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Stress signaling caused by mitochondrial import malfunction can be terminated by SIFI:Importance of stress response silencing
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作者 Grace Hohman Michael Shahid Mohamed A.Eldeeb 《Neural Regeneration Research》 2026年第2期673-674,共2页
Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et a... Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive. 展开更多
关键词 activation stress pathways neurodegenerative disorders protein aggregatesmitochondrial import stress stress signaling protein aggregates goiran protein aggregates protein aggr neurodegenerative diseasesincluding
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Generation and clearance of myelin debris after spinal cord injury
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作者 Chaoyuan Li Wenqi Luo +6 位作者 Irshad Hussain Renrui Niu Xiaodong He Chunyu Xiang Fengshuo Guo Wanguo Liu Rui Gu 《Neural Regeneration Research》 2026年第4期1512-1527,共16页
Traumatic spinal cord injury often leads to the disintegration of nerve cells and axons,resulting in a substantial accumulation of myelin debris that can persist for years.The abnormal buildup of myelin debris at site... Traumatic spinal cord injury often leads to the disintegration of nerve cells and axons,resulting in a substantial accumulation of myelin debris that can persist for years.The abnormal buildup of myelin debris at sites of injury greatly impedes nerve regeneration,making the clearance of debris within these microenvironments crucial for effective post-spinal cord injury repair.In this review,we comprehensively outline the mechanisms that promote the clearance of myelin debris and myelin metabolism and summarize their roles in spinal cord injury.First,we describe the composition and characteristics of myelin debris and explain its effects on the injury site.Next,we introduce the phagocytic cells involved in myelin debris clearance,including professional phagocytes(macrophages and microglia)and non-professional phagocytes(astrocytes and microvascular endothelial cells),as well as other cells that are also proposed to participate in phagocytosis.Finally,we focus on the pathways and associated targets that enhance myelin debris clearance by phagocytes and promote lipid metabolism following spinal cord injury.Our analysis indicates that myelin debris phagocytosis is not limited to monocyte-derived macrophages,but also involves microglia,astrocytes,and microvascular endothelial cells.By modulating the expression of genes related to phagocytosis and lipid metabolism,it is possible to modulate lipid metabolism disorders and influence inflammatory phenotypes,ultimately affecting the recovery of motor function following spinal cord injury.Additionally,therapies such as targeted mitochondrial transplantation in phagocytic cells,exosome therapy,and repeated trans-spinal magnetic stimulation can effectively enhance the removal of myelin debris,presenting promising potential for future applications. 展开更多
关键词 foam cells lipid droplets lipid metabolism MACROPHAGES MICROGLIA myelin debris myelin proteins myelin sheath nerve regeneration PHAGOCYTOSIS spinal cord injury
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Emerging Role of 2D Materials in Photovoltaics:Efficiency Enhancement and Future Perspectives
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作者 Ghulam Dastgeer Muhammad Wajid Zulfiqar +7 位作者 Sobia Nisar Rimsha Zulfiqar Muhammad Imran Swagata Panchanan Subhajit Dutta Kamran Akbar Alberto Vomiero Zhiming Wang 《Nano-Micro Letters》 2026年第1期843-895,共53页
The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials off... The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials. 展开更多
关键词 2D materials Photovoltaics Interface engineering Work function tuning Energy harvesting
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Chemistry under extreme conditions: Pressure evolution of chemical bonding and structure in dense solids 被引量:9
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作者 Choong-Shik Yoo 《Matter and Radiation at Extremes》 SCIE CAS 2020年第1期59-72,共14页
Recent advances in high-pressure technologies and large-scale experimental and computational facilities have enabled scientists,at an unprecedented rate,to discover and predict novel states and materials under the ext... Recent advances in high-pressure technologies and large-scale experimental and computational facilities have enabled scientists,at an unprecedented rate,to discover and predict novel states and materials under the extreme pressure-temperature conditions found in deep,giant-planet interiors.Based on a well-documented body of work in this field of high-pressure research,we elucidate the fundamental principles that govern the chemistry of dense solids under extreme conditions.These include:(i)the pressure-induced evolution of chemical bonding and structure of molecular solids to extended covalent solids,ionic solids and,ultimately,metallic solids,as pressure increases to the terapascal regime;(ii)novel properties and complex transition mechanisms,arising from the subtle balance between electron hybridization(bonding)and electrostatic interaction(packing)in densely packed solids;and(iii)new dense framework solids with high energy densities,and with tunable properties and stabilities under ambient conditions.Examples are taken primarily fromlow-Z molecular systems that have scientific implications for giant-planet models,condensed materials physics,and solid-state core-electron chemistry. 展开更多
关键词 SOLIDS BONDING EXTREME
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Traditional uses,phytochemistry and pharmacology of Clerodendron glandulosum Coleb - a review 被引量:4
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作者 Ravirajsinh N Jadeja Menaka C Thounaojam +2 位作者 Thouchom Brojendro Singh Ranjitsinh V Devkar AV Ramachandran 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2012年第1期1-6,共6页
Present review for the first time provides a complete botanical description and information on ethnomcdicinal uses of Clerodendron glandulosum.Coleb(CG:Fam.Verbenaceae).Recent studies conducted from our laborator) pro... Present review for the first time provides a complete botanical description and information on ethnomcdicinal uses of Clerodendron glandulosum.Coleb(CG:Fam.Verbenaceae).Recent studies conducted from our laborator) provide pharmacological evidence for its anti-hypertensive,antidiabetic and anti-obesity potentials.Further,its beneficial potential in preventing in vitro and in vivo non-alcoholic steatohepatitis and atherosclerosis and potent hcpatoprotective and free radical scavenging abilities along with its acute and sub- chronic toxicologiesl evaluations are also reported from our laboratory.In keeping with its traditional uses,CG extract was capable of ameliorating experimentally induced hypertension,diabetes and obesity.Its beneficial potential against NASH induced oxidative stress and atherosclerosis can be attributed to its potent free radical scavenging potential.Non—toxic nature of CG leaf extract further provides added merit to its reported pharmacological properties.The present review summarizes the pioneering scientific evidence for the pharmacological effects of CG against related metabolic disorders like hypertension,diabetes and obesity along with anti oxidant potential and beneficial elicits against non alcoholic steatohepatitis. 展开更多
关键词 Clerodendron glandulosum.Coleb Hypertension HYPERLIPIDEMIA INSULIN resistance OBESITY ATHEROSCLEROSIS
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A Quantum Chemistry Study of Inhibition Properties of Imidazole and Its Derivatives on Iron Surface Corrosion 被引量:4
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作者 YAN Xiao-ci XIA Wen-bing +4 位作者 LIU Jie OU YANG-li LUO Ming-dao YANG Feng MIN Xin-min 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2001年第3期305-310,共6页
The geometries of imidazole and its derivatives were respectively optimized by using ab initio method, and the molecular orbital energy levels and the charge densities were obtained for their optimum geometries. The f... The geometries of imidazole and its derivatives were respectively optimized by using ab initio method, and the molecular orbital energy levels and the charge densities were obtained for their optimum geometries. The frontier orbital energy levels, and the net charges of N (1) atom and the imidazole ring of those molecules were obtained with ab initio and SCC-DV-Xα methods. It was found that the inhibition properties of those compounds change with the highest occupied molecular orbital energy levels, and the net charges of N (1) atom. We took four iron atoms on the crystal plane (100) of α-iron as the surface which was used to study the adsorption towards the inhibitors. The adsorption models of the inhibitor to be adsorbed on the Fe-cluster surface were optimized with SCC-DV-Xα method. It turns out that the most favorable model is that the inhibitor molecule is adsorbed on the Fe-cluster surface in an inclined state. The calculation shows that the stabilization energies of the systems are well correlated with the inhibition efficiencies. 展开更多
关键词 IMIDAZOLE ab initio SCC-DV-Xα algorithm Fe-cluster surface Inhibition efficiency
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Solvothermal Syntheses, Crystal Structures, Thermal Stability and Quantum Chemistry of Dinuclear Trialkyltin Complexes Constructed by Camphoric Acid 被引量:3
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作者 庾江喜 邝代治 +3 位作者 冯泳兰 朱小明 蒋伍玖 张复兴 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第10期1521-1526,共6页
Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(... Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(2-methyl-2-phenyl)propyltin] oxide under solvothermal conditions, and these complexes were characterized by infrared spectra, elemental analyses, and H NMR spectra. The crystal of 1 belongs to the monoclinic system, space group P21/c with a = 1.83478(19), b = 1.52707(18), c = 1.9849(2) nm, β = 122.515(7)°, Z = 4, V = 4.6896(9) nm^3, Dc = 1.324 g/cm^3, μ(MoKα) = 1.103 mm^-1, F(000) = 1952, R = 0.0697 and wR = 0.2040. In addition, thermal stability and quantum chemical calculation of 1 were also studied. 展开更多
关键词 trialkyltin complex camphoric acid solvothermal synthesis structure quantum chemistry
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Recent progress on discovery and properties prediction of energy materials:Simple machine learning meets complex quantum chemistry 被引量:4
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作者 Yongqiang Kang Lejing Li Baohua Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第3期72-88,共17页
In nature,the properties of matter are ultimately governed by the electronic structures.Quantum chemistry(QC)at electronic level matches well with a few simple physical assumptions in solving simple problems.To date,m... In nature,the properties of matter are ultimately governed by the electronic structures.Quantum chemistry(QC)at electronic level matches well with a few simple physical assumptions in solving simple problems.To date,machine learning(ML)algorithm has been migrated to this field to simplify calculations and improve fidelity.This review introduces the basic information on universal electron structures of emerging energy materials and ML algorithms involved in the prediction of material properties.Then,the structure-property relationships based on ML algorithm and QC theory are reviewed.Especially,the summary of recently reported applications on classifying crystal structure,modeling electronic structure,optimizing experimental method,and predicting performance is provided.Last,an outlook on ML assisted QC calculation towards identifying emerging energy materials is also presented. 展开更多
关键词 Energy materials Quantum chemistry Machine learning Structure-property relationship
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Recent advances in the chemistry of nitrogen,phosphorus and potassium as fertilizers in soil:A review 被引量:9
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作者 Sharhabil Musa YAHAYA Aliyu Ahmad MAHMUD +1 位作者 Mustapha ABDULLAHI Abdurrashid HARUNA 《Pedosphere》 SCIE CAS CSCD 2023年第3期385-406,共22页
The advent of civilization has made humans dependent on plants for food and medicine,leading to the intensification of agricultural production.The intense cultivation of crops has resulted in the depletion of availabl... The advent of civilization has made humans dependent on plants for food and medicine,leading to the intensification of agricultural production.The intense cultivation of crops has resulted in the depletion of available nutrients from soil,thereby demanding the application of excess nutrients to soil to improve yield.Thus,mineral fertilizer discovery and application have,in many ways,contributed greatly to meeting global food demands.However,aside from the positive effects of mineral fertilizers,their excessive application to soil produces large amounts of pollutants that affect environmental sustainability.This necessitates the study of the major mineral fertilizer elements(nitrogen(N),phosphorus(P),and potassium(K)),the forms in which they are applied to soil,and their chemistry/reactions in soil.Here,we reviewed the forms of different N,P,and K mineral fertilizers to provide current knowledge on their constituents,the chemistry of N,P,and K in soil to understand the reactions they undertake in soil,the efficient methods of fertilizer application for environmental sustainability,the effects of mineral fertilizer loss to the environment,and improved fertilization technologies for environmental sustainability.Nanofertilizers are a promising technology for sustainable agricultural production and are discussed in detail in this review. 展开更多
关键词 BIOFERTILIZER environmental sustainability fertilizer application method fertilizer form mineral fertilizer nanofertilizer nutrient loss nutrient use efficiency
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Conductivity of K_(10)H_3[Dy(SiW_4Mo_7O_(39))_2] Treated by Chemistry-Heated Diffusion of Sm and Gd Permeation 被引量:2
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作者 李中华 韦永德 +1 位作者 周百斌 王进福 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第6期697-698,共2页
Chemistry-heated diffused permeation was used to treat POMs. ICP, IR, TG-DTA, XPS were used to characterize K_(10)H_3[Dy(SiW_4Mo_7O_(39))_2] and the sample. The result show that Sm and Gd can be permeated into the bod... Chemistry-heated diffused permeation was used to treat POMs. ICP, IR, TG-DTA, XPS were used to characterize K_(10)H_3[Dy(SiW_4Mo_7O_(39))_2] and the sample. The result show that Sm and Gd can be permeated into the body of this sample, chemical bonds forming between Sm and other components and the conductivity of K_(10)H_3[Dy(SiW_4Mo_7O_(39))_2] improves by 0 9356×10~4 times. 展开更多
关键词 inorganic chemistry POMS rare earths co-permeation CONDUCTIVITY rare earths
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Recent progress on MOF/MXene nanoarchitectures:A new era in coordination chemistry for energy storage and conversion 被引量:2
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作者 Sada Venkateswarlu Sowjanya Vallem +6 位作者 Muhammad Umer N.V.V.Jyothi Anam Giridhar Babu Saravanan Govindaraju Younghu Son Myung Jong Kim Minyoung Yoon 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期409-436,I0009,共29页
The development of urbanization and industrialization leads to rapid depletion of fossil fuels.Therefore,the production of fuel from renewable resources is highly desired.Electrotechnical energy conversion and storage... The development of urbanization and industrialization leads to rapid depletion of fossil fuels.Therefore,the production of fuel from renewable resources is highly desired.Electrotechnical energy conversion and storage is a benign technique with reliable output and is eco-friendly.Developing an exceptional electrochemical catalyst with tunable properties like a huge specific surface area,porous channels,and abundant active sites is critical points.Recently,Metal-organic frameworks(MOFs)and two-dimensional(2D)transition-metal carbides/nitrides(MXenes)have been extensively investigated in the field of electrochemical energy conversion and storage.However,advances in the research on MOFs are hampered by their limited structural stability and conventionally low electrical conductivity,whereas the practical electrochemical performance of MXenes is impeded by their low porosity,inadequate redox sites,and agglomeration.Consequently,researchers have been designing MOF/MXene nanoarchitectures to overcome the limitations in electrochemical energy conversion and storage.This review explores the recent advances in MOF/MXene nanoarchitectures design strategies,tailoring their properties based on the morphologies(0D,1D,2D,and 3D),and broadening their future opportunities in electrochemical energy storage(batteries,supercapacitors)and catalytic energy conversion(HER,OER,and ORR).The intercalation of MOF in between the MXene layers in the nanoarchitectures functions synergistically to address the issues associated with bare MXene and MOF in the electrochemical energy storage and conversion.This review gives a clear emphasis on the general aspects of MOF/MXene nanoarchitectures,and the future research perspectives,challenges of MOF/MXene design strategies and electrochemical applications are highlighted. 展开更多
关键词 Metal-organicframework MXene MoF/MXene nanoarchitecture BATTERY SUPERCAPACITOR Electrochemical catalysis
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Thermochemistry on Coordination Behavior of Neodymium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate 被引量:2
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作者 任宜霞 焦宝娟 +4 位作者 陈三平 高胜利 赵凤起 胡荣祖 史启祯 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第2期210-214,共5页
The complex of neodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2 atmosphere. The title complex was identified as Et_2NH_2... The complex of neodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2 atmosphere. The title complex was identified as Et_2NH_2[Nd(S_2CNEt_2)_4] by chemical and elemental analyses and the bonding characteristics of which was characterized by IR. The enthalpies of solution of neodymium chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change of liquid-phase reaction of formation for Et_2NH_2[Nd (S_2CNEt_2)_4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of liquid-phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle. 展开更多
关键词 physical chemistry neodymium chloride hydrate diethylammonium dithyldithiocarbamate (D-DDC) (microcalorimetric) method THERMOCHEMISTRY rare earths
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Toxicity evaluation of ZnO and TiO_2 nanomaterials in hydroponic red bean(Vigna angularis) plant:Physiology, biochemistry and kinetic transport 被引量:2
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作者 Shanaz Jahan Yatimah Binti Alias +1 位作者 Ahmad Farid Bin Abu Bakar Ismail Bin Yusoff 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第10期140-152,共13页
The toxicity and kinetic uptake potential of zinc oxide(Zn O) and titanium dioxide(TiO2)nanomaterials into the red bean(Vigna angularis) plant were investigated. The results obtained revealed that Zn O, due to i... The toxicity and kinetic uptake potential of zinc oxide(Zn O) and titanium dioxide(TiO2)nanomaterials into the red bean(Vigna angularis) plant were investigated. The results obtained revealed that Zn O, due to its high dissolution and strong binding capacity, readily accumulated in the root tissues and significantly inhibited the physiological activity of the plant. However, TiO2 had a positive effect on plant physiology, resulting in promoted growth. The results of biochemical experiments implied that Zn O, through the generation of oxidative stress, significantly reduced the chlorophyll content, carotenoids and activity of stress-controlling enzymes. On the contrary, no negative biochemical impact was observed in plants treated with TiO2. For the kinetic uptake and transport study, we designed two exposure systems in which Zn O and TiO2 were exposed to red bean seedlings individually or in a mixture approach. The results showed that in single metal oxide treatments, the uptake and transport increased with increasing exposure period from one week to three weeks.However, in the metal oxide co-exposure treatment, due to complexation and competition among the particles, the uptake and transport were remarkably decreased. This suggested that the kinetic transport pattern of the metal oxide mixtures varied compared to those of its individual constituents. 展开更多
关键词 Metal oxides Physiological impacts Biochemical impacts Uptake kinetics TRANSLOCATION Growth inhibition
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Coordination chemistry of surface-associated ligands for solid-liquid adsorption of rare-earth elements 被引量:2
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作者 Jessica L.Hovey Timothy M.Dittrich Matthew J.Allen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第1期1-18,共18页
General guidelines for the design of ligands for the enrichment of rare-earth elements by solid-liquid adsorption are described using coordination chemistry.Relevant properties of ligands include selectivity of metal ... General guidelines for the design of ligands for the enrichment of rare-earth elements by solid-liquid adsorption are described using coordination chemistry.Relevant properties of ligands include selectivity of metal ions based on adjustment of donor atom polarizability,denticity,and the pKarange of the binding sites.The selectivity of solid-phase materials for the enrichment of rare-earth ions by the ligand design guidelines is outlined,with special consideration of additional variable factors including steric hindrance,saturated binding sites,variability in speciation caused by the identity of counterions and ionic strength,and size-exclusivity in ligands stemming from differences in bite angle,preo rganization of ligands,or intraligand interactions.This review analyzes some principles of selectivity of rare-earth elements with ligands organized by donor type from examples collected from reports published between 2009 and 2021. 展开更多
关键词 Chelating ligand Coordination chemistry Solid-phase material Rare-earth element SEPARATION Solid-liquid extraction
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Geochemistry of Sediments from the Lopare Basin(Bosnia and Herzegovina):Implications for Paleoclimate,Paleosalinity,Paleoredox and Provenance 被引量:3
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作者 AleksandraŠAJNOVIĆ Nenad GRBA +4 位作者 Franz NEUBAUER Milica KAŠANIN-GRUBIN Ksenija STOJANOVIĆ Nenad PETKOVIĆ Branimir JOVANČIĆEVIĆ 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第5期1591-1618,共28页
A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(d... A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(depth of 193 m)and Pot 3(depth of 344 m),showed that element abundances like boron(B),lithium(Li),strontium(Sr),uranium(U),chromium(Cr),nickel(Ni),magnesium(Mg),sodium(Na)and calcium(Ca)are much higher than average than in the upper continental crust(UCC).Chemical composition indicates at least two sources:(i)Mesozoic ophiolites occurring in the north of the investigated area,and(ii)dacito-andesitic pyroclastics(Mesozoic to Cenozoic).Lopare Basin sedimentation was influenced by strong evaporation resulting in a partly hypersaline lake,which formed during a warm climatic period,probably during the Miocene Climatic Optimum.A brief episode of humid climate conditions resulted in the basin fillingup and deposition of felsic sediments enriched in thorium(Th).Organic geochemistry shows that the majority of studied sediments contains predominantly immature to marginally mature algal organic matter(OM).The biomarker patterns are generally in agreement with the geological history of the Lopare Basin and inorganic and mineralogical data.Conversely,the molecular distribution of n-alkanes as reliable climatic andδ-MTTC as paleosalinity indicators do not support this conclusion. 展开更多
关键词 GEOCHEMISTRY provenance analysis paleoenvironmental conditions salinity/hypersalinity biomarker Lopare Basin Bosnia and Herzegovina
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Synthesis,Crystal Structure and Quantum Chemistry of Dibutyltin 3,4-Dimethoxybenzotate Compound 被引量:2
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作者 张复兴 王剑秋 +4 位作者 邝代治 冯泳兰 许志锋 张志坚 张可 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第10期1529-1535,共7页
The dibutyltin 3,4-dimethoxybenzotate compound {[(3,4-(CH3O)2C6H3COO) Sn(Bu-n)2]2O}2 has been synthesized by the reaction of dibutyltin oxide with 3,4-dimethoxybenzoic acid. Its structure was determined by X-ray... The dibutyltin 3,4-dimethoxybenzotate compound {[(3,4-(CH3O)2C6H3COO) Sn(Bu-n)2]2O}2 has been synthesized by the reaction of dibutyltin oxide with 3,4-dimethoxybenzoic acid. Its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the triclinic system,space group P1 with a = 1.2003(2),b = 1.2821(3),c = 1.3666(3) nm,α = 80.50(3),β = 65.56(3),γ = 73.36(3)°,Z = 2,V = 1.8318(6) nm3,Dc = 1.530 Mg·m-3,μ(MoKa) = 1.413 mm-1,F(000) = 860,R = 0.0554 and wR = 0.1092. In the complex,each tin atom adopts a distorted tigonal bipyramidal structure,and the dimer structure is shaped by one Sn2O2 planar four-membered ring. The stabilities of the title complex,along with its orbital energies and composition characteristics of some frontier molecular orbitals have been investigated by means of quantum chemistry calculation methods. 展开更多
关键词 DIBUTYLTIN 3 4-dimethoxybenzoic acid SYNTHESIS crystal structure ab initio method
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Redox chemistry of N_(4-)Fe^(2+)in iron phthalocyanines for oxygen reduction reaction 被引量:2
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作者 Anuj Kumar Ying Zhang +2 位作者 Yin Jia Wen Liu Xiaoming Sun 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第8期1404-1412,共9页
A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,... A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,three different iron phthalocyanines(FePcs)adsorbed on carbon nanotubes((NH2)4FePc@CNTs,(t-Bu)4FePc@CNTs,and FePc@CNTs)were evaluated to demonstrate the effect of the electron donating power of the substituents on the Fe^(3+)/Fe^(2+)redox potential of FePc@CNTs and the role of these composites as ORR mediators in alkaline media.The Fe^(3+)/Fe^(2+)redox potential of the FePcs was found to shift towards the cathodic region upon substitution with electron-donating groups.This up-field shift in the eg-orbital leads to a lower overlap between the onset potential of the Fe^(3+)/Fe^(2+)redox couple and that of the ORR,and thus,the ORR activity decreased in the following order based on the substitution of FePc:-H>-t-Bu>-NH2. 展开更多
关键词 Iron phthalocyanines Substitution effect Oxygen reduction reaction Carbon nanotubes Activity descriptor
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In-Situ Microscopic FTIR Spectroelectrochemistry of Ascorbic Acid in Poly(ethylene glycol)/LiClO_4 Electrolyte Paste and in the Presence of Dispersed Cobalt Hexacyanoferrate Microcrystalline Powder 被引量:1
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作者 GUO Li-ping LIN Xiang-qin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1999年第1期12-18,共7页
In-situ microscopic FTIR spectroelectrochemical technique(MFTIRs) was applied to studying the electrochemical oxidation of ascorbic acid(AA) in poly(ethylene glycol)(PEG) paste at a 100 μm diameter Pt disk electrod... In-situ microscopic FTIR spectroelectrochemical technique(MFTIRs) was applied to studying the electrochemical oxidation of ascorbic acid(AA) in poly(ethylene glycol)(PEG) paste at a 100 μm diameter Pt disk electrode. Using this technique, the catalytic ability of cobalt hexacyanoferrate(CoHCF) microcrystalline toward AA oxidation was also studied. It was found that the dispersed CoHCF powder in the PEG paste can generate well shaped thin layer cyclic voltammetric waves with the peak height proportional to the scan rate, corresponding to the Fe centered redox reactions. This oxidation step catalyzed the AA oxidation. Also, this pasted CoHCF powder generated well resolved in situ MFTIRs spectra, by which a chemical interaction between CC bond of AA ring and CoHCF lattice was revealed. A corresponding surface docking mechanism for the catalytic reaction has been proposed. 展开更多
关键词 In SITU MFTIRs Ascorbic acid Cobalt HEXACYANOFERRATE Polymer ELECTROLYTE MICROCRYSTALLINE DOCKING mechanism
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Corrosive electrochemistry of jamesonite 被引量:2
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作者 邱冠周 余润兰 +1 位作者 胡岳华 覃文庆 《中国有色金属学会会刊:英文版》 CSCD 2004年第6期1169-1173,共5页
The corrosive electrochemistry of jamesonite (Pb4FeSb6S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled ... The corrosive electrochemistry of jamesonite (Pb4FeSb6S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled by the corrosive reactions, growth of the metal-deficient and sulfur-riched layer, passivation and breakdown of elemental sulfur film on the electrode surface. The corrosive potential(φcorr) moves negatively, its corrosive current increases, and hydroxyl action becomes stronger with the rising pH value. The charge transfer resistance increases and the capacitance decreases due to the gradual growth of the metal-deficient and sulfur-riched layer on the mineral surface from -378 to 122 mV (vs SHE). Element sulfur layer is formed at the potential of 122 mV. The charge transfer resistance increases and its capacitance rises slowly due to the gradual breakdown of sulfur film at voltage from 222 mV to 422 mV. S2O2-3 and SO2-4 ions occur when the electrode potential is over 422 mV. Under basic condition, the hydrophobic hydroxyl precipitate occurs on jamesonite surface, so that its collectorless floatability is poor. Under the condition of pH 6.86, it can be deduced that the potential range of collectorless floatability of jamesonite is from 22 to 422 mV due to the passive action of the hydrophilic sulfur on jamesonite surface, and its optimum range of floatable potential is between 122 and 322 mV. 展开更多
关键词 电化学腐蚀 脆硫锑铅矿 浮选 周期伏安法
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Spectroscopic characterization and photochemistry of the Criegee intermediate CF_(3)C(H)OO 被引量:1
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作者 Lina Wang Zhuang Wu +1 位作者 Bo Lu Xiaoqing Zeng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第4期160-169,共10页
Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental impor... Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental importance in understanding the underlying mechanism of their atmospheric reactions.In sharp contrast to the intensively studied parent molecule(CH_(2)OO)and the alkyl-substituted derivatives,the knowledge about the fluorinated analogue CF_(3)C(H)OO is scarce.By carefully heating the triplet carbene CF_(3)CH in an O2-doped Ar-matrix to 35 K,the elusive carbonyl oxide CF_(3)C(H)OO in syn-and anti-conformations has been generated and characterized with infrared(IR)and ultraviolet-visible(UV-vis)spectroscopy.The spectroscopic identification is supported by^(18)O-labeling experiments and quantum chemical calculations at the B3 LYP/6-311++G(3df,3pd)and MP2/6-311++G(2d,2p)levels.Upon the long-wavelength irradiation(λ>680 nm),both conformers of CF_(3)C(H)OO decompose to give trifluoroacetaldehyde CF_(3)C(H)O and simultaneously rearrange to the isomeric dioxirane,cyclic-CF_(3)CH(OO),which undergoes isomerization to the lowest-energy carboxylic acid CF_(3)C(O)OH upon UV-light excitation at 365 nm.The O_(2)-oxidation of CF_(3)CH via the intermediacy of CF_(3)C(H)OO and cyclic-CF_(3)CH(OO)might provide new insight into the mechanism for the degradation of hydro-chlorofluorocarbon CF_(3)CHCl_(2)(HCFC-123)in the atmosphere. 展开更多
关键词 Criegee intermediates CF_(3)COOH(TFA) CF_(3)CHCl_(2)(HCFC-123) PHOTOCHEMISTRY Matrix-isolation spectroscopy
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