磁悬浮式驱动织针原理及试验方法探讨

在分析针织提花机传统选针原理和磁悬浮技术的基础上,提出一种新的磁悬浮式驱动织针模式,该模型以电磁-永磁混合驱动为基础,对电磁驱动织针进行编织原理研究与试验方法探讨。验证了磁悬浮式驱动织针模式下选针方式的可行性;同时对试验数据进行分析,验证悬浮驱动理论模型的正确性。将单织针控制原理扩展延伸到多织针控制,并对多织针悬浮驱动模式的控制策略进行探讨,为实现磁悬浮式驱动织针实用化奠定基础。     

软起动器在饲料加工行业中的应用

三相交流异步电动机的广泛使用对电动机的起动方式要求越来越高,针对传统降压起动方式的二次电流冲击问题,提出电机的软起动。主要介绍了软起动器的工作原理、起动方式、大功率设备电机的控制、典型电路等,概述了软起动器改善设备运行的优点及意义。     

感应加热电源耦合系统的控制研究

为了实现对工件的梯度加热,需要采用多个感应线圈对工件进行分段加热。针对多个感应线圈之间存在功率耦合的问题,采用解耦控制策略对耦合系统进行控制。设计了两级式感应加热电源耦合系统实验样机,并对耦合系统中主机、副机的控制设计进行重点介绍。仿真分析和实验结果表明,耦合系统中主机、副机可以实现功率独立输出。     

变频型空调在提高电网电压稳定性方面的应用

近年来由于电网电压崩溃而引起的电网事故多有发生,因此电网电压稳定性问题引起了广泛关注。区别于以往从发电侧控制的解决策略,文章尝试从负荷侧着手利用可控负荷来提高电网电压稳定性。选取了在都市负荷中比重逐渐扩大的变频空调负荷作为可控负荷范例,参与电网电压稳定性控制。首先对通过对变频空调的原理分析,建立了相应的数学模型,之后针对电网瞬时停电,电网电压跌落等情况,对变频空调的控制策略进行了改进,提出了一种自主控制策略,该控制策略无需通信设备,通过变频空调对电网电压的实时监测,可在电网电压故障情况下,通过主动调节变频空调吸收的功率缓解对电网的有功无功冲击,最后,通过MATLAB仿真分析,对该控制策略进行了验证。     

毛织物丝边张力控制

对织造经轴边丝线张力控制不当造成的丝线拖边问题进行了研究分析，并通过大量工艺跟踪，多品种试验，找出了相应的解决办法，制定了切实可行的措施，效果明显。     

磨煤机解耦控制系统的设计和仿真

中储式磨煤机出口温度和入口压力系统是一个耦合作用较强的双输入双输出系统,使用常规PID控制回路进行控制无法取得理想效果。针对这种情况,提出了一种解耦PID控制策略。该方案在PID回路中加入解耦补偿器,以实现对多变量的解耦控制。仿真试验表明,该策略有效地解决了多变量的耦合问题,取得了较好的控制效果。     

电动机软起动器的应用优势

电动机软起动器是近年来在国内出现的新技术,具有节电效率高,软起动特性好等特点。对于大型企业,在动力设备中的应用,节能降耗的意义将十分重大。通过对电动机软启动器节电原理的阐述,及电动机起动技术的分析,提出了应用电动机软起动器的优势和电动机软起动器在动力设备上的实际应用。     

拖链刮板式浸出器的应用研究

为了进一步提高油厂对拖链刮板式浸出器的认识,介绍了拖链刮板式浸出器的结构,着重阐述了其设计、制造过程中的要点及运行中应注意的问题。通过生产实践,利用该浸出器对大豆坯进行浸出,可使粕中残油达到0.6%~0.8%。     

分析CRTSI型双块式无砟轨道施工质量控制

针对CRTSI型双块式无砟轨道施工质量控制课题,结合实际案例,做了简单的论述,总结了质量控制策略和措施,共享给相关人员参考。通过分析以往CRTSI型双块式无砟轨道常见施工质量通病,提出有效的质量控制措施,以确保工程实体质量达标。     

纸机负荷分配的耦合特性分析与仿真研究

根据纸机传动系统中存在的负荷分配易失衡等特点,分析了单分部间多电机拖动同一负载时传动点间耦合关系的特性,基于交流异步电机空间矢量控制的数学模型,提出了刚性耦合负荷分配采用总线通信转矩控制,以及柔性耦合负荷分配采用总线通信转速控制的控制策略;再利用MATLAB/SIMULINK软件对这两种控制策略进行建模与仿真,最终验证了两种控制策略的可行性与实用性。     

几种软启动器的比较及其在盘磨中的应用

在对三相异步电动机的几种软启动器的分析比较之后，提出了一种以晶闸管软启动器为核心，利用一台软启动器启动三台盘磨电机的电控系统。实际应用效果证明了该系统的有效性。     

软启动器及其在打浆盘磨中的应用

介绍了三相异步电动机的几种常用启动方式,并针对造纸厂打浆车间盘磨主电机启动中存在的一些问题,提出了一种以可编程控制器(PLC)为核心,利用1台软启动器启动3台盘磨的电控系统。实际运行效果表明,该电控系统具有可靠性好、性能完善的优越性。     

发酵香肠中生物胺含量影响因素的研究进展

介绍生物胺的种类、危害及在发酵香肠中存在的可能,重点分析了原料肉、发酵剂、工艺条件(温度、pH值、香肠直径、辅助配料、贮藏条件)等因子对发酵香肠中生物胺含量的影响,并提出了通过控制原料肉的卫生质量、使用优良的发酵剂、控制蛋白质的水解程度、使用添加剂等措施降低发酵香肠中生物胺含量。     

Evaluation of starter diet crude protein level and feeding regimen for calves weaned at 26 days of age.

The objectives of this study were to evaluate two levels of CP in starter diets offered to calves weaned on d 26 and to compare postweaning intake of starter diets and performance of calves weaned at 26 or 42 d. Forty Holstein calves were housed in individual outdoor hutches and assigned to one of four treatments. Treatments consisted of weaning on d 26 after offering a 20% CP starter diet from d 1, or d 21, or after offering a 25% CP starter diet from d 21, or weaning on d 42 after offering a 20% CP starter diet from d 1 (control). Between d 42 and 84, calves were commingled in outdoor group pens. On d 42, BW of control calves was heavier than that of early weaned calves. On d 84, BW did not differ among treatments. Consumption of starter diet was not affected by the age at which it was first offered. Weaned calves consumed more starter diet than controls from d 29 to 42. Postweaning performance was not affected by increasing CP in the starter diet. Weaning treatment did not affect the incidence of scours. Comparison of CP intakes with current NRC recommendations suggests that CP requirements for young milk-fed calves are adequate.     

The effects of cultivating lactic starter cultures with bacteriocin-producing lactic acid bacteria

The effects of bacteriocins produced by six strains of lactic acid bacteria on 9 mesophilic and 11 thermophilic commercial starter cultures were investigated in mixed cultures of commercial starters with bacteriocin-producing strains in milk. The bacteriocins produced by the test organisms were nisin A, nisin Z, lacticin 481, enterocin AS-48, a novel enterocin, and a novel plantaricin. Mesophilic commercial starters were in most cases tolerant of bacteriocins, with only two of the starters being partially inhibited, one by four and the other by two bacteriocins. The aminopeptidase activities of mesophilic starters were generally low, and only one of the combinations of mesophilic starter-bacteriocin producer gave double the aminopeptidase activity of the starter culture without the bacteriocin producer. Thermophilic commercial starters were more sensitive to bacteriocins than mesophilic starters, with six thermophilic starters being partially inhibited by at least one of the bacteriocins. Their aminopeptidase activities were generally higher than those of the mesophilic starters. The aminopeptidase activities of seven thermophilic starters were increased in the presence of bacteriocins, by factors of up to 9.0 as compared with the corresponding starter cultures alone. Bacteriocin-producing strains may be used as adjunct cultures to mesophilic starters for the inhibition of pathogens in soft and semihard cheeses, because mesophilic starters are rather tolerant of bacteriocins. Bacteriocin producers may also be used as adjunct cultures to thermophilic starters of high aminopeptidase activity, more sensitive to lysis by bacteriocins than mesophilic starters, for the acceleration of ripening in semihard and hard cheeses.     

红曲菌在酿酒过程中的生产应用试验研究

以宋河中高温大曲为实验材料,筛选出1株红曲菌,以该株红曲菌为研究对象生产出具有较高酯化力的酯化红曲,酯化红曲酯化力达到680 U,是中高温大曲的3倍以上,该酯化红曲应用于酿酒生产过程中能明显提升原酒质量,生产出的原酒窖香浓郁,复合香气好,绵柔度好,后味净,风格突出,对原酒产量也有一定的促进作用。     

电机软启动器的应用

论述了对于鼠笼型三相异步电动机在智能控制中的几种启动方式及其优缺点。介绍了电子软启动器的应用。     

软启动器在水箱拉丝机中的应用

介绍电子软启动器在不需调速的水箱拉丝机中的应用。软启动方式与传统启动方式几方面的对比结果表明 :用软启动器启动可降低对供电电网质量的影响 ,改善电机启动特性 ,减小启动对机械设备的冲击 ,降低设备运行和维护成本等 ,是今后发展的方向     

Thermally-dried immobilized kefir on casein as starter culture in dried whey cheese production

The aim of the present study was to evaluate the use of thermally-dried immobilized kefir on casein as a starter culture for protein-enriched dried whey cheese. For comparison reasons, dried whey cheese with thermally-dried free kefir culture and with no starter culture were also produced. The effect of the nature of the culture, the ripening temperature and the ripening process on quality characteristics of the whey cheese was studied. The association of microbial groups during cheese maturation suggested repression of spoilage and protection from pathogens due to the thermally-dried kefir, as counts of coliforms, enterobacteria and staphylococci were significantly reduced in cheeses produced using thermally-dried kefir starter cultures. The effect of the starter culture on production of volatile compounds responsible for cheese flavor was also studied using the SPME GC/MS technique. Thermally-dried immobilized kefir starter culture resulted in an improved profile of aroma-related compounds. The preliminary sensory evaluation ascertained the soft, fine taste and the overall improved quality of cheese produced with the thermally-dried immobilized kefir. The potential of protein-based thermally-dried starter cultures in dairy products is finally highlighted and assessed.