甲异羟肟酸-硝酸辐解产生的H2和CO

甲异羟肟酸(FHA)是有望用于乏燃料后处理的新型无盐络合剂.用5(A)分子筛填充柱与热导池检测器(TCD)联用的气相色谱法研究了HNO_3-0.2 mol/L FHA辐解产生的H_2和CO.H_2的分析是以Ar作载气,柱温为85 ℃,TCD温度为120 ℃; CO的分析是以H_2作载气,柱温为50 ℃, TCD温度为80 ℃.研究结果表明,H_2的体积分数随剂量的增加而增大,随HNO_3浓度的增大而减小;CO只有在剂量很高时才产生,且其体积分数远比H_2低,CO的体积分数随剂量的增加而增加.当c(HNO_3)≤0.5 mol/L时,CO体积分数低于0.2 mol/L FHA水溶液辐解产生的CO,但当c(HNO_3)≥1.0 mol/L时,CO的体积分数大于0.2 mol/L FHA水溶液辐解产生的CO, 且CO体积分数随c(HNO_3)的增大而增大.     

N,N-二甲基羟胺辐解产生的气态烃类的定性和定量分析

报道了用三氧化二铝毛细柱与氢火焰离子化检测器联用的气相色谱法,定性定量分析了N,N-二甲基羟胺水溶液辐解产生的气态烃类。结果表明,辐照剂量为10—1000kGy时,N,N-二甲基羟胺水溶液辐解产生的气态烃类有甲烷、乙烷、乙烯、丙烷、丙烯和正丁烷,当N,N-二甲基羟胺浓度为0.2mol/L时,甲烷的体积分数为9.996×10-6—247.5×10-6,乙烷、丙烷和正丁烷的体积分数较低,而乙烯和丙烯的体积分数则更低。甲烷的体积分数随剂量的增加而增加,而乙烷、乙烯、丙烷、丙烯和正丁烷的体积分数随剂量变化不明显。     

羟胺衍生物的辐解研究Ⅱ.N,N-二乙基羟胺辐解产物中气态烃类的定性定量分析

用三氧化二铝毛细柱与氢火焰离子化检测器联用的气相色谱法,定性定量分析了N,N-二乙基羟胺水溶液辐解产生的气态烃类。结果表明：当吸收剂量为10～1000kGy时,N,N-二乙基羟胺水溶液辐解产生的气态烃类主要有甲烷、乙烷、乙烯、丙烷和正丁烷。甲烷、乙烷、丙烷和正丁烷的体积分数都随吸收剂量的增加而增加;而乙烯的体积分数先是随剂量的增加而增加,当剂量大于500kGy时,其体积分数则随剂量的增加而明显减少。     

双酚-A型聚碳酸酯薄膜的輻射效应

本工作主要研究室温下聚碳酸酯薄膜在空气、氮气及真空等条件下受Co~(60)γ射线照射后,其单向拉伸温度-形变曲线、抗张强度、极限伸长率、纵向耐折、特性粘度、体积电阻、击穿电压和紅外光谱等物理和化学性能的变化。实驗証明,聚碳酸酯和其他含芳香基类高聚物相似,在化学和物理性能方面都具有較高的抗輻射能力。在剂量为10~6到7×10~6伦时,聚碳酸酯薄膜的热稳定性有一定的提高;但随剂量的进一步增加,它又开始变坏。到剂量为10~8伦时,明显地表示出聚碳酯分子产生了以裂解反应占优势的輻射效应。特性粘度和热稳定性能的測定結果互相吻合。照射过的薄膜全部溶于苯和氯仿。同时,随剂量的增加,溶解也快一些。在整个照射剂量范围內,都沒有凝胶产生。因此,可认为是沒有交联反应。剂量低于5×10~7伦时,体积电阻和击穿电压皆不发生較大的变化。紅外光譜測定結果表明,剂量大于10~8伦时,羥基含量随照射剂量的增加而增加。受照射的薄膜,除剂量高于7×10~7伦时有顏色的改变以外,氧化对它的作用很小。在氮气、空气中照射时,在剂量分別达5×10~8,3×10~8伦后,試样均脆裂,强度全部丧失。     

PET/CT中CT的剂量与CT图像质量关系的研究

为在保证图像质量的前提下,降低PET/CT中CT扫描部分的辐射剂量提供数据依据。用GEDiscovery ST16型号PET/CT系统,按不同的采集条件扫描CT质量控制模体,测量CT图像的相关性能指标;测量在各种管电流下的加权CT剂量指数,计算不同螺距下的容积CT剂量指数;分析CT图像质量与CT剂量的关系。结果表明:CT图像高对比度分辨力不受CT剂量影响;CT图像的低对比度分辨力随CT剂量增加而提高;CT剂量能影响CT图像的均匀性;CT图像噪声随CT剂量增加而降低,且可用一表达式来表示。得出在保证一定的CT图像质量的条件下,可以适当降低PET/CT检查中CT部分的辐射剂量的结论。     

甲异羟肟酸γ辐照稳定性

甲异羟肟酸(FHA)是有望用于乏燃料后处理的新型无盐络合剂。本工作用紫外分光光度法研究了FHA的γ辐照稳定性,并且研究了硝酸和甲基肼对FHA辐照稳定性的影响。结果表明,当剂量为10~1000 kGy时,FHA在水溶液中的辐照稳定性随FHA浓度的增加而增大,但随剂量的增加而降低;在HNO3-0.2 mol/L FHA体系中,当HNO3浓度为0.2 mol/L时,FHA的辐照稳定性略有增加,但当c(HNO3)≥0.5 mol/L时,FHA的辐照稳定性降低;在甲基肼-1.0 mol/L HNO3-0.2 mol/L FHA体系中,FHA的辐照稳定性随甲基肼浓度的增加而增大。     

羟胺衍生物的辐解研究Ⅲ.N,N-二乙基羟胺辐解产生的氢气和一氧化碳的定性定量分析

用5A分子筛填充柱与热导型检测器联用的气相色谱法．定性定量分析了N,N-二乙基羟胺水溶液辐解产生的氢气和一氧化碳。分析氢气时,以氩气为载气,柱温为85℃,检测器温度为110℃;分析一氧化碳时,以氢气为载气,柱温为50℃,检测器温度为80℃。研究结果表明：氢气的体积分数随着吸收剂量的增加而增加,而与N,N-二乙基羟胺浓度的关系不大;一氧化碳只有在很高吸收剂量时才产生,且体积分数很低。     

电子辐照PVA/CMC共混水凝胶的成胶研究

本试验利用电子辐照PVA/CMC共混水凝胶,通过外观透明度、凝胶分数、溶胀度和红外光谱分析,研究了样品中结构的变化与外观透明度、凝胶分数和溶胀度的关系,以及辐照剂量对样品中结构和性能的影响.结果表明,不同比例的PVA与相同比例的CMC组成的共混水凝胶,经电子辐照后呈现不同的宏观特性.辐照样品萃取后得到的凝胶比萃取前的混合凝胶拥有更强的吸水性,表明辐照PVA/CMC共混凝胶形成了网状结构凝胶.几种竞争反应导致不同辐照剂量下混合凝胶中凝胶含量随PVA含量的变化变得复杂.辐照后样品的红外光谱分析显示,辐照使凝胶中部分仲醇中C上链接的H原子被取代而转变为叔醇,从而产生交联.     

几种有机物对AlSUB>2/SUB>OSU

采用静态法研究了几种有机物存在时,pH对Eu(Ⅲ)和Am(Ⅲ)在Al2O3上吸附的影响。实验结果表明,在Am(Ⅲ)和Eu(Ⅲ)的浓度较低(1~10 nmol/L)、液固比为100 mL/g及离子强度为0.05 mol/kg KNO3等实验条件下,与不加入任何有机物相比,当pH=3.5~5.0时,加入水杨酸、邻苯二甲酸、邻苯二酚后,Al2O3对这2种离子的吸附率随pH增加而增加;当pH<3.5或pH>5.0时,pH对这2种离子的吸附率几乎没有影响。加入富里酸后,当pH<4.5时,2种离子的吸附率随pH增加而增加,且与加入其它有机物相比,富里酸能明显提高这2种离子的吸附率;而当pH>5.0时,2种离子的吸附率随pH增加而下降。     

PVA/PEO/Chitosan水凝胶膜的辐照法制备及其性能研究

研究了辐照剂量和壳聚糖含量对水凝胶膜性能的影响。以聚乙烯醇(PVA)、聚氧化乙烯(PEO)和壳聚糖(Chitosan)为原料,采用γ射线辐照法制备了一种新型水凝胶膜。结果表明,随着辐照剂量的增大,凝胶分数会增大,溶胀率会降低;辐照剂量达到21kGy时,凝胶分数可以达到70%,辐照剂量大于21kGy以后,拉伸强度和断裂伸长率会随着辐照剂量的增大而降低;随着壳聚糖含量的增加,水凝胶膜的凝胶分数、拉伸强度和断裂伸长率都会减小,而溶胀率会有一定的提高。辐照后壳聚糖的一些特殊官能团没有改变,将会保持它的抑菌性能,从而获得了一种新型水凝胶膜。     

Gaseous products generated by radiation degradation of N,N-diethylhydroxylamine aqueous solution

In this paper, gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA)in aqueous solution are studied. The results show that by 10～1000 kGy irradiation of the solution in DEHA volume fraction of hydrogen did not change much with different concentrations of DEHA. The volume fraction of methane and ethane decreased, but that of ethene increased, with increasing DEHA concentration. The volume fraction of hydrogen, methane and ethane increased with the dose. The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.     

Gaseous products generated by radiation degradation of N,N-diethylhydroxylamine aqueous solution

In this paper, gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA)in aqueous solution are studied. The results show that by 10～1000 kGy irradiation of the solution in DEHA volume fraction of hydrogen did not change much with different concentrations of DEHA. The volume fraction of methane and ethane decreased, but that of ethene increased, with increasing DEHA concentration. The volume fraction of hydrogen, methane and ethane increased with the dose. The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.     

Radiolytic organics in γ-ray irradiated aqueous solution of N,N-diethylhydroxylamine

N,N-diethylhydroxylamine (DEHA) is a novel salt-free reducing agent used in separating Pu and Np from U in the reprocessing of spent nuclear fuel.In this paper,we report the study on γ-radiolysis of DEHA in water and its radiolytic liquid organics by gas chromatography.The radiolysis rate of DEHA increases with the absorbed dose,but decreases with the primary DEHA concentration at 0.1-0.5 mol?L-1 irradiated to 10-1000 kGy.The main organics produced in radiolysis of DEHA are acetaldehyde,acetic acid and ethanol.The concentration of acetaldehyde increases with the primary DEHA concentration and the absorbed dose at ≤500 kGy,but over 500 kGy it decreases with increasing dose.The dependence of the concentration of acetic acid on the absorbed dose is similar to that of acetaldehyde,with a lower turning point of the dose,though.The ethanol concentration changes differently among the irradiated samples of different primary DEHA concentrations,and this is discussed.The maximum concentrations of acetaldehyde,acetic acid and ethanol are 0.029,0.014 and 0.028 mol·L-1,respectively.     

Analyses of organics in irradiated aqueous N,N-diethylhydroxylamine solution

The organics in γ-ray irradiated aqueous N, N-diethylhydroxylamine (DEHA) solution, which is used as a reducing agent in reprocessing spent nuclear fuel, were analyzed with gas chromatography equipped with FFAP capil-lary column and flame-ionization detector. It was found that irradiated DEHA solutions contained acetaldehyde, ethanol, and acetic acid. For DEHA of 0.2 mol/L irradiated to 10～1000 kGy, the concents of acetaldehyde, ethanol and acetic acid are (9.7～18.7)×10-3, (0.4～23.4)×10-3 and (6.5～11.7)×10-3 mol/L, respectively. The concentration of DEHA decreases obviously with the dose.     

N,N-二甲基羟胺辐解产生的氢气和一氧化碳的研究

With the development of nuclear power industry, more attentions have been paid on reprocessing power reactor spent fuel. Up to now, PUREX process is the only process available commercially. The process achieves uranium and plutonium separation by means of quick and quantitative reduction of Pu (Ⅳ) to Pu (Ⅲ). Therefore the reductant is very important in PUREX process. Preliminary experiment results[1] show that N, N-dimethyl hydroxylamine not only reduces rapidly Np (Ⅵ) and Pu (Ⅳ) to Np (V) and Pu (Ⅲ), but also stabilizes the Np (V)and Pu (Ⅲ) in acid solution. It may become a salt-free reductant with promising future for applications in the area[2]. However, organics decompose under intense radiation environment, and this affects its reduction efficiency,and products from the degradation may affect separation of the radioactive elements.This paper reports the qualitative and quantitative analysis of hydrogen and carbon monoxide produced by 60Co y-ray degradation of N, N-dimethyl hydroxylamine. The analyses of hydrogen and carbon monoxide were performed by gas chromatography, in which a 2m column packed with 5A molecular sieve and thermal conduc tivity detector[3] were used. The analysis of hydrogen employed argon as carrier gas, the column temperature was 80℃ and the detector temperature was 110℃. The analysis of carbon monoxide used hydrogen as carrier gas, the column temperature was 50℃ and the detector temperature was 80 ℃. The results show that when the concentration of N, N-dimethyl hydroxylamine was between 0.1 mol/L and 0.5 mol/L and the dose delivered by the irradiation was 10-1000 kGy, the volume fraction of hydrogen was (8.0-303.9)× 10-3; and the volume fraction of carbon monoxide is (0-1.7)× 10-3. The volume fraction of hydrogen increased with increasing dose, and it has little relationship with concentration change of N, N-dimethyl hydroxylamine when the irradiation dose was bellow 500 kGy, whereas it increased with the increasing concentration of N, N-dimethyl hydroxylamine when the dose was higher than 500 kGy. The volume fraction of carbon monoxide has little relationship with both the irradiation dose and N, N-dimethyl hydroxylamine concentration.     

Analyses of organics in irradiated aqueous N, N-diettiyihydroxylamine solution

The organics in γ-ray irradiated aqueous N, N-diethylhydroxylamine （DEHA） solution, which is used as a reducing agent in reprocessing spent nuclear fuel, were analyzed with gas chromatography equipped with FFAP capii- lary colunm and flame-ionization detector. It was found that irradiated DEHA solutions contained acetaldehyde, ethanol, and acetic acid. For DEHA of 0.2 mol/L irradiated to 10-1000 kGy, the concents of acetaldehyde, ethanol and acetic acid are （9.7-18.7）×10^3, （0.4-23.4）×10^3 and （6.5-11.7）×10^3 mol/L, respectively. The concentration of DEHA decreases obviously with the dose.     

Gaseous products of aqueous N,N-dimethyl hydroxylamine degraded by radiation

In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.     

PVA/PVP/ws-chitosan水凝胶伤口敷料的辐射制备及性能表征

采用γ射线辐射法制备了聚乙烯醇(PVA)/聚乙烯基吡咯烷酮(PVP)脉溶性壳聚糖(ws-chitosan)共混水凝胶.研究了辐射剂量、ws-chitosan含量及增塑剂(聚乙二醇(PEG)或甘油)对水凝胶性能的影响.实验发现,随着辐射剂量的增大,凝胶分数增大,并在剂量大于27 kGy时达到饱和;ws-chitosan含量增大及加入增塑剂PEG或甘油后,水凝胶的凝胶分数和强度都会减小,而相应的溶胀度会显著增大.通过高级流变仪(ARES)对水凝胶弹性模量的测试显示,随吸收剂量的增加,凝胶强度会相应增大,但在27 kGy以上出现饱和.