期刊文献+
共找到23篇文章
< 1 2 >
每页显示 20 50 100
自动量化的肿瘤-间质比预测胃癌新辅助化疗疗效
1
作者 仇文涛 李振辉 +4 位作者 焦一平 王向学 张深燕 吴琳 徐军 《中国肿瘤临床》 CAS CSCD 北大核心 2023年第23期1203-1210,共8页
目的:探讨通过深度学习的方法来全自动定量评估术前活检标本的肿瘤-间质比(tumor-stroma ratio,TSR)是否可以预测胃癌患者新辅助化疗(neoadjuvant chemotherapy,NAC)疗效。方法:选取2013年3月至2020年3月在云南省肿瘤医院接受NAC治疗的... 目的:探讨通过深度学习的方法来全自动定量评估术前活检标本的肿瘤-间质比(tumor-stroma ratio,TSR)是否可以预测胃癌患者新辅助化疗(neoadjuvant chemotherapy,NAC)疗效。方法:选取2013年3月至2020年3月在云南省肿瘤医院接受NAC治疗的胃癌患者的术前活检切片148张和手术切除切片43张。构建肿瘤区域分割模型和上皮-间质分割模型,使用手术切除切片训练和评估模型,在活检切片上预测,取二者预测结果的交集,根据TSR的定义得到TSR值。根据术后病理学肿瘤退缩分级(tumor regression grade,TRG)将所有患者分为反应良好者(TRG 0~1)和反应不良者(TRG 2~3)。采用单因素和多因素回归分析TSR与胃癌新辅助化疗疗效的相关性。结果:肿瘤组织分割模型的IOU(intersection over union)为0.94,上皮-间质分割模型的IOU为0.88。以44.93%和70.22%作为TSR的临界值,将患者分为低、中、高间质比组,三组之间反应良好者比例具有显著性差异(P<0.05)。多因素分析显示,TSR是治疗前对胃癌NAC反应的独立预测因子(OR=0.10,95%CI:0.03~0.32)。使用常规临床信息预测治疗响应的基础上,加入TSR三分类等级作为治疗响应的预测变量时,曲线下面积(area under curve,AUC)可从0.71提升至0.85。结论:该模型能够在病理切片上自动分割肿瘤区域、上皮区域和间质区域,并能够自动、准确的计算出TSR,同时发现基于此方法自动计算的TSR可以预测NAC疗效。 展开更多
关键词 肿瘤-间质比 新辅助化疗 语义分割 肿瘤微环境 病理缓解
下载PDF
纳米零价铁材料对放射性核素铀的去除行为研究
2
作者 王祥学 王敏 +3 位作者 段恩喆 孟璐瑶 于淑君 陈岚 《中国科学:化学》 CAS CSCD 北大核心 2023年第6期921-931,共11页
核能的快速发展产生了大量含U(Ⅵ)的废水亟待处理.纳米零价铁(nZVI)具有低成本、易制备和丰富的活性位点等优势,近年来被用于水中放射性核素的去除.本文简单介绍了nZVI基材料的制备方法及其在放射性核素U(Ⅵ)去除方面的应用.首先,综述了... 核能的快速发展产生了大量含U(Ⅵ)的废水亟待处理.纳米零价铁(nZVI)具有低成本、易制备和丰富的活性位点等优势,近年来被用于水中放射性核素的去除.本文简单介绍了nZVI基材料的制备方法及其在放射性核素U(Ⅵ)去除方面的应用.首先,综述了nZVI基材料常用的制备方法,包括硼氢化物还原法、高能机械球磨法和绿色合成法.进而,总结了溶液pH、反应时间、反应温度和共存离子对U(Ⅵ)去除效果的影响,以及通过光谱分析和理论计算对于nZVI基材料与U(Ⅵ)的微观作用机制的研究.最后对nZVI基材料去除放射性核素U(Ⅵ)的应用前景与技术难点进行分析并给出个人见解,为开发基于nZVI材料去除U(Ⅵ)污染物的技术路线提供参考. 展开更多
关键词 纳米零价铁 U(Ⅵ) 合成方法 去除机理 分析表征
原文传递
金属有机骨架和MXene复合材料用于高效快速海水提铀
3
作者 张姝 赵兵 +2 位作者 刘丽杰 王祥学 于淑君 《中国科学:化学》 CAS CSCD 北大核心 2023年第9期1724-1734,共11页
MXene作为一种新型环境友好材料,因其化学性质不稳定,且不能有效地平衡层间的静电斥力,堆积和群聚阻碍了其有效表面和电子、离子的传输速度,限制了其实际应用.金属有机框架(MOFs)具有丰富的配位、可调节的孔隙率和超高的比表面积.本研... MXene作为一种新型环境友好材料,因其化学性质不稳定,且不能有效地平衡层间的静电斥力,堆积和群聚阻碍了其有效表面和电子、离子的传输速度,限制了其实际应用.金属有机框架(MOFs)具有丰富的配位、可调节的孔隙率和超高的比表面积.本研究通过水热法将沸石咪唑框架(ZIFs)纳米颗粒与MXene纳米片结合起来,合成了ZIFs@MXene复合材料,并将其用于海水提铀.宏观实验发现,ZIF-8@MXene和ZIF-67@MXene均表现出优异的吸附效果,能够快速达到反应平衡(~30 min),吸附动力学数据符合准二级动力学模型.Freundlich模型很好地拟合了ZIF-8@MXene的热力学数据,其最大吸附能力为447.4 mg g^(-1),说明UO_(2)(CO_(3))_(2)^(2-)在复合材料表面进行多相吸附过程.Langmuir模型更好地拟合了ZIF-67@MXene的热力学数据,其最大吸附量为453.6 mg g^(-1),表明吸附过程是单层吸附并且活性位点均匀地分散在吸附剂上.根据反应前后X射线光电子能谱(XPS)和傅里叶变换红外光谱(FTIR)分析,发现羟基(–OH)、氮基(C=N–)和含氧官能团(Zn/Co–O和N–O)在吸附过程中共同作用,化学吸附和表面络合作用是ZIFs@MXene高吸附能力的作用机理.本研究为高性能吸附材料的构建以及海水中铀的提取提供了理论指导. 展开更多
关键词 MXene UO_(2)(CO_(3))_(2)^(2-) ZIF-8 ZIF-67 吸附作用 表面络合
原文传递
层状双金属氧化物材料对放射性核素的去除研究 被引量:13
4
作者 王祥学 庞宏伟 +4 位作者 吴忆涵 于淑君 宋刚 马宵颖 许佩瑶 《中国科学:化学》 CAS CSCD 北大核心 2019年第1期2-11,共10页
层状双金属氧化物材料(LDHs)作为最常见的二维材料,在环境污染治理领域展现出巨大的优势. LDHs具有来源广泛、易于制备、较大的表面积、可调控的化学结构、环境友好等优点,最近几年其改性材料多用于放射性核素的高效去除.本文介绍了常用... 层状双金属氧化物材料(LDHs)作为最常见的二维材料,在环境污染治理领域展现出巨大的优势. LDHs具有来源广泛、易于制备、较大的表面积、可调控的化学结构、环境友好等优点,最近几年其改性材料多用于放射性核素的高效去除.本文介绍了常用的LDHs材料及其衍生物的制备方法以及它们在放射性核素处理方面的应用及其相互作用机制,最后对LDHs材料的应用和挑战给出了个人见解.本综述为高效去除放射性核素的LDHs材料的设计指明了方向,为放射性核素的高效处理处置提供了新材料. 展开更多
关键词 双金属氧化物材料 放射性核素 吸附 分析表征 作用机理
原文传递
石墨相氮化碳材料在水环境污染物去除中的研究 被引量:12
5
作者 刘玥 吴忆涵 +3 位作者 庞宏伟 王祥学 于淑君 王祥科 《化学进展》 SCIE CAS CSCD 北大核心 2019年第6期831-846,共16页
水污染是世界性问题,严重影响了人类的身体健康和环境的可持续性。迫切需要一种高效环保的吸附剂材料用于水体污染治理。石墨相氮化碳(g-C3N4)材料具有与石墨类似的层状结构,具有许多优异性质,如大的表面积、高的热稳定性和化学惰性,成... 水污染是世界性问题,严重影响了人类的身体健康和环境的可持续性。迫切需要一种高效环保的吸附剂材料用于水体污染治理。石墨相氮化碳(g-C3N4)材料具有与石墨类似的层状结构,具有许多优异性质,如大的表面积、高的热稳定性和化学惰性,成为新兴的吸附剂材料。本文主要介绍了g-C3N4基材料在重金属、放射性核素以及有机污染物去除方面的应用。通过批实验、光谱分析、表面配位模型和理论计算等技术系统分析了g-C3N4基材料与污染物之间的作用机理。g-C3N4基材料与污染物之间的相互作用主要归因于表面配位、π-π作用、离子交换作用和静电作用。本文有助于读者进一步了解g-C3N4基材料与污染物之间的作用机理,并且发掘更多的g-C3N4改性材料,将其应用于环境修复领域当中。 展开更多
关键词 氮化碳 重金属 放射性核素 有机污染物 反应机理
原文传递
Synthesis of rod-like metal-organic framework(MOF-5)nanomaterial for efficient removal of U(Ⅵ):batch experiments and spectroscopy study 被引量:22
6
作者 Yihan Wu Hongwei Pang +4 位作者 Wen Yao xiangxue wang Shujun Yu Zhimin Yu Xiangke wang 《Science Bulletin》 SCIE EI CSCD 2018年第13期831-839,共9页
With the widespread application of radionuclide235 U(Ⅵ), it is inevitable that part of U(Ⅵ) is released into the natural environment. The potential toxicity and irreversibility impact on the natural environment has ... With the widespread application of radionuclide235 U(Ⅵ), it is inevitable that part of U(Ⅵ) is released into the natural environment. The potential toxicity and irreversibility impact on the natural environment has become one of the most forefront pollution problems in nuclear energy utilization. In this work, rod-like metal-organic framework(MOF-5) nanomaterial was synthesized by a solvothermal method and applied to efficiently adsorb U(Ⅵ) from aqueous solutions. The batch experimental results showed that the sorption of U(Ⅵ) on MOF-5 was strongly dependent on p H and independent of ionic strength, indicating that the dominant interaction mechanism was inner-sphere surface complexation and electrostatic interaction. The maximum sorption capacity of U(Ⅵ) on MOF-5 was 237.0 mg/g at p H 5.0 and T = 298 K, and the sorption equilibrium reached within 5 min. The thermodynamic parameters indicated that the removal of U(Ⅵ) on MOF-5 was a spontaneous and endothermic process. Additionally, the FT-IR and XPS analyses implied that the high sorption capacity of U(Ⅵ) on MOF-5 was mainly attributed to the abundant oxygen-containing functional groups(i.e., CAO and C@O). Such a facile preparation method and efficient removal performance highlighted the application of MOF-5 as a candidate for rapid and efficient radionuclide contamination's elimination in practical applications. 展开更多
关键词 移动性能 框架 器官 金属 光谱学 批实验 放射性核种 合成
原文传递
Application of graphene oxides and graphene oxide-based nanomaterials in radionuclide removal from aqueous solutions 被引量:17
7
作者 xiangxue wang Shujun Yu +5 位作者 Jie Jin Hongqing wang Njud S. Alharbi Ahmed Alsaedi Tasawar Hayat Xiangke wang 《Science Bulletin》 SCIE EI CAS CSCD 2016年第20期1583-1593,共11页
With the fast development of nanoscience and nanotechnology,the nanomaterials have attracted multidisciplinary interests.The high specific surface area and large numbers of oxygen-containing functional groups of graph... With the fast development of nanoscience and nanotechnology,the nanomaterials have attracted multidisciplinary interests.The high specific surface area and large numbers of oxygen-containing functional groups of graphene oxides(GOs) make them suitable in the preconcentration and solidification of radionuclides from wastewater.In this paper,mainly based on the recent work carried out in our laboratory,the efficient elimination of radionuclides using GOs and GO-based nanomaterials as adsorbents are summarized and the interaction mechanisms are discussed from the results of batch techniques,surface complexation modeling,spectroscopic analysis and theoretical calculations.This review is helpful for the understanding of the interactions of radionuclides with GOs and GO-based nanomaterials,which is also crucial for the application of GOs and GO-based nanomaterials in environmental radionuclide pollution management and also helpful in nuclear waste management. 展开更多
关键词 Graphene oxides Radionuclides SORPTION Interaction mechanism Theoretical calculation Spectroscopic analysis
原文传递
Synthesis of novel nanomaterials and their application in efficient removal of radionuclides 被引量:20
8
作者 xiangxue wang Long Chen +15 位作者 Lin wang Qiaohui Fan Duoqiang Pan Jiaxing Li Fangting Chi Yi Xie Shujun Yu Chengliang Xiao Feng Luo Jun wang Xiaolin wang Changlun Chen wangsuo Wu Weiqun Shi Shuao wang Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2019年第8期933-967,共35页
With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment... With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment. Nanomaterials have been considered as the potential candidates for the effective and selective removal of radionuclides from aqueous solutions under complicated conditions because of their high specific surface area, large amounts of binding sites, abundant functional groups, pore-size controllable and easily surface modification. This review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides,and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations. The sorption capacities with other materials, advantages and disadvantages of different nanomaterials are compared, and at last the perspective of the novel nanomaterials is summarized. 展开更多
关键词 NANOMATERIALS radionuclides REMOVAL PRECONCENTRATION INTERACTION MECHANISM
原文传递
One-pot synthesis of graphene oxide and Ni-Al layered double hydroxides nanocomposites for the efficient removal of U(VI) from wastewater 被引量:12
9
作者 Shujun Yu Jian wang +5 位作者 Shuang Song Kunyu Sun Jun Li xiangxue wang Zhongshan Chen Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第3期415-422,共8页
Graphene oxide and Ni-Al layered double hydroxides(GO@LDH) nanocomposites were synthesized via a one-pot hydrothermal process,and characterized by X-ray diffraction(XRD),Fourier transformed infrared spectroscopy(FTIR)... Graphene oxide and Ni-Al layered double hydroxides(GO@LDH) nanocomposites were synthesized via a one-pot hydrothermal process,and characterized by X-ray diffraction(XRD),Fourier transformed infrared spectroscopy(FTIR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy in detail.The exploration of U(VI) sorption on GO@LDH surface was performed as a function of ionic strength,solution pH,contact time,U(VI) initial concentrations and temperature.Results of Langmuir isotherms showed that the sorption capacity of GO@LDH(160 mg/g) was much higher than those of LDH(69 mg/g) and GO(92 mg/g).The formed surface complexes between surface oxygen-containing functional groups of GO@LDH and U(VI) turned out to be the interaction mechanism of U(VI) with GO@LDH.According to the thermodynamic studies results,the sorption interaction was actually a spontaneous and endothermic chemical process.The sorption isotherms were better fitted with the Langmuir model compared with other models,which suggested the interaction was mainly dominated by mono layer coverage.The GO@LDH nanocomposites provide potential applications as adsorbents in the enrichment of radionuclides from wastewater in nuclear waste management and environmental remediation. 展开更多
关键词 GO GO@LDH U(Ⅵ) interaction mechanism SORPTION
原文传递
In-situ reduction synthesis of manganese dioxide@polypyrrole core/shell nanomaterial for highly efficient enrichment of U(Ⅵ) and Eu(Ⅲ) 被引量:8
10
作者 Wen Yao Yihan Wu +3 位作者 Hongwei Pang xiangxue wang Shujun Yu Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2018年第7期812-823,共12页
Radionuclides with long half-life are toxic,and thereby result in serious threat to human beings and ecological balance.Herein,a simple two-step synthesis method was used to prepare manganese dioxide@polypyrrole(Mn O_... Radionuclides with long half-life are toxic,and thereby result in serious threat to human beings and ecological balance.Herein,a simple two-step synthesis method was used to prepare manganese dioxide@polypyrrole(Mn O_2@PPy)core/shell structures for efficient removal of U(Ⅵ)and Eu(Ⅲ)from aqueous solutions.The adsorption of U(Ⅵ)and Eu(Ⅲ)were investigated under different kinds of experimental conditions.The experimental results suggested that the adsorption of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy were greatly affected by p H.U(Ⅵ)adsorption on Mn O_2@PPy was independent of ionic strength at p H<6.0,and dependent on ionic strength at p H>6.0.However,Eu(Ⅲ)adsorption on Mn O_2@PPy was independent of ionic strength at the whole p H range of experimental conditions.The maximum adsorption capacities(q_(max))of U(Ⅵ)and Eu(Ⅲ)were 63.04 and54.74 mg g^(-1)at T=298 K,respectively.The BET,XRD,FTIR and XPS analysis evidenced that high adsorption capacities of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy were mainly due to high surface area and rich metal oxygen-containing group(i.e.,Mn–OH and Mn–O),and the interaction was mainly attributed to strong surface complexation and electrostatic interaction.This study highlighted the excellent adsorption performance of U(Ⅵ)and Eu(Ⅲ)on Mn O_2@PPy and could provide the reference for the elimination of radionuclides in real wastewater management. 展开更多
关键词 合成方法 EU 放射性核种 试验性 半衰期 Mn 吸附
原文传递
Ozonated graphene oxides as high efficient sorbents for Sr(Ⅱ) and U(Ⅵ) removal from aqueous solutions 被引量:6
11
作者 Xia Liu xiangxue wang +1 位作者 Jiaxing Li Xiangkewang 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第7期869-877,共9页
Ozone was used to oxidize graphene oxides(GO) to generate ozonated graphene oxides(OGO) with higher oxygen-containing functional groups. The as-prepared OGO was characterized by Fourier transformed infrared spectrosco... Ozone was used to oxidize graphene oxides(GO) to generate ozonated graphene oxides(OGO) with higher oxygen-containing functional groups. The as-prepared OGO was characterized by Fourier transformed infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). Based on the results of potentiometric acid-base titrations, the total carboxylic acid concentration on OGO surface was calculated to be 3.92 mmol/g, which was much higher than that on GO surface. The results of adsorption experiments indicated that the adsorption capacities of OGO for Sr(II) and U(VI) removal were improved significantly after ozonization. 展开更多
关键词 氧化石墨 氧化物 VI 水溶液 吸附剂 傅里叶变换红外光谱 X射线光电子能谱 扫描电子显微镜
原文传递
Graphene oxides for simultaneous highly efficient removal of trace level radionuclides from aqueous solutions 被引量:5
12
作者 xiangxue wang Zhongshan Chen Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第11期1766-1773,共8页
Graphene oxides(GOs) were synthesized via modified Hummers method, and were applied as adsorbents to remove radionuclides from large volumes of aqueous solutions. The single and competitive sorption of four radionucli... Graphene oxides(GOs) were synthesized via modified Hummers method, and were applied as adsorbents to remove radionuclides from large volumes of aqueous solutions. The single and competitive sorption of four radionuclides(i.e., U(VI), 152+154Eu(III), 85+89Sr(II) and 134Cs(I)) on the GOs from aqueous solutions were investigated as a function of p H, ionic strength and radionuclide initial concentrations using batch technique. The results showed that the GOs had much higher sorption capacity than many other contemporary materials, for the preconcentration of radionuclides from large volumes of aqueous solutions. The sorption of radionuclides on GOs obeyed the Langmuir model, and was mainly attributed to surface complexation via the coordination of radionuclides with the oxygen-containing functional groups on GO surfaces. The competitive sorption results indicated that the selectivity sorption capacities were U(VI)>Eu(III)>Sr(II)>Cs(I). The GOs are suitable materials for the efficient removal and preconcentration of radionuclides from aqueous solutions in nuclear waste management and environmental pollution cleanup. 展开更多
关键词 放射性核素 水溶液 氧化物 石墨 痕量 吸附能力 现代材料 表面络合
原文传递
磁性竹荪生物炭材料对水中铀的高效去除与机理 被引量:5
13
作者 刁卓凡 庞宏伟 +3 位作者 唐昊 王祥学 于淑君 宋刚 《科学通报》 EI CAS CSCD 北大核心 2020年第34期3954-3964,共11页
核工业发展所消耗的核燃料会不可避免地将大量含铀(U(VI))废水排放到自然界,给生态和环境带来一定的威胁,因而去除水环境中的U(VI)成为一项迫切的任务.本研究通过水热法制备了磁性竹荪生物炭材料(magneticdictyophora indusiata derived... 核工业发展所消耗的核燃料会不可避免地将大量含铀(U(VI))废水排放到自然界,给生态和环境带来一定的威胁,因而去除水环境中的U(VI)成为一项迫切的任务.本研究通过水热法制备了磁性竹荪生物炭材料(magneticdictyophora indusiata derived biochar,M-DI)并将其用于水溶液中U(VI)的高效去除.利用光谱分析表征其微观结构,证明了目标材料的成功制备和其良好的理化性质.通过宏观试验探究了反应时间、温度、pH、离子强度等因素对M-DI复合材料去除U(VI)的影响,并综合讨论其去除机理.结果表明,M-DI复合材料对U(VI)的吸附过程在30 min内达到平衡,吸附行为符合Langmuir模型,最大吸附量达到122.8 mg g−1,去除机理为受静电作用影响的内层表面配位作用,且在吸附完成后在外加磁场作用下易进行固液分离.M-DI复合材料对U(VI)优异的去除效果显示了其在放射性核废水净化方面的巨大潜力. 展开更多
关键词 生物炭 四氧化三铁 U(VI) 吸附 去除机理
原文传递
硫化纳米零价铁对水中U(Ⅵ)的高效去除研究 被引量:4
14
作者 白子昂 陈瑞兴 +3 位作者 庞宏伟 王祥学 宋刚 于淑君 《化学学报》 SCIE CAS CSCD 北大核心 2021年第10期1265-1272,共8页
近年来,放射性污染物铀(U(Ⅵ))在水环境中的排放对生态环境和生物健康造成严重的威胁.本研究采用液相还原法制备了硫化纳米零价铁(S-NZⅥ)材料,并将其用于水中U(Ⅵ)的去除.首先,我们采取了一系列的微观表征技术探究了S-NZⅥ的表面特征... 近年来,放射性污染物铀(U(Ⅵ))在水环境中的排放对生态环境和生物健康造成严重的威胁.本研究采用液相还原法制备了硫化纳米零价铁(S-NZⅥ)材料,并将其用于水中U(Ⅵ)的去除.首先,我们采取了一系列的微观表征技术探究了S-NZⅥ的表面特征及材料特性.结果表明,相比于纳米零价铁(NZⅥ), S-NZⅥ颗粒不易团聚,性质更加稳定.随后,通过宏观实验探究了反应时间、温度、p H、背景离子浓度等因素对S-NZⅥ去除U(Ⅵ)的影响.结果表明, S-NZⅥ对U(Ⅵ)的最大去除量高达562.5 mg·g-1,且在100 min内达到反应平衡.宏观实验和X射线光电子能谱(XPS)分析表明S-NZⅥ对U(Ⅵ)的去除机理是吸附和氧化还原协同作用的结果.此外, S-NZⅥ可以通过外加磁场从水中快速地进行分离,便于材料再回收与利用.综上,本研究构筑了一种制备简单、便于回收且高效的U(Ⅵ)净化材料,未来可能会在放射性核素的处理处置等相关工作中起到重要作用. 展开更多
关键词 U(Ⅵ) 硫化纳米零价铁 吸附 氧化还原 协同作用
原文传递
Interaction of radionuclides with natural and manmade materials using XAFS technique 被引量:3
15
作者 Shujun Yu xiangxue wang +4 位作者 Shitong Yang Guodong Sheng Ahmed Alsaedi Tasawar Hayat Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第2期170-187,共18页
The X-ray absorption fine structure(XAFS)technology has exhibited a very unique application in the study of sorption mechanism,chemical species and microstructures of radionuclides at the natural solid-water interface... The X-ray absorption fine structure(XAFS)technology has exhibited a very unique application in the study of sorption mechanism,chemical species and microstructures of radionuclides at the natural solid-water interfaces.In this review,the interaction mechanism of radionuclides with clay minerals and nanomaterials under different environmental conditions are summarized from the XAFS spectroscopy analysis.The coordination number and the bond distances of radionuclides,the oxidation-reduction reactions,the influence of humic substances and microorganisms on the species and structures of radionuclides at molecule level are reviewed and compared.This review is helpful to understand the interactions of radionuclides with oxides,natural clay minerals and nanomaterials,which is also crucial to evaluate the physicochemical behaviors of radionuclides in the natural environment. 展开更多
关键词 放射性核素 XAFS 纳米材料 自然环境 相互作用 X射线吸收精细结构 技术 氧化还原反应
原文传递
酸化氧化生物炭在含铀放射性废水处理中的应用研究 被引量:5
16
作者 宋爽 顾鹏程 +3 位作者 陈中山 王祥学 张瑞 文涛 《中国科学:化学》 CAS CSCD 北大核心 2019年第1期155-164,共10页
随着核工业的发展,大量放射性污染物被排放到环境中,严重威胁着人类健康.生物炭材料作为一种可再生资源,具有丰富的孔隙结构和独特的表面化学性质,因此被广泛地应用于环境中污染物的去除.本文分别用煅烧处理后的咖啡渣(CG)和硝酸氧化后... 随着核工业的发展,大量放射性污染物被排放到环境中,严重威胁着人类健康.生物炭材料作为一种可再生资源,具有丰富的孔隙结构和独特的表面化学性质,因此被广泛地应用于环境中污染物的去除.本文分别用煅烧处理后的咖啡渣(CG)和硝酸氧化后的咖啡渣(CG-AO)作为生物炭吸附剂,研究了它们在模拟含铀废水中对U(Ⅵ)的去除性能,探究了溶液pH、反应时间、U(Ⅵ)的初始浓度、反应温度等因素对溶液中U(Ⅵ)去除率的影响,并通过X射线光电子能谱(XPS)光谱分析了相应的吸附机理.结果表明, pH对U(Ⅵ)在CG和CG-AO上的吸附效果影响显著,在近中性p H范围内表现出最佳的吸附效果;吸附反应能很快达到平衡,准二级动力学方程能够很好地拟合吸附动力学过程; Langmuir模型能较好地描述CG-AO对U(Ⅵ)的等温吸附过程,吸附容量与温度呈正相关;室温下改性得到生物炭材料对U(Ⅵ)的饱和吸附量约为251.71 mg g^(-1),几乎是未改性前生物炭的3倍(80.93 mg g^(-1)).基于XPS光谱分析发现, CG-AO对U(Ⅵ)的吸附机理可能是通过羧基与U(Ⅵ)形成表面配合物(O=C–O)_2UO_2,而CG则可能是通过羧基与水的协同作用与U(Ⅵ)形成表面配合物O=C–OUO_2(OH). 展开更多
关键词 U(VI) 生物炭 光谱分析 吸附机理
原文传递
One-pot synthesis of arginine modified hydroxyapatite carbon microsphere composites for efficient removal of U(Ⅵ) from aqueous solutions 被引量:3
17
作者 Dongxu Yang xiangxue wang +6 位作者 Gang Song Guixia Zhao Zhe Chen Shujun Yu Pengcheng Gu Hongqing wang Xiangke wang 《Science Bulletin》 SCIE EI CAS CSCD 2017年第23期1609-1618,共10页
Uranium was not only the main source of nuclear energy but also one of the long-lived radionuclide.Herein, a novel arginine modified hydroxyapatite carbon microsphere composites(defined as C@HAp/Arg) obtained promptly... Uranium was not only the main source of nuclear energy but also one of the long-lived radionuclide.Herein, a novel arginine modified hydroxyapatite carbon microsphere composites(defined as C@HAp/Arg) obtained promptly via a one-step mild hydrothermal method, was applied to remove U(Ⅵ) from aqueous solutions. Based on the characterization of transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transformed infrared spectroscopy(FT-IR), X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS), the synthesized C@HAp/Arg presented globular morphology and abundant functional groups(e.g., —COO^-), which were beneficial to its combination with U(Ⅵ). The interaction mechanism and removal capability of U(Ⅵ) on C@HAp/Arg were studied by batch adsorption technique and spectroscopy analysis. The results implied that U(Ⅵ) can form strong surface complexes on C@HAp/Arg. The kinetics adsorption of U(Ⅵ) followed pseudo-second-order kinetic model with high removal efficiency($95% within 5h at pH 5.0). The adsorption isotherms were well fitted by Langmuir model, implying that U(Ⅵ) uptake on C@HAp/Arg was monolayer coverage. It was found that the maximum adsorption capacities of CSs, C@HAp and C@HAp/Arg toward U(Ⅵ) were calculated to be 23.16,72.09 and 569.66 mg/g, respectively, at 298.15 K and pH 5.0, and thermodynamic parameters revealed that the adsorption processes of U(Ⅵ) were spontaneous and endothermic. In addition, effect of co-existed ions and CO_3^(2-)concentrations demonstrated that U(Ⅵ) adsorption on C@HAp/Arg was weakly interfered by foreign ions and carbonate concentrations. More importantly, the adsorption performance of U(Ⅵ) on C@HAp/Arg was still over $87% after five cycles. Therefore, it was noted that the versatile C@HAp/Arg could be potentially used as a powerful building block for the enrichment and disposal of U(Ⅵ) from aqueous solutions, which could efficiently reduce the potential toxicity of U(Ⅵ) in the U(Ⅵ)-contaminated water. 展开更多
关键词 U(Ⅵ) C@HAp/Arg composites Interaction mechanism Adsorption
原文传递
氰基改性UiO-66的合成及其对Eu(Ⅲ)的去除性能及机理研究 被引量:2
18
作者 李碧云 吴忆涵 +3 位作者 唐昊 王祥学 于淑君 宋刚 《中国科学:化学》 CAS CSCD 北大核心 2020年第8期936-944,共9页
UiO-66作为一种较为稳定的金属有机框架材料,由于其良好的吸附能力和可修饰性,成为高效去除放射性核素的新兴材料.在UiO-66框架中引入不同的官能团,可以有效地改善材料本身的物理化学性能.本文利用微波辐射法通过在UiO-66-Br上引入氰基(... UiO-66作为一种较为稳定的金属有机框架材料,由于其良好的吸附能力和可修饰性,成为高效去除放射性核素的新兴材料.在UiO-66框架中引入不同的官能团,可以有效地改善材料本身的物理化学性能.本文利用微波辐射法通过在UiO-66-Br上引入氰基(C≡N)官能团制备了UiO-66-CN,并将其用于Eu(Ⅲ)的去除研究.采用静态吸附实验和微观表征技术(如扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)和X射线光电子能谱(XPS)等)研究了UiO-66-CN对Eu(Ⅲ)的吸附行为和作用机制.表征结果显示,UiO-66-CN具有良好的稳定性和丰富的官能团,其表面丰富的氰基和含氧官能团使其能够与Eu(Ⅲ)以静电作用和表面配合等方式结合.此外,静态吸附实验表明, UiO-66-CN对Eu(Ⅲ)的吸附行为符合准二级动力学模型和Langmuir等温线模型.在298、313、328 K时UiO-66-CN对Eu(Ⅲ)的最大吸附量可分别达到138.9、149.4和155.8 mg g-1.经过6次循环再生之后, UiO-66-CN仍具有较高的去除效率,表明UiO-66-CN材料具有良好的循环使用性能.研究表明, UiO-66-CN具有优异的稳定性,对Eu(Ⅲ)有着强的吸附能力,能够有效地从废水中捕获Eu(Ⅲ). 展开更多
关键词 UiO-66 MOF 吸附 Eu(Ⅲ) 作用机理
原文传递
Erratum on “Complexation of radionuclide 152+154Eu(Ⅲ) with alumina-bound fulvic acid studied by batch and time-resolved laser fluorescence spectroscopy” [Sci. China Chem., 2017, 60: 107–114] 被引量:1
19
作者 xiangxue wang Shujun Yu +7 位作者 Zhongshan Chen Wencheng Song Yuantao Chen Tasawar Hayat Ahmed Alsaedi Wei Guo Jun Hu Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2019年第12期1732-1733,共2页
In the above referenced publication[1],the Figure 5 and data in Table 1 are correct,but we ignored to present the final pH values of the system,which is very important to understand the properties.
关键词 properties. Figure BATCH
原文传递
Microstructures and speciation of radionuclides in natural environment studied by advanced spectroscopy and theoretical calculation 被引量:1
20
作者 xiangxue wang Shujun Yu +3 位作者 Zhongshan Chen Yushan Zhao Jie Jin Xiangke wang 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第9期1149-1152,共4页
The environmental behavior of radionuclides is mainly dependent on their speciation and microstructures at solid particles.The speciation and microstructures of radionuclides at molecular level can be achieved from ad... The environmental behavior of radionuclides is mainly dependent on their speciation and microstructures at solid particles.The speciation and microstructures of radionuclides at molecular level can be achieved from advanced spectroscopy techniques and theoretical calculations.In this perspective,we give a brief introduction of the advanced X-ray absorption fine structure(XAFS) technique and theoretical calculation in the analysis of the speciation and microstructures of radionuclides in the natural environment,which is crucial to evaluate the physicochemical behavior of radionuclides in the environment. 展开更多
关键词 中国科学 化学英文版
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部