遥感技术在环境监测中的作用

本文对遥感(3S)技术在环境监测中的应用方法、技术等进行了论述.     

地表水环境监测进展与问题分析

地表水环境的质量监测对我国水环境保护工作具有非常重要的作用,同时对我国的经济发展有着深远的影响。随着我国经济的快速发展,我国水环境监测工作有了较大的发展,但是在仪器更新、分析能力等方面还存在一系列的问题,本文对地表水环境监测的进展进行了阐述,并分析了水环境监测中存在的问题。     

金鱼对镉的吸收研究

用原子吸收分光光度法研究镉在鲫鱼体内积累行为,结果表明,溶解态镉在鱼鳃和肌肉的积累,可分别用模拟方程：Y＝0．9214ln（x）-0．1173（鱼鳃）、Y＝0．3641ln（x）-0．1091（肌肉）来表示。鱼对镉有很强的蓄积能力,刚接触时蓄积速度比较快,之后逐渐减慢,以至达到动态平衡。     

谈清洁生产促进高耗能企业节能减排

本文通过对高纯硅铁生产企业清洁生产审核实例废热烟气发电项目的分析。为生产硅铁的高耗能企业烟气余热利用提供了技术保证。为下一步在高耗能企业中推广节能减排废气综合利用提供理论基础。     

内蒙古畜禽养殖及污染防治现状初步分析

本文在分析内蒙古五类畜禽的养殖总量、养殖区域特点及其污染物排放总量的基础上,初步分析内蒙古目前的养殖业现状,进一步分析判断现有存在的问题.为寻求解决内蒙古畜禽养殖污染防治最佳方案,顺利完成畜禽养殖业污染物减排任务提供基础分析材料.     

乌海市污染源在线监控系统应用现状及对策研究

本文结合乌海市污染源在线监控系统的日常管理工作实践,分析总结了乌海市污染源在线监控系统的安装、运行管理现状及存在的问题与不足并提出了相应的对策及建议。     

内生菌在修复重金属污染土壤的研究进展

内生菌是生活于植物的各组织、器官内部,但并不使植物表现出有害症状的真菌、细菌或放线菌。因其具有固氮、矿物溶解、光合作用、载运铁、利用1－氨基环丙烷－1羧酸为唯一氮源、传递营养物质等作用,内生菌在修复重金属污染土壤方面具有重要应用潜力。本文综述了内生菌及其抗重金属机理（促进植物生长和拮抗重金属方面）研究进展,以期为修复重金属污染土壤提供新思路。     

巴丹吉林沙漠与库布齐沙漠植被现状调查

本文通过对巴丹吉林和库布齐两大沙漠的共计12个点位的植被调查显示,两大沙漠植被均以灌木建群,都伴生大量一年生沙生先锋植物;库布齐沙漠植物群落中,多年生草本物种数增加,是群落趋于稳定的表现;库布齐沙漠人工治理力度较大,使得群落生境趋优速度加快。巴丹吉林沙漠植物群落基本处于自然状态。     

Life cycle comparison of hydrothermal liquefaction and lipid extraction pathways to renewable diesel from algae

Algae biomass is an attractive biofuel feedstock when grown with high productivity on marginal land. Hydrothermal liquefaction (HTL) produces more oil from algae than lipid extraction (LE) does because protein and carbohydrates are converted, in part, to oil. Since nitrogen in the algae biomass is incorporated into the HTL oil, and since lipid extracted algae for generating heat and electricity are not co-produced by HTL, there are questions regarding implications for emissions and energy use. We studied the HTL and LE pathways for renewable diesel (RD) production by modeling all essential operations from nutrient manufacturing through fuel use. Our objective was to identify the key relationships affecting HTL energy consumption and emissions. LE, with identical upstream growth model and consistent hydroprocessing model, served as reference. HTL used 1.8 fold less algae than did LE but required 5.2 times more ammonia when nitrogen incorporated in the HTL oil was treated as lost. HTL RD had life cycle emissions of 31,000 gCO₂ equivalent (gCO₂e) compared to 21,500 gCO₂e for LE based RD per million BTU of RD produced. Greenhouse gas (GHG) emissions increased when yields exceeded 0.4 g HTL oil/g algae because insufficient carbon was left for biogas generation. Key variables in the analysis were the HTL oil yield, the hydrogen demand during upgrading, and the nitrogen content of the HTL oil. Future work requires better data for upgrading renewable oils to RD and requires consideration of nitrogen recycling during upgrading.     

Analytical model of metalworking fluid penetration into the flank contact zone in orthogonal cutting

Metalworking fluids (MWFs) are used widely in machining process to dissipate heat, lubricate moving surfaces, and clear chips. They have also been linked to a number of environmental and worker health problems. To reduce these impacts, minimum quantity lubrication (MQL) sprays of MWF delivered in air or CO₂ have been proposed. MQL sprays can achieve performance comparable with conventional water-based or straight oil MWFs while only delivering a small fraction of the fluid. This performance advantage could be explained by the enhanced penetration into the cutting zone that results from delivering MWF in high pressure and precise sprays. To explore this hypothesis, an analytical model of MWF penetration into the flank face of the cutting zone is developed and validated using experimental data. The model is based on a derivation of the Navier–Stokes equation and the Reynolds equation for lubrication and applied to an orthogonal cutting geometry under steady-state conditions. A solution to the model is obtained using a numerical strategy of discretizing the analytical scheme with two-dimensional centered finite difference method. Penetration into the cutting zone is estimated for MQL sprays delivered in air, CO₂ and N₂ as well as two conventional MWFs, straight oil and semi-synthetic emulsion. The model suggests that conventional MWFs, do not penetrate the cutting zone fully and fail to provide direct cooling to the flank zone where wear is most likely to occur. MQL sprays do penetrate the cutting zone completely. Using convective heat transfer coefficients from a previous study, a finite element heat balance is carried out on the tool to understand how each fluid impacts temperature near the flank tip of the tool. The results of the modeling effort are consistent with experimental measurements of tool temperature during turning of titanium (6AL4V) using a K313 carbide tool. The prediction of temperature near the flank indicates that MQL sprays do suppress temperatures near the flank effectively. These results help explain the low levels of tool wear observed for some MQL sprays, particularly those based on high pressure CO₂. This modeling framework provides valuable insight into how lubricant delivery characteristics such as speed, viscosity, and cutting zone geometry can impact lubricant penetration.