响应面法优化碳热还原合成LiFePO4/C的工艺参数（英文）

A statistically based optimization strategy is used to optimize the carbothermal reduction technology for the synthesis of LiFePO4/C using LiOH,FePO4 and sucrose as raw materials.The experimental data for fitting the response are collected by the central composite rotatable design(CCD).A second order model for the discharge ca-pacity of LiFePO4/C is expressed as a function of sintering temperature,sintering time and carbon content.The ef-fects of individual variables and their interactions are studied by a statistical analysis(ANOVA).The results show that the linear effects and the quadratic effects of sintering temperature,carbon content and the interactions among these variables are statistically significant,while those effects of sintering time are insignificant.Response surface plots for spatial representation of the model illustrate that the discharge capacity depends on sintering temperature and carbon content more than sintering time.The model obtained gives the optimized reaction parameters of sinter-ing temperature at 652.0 ℃,carbon content of 34.33 g?mol-1 and 8.48 h sintering time,corresponding to a dis-charge capacity of 150.8 mA·h·g-1.The confirmatory test with these optimum parameters gives the discharge ca-pacity of 147.2 and 105.1 mA·h·g-1 at 0.5 and 5 C,respectively.     

响应面分析外加固化材料对滩涂淤泥早期强度的影响

通过响应面法研究粉煤灰、胶凝材料、氧化镁、TEA、固化剂FJ、固化剂KG对滩涂淤泥固化早期强度的影响。结果表明,粉煤灰和胶凝材料的交互作用对滩涂淤泥固化早期强度有显著影响。最优配方为:水泥基材料占淤泥干重19%,粉煤灰占淤泥干重20%,胶凝材料占水泥基材料22.4%,固化剂KG占水泥基材料30%。     

基于响应面法对制备高包埋率ROP-PLGA微球的影响因素分析

作为一种新型酰胺类局部麻醉药,罗哌卡因(ROP)被广泛用于术后的疼痛管理中.ROP半衰期短(t1/2=1.8h),临床上为满足患者的镇痛需求,常需多次给药,导致患者顺应性差.采用复乳-溶剂挥发法结合快速膜乳化技术制备ROP-PLGA微球,最终在外水相PVA浓度1.5％(w/v)、油相与外水相(O/W2)体积比1:7.5...     

重组大肠杆菌高密度发酵生产类人胶原蛋白的过程控制研究

Recombinant E. coli BL 21 was cultivated in high cell density to produce human-like collagen. The effects of the feeding of nitrogen source, controlled by an auto on/off-feeding mode with two different cycles of 0.5min and 4min intervals, oxygen-enrichment methods and inducement strength on the cell yield and human-like collagen production were investigated. The studies showed that nitrogen source feeding in fast cycle could result in higher human-like collagen production than that in slow cycle; and the feedback regulation of glucose, increase of the pressure of fermentation bioreactor, and supply of oxygen-enriched air could all increase cell yield and human-like collagen production. The effects of inducement strength on protein expression were found important. When OD600 reached 90-100, the cultivation temperature was increased to 42℃ to begin induction for 2-3 h, and then shifted to 39℃ for 5-6h induction, the cell density and human-like collagen production could reach 96g·L-1 [DCW (dry cell mass)     

种子扩大培养过程对类人胶原蛋白规模化生产的影响

为了建立最优的类人胶原蛋白(HLC)的种子扩大培养过程,考察了三级种子培养过程中不同移种阶段和不同种子培养基对发酵过程的影响。结果表明,在对数期后期移种,HLC产率最高;当种子培养基中葡萄糖浓度为20 g·L-1时,其后发酵过程所需的培养时间较短,HLC表达量较高,HLC平均产率最高,达到0.518 g·L-1·h-1...     

重组大肠杆菌分批-补料高密度发酵生产类人胶原蛋白的动力学

The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and growth rates were set at (0.15, 0.2, 0.25h-1) by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase spectively. The model predictions are in good agreement with the experimental data.     

基因重组大肠杆菌生产类人胶原蛋白补氮策略优化研究

优化重组大肠杆菌高密度发酵的调控工艺.利用重组大肠杆菌高密度发酵生产类人胶原蛋白,考察了连续流加和分阶段式两种不同补氮策略对细胞生长和类人胶原蛋白产量的影响.不同补氮方式显著影响类人胶原蛋白的产量.分阶段式补氮方式优于连续流加补氮方式,有利于细胞生长和类人胶原蛋白的表达,最终细胞浓度为76.01 g·L-1(DCW),类人胶原蛋白浓度为16.75 g·L-1,蛋白表达量为22.1%.     

重组大肠杆菌分批-补料高密度发酵生产类人胶原蛋白的动力学

The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and Yx/s were determined as 1.75h, 0.65h^-1 and 0.51g·g^-1, respectively. In the fed-batch culture, different specific growth rates were set at （0.15, 0.2, 0.25h^-1） by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase were obtained. The result shows that the concentrations of cell and product can reach 77.5g·L^-1 and 10.2g·L^-1 respectively. The modal predictions are in good agreement with the experimental data.     

响应面法优化疏水改性阳离子胶原蛋白絮凝剂的制备条件

以皮革废弃物提取的明胶为原料,丙烯酰胺（AM）、丙烯酰氧乙基三甲基氯化铵（DAC）和丙烯酸丁酯（BA）为单体（AM：DAC：BA摩尔比为80:18:2）,叔丁基过氧化氢和焦亚硫酸钠为引发剂,接枝共聚合成疏水改性阳离子胶原蛋白絮凝剂P(C-AM-DAC-BA)。以絮凝剂对油田模拟废水浊度去除率为指标,探讨m（明胶）：m（单体）、引发剂用量、接枝温度、接枝时间对絮凝效果的影响,通过响应面法优化得到P(C-AM-DAC-BA)接枝共聚最佳条件：m（明胶）：m（单体）为1:2.04、引发剂用量0.032mol/L、接枝温度49.2℃、接枝时间2.8h。在此条件下,P(C-AM-DAC-BA)对油田模拟废水浊度去除率为91.5%。     

响应面分析优化霉酚酸发酵培养基

借助Design Expert 7.0软件,对霉酚酸发酵培养基的主要成分进行优化研究。首先采用全因子设计找出玉米浆和蔗糖为影响霉酚酸产量的主要因素,通过最陡爬坡法逼近最大响应区域,再利用中心组合设计及响应面分析法进行回归分析,求得两因素的最优水平：玉米浆98 g/L,蔗糖53 g/L。经验证,发酵培养基优化后菌株产量提高了38.2%。     

响应面法优化东京野茉莉油制备生物柴油的工艺研究

研究了响应面法优化东京野茉莉油制备生物柴油的工艺。通过单因素实验,对影响转化率的四个主要因素:油醇摩尔比、催化剂用量、反应时间、反应温度进行考察,并根据Box-Behnken中心组合进行4因素3水平的实验设计,以东京野茉莉生物柴油转化率为响应值,进行响应面分析(RSA)。结果表明,东京野茉莉生物柴油的最佳工艺条件为:油醇摩尔比1∶8、催化剂用量为油质量的0.78%、反应时间2.2 h、反应温度60℃,理论转化率为95.81%。实际验证值为95.32%,理论值与实际值相对误差为0.49%,说明通过响应面法能得到一个预测试验结果的模型方程。以东京野茉莉油为原料通过酯化反应制取的生物柴油与0#柴油及国标GB/T 20828-2007主要性能相似,通过与石油柴油调和或添加降凝剂等方法,可改善低温流动性。     

Optimizing the Alcohol Precipitation of Danshen by Response Surface Methodology

Alcohol precipitation (AP) is a common method to achieve separation and purification in the process of food and herbal preparations. The response surface methodology (RSM) was applied to study and optimize the AP of Danshen, regarding the recovery of danshensu (RD) and the removal of saccharides (RS). A fractional factorial design was initially performed and solid content, ethanol consumption, acid consumption, and temperature showed significant influence on RD and RS. A Box-Behnken design with 28 experimental runs was then applied and two polynomial equations were established, based on which the effects of significant factors and their interactions were discussed. The optimum operating conditions were solid content at 66.0%, ethanol consumption at 4.3 mL/g, acid consumption at 0 g/g, and temperature at 10.7°C. The average experimental RD and RS under the optimum conditions were obtained to be 66.25 ± 1.01% and 61.64 ± 1.84%, respectively, which agreed well with the predicted values (68.85% for RD and 61.92% for RS).     

响应面法优化甘蔗糖蜜酸催化水解制备乙酰丙酸

在甘蔗糖蜜酸催化水解制备乙酰丙酸的过程中,以乙酰丙酸（levulinic acid, LA）产率为考察对象,在单因素实验基础上,考察了反应时间、糖蜜浓度、催化剂浓度比、反应温度的作用。采用Box-Benhnken中心组合试验原理和响应面分析法（RSM）对乙酰丙酸制备条件进行优化。结果表明,建立的二次多项式模型回归性显著而失拟项不显著,模型拟合性良好。各因素对LA产率有显著性影响,依次为：催化剂浓度比>反应温度>反应时间>糖蜜浓度。实验最终确定乙酰丙酸最佳制备条件为：反应时间5 h、糖蜜浓度40 wt%、催化剂浓度比23.40:1、反应温度151℃。该条件下进行三次重复试验,乙酰丙酸的实际平均产率为30.11 wt%,与预测值30.96 wt%相对偏差0.85 wt%,模拟可靠。