佛手瓜深加工研究进展与综合开发思路

佛手瓜的产量很高,且营养丰富,适合广泛种植与开发.佛手瓜可以开发成果酱、果冻、果糕、果丹皮、水晶软糖等产品,并可用作提取果胶、抗氧化剂、植物凝集素等产品的原料.从提高经济效益的角度出发,对佛手瓜进行综合开发,是佛手瓜产业链纵深发展的必由之路.     

Control strategy optimization for energy efficiency and harmonic mitigation in multi-series converters

To provide electrical power for the Research System of Superconducting Magnets (RSSMs) including the background field superconducting magnet and the tested superconducting objects, the high power phase-controlled converter will be used to develop the power supply system. However, because of its inner nonlinear feature, the current harmonics and the reactive power are injected into the AC power supply system. To improve the quality of the power supply system for RSSMs, an improved synchronous control strategy is suggested for the superconducting magnet power supply system, which comprises four series-connected six-pulse converters fed by a phase-shifting transformer, respectively. According to the proposed control strategy, the basic unit is two 12-pulse converters and the control method will be changed in terms of load fluctuations which are represented by the per unit value of converter output voltage. As a result, harmonic is greatly reduced but the power factor is also high.     

L-精氨酸高产菌株的亚硝基胍诱变选育和种子培养基的优化研究

为了筛选L-精氨酸的高产菌株,采用亚硝基胍对出发菌株A TCC 14067 （Brevibacterium flavum）进行诱变,结合抗精氨酸结构类似物D-精氨酸,S-甲基半胱氨酸平板抗性筛选高产菌株,并采用正交试验优化了种子培养基.结果显示,经过1 mg/mL的亚硝基胍诱变处理4min后,采用14 mg/mL的D-精氨酸抗性平板和8mg/mL的S-甲基半胱氨酸抗性平板筛选获得精氨酸高产菌株,由于解除精氨酸自身的反馈调节,L-精氨酸积累增大,产酸量达37.2 g/L,比野生菌株提高了128.2％,得到的高产菌株遗传性状稳定.通过对种子培养基进行正交试验优化,确定最终培养基配方为葡萄糖3.0％,玉米浆2.0％,硫酸铵2.0％,KH2PO4 0.10％,MgSO4·7H2O 0.05％,尿素0.15％,在此发酵条件下,L-精氨酸产量达37.8 g/L.     

基于Modbus现场总线的粘胶带涂布机电气控制改造

本文论述了一种利用Modbus现场总线控制原理对老式粘胶带涂布机进行的电气控制改造方案。改造主要针对电气传动控制装置的几个主要环节,包括恒张力放卷、涂布过程多级同步控制、恒张力收卷等方面,以解决了生产线长,环节多对调试、操作、维护带来的不方便,从而提高工作效率。     

序贯设计优化佛手瓜汁生产细菌纤维素工艺

在以佛手瓜汁为原料利用木醋杆菌(Acetobacter xylinus)发酵生产细菌纤维素的过程中,利用Plackett-Burman分部析因试验设计确定出蔗糖质量浓度和pH值对产量具有显著影响,再利用最速爬坡试验确定出这两个因素的中心点,最后以中心点进行中心组合试验设计,建立试验空间下的模型,优化出最佳的因素水平为温度28℃、(NH4)2SO4质量浓度0.3g/100mL、佛手瓜汁用量(体积分数)100%、蔗糖质量浓度6.54g/100mL、pH4.19。在最优条件下可得最大干基产量为4.18g/L。     

Study on the Current-Sharing Control System of the TF Power Supply for a Superconducting Tokamak

The superconducting toroidal field (TF) plays an important role in a superconduct-ing tokamak,whose power supply was developed based on the feedback control principle.In this paper,superconducting tokamaks in different countries are described,and the TF power sup-ply of the International Thermonuclear Experimental Reactor (ITER) is taken as an example to study the current-sharing characteristics in the current-stabilized stage.Firstly,the math-ematical model of the TF power supply is established,and then the 3-loop control method is put forward for achieving the stability and reliability of current-stabilization and current-sharing.Furthermore,further studies indicate that the current-sharing controller has no influence on the current-stabilized control,and current-stabilizing and current-sharing can be realized at the same time.All the work done provides valuable references for the current-sharing design of the TF power supply for a superconducting tokamak,and all these studies lay a solid foundation for developing superconducting tokamaks.     

佛手瓜叶绿素提取及稳定性研究

经过单因素实验及中心组合实验探索,绿皮佛手瓜渣经过干燥过40目筛后,其叶绿素的最优提取条件为以85.93%(v/v)乙醇作萃取剂、料液比1.48%(g/100mL)、温度70℃、回流提取4h,萃取率可达92.6%。所生产的叶绿素产品,对光照、酸性环境、强碱、高于60℃温度及氧化剂敏感。弱碱性、还原性环境、避光、中低温有利于保持叶绿素的稳定性。     

注塑齿轮模具型腔设计方法分析

针对注塑齿轮模具设计精度问题,着重探讨了热变形的影响.采用ANSYS软件对塑料齿轮热变形进行仿真,得到了注塑齿轮在临界固化温度与常温下的齿型变化,通过对比分析指出采用形状放大的方法进行注塑齿轮模具设计会产生较大误差.提出了采用热变形分析得到的齿轮廓线作为注塑模具的最佳型腔,直接编程输入线切割机床可加工出最佳的注塑齿轮模具腔廓面.     

近红外光源对光合细菌生长的影响

光合细菌的光合色素能吸收近红外光进行光合作用.利用加可见光滤光镜的卤钨灯作为近红外光源,照射光合细菌,探讨其对光合细菌生长的影响.结果表明,相对于可见光,近红外光对光合细菌的生长有明显促进作用,可使最大菌体浓度提高45％以上.近红外光照强度饱和区为20W～35W之间,低于20W时,光合细菌的生长速率随光照强度升高而升高;超过50W后,近红外光对光合细菌产生抑制作用.温度和pH值2个培养参数对近红外光的光照效果没有明显的影响.     

冷轧钢卷挫、划伤缺陷产生机理及其治理技术

针对冷轧钢卷卷取后带钢表面出现挫、划伤缺陷的问题,对缺陷宏观与微观形貌进行了分析,研究了冷轧钢卷卷取后带钢表面的挫、划伤缺陷的形成机理,即带钢在卷取过程中沿卷筒周向的静态卷取张力不能与动态的摩擦力相平衡而造成带钢层与层之间的打滑碰撞,导致带钢表面出现挫伤和划伤缺陷。为此,从卷取张力、速度波动的抑制,张力制度的优化,设备的维护,运输装备的改造等方面提出了相应措施,并将其应用到某2 030 mm五机架冷连轧机组,挫、划伤缺陷的发生率从1.2%下降到0.1%,保证了产品质量,取得了较大的经济效益。