LOGO!控制器在纺织厂空调系统中的应用

将西门子公司的LOGO !可编程控制器和电动机变频技术应用于纺织厂空调系统中 ,既克服了现有系统的不足 ,又提高了系统可靠性 ,降低了能耗 ,满足了各车间的工艺要求 ,保证了纺织产品的质量 ,经实际使用表明该方案是合理的 ,并可以在同类场合使用     

烹调油烟的免疫毒理学研究进展

烹调油烟是室内主要空气污染物之一，化学成分复杂，严重影响职业接触人群的健康．对烹调油烟免疫毒性的研究是全面评价其毒性作用的一个重要方面．对近几年来烹调油烟影响机体细胞免疫、体液免疫和巨噬细胞以及NK细胞功能等免疫毒性方面的研究进展作一综述．     

内镜下气囊扩张治疗贲门失弛缓症的近、远期疗效

目的 :回顾气囊扩张治疗贲门失弛缓症的近、远期疗效及治疗过程中的经验。方法 :对经食管吞钡X线拍片确诊的 16例贲门失弛缓症患者 ,采用内镜下气囊扩张治疗并评价其近、远期疗效。结果 :近期疗效 :16例患者中 ,12例 (75 % )显效 ,4例 (2 5 % )有效 ,总有效率为 10 0 % ;远期疗效 :16例患者中 ,1例 2周后复发经再次扩张治疗后未复发 ,另有 1例在治疗后的半年内复发扩张治疗后 ,半年再次复发 ,经直径 4 .0cm气囊扩张后 4年未复发。结论 :气囊扩张治疗贲门失弛缓症有效、易操作、安全、并发症少及复发率低 ,但有较多的细小经验及体会值得总结 ,以便更完善和更成熟。     

Towards Enhancement of the Economy of a Thermal Power Generating System through Prediction of Plant Efficiency

The plant ‘Heat Rate’ (HR) is a measure of overall efficiency of a thermal power generating system. It depends on a large number of factors, some of which are non-measurable, while data relating to others are seldom available and recorded. However, coal quality (expressed in terms of ‘effective heat value’ (EHV) as kcal/kg) transpires to be one of the important factors that influences HR values and data on EHV are available in any thermal power generating system. In the present work, we propose a prediction interval of the HR values on the basis of only EHV, keeping in mind that coal quality is one of the important (but not the only) factors that have a pronounced effect on the combustion process and hence on HR. The underlying theory borrows the idea of providing simultaneous confidence interval (SCI) to the coefficients of a p-th p(≥1) order autoregressive model (AR(p)). The theory has been substantiated with the help of real life data from a power utility (after suitable base and scale transformation of the data to maintain the confidentiality of the classified document). Scope for formulating strategies to enhance the economy of a thermal power generating system has also been explored.     

串联冰蓄冷系统设计中的泵能耗分析

介绍了串联冰蓄冷系统设计中泵能耗的3种节能方法：串联泵，变频泵和制冷机旁通，通过对某工程实例的模拟计算，对比分析了这3种方式的节能效果，提出了有效的节能方式。     

涡轮叶片尾缘针肋的换热研究

以涡轮叶片尾缘中针肋通道的换热为研究对象，讨论并计算出了一定条件下获得最大针肋通道换热量时针肋的形状曲线和换热优势，系统分析了这种拥有最佳形状曲线针肋的通道散热量随针肋物性参数及几何特征变化的规律。     

A Two-dimensional Heat Transfer Model for Atmosphere-land System in the Lake-dominated Alaskan Arctic

1 Introduction Shallow tundra lakes are one of the dominating landscape features in the Alaskan Arctic. They typically cover 20% of the total area of the North Slope of Alaska, and up to about 40% in the coastal plain [1,2]. Many lakes are, in their entirety or in part, shallower than the maximum annual ice thickness, consequently, some ice freezes completely to the lake bottom, nevertheless, large areas of water are deeper than the maximum ice thickness and the ice remains afloat througho…     

Nonparametric smoothing in the analysis of air pollution and respiratory illness

While most of epidemiology is observational, rather than experimental, the culture of epidemiology is still derived from agricultural experiments, rather than other observational fields, such as astronomy or economics. The mismatch is made greater as focus has turned to continue risk factors, multifactorial outcomes, and outcomes with large variation unexplainable by available risk factors. The analysis of such data is often viewed as hypothesis testing with statistical control replacing randomization. However, such approaches often test restricted forms of the hypothesis being investigated, such as the hypothesis of a linear association, when there is no prior empirical or theoretical reason to believe that if an association exists, it is linear. In combination with the large nonstochastic sources of error in such observational studies, this suggests the more flexible alternative of exploring the association. Conclusions on the possible causal nature of any discovered association will rest on the coherence and consistency of multiple studies. Nonparametric smoothing in general, and generalized additive models in particular, represent an attractive approach to such problems. This is illustrated using data examining the relationship between particulate air pollution and daily mortality in Birmingham, Alabama; between particulate air pollution, ozone, and SO₂ and daily hospital admissions for respiratory illness in Philadelphia; and between ozone and particulate air pollution and coughing episodes in children in six eastern U.S. cities. The results indicate that airborne particles and ozone are associated with adverse health outcomes at very low concentrations, and that there are likely no thresholds for these relationships.     

上海市空气污染造成人群健康经济损失的研究

文章通过对上海市空气污染季节性状况的描述 ,分析了各种污染物的污染程度和变化趋势 ,并利用对上海某市级医院的实地调查数据 ,对空气污染物与医院呼吸系统疾病患者日门诊量之间的相关关系进行研讨 ,建立了多元分析模型 ,探讨了患者健康经济损失的计量方法 ,并对由空气污染造成呼吸系统疾病患者健康经济损失进行了估算。研究表明 ,在其他条件不变的情况下 ,NOX 日指数每增长 10 % ,被调查医院呼吸系统疾病患者的日门诊人次增加 7 7人次 ,而这些疾病患者由于患病产生的年度健康经济损失为 2 11万元。据此作保守的推断估计 ,上海市一年内因NOX 超标而发生的呼吸系统疾病门诊行为造成的健康经济损失可以达到 4 2亿元。同样 ,SO2 和TSP造成门诊患者的健康经济损失分别为 1 5亿元和 0 86亿元     

平板非稳态导热逆问题的近似解

对一维物体非稳态加热或冷却的表面温度的计算进行了研究，在增加一个参数的基础上，采用积分求解的方法，获得了一个近似解，此解不仅表达式简单，便于应用，而且具有较高的准确度，该表达式还可方便地应用于变异热系数的场合。