60 Coγ射线辐照五种常见渔药在水溶液中降解作用的研究

本文采用0—10kGy的60Coγ射线对水溶液中的磺胺二甲基嘧啶、噁喹酸、氯霉素、呋喃唑酮、土霉素进行处理,并测定了环境的酸碱性、空气、温度对辐照降解率的影响。结果表明,60Coγ射线辐照处理能显著降解五种常见渔药在水中的残留,吸收剂量越大,渔药的降解率越高;初始浓度越低,越有利于渔药的去除。当吸收剂量为8kGy时,五种渔药(初始浓度100mg/L)的降解率均达到90%以上,酸碱性和空气环境对不同种类的渔药降解率影响有一定的差异,降低温度对渔药降解有明显抑制作用。     

^60Coγ射线辐照降解吡虫啉稀水溶液

采用^60Coγ射线辐照降解吡虫啉稀水溶液,并对辐照前后的水样进行高效液相色谱（HPLC）、离子色谱（IC）和高效液相色谱-质谱联用（HPLC—MS）等检测。实验结果表明,吡虫啉的降解率随吸收剂量的增大而不断增大,当吸收剂量为1．56kGy时,降解率达到100％;吡虫啉的辐照降解产物包括Cl^-1、NO2、NO3-和NH4^＋四种无机产物,2-chloro-5-imidazol-1-ylmethyl-pyridine、1-（6-chloro-pyridin-3-ylmethyl）-1,3-dihydro—imidazol-2-ylideneamine、单羟基化吡虫啉和双羟基化吡虫啉4种有机产物。强氧化性的·OH容易进攻吡虫啉分子中的C=N键、N-N键、C—Cl键以及亚甲基中的C—H键。     

γ射线辐照降解乳酸左氧氟沙星及产物抑菌活性分析

研究了γ射线辐照下10μg/mL乳酸左氧氟沙星的降解,空气条件下当剂量达到1kGy时,降解率达到99%,而G值则随着剂量增加而降低;通过高效液相色谱-质谱联用仪(LC-MS)分析,推测出5种主要的降解产物(m/z346、330、318、302、274)和最可能的降解途径,并与氮气条件下的降解进行比较,探讨初步降解机理;对大肠杆菌在含有乳酸左氧氟沙星溶液的营养肉汤中生长状况分析可知,产物为m/z346的分子仍然具有活性成分,可以抑制大肠杆菌的生长,仅当剂量大于3kGy活性才完全消失。因此3kGy应为乳酸左氧氟沙星的最佳辐照剂量。辐照技术可以很有效地降解抗生素,确定辐照剂量时需要把降解产物活性考虑在内。     

γ射线辐照水溶液中氯霉素的降解研究

研究了γ射线辐照水溶液中氯霉素的降解规律,并对辐解产物进行了初步探讨.根据辐照前后高效液相色谱(High performance liquid chromatography,HPLC)图谱中氯霉素峰面积变化,分析得出氯霉素随吸收剂量和初始浓度的降解规律.利用液相色谱串联质谱(Liquid chromatography tandem mass spectrometry,LC/MS/MS),定性分析氯霉素的辐解产物.结果表明,氯霉素残留量随吸收剂量和初始浓度的变化关系满足指数方程;氯霉素辐射降解后形成了30个以上的辐解产物,它们在氯霉素检测波长278nm下的响应值均较低;确定了氯霉素在不同辐解条件下均出现的8种主要辐解产物,它们的准分子离子质量[M-H]分别为:353、337、335(A)、335(B)、319、289、127、166,并对主要辐解产物进行了初步的结构解析.     

4-氯酚的γ射线辐照降解研究

利用^60Coγ射线(2．2—14．9kGy)辐照4-氯酚水溶液，研究了其辐照降解特性。通过对辐照前后4-氯酚的紫外可见光谱、有机氯脱除率、化学需氧量(Chemical oxygen demand,COD)去除率的研究，探讨了吸收剂量、H2O2加入量、初始浓度、溶液pH值对降解效果的影响。结果表明，这一辐射技术能有效降解4-氯酚，有机氯脱除率可达100％，COD去除率可达65．8％。     

4–氯酚的γ射线辐照降解研究

利用 Co γ射线(2.2—14.9kGy)辐照 4-氯酚水溶液,研究了其辐照降解特性。通过对辐照前后 4-氯 60酚的紫外可见光谱、有机氯脱除率、化学需氧量(Chemical oxygen demand, COD)去除率的研究,探讨了吸收剂量、H2O2加入量、初始浓度、溶液 pH 值对降解效果的影响。结果表明,这一辐射技术能有效降解 4-氯酚,有机氯脱除率可达 100%,COD 去除率可达 65.8%。     

甲基橙溶液的辐射降解研究

以60Coγ射线为辐射源,对偶氮染料甲基橙进行了γ射线辐射降解研究,探讨了H2O2加入量、吸收剂量、初始浓度和溶液pH值对辐射降解结果的影响。结果表明,γ射线辐射能有效降解甲基橙,化学需氧量(CoD)去除率可达80％以上,脱色效果显著。H2O2加入量、吸收剂量、初始浓度均与甲基橙的降解效率有关,而溶液的pH值对降解影响不大。实验证实,利用γ射线辐射降解技术处理染料废水是一种可行的方案。     

灭菌剂量下γ射线辐照对环烯烃共聚物的影响及机理研究

由乙烯和降冰片烯共聚合成的环烯烃共聚物（Cyclic Olefin Copolymer,COC）具有良好的透光性、水蒸气阻隔性,以及生物相容性,适用于医疗器械和药物包装领域。这类COC医疗用品通常采用辐照灭菌来确保生物安全性,然而辐射过程会使分子链断裂产生自由基,不可避免地会发生辐射裂解、氧化、变色等现象。因此,探究电离辐射引发的自由基反应导致的COC性能变化对COC医疗用品的辐照灭菌应用具有重要意义。为了研究辐照灭菌剂量下COC的辐射效应,考察了剂量范围内γ射线对COC的化学结构、自由基信号、玻璃化转变温度、热稳定性、分子量分布、表面性质以及熔融指数的影响。结果显示：在空气中COC经辐照产生的自由基浓度随着吸收剂量增大线性增加;随着吸收剂量的增大,包括羰基、羟基类化合物等辐射氧化产物的平均分子量减小,辐射降解占优势;同时COC表面亲水性增强,熔融指数增加。辐射导致的分子链断裂以及自由基的氧化反应是COC降解的主要原因。     

γ射线对水溶液中赭曲霉毒素A降解效果的研究

为了探讨γ射线辐照对于水溶液中赭曲霉毒素A的降解效果,采用60Coγ射线辐照水溶液中的赭曲霉毒素A.用赭曲霉毒素A标准溶液确定高效液相色谱检测技术的线性关系和检出限,然后基于高效液相色谱检测技术研究辐照对水溶液中赭曲霉毒素A的降解效果.结果显示,水溶液中赭曲霉毒素A的降解率随着辐照剂量的增加而增加;在4kGy的辐照剂量...     

辐照法制备纳米银粉的研究

研究了~(60)Coγ射线辐照硝酸银水溶液体系制备纳米银粉。利用XRD、TEM、DSC、LSPSDA分别表征了材料的物相、粒径、形貌、以及熔点。结果表明,表面活性剂(PCM)在0.6-2.2g/100mL范围内,反应得到的纳米银粒子的粒径随浓度的增加而减小,纳米银粒子的熔点随着粒径的减小而减小。表面活性剂浓度为2.2g/100mL时,粒径最小可达到19.9nm,相应熔点为126.18℃。不同PH值的辐照溶液所得产物均为单质银颗粒,银盐溶液的酸碱性对其辐照产物基本不产生影响。     

Plasma Induced Degradation of Benzidine in Aqueous Solution

The degradation of benzidine in aqueous solution by the low temperature plasma was examined. The results showed that the concentration of medium and the value of pH have an appreciable effect on the degradation of benzidine. What is more important is that iron ions acting as a catalyst play an important role in this reaction. For exploring the degradation mechanism of benzidine, some of the intermediate products were recorded by HPLC (high performance liquid chromatography).     

Degradation of Chloroanilines in Aqueous Solution by Contact Glow Discharge Electrolysis

Contact glow discharge electrolysis of some chloroanilines in sodium sulfate was investigated in different initial concentrations.Each of them underwent the dechlorination,deamination theough oxidative degradation,and were eventually decomposed into hydrogen carbonate and carbon dioxide.It was testifies that the chlorine atomn and amidogen could be transformed into chloride ion and nitrite ion ,respectively.Fe^2 has a remarkable catalytic effect on the degradation of them.On the basis of the detailed analysis of the intermediate products and kinetic hehaviors,the reaction pathway was proposed,in which the attack of hydroxyl radical on the benzene ring of starting material might be a key step.     

EM>N/EM>，EM>N-/EM>二乙基

研究了N,N-二乙基羟胺(DEHA)水溶液辐解产生的气态烃。当DEHA浓度为0.1~0.5 mol/L,剂量为10~1 000 kGy时,甲烷、乙烷、丙烷和正丁烷的体积分数随剂量的增加而增加,但随DEHA浓度的增加而减少。乙烯和丙烯的体积分数随DEHA浓度的增加而增大,它们与剂量的关系与DEHA浓度有关。     

Oxidative Degradation of o-Chlorophenol with Contact Glow Discharges in Aqueous Solution

Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe^2 had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe^2 , 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.     

Atmospheric Pressure Plasma Jet in Organic Solution: Spectra,Degradation Effects of Solution Flow Rate and Initial pH Value

The organic compounds of p-nitrophenol （PNP） solution was treated by the active species generated in a stirred reactor by an atmospheric pressure plasma jet （APPJ）. The emission intensities of hydroxyl （OH）, oxygen （O）, nitric oxide （NO）, hydrogen （H） and molecular （N2） were measured by optical emission spectroscopy （OES）. The relations between the flow rates of the PNP solution and degradation, the degradation effects and initial pH value of the solution were also investigated. Experimental results show that there exist intense emissions of O （777.1 nm）, N（337.1 nm）, OH （306-310 nm） and NO band （200-290 nm） in the region of plasma. Given the treatment time and gas flow rate, the degradation increased as a function of discharge energy and solution flow rate, respectively. The solution flow rate for the most efficient degradation ranged from 1.414 m/s to 1.702 m/s, and contributed very little when it exceeded 2.199 m/s. This indicates the existence of diffusion-controlled reactions at a low solution flow rate and activation- controlled reactions at a high solution flow rate. Moreover, increasing or decreasing the initial pH value of neutral PNP solution （pH=5.95） could improve the degradation efficiency. Treated by APPJ, the PNP solutions with different initial pH values of 5.95, 7.47 and 2.78 turned more acidic in the end, while the neutral solution had the lowest degradation efficiency. This work clearly demonstrates the close coupling of active species, photolysis of ultraviolet, the organic solution flow rate and the initial pH value, and thus is helpful in the study of the mechanism and application of plasma in wastewater treatment.     

不同类型电离辐射对聚醚聚氨酯材料的辐射效应

文章讨论聚醚聚氨酯材料经γ射线和电子束两种电离辐射辐照后的辐射效应。采用气相色谱、差示扫描量热分析和电子自旋共振技术，研究材料经不同类型电离辐射辐照后材料的热性能和自由基强度的变化及其辐解气体产物的种类和G值。结果表明，γ射线和电子束辐照聚醚聚氨酯材料时，二者对材料的作用机理虽相同，但能量淀积方式却不同，导致自由基数量和强度有所不同，同时材料的热性能和辐解气体小分子也存在差异。     

甲基乙烯基硅泡沫材料在复合条件下的辐射效应研究

为考察甲基乙烯基硅泡沫材料在不同条件下的辐射效应,开展了受压状态下材料经⁶⁰Co γ射线辐照后的热老化和湿热老化实验。采用扫描电镜、傅里叶转换红外光谱仪、固体核磁共振仪、万能材料试验机和蠕变松弛试验机等手段剖析了材料微观结构和宏观性能。结果表明,不同条件下老化后甲基乙烯基硅泡沫材料的泡孔有减小的趋势。²⁹Si交叉极化的NMR分析发现材料中有机硅链段峰的强度随吸收剂量的增大而升高,¹³C交叉极化的NMR分析表明γ射线辐照后材料的结构规整性有所降低。辐射后热老化样品的拉伸强度总比辐射后湿热老化样品的低,辐射老化和湿热老化的协同作用对材料的应力松弛率影响非常明显。     

γ成像数值模拟与初步实验分析

基于Geant4模拟开发平台,对γ成像系统进行了被动式成像数值模拟,并用γ相机对标准密封γ点源进行辐射成像实验,初步分析了便携式γ射线成像系统的成像特点.结果表明:该系统成像效果与源强、距离、时间等密切相关,源强越强,距离越近,清晰成像所需时间也就越短,且可以准确定位γ放射源,精确热点分布定位.     

Degradation of Microcystin-LR by Gas-Liquid Interfacial Discharge Plasma

In this study, we report on the degradation of microcystin-LR （MC-LR） by gas- liquid interracial discharge plasma. The influences of operation parameters such as average input voltage, electrode distance and gas flow rate are investigated. Experimental results indicate that the input voltage and gas flow rate have positive influences on MC-LR degradation, while the electrode distance has a negative one. After 6 min discharge with 25 kV average input voltage and 60 L/h air aerati by discharge both in on, the degradation rate of MC-LR achieves 75.3%. distilled water and MC-LR solution are measured H202 and 03 generated Moreover, an emission spectroscopy is used as an indicator of the processes that take place on the gas-liquid boundary and inside plasma. Varied types of radicals （O, .OH, CO, 03, etc.） are proved to be present in the gas phase during gas-liquid interfacial discharge.     

甲壳胺的辐射降解

研究了甲壳胺的辐射降解效应 ,发现γ射线辐照使甲壳胺 (固态 )分子量降低 ,其裂解G(S)值为 0 .5 7(inN2 )和 0 .75 (inair) ,当吸收剂量为 184 .1kGy时 ,分子量从 1.0 7× 10 6分别降为1.72× 10 5和 1.16× 10 5;使用高能电子束辐照 ,吸收剂量为 2 0 0kGy时 ,甲壳胺的分子量由 1.14×10 6降为 7.67× 10 4 ,其裂解G(S)值为 1.0 2 (inair)。