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随着信息时代的到来,企业也在逐渐以信息化管理模式取代传统的管理模式.制造执行系统一方面可以对来自ERP软件的生产管理信息细化、分解,将操作指令传递给底层控制;另一方面,MES也可以实时监控底层设备状态,采集设备、仪表的状态数据,从而将控制系统与信息系统联系在一起,并将生产状况反馈给计划层.本文主要介绍了MES排产模块引入的过程以及遇到的问题,该模块的引入解决了长期以来困扰生产厂的排产瓶颈的问题,大大地提高了生产的效率. 相似文献
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在化工生产中常会使用一些危险品化学品,特别是在化工工艺中由于反应条件多为高温高压,反应激烈,释放大量热量,产生气体,进而引发一些安全事故,如火灾、爆炸等。因此在化工工艺中需要采取一定的措施最大限度地避免安全问题的出现。本文对化工工艺的设计阶段有可能存在的安全问题进行了分析,对安全问题的防治进行了探讨。 相似文献
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随着能源危机的不断加剧,化工工艺的节能措施越来越受到人们的关注。化工工艺是节能工作中的重要内容之一,通过对化工工艺的优化可以实现化工业的可持续良性发展。笔者就对化工工艺的节能措施进行了探讨,以达到化工生产节能的目的。 相似文献
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在化工工艺中,工艺水平主要表现在新型实用技术的应用。而超滤技术作为一门实用而且新型的科学技术,广泛应用于分离浓缩及纯化生物、医药制品领域,还可用于对血液、废水的处理,作为化工生产过程中不可或缺的重要技术被普遍应用。在化工工艺中具有广阔的发展前景。本文就超滤技术的原理,对超滤技术在化工工艺过程中的具体应用做出详细的介绍,最后分析了超滤技术在化工工艺过程中应用的优势。 相似文献
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信息化与数字化的快速发展使得原有的电网调度评价系统开始向信息化方向转变.信息化后的电网调度评价管理系统有着较强的实用性、适应性、可靠性、安全性等一系列特点,对我国电网安全评价体系的发展有着极其重要的意义.经过数字化信息化改进后的电网调度安全评价系统可以方便各级电网调度机构开展电网调度机构安全性评价工作,使得各级电网公司对电网调度评价更加规范,并且可以实现评价工作动态管理、规范管理与全过程管理.本论文对电网调度评价系统信息化做出研究与评价.对以下几个方面进行研究:(1)对当今电网信息化系统主要架构模式进行研究,对以Web数据库、B/S模式和互联网组合的主要架构进行研究.(2)电网调度的信息化数字化是否可以实现科学化、智能化、安全化的管理电网调度安全评价工作.(3)电网调度信息化能否保证系统在可操作性、可维护性以及实时性上有较大改进.(4)电网调度安全评价体系的系统化是否可以保证电网调度系统的安全性. 相似文献
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本文分析当前电网调度系统的运行情况与存在问题,提出在调度自动化系统中建设告警直传、远程浏览功能,以及基于E8000主站系统的应用。在实际应用中,这两项技术对电网调度具有十分重要的意义和推广价值。 相似文献
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随着社会的发展,钢材在我们日常生活中的起着举足轻重的作用。有建筑用钢、汽车用钢、船舶用钢等等。我们公司主要生产高标准轴承钢、齿轮钢、合金弹簧钢、油井管坯钢、易切削非调制钢等优特钢。产品广泛应用于机械、汽车、铁道、船舶、石油、化工、电力和军工等领域。那么就来谈谈关于炼钢中的150t转炉自动控制系统的设计及控制系统的配置和功能,并且对于系统运行中出现的不能满足生产和工艺要求的问题,提出了改进和优化措施。 相似文献
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近年来,我国的化工工业得以迅速发展,化工工艺安全设计作为化工产业中的重要组成部分,是化工工业可持续发展的安全保障。本文主要介绍了化工工艺安全设计中存在的一些问题,并提出一些有效识别和控制安全隐患的方案。供同行参考。 相似文献
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EPA系统通过微网段划分和确定性通信调度控制策略,解决了以太网通信的不确定性问题.本文从分析EPA报文的组成结构入手,研究了EPA确定性通信调度策略的调度通信开销,建立了数据传输报文和调度报文的通信开销数学模型,为EPA通信实时性的定量研究提供了理论基础. 相似文献
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氯碱工业是古老,传统的能源与资金密集型基本化工原料工业。烧碱与氯广泛用于化工、轻工、纺织、冶金、农业、医药、电子、食品等国民经济中。隔膜法电解是目前电解法生产烧碱最主要的方法之一,而其中的蒸发工段是烧碱生产中的重要工段。蒸发所需的加热蒸汽折成等价热值,其数值约占烧碱综合能耗的25豫~35豫,仅次于电解工序。因此,电解液蒸发工序运行状况和生产技术直接影响整个氯碱系统的用能水平和经济效益。本文介绍了氯碱生产各种蒸发工艺的特点。 相似文献
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This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue. 相似文献
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Roy J. Shephard 《Journal of sports sciences》2013,31(7):603-620
The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae. 相似文献
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重新认识体育的社会关联 总被引：3，自引：1，他引：2
体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。 相似文献
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本文在专家访谈、问卷调查、数理统计和文献资料分析的基础上,探析了上海社区体育竞赛参与者的特点、参与者对社区体育赛事运作管理的看法等问题。在此基础上从引进社区体育赛事的志愿者、整合社区体育赛事的各种资源、开发社区体育竞赛的无形资产、组建非营利性的专业团队、规范社区体育赛事的服务管理等方面提出了进一步满足上海社区居民日益增长的体育竞赛参赛需求的对策与措施。 相似文献
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对全面把握游泳训练环节的探讨 总被引：4，自引：0，他引：4
从系统观点出发,结合训练实践,对全面把握游泳训练环节进行探讨。认为应强化非智力因素在运动员多年训练中的作用,在育材全过程中不断选材,从整体上把握动态训练的全过程,把培养高水平运动员的整个过程置于一个严格的科学控制之下。 相似文献
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影响和限制耐力性运动项目的成绩的生理因素是复杂的和多方面的,取决于训练的强度和运动成绩.大强度持续性运动可导致呼吸肌疲劳.运动性呼吸疲劳可能在决定运动耐量方面起到关键的作用：一方面通过直接影响运动肌力量的生成（外周疲劳）,另一方面,通过肢体用力自感不安反馈引起工作肌运动单位输出功率下降（中枢疲劳）.对呼吸肌进行训练,可能有助于提高耐力性项目的运动成绩. 相似文献
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青少年业余足球运动员运动倾向性5因素结构模型初探 总被引：3，自引：0，他引：3
根据Scanlan等人最新提出的运动倾向性理论模型,结合我国实际情况建立了青少年足球运动员运动倾向性5因素结构模型。运动倾向性被定义为:渴望和决心继续参加足球运动的心理状态。所建立的5因素结构模型认为,运动倾向性是由运动乐趣、参与选择、个人投入、社会约束及参与机会5个因素决定。经确定5个决定因素和运动倾向性的操作定义,编制了相应调查问卷,通过对北京市252名青少年足球运动员实测结果,建立运动倾向性及其影响因素的协方差结构模型,用Lisre 18分析的结果表明:该运动倾向性模型比较符合北京青少年足球运动员。其中运动乐趣、个人投入、参与机会和参与选择4因素对运动倾向性有影响;社会约束对运动倾向性影响不大。 相似文献
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The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ? 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity. 相似文献