湿法脱硫入口SO_2浓度对脱硫效率影响的非线性回归分析

通过对太原二电厂11号FGD现场168运行数据采用一元非线性回归分析和基于距离判别法的多元非线性回归分析两种不同的分析方法,利用最小二乘曲线拟合法建立了不同出口SO2浓度范围内的入口SO2浓度与脱硫效率的非线性回归方程,为实际运行过程中脱硫效率的预测和分析提供理论依据。此外,分析了入口SO2浓度对脱硫效率的影响,为运行人员在实际运行过程中提高脱硫效率而提供控制思路。     

How near is near? The distance perceptions of residents of a nuclear emergency planning zone

This paper reports the results of a study conducted within the emergency planning zone (EPZ) of the Nine Mile Point (NMP) nuclear complex located in Oswego County, New York. An EPZ is the area in the vicinity of a nuclear power plant for which detailed plans are implemented for the management of emergencies and for the communication of the risks of nuclear energy production. EPZs are subdivided into emergency response planning areas (ERPAs) according to distance from the plant. This study aimed at discovering how residents of the NMP EPZ perceived distance to the nuclear plant. Distance was conceptualized in five different and complementary ways: estimated straight line distance, estimated driving distance, actual straight distance, actual driving distance and perceived distance. The results indicate that people living at a very short distance from the nuclear plant perceive and estimate distance differently than people living farther away. These results have policy implications and suggest alternative and potentially more efficient ways to redesign ERPAs. Fundamental geographic variables and concepts such as distance, location, proximity and their associated human perceptions are important human dimensions of risk analysis. These results should be of interest to nuclear emergency planners and are probably applicable to many other hazard planning activities.     

基于植被指数的GF-1与Landsat-OLI石漠化识别能力对比评价

植被指数是运用多源遥感影像提取石漠化过程中的主要参考指标之一。为了在石漠化提取中选择最优植被指数,论文以GF-1和Landsat-OLI为源数据,运用欧氏距离对多种植被指数在石漠化提取过程中的可分性和类型识别能力进行了定量的对比评价。结果表明：Landsat-OLI在石漠化与非石漠化、不同等级石漠化信息提取的可分性上略优于GF-1,共有71个参数的欧氏距离大于等于阈值1.56;通过植被指数光谱特征,可以对非岩溶区与石漠化地区进行较好的区分,其类型间欧氏距离普遍高于阈值;然而由于相邻等级石漠化之间植被覆盖率存在渐近式过渡关系,在遥感影像上光谱反射率接近,比间隔等级石漠化更加难于区分。在石漠化类型识别能力方面,波段差和比方法优于单一光谱指数。对于GF-1和Landsat-OLI而言,石漠化信息提取中推荐使用的最优植被指数均为NDVI,其次为GRNDVI。     

陕京二线输气管道风险预评价

采用EST法对建设中的陕京二线输气管道进行了风险评价,得到了管道的高风险区段.通过对评价结果的分析,得出了造成各管段风险值较高的原因,并提出了相应控制措施.     

不同火源功率及火源—出口距离对隧道火灾临界风速的影响研究

由于隧道特殊的建筑结构,其发生火灾时的危害性,相比于其他类型的火灾要严重的多。在隧道的消防设计中,运用纵向风排烟是隧道火灾一项重要的消防措施,如何利用纵向风的特性来有效地引导隧道火灾烟气的运动需要进行系统的研究。运用FDS数值模拟的方法进行研究。结果显示,临界风速随着火源功率的增大而增大;并且随着火源与隧道出口距离的增大呈现出线性增长的趋势。对于6.0cm和9.0cm的火灾,临界风速与火源-出口距离关系式分别为 y=0.4+0.14x, y=0.5+0.11x。因此在消防实际应用中,应当充分考虑不同火源功率和火源在隧道中的相对位置对火灾烟气运动的影响,调节不同的排烟风速进行有效、合理的隧道排烟。     

便梁施工时铁路轨道安全性试验研究

为了保证列车在铁路便梁施工时安全运行,需要对铁路轨道的安全性进行研究。首先要对列车进行3个阶段的测试,即限速阶段、试验车测试阶段、监测阶段,测试每个阶段中钢轨的内、外轨垂直力和横向力;然后计算出脱轨系数和轮重减载率,测试轨头位移,计算出轨距弹性挤开量。根据试验结果,对行车安全进行评估,同时全过程监控行车安全,为以后铁路便梁施工时提高列车限速、保证列车行车安全提供重要技术参数,具有重要意义。     

工厂安全性评价指标体系科学性的间接测定方法

工厂安全性评价指标体系是评价工厂安全性工作的测定标准，指标体系的科学性和合理性与工厂安全性评价工作密切相关。工厂安全性评价指标体系科学性的间接测定方法是，采用直接测定结果作为间接测定指标体系的样本，再利用各指标之间的相关量，求出间接测定结果，通过直接评价结果与间接评价结果的比较，检查直接评价结果的准确程度，以分析修正指标体系。     

IMPACT ASSESSMENT MODEL FOR CLEAR WATER FISHES EXPOSED TO EXCESSIVELY CLOUDY WATER1

ABSTRACT: A new type of empirical model described here enables real time assessment of impacts caused by excessive water cloudiness as a function of (a) reduced visual clarity (excessive cloudiness) and (b) duration of exposure to cloudy conditions, in fisheries or fish life stages adapted to life in clear water ecosystems. This model takes the familiar form used in earlier suspended sediment dose effect models where z is severity of ill effect (SEV), x is duration of exposure (h), y is black disk sighting range (y BD, m)—a measure of water clarity, a is the intercept, and b and c are slope coefficients. As calibrated in this study the model is Severity of ill effect is ranked on a 15‐step scale that ranges from 0 to 14, where zero represents nil effect and 14 represents 100 percent mortality. This model, based on peer consultation and limited meta analysis of peer reviewed reports, accomplishes the following: (a) identifies the threshold of the onset of ill effects among clear water fishes; (b) postulates the rate at which serious ill effects are likely to escalate as a function of reduced visual clarity and persistence; (c) provides a context (the “visual clarity” matrix, with its cell coordinates) to share and compare information about impacts as a function of visual clarity “climate” (d) demonstrates changes in predator prey interactions at exposures greater than and less than the threshold of direct ill effects; (e) calibrates trout reactive distance (cm) as function of water clarity in the form where y represents reactive distance (cm) and x represents visual clarity (black disk sighting range, cm), and where a and b are intercept and slope respectively, such that (f) identifies black disk sighting range, in meters, and its reciprocal, beam attenuation, as preferred monitoring variables; and (g) provides two additional optical quality variables (Secchi disk extinction distance and turbidity) which, suitably calibrated as they have been in this study, expand the range of monitoring options in situations in which the preferred technology—beam attenuation equipment or black disk sighting equipment—is unavailable or impractical to use. This new model demonstrates the efficacy of peer collaboration and defines new research horizons for its refinement.     

圆形烟道断面烟气测试中采样点距烟道内壁的距离讨论

本文根据圆形烟道采样点划分原则，给出了一种方便适用的采样点距烟道内壁的距离公式，并就现有文献中采样点距烟壁的距离值表格的误差进行了修正。     

石灰生产项目环评中应注意的几个问题

以燃煤石灰立窑为例主要从产业政策相符性分析、污染物产生量及产生浓度的计算、污染防治措施、卫生防护距离设置等方面论述石灰生产项目环评中应注意的几个问题,以供此类环评项目参考。