The importance of temperature in assessing iron pipe corrosion in water distribution systems

Temperature is expected to play a significant role in the corrosion of iron pipes in drinking water distribution systems. Temperature impacts many parameters that are critical to pipe corrosion including biological activity, physical properties of the solution, thermodynamic and physical properties of corrosion scale, and chemical rates. Moreover, variations in temperature and temperature gradients may give rise to new corrosion phenomena worthy of consideration by water treatment personnel.     

A Global Overview of Atmospheric Acid Deposition Fluxes

This paper presents a summary of globalacid deposition flux data taken from a globalassessment report on acid deposition prepared forUNEP/WMO (Whelpdale and Kaiser, 1996). There is a largevariation in the spacial coverage and reliability ofmonitoring around the world. Many more stationsmeasure wet deposition than collect appropriate datafor estimating dry deposition. The widespread regionswith highest precipitation concentrations anddeposition fluxes of sulphate and nitrate coincideclosely with the regions of highest density ofSO₂ and NO_x precursor emissions occurringprimarily in the mid-latitude, northern hemispherebelt where a large fraction of the worlds fossilfuels is consumed. Organic acids in precipitation makea minor contribution to acidity (<20%) inindustrial regions, but in the rest of the world theyare of same order, or even exceed, inorganic acids.Less is known about dry deposition, but it appears topredominate near strong emission sources with wetdeposition predominating farther downwind. The molarratio of the N/S contribution to acidic deposition isclose to 1.0 over large areas of Europe and NorthAmerica, but is highly variable elsewhere, beinghighest in equatorial regions due to biomass burningand lowest near smelters and other large sources of SO₂.     

A study on the orbit of air temperature movement

In this paper, we describe an air temperature movement by mapping its time series to the polar coordinates: the value of the time series is plotted on the radial coordinate and the time on the angular coordinate. In this way, both the yearly and daily air temperature movements from five different locations of China are used to demonstrate that, in an intuitionistic view, air temperature movement is neither random nor chaotic, but has its own orbit. We then propose an elliptic orbit model for the air temperature movement. Our proposed model provides quite good results when it is applied to the evaluation of yearly air temperature movements in eight locations in various parts of the world, and the evaluation of daily air temperature movements in five locations in Hunan Province of China on December 17, 2005. Results show that our approach provides a concise and helpful model for air temperature analysis.     

汽车尾气污染及其净化处理技术

本文详细阐述了汽车尾气的有害成份及其对人类健康的危害。为此 ,应该采取净化处理措施 ,减少或者消除有害气体的产生 ,为大气环境洁净而创造条件。     

Preparation of rare-earth metal complex oxide catalysts for catalytic wet air oxidation

Catalytic wet air oxidation (CWAO) is one of the most promising technologies for pollution abatement. Developing catalysts with high activity and stability is crucial for the application of the CWAO process. The Mn/Ce complex oxide catalysts for CWAO of high concentration phenol-containing wastewater were prepared by coprecipitation. The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis. The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller (BET) analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry (ICP-AES). The results show that the catalysts have high catalytic activities even at a low temperature (80°C) and low oxygen partial pressure (0.5 MPa) in a batch reactor. The metallic ion leaching is comparatively low (Mn<6.577 mg/L and Ce<0.6910 mg/L, respectively) in the CWAO process. The phenol, COD_Cr, and TOC removal efficiencies in the solution exceed 98.5% using the optimal catalyst (named CSP). The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater. Translated from Techniques and Equipment for Environmental Pollution Control, 2005, 6(2): 40–44 [译自: 环境污染治理技术与设备]     

曲面零件在拉深过程中内皱时刻及影响因素

进一步推导了曲面零件悬空区上的应力分布及临界失稳公式。然后通过计算机编程 ,求解了临界失稳方程 ,得到了拉深系数、相对锥顶半径、相对圆角半径、材料相对厚度与临界失稳时刻间的关系曲线 ,并对曲线变化的规律进行了分析。     

唐钢2×150t转炉煤气回收系统设计及运行实践

在此较详细地介绍了唐钢一炼钢厂 2× 15 0t转炉煤气回收湿法除尘工艺和系统的技术特点。该系统设计吸收了国内外大型转炉煤气回收的经验。经近 18个月的生产实践 ;认为效果良好 ,煤气回收率近 80 % ,热值近 80 0 0kJ Nm3,放散排放浓度小于 80mg m     

连续速度场解析圆管辊拔减径

此文利用连续速度场解析了圆管辊拔减径问题的拔制力,并获得上界解析解.该解与圆管辊拔实验结果比较表明,两者吻合较好.因而,该解析解可在工程上计算圆管辊拔拔制力时推广应用.     

湿式脱硫除尘技术在开发应用中的几点看法

当前,随着经济的快速发展,全国燃煤量不断增加,二氧化硫、烟尘超标排放已导致严重的环境污染问题.二氧化硫、烟尘排放量的控制,可采用选用清洁煤,改变燃烧技术及末尾脱硫除尘技术.比较而言,烟气除尘脱硫技术是一种技术成熟较为经济的应用技术.其中湿式脱硫除尘技术已得到广泛推广与应用,但该技术中仍存在不能消除黑烟、二氧化硫脱除不稳定因素多、设备腐蚀问题.本文通过对实际测试结果分析及脱硫效率影响因素的分析,提出了相应的看法与建议.     

燃煤锅炉氨法烟气脱硫

通过氨法脱硫工艺在75t燃煤锅炉烟气脱硫工程中的运用,阐述了氨法脱硫的原理及工业条件,并对运行指标及处理效果进行分析。