鲭鱼酶解工艺双响应面法优化及抗氧化活性研究

采用双响应面法优化超声波辅助酶解鲭鱼蛋白,制备鲭鱼多肽,探究其抗氧化活性.以酶解液对DPPH自由基和ABTS自由基的清除率为指标,获得最适蛋白酶并双响应面优化酶解工艺条件,探究其抗氧化活性.结果表明:木瓜蛋白酶为最佳水解酶,最优酶解工艺为pH 6.0、超声时间40 min、温度53℃、料液比1∶3(g/mL)、酶添加量3 000 U/g、酶解时间2 h,所得的酶解液DPPH自由基清除率为91.21%,ABTS自由基清除率为84.12%;鲭鱼多肽具有较好的抗氧化活性,ABTS自由基和DPPH自由基半抑制率IC50分别为32.75μg/mL、1.20 mg/mL.该研究结果可为鲭鱼抗氧化肽的大量制备提供工艺参考,为鲭鱼抗氧化多肽在食品工业中的应用研发提供了理论基础.

基于双响应面法的行星齿轮机构稳健设计研究

双响应面法是通过试验设计分别构造响应面均值和方差的近似模型,并通过该模型进行优化的一种稳健设计方法。文中对双响应面法中的实验设计、响应面模型的建立等内容进行了分析研究,并将此方法应用于行星齿轮机构设计中,建立了基于中心组合试验的行星齿轮机构稳健设计模型。与传统优化方法相比,该方法提高了设计的稳健性。

基于双响应面法和BBD的车辆悬架系统稳健设计

选用某种型号车辆的麦弗逊悬架系统,探讨悬架系统设计中同时考虑车辆的操纵稳定性和乘客的乘座舒适性问题,运用ADAMS软件对麦弗逊悬架进行建模并对其进行空间运动学定义。将悬架系统的结构尺寸视为可控因素,刚度和阻尼为不确定因素。通过对该悬架的一系列跳动分析和试验仿真得出对悬架的跳动特性影响较大的关键点,运用box-behnken design(BBD)试验方法安排试验,采用稳健设计中的双响应面法对车辆悬架系统进行稳健性分析。为车辆悬架系统的研究提供了一种新的方法。

基于双响应面法的公差设计研究

探讨了产品综合成本的构成 ,以此为基础提出了以产品综合成本最低为目标的公差稳健设计模型 ,并利用双响应面法 (ResponseSurfaceMethodology ,RSM )来实现公差的稳健优化设计。

响应面法优化油茶果壳纤维素的提取工艺研究

目的:本文以油茶果壳为原料,得到油茶果壳纤维素提取的最佳工艺条件,为油茶果壳综合开发提供理论依据及数据参考。方法:采用碱液预处理,再用一定比例的硝酸-乙醇溶液处理,在单因素实验的基础上,通过响应面法设计实验优化纤维素提取的工艺条件。结果:油茶果壳纤维素提取的优化工艺的条件为温度为81℃,固液比为1︰12,处理时间为93 min,所得产品纤维素提取率最高,此时油茶果壳纤维素含量为(32.79±0.12)%。结论:方差分析结果表明,所选模型具有显著性(p<0.05),相关系数R^(2)=0.9282,验证试验纤维素的提取率为(32.79±0.12)%,与预测值32.91%的误差仅为0.36%,证明所得模型可信,优化工艺参数切实可行,红外光谱(FTIR)表征了提取的油茶壳纤维素的结构,表征结果表明提取的油茶果壳纤维素与纤维素标准物结构基本一致。

基于双响应面法的螺旋弹簧设计

为了减小制造误差对螺旋弹簧稳健性能的影响,采用双响应面法对其进行了稳健设计研究。以最小特性优化策略为目标,同时建立弹簧质量均值和方差的双响应面设计模型。经过正交试验得出,对弹簧质量均值影响因素的排序是钢丝直径、弹簧中径、弹簧圈数,对弹簧质量方差影响因素的排序是弹簧中径、钢丝直径、弹簧圈数;各因素与其对应响应面均成线性关系;在制造过程中要保证主要影响因素(钢丝直径、弹簧中径)的精度,可以适当放宽次要影响因素(弹簧圈数)的精度。当存在不确定因素的影响,这种方法既保证了目标趋于最优,又保证了较小的偏差,提高了螺旋弹簧的稳健性能。

响应面法优化豆乳稳定剂配方研究

本文采用响应面分析法研究刺槐豆胶、瓜尔豆胶和黄原胶对豆乳的稳定性影响,确定其最佳水平,结果表明:刺槐豆胶用量0.06‰、瓜尔豆胶用量0.11‰和黄原胶用量0.19‰组成的复合稳定剂制得的豆乳稳定性较好。

稳健性设计的双响应面法

提出一种替代静态田口方法进行稳健性设计的方法──双响应面法。这种方法不使用田口方法中的信噪比和二步优化概念，而是直接将质量特性的均值和标准差拟会为响应曲面，然后化为约束最小问题，并用序列线性规划求解。数值算例说明该方法的有效性。

响应面优化冷榨花生粕酶法制备多肽工艺的研究

运用了Min Run Equirelicated Res IV析因设计、爬陡坡试验以及中心复合响应面设计对碱性蛋白酶酶解冷榨花生粕蛋白制备活性多肽工艺进行了优化。析因设计结果和显著性分析发现,[E]和[S]为最重要因素(P<0.01),酶解pH和酶解时间为重要因素(P<0.05)。在析因设计、爬陡坡试验设计结果基础上应用中心复合响应面设计对[E](X1)、[S](X2)和酶解时间(X3)进行了响应面优化分析。响应面优化结果表明,在[E]=4 300 U/g[S],[S]=10.0%,酶解时间为85 min最优条件下,酶解液多肽含量达到最高,为(0.209±0.005)%(n=6),与模型预测值0.207 8%接近,偏差为5.77%。试验表明,酶促水解是制备活性多肽的有效方法。

不同生长期走马胎 总黄酮含量及抗氧化活性比较研究

本研究为优化走马胎总黄酮超声提取工艺,探究不同生长期走马胎总黄酮含量及抗氧化活性的差异。通过单因素试验考察温度、乙醇浓度、料液比、提取时间对总黄酮提取的率的影响,采用Box-Behnken响应面法优化提取工艺。使用最佳提取工艺提取不同生长期走马胎不同部位黄酮,比较含量和抗氧化活性。结果表明,走马胎黄酮最佳提取工艺为温度48.88℃、乙醇浓度58.62%、料液比1:49.86g/mL提取时间49.04min:根、茎、叶黄酮含量最高的生长期分别为4年、1年、1年:走马胎总黄酮对DPPH、-OH有较好的清除能力且总还原力较好。该文研究不同生长期走马胎总黄酮含量及抗氧化活性,为走马胎植株的大规模种植及采收提供参考,以及其体内黄酮类化合物开发利用和工业化使用提供理论依据,更为后续紫金牛属药用植物的资源化应用奠定基础。

表面活性剂辅助超声提取柿叶总黄酮工艺优化

目的:优选表面活性剂辅助超声提取柿叶总黄酮工艺。方法:以柿叶为材料,总黄酮得率和DPPH自由基清除率为指标,分别考察表面活性剂种类、表面活性剂质量分数、液料比、超声时间及超声温度对指标的影响,并通过Box-Behnken设计-双响应面法优选总黄酮提取工艺。结果:最佳提取工艺:乙醇体积分数70%、十二烷基硫酸钠质量分数0.6%、液料比22:1 mL/g、超声温度30℃和超声时间7.3 min,此时柿叶总黄酮得率的实际值为(103.63±0.10)mg/g,DPPH自由基清除率为(65.35%±0.12%)。结论:优化后的提取工艺可有效地提高柿叶总黄酮得率,为柿叶黄酮类成分资源的研究开发与利用提供一定的理论基础。

Response surface optimization of process parameters for reduction roasting of low-grade pyrolusite by bagasse

The reduction roasting processes for low-grade pyrolusite using bagasse as the reducing agent was statistically analyzed. The central composite rotatable design （CCD） was used to optimize this reduction roasting processes. The three process parameters studied were the mass ratio of bagasse to ore, the roasting temperature and the roasting time. Analysis of variance （ANOVA） was used to analyze the experimental results. The interactions between the process parameters were done by using the linear and quadratic model. The results revealed that the linear and quadratic effects as well as the interaction are statistically significant for the mass ratio and roasting temperature but insignificant for the roasting time. The optimal conditions of 0.9：10 of mass ratio, the roasting temperature of 450 ~C, the roasting time of 30 min were obtained. Under these conditions, the predicted leaching recovery rate for manganese was 98.1%. And the satisfied experimental result of 98.2% confirmed the validity of the model.

Optimization of preparing V_2O_5 by calcination from ammonium metavanadate using response surface methodology

Parameters of technique to prepare vanadium pentoxide by calcination from ammonium metavanadate were optimized using central composite design of response surface methodology. A quadratic equation model for decomposition rate was built and effects of main factors and their corresponding relationships were obtained. The results of the statistical analysis show that the decomposition rate of ammonium metavanadate is significantly affected by calcination temperature and calcination time. The optimized calcination conditions are as follows： calcination temperature 669.71 K, calcination time 35.9 min and sample mass 4.25 g. The decomposition rate of ammonium metavanadate is 99.71%,which coincides well with experimental value of 99.27% under the optimized conditions, suggesting that regressive equation fits the decomposition rates perfectly. XRD reveals that it is feasible to prepare the V2O5 by calcination from ammonium metavanadate using response surface methodology.

Reliability analysis of piles constructed on slopes under laterally loading

Response surface method is used to study the reliability analysis of laterally loaded piles in sloping ground. A development load-displacement （p-y） curve for laterally loaded pile response in sloping ground is used to model the pile-soil system, both the pile head displacement and the maximum bending moment of the piles are used as the performance criteria in this study. The reliability analysis method of the laterally loaded pile in sloping ground under the pile head displacement and the maximum bending moment failure modes is proposed, which is in good agreement with the Monte Carlo method. The influences on the probability index of failure by a number of parameters are discussed. It is shown that the variability of pile head displacement increases with the increase in the coefficients of variation of ultimate bearing capacity factor （Npu）, secant elastic modulus at 50%（E50） and level load （H）. A negative correlation between Npu and non-dimensional factor （λ） leads to less spread out probability density function （PDF） of the pile head displacement;in contrast, a positive correlation between Npu andλgives a great variation in the PDF of pile head displacement. As for bearing capacity factor on ground surface （Npo） and λ, both negative and positive correlations between them give a great variation in the PDF of pile head displacement, and a negative correlation will obviously increase the variability of the response.

Identification of processing window for extrusion of large thick-walled Inconel 625 alloy pipes using response surface methodology

Identifying suitable processing window is necessary but difficult for achieving favorable microstructure and performance in extrusion of large thick-walled pipe with difficult-to-deform Inconel 625 alloy. In this work, a method was established for identifying the extrusion process window considering temperature control using response surface methodology. Firstly, the response surface models, which correlate temperature rise and peak temperature to key extrusion parameters, have been developed by orthogonal regression based on finite element calculated data. Secondly, the coupled effects of the key extrusion parameters on the temperature rise and peak temperature have been disclosed based on the regression models. Lastly, suitable extrusion processing windows, which are described by contour map of peak temperature in the space of extrusion speed and initial billet temperature, have been established for different extrusion ratios. Using the identified process window, a suitable combination of the key extrusion parameters can be determined conveniently and quickly.

Research on the Extraction Process of Pu-erh Tea Polysaccharide by Response Surface Analysis

[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including extraction temperature, ex- traction duration and solid-liquid ratio, on the extraction yield of tea polysaccharide. Box-Behnken central composite design and response surface methodology were adopted to determine the optimal extraction process of Pu-erh tea polysaccharide. [Result] The results of response surface analysis showed that the optimal extraction process was solid-liquid ratio of 1：17, extraction temperature of 80 ℃ and extraction duration of 78.5 min, and the Pu-erh tea polysaccharide yield was 12.72%. [Conclu- sion] Using response surface methodology （RSM） is feasible for the optimization of Pu-erh tea polysaccharide extraction process, and the tea polysaccharide yield increased significantly.

INTEGRATION SHAPE AND SIZING OPTIMIZATION OF COMPOSITE WING STRUCTURE BASED ON RESPONSE SURFACE METHOD

An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method （QRSM）. The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting.

Response surface optimization of process parameters for removal of F and Cl from zinc oxide fume by microwave roasting

Microwave was applied to roasting the zinc oxide fume obtained from fuming furnace for the removal of F and Cl. The effects of important parameters, such as roasting temperature, holding time and stirring speed, were investigated and the process conditions were optimized using response surface methodology (RSM). The results show that the effects of roasting temperature and holding time on the removal rate of F and Cl are the most significant, and the effect of stirring speed is the second. The defluorination rate reaches 92.6% while the dechlorination rate reaches 90.2%, under the process conditions of roasting temperature of 700 °C, holding time of 80 min and stirring speed of 120 r/min. The results indicate that the removal of F and Cl from fuming furnace production of zinc oxide fumes using microwave roasting process is feasible and reliable.

Study on the Removal of Carbendazim Residues by Combination of Ca(ClO)_2 and O_3

[Objective] The research aimed to investigate the influences of each factor in the combination of Ca（ClO）2 and O3 on removing carbendazim residues from kumquat. [Method] By using Box-Behnken response surface methodology （RSM）, the effects of initial concentration of carbendazim, soaked time of Ca（ClO）2 solution, soaked time of ozone water and Ca（ClO）2 concentration on removing carbendazim residues from kumquat were studied. [Result] In the test range, the effects of each factor on removing carbendazim residues from kumquat were soaked time of ozone water, soaked time of Ca（ClO）2 solution, initial residual amount of carbendazim and concentration of Ca（ClO）2 solution in turn. By fitting the experimental result, the quadratic polynomial model of relationship between residual amount of carbendazim and the above each factor was obtained. The verified experimental result showed that the model had high precision. [Conclusion] The model could be used to guide using the appropriate soaked time of Ca（ClO）2 solution, soaked time of ozone water and Ca（ClO）2 concentration under the certain initial concentration and residue limits of carbendazim, which guaranteed obtaining the expected residue limits of carbendazim.

Optimization of Supercritical Carbon dioxide Extraction of Ginger Essential Oil by Response Surface Method

[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.