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Effect of amendments on the leaching behavior of alkaline anions and metal ions in bauxite residue
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作者 Tao Tian Jinaju Zhou +4 位作者 Feng Zhu Yuzhen Ye Ying Guo William Hartley Shengguo Xue 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第11期74-81,共8页
A column leaching experiment was used to investigate the efficacy of amendments on their ability to remove alkaline anions and metal ions from bauxite residue leachates.Treatments included,simulated acid rain (AR),pho... A column leaching experiment was used to investigate the efficacy of amendments on their ability to remove alkaline anions and metal ions from bauxite residue leachates.Treatments included,simulated acid rain (AR),phosphogypsum + vermicompost (PVC),phosphogypsum + vermicompost + simulated acid rain (PVA),and biosolids + microorganisms (BSM) together with controls (CK).Results indicated that amendment could effectively reduce the leachate pH and EC values,neutralize OH-,CO32-,HCO3-,and water soluble alkali,and suppress arsenic (As) content.Correlation analysis revealed significant linear correlations with pH and concentrations of OH-,CO32-,HCO3-,water-soluble alkali,and metal ions.BSM treatment showed optimum results with neutralizing anions (OH-,CO32-,and HCO3-),water soluble alkali,and removal of metal ions (Al,As,B,Mo,V,and Na),which was attributed to neutralization from the generation of small molecular organic acids and organic matter during microbial metabolism.BSM treatment reduced alkaline anions and metal ions based on neutralization reactions in bauxite residue leachate,which reduced the potential pollution effects from leachates on the soil surrounding bauxite residue disposal areas. 展开更多
关键词 BAUXITE RESIDUE LEACHATE Amendments ALKALINE ANIONS Metal ions
Pyrazole-Triazine Conjugate as Highly Selective and Sensitive Fluorescence Probe for Silver (Ⅰ) Detection and Its Imaging in Living Cells
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作者 LIU Yanhong YU Bingqiong +1 位作者 ZHU Qingya YAN Kun 《武汉大学学报:自然科学英文版》 CAS CSCD 2019年第5期409-416,共8页
A new fluorescence probe 2,2’-(6-(4-(diethylamino) phenyl)-1,3,5-triazine-2,4-diyl)bis(1 H-pyrazole-1,3-diyl) diacetate(EATPA) based on 1, 3, 5-triazine was designed and synthesized. It exhibited distinct fluorescenc... A new fluorescence probe 2,2’-(6-(4-(diethylamino) phenyl)-1,3,5-triazine-2,4-diyl)bis(1 H-pyrazole-1,3-diyl) diacetate(EATPA) based on 1, 3, 5-triazine was designed and synthesized. It exhibited distinct fluorescence quenching in the presence of silver ions that can be used for highly sensitive and selective detection of Ag^+. Fluorescence titration and Job’s plot analysis revealed the formation of [Ag(EATPA)2]^+ entity with high binding constant(1.43×10^4 L/mol) and low detection limit(0.882 μmol/L). Furthermore, live-cell imaging experiments demonstrated that EATPA is potentially applicable for the tracking of Ag^+ in living cells. 展开更多
关键词 FLUORESCENCE probe SILVER ions FLUORESCENCE quenching DETECTION limit cell IMAGING
Efficient improvement of 2.7 μm luminescence of Er3+:oxyfluoride glass containing gallium by Yb3+ ions codoping
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作者 Yapei Peng Xinqiang Yuan +3 位作者 Long Zhang Peiguang Yan Wenfei Zhang Shuangchen Ruan 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第5期487-491,共5页
Mid-infrared laser materials with low phonon energy have significant applications. However, the development of available glass systems for high-power laser gain medium have posed a great challenge.Therefore, we invest... Mid-infrared laser materials with low phonon energy have significant applications. However, the development of available glass systems for high-power laser gain medium have posed a great challenge.Therefore, we investigated the 2.7 μm spectroscopic properties of Er3+/Yb3+ -codoped oxyfluoride glass containing gallium, which were prepared by typically melting and quenching methods. The 2.7 μm luminescence properties of the Er3+/Yb3+-codoped oxyfluoride glass containing gallium were recorded by a 980 nm laser diode. The Judde Ofelt parameters, decay curves, emission cross section, energy transfer efficiency and quantum efficiency were calculated. The maximum emission cross section of YbFGa-0.5 is 1.63 × 10-20 cm2 by 980 nm excitation. The energy transfer efficiency is calculated to be77.8% for the YbFGa-0.5 glass around 2700 nm. The quantum efficiency at 1530 nm is 65.6%. The result reveals that the best doping concentration ratio of Er3+:Yb3+ ions is 1:0.5, and suggests an effective energy transfer from Yb3+ to Er3+ ions. 展开更多
关键词 OPTICAL materials OPTICAL spectroscopy RARE-EARTH IONS doped MID-INFRARED Energy transfer
Magnetism tuned by intercalation of various metal ions in coordination polymer
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作者 Chengfei Wang Wei Zhang +3 位作者 Wenwu Li Yuanyuan Zhang Xiaodong Tang Ming Hu 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第7期1390-1392,共3页
Incorporation of guest ions into porous frameworks changed magnetism of the host materials significantly. However, in most cases, the guest ions were monovalent due to lack of reliable method to insert divalent and tr... Incorporation of guest ions into porous frameworks changed magnetism of the host materials significantly. However, in most cases, the guest ions were monovalent due to lack of reliable method to insert divalent and trivalent guest ions. In this work, we demonstrated that divalent and trivalent metal ions could be inserted into frameworks of a coordinate polymer, Cu3[Fe(CN)6]2, through electrochemical intercalation. The magnetism of the host frameworks was changed among paramagnetic, superparamagnetic, and ferromagnetic as demonstrated by physical property measurement system (PPMS). Furthermore, the magnetization of the frameworks under low temperatures correlated to the guest ions significantly. The ionic radius and net charge of the guest ions influenced the intercalation amount of the guest ions, therefore affected the valence change of Fe3+ ions in the host frameworks, finally leading to variation of the magnetism of the host materials. 展开更多
关键词 ELECTROCHEMISTRY MAGNETISM GUEST ions Prussian Blue ANALOGUES
Effect of Na and Cl ions on water evaporation on graphene oxide 预览
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作者 Xi Nan Yu-Wei Guo Rong-Zheng Wan 《核技术:英文版》 SCIE CAS CSCD 2019年第8期42-49,共8页
Using molecular dynamics simulations, we investigate the influence of Na and Cl ions on the evaporation of nanoscale water on graphene oxide surfaces. As the concentration of NaCl increases from 0 to 1.5 M, the evapor... Using molecular dynamics simulations, we investigate the influence of Na and Cl ions on the evaporation of nanoscale water on graphene oxide surfaces. As the concentration of NaCl increases from 0 to 1.5 M, the evaporation rate shows a higher decrease on patterned graphene oxide than that on homogeneous graphene oxide.The analysis shows an obvious decrease in the evaporation rate from unoxidized regions, which can be attributed to the increased amount of Na^+ ions near the contact lines.The proximity of Na^+ significantly extends the H-bond lifetime of the outermost water molecules, which reduces the number of water molecules diffusing from the oxidized to unoxidized regions. Moreover, the effect of the ions on water evaporation is less significant when the oxidation degree varies in a certain range. Our findings advance the understanding of the evaporation process in the presence of ions and highlight the potential application of graphene oxide in achieving controllable evaporation of liquids. 展开更多
关键词 EVAPORATION IONS GRAPHENE OXIDE MOLECULAR dynamics simulation
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Lanthanide-based downshifting layers tested in a solar car race 预览
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作者 Sandra F.H.Correia Ana R.N.Bastos +3 位作者 Lianshe Fu Luís D.Carlos Paulo S.André Rute A.S.Ferreira 《光电进展(英文)》 2019年第6期1-8,共8页
The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting... The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting,luminescent downshifting (LDS) layers are very promising to shape the incident sunlight and,thus,we report here the use of Tb^3+- and Eu^3+-doped organic-inorganic hybrid materials as LDS layers on Si PV cells.Electrical measurements on the PV cell,done before and after the deposition of the LDS layers,confirm the positive effect of the coatings on the cell’s performance in the UV spectral region.The maximum delivered power and the maximum absolute external quantum efficiency increased 14% and 27%,respectively.Moreover,a solar powered car race was organized in which the small vehicle containing the coated PV cells presented a relative increase of 9% in the velocity,when compared to that with the uncoated one. 展开更多
关键词 photovoltaics downshifting LAYERS solar car ORGANIC-INORGANIC HYBRIDS LANTHANIDE IONS
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Interaction of H2^+ molecular beam with thin layer graphene foils
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作者 李敏 曲国峰 +10 位作者 王亦舟 朱洲森 师勉恭 周茂蕾 刘东 徐子虚 宋明江 张俊 白帆 廖小东 韩纪锋 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第9期164-168,共5页
The interaction of MeV H2^+ molecular ions with thin layer graphene and graphite foils was studied by using a highresolution electrostatic analyzer.A large number of fragment protons were observed at zero degree(along... The interaction of MeV H2^+ molecular ions with thin layer graphene and graphite foils was studied by using a highresolution electrostatic analyzer.A large number of fragment protons were observed at zero degree(along the beam direction) when the H2^+ beam was passing through the monolayer graphene foil, which indicates that the electron of the H2^+ molecular ions can be stripped easily even by the monolayer graphene foil.More trailing than leading protons were found in the energy spectrum, which means significant wake effect was observed in the monolayer graphene foil.The ratio of the numbers of trailing protons over leading protons first increased with the thickness for the much thinner graphene foils, and then decreased with the thickness for the much thicker graphite foils, which indicates that the bending effect of the wake field on the trailing proton varied with the foil thickness. 展开更多
关键词 H2^+ molecular IONS GRAPHENE electron STRIPPING WAKE effect
Er3+/Yb3+/Li+/Zn2+:Gd2(MoO4)3 upconverting nanophosphors in optical thermometry
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作者 Anita Kumari Lakshmi Mukhopadhyay Vineet Kumar Rai 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第3期242-247,共6页
Er3+-Yb3+-Li+:Gd2(MoO4)3 and Er3+-Yb3+-Zn2+:Gd2(MoO4)3 nanophosphors, synthesized by chemical co-precipitation technique were characterized through XRD,FESEM,dynamic light scattering(DLS),diffuse reflectance, photolum... Er3+-Yb3+-Li+:Gd2(MoO4)3 and Er3+-Yb3+-Zn2+:Gd2(MoO4)3 nanophosphors, synthesized by chemical co-precipitation technique were characterized through XRD,FESEM,dynamic light scattering(DLS),diffuse reflectance, photoluminescence, photometric and decay time analysis. The enhancement of about~28, ~149 and ~351 times in the green upconversion emission band is observed for the optimized Er3+-Yb3+,Er3+-Yb3+-Li+ and Er3+-Yb3+-Zn2+:Gd2(MoO4)3 nanophosphors in comparison to the singly Er3+ doped nanophosphors. The electric dipole-dipole interaction is found to be responsible for the concentration quenching. The temperature dependent behaviour of the two green thermally coupled levels of the Er3+ ions based on the fluorescence intensity ratio technique was studied. The maximum sensor sensitivity ~38.7 × 10-3 K-1 at 473 K for optimized Er3+-Yb3+-Zn2+ codoped Gd2(MoO4)3 nanophosphors is reported with maximum population redistribution ability~88% among the 2H11/2 and 4S3/2 levels. 展开更多
关键词 UPCONVERSION PHOSPHORS Dynamic light scattering Non-lanthanide ions OPTICAL thermometry Rare earths
Optically tunable fluorescent carbon nanoparticles and their application in fluorometric sensing of copper ions
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作者 Minhuan Lan Shaojing Zhao +5 位作者 Shuilin Wu Xiaofang Wei Yanzhao Fu Juanjuan Wu Pengfei Wang Wenjun Zhang 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第10期2576-2583,共8页
A series of carb on nano particles(CNPs)with emissi on wavele ngth ranging from 483 to 525 nm were prepared by hydrothermal treatme nt of poly-3-thiopheneacetic acid(PTA)and NaOH.The emission wavelength and surface ox... A series of carb on nano particles(CNPs)with emissi on wavele ngth ranging from 483 to 525 nm were prepared by hydrothermal treatme nt of poly-3-thiopheneacetic acid(PTA)and NaOH.The emission wavelength and surface oxidation degree of CNPs were shown to be controllable by simply adjusti ng NaOH concentration.These CNPs prese nted obvious fluoresce nee spectral response toward copper ions(Cu^2+)through static quenching caused synergistically by electron transfer and inner filter effect.The O-and S-containing groups on the surface of CNPs were dem on strated to be resp on sible for their outsta nding sensing performa nee.Based on that,a CN Ps-based ratiometric fluoresce nt probe for Cu^2+with a high fluoresce nee quenching rate constant of 1.4×10^5 L/mol and a short resp onse time(10 s)was developed.Their practical applications in detecting Cu^2+in pond water and living cells were also dem on strated. 展开更多
关键词 carbon nano particles tun able fluorometric copper ions
Optical properties and radiative rates of Nd3+ doped zinc-sodium phosphate glasses
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作者 A.A.El-Maaref Shimaa Badr +2 位作者 Kh.S.Shaaban E.A.Abdel Wahab M.M.ElOkr 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第3期253-259,共7页
Preparation using melt quenching technique and optical characterizations of Nd3+ doped Zn-Na phosphate glasses are presented. The structure of the present glasses was studied using X-ray diffraction and FT-IR spectros... Preparation using melt quenching technique and optical characterizations of Nd3+ doped Zn-Na phosphate glasses are presented. The structure of the present glasses was studied using X-ray diffraction and FT-IR spectroscopy. UV-vis spectra of the present glasses were analyzed at different concentrations of Nd2 O3. The effect of neodymium concentration on the density and energy band gap was investigated. The density of the present glasses slightly increases with the increasing of Nd2 O3. A small variation of energy band gap with the increasing of neodymium content is observed as well, while Eg values decrease with the increase of Nd2 O3 content. The Eg values lie between 4.36 and 4.69 eV. Based on the measured optical spectra, Judd-Ofelt theory was used to determine the optical parameters such as line strengths, optical intensity parameters(Ωt), transition probabilities, and transition lifetimes. Hypersensitive transitions were identified in the absorption spectrum, the greatest line strengths are recorded at the transitions2 G7/2+ 4 G5/2, 4 S3/2 + 4 F7/2 and 4 D1/2 + 4 D3/2+ 4 D5/2 + 2 I11/2 with wavelengths of 580, 475 and 355 nm,respectively. Lifetimes of the important 4 F3/2 laser-level were determined;which show decreasing trend with the increasing of Nd2 O3 content and are found to be between 0.838 and 1.595 ms. The uncertainty of the present results was estimated. The RMS deviations were determined, which show lower values than those in the literature. 展开更多
关键词 Phosphate glass UV-VIS spectroscopy Judd-Ofelt RADIATIVE rates REAR earth ions
基于C=N双键异构化传感机制的荧光探针
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作者 李欠 《化学通报》 CAS CSCD 北大核心 2019年第6期496-503,共8页
多种传感机制已经被用于荧光探针分子的设计中,其中,基于C=N双键异构化传感机制的荧光探针的研究近年来引起了较大关注。本文归纳总结了过去10年基于C=N双键异构化传感机制的阳离子、阴离子和中性分子探针的发展情况。文章最后对其应用... 多种传感机制已经被用于荧光探针分子的设计中,其中,基于C=N双键异构化传感机制的荧光探针的研究近年来引起了较大关注。本文归纳总结了过去10年基于C=N双键异构化传感机制的阳离子、阴离子和中性分子探针的发展情况。文章最后对其应用前景及发展趋势进行了展望。 展开更多
关键词 荧光探针 C=N双键异构化 离子 中性分子
Evaluation of trans-ferulic acid degradation by dielectric barrier discharge plasma combined with ozone in wastewater with different water quality conditions
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作者 任景俞 姜楠 +3 位作者 商克峰 鲁娜 李杰 吴彦 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第2期68-77,共10页
In this study, dielectric barrier discharge plasma and ozone(O3) were combined to synergistically degrade trans-ferulic acid(FA), and the effect of water quality on FA degradation was studied. The results showed that ... In this study, dielectric barrier discharge plasma and ozone(O3) were combined to synergistically degrade trans-ferulic acid(FA), and the effect of water quality on FA degradation was studied. The results showed that 96.9% of FA was degraded after 40 min treatment by the plasma/O3 process. FA degradation efficiency increased with the p H values. The presence of suspended solid and humic acid inhibited FA degradation. FA degradation efficiency increased as the water temperature increased to 30 °C. However, the further increase in water temperature was adverse for FA degradation. Effects of common inorganic ions on FA degradation were also investigated. The addition of Cl- inhibited the FA degradation, whileCO32- had both negative and positive influences on FA degradation.NO3- andSO42- did not have significant effect on FA degradation. Fe3+and Cu2+benefited FA degradation through the Fenton-like and catalytic ozonation reactions. 展开更多
关键词 dielectric BARRIER DISCHARGE OZONE trans-ferulic acid water quality INORGANIC ions
Selective removal of heavy metal ions in aqueous solutions by sulfide-selector intercalated layered double hydroxide adsorbent
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作者 Jing Wang Liang Zhang +5 位作者 Tianshu Zhang Ting Du Tao Li Tianli Yue Zhonghong Li Jianlong Wang 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第9期1809-1816,共8页
Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has bee... Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has been synthesized for selective heavy metal removal. The intercalation of sulfurated groups in the interlayer of the layered double hydroxide (LDH) nanosheets endows NFL-S as a selective heavy metal ion filter;the selectivity of NFL-S for heavy metals is in the order of Pb^2+> Cu^2+≥ Zn^2+> Cd^2+> Mn^2+, and NFL-S has high kd values for Pb2+(~10^6 mL/g) and Cu2+(~10^5 mL/g). Scanning electron microscopy. X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent. The selective adsorption behavior was systematically studied using batch experiments, and the performance was evaluated through kinetic and isotherm studies. Moreover, the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated, which shows great potential for water decontamination. 展开更多
关键词 Layered double hydroxide nanosheets SULFIDE SELECTIVE adsorption Heavy metal IONS
A lysosomal targeting fluorescent probe and its zinc imaging in SH-SY5Y human neuroblastoma cells
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作者 Houna Duan Yu Ding +3 位作者 Chusen Huang Weiping Zhu Rui Wang Yufang Xu 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第1期55-57,共3页
Zinc plays a significant role in oxidative balance and central nervous systems. Herein, we reported a highly sensitive fluorescent probe DR, bearing a morpholine group and a BPEN ligand in the naphthalimide fluorophor... Zinc plays a significant role in oxidative balance and central nervous systems. Herein, we reported a highly sensitive fluorescent probe DR, bearing a morpholine group and a BPEN ligand in the naphthalimide fluorophore. Upon Zn2+binding, DR exhibited remarkable fluorescence enhancement, and showed high sensitivity to Zn2+with the association constant of 4.9 ? 108 L/mol, and the detection limit of15 nmol/L. Confocal imaging experiments indicated that DR was able to localize to lysosomes in MCF-7 cells. Moreover, upon H2 O2 stimulation in SH-SY5 Y cells, endogenous release of Zn2+was observed. 展开更多
关键词 NAPHTHALIMIDE ZINC ions Cellular IMAGING LYSOSOME Fluorescent probe
Layer by Layer Assembly of Poly(Allylamine Hydrochloride)/Phosphate Ions and Poly(Sodium 4-Styrene Sulfonate) Membrane for Forward Osmosis Application 预览
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作者 ZHOU Wen YU Li +2 位作者 LI Yiming GAO Baoyu WANG Zhining 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期743-749,共7页
Based on the layer by layer(Lb L)assembly technology,the nano-scale composite membrane with excellent structure can be prepared by changing the polyelectrolyte and controlling the deposition conditions.Polyamines and ... Based on the layer by layer(Lb L)assembly technology,the nano-scale composite membrane with excellent structure can be prepared by changing the polyelectrolyte and controlling the deposition conditions.Polyamines and phosphate ions(Pi)can be self-organized to form supramolecular systems which could be exploited to stabilize the interfacial architecture.The LbL membrane was made of the positively charged poly(allylamine hydrochloride)(PAH)self-organized with Pi and the negatively charged poly(sodium 4-styrene sulfonate)(PSS)alternatively on top of a poly(acrylonitrile)(PAN)substrate.Compared to the membrane without Pi,the membrane assembled by PAH/Pi improved forward of flux and reduced flux of salt.The concentration of PAH and PSS,deposition time,pH and number of layers showed significant influences on the performance of the membrane.In this experiment,we systematically investigated the preparation conditions and under the optimized conditions the prepared membrane exhibited high water fluxes of 13.5 L m^-2 h^-1 with corresponding salt to water flux,Js/Jv,ratio of 0.07 g L^-1 tested by forward osmosis when DI water as feed solution and 2 mol L^-1 MgCl2 as draw solution. 展开更多
关键词 forward osmosis LAYER by layer(LbL) POLYELECTROLYTE phosphate ions
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Lead-free thermochromic perovskites with tunable transition temperatures for smart window applications
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作者 Jingwen Li Xiaolong Liu +5 位作者 Peixin Cui Junmeng Li Tao Ye Xi Wang Chuang Zhang Yong Sheng Zhao 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第9期1257-1262,共6页
The structural flexibility of hybrid perovskite materials allows for phase transition and consequently thermochromic properties.Here we investigate the thermochromic performance in a series of copper-based layered per... The structural flexibility of hybrid perovskite materials allows for phase transition and consequently thermochromic properties.Here we investigate the thermochromic performance in a series of copper-based layered perovskites with organic cations having different alky chain lengths. Their transition temperature is found to be dependent on the organic cations due to molecular motion and hydrogen bond interaction, providing possibilities to prepare thermochromic semiconductors near room temperature for smart window applications. 展开更多
关键词 LEAD-FREE perovskites THERMOCHROMIC transition ALKYL AMMONIUM ions LAYERED structures smart windows
Hofmeister离子对水溶液中热响应聚合物的局域环境的影响 预览
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作者 薛智敏 严传玉 +2 位作者 赵新辉 于东琨 牟天成 《物理化学学报》 SCIE CAS CSCD 北大核心 2019年第1期49-57,共9页
Hofmeister离子效应的机制仍然未知。为了进一步探索,我们应用质子核磁共振(1H-NMR)波谱研究了特定离子对聚(2-乙基-2-恶唑啉)和聚(N-异丙基丙烯酰胺)的模型化合物N,N-二甲基丙酰胺(NDA)和N-异丙基异丁酰胺(NPA)水溶液的局域环境的影响... Hofmeister离子效应的机制仍然未知。为了进一步探索,我们应用质子核磁共振(1H-NMR)波谱研究了特定离子对聚(2-乙基-2-恶唑啉)和聚(N-异丙基丙烯酰胺)的模型化合物N,N-二甲基丙酰胺(NDA)和N-异丙基异丁酰胺(NPA)水溶液的局域环境的影响。这些聚合物具有热响应性质,是重要的生物工程材料,也受到特异离子效应影响。通过将酰胺键两侧的两个甲基的化学位移的变化相关联,发现对于所有NDA的甲基,特异离子的作用几乎相同。然而,NPA是一个较大的分子,我们发现并不是所有的甲基具有相同程度的特异离子效应。这项研究的结果表明,霍夫梅斯特离子效应可能主要是一种全局效应,而离子与溶质的局部相互作用也起了关键作用。 展开更多
关键词 热响应聚合物 酰胺 霍夫梅斯特效应 离子 核磁共振波谱
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季节性冻融土壤盐分离子组成与冻结层盐分运移规律研究 预览
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作者 崔莉红 朱焱 +2 位作者 赵天兴 杨金忠 伍靖伟 《农业工程学报》 EI CAS CSCD 北大核心 2019年第10期75-82,共8页
该文对冻融过程中土壤盐分离子组成及冻结层盐分运移规律进行研究,在内蒙古河套灌区永联试验站开展了冻融期土壤水盐及其离子成分监测试验,分析了冻融期地温、冻结层深度、地下水埋深与水质、土壤含水率、土壤盐分及离子组成的变化规律... 该文对冻融过程中土壤盐分离子组成及冻结层盐分运移规律进行研究,在内蒙古河套灌区永联试验站开展了冻融期土壤水盐及其离子成分监测试验,分析了冻融期地温、冻结层深度、地下水埋深与水质、土壤含水率、土壤盐分及离子组成的变化规律,通过离子相关性分析确定了土壤盐分运移的主控离子成分和盐分类型,进一步利用二元水盐体系相图探讨了冻融期主控盐分的运移规律。结果表明:冻融期地温梯度变化主要发生在0~1.0 m范围土层中,地下水埋深在冻融期变化趋势为快速增大-缓慢增大-减少,地下水矿化度均值在融化期显著降低;研究区地下水中变异性最大的离子为Na^+、Cl^-和SO4^2–,土壤盐分运移和扩散是地下水矿化度变化的主要原因;土壤中Na^+、Cl^–与SO4^2–与含盐量相关系数高于0.9,冻融期土壤盐分浓度变化的主控盐分类型为氯化钠和硫酸钠;冻结层积盐或者脱盐取决于土壤盐分梯度和不同盐分的共饱和点,研究区最大氯化钠浓度(质量分数1.55%)和最大硫酸钠浓度(2.01%)均低于各自的共饱和点,当冻结前土壤溶液浓度梯度为正(从上到下浓度增大)时,冻结层易积盐,反之冻结层主要表现为脱盐。研究对阐明冻融期冻结层盐分累积规律的成因具有重要意义。 展开更多
关键词 冻融 离子 土壤 冻结层 水盐运移 水盐体系相图 河套灌区
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Removal of lead and cadmium ions by single and binary systems using phytogenic magnetic nanoparticles functionalized by 3-marcaptopropanic acid
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作者 Imran Ali Changsheng Peng Iffat Naz 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第4期949-964,共16页
The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting mate... The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting material(i.e. 3-MPA@PMNPs) characterized by FTIR, powder XRD, SEM, TEM, EDX, VSM, BET and TGA techniques and then further employed for the investigation of the adsorptive removal of lead(Pb^2+) and cadmium(Cd^2+) ions from aqueous solutions in single and binary systems. The material showed fastest adsorptive rate(98.23%) for Pb^2+ and(96.5%) Cd2+within the contact time of 60 min at pH 6.5 in the single system. The experimental data were fitted well to Langmuir isotherm, indicated monolayer adsorption of both metal ions onto 3-MPA@PMNPs and an estimated comparable adsorptive capacity of 68.41 mg·g^-1(Pb2+) and 79.8 mg·g^-1(Cd2+) at p H 6.5. However, kinetic data agreed well with pseudo-second-order model, and indicated that the removal mainly supported chemisorption and/or ion-exchange mechanism. Thermodynamic parameters such asΔGo,ΔHo, and ΔSo, were-3259.20, 119.35 and 20.73 for Pb^2+, and-1491.10, 45.441 and 7.87 for Cd^2+ at temperature 298.15 K, confirmed that adsorption was endothermic, spontaneous and favorable. The material demonstrated higher selectivity of Pb2+ and its removal efficiency was(98.20 ± 0.3)% in binary system experiments. The material persisted performance up-to seven(07) consecutive treatment cycles without losing their stability and offered comparable fastest magnetic separation(35 s) from aqueous solutions. Therefore, it is recommended that the prepared material can be employed to remove toxic heavy metal ions from water/wastewaters and this "green" method can easily be implemented at large scale in low economy countries. 展开更多
关键词 Green RECIPE Phytogenic magnetic NANOPARTICLES Physical characterization of NANOPARTICLES Lead and CADMIUM IONS REMOVAL
外源CaCl2缓解番茄裂果的生理机制 预览
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作者 崔守尧 吴震 +2 位作者 吕海萌 薛灵姿 蒋芳玲 《南京农业大学学报》 CAS CSCD 北大核心 2019年第1期59-65,共7页
[目的]本文旨在从生理水平探究外源CaCl2缓解番茄裂果的机制,为裂果的防控提供理论依据。[方法]以耐裂和易裂果番茄为材料,喷施10g·L^-1CaCl2溶液,统计番茄裂果率,测定抗氧化酶活性变化、相关离子(Ca2+、K+、Mg2+、B3+)含量、细胞... [目的]本文旨在从生理水平探究外源CaCl2缓解番茄裂果的机制,为裂果的防控提供理论依据。[方法]以耐裂和易裂果番茄为材料,喷施10g·L^-1CaCl2溶液,统计番茄裂果率,测定抗氧化酶活性变化、相关离子(Ca2+、K+、Mg2+、B3+)含量、细胞壁主要成分含量(纤维素和果胶)、细胞壁关键水解酶(纤维素酶和多聚半乳糖醛酸酶)活性。[结果]10g·L^-1CaCl2处理可以显著降低易裂果番茄的裂果率,降低果皮中过氧化氢(H2O2)和丙二醛(MDA)含量及抗氧化酶活性,使易裂番茄电导率显著下降。10g·L^-1CaCl2处理下,番茄果皮Ca2+、K+、B3+的含量显著升高,Mg2+含量下降;果皮中纤维素酶和多聚半乳糖醛酸酶活性降低,细胞壁中纤维素和果胶的含量增加。[结论]喷施CaCl2处理可以降低番茄果实的氧化胁迫伤害,稳定细胞膜结构,促进番茄对Ca2+、K+、B3+离子的吸收,减少对Mg2+的吸收,使Ca2+、B3+与细胞壁更易结合,从而增加细胞壁的强度,缓解裂果的发生。 展开更多
关键词 番茄 裂果 外源CaCl2 抗氧化系统 细胞壁 离子
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