响应面法优化月桂酸单甘油酯的酶催化合成工艺

以月桂酸三甘油酯和甘油为原料,脂肪酶催化甘油解反应合成月桂酸单甘油酯。在单因素试验的基础上,采用响应面分析法进行合成工艺优化。结果表明,含水量(相对于甘油的质量)对月桂酸单甘油酯产率的影响最为显著,且较优合成条件为:恒温振荡器转速100 r/min,酶添加质量分数(相对于底物)5%,n(甘油)∶n(月桂酸三甘油酯)=6∶1,底物质量分数(相对于整个反应体系)51.9%,温度65℃,含水量4.23%,反应时间5 h。在此条件下,月桂酸单甘油酯产率的预测值和实验值分别为81.68%和81.32%,说明二次多项回归模型具有良好的预测性。     

响应面分析法优化乳化石蜡制备工艺

采用响应面分析法(RSM)中CCD数学模型优化工艺参数,考察乳化剂用量、乳化时间、乳化温度、搅拌速度各因素之间相互作用对石蜡乳液稳定性的影响。得到乳化石蜡制备的最佳工艺条件:Tween80质量为复合乳化剂质量的32.7%,乳化剂用量为总乳液质量的7.056%,乳化时间为46 min,搅拌速率为1 240 r/min,在此条件下,实验制备得到平均粒径为0.286μm,分散性为0.224的石蜡乳液。结果表明:该模型综合分数预测值为0.656,与实验验证值0.638的相关系数为0.973 2,可用于实际预测。     

响应曲面法优化硫酸铵微波干燥工艺

对微波干燥硫酸铵的新工艺进行研究,探讨了干燥温度、微波干燥时间、物料质量、物料厚度等因素对硫酸铵相对脱水率的影响.并在单因素实验的基础上,以硫酸铵的相对脱水率为响应值采用响应曲面中心组合设计,对硫酸铵的微波干燥工艺参数进行了优化.所获得的优化实验条件:干燥温度86.05℃,微波干燥时间190.50 s,物料质量102....     

Development of polymer derived carbon coated monolith for liquid adsorption application by response surface methodology

The preparation of polymer derived activated carbon coated monolith is reported. The response surface methodology based on Box–Behnken design is used to find the optimal condition for synthesis of mesoporous carbon. The dominant parameters identified are the carbonization temperature, concentration, and molecular weight of pore former agent. Typical values for BET surface area are 341 m²/g _carbon and 20 m²/g _{supported carbon} with pores size distribution in the range of 4–400 nm. The highest pore volume obtained is 182.77 mm³/g _{supported carbon}.     

响应面法优化酶催化酯交换反应研究

为了利用植物油生产可再生的绿色能源——生物柴油,文章利用Novo435固定化脂肪酶,在无有机溶剂存在下催化菜籽油与甲醇酯交换合成生物柴油。利用响应面实验设计和分析方法对菜籽油的酯交换反应条件进行优化,得到了最佳工艺条件:醇油摩尔比1.5∶1,反应温度52℃,搅拌转速200 r/min,脂肪酶与油脂的质量比为10%,反应时间10 h,在此工艺条件下油脂的酯交换率达到48%(理论为50%)。理论甲醇量分3批加入,反应36 h后菜籽油的总酯交换率达到95%(理论酯交换率为100%)。每批试验后利用有机溶剂对脂肪酶进行清洗,然后继续反应,连续使用10个批次,油脂的酯交换率基本未变。     

Studies on biodegradation of phenol using response surface methodology

Biodegradation of phenol was studied using Pseudomonas pictorum (NCIM 2077) immobilized on alginate and activated carbon – alginate beads. Control experiments were also performed using free cells and non‐inoculated activated carbon – alginate beads. The entrapped alginate and activated carbon – alginate beads suffer from a concentration gradient for oxygen in the interior of the beads and hence free cells showed better degradation at lower concentrations of phenol. The results on entrapped alginate beads were modeled using response surface methodology which determines the dependency of the maximum percentage of phenol degraded as a function of the independent variables, namely initial phenol concentration, initial pH, temperature, and diameter of the immobilized beads. The predicted values are in close agreement with the experimental values with the coefficient of correlation equal to 0.9999 and 0.9993 for both P pictorum – alginate beads and activated carbon – P pictorum – alginate beads respectively. © 2002 Society of Chemical Industry     

响应面法优化苦参碱粗品的结晶纯化过程

通过Box-Behnken试验设计,系统地考察了料液比、温度及结晶时间3个因素对苦参碱结晶收率的影响,并运用响应面法对建立的二次回归模型进行了综合分析。结果表明,当料液比为1∶28.78、温度为59.19℃、时间为30min时,苦参碱的结晶收率最大,其值为97.16%。     

Preparation and evaluation of self-healing microcapsules for asphalt based on response surface optimization

The purpose of this study is to explore the best preparation process of asphalt self-healing microcapsules. Response surface design and single factor design were used to optimize the preparation process parameters of asphalt self-healing microcapsules, and the prediction model of core content was established. The optimal preparation process was determined. The results of response surface design showed that the interaction among emulsifier concentration/reaction temperature, core-shell ratio/reaction temperature, and pH/reaction temperature had significant effect on the core content of microcapsules; the microcapsules prepared by the optimal process were spherical with an average particle size of 90.19 μm. The results of thermogravimetric analysis (TGA) and heating simulation test showed that the microcapsule can delay the damage of the core in high temperature environment; the results of nanoindentation test showed that the young's modulus and hardness of the microcapsules were about 2.50 and 0.28 GPa, respectively. Finally, the improvement mechanism of self-healing performance of asphalt by microcapsules was revealed by fluorescence microscope.     

响应面法优化以重组大肠杆菌发酵生产类人胶原蛋白过程

In order to improve the production of human-like collagen Ⅲ (HLC Ⅲ) by fed-batch culture of recom-binant Escherichia coli BL21, the Plackett-Burman and Box-Behnken design were applied to optimize the fermen-tation process parameters.Three variables (induction time, inoculum age and pH), which have significant effects on HLC Ⅲ production, were selected from eight variables by Plackett-Burman design.With the regression coefficient analysis in the Box-Behnken design, a relationship between HLC Ⅲ production and three significant factors was obtained, and the optimum levels of the three variables were as follows: induction time 3.2h, inoculum age 12.6 h and pH 6.7.The 3D response surface plots and 2D contour plots created by the Box-Behnken design showed that the interaction between induction time and pH and that between innoculum age and pH were significant.An aver-age 9.68 g·L~(-1)HLC Ⅲ production was attained in the validation experiment under optimized condition, which was 80% higher than the yield of 5.36 g·L~(-1) before optimization.     

响应面法优化微生物诱导碳酸钙沉积培养基

通过响应面法对微生物诱导CaCO3沉积的培养基组分进行优化。结果表明,最适宜培养基配方为葡萄糖30g/L、大豆蛋白胨10g/L、尿素50g/L、硝酸钙0.5mol/L、吐温80体积分数0.05%以及氯化镍250μmol/L。葡萄糖浓度和尿素浓度、葡萄糖浓度和硝酸钙浓度、葡萄糖浓度和吐温浓度、硝酸钙浓度和吐温浓度以及尿素浓度和氯化镍浓度,对微生物诱导CaCO3沉淀量的影响有着比较显著的双因子效应。沉淀物CaCO3含有少量有机质,形成方解石型或方解石和球霰石混合晶型的CaCO3,其形貌和堆积密度随外界条件改变而不同。     

Dynamic response surface methodology using Lasso regression for organic pharmaceutical synthesis

To study the dynamic behavior of a process,time-resolved data are collected at different time instants during each of a series of experiments,which are usually designed with the design of experiments or the design of dynamic experiments methodologies.For utilizing such time-resolved data to model the dynamic behavior,dynamic response surface methodology(DRSM),a datadriven modeling method,has been proposed.Two approaches can be adopted in the estimation of the model parameters:stepwise regression,used in several of previous publications,and Lasso regression,which is newly incorporated in this paper for the estimation of DRSM models.Here,we show that both approaches yield similarly accurate models,while the computational time of Lasso is on average two magnitude smaller.Two case studies are performed to show the advantages of the proposed method.In the first case study,where the concentrations of different species are modeled directly,DRSM method provides more accurate models compared to the models in the literature.The second case study,where the reaction extents are modeled instead of the species concentrations,illustrates the versatility of the DRSM methodology.Therefore,DRSM with Lasso regression can provide faster and more accurate datadriven models for a variety of organic synthesis datasets.     

Optimizing nanoencapsulation of Heracleum lasiopetalum by response surface methodology

This study was carried out to optimize formulation for Heracleum lasiopetalum (golpar) extract nanoencapsulation by response surface methodology (RSM). The primary water-in-oil emulsion was fabricated by (5%–10%) golpar extract (GE), (40%–35%) emulsifier span 80 (EM), and (50%–60%) sunflower oil (SO). The coating materials were the mixture of Lepidium sativum seed gum (LSG) and whey protein concentrate (WPC) at different ratios (1:0, 1:1, and 0:1). The yield of nanoencapsulation of GE, particle size, and zeta potential was investigated as responses of RSM. The optimal formulation for water-in-oil-in-water emulsion of GE were SO: 50.46%, GE 9.52%, and EM: 36.30% in LSG, SO: 57.07%, GE: 7.12%, and EM: 30.85% in LSG:WPC, and SO: 54.98%, GE: 9.05%, and EM: 39.87% in WPC coating. In conclusion, the nanoencapsulation of GE prepared with the optimized formulation by RSM ensures the gradual release and higher stability to sedimentation during storage with nanometric size and high yield of encapsulation. The nanocapsules of GE can be used as a natural antioxidant in food systems.     

An online acquisition method for monitoring the surface growth of flame retardant protective layers

This paper describes the development of a video acquisition system aimed at monitoring the surface growth of flame‐retarded polymers during flammability and combustion tests. The system minimizes the disturbances of the flames on the image sensors, thus gathering a video of the material surface. The device continuously records and quantitatively measures the carbonization front growth rate. The apparatus consists of a camera with customized lighting and dedicated software acquiring images of the burning specimen. The UL94 test procedure has been used during the development of the device and as test bed for the apparatus. Copyright © 2015 John Wiley & Sons, Ltd.     

响应面法优化达托霉素发酵培养基

采用响应面法对玫瑰孢链霉菌发酵产达托霉素的培养基进行了优化。首先通过Placket-Burman设计法筛选出影响达托霉素产量的4个重要因素:初始pH值、葡萄糖、L-天冬氨酸(L-Asp)、硫酸钾。其中初始pH值的影响极为显著(p<0.01),因此,对初始pH值进行了单因素试验,得到最优初始pH值为8.6。在此基础上对其余3个因素用最陡爬坡路径逼近最大响应区域后,利用响应面中心组合设计对显著因素进行优化,得到最适培养基组成为:葡萄糖13.0 g/L、L-Asp 2.6 g/L、硫酸钾4.1 g/L。在此优化条件下,达托霉素产量达373.98 mg/L,与预测值(365.76 mg/L)非常接近,比优化前产量提高了2.25倍。     

基于响应面模型的注塑件精密成型工艺优化

为了提高注塑件品质,对注塑件进行了成型工艺优化.结合中心复合试验设计,采用Moldflow软件和响应面模型方法,拟合得到注塑件二阶响应面模型,由响应面模型获得成型最佳产品品质的工艺参数组合.采用Moldflow软件对该工艺参数组合进行了分析.结果表明:采用响应面模型预测与Moldflow软件分析得到的体积收缩率相差约0...     

Influence of surface morphology on oxide growth in porous alumina

The formation of aluminium oxide layers on surfaces with different morphologies prepared by various structuring methods has been analyzed. Different growth rates and thus different oxide thicknesses have been observed under the same reaction parameters on planar surfaces in contrast to convex and concave surfaces with different radii in the curvature. The stronger the curvature of the concave or convex surface, the more the growth rates differ from the growth rates on planar surfaces. The influence of the electrical field strength on those differences is discussed in a simple model.     

响应面法优化咪唑啉硫酸酯盐的合成及性能研究

以氨基磺酸为硫酸化试剂,月桂酸和羟乙基乙二胺为原料,尿素为催化剂,合成了咪唑啉硫酸酯盐。利用IR和1H NMR对合成产物的结构进行了表征。在单因素试验的基础上,利用响应面法优化硫酸酯盐的合成工艺条件,确定较佳工艺条件为:反应温度107℃、反应时间3.7 h、n(咪唑啉)∶n(氨基磺酸)=1∶1.09、催化剂用量为反应物总质量的2.93%,在此条件下咪唑啉硫酸酯盐的产率为75.20%。同时测定了咪唑啉硫酸酯盐的表面活性及泡沫性能,测试结果表明,合成的咪唑啉硫酸酯盐具有良好的表面活性和泡沫性能。     

响应曲面法漂白紫胶微波-真空干燥工艺研究

为提高漂白紫胶产品质量及生产效率,采用微波-真空干燥漂白紫胶研究了不同压强、微波功率和干燥时间对漂白紫胶产品颜色指数和含水率的影响,用响应曲面法（RSM）设计试验并建立了该工艺条件的拟合方程。结果表明,拟合方程的拟合度较高,所建立的数学模型可以用于描述漂白紫胶的微波-真空干燥。漂白紫胶微波-真空干燥的最优条件：干燥压强为3.0 kPa,微波功率为795 W,干燥时间为30 min。在优化条件下进行了验证实验,得到了颜色指数为0.9、含水率为0.028 9kg水/kg干料的产品。