期刊文献+
共找到3,046篇文章
< 1 2 153 >
每页显示 20 50 100
Adsorption properties of a novel 3D graphene/MgO composite for heavy metal ions 被引量:5
1
作者 ZHOU Ying LIANG Chun-yan +1 位作者 YU Jin-gang JIANG Xin-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期813-823,共11页
A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric anal... A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric analysis(TGA),scanning electron microscopy(SEM),transmission electron microscope(TEM),powder X-raydiffraction(XRD)and X-rayphotoelectron spectroscopy(XPS)were employed to characterize the prepared 3D graphene/MgO composite.The adsorption performance of some metal ions on 3D graphene/MgO was investigated.The results showed that the adsorption capacity was greater than 3D graphene and the maximum adsorption capacity at 25℃was found to be 358.96 mg/g,388.4 mg/g and 169.8 mg/g for Pb^2+,Cd^2+and Cu^2+,respectively.The adsorption kinetic conformed to the pseudo-second-order kinetic model and the adsorption isotherm was well described by Langmuir model.The thermodynamic constants revealed that the sorption process was endothermic and spontaneous in nature.Based on the results of the removal of heavy metal ions from metal smelting wastewater,it can be concluded that the prepared 3D graphene/MgO composite is an effective and potential adsorbent. 展开更多
关键词 ADSORPTion heavy metal ion 3D graphene MGO
在线阅读 下载PDF
Selective removal of heavy metal ions from aqueous solutions with surface functionalized silica nanoparticles by different functional groups 被引量:3
2
作者 孔祥峰 杨斌 +4 位作者 熊恒 周阳 薛生国 徐宝强 王世兴 《Journal of Central South University》 SCIE EI CAS 2014年第9期3575-3579,共5页
The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) tri... The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) triethoxysilane(MPTES) and(3-Amincpropyl) trithoxysilane(APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared(FI-IR) and X-ray photoelectron spectroscopy(XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2+, Cu2+, Hg2+, Cd2+ and Zn2+ions in aqueous solutions. The results show that the(3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles(SiO2-MPTES) play an important role in the selective adsorption of Cu2+ and Hg2+, the(3-Amincpropyl) trithoxysilane(APTES) functionalized silica nanoparticles(SiO2-APTES) exhibited maximum removal efficiency towards Pb2+ and Hg2+, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2+ at room temperature, respectively. 展开更多
关键词 industrial silica fume surface functionalization heavy metal ions selective removal
在线阅读 下载PDF
Chelation Assignments of Ga^Ⅲ,Ge^Ⅳand Si^ⅣMetal Ions WithPipemidic Acid Antibiotic Drug:Synthesis,Spectroscopic Characterizations and Biological Studies
3
作者 Abeer A El-Habeeb 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2020年第10期3303-3308,共6页
Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·... Pipemidic acid is one of an efficient quinolone antibacterial drug.Thecomplexitybetween pipemidic acid“Hpipc”withgallium(Ⅲ),germanium(Ⅳ)and silicon(Ⅳ)afforded three molecular formulas of[Ga(pipc)2(H 2O)(Cl)]·4H 2O,1,[Ge(pipc)2(Cl)2]·4H 2O,2 and[Si(pipc)2(Cl)2]·4H 2O,3 complexes.These three new complexes were characterized based on elemental analysis,conductance,FTIR,UV-Vis,^1HNMR and XRD spectroscopy.The pipc chelate exhibits O,O coordinated through the carbonyl(C O)and carboxylato(COO)of both oxygen atoms.Six coordinate geometry was proposed regarding complexes of 2 and 3,so the axial position was occupied by two coordinated chlorideatoms.In vitro,the antibacterial,antifungal,and anti-cancer assessments concerning the synthesized pipc complexes were scanned.These complexes have an excellent anti-microbial activity. 展开更多
关键词 Pipemidic metal ions CHELATion FTIR XRD Biological activity
在线阅读 下载PDF
Electrochemical sensor based on a Co(Ⅱ)-based metal-organic framework for the detection of Cd^(2+)and Pb^(2+)
4
作者 GUO Wei GUO Zhuoyi +3 位作者 LI Xiaoxin ZHANG Wei YAN Juanzhi GUO Tingting 《无机化学学报》 北大核心 2025年第9期1889-1902,共14页
A cobalt-based metal-organic framework[Co_(3)(L)_(2)(1,4-bib)_(4)]·4H_(2)O(Co-MOF)was prepared using 5-[(4-carboxyphenoxy)methyl]isophthalic acid(H_(3)L)and 1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib)as ligands.The... A cobalt-based metal-organic framework[Co_(3)(L)_(2)(1,4-bib)_(4)]·4H_(2)O(Co-MOF)was prepared using 5-[(4-carboxyphenoxy)methyl]isophthalic acid(H_(3)L)and 1,4-bis(1H-imidazol-1-yl)benzene(1,4-bib)as ligands.Then,an electrochemical sensor modified with Co-MOF on a glassy carbon electrode(Co-MOF@GCE)was constructed for detecting Cd^(2+)and Pb^(2+)in aqueous solutions.The sensor exhibited a linear range of 1.0-16.0µmol·L^(-1)with a detection limit(LOD)of 4.609 nmol·L^(-1)for Cd^(2+),and 0.5-10.0µmol·L^(-1)with an LOD of 1.307 nmol·L^(-1)for Pb^(2+).Simultaneous detection of both ions within 0.5-7.0µmol·L^(-1)achieved LOD values of 0.47 nmol·L^(-1)(Cd^(2+))and 0.008 nmol·L^(-1)(Pb^(2+)),respectively.Analysis of real water samples(tap water,mineral water,and river water)yielded recoveries of 95%-105%,validating practical applicability.Density functional theory(DFT)calculations reveal that synergistic interactions between cobalt centers and N/O atoms enhance adsorption and electron-transfer efficiency.CCDC:2160744. 展开更多
关键词 metal-organic frameworks electrochemical sensor heavy metal ions square wave anodic stripping voltammetry
在线阅读 下载PDF
Mechanism of different particle sizes of quartz activated by metallic ion in butyl xanthate solution 被引量:2
5
作者 覃文庆 武佳佳 焦芬 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期56-61,共6页
To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The ... To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries. 展开更多
关键词 particle size QUARTZ metallic ion ACTIVATion butyl xanthate
在线阅读 下载PDF
Adsorption models for heavy metal biosorption 被引量:1
6
作者 郑成 虞启明 尹平和 《化工学报》 EI CAS CSCD 北大核心 2007年第1期145-148,共4页
Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, w... Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, without considering the underlying mechanisms of biosorption.Commonly used models for correlating biosorption isotherm data are briefly reviewed and the use of the adsorption models in correlating the desorption processes is analysed.A set of biosorption/desorption experiments for a marine alga derived biosorbent are carried out to test the use of the adsorption models in the desorption process.Experimental data indicate that the amount of the heavy metal ions desorbed from the biomass could not be calculated with the adsorption models.This suggests that the empirical use of adsorption models in the correlation may not be valid when the reversibility of the biosorption equlibrium in the desorption process needs to be considered.Therefore,mechanism based biosorption models are needed for better correlation of equilibrium isotherm data. 展开更多
关键词 BIOSORPTion MODEL HEAVY metal ion
在线阅读 下载PDF
PREPARATION AND CLEAVAGE MECHANISM OF CHELATES OF METAL IONS WITH EDTA LINKED TO OLIGODEOXYRIBONUCLEOTIDES
7
作者 Li Xiaoru(Department of Chemistry, Central South University of Technology,Changsha 410083,China)Wen Zhibin(Department of Basic Medicine,Hunan Medical University,Changsha 410078,China) 《Journal of Central South University》 SCIE EI CAS 1998年第1期47-50,共4页
The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming t... The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming these three chelates is calculated.For ODN5′EDTA Fe(Ⅱ) pH value is 5.8 to 8.6,pH 4.6~8.1 for ODN5′EDTA Co(Ⅱ),and pH 3.4~5.7 for ODN5′EDTA Cu(Ⅱ).Under such pH value conditions neither can Mg(Ⅱ) ion,necessary for cleavage reaction,be competitive with Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ) to form EDTA chelate,nor can it be precipitated.The cleavage mechanism of ODN5′EDTA Fe(Ⅱ) for DNA duplex is discussed.Modified ODN binds with DNA duplex in the major groove via hydrogen bond to form triple helix.In the presense of oxygen and reducing agent dithiothreitol,hydroxyl radicals species are generated as intermediates by catalysis of metal ions,and then oxidize the ribo ring and cut the doublestranded DNA at the sites close to the EDTA· Fe(Ⅱ). 展开更多
关键词 Oligodeoxyribonucleotide metal ionS chelate cleavage
在线阅读 下载PDF
4种重金属离子对中华鳖(Trionyx sinensis)稚鳖的急性致毒效应 被引量:12
8
作者 王志铮 吕敢堂 +2 位作者 施建军 申屠琰 毛文举 《海洋与湖沼》 CAS CSCD 北大核心 2009年第6期745-752,共8页
以5日龄中华鳖稚鳖为实验动物,采用静水停食实验法,在水温(27.4±1.3)℃条件下,开展了Hg2+、Cr6+、Cu2+、Zn2+对中华鳖稚鳖的急性毒性和加和等毒性强度联合毒性试验。结果表明,4种重金属离子对中华鳖稚鳖均呈现以蓄积为主导的急性... 以5日龄中华鳖稚鳖为实验动物,采用静水停食实验法,在水温(27.4±1.3)℃条件下,开展了Hg2+、Cr6+、Cu2+、Zn2+对中华鳖稚鳖的急性毒性和加和等毒性强度联合毒性试验。结果表明,4种重金属离子对中华鳖稚鳖均呈现以蓄积为主导的急性毒发效应,Cr6+、Zn2+对中华鳖稚鳖的急性致毒高峰期明显滞后于Hg2+、Cu2+;4种重金属离子毒性大小依次为Hg2+、Cu2+、Cr6+、Zn2+,其对中华鳖稚鳖96h的半致死质量浓度分别为5.98、16.42、28.90和91.88mg/L;所构建的中华鳖稚鳖累积死亡概率与重金属质量浓度和实验时间之间的数学模型,以及半致死时间-质量浓度回归方程,可作为侦查和分析重金属离子排放时间和致中华鳖稚鳖大量死亡时间的重要计算工具;Hg2+、Cr6+、Cu2+、Zn2+离子两两组合在加和等毒性强度下对中华鳖稚鳖96h联合急性毒性所呈现的致毒特征与离子种类及其毒性强度匹配情形密切相关。 展开更多
关键词 重金属离子 急性毒性 联合毒性 中华鳖稚鳖
在线阅读 下载PDF
Synthesis,Spectroscopic Characterization,Thermogravimetric and Biological Activity Evaluation of Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ),Ta(Ⅴ)Complexes With Indole-3-Acetic Acid Plant Hormone Ligand
9
作者 Jehan YAl-Humaidi Foziah AAl-Saif +2 位作者 Dalal NB injawhar Hanan ABakhsh Moamen SRefat 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2021年第2期658-664,共7页
Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ)and Ta(Ⅴ)complexes of indole-3-acetic acid(IAAH)ligand were synthesized,characterized by elemental analysis and various spectroscopic techniques like,IR,1H-NMR,X-ray powder diffraction,UV-Vi... Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ)and Ta(Ⅴ)complexes of indole-3-acetic acid(IAAH)ligand were synthesized,characterized by elemental analysis and various spectroscopic techniques like,IR,1H-NMR,X-ray powder diffraction,UV-Visible,thermogravimetry analysis,magnetic measurements,molar conductance and surface morphology using SEM.All the synthesized complexes of IAAH ligand have 1∶2 stoichiometry of the types[Te(IAA)2(NH 3)2]·2Cl(Ⅰ),[Se(IAA)2(NH 3)2]·2Cl(Ⅱ),[V(IAA)2(NH 3)(Cl)](Ⅲ),[Nb(IAA)2(Cl)3](Ⅳ),and[Ta(IAA)2(Cl)3](Ⅴ).Spectral analysis indicates octahedral geometry for the Te(Ⅳ),Se(Ⅳ)and V(Ⅲ)complexes,whereas both Nb(Ⅴ)and Ta(Ⅴ)have a seven-coordination.The bonding sites are the oxygen atoms of carboxylate group for the deprotonated indole-3-acetic acid(IAA)ligand.The thermogravimetry analysis studies gave evidence for the presence of other coordinated molecules(Cl or NH 3)in the composition of IAA complexes,which were further supported by IR and micro analytical measurements.The higher molar conductance data of tellurium and selenium(Ⅳ)complexes reveal that these chelates are electrolytes,while low conductivity values for the vanadium(Ⅲ),niobium and tantalum(Ⅴ)chelates indicated a non-electrolytes.To test the antibacterial property of the five complexes in this study,four bacterial strains Klebsiella(G-),Escherichia coli(G-),Staphylococcus aureus(G+)and Staphylococcus epidermidis(G+)were used in the investigation.The effects of the five complexes in the cytotoxicity of Caco-2 and Mcf-7 human cancer cell lines were studied Neutral red uptake assay for the estimation of cell viability/cytotoxicity protocol. 展开更多
关键词 Indole-3-acetic acid CHELATion IR metal ions TEM Antimicrobial test
在线阅读 下载PDF
Synthesis and Spectroscopic Characterizations of New Mercury(Ⅱ), Cerium(Ⅲ), and Thorium(Ⅳ) Captopril Drug Complexes
10
作者 Samy M.El-Megharbel Moamen S.Refat 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2020年第11期3649-3652,共4页
In this article, three types of metal ions with different oxidation state as mercury(Ⅱ), cerium(Ⅲ) thorium(Ⅳ) have been reacted with captopril drug(CAP). The isolated solid complexes were explained using elemental ... In this article, three types of metal ions with different oxidation state as mercury(Ⅱ), cerium(Ⅲ) thorium(Ⅳ) have been reacted with captopril drug(CAP). The isolated solid complexes were explained using elemental analysis, conductance measurements, infrared and 1H-NMR spectroscopy as well as the thermo gravimetric(TG/DTG) analysis. The micro analytical and spectroscopic results for all CAP complexes were agreement with the speculated structures. The stoichiometry for divalent Hg^2+, trivalent Ce^3+ and tetravalent Th(4+) metal ions with CAP ligand was established with 1∶2(M(n+):CAP) molar ratio. The qualitative analysis showed that in case of the mercury(Ⅱ) complex, the chloride ions didn't involved in the complexity, suggesting formula [Hg(CAP)2] in neutral form. However, regarding both Ce(Ⅲ) and Th(Ⅳ) complexes as [Ce(CAP)2(NO3)]·3 H2O and [Th(CAP)2(NO3)2(H2O)]·3 H2O formulas, the nitrate group is existed inside the coordination sphere. The infrared analysis data proved that CAP drug act as a bidentate ligand with the metal ions of Ce(Ⅲ) and Th(Ⅳ) through oxygen carbonyl group C=O and oxygen of the deprotonated carboxylic COOH group, while for the Hg(Ⅱ) complex, the CAP acts as a bidentate ligand through oxygen of C=O group and sulfur atom of the deprotonated -SH group. Thorium(Ⅵ) complex has a nine-coordinate geometry, while Hg(Ⅱ) and Ce(Ⅲ) have a four and six-coordination behaviors respectively. The 1H-NMR data of the CAP compound has a singlet sharp signal at 1.90 ppm due to the proton of -SH group, this peak absent in the spectrum of the Hg(Ⅱ) CAP complex upon the deprotonated of thiol group. 展开更多
关键词 Captopril drug metal ions FTIR 1H-NMR
在线阅读 下载PDF
海绵多孔状CoFe_(2)O_(4)/Nafion复合修饰电极检测重金属离子 被引量:1
11
作者 徐玉婷 储旭 曹晏 《现代化工》 CAS CSCD 北大核心 2021年第6期232-236,共5页
采用溶胶-凝胶法制备的多孔海绵状CoFe_(2)O_(4)尖晶石晶体,滴铸在玻璃碳电极(glassy carbon electrode,GCE)上作为修饰电极,继续滴加Nafion形成CoFe_(2)O_(4)/Nafion/GCE电极。在优化的条件下,修饰电极在0.02~0.10μmol/L内对于Pb(Ⅱ)... 采用溶胶-凝胶法制备的多孔海绵状CoFe_(2)O_(4)尖晶石晶体,滴铸在玻璃碳电极(glassy carbon electrode,GCE)上作为修饰电极,继续滴加Nafion形成CoFe_(2)O_(4)/Nafion/GCE电极。在优化的条件下,修饰电极在0.02~0.10μmol/L内对于Pb(Ⅱ)的检测灵敏度为68.50μA/(μmol·L),检测下限(limit of detection,LOD)为7.3 nmol/L(通过3σ方法计算)。进一步的XPS表征说明了活性材料对于重金属的络合作用。评估了所制备电极的重复性、干扰性以及实际湖水检测,结果均表明其优异的性能以及潜在的实用性。因此,CoFe_(2)O_(4)尖晶石晶体是潜在的重金属检测新型传感材料。 展开更多
关键词 Pb(Ⅱ) 方波溶出伏安法 重金属离子 NAFion 多孔海绵CoFe_(2)O_(4)晶体
在线阅读 下载PDF
荧光碳点的制备及其在重金属离子检测中的应用研究进展 被引量:2
12
作者 郭永艳 杨萍 +1 位作者 党铭铭 田雁飞 《化工新型材料》 北大核心 2025年第1期73-78,共6页
碳点是一种新型荧光碳纳米材料,具有光致发光、荧光稳定、无光漂白和水溶性好等特点,被广泛应用于环境监测、分析检测及光电元器件等领域。介绍了荧光碳点的制备方法,如电化学合成法、激光烧蚀法、水热法、超声波法、微波法和模板法等,... 碳点是一种新型荧光碳纳米材料,具有光致发光、荧光稳定、无光漂白和水溶性好等特点,被广泛应用于环境监测、分析检测及光电元器件等领域。介绍了荧光碳点的制备方法,如电化学合成法、激光烧蚀法、水热法、超声波法、微波法和模板法等,分析了荧光碳点在检测重金属离子过程中出现荧光淬灭的主要原因,综述了荧光碳点在重金属离子检测中的应用,并对其未来发展方向进行了展望。 展开更多
关键词 荧光碳点 制备 重金属离子检测 应用
在线阅读 下载PDF
不同金属盐离子对乳清分离蛋白纤维聚合物形成的影响 被引量:1
13
作者 董世鹏 刘美艳 +3 位作者 邹霈怡 刘丹 陈鑫 李然红 《食品工业科技》 北大核心 2025年第11期124-131,共8页
本研究旨在探究不同金属离子(NaCl、KCl、CaCl_(2)、AlCl_(3)和FeCl_(3))对乳清分离蛋白(whey protein isolate,WPI)纤维聚合物聚合动力学、形态和结构的影响。结果表明,不同金属离子影响了WPI纤维聚合物的最终结构和特征。NaCl、KCl和C... 本研究旨在探究不同金属离子(NaCl、KCl、CaCl_(2)、AlCl_(3)和FeCl_(3))对乳清分离蛋白(whey protein isolate,WPI)纤维聚合物聚合动力学、形态和结构的影响。结果表明,不同金属离子影响了WPI纤维聚合物的最终结构和特征。NaCl、KCl和CaCl_(2)对WPI的聚集影响较小,增加了溶液pH和电导率,而AlCl_(3)和FeCl_(3)加速了WPI的聚集,降低了溶液pH,增加了溶液电导率;与原始WPI纤维聚合物硫黄素T(Th T)荧光强度(388.92)相比,NaCl、KCl和CaCl_(2)增加Th T荧光强度分别至465.39、433.37和486.83,增加了WPI纤维聚合物的生成量,AlCl_(3)和FeCl_(3)降低Th T荧光强度分别至228.81和90.24,降低了WPI纤维聚合物的生成量;不同金属离子均改变了WPI聚合动力学,降低了(df/dt)_(max)值,并改变了滞后时间;NaCl、KCl和CaCl_(2)对WPI纤维聚合物的形态影响较小,AlCl_(3)和FeCl_(3)使WPI纤维聚合物更团簇、粗而杂乱;傅里叶红外光谱结果表明,NaCl、KCl和CaCl_(2)促进β-折叠结构生成,而AlCl_(3)和FeCl_(3)抑制了β-折叠生成,不同金属离子的加入均改变了纤维中β-链间的特征距离。这些结果为利用WPI制备不同聚集形态的纤维聚合物提供了科学依据。 展开更多
关键词 乳清分离蛋白 聚合动力学 金属离子 纤维聚合物 电导率 硫黄素T
在线阅读 下载PDF
分级木质素基活性炭的制备及其吸附效果研究 被引量:2
14
作者 李栋 许诚 +4 位作者 陈前进 凃研 刘建华 杨意琳 王磊 《中国造纸》 北大核心 2025年第1期29-35,共7页
本研究采用4种有机溶剂对碱木质素进行分级,得到4种不同相对分子质量的木质素级分;以磷酸为活化剂,在高温条件下制备木质素基活性炭(LAC),探讨不同制备条件及外部环境因素对LAC吸附效果的影响。结果表明,在越高的磷酸含量和活化温度下,... 本研究采用4种有机溶剂对碱木质素进行分级,得到4种不同相对分子质量的木质素级分;以磷酸为活化剂,在高温条件下制备木质素基活性炭(LAC),探讨不同制备条件及外部环境因素对LAC吸附效果的影响。结果表明,在越高的磷酸含量和活化温度下,相对分子质量较大的木质素级分制备的LAC对Cu^(2+)的吸附效果越好。采用1,4-二氧六环分级的木质素级分在浸渍质量比2.5∶1、活化温度800℃下制备的LAC比表面积最大(806.74 m^(2)/g),吸附效果最好,Cu^(2+)去除率达98.3%。同时,LAC在不同环境温度和pH值下,对Cu^(2+)去除率均保持较高水平;经过4次吸附-解吸循环后,吸附效率达81%以上,解吸效率在73%以上,表明分级木质素制备的LAC具有良好的环境稳定性和可循环利用性。 展开更多
关键词 木质素 有机溶剂分级 活性炭 重金属离子
在线阅读 下载PDF
香菇多糖金属离子对其结构和体内抗氧化活性的影响 被引量:1
15
作者 王慧 王岸娜 +1 位作者 董赵微 朱俊友 《食品科学》 北大核心 2025年第7期119-124,共6页
本实验利用乙二胺四乙酸二钠螯合脱除香菇多糖中的内源性金属离子,研究脱除金属离子香菇多糖的理化性质、结构和抗氧化活性变化。分别用硫酸-苯酚法、考马斯亮蓝法和间羟基联苯法检测脱金属离子前后香菇多糖总糖、蛋白质和糖醛酸含量,... 本实验利用乙二胺四乙酸二钠螯合脱除香菇多糖中的内源性金属离子,研究脱除金属离子香菇多糖的理化性质、结构和抗氧化活性变化。分别用硫酸-苯酚法、考马斯亮蓝法和间羟基联苯法检测脱金属离子前后香菇多糖总糖、蛋白质和糖醛酸含量,并通过高效凝胶渗透色谱法、离子色谱法、扫描电镜和X射线衍射技术分析香菇多糖分子质量、单糖组成和高级结构。同时利用动物实验测定脱除金属离子前后香菇多糖的体内抗氧化活性。结果表明,脱除金属离子后香菇多糖的总糖含量和糖醛酸含量升高,相对分子质量范围和分布发生变化,单糖组成不变,但比例发生改变。脱除金属离子后,香菇多糖表面结构变得松散,螺旋结构发生改变。小鼠血清抗氧化实验结果表明,脱除金属离子后,香菇多糖的体内抗氧化活性降低。综上,金属离子脱除会破坏香菇多糖结构并使其体内抗氧化活性减弱。 展开更多
关键词 香菇多糖 金属离子 结构 体内抗氧化活性
在线阅读 下载PDF
基于金属离子改性的Cu-SSZ-13催化剂在NH_(3)-SCR脱硝中的应用
16
作者 张巍 梁垚城 +8 位作者 伍乔 付业昊 尹艳山 成珊 阮敏 刘涛 周昭仪 张凯凯 李丹聪 《化工进展》 北大核心 2025年第7期3879-3891,共13页
选择性催化还原(NH_(3)-SCR)技术是当前广泛应用的脱硝技术,其关键在于研发高效稳定的催化剂。CuSSZ-13分子筛脱硝催化剂因其优异的N2选择性和良好的催化活性备受研究人员关注。然而,Cu-SSZ-13分子筛催化剂存在的抗硫性和水热稳定性不... 选择性催化还原(NH_(3)-SCR)技术是当前广泛应用的脱硝技术,其关键在于研发高效稳定的催化剂。CuSSZ-13分子筛脱硝催化剂因其优异的N2选择性和良好的催化活性备受研究人员关注。然而,Cu-SSZ-13分子筛催化剂存在的抗硫性和水热稳定性不足等问题严重限制了其工业应用。为了克服硫氧化物和水热老化对Cu-SSZ-13催化剂脱硝活性的影响,可通过向催化剂中引入不同的自由态金属离子来进行改性。本文综述了近年来有关碱(土)金属离子、过渡金属离子和稀土金属离子改性Cu-SSZ-13催化剂在NH_(3)-SCR反应中的应用,并阐述了其抗硫机制和水热稳定性强化方法。展望了未来研究方向:综合利用不同金属离子的特点并结合离子之间的协同作用,制备具有优良抗硫性和水热稳定性的新型Cu-SSZ-13催化剂,明确金属离子在SSZ-13分子筛中的存在形式和相互作用机制,以及通过实验和计算相结合制备高效的金属离子改性Cu-SSZ-13催化剂以满足工业化应用。 展开更多
关键词 选择性催化还原 催化剂 分子筛 金属离子改性 抗硫性 水热稳定性
在线阅读 下载PDF
载铁催化水解离中间层及双极膜性能研究
17
作者 杨蕊 范云双 +1 位作者 吴秀翠 王杰 《膜科学与技术》 北大核心 2025年第1期58-69,共12页
研究了埃洛石纳米管(HNTs)和含铁化合物在双极膜(BPM)界面层中对水解离的影响.采用流延法将FeCl_(3)掺杂的改性埃洛石纳米管(FeCl_(3)-HNTs)作为中间层进行双极膜的制备,并与空白双极膜、HNTs-BPM及商业双极膜进行对比,探究不同双极膜... 研究了埃洛石纳米管(HNTs)和含铁化合物在双极膜(BPM)界面层中对水解离的影响.采用流延法将FeCl_(3)掺杂的改性埃洛石纳米管(FeCl_(3)-HNTs)作为中间层进行双极膜的制备,并与空白双极膜、HNTs-BPM及商业双极膜进行对比,探究不同双极膜的性能.通过FTIR、XPS、SEM和EDS等表征研究了中间层材料的化学组成和结构;通过I~V曲线、EIS、稳定性和产酸碱情况对双极膜进行性能测试.结果表明,与空白样品相比,在电流密度为50 mA/cm^(2)条件下,FeCl_(3)-HNTs-BPM的跨膜电压降低了46%,180 min后H^(+)和OH^(-)浓度分别达到0.215 mol/L和0.225 mol/L,电流效率为81.2%,能耗为3.36 kW·h/kg;在24 h的监测下双极膜的电压变化幅度较小(1.16 V到1.25 V),具有良好的电压稳定性,且未出现分层现象,表明FeCl_(3)-HNTs作为中间层制备的双极膜有良好的应用前景. 展开更多
关键词 双极膜 埃洛石纳米管 水解离 金属离子
在线阅读 下载PDF
多壁碳纳米管与金纳米粒子修饰纳米通道电化学传感器及其在粮食重金属检测中的应用
18
作者 胡维 周玉蓉 +4 位作者 蒋栋磊 王楠玮 张思迪 张娜 王立峰 《食品工业科技》 北大核心 2025年第15期324-333,共10页
本研究开发了一种基于多壁碳纳米管(MWCNTs)和金纳米粒子(AuNPs)修饰纳米通道(阳极氧化铝AAO膜)的电化学传感器,并结合丝网印刷电极(SPCE),用于粮食中痕量镉离子(Cd^(2+))和铅离子(Pb^(2+))的检测。通过扫描电子显微镜(SEM)、透射电镜(T... 本研究开发了一种基于多壁碳纳米管(MWCNTs)和金纳米粒子(AuNPs)修饰纳米通道(阳极氧化铝AAO膜)的电化学传感器,并结合丝网印刷电极(SPCE),用于粮食中痕量镉离子(Cd^(2+))和铅离子(Pb^(2+))的检测。通过扫描电子显微镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)对AuNPs-MWCNTs@AAO膜表面形貌和结构进行了表征,同时采用循环伏安法(CV)和电化学阻抗谱(EIS)评估电化学性能。优化后的检测条件为:AAO膜超声处理10 min、缓冲溶液pH5.5、溶出电压−1.2 V、溶出时间180 s。在0.1~10.00μg/L浓度范围内,Cd^(2+)和Pb^(2+)的氧化峰电流与浓度呈现良好的线性关系,决定系数R2分别为0.9903和0.9993,检出限分别为0.23μg/L和0.11μg/L。传感器对常见干扰金属离子具有较好的选择性,即使在其浓度为100倍时,Cd^(2+)和Pb^(2+)的电流响应变化仍不超过5%。在重复性、重现性和长期稳定性方面,传感器表现出良好的可靠性,氧化还原峰电流的相对标准偏差(RSD)分别为2.5%和2.3%。该传感器制备简便,性能可靠,能够为粮食中痕量重金属离子的检测提供有效的技术支持。 展开更多
关键词 电化学传感器 纳米通道 多壁碳纳米管(MWCNTs) 金纳米粒子(AuNPs) 重金属 离子检测 粮食分析
在线阅读 下载PDF
金属离子改性氨基硅橡胶膜的制备及其气体分离性能研究
19
作者 张莹 郭猛 +2 位作者 潘阳 任秀秀 钟璟 《现代化工》 北大核心 2025年第9期189-195,共7页
选取聚二甲基硅氧烷(PDMS)和聚{3-[(2-氨乙基)氨基]丙基}甲基(二甲基)硅氧烷(NH_(2)-PDMS)两种不同的硅橡胶材料分别与1,4-双(三乙氧基硅基)苯(BTESB)交联,制备铸膜液,采用刮涂法将铸膜液刮涂于聚丙烯腈(PAN)支撑体上制备成膜,并将其应... 选取聚二甲基硅氧烷(PDMS)和聚{3-[(2-氨乙基)氨基]丙基}甲基(二甲基)硅氧烷(NH_(2)-PDMS)两种不同的硅橡胶材料分别与1,4-双(三乙氧基硅基)苯(BTESB)交联,制备铸膜液,采用刮涂法将铸膜液刮涂于聚丙烯腈(PAN)支撑体上制备成膜,并将其应用于气体分离。探究硅橡胶材料种类和铸膜液质量分数对膜分离性能的影响;通过金属掺杂对NH_(2)-PDMS进行改性研究,探究不同金属元素对材料结构及膜性能的影响。结果表明,相同质量分数下,NH_(2)-PDMS膜表现出更大的CO_(2)渗透速率;随着铸膜液质量分数的降低,NH_(2)-PDMS膜的CO_(2)渗透速率逐渐升高;随着金属元素的加入,改性NH_(2)-PDMS膜的CO_(2)渗透速率均增大。当NH_(2)-PDMS铸膜液质量分数为1.0%、加入金属Co时,膜的分离性能最佳,此时CO_(2)的渗透速率达到3.71×10^(-6) mol/(m^(2)·s·Pa),CO_(2)/N_(2)选择性为11。 展开更多
关键词 金属离子改性 氨基 硅橡胶膜 气体分离性能
在线阅读 下载PDF
过渡金属离子活化地下水厂泥饼除氨效能及机理
20
作者 刘晓丹 殷芳青 +4 位作者 程亚 黄廷林 熊子康 文刚 丁正华 《环境工程技术学报》 北大核心 2025年第4期1272-1281,共10页
因地下水厂泥饼含锰氧化物能够回收作为催化氧化去除水中氨的潜力材料,而过渡金属元素能使锰氧化物提高催化活性,故本研究在此基础上探究了5种过渡金属离子(Mn^(2+)、Fe^(2+)、Cu^(2+)、Co^(2+)、Ni^(2+))对泥饼催化氧化除氨活性形成(活... 因地下水厂泥饼含锰氧化物能够回收作为催化氧化去除水中氨的潜力材料,而过渡金属元素能使锰氧化物提高催化活性,故本研究在此基础上探究了5种过渡金属离子(Mn^(2+)、Fe^(2+)、Cu^(2+)、Co^(2+)、Ni^(2+))对泥饼催化氧化除氨活性形成(活化)的影响,并将活化效果最佳的泥饼负载石英砂滤料,考察其实际运行效果。结果表明:同时投加2种不同的过渡金属离子及单独投加Cu^(2+)、Co^(2+)、Ni^(2+)时会抑制泥饼形成除氨活性,而单独投加Mn^(2+)或Fe^(2+)时会促进其形成良好除氨活性。其中每克泥饼投加0.5 mg Fe^(2+)能够使泥饼形成最好活性,在该条件下泥饼催化氧化除氨的能力提高近30%,氨去除速率可达0.234 mg/(g·h)。将该活化条件下泥饼负载滤料后,可使滤柱启动时间缩短近10 d,连续运行13 d后氨去除率稳定达到96.7%,且滤料在实际地下水和地表水环境下均适用。通过表征分析,泥饼经过Fe^(2+)活化后生成更多以Fe_(2)O_(3)和FeOOH形态为主的铁物相,其中FeOOH中的氧原子活性位点活跃,利于与反应体系中的氨反应;Mn(Ⅲ)、金属—O及金属—OH的含量上升,增强了泥饼催化氧化活性。活化后泥饼及其反应后溶液中均不含有致病微生物,重金属元素未超标,将其负载滤料应用后出水水质良好。该技术为高效利用废物资源及提高水厂除氨效率提供新思路,具备实际应用价值。 展开更多
关键词 地下水厂泥饼 过渡金属离子 催化氧化 锰氧化物
在线阅读 下载PDF
上一页 1 2 153 下一页 到第
使用帮助 返回顶部