锅炉汽包水位的自动控制应用研究

根据转炉炼钢的生产特点,设计了余热锅炉自动补水控制系统。在分析了汽包水位的动态特性后,根据其特点选择合适的控制方案,分别设计了单冲量控制、双冲量控制和三冲量控制系统。并总结了每种控制系统的适用场合,为生产的正常进行提供及时的指导,为安全生产创造了必要的先决条件。     

浅谈35T角管式锅炉中汽包液位的控制

三冲量控制原理的锅炉汽包液位控制是一种先进的控制方式,它改变了以往单回路控制难以满足锅炉水位控制要求的情况,保障了锅炉的安全、稳定运行。     

汽包锅炉串级三冲量给水全程控制系统设计

本次设计中主要对大型火力发电机组的给水全程控制系统进行了分析，对它的工艺要求以及实现方法进行了详细阐述。在；气包锅炉给水自动调节中，为了减少或抵消虚假水位现象，我们采用串级三冲量调节系统。本设计里，详细介绍了串级三冲量给水控制系统的工作原理，对调节器的参数进行了理论分析与设计，并在MATLAB环境中进行了模拟仿真，通过仿真结果我们发现，串级三冲量给水控制系统能够很好地满足给水控制系统的要求。     

MEMS固体化学微推进阵列的微冲量测试技术

为了评价MEMS(Micro Electro Mechanical Systems)固体化学微推进阵列的推进性能,对其单元微冲量的精确测试显得尤为重要。在传统冲击摆的基础上,考虑微推进器推力和燃气射流冲击力之间的比例关系,设计了一套适用于MEMS固体化学微推进阵列单元微冲量的间接测试装置,并成功用于6×6规格(单元集成度为36个/cm²)微推进阵列的实际测试中。结果表明:典型实验数据下的待测微冲量为2.5442×10-4Ns,相对误差小于5%；实测8个单元的微冲量平均值为2.5574×10-4 N·s,相对偏差较小,具有很好的重复性。      

休闲食品产业信息

康师傅净利润首超日清;山东钙奶饼干：一线品牌冲量，新锐品牌跟进;湖雪集团进军饼干业；     

基于DCS的锅炉自动控制系统

介绍了以组态软件为上位机监控系统和以PLC为核心的下位机的锅炉集散控制系统的实现方案,简述了DCS锅炉控制系统的硬件配置及其功能的软件实现,燃烧控制系统、汽包水位控制系统及流量控制系统的主要特点和控制流程。实践证明,该系统达到了锅炉燃烧节能降耗的工艺要求,且运行稳定可靠。     

邻炉高温汽水推动法缩短机组启动时间探讨

汽包缺水事故是电力生产企业重点防范的二十五类事故之一,发生此类事故如不能正确操作,盲目上水,会造成汽包上、下壁温差继续增大,甚至由于温差应力而造成水冷壁大面积爆管、汽包严重拱曲变形等严重事故,研究合理上水方案,可以缩短机组启动时间,提高机组运行经济性。本文将主要介绍我厂循环流化床锅炉在实际运行中总结的运行经验,期望给采用同类型循环流化床锅炉技术的生产企业提供可靠、实用的参考。     

锅炉汽包双室平衡容器的应用与研究

本文主要介绍了锅炉汽包双室平衡容器的特性,并对其的应用进行了详细的分析和研究,提出了一套简洁易行的补偿方案,并对双室平衡容器常见的水位指示失真进行了分析讨论.     

锅炉停炉后壁温差的控制方法

对湛江奥里油发电厂DG2030/17.4-1(1)型锅炉停炉后汽包壁温差偏大的原因进行了分析,认为其主要是因停炉后汽水系统压力下降速度过快、汽包水位偏低、补水频繁、停炉后放水速度过快、强行通风进行快速冷却不当等所致.对此,提出尽可能减慢停炉后汽压下降速度、采用滑参数停炉方式,以及在维持汽包较高水位前提下尽量减少补水次数的控制对策.在采取这些对策后,停妒后汽包壁温差基本控制在允许范围内.     

HT-L汽包系统管线腐蚀问题的探讨及对策

介绍了航天炉汽包系统的工艺流程,分析了汽包系统在运行过程中存在的问题并提出了相应的解决措施,总结了改进后的效果。结果表明,通过一系列的改进措施,汽包系统运行平稳,管线严重腐蚀的问题得到了有效的解决。     

Store-Switching Behavior

This study describes temporal aspects of consumer shopping behavior.Most cross-sectional studies either explicitly or implicitly assumethat consumer choice behavior is constant over time. The results ofthis study, which is based on scanner panel data for twenty-one grocerystores for three years in Missouri, indicates that consumers areinvolved in substantial store-switching and variety-seeking behavior,the degree of which is related to a set of sociodemographic variables.     

关键描述变量在市场细分中的中介作用研究

描述变量研究中存在的问题以及营销实践中的困惑要求研究者构建一种新的市场细分范式.文章根据有关学者提出的模型进一步在描述变量中提炼出关键描述变量的概念,认为主要由客观需要、目标价值观、信号价值观和消费资源构成的关键描述变量对人口统计因素等基本描述变量与行为变量之间的关系具有中介作用,以私家车为例的实证结果也基本支持了这一假设.文章建议营销者可尝试采用新的市场细分范式,即对消费者的关键描述变量进行直接测量和细分,然后一方面用来解释和预测消费行为,为怎样营销服务;另一方面用来寻找相应的人口统计特征,进而为哪里营销服务.     

Determinants of retirement planning behaviour and differences by age

This paper presents the results of an investigation into the determinants of retirement planning behaviour and differences among three age groups: 21‐ to 39‐year‐olds, 40‐ to 59‐year‐olds and those aged 60 years and older. A national survey of 911 individuals from households with incomes of $75 000 or greater was conducted in the US. The significance of socio‐demographic variables, the ability to recover from loss, behavioural tendencies and perceived or actual personal control were investigated; together with their role in the prediction of maximization of retirement contributions and ownership in the personal individual retirement account (IRA) or Keogh accounts. The results identified several significant variables in the prediction of ownership in a personal IRA or Keogh, including age, sources of financial information, being an early investor and investor activity. The results also identified several significant variables in the prediction of the maximization of retirement contributions, including employment, income, savings activity, ex ante research, review of investment performance, early investor, investor activity, such as planning for financial future, setting up automatic deposits and reviewing financial information in the mail.     

The Impact of Organizational and Environmental Variables on Strategic Market Orientation

Abstract

This paper offers a new look at market orientation by conceptualizing it from a strategic perspective. It differs from the current literature in that it develops a measure that emphasizes managerial attitudes and strategic intent. The new measure is empirically scrutinized by an investigation of its relationship with pertinent organizational and environmental variables, as well as company performance. Based on a survey of nearly 400 companies operating in the U.S., significant relationships emerged between Strategic Market Orientation and three organizational variables, namely strategic priorities, inter-departmental coordination and ownership nationality. Two of the environmental variables, namely intensity of competition and rate of technological change were also significantly related to Strategic Market Orientation. The relationship between Strategic Market Orientation and company performance remained inconclusive.     

The Economic Psychology of Stock Market Bubbles in China

The Chinese stock markets were extremely volatile during the period 2005–08. The Shanghai Stock Exchange (SSE) Composite Index increased more than sixfold from 1,012 in 2005 to 6,124 by the end of 2007. It then declined continuously to reach a low of 1,929 on 17 September 2008, or a drop of 70 per cent from its peak in less than 10 months. Although the market downturn may have been affected by the financial crisis in the United States and the rest of the world, the extreme fluctuations of stock prices signify a big market bubble, and the burst of that bubble must be explained by intrinsic characteristics or the economic psychology of Chinese investors. Based on a detailed market data analysis, this paper attributes the development of the stock market bubble to three key psychological factors: ‘greed’, ‘envy’ and ‘speculation’, and the burst of the bubble to three contrasting factors: ‘fear’, ‘lack of confidence’ and ‘disappointment’. It concludes that only after Chinese companies become really commercialised and profitable and investors become rational can the stock markets become stable without extreme volatility as seen in the past. Government policies can play a role in soothing market volatility detrimental to shareholders and the wider economy, but investors should not depend on government for making their own investment decisions.     

Perceptual Variables and Nascent Entrepreneurship

Using a large sample of individuals in 28 countries, we investigate what variables are significantly correlated with an individuals decision to become an entrepreneur. Following existing literature in economics, we link such a decision to demographic and economic characteristics. In addition, we argue that perceptual variables such as alertness to opportunities, fear of failure, and confidence about ones own skills are also important. Our results suggest that perceptual variables are significantly correlated with new business creation across all countries in our sample and across gender. Although our data do not allow the identification of causal relationships, our findings suggest that, when making decisions, nascent entrepreneurs rely significantly on subjective and often biased perceptions rather than on objective expectations of success. Thus, perceptual variables should be included in economic models of entrepreneurial behavior.JEL CODE: M13, J24, D01     

我国首次公开发行制度变迁外生变量的影响因素分析

本文认为,我国现在甚至以后影响首次公开发行制度变迁的主导因素已经由改革之初的政府利润预期变为不断出现的市场发展与现行制度的内在矛盾,但外生变量仍具有积极作用。第一,政府和其他制度变迁主体之间具有较强的利益相关性,这使得政府确定的外部规则与其他制度主体所创造的内部规则有激励兼容的可能,政府引进的外部规则有助于内部规则的发育;第二,政府在外部规则创新过程中会同时引进和发现许多制度知识,这些知识会通过各种途径传播开来,从而节约其他制度变迁主体的制度创新成本;第三,其他制度变迁主体之间存在的竞争迫使它们选择相互妥协的制度变迁方案,而成功的市场化经历或失败的市场化教训会吸引政府直接应用符合市场经济的一般规则,缩短其他制度变迁主体制定内部规则的时间。     

中国经济的真实收敛速度——基于模型方法的改进

经济增长收敛性是新古典增长理论做出的关键性预测,但是国内相关文献测算的收敛速度普遍偏高。文章通过慎重选取控制变量,同时考虑空间相关性和控制变量间可能存在的共线性,在提取主成分的基础上估计空间面板模型,得到的收敛速度仅为2.36%。这一结果既与国外文献的经验值更为接近,也与我国的经济现实更为相符。这启示我们,在研究经济增长的收敛机制时,既要慎重选择有关的控制变量,也要恰当地选择模型估计方法。     

开放条件下不同泰勒规则在中国的适用性研究

通过构建开放经济条件下同时存在后顾性变量和前瞻性变量的新凯恩斯主义DSGE模型,利用MATLAB随机数值模拟比较分析三种不同泰勒规则在中国的应用性问题。结果表明,总需求冲击加剧了产出的波动,而总供给冲击不利于通货膨胀的稳定。比较福利后,发现简单的名义利率泰勒规则比复杂的泰勒规则更加适合于中国目前的经济发展状况。央行在设定目标损失函数时,应该减少汇率的权重,而增加通货膨胀的权重,这有利于减少中国居民整体福利的损失。     

宏观经济变量冲击与我国银行间市场风险传染

虽然宏观经济变量对我国银行同业拆借市场的影响比较小,但随着时间的推移,风险传染规模呈扩大趋势,同时银行风险的溢出效应比较明显。本文模型结构和模拟结果显示的四个特征表明,监管当局在防范我国银行风险传染方面不仅要关注宏观经济变量冲击的负面影响和银行在同业拆借市场中的具体交易情况,还需要关注银行风险的传染源和风险溢出效应。监管机构可以通过建立银行偿付水平对应于不同宏观经济变量的敏感系数,时刻关注宏观经济的异常波动对银行偿付能力的影响。