响应面法优化纳豆激酶液体发酵条件的研究

为了提高纳豆激酶的酶活力,本研究借助Minitab软件,采用Plackett-Burman试验设计方法和响应面分析方法对保存的枯草芽孢杆菌纳豆亚种（Bacillus subtlis natto。简称纳豆菌）-NT207进行了液体发酵条件的优化。首先通过Plackett-Burman方法对11个相关影响因素的效应进行评价,并筛选出有显著正效应的木糖浓度和有显著负效应的接种量、K2HP04浓度等三个因素,然后利用响应面分析方法确定了上述三个因素的最佳工艺参数。实验结果表明,在优化后的发酵条件下,纳豆激酶的产量为1504．51U／mL,比优化前提高了130．3％。     

响应面法优化兰香草总黄酮超声提取工艺

采用NaNO2-Al(NO3)3-NaOH体系分光光度法,测定吸光度,比较不同条件下兰香草总黄酮提取率;在单因素试验的基础上利用响应面法对提取工艺进行优化设计;通过Plackett-Burman软件对试验因素进行筛选;应用Design Expert 7.0软件对试验因素进行中心组合设计,并将实验结果进行回归分析。结果表明,乙醇浓度、液料比、提取时间为影响兰香草总黄酮提取率的主要因素;试验所得模型与试验数据拟合度较高,可用来预测不同提取条件下的兰香草总黄酮得率;由回归方程求得的最佳提取工艺为在40℃温度下,用73%乙醇为溶剂,控制液料比为45 mL·g-1,提取32 min。     

大学男子排球队员弹跳力训练模型的建立及优化

实施“健康中国行动”,翻开学校体育新篇章，促进良好的健身氛围，促进学生坚持运动，养成终身体育意识.大学排球队的成立能够为学生建立一个良好的健身平台，为学生良好的心理素质培养以及提高团队合作精神有强有力的支持.弹跳力是排球运动必不可少的一项身体素质，为了提高弹跳素质，探究弹跳力训练模型，掌握弹跳力有效训练手段之间的关系，本研究选取安徽财经大学、蚌埠学院男子排球队36名大一新生为研究对象，采用Plackett-Burman设计(Plackett-Burman Design, P-B)对训练弹跳力的相关因素进行分析.拟通过Plackett-Burman设计(P-B)筛选出与弹跳力有关的因子，并通过响应曲面法(RSM)进行关联多变量分析，重点探究弹跳力训练3个关键影响因素的最佳水平范围，以此制定最佳模型，为实施量化弹跳训练，及时调控纠偏提供了数据参考.     

新课程理念下的作业设计

新课程实施以来,许多教师存在着一个比较普遍的困惑,就是如何设计能够体现新课程理念的作业,也就是说,什么样的作业能符合新课程要求,如何以新课程标准为依据,从知识与技能、过程与方法、情感态度和价值观的三维目标上设计作业。因而,探讨新课程理念下的作业设计迫在眉睫,它关系到课程改革的成败和学生良好学习习惯的养成。     

基于Matlab仿真的数据降维实验设计

在Matlab的基础上,以3种经典的数据降维方法——主成分分析(PCA)、线性判别分析(LDA)和保局投影算法(LPP)为例,给出3种降维方法的最优化比较结果,对数据降维实验方法进行了探讨和设计。通过UCI标准数据集和ORL、Yale人脸数据集的比较实验表明:3种降维方法均能较好地完成降维任务,其中LPP和LDA数据降维方法效率较优,但在不同的实验条件下,表现略有不同。     

基于课程标准教学设计开发的过程与案例

主持絮语 基于标准的教学设计最关键的环节是将具体的设计方法和策略应用于教学实践中。为了帮助教师在教学准备过程中理解课程标准,贯彻课程标准的理念和要求,实现课程标准与教学实施的一致性。2013年10月至12月,河南省郑州市教研室组织教研员和一线优秀教师开展了“基于标准教学设计”的研修,各研修小组从“案例比较”“方法研讨”“完成设计”“实施反思”四个阶段开展了基于标准的教学设计活动。     

从一堂课谈教学方法的优化选择

本文在教学法理论指导下,通过多年教学实践比较,具体设计了《椭圆及其标准方程》这一堂概念课的教学过程,提出了要实现课堂教学目的,优化选择教学方法的重要性。     

基于IRT的共同题非等组设计中五种项目参数等值方法的比较研究

本文采用共同题非等组设计,对五种基于IRT的项目参数等值方法进行比较研究。研究数据来自湖北某试点地区课改实验区和非课改区考生在标准化中考数学科目的考试数据,兼用大样本标准和其他标准作为各等值方法比较的检验标准,以RMSD指标作为操作性检验标准,利用STUIRT程序进行等值分析。研究结果表明,针对本研究所设置的等值情境,MS方法稳健性最差,对于项目难度参数的等值,同时校准方法最好,其次是SL特征曲线法,对于项目区分度参数的等值,MM方法精确性最好。     

教师职业专业化视角下教师职业标准的构建

教师职业标准应该以教师的服务理念为基点设计具体的道德标准。在当前由于商业文化盛行而导致教师职业道德滑坡的背景下,将服务精神确立为我国建构教师职业标准中的道德标准的基点更有现实意义。     

“结构化视角”下的小学数学作业设计探究

在“结构化视角”下进行小学数学作业设计,是为了引导学生更好地掌握数学知识,形成结构化的知识。文章从新课程标准提出的作业设计要求、结构化视角下对作业设计的方式方法、结构化视角下的作业设计等角度出发进行了探究,主张作业设计要体现学习方法的结构化、知识过程的结构化、学生特点的结构化、知识融合的结构化,提倡学生探究能力的培养。     

两种益生菌混合发酵乳清培养基的优化

根据嗜酸乳杆菌和双歧杆菌的营养需要和生长特性,采用响应面分析法对其混合发酵乳清培养基进行优化研究。利用SAS中的Plackett-Burman二水平设计法成功选取了对嗜酸乳杆菌和双歧杆菌发酵培养影响显著的3个因素(大豆分离蛋白、西红柿汁和胡萝卜汁),再用最陡爬坡实验法确定因素水平,最后依据回归模型分析,得出最佳的混合发酵乳清培养基配方为:4%乳清粉、1.4%大豆分离蛋白、10%西红柿汁、13%胡萝卜汁、0.5%半胱氨酸盐酸盐、0.04%低聚异麦芽糖、0.3%K2HPO4。用此优化的培养基培养嗜酸乳杆菌和双歧杆菌,活菌数可高达9.8×109 cfu.mL-1。     

Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue （MIL-C） by Streptoverticillium rimofaciens ZJU 5119

Cytosine-substituted mildiomycin analogue (MIL-C) was produced effectively by supplementing cytosine into the culture of Streptoverticillium rimofaciens. In order to improve the yield of MIL-C, statistically-based experimental designs were applied to optimize the fermentation medium for S. rimofaciens ZJU 5119. Fifteen culture conditions were examined for their significances on MIL-C production using Plackett-Burrnan design. The Plackett-Burman design and one-variable-at-a-time design indicated that glucose and rice meal as the complex carbon sources, and peanut cake meal and NH4NO3 as the complex nitrogen sources were beneficial for MIL-C production in S. rimofaciens ZJU 5119. The results of further central composition design (CCD)showed that the optimal concentration of glucose, rice meal and peanut cake meal were 18.7 g/L, 64.8 g/L and 65.1 g/L,respectively. By using this optimal fermentation medium, the MIL-C concentration was increased up to 1336.5 mg/L, an approximate 3.8-fold improvement over the previous concentration (350.0 mg/L) with un-optimized medium. This work will be very helpful to the large-scale production of MIL-C in the future.     

基于主成分分析的乳酸链球菌素发酵条件优化

本研究以乳酸链球茵（1actococcuslactis）为究对象,在单因素基础上进行PB试验设计,对影响Nisin代谢产量的发酵培养基配方中的14个因素进行降维处理,以抑茵圈直径作为主要评价指标,优选出与Nisin代谢产量关系最为密切的三个因素,分别为发酵温度、KCl的添加量及葡萄糖添加量．     

机械力化学技术制备磷酸法活性炭及其碘吸附性能的研究

研究采用机械力化学技术制备了吸附性能良好的活性炭。试验采用Plackett—Burman（PB）实验设计和Box—BehnkenDesign（BBD）设计法对影响活性炭碘吸附值的6个条件进行筛选优化。PB实验设计与统计学分析表明酸屑比、研磨时间、活化温度、磷酸浓度是影响活性炭碘吸附值的四个关键因素。以碘吸附值为响应目标,对四因素进行BBD设计,并经响应面法优化分析得到影响活性炭碘吸附值的二阶模型,确定了机械力化学技术制备磷酸活性炭的较优操作条件为：酸屑比2．00,研磨时间22min,活化温度406℃,磷酸浓度20％,活性炭的碘吸附值达1195．23mg／g。     

Optimization of fermentation conditions for P450 BM-3 monooxygenase production by hybrid design methodology

INTRODUCTION P450 enzymes are found throughout nature and can catalyze the oxidation of various chemicals (Ortiz de Montellano, 1995). Because of their important roles in these processes, numerous systems have been developed for the expression of P450s in vitro (Helvig and Capdevila, 2000; Nakamura et al., 2001; Deeni, 2001). But P450 enzymes fermentation levels in the microbial system are too low to catalyze the reactions for industrial preparations. Therefore, it is necessary to impr…     

Rapid quantification of multi-components in alcohol precipitation liquid of <Emphasis Type="Italic">Codonopsis Radix</Emphasis> using near infrared spectroscopy (NIRS)

A near infrared spectroscopy (NIRS) approach was established for quality control of the alcohol precipitation liquid in the manufacture of Codonopsis Radix. By applying NIRS with multivariate analysis, it was possible to build variation into the calibration sample set, and the Plackett-Burman design, Box-Behnken design, and a concentrating-diluting method were used to obtain the sample set covered with sufficient fluctuation of process parameters and extended concentration information. NIR data were calibrated to predict the four quality indicators using partial least squares regression (PLSR). In the four calibration models, the root mean squares errors of prediction (RMSEPs) were 1.22 μg/ml, 10.5 μg/ml, 1.43 μg/ml, and 0.433% for lobetyolin, total flavonoids, pigments, and total solid contents, respectively. The results indicated that multi-components quantification of the alcohol precipitation liquid of Codonopsis Radix could be achieved with an NIRS-based method, which offers a useful tool for real-time release testing (RTRT) of intermediates in the manufacture of Codonopsis Radix.     

Application of response surface methodology in medium optimization for pyruvic acid production of <Emphasis Type="Italic">Torulopsis glabrata</Emphasis> TP19 in batch fermentation

Response surface methodology （RSM） was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows： ammonium sulfate 0.7498 （10.75 g/L）, glucose 0.9383 （109.38 g/L） and nicotinic acid 0.3633 （7.86 mg/L） with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient （R^2） was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results.     

Statistical culture-based strategies to enhance chlamydospore production by <Emphasis Type="Italic">Trichoderma harzianum</Emphasis> SH2303 in liquid fermentation

Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant pathogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a lack of optimal liquid fermentation technology. In this study, we explored response surface methodologies for optimizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, identified cornmeal, glycerol, and initial pH levels as the most significant factors (P<0.05) for enhancing the production of chlamydospores. Subsequently, we applied the Box-Behnken design to study the interactions between, and optimal levels of, a number of factors in chlamydospore production. These statistically predicted results indicated that the highest number of chlamydospores (3.6×10⁸ spores/ml) would be obtained under the following condition: corn flour 62.86 g/L, glycerol 7.54 ml/L, pH 4.17, and 6-d incubation in liquid fermentation. We validated these predicted values via three repeated experiments using the optimal culture and achieved maximum chlamydospores of 4.5×10⁸ spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianum SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents.