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微流控辅助内凝胶工艺制备单分散氧化铀微球
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作者 徐瑞 马景陶 +6 位作者 邓长生 郝少昌 赵兴宇 李建军 李自强 刘兵 唐亚平 《陶瓷学报》 CAS 北大核心 2023年第6期1217-1223,共7页
内凝胶工艺由于制备氧化铀微球球形度好而受到广泛关注。但是内凝胶工艺仍存在一些难点,如制备的微球尺寸略有不均,这不利于内凝胶工艺的大规模应用。在本项工作中特引入微流控辅助内凝胶工艺来制备单分散溶胶液滴。单分散溶胶液滴经洗... 内凝胶工艺由于制备氧化铀微球球形度好而受到广泛关注。但是内凝胶工艺仍存在一些难点,如制备的微球尺寸略有不均,这不利于内凝胶工艺的大规模应用。在本项工作中特引入微流控辅助内凝胶工艺来制备单分散溶胶液滴。单分散溶胶液滴经洗涤、干燥和烧结后即可获得单分散的氧化铀微球。研究表明通过微流控辅助内凝胶工艺可以制备出尺寸变异系数≤1%、球形度1.01的单分散氧化铀微球。微流控辅助内凝胶工艺操作简便,在制备高质量核燃料微球方面具有广泛的应用前景。 展开更多
关键词 氧化铀微球 内凝胶工艺 微流控 单分散 球形度
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用内凝胶法制备球形Y_2O_3-ZrO_2等离子喷涂粉料 被引量:1
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作者 李建军 姜长印 +2 位作者 万春荣 吴宇平 郝建民 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2000年第3期487-492,共6页
以无机物为前驱物,用内凝胶法制备了适合于等离子喷涂的、粒径在10~50μm范围内的、用氧化钇稳定的氧化锆(YSZ)球形粉末,实验结果表明,通过改变乳化条件可以控制这种粉末的形貌、粒径和粒度分布.利用SEM和光学显微镜观察发现,... 以无机物为前驱物,用内凝胶法制备了适合于等离子喷涂的、粒径在10~50μm范围内的、用氧化钇稳定的氧化锆(YSZ)球形粉末,实验结果表明,通过改变乳化条件可以控制这种粉末的形貌、粒径和粒度分布.利用SEM和光学显微镜观察发现,用该方法得到的粉末主要是球形的,并且符合粒径分布的要求(5~50μm).致密的球形粉末显示出良好的流动性.差热分析表明,用47mol%氧化钇稳定的氧化锆(YSZ)粉末在468℃有一放热峰,是YSZ粉末的相转变温度.XRD分析表明,上述粉末在800℃条件下煅烧可以得到100%非平衡四方相(t’)的YSZ粉末,没有单斜相存在. 展开更多
关键词 内凝胶 等离子喷涂 粉末 氧化钇 氧化锆 制备
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UO_(2)陶瓷微球制备工艺中凝胶的回收再利用研究
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作者 王特 卢长先 +3 位作者 李佳 尚亚莉 王国华 杨海涛 《陶瓷学报》 CAS 北大核心 2023年第3期541-546,共6页
研究了温度、pH、贮存时间、Urea与U摩尔比等因素对溶胶稳定性的影响。结果表明,当贮存温度为0℃时,溶胶可以稳定贮存6 h,随着温度和贮存时间的提高,溶胶的黏度会逐渐增大;尿素对溶胶中金属离子具有保护作用,当Urea与U摩尔比大于1时,有... 研究了温度、pH、贮存时间、Urea与U摩尔比等因素对溶胶稳定性的影响。结果表明,当贮存温度为0℃时,溶胶可以稳定贮存6 h,随着温度和贮存时间的提高,溶胶的黏度会逐渐增大;尿素对溶胶中金属离子具有保护作用,当Urea与U摩尔比大于1时,有助于制备出球形度好的陶瓷微球。为了探究溶胶固化的根本原因,通过对比实验验证了引起溶胶凝固的主要原因是铀酰离子发生了水解缩合反应。最后,设计开发了凝胶煅烧回收的技术路线,X射线衍射结果证明在800℃下煅烧后凝胶完全转化为U3O8粉末,通过化学滴定法测定铀含量为83.24%,可直接用于缺酸溶解制备缺酸硝酸铀酰溶液,接着通过配胶、分散、洗涤、老化、烧结过程制备出了尺寸均匀的陶瓷微球。 展开更多
关键词 稳定性 煅烧回收 陶瓷微球 内凝胶
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内凝胶工艺结合碳热氮化法制备ZrN纳米粉体 被引量:1
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作者 赵世娇 马景陶 +4 位作者 赵兴宇 郝少昌 李自强 邓长生 刘兵 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2020年第2期732-736,共5页
采用内凝胶工艺制得无定形的氧化锆凝胶与炭黑均匀混合的前驱体粉末,获得的前驱体在氮气条件下进行碳热氮化处理后得到氮化锆(ZrN)纳米粉体。结合热重/差式扫描量热分析(TGA/DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜... 采用内凝胶工艺制得无定形的氧化锆凝胶与炭黑均匀混合的前驱体粉末,获得的前驱体在氮气条件下进行碳热氮化处理后得到氮化锆(ZrN)纳米粉体。结合热重/差式扫描量热分析(TGA/DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等手段,对内凝胶前驱体的热处理行为、所得产物的物相组成、微观形貌及显微结构等进行了表征。研究结果表明,氮化温度的升高有利于氮化程度的提高,1400℃氮化温度下可得到纯相纳米ZrN粉体;此外,碳的引入在热处理过程中起到了必要的还原作用,且碳的加入量需要适当,C/Zr摩尔比接近2是获得纯相ZrN粉体产物较为合适的条件。 展开更多
关键词 碳热氮化 内凝胶 ZRN 纳米粉体 温度
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利用毛细管微流体装置辅助内凝胶工艺制备小尺寸ZrO2微球
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作者 徐瑞 马景陶 +4 位作者 郝少昌 赵兴宇 李自强 邓长生 刘兵 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2020年第2期572-576,共5页
寻找到一种室温(25℃)下稳定15 h不固化且成球较好的胶液配方,利用毛细管微流体装置辅助内凝胶工艺制备出小尺寸(<120μm)的ZrO2陶瓷微球,并对影响ZrO2微球尺寸的因素进行分析。结果表明:其它条件相同的情况下,硅油的流量或者粘度越... 寻找到一种室温(25℃)下稳定15 h不固化且成球较好的胶液配方,利用毛细管微流体装置辅助内凝胶工艺制备出小尺寸(<120μm)的ZrO2陶瓷微球,并对影响ZrO2微球尺寸的因素进行分析。结果表明:其它条件相同的情况下,硅油的流量或者粘度越大,ZrO2微球尺寸越小。胶液的流量越大或者毛细管微流体装置喉口尺寸越大,ZrO2微球尺寸越大;通过图像识别发现,ZrO2陶瓷微球的CV值都小于5%,说明该方法制备出的ZrO2陶瓷微球尺寸均一;通过SEM和XRD发现ZrO2陶瓷微球致密,呈立方相。 展开更多
关键词 内凝胶工艺 毛细管微流体装置 室温 小尺寸ZrO2微球
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内胶凝工艺制备UO_2微球 被引量:2
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作者 赵兴宇 马景陶 +4 位作者 高勇 郝少昌 邓长生 刘兵 唐亚平 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2015年第S1期550-553,共4页
采用内凝胶工艺,通过溶解、配胶、分散、陈化、洗涤、干燥、焙烧、还原及烧结等工序,成功制备了粒径约为650μm的UO_2微球。通过旋转粘度计测量了胶液粘度随温度、时间的变化,进而对胶液的稳定性进行了研究。研究了胶液组份的配比、胶液... 采用内凝胶工艺,通过溶解、配胶、分散、陈化、洗涤、干燥、焙烧、还原及烧结等工序,成功制备了粒径约为650μm的UO_2微球。通过旋转粘度计测量了胶液粘度随温度、时间的变化,进而对胶液的稳定性进行了研究。研究了胶液组份的配比、胶液p H值、铀浓度及HMTA-Urea浓度对微球显微结构和性能的影响,通过体视显微镜观察了干燥后微球的表面形貌,通过SEM观察了烧结后UO_2微球的晶粒尺寸与致密化程度。通过实验得到了胶液在不同温度下的稳定时间和表观形貌完好无开裂的UO_2微球。成功地研究了适用于制备UO_2微球的稳定的内凝胶工艺技术。 展开更多
关键词 内凝胶 液稳定性 UO2微球
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Mucin gene expression in bile of patients with and without gallstone disease,collected by endoscopic retrograde cholangiography 被引量:4
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作者 Alexander Vilkin Alex Geller +1 位作者 Zohar Levi Yaron Niv 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第19期2367-2371,共5页
AIM: To investigate the pattern of mucin expression and concentration in bile obtained during endoscopic retrograde cholangiography (ERC) in relation to gallstone disease.METHODS: Bile samples obtained at ERC from... AIM: To investigate the pattern of mucin expression and concentration in bile obtained during endoscopic retrograde cholangiography (ERC) in relation to gallstone disease.METHODS: Bile samples obtained at ERC from 29 consecutive patients, 17 with and 12 without gallstone disease were evaluated for mucin content by gel filtration on a Sepharose CL-4B column. Dot blot analysis for bile mucin apoproteins was performed with antibodies to Mucin 1 (MUC1), MUC2, MUC3, MUC5AC, MUC5B and MUC6. Staining intensity score (0-3) was used as a measure of antigen expression.RESULTS: MUCl, MUC2, MUC3, MUCSAC, MUC5B and MUC6 were demonstrated in 34.4%, 34.4%, 51.7%, 51.7%, 55.1% and 27.5% of bile samples, respectively.The staining intensity scores were 0.62 ± 0.94, 0.58 ± 0.90, 0.79 ± 0.97, 1.06 ± 1.22, 1.20 ± 2.26 and 0.41 ± 0.73, respectively. Mean mucin concentration measured in bile by the Sepharose CL-4B method was 22.8 ± 24.0 mg/mL (range 3.4-89.0 mg/mL). Mean protein concentration was 8.1 ± 4.8 mg/mL (range 1.7-23.2 mg/mL).CONCLUSION: High levels of MUC3, MUC5AC and MUC5B are expressed in bile aspirated during ERC examination. A specific pattern of mucin gene expression or change in mucin concentration was not found in gallstone disease. 展开更多
关键词 BILE Bile ducts Endoscopic retrograde cholangiography MUCIN
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Cyclooxygenase-2 polymorphisms and the risk of esophageal adeno-or squamous cell carcinoma 被引量:11
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作者 Jón O Kristinsson Paul van Westerveld +7 位作者 Rene HM te Morsche Hennie MJ Roelofs T Wobbes Ben JM Witteman Adriaan CITL Tan Martijn GH van Oijen Jan BMJ Jansen Wilbert HM Peters 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第28期3493-3497,共5页
AIM: TO determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 CCOX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: ... AIM: TO determine whether -1195 A→G and/or -765 G→C polymorphisms in Cyclooxygenase-2 CCOX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. RESULTS: The distribution of the -1195A→G polymorphism was significantly different in esophageal cancer patients compared to controls. The -1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the -1195AA genotype as a reference. The -765 G→C genotype distribution was not different between the two groups. The GG/ GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance. CONCLUSION: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma. 展开更多
关键词 ADENOCARCINOMA CYCLOOXYGENASE-2 ESOPHAGUS Genetic polymorphism Squamous cellcarcinoma
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Genotoxic Effects in Mice Exposed to Radon Emissions in Indoor Conditions. Comparison between in utero and Neonatal Exposures
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作者 Cristiano Foschi Manuel Luis Orta +2 位作者 Licia Radicchi Germana Szpunar Mauro Cristaldi 《Journal of Life Sciences》 2016年第2期66-76,共11页
The purpose of this study was to develop a biological model to evaluate the genotoxic effects of natural emissions of Radon-222 and its decay products. To this aim, mice of the Swiss CD1 strain were exposed to Radon f... The purpose of this study was to develop a biological model to evaluate the genotoxic effects of natural emissions of Radon-222 and its decay products. To this aim, mice of the Swiss CD1 strain were exposed to Radon for different periods (adult life, early postnatal and in utero exposure) and two simple but accurate mutagenicity tests (Micronucleus test and the Comet assay) were applied to the peripheral blood of mice. The study was carried out in two small towns in Latium region--ltaly, where radon pollution is notoriously present due to the volcanic soils. One experiment was carried out in the cellar of a house in Ciampino (Rome) and two experiments were performed in an old cellar in Vetralla (Viterbo). The results showed that in all mice groups exposed to natural emissions of radon and its decay products, the micronucleated erythrocytes frequency (ME) was significantly higher than that observed in the mice control. The single cell gel electrophoresis (Comet assay) was performed in lymphocytes of adult mice in the last experiment. The results for this test also show that DNA damage was higher than in the cells of the mice control and the cells of mice exposed for a shorter period of time. To confirm these findings, the single cell gel electrophoresis (Comet assay) was performed in lymphocytes of adult mice in the last experiment. Similarly, this result could be linked to a greater sensitivity of neonatal mice to radon emissions compared with intrauterine mice. Further investigations on the effects of radon and its decay products during the intrauterine life and the first neonatal period should be performed to better clarify its genotoxic activity. 展开更多
关键词 RADON GENOTOXICITY DNA damage micronucleus test comet assay.
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A microfluidic photolithography for controlled encapsulation of single cells inside hydrogel microstructures 被引量:4
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作者 JiangJiang Liu Dan Gao +1 位作者 SiFeng Mao Jin-Ming Lin 《Science China Chemistry》 SCIE EI CAS 2012年第4期494-501,共8页
A microfluidic approach to generate hydrogel microstructures inside microchannels for controlled encapsulation of single cells was developed. The method was based,on a modified microscope projection photolithography w... A microfluidic approach to generate hydrogel microstructures inside microchannels for controlled encapsulation of single cells was developed. The method was based,on a modified microscope projection photolithography which allowed for the photopolymerization of poly(ethylene glycol) diacrylate (PEGDA) inside microchannels. Uniformsized hydrogel microstmctures (-50 pan in diameter) were generated one by one with determined positions to encapsulate single cells without losing the viability. Cells of interest could be identified by any kinds of visible labels to be selectively encapsulated inside the formed hydrogel microstructures. Large-scale encapsulation of single cells was achieved with a relatively high efficiency of 80% and the viability of encapsulated cells could be guaranteed by removing the dead cells identified with Trypan blue. This method is simple, fast and convenient to pattern the microchannels with single cells for a wide range of cell-based applications. For demonstration, two intracellular enzyme assays of carboxylesterase were performed to investigate the distribution of enzyme concentrations and the kinetic information within the encapsulated single HepG2 cells. 展开更多
关键词 microfluidic single cells hydrogel microstructures HepG2 cells enzyme assay
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