Bacillus subtilis SPB1 biosurfactant: Production optimization and insecticidal activity against the carob moth Ectomyelois ceratoniae

Bacillus subtilis SPB1 was shown to produce a lipopeptide biosurfactant. The insecticidal activity of this biosurfactant was evaluated against Ectomyelois ceratoniae Zeller, a moth pest of stored dates in Tunisia. The LC₅₀ and LC₉₀ values after six days of contact were 152 μg/g and 641 μg/g, respectively. To promote an economical production of this highly effective bioinsecticide, statistical experimental designs and response surface methodology were employed to optimize the concentrations of agro-industrial residues and humidity, for lipopeptide biosurfactant production by B. subtilis SPB1 under solid state fermentation. The optimal medium leading to a production yield near to 28 mg of crude lipopeptide preparation per g of wet solid material was composed of a mixture of 4.34 g of tuna fish flour and 5.66 g of potato waste flour with a moisture content of 76%.     

石化污泥脱水工艺优化研究

[目的]确定污泥最佳絮凝剂种类及其最佳的投加量和脱水工艺参数。[方法]针对石化企业污泥脱水工艺中存在的问题，以污泥沉降性能、污泥比阻和滤饼含水率为指标筛选出最佳絮凝剂，并通过正交试验对污泥脱水工艺进行优化。[结果]各因素对滤饼含水率的影响顺序为：搅拌水平〉投加量〉抽滤压力〉絮凝剂。最佳操作条件为絮凝剂K6728投加量2．0ml；搅拌水平150r／min 10s，50r／min 10min：过滤压力0．05MPa。各因素对污泥比阻的影响顺序为：搅拌水平〉抽滤压力〉投加量〉絮凝剂。最佳操作条件为絮凝剂K6728投加量2．5ml；搅拌水平150r／min 10s，50r／min 10min；过滤压力0．03MPa。综合分析得出最佳工艺参数为：K6728絮凝剂投加量2．0ml；搅拌水平150r／min 10s，50r／min 10min；过滤压力0．03MPa。此时，污泥脱水效果最佳。[结论]优化了石化污泥脱水工艺。     

Protein extraction from defatted wheat germ by reverse micelles: Optimization of the forward extraction

In this work, the forward extraction of defatted wheat germ protein (DWGP) by reverse micelles was studied. The reverse micellar systems were formed by sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT), isooctane and KCl solution. The effects of AOT concentration, pH, KCl concentration, extraction time, the amounts of defatted wheat germ flour (DWGF), W₀ (the molar ratio of water to surfactant, i.e. W₀ = [H₂O]/[AOT]) and temperature on the forward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum extraction was achieved by response surface methodology (RSM). The experimental results lead to the conclusion that the highest forward extraction efficiency of DWGP was reached at the AOT concentration 0.06 g/mL, pH 8, KCl concentration 0.1 mol/L, time 30 min, the amounts of DWGF 0.500 g, W₀ 25 and temperature 36 °C. Under these conditions, the forward extraction efficiency of DWGP achieved 37%.     

轴流泵喇叭管的优化水力设计

将喇叭管和开散式进水池内的流场视为一个整体，采用文献[3]介绍的直接求解雷诺平均N-S方程和标准K-ε紊流模型方程组的方法，模拟了进水池和喇叭管内的流动，并在此基础上对喇叭管的形状进行了水力优化计算。     

水地胡麻密肥高产栽培模型研究

在宁夏半干旱地区立地条件下,采用二次正交旋转组合回归设计,研究了种植密度和施肥水平对水地胡麻产量的影响。结果表明,参试的密肥因素对胡麻产量的作用由大到小依次为氮肥施用量、有机肥施用量、播种粒数、磷肥施用量,并通过模拟选优,确定了水地胡麻籽粒产量高于1 950.00 kg/hm2的优化农艺方案。     

森林采伐限额与林业企业生产经营优化的探讨

简述了实施森林采伐限额制度的意义，以及实施限量采伐对林业企业经济的影响。利用投入产出与线性规划最优化模型对林业企业生产经营进行优化设计，提出了解决林业企业民限量采伐矛盾的方法和途径。     

多媒体辅助教学漫谈

本文以语文教学为例,语文多媒体教学既有优点,也有缺点,运用多媒体教学利大于弊.因此如何优化语文多媒体教学,使之扬长避短是语文教师今后要努力做的事.     

记忆指导模拟退火算法的研究

提出了改进模拟退火算法的记忆指导模拟退火算法。该算法能够利用已知信息对搜索过程进行指导，提高算法的搜索效率，该法对回火退火算法的计算量减少５０％。     

分类规则挖掘算法综述

分类规则挖掘是数据挖掘中一个重要的研究领域.通过介绍当前数据挖掘中具有代表性的分类算法,总结了各种算法的优缺点,给出了分类算法的应用以及分类算法面临的挑战,并对分类算法的发展方向进行了展望,为使用者选择算法或研究者改进算法提供了借鉴.     

FSWM: A hybrid fuzzy-stochastic water-management model for agricultural sustainability under uncertainty

A hybrid fuzzy-stochastic water-management (FSWM) model is developed for agricultural sustainability under uncertainty, based on advancement of a multistage fuzzy-stochastic quadratic programming (MFSQP) approach. In MFSQP, uncertainties presented in terms of fuzziness and randomness can be incorporated within a multilayer scenario tree, such that revised decisions are permitted in each time period based on the realized values of the uncertain events. Moreover, fuzzy quadratic terms are used in the objective function to minimize the variation of satisfaction degrees among the constraints; it allows an increased flexibility in controlling the system risk in the optimization process. Results of the case study indicate that useful solutions for the planning of agricultural water management have been obtained. In the FSWM model, a number of policies for agricultural water supply are conducted. The results obtained can help decision makers to identify desired water-allocation schemes for agricultural sustainability under uncertainty, particularly when limited water resources are available for multiple competing users.