检索结果-南通市图书馆

高温、高压和pH值多种因素作用下蒙脱石层间Cs^(+)/UO_(2)^(2+)水化和扩散行为的分子模拟

在线全文

学校读者我要写书评

暂无评论

原子能科学技术 2022年第7期56卷 1243-1250页

作者：李楠王进王军霞孙鸿昊王丽丽西南科技大学材料科学与工程学院四川绵阳621010 北京应用物理与计算数学研究所北京100094

作为核废物地质处置库缓冲回填材料的主要成分,蒙脱石在特殊环境(高温、高压和pH多种因素作用)下吸附阻滞核素的行为对缓冲回填材料的性能评估至关重要。为从微观分子尺度探究特殊环境下蒙脱石层间核素离子的吸附扩散行为,本文采用蒙特... 详细信息

作为核废物地质处置库缓冲回填材料的主要成分,蒙脱石在特殊环境(高温、高压和pH多种因素作用)下吸附阻滞核素的行为对缓冲回填材料的性能评估至关重要。为从微观分子尺度探究特殊环境下蒙脱石层间核素离子的吸附扩散行为,本文采用蒙特卡罗(MC)和分子动力学(MD)方法,分别研究了Cs^(+)/UO_(2)^(2+)在蒙脱石层间的吸附行为,以及高温、高压和pH值多种因素作用下的水化和扩散动力特征。MC结果表明:蒙脱石层间的Cs^(+)、UO_(2)^(2+)周围分别会形成1层和2层水化壳,且层间水分子与四面体中氧原子之间形成了明显的氢键;当c=1.25 nm时,蒙脱石层间最多可吸附285个水分子。MD结果表明:高温、高压和pH值都会对Cs^(+)、UO_(2)^(2+)的水化和扩散产生影响。常温、常压下pH值分别为11.85、12.15时,Cs^(+)、UO_(2)^(2+)水化壳中的水分子数最多;pH值分别为12.15、11.85时,Cs^(+)、UO_(2)^(2+)的扩散系数最大,分别为5.31×10^(-13)m^(2)/s和1.11×10^(-12)m^(2)/s。与常温、常压相比,高温、高压下Cs^(+)、UO_(2)^(2+)水化壳中的水分子数最多时,pH值分别为7.00、12.15;而Cs^(+)、UO_(2)^(2+)扩散系数最大(1.12×10^(-12)m^(2)/s、1.01×10^(-12)m^(2)/s)时的pH值均为12.15。

关键词： Cs^(+)/UO_(2)^(2+)-蒙脱石高温高压 pH值吸附扩散分子模拟

On-site rapid detection of multiple pesticide residues in tea leaves by lateral flow immunoassay

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第2期14卷 276-283页

作者： junxia Gao Tianyi Zhang Yihua Fang Ying Zhao Mei Yang Li Zhao Ye Li Jun Huang Guonian Zhu Yirong Guo Institute of Pesticide and Environmental Toxicology Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang ProvinceMinistry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and InsectsZhejiang UniversityHangzhou310058China Tea Research Institute Chinese Academy of Agricultural SciencesKey Laboratory of Tea Biology and Resources UtilizationMinistry of AgricultureHangzhou310008China Shanghai Agricultural Technology Extension Service Center Shanghai201103China School of Biological and Chemical Engineering Zhejiang University of Science and TechnologyHangzhou311200China

The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.

关键词： Lateral flow immunoassay Rapid detection Pesticide multi-residue Tea matrix Sample rapid pretreatment

Degradation Behavior of Ti-6Al-4V Alloys for Dental Applications in Acidic Artificial Saliva Containing Fluoride Ion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2017年第4期32卷 926-934页

作者：杨丽霞 HAO Shuo ZHU Qiliang XIA Dahai wang junxia ZHANG Junfeng MA Jingzhi WEI wei School of Material and Chemistry China University of Geosciences Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and Engineering Tianjin University Department of Stomatology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology

The aim of this work was to study the degradation behavior of Ti-6Al-4V alloys for dental applications in acidic artificial saliva with fluoride ion using electrochemical techniques, optical microscopy, scanning electron microscopy（SEM）, and energy dispersive spectrometry（EDS）. The experimental results showed that fluoride ion had significant influence on the degradation of Ti-6Al-4V alloys, and there was an obvious critical concentration of fluoride ion（about 0.1wt%）. With increasing fluoride ion concentration, the corrosion potential（Ecorr） of alloys moved toward negative and the impedance of alloys decreased, meanwhile, noticeable transformation from minimum corrosion to severe pitting corrosion was observed on alloys surface following the dissolution of TiO2 passive films, leading to the decrease of the corrosion resistance of alloys. The electrochemical dissolution of TiO2 passive films involved a nucleophilic attack of fluoride atom to the titanium atom of TiO2. In addition, Ca^（2＋）and Na~＋ in acidic saliva may involve the surface reactions and make the reactions more complex.

关键词： alloy corrosion scanning electron microscopy（SEM） passive films

Roles of Phe58 residue in stabilizing structure of cytochrome b_5

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第24期47卷 2063-2066页

作者： wang Yunhua, LU junxia, wang Wenhu, REN Yi, XIE Yi & HUANG ZhongxianDepartment of Chemistry, Fudan University, Shanghai 200433, China Department of Chemistry Fudan University Shanghai China

To understand effect of π-stacking interactions between the side chain of aromatic amino acids and the por-phyrin ring on structures and properties in cytochrome b5 (cyt b5), the Phe58 residue was mutated to tyrosine and tryptophan, respectively by site-directed mutagenesis. The denaturation of cyt bs F58W and F58Y toward guanidine hydrochloride was examined by UV-visible and fluorescence spectroscopy. The kinetics of heme transfer reactions between apo-myoglobin and the mutants were studied. The results indicated that the mutation of F58 residue for Y58 or W58 reduced the interaction between of peptide and the heme group, resulting in decrease of the Tm and Cm values of the proteins, increase of the heme transfer reaction rate, and shifts of the redox potential.

关键词： cytochrome b5 aromatic stacking heme-peptide interaction mutation structural stability

NZP型磷酸盐陶瓷固化模拟放射性核素Sr^(2+)/Sm^(3+)的研究

在线全文

学校读者我要写书评

暂无评论

材料导报 2022年第1期36卷 60-64页

作者：张雪王进罗萍刘蝶詹磊魏玉锋王军霞西南科技大学材料科学与工程学院四川绵阳621010

本工作以Sr^(2+)和Sm^(3+)分别模拟二价裂变核素和三价次锕系核素,利用NaZr_(2)(PO_(4))_(3)(NZP)结构丰富的离子取代性同时固化多种模拟放射性核素,采用微波烧结工艺在1100℃保温2 h制备了固溶Sr、Sm的NZP型磷酸盐陶瓷固化体(Na,Sr)(Zr... 详细信息

本工作以Sr^(2+)和Sm^(3+)分别模拟二价裂变核素和三价次锕系核素,利用NaZr_(2)(PO_(4))_(3)(NZP)结构丰富的离子取代性同时固化多种模拟放射性核素,采用微波烧结工艺在1100℃保温2 h制备了固溶Sr、Sm的NZP型磷酸盐陶瓷固化体(Na,Sr)(Zr,Sm)_(2)(PO_(4))_(3),系统地研究了Sr/Sm掺入量对固化体的物相组成、微观形貌、表观密度以及维氏硬度的影响规律。研究结果表明:Sr能够完全固溶进入NZP结构的Na晶格位形成Sr_(0.5)-Zr_(2)(PO_(4))_(3)(SrZP),而Sm难以进入NZP的Zr晶格位,掺入的Sm主要以SmPO_(4)独居石的形式存在。固溶Sr/Sm的陶瓷固化体结构致密,晶粒大小均匀,且SmPO_(4)独居石的存在不会降低固化体的致密性和力学性能;随着Sm掺入量的增加,样品的表观密度和维氏硬度逐渐增大,最大值分别为3.61 g·cm^(-3)和679 MPa。同时,PCT浸出结果表明所制备的样品具有良好的化学稳定性,各元素的归一化浸出率均处于10^(-3)~10^(-7) g·m^(-2)·d^(-1)。

关键词：磷酸锆钠(NZP) 固化放射性核素独居石微波烧结

Double-Display for High-efficient Peptide Evolution

在线全文

学校读者我要写书评

暂无评论

Double-Display for High-efficient Peptide Evolution

人工智能、制造业创新链与经济高质量发展--基于地区面板数据的实证研究

第十一届全国化学生物学学术会议

作者： junxia wang Yuyu Tan Jiajun Ling Mingxia Zhang Wenli Liu Mengjiao Huang Yanling Song Zhi Zhu Chaoyong Yang Department of Chemical Biology College of Chemistry and Chemical EngineeringXiamen University Department of Biomedical Engineering School of Electrical EngineeringUniversity of South China Institute of Molecular Medicine Renji HospitalShanghai Jiao Tong University School of Medicine

Phage display for peptide evolution suffered from amplification bias and incompatible throughputs between screening and characterization,which could lose low-abundant but higher-affinity sequences.To solve these problems,we proposed a high-efficient droplet microfluidic based Double-Display to obtain specific peptides within the same throughput for screening and characterization a whole enriched phage library.By enclosing single phage and target-coated beads into droplets,monoclonal phages were cultured and the specific phages could bind to target-coated beads inside the droplets.The unbound phages were washed away by washing buffer.By staining the phage with fluorescent dye,the positive clones can be easily picked out through the fluorescence signal,followed by amplification and sequencing to obtain peptide sequence.Basic process of screening and characterization were integrated to realize high-efficient evolution in 24 hr.Droplets allowed the restrain of growth-advantage.Besides,only the highest-affinity phages were selected among the whole library（～105 clones）,instead of random picking of less than 200 clones for characterization.We have evolved the specific peptide against protein CD71 and glycoprotein GPC1 by Double-Display,which were experimentally proved to be covered in bulk amplification,proving its generality to find the growth-disadvantage but high-affinity sequences.Thus,Double-Display is a rapid,high-efficiency,high-throughput peptide evolution platform,which would promote the development of precision medicine.

关键词： Phage display peptide evolution droplet microfluidics

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

科技管理研究 2023年第7期43卷 171-181页

作者：周松兰王俊霞林熙广州大学经济与统计学院广东广州510006

基于中国2006—2019年28个省份的面板数据,构建中介效应模型,以制造业创新链作为中介渠道,分析人工智能对地区经济高质量发展的影响。研究发现,人工智能对各省份经济高质量发展有显著的促进作用,制造业创新链在其中发挥重要的中介作用... 详细信息

基于中国2006—2019年28个省份的面板数据,构建中介效应模型,以制造业创新链作为中介渠道,分析人工智能对地区经济高质量发展的影响。研究发现,人工智能对各省份经济高质量发展有显著的促进作用,制造业创新链在其中发挥重要的中介作用。与中西部地区相比,人工智能对东部地区的创新链发展的促进作用更强;与2013年以及之后相比,人工智能的单位变化在2013年以及之前的时期对经济高质量发展的促进作用更强。此外,人工智能主要通过制造业创新链的投入和产出环节,促进地区经济高质量发展,而市场应用环节的中介作用并不显著。

关键词：人工智能制造业创新链经济高质量发展面板数据

微波法制备磷酸化石墨烯@CoFe_(2)O_(4)及其对氟喹诺酮类抗生素的吸附

在线全文

学校读者我要写书评

暂无评论

环境化学 2022年第11期41卷 3705-3715页

作者：任雪高仕谦王俊霞王振峰张占恩苏州科技大学环境科学与工程学院苏州215009 温州医科大学公共卫生与管理学院温州325035

本研究通过微波法制备了磷酸功能化磁性石墨烯(PG@CoFe_(2)O_(4))材料,并用其吸附水中6种氟喹诺酮类抗生素(FQs).采用扫描电镜、透射电镜、X射线衍射、磁滞回线等对复合材料进行系统的表征.系统考察了Cl^(-)、HCO_(3)^(-)/SO_(4)^(2-)... 详细信息

本研究通过微波法制备了磷酸功能化磁性石墨烯(PG@CoFe_(2)O_(4))材料,并用其吸附水中6种氟喹诺酮类抗生素(FQs).采用扫描电镜、透射电镜、X射线衍射、磁滞回线等对复合材料进行系统的表征.系统考察了Cl^(-)、HCO_(3)^(-)/SO_(4)^(2-)和腐殖酸(HA)等对FQs吸附的影响.实验结果显示,在pH=4.0的情况下,PG@CoFe_(2)O_(4)投加量20.0 mg,30 min内6种目标物的去除率最高可达到95.5%.低浓度促进吸附而高浓度则抑制吸附,HCO_(3)^(-)/SO_(4)^(2-)和HA几乎不影响吸附过程,而Cr^(3+)和Cu^(2+)抑制FQs的吸附.准一级动力学模型和Freundlich模型拟合效果较好,说明吸附过程以化学吸附为主.两种实际水样中FQs的去除率均高达89.6%以上.实验表明,PG@CoFe_(2)O_(4)对含有氨基和卤素基团的污染物存在特异性吸附.

关键词：磷酸化磁性石墨烯微波辐射氟喹诺酮类抗生素吸附

壳聚糖/纳米纤维素/石墨烯改性纳米TiO_(2)复合膜光催化降解性能

在线全文

学校读者我要写书评

暂无评论

塑料工业 2022年第11期50卷 58-63,94页

作者：田清泉张禄媛王俊霞王怡渭南师范学院化学与材料学院陕西省煤基低碳醇转化工程研究中心陕西渭南714099

以氧化石墨烯改性纳米二氧化钛为光催化活性成分,通过流延成型法制备了壳聚糖/纳米纤维素/石墨烯改性纳米TiO_(2)光催化复合膜。利用热重分析仪(TG)、傅里叶红外光谱仪(FTIR)和扫描电子显微镜(SEM)对复合膜的结构进行表征。研究了壳聚糖... 详细信息

以氧化石墨烯改性纳米二氧化钛为光催化活性成分,通过流延成型法制备了壳聚糖/纳米纤维素/石墨烯改性纳米TiO_(2)光催化复合膜。利用热重分析仪(TG)、傅里叶红外光谱仪(FTIR)和扫描电子显微镜(SEM)对复合膜的结构进行表征。研究了壳聚糖/纳米纤维素/改性纳米TiO_(2)复合膜的力学性能,对比了复合膜对亚甲基蓝及甲基橙的光催化降解性能。结果表明,改性纳米TiO_(2)的添加提高了壳聚糖复合膜的力学性能及耐热性能。改性纳米TiO_(2)质量分数为4%的复合膜抗拉强度最大,达到43 MPa。改性纳米TiO_(2)质量分数为2%的复合膜断裂伸长率最大为13.6%。在模拟溶液质量浓度为20 mg/L时,改性纳米TiO_(2)质量分数为2%的复合膜对亚甲基蓝降解率最大,为51.7%。改性纳米TiO_(2)质量分数为4%的复合膜对甲基橙降解率最大,为42.2%。模拟溶液初始浓度愈高,则复合膜对亚甲基蓝及甲基橙降解率均降低。

关键词：壳聚糖纳米二氧化钛石墨烯纳米纤维素光催化降解