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.     

高校贵重仪器网络化管理模式的构建与实践

贵重仪器设备的管理和使用逐渐成为如今各高等院校所关注的问题.为提高贵重仪器设备的使用率,促进资源共享,充分发挥贵重仪器设备的使用价值,暨南大学对此进行改革,改进运行机制和管理手段,建立“贵重仪器设备管理与效益分析系统”,实行网络化管理.该系统具有仪器使用预约管理、仪器使用授权管理、仪器使用收费管理三大功能.同时建立激励机制,培养高技术水平的设备管理人员,形成贵重仪器设备使用与管理的良性循环,使贵重仪器设备更好地为学校教学科研工作服务,更好地创造价值.     

高校实施教师激励机制实践的探索

在高校中采取相应的激励机制对学校的发展起着十分重要的作用。目前怎样制定和实施合理的激励机制是高校管理者和研究者努力探索的问题。文章从激励机制入手,结合不同高校在实施激励机制过程中存在的诸多现象,分析问题,总结经验,探讨如何充分发挥激励作用,调动高校教师的工作积极性,加强高校师资队伍建设,以期促进高等教育改革。     

Development of integrated precision vibration-assisted micro-engraving system

A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and PID control algorithm was established to guarantee specific precision. Apart from experimental validation of the performance of the system, various micro-V-grooves cutting experiments on aluminum alloy, ferrous material and hard cutting material were performed, in which Kistler force sensor was used to measure cutting force. Through experiments, it was clear that the vibration-assisted micro-engraving system can ensure good quality of micro-V-grooves and reduce cutting force by about 60% compared with traditional removal process without ultrasonic vibration.     

基于MATLAB的结构可靠度分析方法研究

基于结构可靠度分析方法—JC法、蒙特卡罗法和响应面法的基本原理,利用MATLAB软件对算例编制了相应计算程序,并对计算结果进行了比较.计算结果表明,利用MATLAB可以编制结构可靠度分析程序,计算结果较快,数据合理,并为复杂结构的可靠性分析提供参考.     

某热轧厂除鳞系统改进探讨

针对某热轧厂2250mm热连轧机组在生产家电、汽车板等高端产品的原料带钢产品表面存在氧化铁皮等缺陷,从分析氧化铁皮的形成和最佳除鳞装置设置等方面入手,总结、借鉴国内先进的热连轧生产技术和专利,制定有效措施和可行的技术方案,实现热轧带钢表面彻底消除一次氧化铁皮、二次氧化铁皮,严格控制带钢表面三次氧化铁皮残留量,以提高产品表面质量。     

论中小制造业企业实施绿色管理的动因及途径

市场的绿色消费需求、政府的引导与监管、国际绿色化运动浪潮、企业的持续经营目标等是驱使中小制造业企业绿色管理行为产生的主要动因。为此,政府应通过管理体制的绿色转型、公众绿色消费意识的培育、绿色管理资金支持力度的加大、绿色关键技术开发的加强等途径促进中小制造业企业实施绿色管理;从中小制造业企业自身来说则应通过经营理念的转变、企业内部绿色管理体系的构建以及企业间合作的加强等途径来加快实施绿色管理的进程。     

大学生入党动机调查与分析

当前大学生的入党动机可以分为主动型、被动型和模糊型,应客观地看待大学生的入党动机现状,分析不端正的入党动机产生的原因,采取有效对策,引导大学生树立正确的入党动机.     

建构主义理论指导下的高职英语口语教学策略

建构主义理论强调要以学习者为中心,通过学生的自主学习、协作学习和情境教学等,让学生主动建构自己的英语口语交际能力和语用能力,为大学英语口语教学提供了新的模式。教师应在建构主义理论指导下,积极更新教学策略,改变传统教学模式,提高教师自身素质,并激发学生学习英语的兴趣和动机。     

The role of personality in motivational regulation and academic procrastination

This study explores the role of the motivational self-regulation in academic procrastination under the personality framework. Therefore, the aims of the study were to investigate: (a) the role of personality dimensions in the self-regulation of motivation; (b) the role of self-regulation of motivation in procrastination; and (c) the mediating role of the self-regulation of motivation. The participants were 274 university students (M?=?21 years). The Big Five traits explained from 6% to 17% variance of the individual motivational regulation strategies (MRSs). Both personality (conscientiousness) and the MRS (environmental control) were significant predictors of academic procrastination. Conscientiousness, agreeableness, and intellect showed an indirect effect on reducing academic procrastination, mediated through the strategy of environmental control, thus additionally suggesting the important role of this motivational strategy. Since this strategy can be taught, these findings have a strong practical value.