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Interannual succession of phytoplankton community in a canyon-shaped drinking water reservoir during the initial impoundment period:Taxonomic versus functional groups 被引量:1
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作者 Yi Hou Ya Cheng +6 位作者 Kai Li Meng Yang Kangzhe Huang Gang Ji Ruikang Xue Tinglin Huang Gang Wen 《Journal of Environmental Sciences》 2025年第5期454-468,共15页
During the initial impoundment period of a canyon-shaped reservoir,the water body fluctuated violently regarding water level,hydrological condition,and thermal stratification.These variations may alter the structure o... During the initial impoundment period of a canyon-shaped reservoir,the water body fluctuated violently regarding water level,hydrological condition,and thermal stratification.These variations may alter the structure of phytoplankton community,resulting in algal blooms and seriously threatening the ecological security of the reservoir.It is of great significance to understand the continuous changes of phytoplankton in the initial impoundment period for the protection of reservoir water quality.Therefore,a two-year in-situ monitoring study was conducted on water quality and phytoplankton in a representative canyonshaped reservoir named Sanhekou and the interannual changes of phytoplankton community and its response to environmental changes during the initial impoundment period were discussed at taxonomic versus functional classification levels.The results showed that the total nitrogen and permanganate index levels were relatively high in the first year due to rapid water storage and heavy rainfall input,and the more stable hydrological conditions in the second year promoted the increase of algae density and the transformation of community,and the proportion of cyanobacteria increased significantly.The succession order of phytoplankton in the first year of the initial impoundment periodwas Chlorophyta-Bacillariophyta-Chlorophyta,or J/F/X1-P/MP/W1-A/X1/MP,respectively.And the succession order in the second year was Cyanobacteria/Chlorophyta-Bacillariophyta-Chlorophyta,or L_(M)/G/P-P/A/X1-X1/J/G.Water temperature,relativewater column stability,mixing depth,and pHwere crucial factors affecting phytoplankton community succession.This study revealed the interannual succession law and driving factors of phytoplankton in the initial impoundment period and provided an important reference for the operation management and ecological protection of canyon-shaped reservoirs. 展开更多
关键词 Canyon-shaped reservoir functional groups Initial impoundment Interannual succession Water quality
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Tuning surface functional groups and crystallinity in activated carbon for high-voltage lithium-ion capacitors
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作者 AN Ya-bin SUN Yu +5 位作者 ZHANG Ke-liang LI Chen SUN Xian-zhong WANG Kai ZHANG Xiong MA Yan-wei 《新型炭材料(中英文)》 北大核心 2025年第5期1085-1097,I0019-I0021,共16页
Lithium-ion capacitors(LICs)combine the high power dens-ity of electrical double-layer capacitors with the high energy density of lithium-ion batteries.However,they face practical limitations due to the narrow operati... Lithium-ion capacitors(LICs)combine the high power dens-ity of electrical double-layer capacitors with the high energy density of lithium-ion batteries.However,they face practical limitations due to the narrow operating voltage window of their activated carbon(AC)cathodes.We report a scalable thermal treatment strategy to develop high-voltage-tolerant AC cathodes.Through controlled thermal treatment of commer-cial activated carbon(Raw-AC)under a H_(2)/Ar atmosphere at 400-800℃,the targeted reduction of degradation-prone functional groups can be achieved while preserving the critical pore structure and increasing graph-itic microcrystalline ordering.The AC treated at 400℃(HAC-400)had a significant increase in specific capacity(96.0 vs.75.1 mAh/g at 0.05 A/g)and better rate capability(61.1 vs.36.1 mAh/g at 5 A/g)in half-cell LICs,along with an 83.5%capacity retention over 7400 cycles within an extended voltage range of 2.0-4.2 V in full-cell LICs.Scalability was demonstrated by a 120 g batch production,enabling fabrication of pouch-type LICs with commercial hard carbon anodes that delivered a higher energy density of 28.3 Wh/kg at 1 C,and a peak power density of 12.1 kW/kg compared to devices using raw AC.This simple,industry-compatible approach may be used for producing ad-vanced cathode materials for practical high-performance LICs. 展开更多
关键词 Activated carbon Lithium-ion capacitors Surface functional groups Microcrystalline domains High-voltage cathod
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Application of Functional Group Migration Strategies in Photodriven Difunctionalization of Unsaturated Hydrocarbons
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作者 He Chonglong Zhou Youkang +1 位作者 Duan Xinhua Liu Le 《有机化学》 北大核心 2025年第5期1478-1508,共31页
Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups in... Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated. 展开更多
关键词 visible-light-driven unsaturated hydrocarbon functional group migration difunctionalization
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Synergistic Functional Group Interactions for Stable Interfacial Adhesion:Insights from Amyloid-inspired Polymers
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作者 Jin-Wei Bai Wei Liu +4 位作者 Bin Wen Zhong-Li Lei Chen Li Hao Ren Peng Yang 《Chinese Journal of Polymer Science》 2025年第7期1096-1104,共9页
Amyloid-like proteins are critical for interfacial adhesion across various marine organisms and bacteria.However,the specific contributions of different functional residues remain unclear.Herein,we introduce an approa... Amyloid-like proteins are critical for interfacial adhesion across various marine organisms and bacteria.However,the specific contributions of different functional residues remain unclear.Herein,we introduce an approach to deconstruct and mimic these residues using synthetic homopolymers and random copolymers with phenyl,amino,carboxyl,and hydroxyl functional groups using reversible addition-fragmentation chain transfer(RAFT)polymerization.The resulting polymers,designed with comparable molecular weights(M_(n):10–20 kDa)and narrow dispersities(PDI<1.3),mimic the diverse surface chemistry of amyloid-like proteins,enabling systematic investigation of their adhesive properties.The interfacial adhesion forces of different polymer films were quantified using atomic force microscopy(AFM)with a colloidal probe.Remarkably copolymers with multiple functional groups demonstrated significantly enhanced adhesion compared to homopolymers,a trend corroborated by macroscopic shear strength and stability tests.These results highlight that the synergistic effects of multiple functional groups are crucial for achieving universal interfacial adhesion of macromolecules,offering insights into protein adhesion mechanisms,and guiding polymer-based interfacial modifications. 展开更多
关键词 Protein-mimetic polymers AMYLOID Adhesion mechanism Surface functional group Synergistic effect
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Charged functional groups modified porous spherical hollow carbon material as CDI electrode for salty water desalination
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作者 Yushan Ni Yunlong Pu +3 位作者 Jie Zhang Weiyan Cui Mingjun Gao Dongjiang You 《Journal of Environmental Sciences》 2025年第3期254-267,共14页
As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC... As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC)were synthesized as CDI electrode material for removing Na^(+)and Cl^(−)in salty water.Results showed that the average diameter of HC was approximately 180 nm,and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups,respectively.The sulfonic acid functionalized HC(HC-S)showed better electrochemical and desalting performance than the amino-functionalized HC(HC–N),with a maximum Faradic capacity of 287.4 F/g and an adsorptive capacity of 112.97 mg/g for NaCl.Additionally,92.63%capacity retention after 100 adsorption/desorption cycles demonstrates the excellent stability of HC-S.The main findings prove that HC-S is viable as an electrodematerial for desalination by high-performance CDI applications. 展开更多
关键词 Hollow carbon functional groups DESALINATION Capacitive deionization
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Response of organic matter pore development to functional groups in overmature marine shale:Insights from AFM-IR spectroscopy
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作者 ZHAO Jianhua LIU Keyu +8 位作者 ZHAO Shenghui HU Qinhong WU Wei CHEN Yang LIU Guoheng LI Junqian YU Lingjie YOU Zuhui WANG Ye 《Petroleum Exploration and Development》 2025年第2期445-458,共14页
Taking the Lower Silurian Longmaxi Formation shale in the Sichuan Basin as an example,this study employs atomic force microscopy-based infrared(AFM-IR)spectroscopy to analyze the submicron-scale molecular functional g... Taking the Lower Silurian Longmaxi Formation shale in the Sichuan Basin as an example,this study employs atomic force microscopy-based infrared(AFM-IR)spectroscopy to analyze the submicron-scale molecular functional groups of different types and occurrences of organic matter.Combined with the quantitative evaluation of pore development via scanning electron microscopy(SEM),the response of organic pore formation and evolution mechanisms to chemical composition and structural evolution of organic matter in overmature marine shale is investigated.The results indicate that the AFM-IR spectra of graptolite periderms and pyrobitumen in shale are dominated by the stretching vibrations of conjugated C=C bonds in aromatic compounds at approximately 1600 cm-1,with weak absorption peaks near 1375,1450 and 1720 cm-1,corresponding to aliphatic chains and carbonyl/carboxyl functional groups.Overall,the AFM-IR structural indices(A and C factors)of organic matter show a strong correlation with visible porosity in shales of equivalent maturity.Lower A and C factor values correlate with enhanced development of organic pores,which is associated with the detachment of more aliphatic chains and oxygen-containing functional groups during thermal evolution.Pyrobitumen-clay mineral composites generally exhibit superior pore development,likely attributable to clay mineral dehydration participating in hydrocarbon generation reactions that promote the removal of more functional groups.Additionally,hydrocarbon generation within organic-clay composites during high-over mature stages may induce volumetric expansion,resulting in microfracturing and hydrocarbon expulsion.The associated higher hydrocarbon expulsion rates promote the formation of larger pores and fracture-shaped pores along the flake-shaped clay minerals.This study highlights that the research of submicron-scale molecular functional groups provides a deeper understanding of organic matter evolution and pores development mechanisms in overmature shales,thereby offering critical theoretical parameters for reservoir evaluation in shale oil and gas exploration. 展开更多
关键词 AFM-IR spectroscopy organic matter molecular functional groups organic matter pore development Longmaxi Formation shale
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Algae functional group characteristics in reservoirs and lakes with different trophic levels in northwestern semi-humid and semi-arid regions in China 被引量:7
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作者 Jinsuo Lu Zhe Yang Ying Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第2期166-173,共8页
In order to study the differences in algae species and their biomass in water bodies in a region, three reservoirs and two lakes at the center of Guanzhong Plain were chosen to identify algae functional groups, measur... In order to study the differences in algae species and their biomass in water bodies in a region, three reservoirs and two lakes at the center of Guanzhong Plain were chosen to identify algae functional groups, measure biomass, and assess water quality, from January2013 to December 2014. The water bodies represented different trophic levels: one oligotrophic, three mesotrophic, and one eutrophic. Based on the Reynolds’ functional groups, they had 10 groups in common—B, P, D, X1, M, MP, F, S1, J, and G, but the algae biomasses and proportions were different. In the oligotrophic reservoir, functional group B reached a peak biomass of 576 × 104 L-1, which accounted for 31.27%. In the eutrophic lake,functional group D reached a peak biomass of 3227 × 104 L-1, which accounted for only13.38%. When samples collected from other water bodies with similar trophic levels were compared, we found differences in the algae species functional groups. The potential reasons for the differences in algae functional group characteristics in the different water bodies in the region were water temperature and nutritional states. 展开更多
关键词 functional group classifications Lakes and reservoirs Trophic levels functional group characteristics
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Research on Stoichiometry of Early-spring Herbs Functional Group in the Subtropical Artificial Wetland
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作者 牛晓音 常杰 +1 位作者 葛滢 郑家文 《Agricultural Science & Technology》 CAS 2011年第8期1182-1185,1190,共5页
[Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammoni... [Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammonium nitrogen and phosphorus concentrations.Potassium persulfate absorptiometry was used for the measurement of total N content,while the flame photometer was used to detect the potassium and sodium concentration in plants.All the nutrient determination of plant samples were repeated for four times.[Result]The four nutrient concentrations in almost all samples were in the normal range of natural plant nutrition concentrations;in early-spring herbs functional groups,different species showed diversity on the nutrient concentrations;plant height had no significant effect on the nutrient concentrations in plants;the nutrient concentrations of non-grass group plants were higher than that of grass group plants;the nutrient concentrations of the annual herb were higher than that of perennial herbs.[Conclusion]The study had provided basis for the understanding of the effects of changes in nutritional conditions on species diversity,community structure and succession of the system. 展开更多
关键词 Early-spring herbs functional group BIODIVERSITY Element STOICHIOMETRY
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Effect of acidic surface functional groups on Cr(Ⅵ) removal by activated carbon from aqueous solution 被引量:9
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作者 ZHOU Hualei CHEN Yunfa 《Rare Metals》 SCIE EI CAS CSCD 2010年第3期333-338,共6页
The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and a... The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and after modification was analyzed based on the nitrogen adsorption isotherms.The morphology of those activated carbons was characterized using scanning electronic microscopy (SEM).The surface functional groups were determined by Fourier transform infrared spectroscopy (FTIR).The quantity of those groups was measured by the Boehm titration method.Cr(VI) removal by the activated carbons from aqueous solution was investigated at different pH values.The results show that compared with H2SO4,HNO3 destructs the original pore of the activated carbon more seriously and induces more acidic surface functional groups on the activated carbon.The pH value of the solution plays a key role in the Cr(VI) removal.The ability of reducing Cr(VI) to Cr(III) by the activated carbons is relative to the acidic surface functional groups.At higher pH values,the Cr(VI) removal ratio is improved by increasing the acidic surface functional groups of the activated carbons.At lower pH values,however,the acidic surface functional groups almost have no effect on the Cr(VI) removal by the activated carbon from aqueous solution. 展开更多
关键词 activated carbon surface functional groups REMOVAL MODIFICATION chromium(VI)
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Biomass Allocation Patterns of Alpine Grassland Species and Functional Groups along a Precipitation Gradient on the Northern Tibetan Plateau 被引量:8
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作者 WU Jian-shuang SHEN Zhen-xi +1 位作者 ZHANG Xian-zhou SHI Pei-li 《Journal of Mountain Science》 SCIE CSCD 2013年第6期1097-1108,共12页
Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to ... Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to roots at the community level but allometrically at the species level in Tibetan alpine grasslands. These differences may result from the specific complementarity of functional groups between functional components, such as leaf, root, stem and reproductive organ. To test the component complementary responses to regional moisture variation, we conducted a multi-site transect survey to measure plant individual size and component biomass fractions of common species belonging to the functional groups: forbs, grasses, legumes and sedges on the Northern Tibetan Plateau in peak growing season in 2010. Along the mean annual precipitation (MAP) gradient, we sampled 7o species, in which 2o are in alpine meadows, 20 in alpine steppes, 15 in alpine desert-steppes and 15 in alpine deserts, respectively. Our results showed that the size of alpine plants is small with individual biomass mostly lower than 1.0 g. Plants keep relative conservative component individual responses moisture functional fractions across alpine grasslands at the level. However, the complementary between functional components to variations specifically differ among groups. These results indicate that functional group diversity may be an effective tool for scaling biomass allocation patterns from individual up to community level. Therefore, it is necessary andvaluable to perform intensive and systematic studies on identification and differentiation the influences of compositional changes in functional groups on ecosystem primary services and processes. 展开更多
关键词 Biomass fractions Complementaryresponse functional components functional groups Changtang Plateau
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The key environmental factors driving the succession of phytoplankton functional groups in Hongfeng Reservoir, southwest China 被引量:6
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作者 Libin HAN Qiuhua LI +4 位作者 Wensheng CHEN Xing WANG Shihui ZHOU Mengshu HAN Anton BRANCELJ 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第4期1472-1484,共13页
Reservoirs are an important water source in many densely populated areas in southwest China.Phytoplankton play an essential role in maintaining the structure and function of reservoir ecosystems.Understanding the succ... Reservoirs are an important water source in many densely populated areas in southwest China.Phytoplankton play an essential role in maintaining the structure and function of reservoir ecosystems.Understanding the succession in phytoplankton communities and the factors driving it are essential for eff ective water quality management in drinking water reservoirs.In this study,water samples were collected monthly at the surface layers from March 2016 to December 2019 in Hongfeng Reservoir,southwest China.The relationship between functional group succession was analyzed based on nonmetric multidimensional scaling analysis(NMDS),redundancy analysis(RDA),succession rate,and other analysis methods.The results showed distinct shifts in the community structure of phytoplankton functional groups within study period.The Cyclotella sp.was dominant in 2016 and 2017,and Pseudanabaena limnetica was the dominant group in 2018 and 2019.It appears that the phytoplankton composition and biomass are closely related to the water temperature and nutrient status in this reservoir.The results clearly showed that the permanganate index(COD_(Mn))was the key factor of dramatic phytoplankton functional group succession,and the change in succession rates was closely caused by total nitrogen concentration(TN).Therefore,the succession pattern and key factors of Hongfeng Reservoir revealed in this study were important guidance for the management of drinking water reservoirs in southwest China.A reasonable limit on exogenous nutrient input should be a priority,especially in high water temperature period. 展开更多
关键词 phytoplankton functional groups driving factors nonmetric multidimensional scaling succession rates Redundancy analysis
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Adsorption of cadmium ions from aqueous solutions by activated carbon with oxygen-containing functional groups 被引量:5
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作者 边宇 卞兆勇 +4 位作者 张俊宵 丁爱中 刘少蕾 郑蕾 王辉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第10期1705-1711,共7页
The adsorption of aqueous cadmium ions(Cd(Ⅱ)) have been investigated for modified activated carbon(AC-T)with oxygen-containing functional groups.The oxygen-containing groups of AC-T play an important role in Cd(Ⅱ) i... The adsorption of aqueous cadmium ions(Cd(Ⅱ)) have been investigated for modified activated carbon(AC-T)with oxygen-containing functional groups.The oxygen-containing groups of AC-T play an important role in Cd(Ⅱ) ion adsorption onto AC-T.The modified activated carbon is characterized by scanning electron microscopy,Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS).The results of batch experiments indicate that the maximal adsorption could be achieved over the broad pH range of 4.5 to 6.5.Adsorption isotherms and kinetic study suggest that the sorption of Cd(Ⅱ) onto AC-T produces monolayer coverage and that adsorption is controlled by chemical adsorption.And the adsorbent has a good reusability.According to the FT-IR and XPS analyses,electrostatic attraction and cation exchange between Cd(Ⅱ) and oxygen-containing functional groups on AC-T are dominant mechanisms for Cd(Ⅱ) adsorption. 展开更多
关键词 Activated carbon Oxygen-containing functional groups Cd(II) Adsorption mechanism
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The Trace Elements are Bounded by Organic Functional Groups in Coal:A Studying Result Based on FTIR Analysis 被引量:5
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作者 YANG Jianye WANG Guangheng ZHANG Weiguo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第1期154-165,共12页
The relationship between trace elements in coal and organic functional groups of coal, also some of aromatic structure, was investigated by using curve fitting of infrared spectra. Cluster analysis was also performed ... The relationship between trace elements in coal and organic functional groups of coal, also some of aromatic structure, was investigated by using curve fitting of infrared spectra. Cluster analysis was also performed according to the degree of affinity of organic groups to the trace elements. The results show that there is a possibility that trace elements, especially LREE, were bound to peripheral organic functional groups of middle rank coal macromolecule. The most possible functional group that binds trace element is the hydroxyl, and to the less degree, the asymmetric -CH3 and 〉CH2 stretching, -CH3 stretching, etc. The degree of affinity of trace elements to different functional groups varies. The tendency obeys the natural structural changing law of trace elements-- the periodic law. The deviation of some trace elements from this regular trend is attributed to the deviation of intrinsic "confusion degree" (conventional molar entropy) of the matter system of coal basin, which is affected by the inner and outer factors during the evolution. 展开更多
关键词 curve fitting organic functional groups in coal trace element periodic law of elements
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Functional groups to modify g-C3N4 for improved photocatalytic activity of hydrogen evolution from water splitting 被引量:4
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作者 Fan Yu Laichun Wang +6 位作者 Qiuju Xing Dengke Wang Xunheng Jiang Guangchao Li Anmin Zheng Fanrong Ai Jian-Ping Zou 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第6期1648-1653,共6页
Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride(g-C3 N4).Herein,g-C3 N4 with yellow(Y-GCN)and brown(C-GCN)were ... Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride(g-C3 N4).Herein,g-C3 N4 with yellow(Y-GCN)and brown(C-GCN)were prepared by using the fresh urea and the urea kept for five years,respectively,for the first time.Experimental results show that the H2 production rate of the C-GCN is 39.06μmol/h,which is about 5 times of the Y-GCN.Meantime,in terms of apparent quantum efficiency(AQ.E)at 420 nm,C-GCN has a value of 6.3%and nearly 7.3 times higher than that of Y-GCN(0.86%).The results of XRD,IR,DRS,and NMR show,different from Y-GCN,a new kind of functional group of—N=CH—was firstly in-situ introduced into the C-GCN,resulting in good visible light absorption,and then markedly improving the photocatalytic performance.DFT calculation also confirms the effect of the—N=CH—group band structure of g-C3N4.Furthermore,XPS results demonstrate that the existence of—N=CH—groups in C-GCN results in tight interaction between C-GCN and Pt nanoparticles,and then improves the charge separation and photocatalytic performance.The present work demonstrates a good example of"defect engineering"to modify the intrinsic molecular structure of g-C3N4 and provides a new avenue to enhance the photocatalytic activity of g-C3N4 via facile and environmental-friendly method. 展开更多
关键词 functional groups Graphitic carbon nitride Hydrogen evolution PHOTOCATALYSIS SYNTHESIS
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Influence of Functional Groups and Modification Sites of Metal-Organic Frameworks on CO2/CH4 Separation:A Monte Carlo Simulation Study
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作者 龚捷 李炜 李松 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第1期52-60,I0001,共10页
In order to explore the influence of modification sites of functional groups on landfill gas (CO2/CH4) separation performance of metal-organic frameworks (MOFs), six types of or- ganic linkers and three types of f... In order to explore the influence of modification sites of functional groups on landfill gas (CO2/CH4) separation performance of metal-organic frameworks (MOFs), six types of or- ganic linkers and three types of functional groups (i.e. -F, -NH2, -CH3) were used to construct 36 MOFs of pcu topology based on copper paddlewheel. Grand canonical Monte Carlo sim- ulations were performed in this work to evaluate the separation performance of MOFs at low (vacuum swing adsorption) and high (pressure swing adsorption) pressures, respectively. Simulation results demonstrated that CO2 working capacity of the unfunctionalized MOFs generally exhibits pore-size dependence at 1 bar, which increases with the decrease in pore sizes. It was also found that -NH2 funetionalized MOFs exhibit the highest CO2 uptake due to the enhanced Coulombic interactions between the polar -NH2 groups and the quadrupole moment of CO2 molecules, which is followed by -CH3 and -F functionalized ones. Moreover, positioning the functional groups -NH2 and -CH3 at sites far from the metal node (site b) exhibits more significant enhancement on CO2/CH4 separation performance compared to that adjacent to the metal node (site a). 展开更多
关键词 Metal-organic frmneworks Pore-size dependence functional groups Modifi-cation sites Interaction energy
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Nb_(2)CT_(x) MXene: High capacity and ultra-long cycle capability for lithium-ion battery by regulation of functional groups 被引量:4
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作者 Jiabao Zhao Jing Wen +6 位作者 Junpeng Xiao Xinzhi Ma Jiahui Gao Lina Bai Hong Gao Xitian Zhang Zhiguo Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第2期387-395,I0013,共10页
MXenes are well known for their potential application in supercapacitors due to their high-rate intercalation pseudocapacitance and long cyclability.However,the reported low capacity of pristine MXenes hinders their p... MXenes are well known for their potential application in supercapacitors due to their high-rate intercalation pseudocapacitance and long cyclability.However,the reported low capacity of pristine MXenes hinders their practical application in lithium-ion batteries.In this work,a robust strategy is developed to control the functional groups of Nb_2 CT_x MXene.The capacity of pristine Nb_2 CT_x MXene can be significantly increased by Li~+ intercalation and surface modification.The specific capacity of the treated Nb_2 CT_x is up to 448 mAh g^(-1) at 0.05 A g^(-1),and at a large current density of 2 A g^(-1) remains a high reversible capacity retention rate of 75% after an ultra-long cycle of 2000 cycles.These values exceed most of the reported pristine MXenes(including the most studied Ti_3 C_2 T_x) and carbon-based materials.It demonstrates that this strategy has great help to improve the electrochemical performance of pristine MXene,and the results enhance the promise of MXenes in the application of lithium-ion batteries. 展开更多
关键词 MXene Nb_(2)CT_(x) functional groups Lithium-ion batteries
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Tailoring biochar by PHP towards the oxygenated functional groups(OFGs)-rich surface to improve adsorption performance 被引量:3
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作者 Xinyue Xiong Zhanglin Liu +7 位作者 Li Zhao Mei Huang Lichun Dai Dong Tian Jianmei Zou Yongmei Zeng Jinguang Hu Fei Shen 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第6期3097-3100,共4页
In this work,a modification method of H_(3)PO_(4)plus H_(2)O_(2)(PHP)was introduced to targetedly form abundant oxygenated functional groups(OFGs)on biochar,and methylene blue(MB)was employed as a model pollutant for ... In this work,a modification method of H_(3)PO_(4)plus H_(2)O_(2)(PHP)was introduced to targetedly form abundant oxygenated functional groups(OFGs)on biochar,and methylene blue(MB)was employed as a model pollutant for adsorption to reflect the modification performance.Results indicated that parent biochars,especially derived from lower temperatures,substantially underwent oxidative modification by PHP,and OFGs were targetedly produced.Correspondingly,approximately 21.5-fold MB adsorption capacity was achieved by PHP-modified biochar comparing with its parent biochar.To evaluate the compatibility of PHP-modification,coefficient of variation(CV)based on MB adsorption capacity by the biochar from various precursors was calculated,in which the CV of PHP-modified biochars was 0.0038 comparing to0.64 of the corresponding parent biochars.These results suggested that the PHP method displayed the excellent feedstock compatibility on biochar modification.The maximum MB adsorption capacity was454.1 mg/g when the H_(3)PO_(4)and H_(2)O_(2)fraction in PHP were 65.2%and 7.0%;the modification was further intensified by promoting temperature and duration.Besides,average 94.5%H_(3)PO_(4)was recovered after 10-batch modification,implying 1.0 kg H_(3)PO_(4)(85%)in PHP can maximally modify 2.37 kg biochar.Overall,this work offered a novel method to tailor biochar towards OFGs-rich surface for efficient adsorption. 展开更多
关键词 BIOCHAR Oxidative modification Phosphoric acid Hydrogen peroxide Oxygenated functional groups
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Planktonic protist communities in semi-enclosed mariculture waters: temporal dynamics of functional groups and their responses to environmental conditions 被引量:2
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作者 XU Henglong WARREN Alan +2 位作者 AL-RASHEID Khaled A S ZHU Mingzhuang SONG Weibo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第4期106-115,共10页
The functional groups of planktonic protist communities and their responses to the changes of environmental conditions were investigated in a semi-enclosed shrimp-farming pond in Qingdao,Shandong Province,China,during... The functional groups of planktonic protist communities and their responses to the changes of environmental conditions were investigated in a semi-enclosed shrimp-farming pond in Qingdao,Shandong Province,China,during a six-month study period (a complete shrimp-culture cycle) from May to October 2002.The results reveal that: (1) the protist communities represented five trophic and functional groups of the species identified,about 60% were photoautotrophs,20% algivores,12% bacterivores,5% raptors and about 3% non-selectives;(2) the photoautotrophs,algivores and bacterivores were the primary contributors to the changes in the protist communities in short temporal scales,the succession of dominance typically being bacterivores→photoautotrophs→algivores,with the raptors dominating the protist communities in a single sample (early June);(3) the photoautotrophs and non-selectives were the primary contributors to the peak of protist abundance in early October whereas the photoautotrophs,bacterivores,raptors and non-selectives mainly gave rise to two bimodal peaks of biomass in July and October respectively;(4) five functional groups of protist communities represented significant correlations with water nutrients (i.e.,NH 3-N,NO 3-N,and PO 4 ),either alone or in combination with temperature,of which algivores and raptors were strongly correlated with phosphate and the concentration of Chl a,while bacterivores were strongly related to nitrogen and the concentration of bacteria.These findings confirm that planktonic protists are potentially useful bioindicators of water quality in the semi-enclosed mariculture system. 展开更多
关键词 environmental stress planktonic protists functional group microbial ecology marimculture
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Free radicals, apparent activation energy, and functional groups during low-temperature oxidation of Jurassic coal in Northern Shaanxi 被引量:3
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作者 Wang Caiping Xiao Yang +2 位作者 Li Qingwei Deng Jun Wang Kai 《International Journal of Mining Science and Technology》 EI CSCD 2018年第3期469-475,共7页
Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from... Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures. 展开更多
关键词 Free racial concentration functional groups Low-temperature oxidation Lande factor Apparent activation energy
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Synthesis and Adsorption Properties of Polystyrene-supported Chelating Resins Containing Heterocyclic Functional Groups 被引量:2
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作者 Chun Nuan JI Rong Jun QU +2 位作者 Chun Hua WANG Chang Mei SUN Qing Hua TANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第9期1193-1196,共4页
A series of new chelating resins with incorporating heterocyclic functional groups: pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of poly... A series of new chelating resins with incorporating heterocyclic functional groups: pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol containing sulfur. These chelating resins were found to show high adsorption capacities for Ag^+, Hg^2+, Au^3+ and Pd^2+, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins. 展开更多
关键词 Chelating resins heterocyclic functional groups spacer ann ADSORPTION metal ions
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