水平、特点以及与国外的差距.本文从提高燃料乙醇生产技术水平、降低生产成本、寻找廉价非粮原料和开发新生产工艺等几个方面,对燃料乙醇生产技术的发展作了展望.     

粮食中玉米赤霉烯酮和镰刀菌氧萘满酮高效液相色谱分析方法的研究

建立了粮食样品中镰刀菌氧萘满酮（ＴＤＰ－１）和玉米赤霉烯酮（ＺＥＡ）的高效液相色谱－荧光检测分析方法。粮食样品在碱性和中性条件下用乙腈－水（３：１,Ｖ／Ｖ）提取,经正己烷脱脂,过Ｆｌｏｒｉｓｉｌ柱净化,最后用反相高效液相色谱－荧光检测法测定。该法的最低检出灵敏度：玉米赤霉烯酮为５×１０＾－９ｇ,镰刀菌氧萘满酮为１×１０＾－９ｇ。玉米中镰刀菌氧萘满酮和玉米赤霉烯酮的回收率分别为１００．２％和９２．４     

Production of 2,3- butanediol from pretreated corn cob byKlebsiella oxytoca in the presence of fungal cellulase

A simple and effective method of treatment of lignocellulosic material was used for the preparation of corn cob for the production of 2,3-butanediol byKlebsiella oxytoca ATCC 8724 in a simultaneous saccharification and fermentation process. During the treatment, lignin, and alkaline extractives were solubilized and separated from cellulose and hemicellulose fractions by dilute ammonia (10%) steeping. Hemicellulose was then hydrolyzed by dilute hydrochloric acid (1%, wJv) hydrolysis at 100°C at atmospheric pressure and separated from cellulose fraction. The remaining solid, with 90% of cellulose, was then used as the substrate. A butanediol concentration of 25 g/L and an ethanol concentration of 7 g/L were produced byK. oxytoca from 80 g/L of corn cob cellulose with a cellulase dosage of 8.5 IFPU/g corn cob cellulose after 72 h of SSF. With only dilute acid hydrolysis, a butanediol production rate of 0.21 g/L/h was obtained that is much lower than the case in which corn cob was treated with ammonia steeping prior to acid hydrolysis. The butanediol production rate for the latter was 0.36 g/L/h.