离子选择电极法测定土壤全氟化物熔融条件的控制

离子选择电极法测定土壤全氟化物前处理过程中的熔融条件控制至关重要。使用马弗炉或高温烘箱直接升温,熔融反应过于剧烈,测定结果误差大。本实验就氢氧化钠与土壤的比例、马弗炉的升温方式、熔融最终温度和时间的选择进行相关研究。通过实际样品和有证标准样品多次试验验证：本方法检出限为12.5mg/kg;平行测定的相对标准偏差RSD=2.0%-5.9%;有证标准样品测定结果与真值的相对误差RE%=-1.1%-1.3%。程序升温控制熔融条件下,样品测定的准确、可靠性得到了改善。

微波等离子体用于消除温室气体全氟化物的研究进展

根据文献报道,评述了1997-2009年以来微波等离子体用于消除温室气体全氟化物的研究进展。介绍了几类微波等离子体系统,包括放电管型微波等离子体、微波等离子体共振腔反应器、炬型微波等离子体等(引用文献31篇)。

温室气体SF_(6)和CF_(4)的大气压微波等离子体降解技术

全氟化物气体(PFCs)中典型的温室气体SF_(6)和CF_(4)在环境中的排放从长远来看对大气温室效应的影响非常大。大气压微波等离子体炬的稳定放电状态提供了适合于气相化学反应的等离子体环境。为此利用大气压微波等离子体炬对SF_(6)和CF_(4)的分解和转化进行了研究,考察了通过傅立叶红外吸收光谱(FTIR)定量测量的去除率(destruction and remove efficiency,DRE)随着微波功率、气体体积流量、混合体积分数、反应室的结构等外部控制参数的变化规律。实验表明:通过增加优化化学反应缓冲室的结构参数和设置合适的工作条件可以使两者的去除率接近100%。因此,利用大气压微波等离子体炬针对一些实际工况下SF_(6)和CF_(4)的排放是能够有效控制的,例如,基于大气压微波等离子体技术的车载移动式处理设备,对降解和处理电力工业排放的SF_(6)给出了一种解决方案;采用管线末端处理方式,大气压微波等离子体炬应用于降解半导体工业排放的CF_(4)等尾气是一种具有应用前景的技术。

PECVD制程中C_3F_8替代C_2F_6的研究

研究表明含氟气体的性质决定了原子氟(F)的转化效率,通常在CxFy气体中x的值越大,氟(F)的转化效率也就会越高。所以C3F8(八氟丙烷)比C2F6(乙氟烷)具有更高的利用效率,更少的PFC(全氟化物)的排放。文章主要研究在以四乙氧基硅烷(TOES)为基础的离子增强化学气相沉积(Plasma Enhanced Chemical Vapor Deposition,PECVD)的清洗制程中,利用分解效率高的C3F8气体取代C2F6气体。通过实验设计(Design Of Experiment,DOE),调整腔体压力、射频(RF)功率、气体流量等参数,最终得到最优化的新清洗配方。应用到实际的量产中,有效地降低了成本,减少了PFC的排放。

专利文摘

一种染料废水的处理方法及设备，一种硫资源综合利用的烟气净化工艺，炼油废碱液处理方法，1，4-二羟基蒽醌生产废水的回收方法，全氟化物废气处理方法，一种废水深度净化处理方法。

国内外集成电路制造业PFCs排放量计算方法的对比研究

全氟化物(PFCs)是《京都议定书》确定的6种温室气体之一,大多数PFCs具有极高的全球暖化潜势值,在集成电路制造过程中会排放大量的PFCs。通过分析目前国内外集成电路制造行业PFCs排放量的计算方法,对比了其异同点及优劣性,可为我国企业提高其计算准确度提供借鉴,也为进一步改进计算方法提出了建议。

Electrochemical behavior of graphite anode during anode effect in cryolite molten salts

Anodic electrochemical behavior was studied on graphite anode at 1000 ℃ in cryolite-alumina molten salt by means of cyclic voltammetry. The high current peak in a typical cyclic voltammogram was discussed. It is considered that a type of oxyfluoroaliminate complex anions reacts with carbon to form a high-resistance CF film on the anode surface at a high potential. The passivation potential is 3.28 V in 0.5% alumina-containing electrolyte, and the passivation potential increases with alumina content increasing which indicates that the alumina content determines the anodic process in the cryolite-alumina molten salt system.

Reperfusion injury after critical intestinal ischemia and its correction with perfluorochemical emulsion "perftoran"

AIM： To investigate the anti-ischemic properties of perfluorochemical emulsion ＂perftoran＂ in mesenteric region. METHODS： Experiments were conducted on 146 nonlinear white male rats weighing 200-350 g. Partial critical intestinal ischemia was induced by thorough atraumatic strangulation of 5-6 cm jejunal loop with its mesentery for 90 rain. Global critical intestinal ischemia was made by atraumatic occlusion of the cranial mesenteric artery （CMA） for 90 rain also. Perftoran （PF, 0.8-1.0 mL per 100 g） in experimental groups or 0.9% sodium chloride in control groups was injected at 75 rain of ischemic period. Mean systemic arterial blood pressure （BPM） registration, intravital microscopy and morphological examination of ischemic intestine and its mesentery were performed in both groups. RESULTS： During 90 min of reperfusion, BPM progressively decreased to 27.3±7.4% after PF administration vs 38.6±8.0% in the control group of rats with partial intestinal ischemia （NS） and to 50.3±6.9% vs 53.1±5.8% in rats after global ischemia （NS）. During the reperfusion period, full restoration of microcirculation was never registered; parts with restored blood flow had leukocyte and erythrocyte stasis and intra-vascular clotting, a typical ＂non-reflow＂phenomenon. The reduction of mesenteric 50-400 μm feeding artery diameter was significantly less in the PF group than in the control group （24±5.5% vs 45.2±3.6%, P〈0.05） 5 min after partial intestinal ischemia. This decrease progressed but differences between groups minimized at the 90th min of reperfusion （41.5±4.2% and 50.3±2.8%, respectively）. In reperfusion of rat＇s intestine, a significant mucosal alteration was registered. Villous height decreased 2.5-3 times and the quantity of crypts decreased more than twice. In the group of rats administered PF, intestinal mucosal layer was protected from irreversible post-ischemic derangement during reperfusion. Saved cryptal epithelial cells were the source of regeneration of the epithelium, which began to cover renewing intestinal villi after 24 h of blood flow restoration. View of morphological alterations was more heterogeneous in CMA groups. CONCLUSION： Systemic administration of perftoran promotes earlier and more complete structural regeneration during reperfusion in rats after partial and global critical intestinal ischemia.

Evaluation of perfluorinated compounds in seven wastewater treatment plants in Beijing urban areas

The presence of perfluorinated compounds(PFCs)in seven major wastewater treatment plants(WWTPs)in Beijing was investigated in the current study.We detected nine PFCs in all the wastewater and sludge samples.Perfluorooctane acid(PFOA)is the dominant PFCs in influents and effluents,while perfluorooctane sulfonate(PFOS)is the major contaminant in sludge.The highest PFC concentration was found in plants at Qinghe and Jiuxianqiao WWTP,while the lowest was found at Fangzhuang WWTP.The total values of PFC range from 2.88 to 176 ng/L in influents,from 5.48 to 498 ng/L in effluents,and from 1.21 to 32.0 ng/g(dry wt)in sludge.The fact that effluents usually contain higher levels of PFCs than influents suggests that additional PFCs are produced during the wastewater treatment processes.However,PFOS decreases in effluents than in influents in 62%of the water samples.This may be due to the adsorption and removal of the sludge during the active process.Perfluoroalkyl carboxylates(PFCAs)were found significantly correlated with each other in the effluents,which may indicate their similar sources or the existence of their potential precursors in the wastewater or treatment processes.The mass flows of PFC discharges into WWTPs are 0.4–51.4 mg/day,and the mass flows of PFCs in effluents exceed those in influents by 127%.Domestic and commercial wastewaters are suggested to be the major sources of PFC pollution in WWTPs in Beijing.