一株芽孢杆菌破乳特性试验

为准确、高效地调控生物破乳菌对破乳活性物质的生产,采用自筛破乳菌Bacillus mojavensis sp.,以O/W型模型乳状液作为破乳对象,分别测定在不同培养时间,全培养液不同组分,以及不同碳、氮源的条件下对该菌破乳效能的影响情况.结果表明:培养时间在14～24h全培养液的破乳活性最高.全培养液和中层液破乳效能高,菌体不具备破乳能力.烃类碳源可诱发该破乳菌产生具有破乳活性的代谢产物,而碳水化合物可以促进破乳菌的生长,其中果糖+液体石蜡组成的混合碳源对破乳菌的生长和破乳效能最有利.混合氮源NH4NO3+酵母膏更适于该破乳菌的生长及破乳活性物质的产生.控制培养时间和碳源、氮源的种类,可有效调控该破乳菌代谢产物破乳活性的高低.     

生物复合型破乳剂破乳特性研究

为解决现有生物破乳剂破乳效率低、稳定性差、易受环境影响、难以大规模生产的问题,将具有破乳效果的莫海威芽孢杆菌（Bacillus mojavensis）、枯草芽胞杆菌（Bacillus subtilis）在改进的无机盐液体培养基中混合培养,得到了一种高效生物复合型破乳剂.生物复合型破乳剂全培养液在室温下,接触时间48h可...     

L—色氨酸产生菌分批发酵动力学模型

基于30L的发酵罐分批发酵实验数据，根据已建立的L－色氨酸发酵数学模型，应用MATLAB软件对模型进行最优参数估计和非线性曲线拟合，得到的结果相对误差较小，所建立的分批发酵动力学模型能较好地反映L－色氨酸分批发酵的过程。     

水酶法提取高油酸花生油的破乳及品质研究

水酶法提油是一种绿色环保的油脂提取方法,可以同时实现油脂和蛋白质的提取,但是在提取过程中容易产生稳定的乳状液,严重限制了水酶法提油在工业上的应用。以高油酸花生为原料,采用4种不同的破乳方法(物理法、化学法、酶法、盐法辅助微波)对水酶法提油过程中产生的乳状液的破乳效果进行了对比。结果表明:CaCl2辅助微波破乳具有最好的破乳效果,在390 W、30 s的条件下,破乳率达到(91. 87±1. 90)%。此外,对4种破乳方法提取的花生油的脂肪酸组成和品质进行了研究,发现花生油的脂肪酸组成无明显差异,且CaCl2辅助微波破乳提取的花生油品质优于常规加热破乳油。     

乳状液膜法分离Cr(Ⅵ)破乳方法的研究

研究了以三正辛胺、仲辛醇和磷酸三丁酯为载体,Span-80为表面活性剂,煤油为膜溶剂制成的乳状液膜处理含Cr(Ⅵ)水样的破乳方法,对离心破乳、化学破乳进行了实验研究,同时对破乳后的油相重新进行了制乳、破乳实验.实验结果表明,用破乳后的油相重新制乳,其Cr(Ⅵ)的提取率可达98%以上,再次破乳率可达90%以上.     

微波辐射辅助破乳水处理工艺

以某汽车发动机制造有限公司排放的铸铁乳化废水为处理对象,研制了新型破乳剂A并辅以微波辐射,解决了原破乳工艺中存在的破乳效果差,效率低,出水COD超标等问题。考查了微波辐射功率、辐射时间、静置时间以及废水pH值对破乳效果的影响,确定了最佳的破乳工艺条件:采用破乳剂A使废水pH值为2~3,在微波功率600 W下辐射处理1 min后,室温下静置1 h。在此工艺条件下,COD去除率高达70%以上。通过对水样初始COD值对破乳效果的研究,发现微波辐射处理乳化废水具有较好的耐冲击负荷的能力。通过对水样的粘度、油珠粒径分布z、eta电位等参数的分析考查,探讨了微波辅助化学破乳的反应机制。     

老化稠油破乳脱水实验研究

根据王集油田老化稠油含水状况及油品性质,进行破乳脱水实验研究.研究发现,单用破乳剂时破乳脱水困难,在加入一定量的脱水助剂FW后,其破乳脱水效果显著.研制的破乳脱水配方为破乳剂TY-1、TY-2、TY-3质量配比为4:2:1,用量为300×10-6,FW加量为0.9%,脱水效果较好.     

纳米颗粒在破乳领域的应用研究进展

为提高含油乳状液的破乳效率,降低破乳处理成本,减少破乳后处理对环境的破坏,纳米粒子(NPs)作为一种可控性强且具有多重优势的功能性材料在破乳领域引起关注.首先对磁性纳米粒子与非磁性纳米粒子在破乳中的机理进行了综述,为新型破乳剂的研发提供思路;其次分析并讨论了纳米粒子的制备方法及其应用;最后结合原油开采技术的发展,指出目...     

L-亮氨酸分批发酵动力学研究

通过检测发酵过程的基质浓度、菌体量和产物浓度,建立了一组反映TQ9806菌株L-亮氨酸分批发酵的动力学模型,结果显示该动力学模型可以很好的拟合发酵过程。     

嗜酸放线菌701深层发酵产纤溶酶动力学研究

以嗜酸放线菌701为菌株,在摇瓶培养条件下,研究嗜酸放线菌701产纤溶酶发酵过程中菌丝体生物量、纤溶酶生成量及残糖含量随时间的变化情况。采用Logistic和Luedekin_Piret方程,得到嗜酸放线菌701产纤溶酶的分批发酵动力学模型及模型参数,将实验数据与所得动力学模型进行验证比较,结果表明模型值与实验数据拟合性良好,模型基本可以反映嗜酸放线菌701分批发酵产纤溶酶的发酵动力学特征。     

CH3SiH3→CH4＋SiH2裂解反应的理论热力学、动力学分析

本文采用过渡态理论和量子化学计算方法,首次计算得到了甲硅烷裂解反应的速率常数和平衡常数,并对结果进行了讨论。     

Microstructure and microwave dielectric properties of CaO-B2O3-SiO2 glass ceramics with various B2O3 contents

The effects of B2O3 addition on both the sintering behavior and microwave dielectric properties of CaO-B2O3-SiO2 (CBS) glass ceramics were investigated by Fourier transform infrared spectroscopy (FTIR),X-ray diffractometry (XRD) and scanning electron microscopy (SEM).The results show that the increasing amount of B2O3 causes the increase of the contents of [BO3],[BO4] and [SiO4],which deduces the increase of CaB2O4 and α-SiO2 and the decrease of CaSiO3 correspondingly.No new phase is observed throughout the...     

Influence of addition of B2O3 on properties of Yb^3＋-doped phosphate laser glass

The three host glasses doped with Yb^3＋ were prepared by means of conventional melt quenching technology, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigated and compared with silicate glass. The results show that due to the existence of OH^- impurities which induce the non-radiative route, the fluorescence lifetime of phosphate glass is shorter, so silicate glass has better spectral properties than phosphate glass. Silicate glass has more excellent thermal-mechanical properties than phosphate glass, but with the addition of B2O3, thermal-mechanical properties of phosphate glass are improved greatly without fluorescence quenching effect, and this kind of borophosphate glass will be the candidate to be used in high average power solid state laser.     

锂离子电池负极材料 Na2Li2Ti6O14的嵌脱锂过程动力学研究

为了研究钛酸钠锂(Na2Li2Ti6O14)负极材料嵌脱锂的动力学行为,用溶胶-凝胶法合成 Na2Li2Ti6O14负极材料,采用 X 射线衍射法(XRD)和电子显微镜(SEM)分别对材料进行物相分析和微观形貌的观察.采用恒流充放电测试、循环伏安法(CV)和恒电流间歇滴定法(GITT)研究了 Na2Li2Ti6O14的电化学性能和嵌脱锂过程动力学.研究结果表明,制备的 Na2Li2Ti6O14材料纯度高,结晶度良好,循环稳定性好;由不同扫描速率的循环伏安法测出的 Na2Li2Ti6O14中锂离子在氧化、还原峰对应的化学扩散系数 Da和 Dc分别为7.3×10-11和7.8×10-11cm2/s;由恒电流间歇滴定技术测得的锂离子在 Na2Li2Ti6O14电极中的扩散系数为10-11~10-8cm2/s.     

Low-temperature sintering and microwave dielectric properties of Li2MgTi3O8 ceramics doped with BaCu（B2O5）

The influences of BaCu(B₂O₅) (BCB) addition on sintering, microstructure and microwave dielectric properties of Li₂MgTi₃O₈ ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements. The experimental results show that a small amount of BaCu(B₂O₅) addition can effectively reduce the sintering temperature to 900 °C, and induce only a limited degradation of the microwave dielectric properties. Typically, the best microwave dielectric properties of ɛ _r=24.5, Q×f =24 622 GHz, τ _f=4.2×10⁻⁶ °C⁻¹ are obtained for 1.0% BCB-doped Li₂MgTi₃O₈ ceramics sintered at 900 °C for 3 h. The BCB-doped Li₂MgTi₃O₈ ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications.     

Synthesis of nano-CaCo3 composite particles and their application

Nano-calcium carbonate composite particles were synthesized by the soapless emulsion polymerization technique of double monomers. The composite particles formation mechanism was investigated. The effects of composite particles on the mechanical properties of nano-CaCO3-ABS （acrylonitrile-butadiene-styrene copolymer） composite material were studied. It was validated that the composite particles are made up of the nano-calcium carbonate cores and the shells of alternating copolymers of butyl acrylate （BA） and styrene （St）. The shells are chemically grafted and physically wrapped on the surface of nano-calcium carbonate particles. When the composite particles were filled in ABS matrix, the CaCO3 particles are homogeneously dispersed in the composite material as nanoscales. The impact strength of the composite material is obviously enhanced after filling appropriate amounts of composite particles. It can be concluded that the soapless emulsion polymerization of double monomers is an effective method for nano-CaCO3 surface treatment. 2008 University of Science and Technology Beijing. All rights reserved.     

Kinetics of Fe3O4 formation by air oxidation

The kinetics of Fe₃O₄ formation by air oxidation of slightly acidic suspension of Fe(OH)₂ was studied. The effects of initial concentration of Fe(II), temperature, partial pressure of oxygen, air flow rate and stirring rate on the oxidation rate were investigated. The results show that Fe₃O₄ formation is composed of two-step reaction, the first step is the formation of Fe(OH) ₂ ⁺ by oxidation of Fe(OH)⁺ complex ions, the second step is the formation of magnetite by dehydration and deprotonation of Fe(OH)⁺ and Fe(OH) ₂ ⁺ . The oxidation reaction is zero-order with respect to the concentration of Fe(II) and around 0.5-order with respect to partial pressure of oxygen, and oxygen transfer process is rate-limiting step of oxidation reaction with apparent activation energy of 2.74 kJ · mol⁻¹.     

Comparative experiment on layered Li（Ni1/3Co1/3Mn1/3）O2 as the alternative material for LiCoO2

This work was financially supported by the National Natural Science Foundation of China （No.50472093）.