超高强度钢无氰镀镉-钛层在循环湿热试验条件下的腐蚀变化规律研究

目的研究超高强度钢表面无氰镀镉-钛层在循环湿热条件下的腐蚀变化规律。方法对超高强度钢表面无氰镀镉-钛层试样进行循环湿热试验,对各个加速时间段的试样进行宏观照片及微观照片的拍摄,并运用电化学测试分析的方法研究试样在加速试验各时间段的腐蚀变化规律。结果超高强度钢表面无氰镀镉-钛层经历384 h的循环湿热试验后,镀层首先开始出现腐蚀现象。试样的腐蚀失质量损失随试验时间的延长逐渐增加,且呈现出在试验初期(≤384 h)的增量相对较小,试验中后期(384 h)的增量相对较大的特征,腐蚀动力学方程和曲线的特征也表明,试样在循环湿热试验后期的腐蚀速率相对较大。经历1536 h循环湿热试验的试样在0.01 Hz处的阻抗模值下降为10~2?。结论循环湿热条件下,在加速试验初期,超高强度钢表面无氰镀镉-钛层试样表面镀层开始发生腐蚀,中期腐蚀现象减缓,后期腐蚀现象明显。质量损失数据与试验时间关系的幂函数拟合方程为D(t)=0.013t~(1.2095),相关指数R~2=0.9879。     

The Importance of Leaching from Litter Collected in Litterfall Traps

Litterfall (LF) is usually collected by means of opentraps. However, this litter will be subject toleaching by the throughfall which passes through theaccumulated litter in the traps. The nutrients lostduring this leaching are not taken into account in thecalculation of LF nutrient fluxes. We report theresults from a 2-month (August–September) studycarried out in 8 northern coniferous forest stands toassess the possible importance of leaching from litterin LF traps. Compared to throughfall (TF), thelitterfall leachate (LFL_gross), which includes athroughfall component, had significantly (p < 0.05)higher concentrations and fluxes of Ca, Mg, Na and S.The average net LFL (i.e., LFL_net = LFL_gross-TF) fluxes were 21 (Ca), 7 (Mg), 57 (K), 10 (Na), 10 (N), and 19 (S) mg m^-2 mo^-1. LFL_net accounted for 42%, 37% and 50% of the LFL_gross flux, and for 91%, 51% and 49% of the total litterfall flux (i.e.,LF + LFL_net) of Na, S and K, respectively. ForCa, Mg and N, the LFL_net flux accounted for 64%,58% and 29% of the LFL_gross flux, and for< 14% of the total litterfall flux. Compared to TF,LF was the dominant return pathway for Ca, Mg and N tothe forest floor regardless of whether LFL_net wasincluded or not. However, for K and S, takingLFL_net into account determined whether TF or LFwas the dominant pathway. TF remained the dominantpathway for Na even when LFL_net was included.     

RESEARCH: Issues Related to Greenhouse Effect,Productivity Modeling,and Nutrient Cycling: A Case Study of Indian Wetlands

/ Models available in the literature on nutrient uptake, lightavailability, and chlorophyll growth have been suitably modified andintegrated through the computer program CHLORF (written in "C"language), which has the advantage of being amenable to simulation undervarious combinations of input variables. The model has been used forsensitivity analysis in order to identify the most sensitive set ofparameters whose control can form an appropriate basis for evolving pragmaticmanagement strategies. In addition, greenhouse mitigation potential has beencomputed in terms of assimilation of carbon dioxide for a case study ofIndian wetlands.KEY WORDS: Wetland; Nutrient cycling; Modeling; Greenhouse effect     

废铁屑处理难生物降解染料废水

研究了用废铁屑处理难生物降解的染料废水，考察了进pH值、曝气时间、固液比、铁屑粒度对废水处理效果的影响，并确定了适宜实验条件。实验证明，该法可以有效去除染料废水的色度和CODcr，在实验考察范围内，脱色率和CODcr去除率分别可达90％、61.7%。同时废水可生化性也得到了改善，BOD5／CODcr从19.6%上升到29.5%，提高了50％,有利于后续生化处理。该法以废治废，是一种很有实用价值的废水处理方法。     

生活垃圾处理与资源化利用分析

垃圾产生量与人口和GDP有直接的关系，针对目前城市生活垃圾的现状和特点，分析了垃圾产生量与人口增长的规律。简要介绍了几种主要的垃圾处理方法，分析探讨了城市生活垃圾处理处置技术和发展趋势。     

在矿山开发环评中的生态保护问题探讨--以蒙库露天铁矿山开发环评为例

在分析蒙库铁矿山露天开采可能造成的生态影响基础上，讨论矿山开采各个环节对生态因子的影响及强度，筛选出主要影响因子。提出相应的生态环境保护对策。     

Nutrient cycling characteristics of Quercus acutissima and Pinus massoniana mixed forest in the Three-Gorge Reservoir area, China

The cycling characteristics of nitrogen(N), phosphorus(P) and potassium(K) of the Quercus acutissima and Pinus massoniana mixed forest, which is the most common forest type in the Three Gorge Reservoir areas in China, were systematically analyzed. The results showed that N, P and K accumulated in the plant pool and in the litter pool, while total N, P, and K were deficient in the soil pool and in the forest systems. Contents of N in the soil of depth 20-40 cm were the key factor limiting growth of trees. The biological outside cycling coefficients were 8.78, 72.5 and 11.7 times of inside cycling coefficients of N, P and K, respectively. 33.92, 10.26 and 15.88 kg of N, P and K return to the litter pool from branches, leaves and throughfall per year, but, 14.31, 1.32 and 10.48 kg of N, P and K return to the soil from litter pool per year respectively. It is clear that 58% of N, 87% of P, and 34% of K are lost by surface runoff per year. 5.49%, 1.30%, and 8.34% of N, P and K withdraw from leaves to branches, 4.99%, 1.99% and 7.30% of N, P and K withdraw from branches to trunks per year,respectively.     

氧化铁系脱硫剂在移动床中脱除SO2的实验研究

分析了移动床和固定床吸附特性，认为移动床具有床层利用率高，空速大，可连续的优点，由实验确定了移动床适宜空速和固体物料流量。经１０３９小时运行，证实移动床的脱硫率，硫容均令人满意，床层利用率可达９５％。     

内循环三相流化床流体动力学性质的初步研究

研究了内循环三相流化床流体动力学的一些性质，认为随着进气流量的增大，氧的体积传递系数、气含率增加，混合时间与循环时间则减小。而随着载体的加入量增大，气含率、氧传递系数、循环时间和混合时间均有减小的趋势。根据实验结果确定载体投加量为6％，相应的进气量控制在0．75－1Nm^3/h之间。     

地热水除铁除锰工艺研究

通过对地热水的特点及其用途的分析 ,阐述了地热水除铁除锰机理 ,采用曝气充氧、天然锰砂接触氧化的除铁除锰工艺 ,并适当控制反冲洗强度和时间 ,使处理后地热水含铁、锰浓度达到标准 ,且不增加有害成分或减少有益成分。设备投资省、运行成本低 ,热损失小 ,是一种理想的地热水除铁工艺。