纳米尺度传热技术进展

本文主要概述了纳米尺度传热技术的研究进展,描述了纳米技术在导热、对流、以及辐射换热中的应用机理．分析了纳米尺度导热系数的计算方法和导热方程模型的建立．预测了纳米尺度传热技术在各个领域的应用和发展前景。     

Evaluation of non-point source pollution reduction by applying Best Management Practices using a SWAT model and QuickBird high resolution satellite imagery

This study evaluated the reduction e ect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km2 small agricultural watershed using a SWAT (Soil andWater Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using daily streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcli e model e ciency was 0.63 for the streamflow and the coe cients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian bu er system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.     

Impacts of soil organic matter, pH and exogenous copper on sorption behavior of norfloxacin in three soils

Norfloxacin (Nor) sorption and the factors (soil organic matter (SOM), pH, and exogenous copper (Cu) influencing the sorption were investigated in a black soil (soil B), a fluvo-aquic soil (soil F), and a red soil (soil R). With increasing of Nor concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity in SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum KD and KOC were achieved in soil R when the equilibrium solution pH was 6. And the norfloxacin sorption was also influenced by the exogenous Cu2+ ions, which depended on the soil types and Cu2+ concentrations. With increasing of Cu2+ concentrations in solution, generally, sorption amount, KD and KOC for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu2+, and then the sorption amount decreased regardless of norfloxacin levels.     

pH对Cd~(2+)离子在δ-MnO_2上的吸附与解吸的影响

研究了pH值对δ-MnO2对模拟废水中Cd2+的吸附作用的影响,当pH<2.3时,吸附率仅为20%,pH>5时Cd2+的吸附率在96%以上;吸附过程为非特性吸附,可以用Elovich方程和双速率方程来描述。吸附后δ-MnO2在pH<2.05时可以有效的解吸,解吸率约为75%。     

基于SEM的船员不安全行为研究

为研究船员不安全行为对船舶事故的影响程度,选取环境、身心状况等作为人不安全行为的影响因素,建立假设关系,运用结构方程(SEM)构建因素之间的关系模型,计算各变量之间的作用效应值.结果 表明:环境因素中工作氛围、工作设备和工作环境对不安全行为的减少有正向影响,但工作氛围产生的效应更明显;身心状态中心理因素和生理因素对不安全行为的减少有正向影响,两个因素对不安全行为产生的效应接近;工作环境和工作氛围通过影响船员的身心状态间接影响船员的不安全行为.船员的不安全行为影响因素对于船员管理起到重要作用,对增进船舶的安全具有重要意义.     

Removal of bentazone from micro-polluted water using MIEX resin: Kinetics, equilibrium, and mechanism

The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the e ect of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal e ciency of bentazone. Results showed the sorption process was fast and bentazone could be e ciently removed in 30 minutes. The kinetic process of bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle di usion was the rate controlling step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting. Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the sorption characteristics on MIEX resin. The di erent removal e ciencies of ionic and non-ionic pesticides, combined with the charge balance equations of bentazone, SO4 2??, NO3?? and Cl??, indicated that removal of bentazone using MIEX resin occurred primarily via ion exchange.     

多介质潜流人工湿地的水动力过程模拟

水动力过程是湿地净化功能发挥的重要机制之一.根据脉冲示踪试验,获得潜流人工湿地的水力停留时间分布曲线.针对其"多峰"现象,利用数学软件MATLAB7.0分别将对数正态分布、对流扩散模型以及考虑延迟的连续完全混合反应器模型时脉冲示踪试验数据进行叠加模拟,同时利用多流弥散模型拟合分析,结果表明:叠加模型和多流弥散模型均能较...     

风电“领跑”新能源

风能“点风成金”风是地球上的一种自然现象,它是由太阳辐射热引起的。太阳照射到地球表面,地球表面各处受热不同,产生温差,从而引起大气的对流运动形成风。风能是指地球表面大量空气流动所产生的动能。由于地面各处受太阳辐照后气温变化不同和空气中水蒸汽的含量不同,     

原油加热炉对流炉管表面积灰清理技术的应用

针对鲁宁线和中洛线原油加热炉炉管穿孔现象,对加热炉积灰成分、性质及成因进行了分析,提出有效的高压蒸汽清灰技术。现场应用表明,该技术可提高炉管换热效率、减少炉管的腐蚀,确保加热炉的安全运行。     

吸附质污染物输运研究

对含沙水体中的吸附质污染物输运过程进行分析,从单元体出发推导考虑泥沙影响的污染物输运方程。导出的方程考虑了冲刷沉降、孔隙水扩散和孔隙水混合作用的影响,并应用于灌河口的TP浓度计算,验证结果较好。