原子荧光光谱法测定土壤中痕量汞

建立微波消解土壤,原子荧光光谱法测定土壤中痕量汞的方法。方法检出限为0.018μg/g,加标回收率为95.0%~103.7%。本方法前处理操作过程简单、酸用量少,微波消解能使样品消解完全,可满足环境监测分析的要求。     

热分解齐化原子吸收光度法测定土壤中汞的研究

汞元素具有很强的毒害性,是一项需要重点检验的元素。采用固体进样热解金汞齐化原子吸收光度法,样品不需要消解即可直接测定土壤中汞的含量。在优化的实验条件下,仪器响应稳定;曲线状态良好(r=0.999),检出限0.009mg/kg;测试结果准确,质控土样相对误差0.6%~2.9%,加标回收率95.7%~96.8%。该方法具有简便、快速、准确、干扰少等优点,适宜于土壤中汞的实验室测试分析及环境应急快速检测分析。     

吹扫捕集-气相色谱法测定某农药厂废水中苯系物

采用吹扫捕集-气相色谱法测定某农药厂废水中苯系物,方法的相关系数r＞0.995,苯的相对偏差在0.9％～2.8％、甲苯的相对偏差在1.2％～1.8％,二甲苯的相对标准偏差在1.0％～2.0％;三种目标污染物的低浓度加标回收率在90.0％～96.0％,高浓度的加标回收率在89.0％～93.0％.结果表明相关系数、精密度、准确度均满足实验要求,可以应用于实际样品的测定.     

原子荧光法测量城市污泥中汞的研究

重金属汞的残留是城市污水厂污泥处理的一个重要问题。原子荧光光谱法是测定微量汞元素最有效的分析方法之一。微波消解法能较成功的解决污泥前处理问题,原子荧光光谱法(AFS)检出限为0.02μg/L,相对标准偏差为1.2%,加标回收率为86.5%~96.5%,适用于污泥的重金属分析与研究。     

三种消解方法用ICP-MS测定土壤中钒、钴的比较

在土壤样品的检测中,前处理和仪器条件对于检测结果有极其重要的影响,通过实验,比较了三种不同消解方法用ICP-MS测定土壤中钴、钒两种元素时的准确度、精密度,以及加标回收率数据,以及消解过程的复杂程度,便于检测人员选择合适的消解方法进行测定     

水浴消解和微波消解原子荧光法测定土壤重金属汞参加环保部测量审核样品的比对分析

通过水浴消解与微波消解2种前处理方法的对比实验,使用原子荧光法测定土壤中重金属汞含量的实验。参加环保部组织的测量审核,运用水浴消解与微波消解2种前处理方法的处理样品,2种方法的测试结果没有显著差异,能力评价满意。     

600MW燃煤电站烟气汞形态转化影响因素分析

燃煤电站汞排放是自然界人为汞排放的最大污染源,所以进行燃煤电站不同形态汞排放浓度的现场测试对了解和控制汞排放的规律有重要意义.采用国际上通用的Ontario Hydro方法对桌600MW燃煤电站ESP前、后的烟气进行采样,应用美国EPA标准方法测定了烟气中Hg0、Hg2 和HgP的浓度,应用DMA80测定固体样品(煤、底灰、ESP飞灰)中的汞浓度.测试结果表明:烟气经过ESP前后,烟气中汞形态发生了显著变化,Hg2 的比例由14.71％变为39.54％,Hg0由85.19％变为60.38％,HgP由0.10％变为0.08％.煤中的氯.烟气中的NOx、SO2、HCl和Cl2对烟气中氧化态汞的形成呈正相关.     

氢化物发生—原子荧光法测定沼液中砷的含量

采用氢化物发生—原子荧光法测定沼液中砷的含量,研究不同消解体系对测定结果的影响。采用不同的消解体系消解不同发酵程度的沼液样品,建立了不同沼液中砷的适宜分析条件。该方法检测限为0.051μg/L,回收率为97.5%~103.2%,结果令人满意。     

石墨炉原子吸收光谱法测定水中铅能力验证的体会

依据石墨炉原子吸收光谱法,对2015年度某市质监局能力验证考核样品水中铅含量进行测定,测定过程全程质量控制,取得了满意结果。探讨测定过程中应注意的试剂空白,调整仪器最佳状态,及加标回收实验等问题。     

静电除尘器对燃煤电站汞排放的影响

用自行设计的燃煤烟气汞形态测量装置在燃煤电站锅炉上进行了静电除尘器对汞排放影响的实验研究,得出如下结论:静电除尘器对汞的控制有一定的作用,除尘器后烟气中汞的含量明显低于除尘器前;烟气经过除尘器后汞的形态分布变化较大,除尘器后烟气中氧化态汞的含量大大降低,排放烟气中的汞主要为单质态汞;经过除尘器后氧化态的汞主要富集在飞灰中,单质态汞主要存在于烟气中,灰渣中汞的含量很低.研究结果可以对电厂燃煤烟气中汞迁移反应机理的理解和控制方法的设计提供有益的参考.     

黏土矿物在电池领域的应用研究进展

黏土矿物是一类含水硅酸盐矿物,主要含铝、镁等元素,在我国储量丰富、价格低廉。基于其晶体结构、微观形态和物化特性,黏土矿物可用于制备电池材料,改善电池性能。本文简述了凹凸棒石(坡缕石)、海泡石、蒙脱石等黏土矿物在电池电解质、电极材料中的研究进展,对存在的问题进行了分析,为下一步的研究提出了建议。     

叶片动应力计算的重要改进及其在不调频叶片设计上的应用

叶栅流场中的叶片受流道中汽流力的作用，同时也承受了流道中谐波汽流力的激振。由于谐波汽流力沿周向波动，其对叶片的激振力应该是流道宽度内谐波激振力的积分。本着这一观念对ASME早期发表的动应力基本方程进行改进，重新作了推导，并指出了降低叶片共振应力的途径。多年来已取得了成功应用，其中涉及带冠单叶片的动强度特性及不调频叶片事故处理的材料综合抗振强度对比分析，对工程实践具有一定的参考借鉴的价值。     

Impact of the price of energy on the use of conservation tillage in agriculture in the USA

The relationship between energy expenditure and the use of conservation tillage is of special importance in addressing concerns about the impact of agricultural production on the environment in the US. After establishing that a relationship exists between the price of energy and the use of conservation tillage via the Granger causality, the relationship is quantified. It is shown that while the real price of crude oil, the proxy used for the price of energy, does not affect the rate of adoption of conservation tillage, it does impact upon the extent to which it is used. Finally, there is no structural instability in the relationship between the relative use of conservation tillage and the real price of crude oil over the period 1963–1997.     

Efficiency of destruction of waste used in the co-incineration in the rotary kilns

This work presents a study about the efficiency of destruction of industrial waste, used in the co-incineration in rotary kilns of the cement industry, considering the principle of the chemistry equilibrium and the kinetic of the reactions. As an example, it has analysed the burn of one hazardous waste which has in its composition toluene, xylene and dicloroethane. The temperatures of the transformation and the time of the reaction to the formation of sub-products which will originate CO₂, H₂O and HCl, are evaluated. Thus, the formation of the pollutants in the kiln is preliminary estimated and the different forms to control the emissions is also discussed.     

数值模拟在凝汽器水侧流动特性分析中的应用

通过计算流体力学在实际工程中的分析和结果,详细阐述数值分析模拟在凝汽器水侧流动特性分析中的应用情况。通过对凝汽器水侧阻力进行计算和分析过程的详细剖析,阐述了数值模拟在水室结构优化,降低流动阻力等方面所起到的指导作用。     

Perspectives of solar cooling in view of the developments in the air-conditioning sector

Changes in the standards of thermal comfort in the urban microclimate and in the capital cost of air-conditioning equipment have drastically increased the energy consumption in the building sector over the last decade. At the same time, the integration of renewable energy systems, mainly active solar ones, in buildings has been an area of intense research over the last 30 years. This has also been the case in the field of solar refrigeration, mainly in the field of sorption systems. The analysis discussed in the paper is focused on the state of the art of thermal solar systems use and on the possibilities of combining those with state of the art technologies in sorption refrigeration, in order to cover the cooling demand of residential and commercial buildings. This was done by assessing the available solar and refrigeration technologies as well as by highlighting the situation in the building market, as this is still the dominant factor for the propagation of such systems.     

冠状动脉导丝、球囊技术在左锁骨下动脉闭塞介入治疗中的应用

【摘要】 目的 探讨冠状动脉导丝、球囊技术在左锁骨下动脉闭塞介入治疗中的应用。方法 采用冠状动脉导丝、球囊技术行血管内支架成形治疗11例左锁骨下动脉闭塞患者。结果 冠状动脉导丝、球囊技术血管内支架成形治疗锁骨下动脉闭塞患者,手术成功率高,10例左锁骨下动脉血流完全通畅,椎动脉正向血流方向恢复;局部并发症少。结论 冠状动脉导丝、球囊技术治疗锁骨下动脉闭塞患者效果可靠,操作相对简单、安全,并发症少。

     

Modelling of Heat Transfer in the Evaporator and Condenser of the Working Fluid in the Heat Pipe

The aim of this paper is to point out possible solutions to the further development of heat pipes by numerical modelling of phase-change heat transfer. Numerical modelling has now become a standard method that helps to reduce the economic costs of research and development of new and innovative devices. The article describes the procedures for using numerical simulation in phase-change heat transfer that occurs due to evaporation and condensation of the working fluid. The suggested procedure enables modelling of gravitational heat pipe under different changes in its geometry or under changes in the working fluid. From the simulation results we can find out how the heat pipe behaves under different geometric changes and how much heat output it transfers. The paper presents results obtained from modelling of heat pipes, such as classical gravitational heat pipe, heat pipe with capillary geometry, and closed loop pulsating heat pipe. The results gathered from numerical simulation of heat pipes were compared with measurement results.     

某舰主锅炉筒身内壁裂缝起因分析

本文介绍某舰中修时发现锅炉汽水联箱水部筒壁及锅炉汽筒产生裂缝情况。分析了产生这种情况的原因,主要是由腐蚀性疲劳和腐蚀性热应力所致。并对此提出一些合理化建议,供有关人员参考。     

Misconceptions in the application of the Sieverts technique

The Sieverts technique is commonly used for determining gas uptake, particularly for hydrogen storage material characterisation. Despite a considerable literature on correct technique, best practice and sources of potential errors, there is still confusion concerning application of this technique. We address three aspects of the Sieverts technique, (thermal transpiration, volume calibration and the effect of valve volume) in the context of a recent publication.