火场中新型铜包铝导线熔痕的金相鉴别研究

选用合格多股的铜包铝导线和劣质的单股铜包铝导线制备一次、二次短路熔痕和火烧熔痕,以金相法为基础,采用常用的三种浸蚀剂研究该种导线熔痕的浸蚀方法,观察每种熔痕的金相组织晶粒和气孔特征。分析发现:HF浸蚀剂浸蚀效果最好,一次短路熔痕、二次短路熔痕和火烧熔痕的金相组织呈现出了有别于铜、铝导线熔痕的特征。区别于铜包铝导线二次短路熔痕,一次短路熔痕的金相组织最显著的特征是晶粒以细小的胞状晶、柱状晶为主,且组织中气孔数量相对较少。二次短路熔痕多数晶粒为粗大的胞状晶和柱状晶,存在大气孔,且分割晶界。与铜、铝导线火烧熔痕不同,铜包铝导线火烧熔痕的晶粒不以等轴晶为主。     

加热时间对铜导线二次短路熔珠微观形貌的影响分析

为考查加热不同时间铜导线二次短路熔珠微观形貌的变化规律,本文利用扫描电子显微镜对在一定温度下加热不同时间的铜导线二次短路熔珠进行了观察,并分析了加热时间对铜导线二次短路熔珠微观形貌的影响。实验结果显示,随着加热时间的增加,铜导线二次短路熔珠断面上的孔洞增加、晶界变得不明显、结晶颗粒增多。     

铜铝导线违规搭接的火灾危险性研究

研究了铜铝导线在违规搭接状态下的火灾危险性,选用常见的线径为2.5 mm2的铜铝导线,模拟出在实际生活中可能出现的铜铝导线违规搭接状态。具体阐述了实验仪器、材料和过程。实验结果表明:铜铝导线的违规搭接会在接点处形成较大的接触电阻,在电流作用下接触点温度上升,进一步增大接触电阻,形成恶性循环,具有较大的火灾危险性。     

多股铜导线一次短路熔痕金相定量分析

模拟火灾现场形式,利用火灾痕迹物证综合试验台,制备多股铜导线的一次短路熔痕,设计自然冷却、水激冷却等不同冷却环境,通过金相显微镜观察其金相组织,同时,进行10次同条件实验,进行横向比较,判断金相显微组织呈现出来的稳定性,利用IPP图像分析软件,对实验采集结果进行定量分析,归纳金相组织的量化指标.实验结果表明,火灾现场电器元件短路时间、火场温度、导线冷却方式均可对多股铜导线的一次短路所形成的短路熔痕金相显微组织的微观形态产生一定影响.通过横向比较分析实验数据,进行数学建模归纳运算,排除干扰因素条件,得到的多组实验数据的金相显微组织形态具有极其一致的相似性和稳定性.     

铜导线熔痕组织结构特征的分析研究

通过对火灾中铜导线熔痕的组织结构进行X射线衍射仪分析,找出了铜导线一次短路熔痕、二次短路熔痕、火烧熔痕在物相组成、晶面取向和晶格畸变等参数的特征规律,建立了铜导线熔痕组织特征的技术鉴定方法,为火灾物证鉴定提供定量技术依据。     

铜导线搭铁短路熔痕表面组成成分分析

对单芯聚氯乙烯铜导线搭铁短路故障进行模拟实验,记录火灾前和火灾中搭铁短路形成的铜导线熔痕表面组成成分随着电流增大而改变的情况,并分析其原因。通过线性回归分析讨论铜导线熔痕表面不同元素含量的影响因素。研究可为火灾事故调查工作提供科学的指导。     

铜导线搭铁短路熔痕金相组织特征分析

搭铁短路作为一种特殊的短路故障,在电气火灾痕迹物证鉴定工作中难度较大。通过对单芯聚氯乙烯铜导线火灾前搭铁短路故障进行模拟实验,对其形成的铜导线熔痕金相组织特征进行全面的技术鉴定与分析,并与火灾前线间短路熔痕金相组织特征进行对比,为火灾事故调查工作提供科学的指导。     

火场中铝合金导线熔痕的定量金相分析

借助计算机图像处理技术和金相分析技术对铝合金导线短路及火烧熔痕的晶粒与气孔的特点进行定性与定量分析,并依次与相同条件下铝导线熔痕金相组织特征对比。结果表明：铝合金导线一次、二次短路熔痕及火烧熔痕在晶粒、气孔的大小、形状等方面的几何参数有一定的差异,且与同条件铝导线熔痕在晶粒面积、气孔分布上也有差异。     

SEM和EDS分析铜导线短路熔痕晶粒特征

通过定性模拟实验,制备交流220 V电路中铜导线一次短路熔痕和二次短路熔痕,应用SEM和EDS等方法研究铜导线一次短路熔痕与二次短路熔痕外表面晶粒的微观形貌特征以及化学元素变化规律。结果表明,短路方式是铜导线短路熔痕晶粒形貌特征的决定因素。铜导线一次短路熔痕晶粒呈现胞状晶形貌特征,二次短路熔痕晶粒呈现柱状晶形貌特征,熔痕凝固及火灾过程中形成的氧化膜不会影响熔痕晶粒形貌特征。     

多股铜导线二次短路熔珠形貌特征的SEM分析

为考查不同火场环境温度下二次短路熔珠表面的显微形貌,采用实验模拟火场热环境,对多股铜导线二次短路熔珠进行加热、腐蚀处理,利用扫描电镜分别观察加热、腐蚀前后铜导线熔珠表面形貌特征,得出相应的实验结果,并加以分析。     

铜塑铝板和纯铜板的生命周期评价

通过对铜塑铝板和纯铜板开展全生命周期环境影响分析,得出不可再生资源消耗和温室效应对环境的影响最为严重.铜塑铝板的环境性能明显优于纯铜板,单一环境影响降低90%.     

Determination of copper in water by means of chalcocite copper ion-selective electrode

The possibility of determination of copper in natural waters was tested by direct potentiometry with chalcocite copper sensitive ion selective electrode. This can be carried out for the copper concentration down to 6 μg l⁻¹ when the standard additions procedure is used. The electrode characteristics was investigated and as a medium was proposed a TFB solution containing Tris, potassium fluoride and potassium nitrate. However at the extreme low concentrations of copper the water samples after addition of TFB should be heated to boiling. In these conditions the accuracy of determination for the average of five measurements is not worse than 25%, and precision is of the order of 20%.     

Sensitivity of marine microalgae to copper: the effect of biotic factors on copper adsorption and toxicity

Microalgae are sensitive indicators of environmental change and, as the basis of most freshwater and marine ecosystems, are widely used in the assessment of risk and development of environmental regulations for metals. However, interspecies differences in sensitivity to metals are not well understood. The relationship between metal-algal cell binding and copper sensitivity of marine microalgae was investigated using a series of 72-h growth-rate inhibition bioassays and short-term (1-h) uptake studies. A range of marine algae from different taxonomic groups were screened to determine whether copper adsorption to the cell membrane was influenced by biotic factors, such as the ultrastructure of cell walls and cell size. Minutocellus polymorphus was the most sensitive species to copper and Dunaliella tertiolecta the least sensitive, with 72-h IC50 values (concentration to inhibit growth-rate by 50%) of 0.6 and 530 microg Cu/L, respectively. Copper solution-cell partition coefficients at equilibrium (K(d)) were calculated for six species of algae on a per cell and surface area basis. The largest and smallest cells had the lowest and highest K(d) values, respectively (on a surface area basis), with a general (non-linear) trend of decreasing K(d) with increasing cell surface area (p=0.026), however, no relationship was found between K(d) and copper sensitivity, nor cell size and copper sensitivity. Interspecies differences in copper sensitivity were not related to cell size, cell wall type, taxonomic group or K(d) values. The differences in sensitivity may be due to differences in uptake rates across the plasma membrane, in internal binding mechanisms and/or detoxification mechanisms between the different microalgal species.     

Characterization of copper bioreduction and biosorption by a highly copper resistant bacterium isolated from copper-contaminated vineyard soil

Copper is an essential but toxic heavy metal that negatively impacts living systems at high concentration. This study presents factors affecting copper bioremoval (bioreduction and biosorption) by a highly copper resistant monoculture of Pseudomonas sp. NA and copper bioremoval from soil. Seven bacteria resistant to high concentration of Cu(II) were isolated from enrichment cultures of vineyard soils and mining wastes. Culture parameters influencing copper bioreduction and biosorption by one monoculture isolate were studied. The isolate was identified by 16S rRNA gene sequence analysis as a Pseudomonas sp. NA (98% similarity to Pseudomonas putida, Pseudomonas plecoglossicida and other Pseudomonas sp.). The optimal temperature for growth was 30 °C and bioremoval of Cu(II) was maximal at 35 °C. Considerable growth of the isolate was observed between pH 5.0 and 8.0 with the highest growth and biosorption recorded at pH 6.0. Maximal bioreduction was observed at pH 5.0. Cu(II) bioremoval was directly proportional to Cu(II) concentration in media. Pseudomonas sp. NA removed more than 110 mg L^− 1 Cu(II) in water within 24 h through bioreduction and biosorption at initial concentration of 300 mg L^− 1. In cultures amended with 100 mg L^− 1, 20.7 mg L^− 1 of Cu(II) was biologically reduced and more than 23 mg L^− 1 of Cu(II) was biologically removed in 12 h. The isolate strongly promoted copper bioleaching in soil. Results indicate that Pseudomonas sp. NA has good potential as an agent for removing copper from water and soil.     

Distribution and bioavailability of copper in farm effluent

Effluent and sludge samples from a number of dairy and piggery units in the North Island of New Zealand were collected and analysed for free ionic-copper (Cu(2+)) and organically-complexed Cu. The bioavailability of sludge-Cu was examined using microbial respiration and plant growth experiments. Microbial respiration was measured at various levels of Cu (0-1000 mg kg(-1)), added as copper sulfate (CuSO(4)) and sludge-Cu, using a Gilson differential respirometer. A glass house experiment was conducted to examine the transformation of Cu in soils and its subsequent uptake by ryegrass pasture. Three Cu sources were used that included fast-release CuSO(4), slow-release copper oxide (CuO) and Cu-enriched sludge. The pasture samples were analysed for Cu concentration. The transformation of Cu in the soil was monitored by analysing the soil samples for various fractions of Cu. The effluent and sludge samples collected from farms which regularly used Cu to treat lameness in dairy cattle and as a growth promoter in swine contained higher concentration of Cu. The total Cu concentration ranged from approximately 0.1 to 1.55 mg l(-1) and from 0.5 to 10.5 mg l(-1) in the piggery and diary effluent, respectively. The corresponding values for the sludge samples were 3.0-526 and 25-105 mg kg(-1). Most of the Cu in both the effluent and solid sludge material was organically complexed. The respiration measurements indicated that sludge-Cu was less toxic to soil microbial activity than CuSO(4). The results from the glass house experiment indicated that increasing the level of Cu applied through fertilisers and sludge increased Cu concentration in plants. At the same rate of application, plants took up less Cu from sludge and CuO than from CuSO(4). There was, however, a greater translocation of Cu from root to shoot at the highest rate of Cu through sludge application. The Cu fractionation study indicated that there was greater accumulation of organic bound Cu in the sludge-treated soil than the fertiliser-treated soil.     

化学发光法测定铜的进展

概述了以鲁米诺、邻菲啉等为主要化学发光试剂 ,广泛应用于各种物料中测定微量铜的化学发光分析方法的进展 .分别叙述了用于测定微量铜的不同化学发光体系 ,发光试剂浓度 ,试剂溶液加入的先后顺序 ,以及不同介质溶液的选择等对体系化学发光强度的影响 .试验了表面活性剂对微量铜在化学发光体系中的敏化作用 ,同时研究了微量铜在化学发光体系中存在的不同形态对化学发光信号强弱的影响 .并且对以鲁米诺、邻菲啉为化学发光试剂在化学发光体系中的化学发光反应的机理进行了初步探讨     

铜管对流散热器的分析

针对对流散热器的工作特性,全面分析了铜管铝片对流散热器在实际工程中应用的优势,并提出应当重视和推进铜管对流散热器的开发应用。     

赞比亚中央省瑞娜铜矿区碳酸岩及其与成矿的关系

通过对赞比亚中央省瑞娜铜矿区钻孔岩芯的系统研究,作者认为该区的含矿围岩为典型的火成碳酸岩,详细的岩矿相学研究也揭示瑞娜铜矿为碳酸岩岩浆型铜矿床.岩浆发生液态不混溶作用,溶离出碱性硅酸盐熔体、金属硫化物熔体和挥发份(CO2、H2O、F、Cl、B、P等)等流体,岩浆所携带的碱质使接触带地层交代蚀变成霓长岩,挥发份以络合物的形式携带部分Cu、Au、Ag、Ga、Co、REE、Ni等金属元素在外接触带地层碎裂岩和内接触带处成矿.     

铜导线短路熔痕中氧化亚铜形成机理研究

以铜导线为研究对象，应用XRD 检测和热分析方法，分析了氧化亚铜的形成机理。得出在铜导线加热到800 ℃条件下，加热产物中氧化铜质量分数高达91.60%，而氧化亚铜质量分数仅有0.90%；在铜导线加热1 100 ℃条件下，加热产物中氧化亚铜质量分数增加，达到65.30%，氧化铜质量分数为34.70%。分析铜导线两种加热温度的TG 曲线，结合热力学原理，得到铜的两种氧化物之间的转化温度并比较了两者在不同温度下的稳定性，为火灾调查与事故鉴定提供参考。