期刊文献+
共找到4,904篇文章
< 1 2 246 >
每页显示 20 50 100
Enhancement of gaseous mercury(Hg^0) adsorption for the modified activated carbons by surface acid oxygen function groups
1
作者 GUO Si-jia GUO Gui-ping 《Journal of Groundwater Science and Engineering》 2018年第2期104-114,共11页
This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simu... This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simulated flue gas at 140 ℃. These surface acid oxygen function groups were identified by Boehm titration, Fourier transformation infrared spectrum, temperature programmed desorption and X-ray photoelectron spectroscopy. It indicates that the carboxyl, lactone and phenolic were formed when the benzoic acid is loaded on the surface of activated carbons. Among the surface acid oxygen function groups, the carboxyl groups enhance the adsorption capacities of Hg^0 for activated carbons to a greater extent. 展开更多
关键词 Benzoic acid Modified activated carbon Surface acid oxygen function groups Characterization Adsorption for Hg^0
在线阅读 下载PDF
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
2
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
原文传递
Application of Functional Group Migration Strategies in Photodriven Difunctionalization of Unsaturated Hydrocarbons
3
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
原文传递
Synergistic Functional Group Interactions for Stable Interfacial Adhesion:Insights from Amyloid-inspired Polymers
4
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
原文传递
Charged functional groups modified porous spherical hollow carbon material as CDI electrode for salty water desalination
5
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
原文传递
Response of organic matter pore development to functional groups in overmature marine shale:Insights from AFM-IR spectroscopy
6
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
在线阅读 下载PDF
Innovative Aczel Alsina Group Overlap Functions for AI-Based Criminal Justice Policy Selection under Intuitionistic Fuzzy Set
7
作者 Ikhtesham Ullah Muhammad Sajjad Ali Khan +3 位作者 Fawad Hussain Madad Khan Kamran Ioan-Lucian Popa 《Computer Modeling in Engineering & Sciences》 2025年第8期2123-2164,共42页
Multi-criteria decision-making(MCDM)is essential for handling complex decision problems under uncertainty,especially in fields such as criminal justice,healthcare,and environmental management.Traditional fuzzy MCDM te... Multi-criteria decision-making(MCDM)is essential for handling complex decision problems under uncertainty,especially in fields such as criminal justice,healthcare,and environmental management.Traditional fuzzy MCDM techniques have failed to deal with problems where uncertainty or vagueness is involved.To address this issue,we propose a novel framework that integrates group and overlap functions with Aczel-Alsina(AA)operational laws in the intuitionistic fuzzy set(IFS)environment.Overlap functions capture the degree to which two inputs share common features and are used to find how closely two values or criteria match in uncertain environments,while the Group functions are used to combine different expert opinions into a single collective result.This study introduces four new aggregation operators:Group Overlap function-based intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Averaging(GOF-IFAAWA)operator,intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Geometric(GOF-IFAAWG),intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)OrderedWeighted Averaging(GOF-IFAAOWA),and intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Ordered Weighted Geometric(GOF-IFAAOWG),which are rigorously defined and mathematically analyzed and offer improved flexibility in managing overlapping,uncertain,and hesitant information.The properties of these operators are discussed in detail.Further,the effectiveness,validity,activeness,and ability to capture the uncertain information,the developed operators are applied to the AI-based Criminal Justice Policy Selection problem.At last,the comparison analysis between prior and proposed studies has been displayed,and then followed by the conclusion of the result. 展开更多
关键词 Fuzzy sets(FS) intuitionistic fuzzy set(IFS) group function(GF) overlap function(OF) aczel alsina(AA)operators multi-criteria decision making problem(MCDM)
在线阅读 下载PDF
Combined Promoting Effects of Specific Organic Functional Groups and Alumina Surface Characteristics for the Design of a Highly Efficient NiMo/Al_(2)O_(3) Hydrodesulfurization Catalyst 被引量:2
8
作者 Li Huifeng Li Mingfeng +2 位作者 Zhang Le Wang Wei Nie Hong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期1-11,共11页
To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation betwe... To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases. 展开更多
关键词 ALUMINA Mo equilibrium adsorption capacity organic functional groups metal-support interaction HYDRODESULFURIZATION
在线阅读 下载PDF
Response of phytoplankton functional group to spring drought in a large subtropical reservoir 被引量:1
9
作者 Yue WU Qi YE +4 位作者 Siwen CHEN Kaining CHEN Shuzhan MA Yiheng CHANG Xiaoli SHI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第5期1586-1596,共11页
Global warming has caused an increase in the frequency and duration of droughts worldwide.Droughts could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a s... Global warming has caused an increase in the frequency and duration of droughts worldwide.Droughts could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a shift in the phytoplankton community.Spring diatom blooms in reservoirs have been increasingly observed in the past decade in the Taihu Lake basin.The aim of the present study is to elucidate the impacts of droughts on aquatic environment and to determine the driving factors for the succession of the phytoplankton functional groups based on the analysis of data collected during spring from 2009 to 2020 in the Daxi Reservoir.The unimodal relationship between 1-month aggregated precipitation index and phytoplankton species richness indicated the competitive exclusion occurred in extremely drought period.The structural equation modeling indicated that drought-related low water level conditions intensified sediment resuspension,and increased the phosphorus-enriched nonalgal turbidity in the Daxi Reservoir.Concurrently,a steady shift in the Reynolds phytoplankton functional groups from L 0,TD,J,X 2,and A(phytoplankton taxa preferring low turbidity and nutrient conditions)to TB(pennate diatoms being adapt to turbid and nutrient-rich conditions)was observed.The increased TP and non-algal turbidity in addition to the lowered disturbance contribute to the prevalence of Group TB.Considering the difficulties in nutrient control,timely water replenishment is often a feasible method of controlling the dominance of harmful algae for reservoir management.Finally,alternative water sources are in high demand for ensuring ecological safety and water availability when dealing with drought. 展开更多
关键词 DROUGHT RESERVOIR sediments resuspension phytoplankton functional group DIATOM
在线阅读 下载PDF
Overstory functional groups indicate the legacy of land use in a secondary tropical forest in southwestern China
10
作者 Yun Deng Wenfu Zhang +9 位作者 Min Cao Jinlong Dong Hui Chen Xiaobao Deng Jiajia Liu Xiaoyang Song Shangwen Xia Liqing Sha Shengdong Yuan Luxiang Lin 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期91-105,共15页
Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due ... Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory species.In this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present forests.In the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from 1965.Factors that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree analysis.The coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory layer.The abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always different.Although the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH increased.The findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was multidimensional.Functional group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession. 展开更多
关键词 Historical disturbance Legacy effects Secondary forests Overstory species functional groups
在线阅读 下载PDF
The key factors on the composition of phytoplankton functional groups in different watersheds in the Huanghe River basin
11
作者 Jing DONG Feihu WANG +4 位作者 Shuwen ZHANG Huatao YUAN Xiaofei GAO Jingxiao ZHANG Xuejun LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第6期1909-1927,共19页
To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were s... To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were selected.The contents of nephelometric turbidity(NTU),total nitrogen(TN),and total phosphorus(TP)were significantly higher in rivers than that in lakes or reservoirs,whereas the pH and CODMn(chemical oxygen demand or potassium permanganate index)were lower.Results show that,27 PFGs,namely,assemblages A,B,C,D,E,F,G,H,J,K,LM,Lo,M,MP,N,P,S1,S2,T,TC,W1,W2,X1,X2,X3,XPh,and Y,were identified.Additionally,ANOSIM correlation analysis demonstrated significant differences in PFG composition between the riverine and lake-reservoir sections in the Huanghe River basin.In the riverine watersheds,the group MP was dominant,while assemblages B and J were prevalent in lakes and reservoirs.The Mantel correlation tests and RDA analysis showed that environmental variables,such as NTU,water temperature(WT),conductivity(Cond),and TP,were key driving factors of shaping the dominant PFGs of the study area.Using the Venn diagram based on variation partitioning analysis,PFGs were mainly influenced by WT and TP in lake-reservoir sites,while in the river sites were affected mainly by geo-climatic variables.This study helps understanding the PFGs in river ecosystems,and unraveling the key driving factors in different watersheds,which shall be important for the protection and management of entire Huanghe River basin. 展开更多
关键词 Huanghe River phytoplankton functional group driving factor riverine watershed lake-reservoir region
在线阅读 下载PDF
Establishment and Exploration of Functional Party Groups in Science and Technology Institutes under the Academy System:A Case Study of Runze College of Ningxia University
12
作者 Yue ZHOU 《Meteorological and Environmental Research》 2024年第5期17-20,共4页
The education and management of college student Party members is the focus of student Party building work in colleges and universities.In the context of students second classroom being conducted in the academy,the man... The education and management of college student Party members is the focus of student Party building work in colleges and universities.In the context of students second classroom being conducted in the academy,the management of student Party members should enhance their Party spirit cultivation through improving their self-management and self-monitoring.After the comprehensive reform of Ningxia University,Runze College targeted the characteristics of agricultural majors and set up functional Party groups to enable student Party members to play a pioneering and exemplary role in the second classroom.Runze College relies on the academy system and breaks through the traditional one-way management mode led by Party branch teachers in the second classroom of college students.It leverages the role of functional Party groups in off campus science and technology academies,and integrates Party building work into daily teaching and research and solving agricultural production technology problems for local villagers,achieving the goal of promoting and integrating Party building and business work,and improving each other. 展开更多
关键词 Academy system Science and technology academy functional Party group Establishment and exploration
在线阅读 下载PDF
Spherical Functions on Fuzzy Lie Group
13
作者 Murphy E. Egwe Samuel S. Sangodele 《Advances in Pure Mathematics》 2024年第4期185-195,共11页
Let G be a locally compact Lie group and its Lie algebra. We consider a fuzzy analogue of G, denoted by called a fuzzy Lie group. Spherical functions on are constructed and a version of the existence result of the Hel... Let G be a locally compact Lie group and its Lie algebra. We consider a fuzzy analogue of G, denoted by called a fuzzy Lie group. Spherical functions on are constructed and a version of the existence result of the Helgason-spherical function on G is then established on . 展开更多
关键词 Fuzzy Spherical function Fuzzy Lie group Fuzzy Manifolds
在线阅读 下载PDF
TPE-embedded functional macrocycles:From structural design to photophysical property and application
14
作者 Jianmin Jiao Jiehao Yu +1 位作者 Xueqi Tian Xiao-Yu Hu 《Chinese Chemical Letters》 2025年第6期6-8,共3页
Macrocyclic hosts play a crucial role in supramolecular chemistry and the development of supramolecular functional materials.Their well-defined cavities and diverse host-vip interactions endow macrocycles with excel... Macrocyclic hosts play a crucial role in supramolecular chemistry and the development of supramolecular functional materials.Their well-defined cavities and diverse host-vip interactions endow macrocycles with excellent stimuli responsiveness,facilitating efficient assembly construction.However,the limited availability of functional groups in conventional macrocycles restricts their ability to meet the demand for fabricating materials with multiple functionalities.To address this limitation,several research groups have introduced tetraphenylethylene(TPE),a well-known building block renowned for its remarkable aggregation-induced emission(AIE)effect,into the macrocycle framework.Herein,this paper summarizes the combination strategies and synergistic approaches that achieve multi-functionality by integrating TPE and macrocyclic architectures.The emission characteristics of TPE-embedded macrocycles are elucidated,and it is anticipated that more AIE-type macrocycles with innovative backbones and broad applications will emerge. 展开更多
关键词 macrocyclic hosts TETRAPHENYLETHYLENE supramolecular functional materialstheir functional groups macrocycles assembly constructionhoweverthe supramolecular chemistry aggregation induced emission
原文传递
Stable carbon isotope composition and intrinsic water use efficiency of different functional plants on the western slope of Wuyi Mountains,China
15
作者 HUANG Kangxiang CHEN Huimin +7 位作者 REN Jiusheng XU Fangfang ZHOU Wei YUAN Bosen ZHANG Yuan WU Ting XIAO Shengsheng SHI Fuxi 《Journal of Mountain Science》 2025年第7期2512-2526,共15页
Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate c... Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate change.However,there is currently a lack of consensus regarding the leaf-scale iWUE variation characteristics among different functional types.In this study,we measured theδ^(13)Cleaf and iWUE values of different functional plants(i.e.,life forms,leaf types,and mycorrhizal types)from 120 species across distinct habitat types(i.e.,hillside,nearpeak,and peak)in a subtropical forest on the western slope of Wuyi Mountains,southern China.The results showed that theδ^(13)Cleaf values of plants on the western slope of Wuyi Mountains ranged from-34.63‰to-30.04‰,and iWUE ranged from 5.93μmol mol^(-1)to 57.34μmol mol^(-1).Theδ^(13)Cleaf and iWUE values differed significantly among plant life forms,following the order of herbs>vine plants>shrubs>trees.Theδ^(13)Cleaf and iWUE values of ectomycorrhizal(ECM)species were greater than those of arbuscular mycorrhizal(AM)species despite there being no significant difference between plants with different leaf types(Simple leaves(SL)vs.Compound leaves(CL)).From the hillside to the peak,both at the community level and at the species level,theδ^(13)C values of leaves and iWUE values of plants exhibited an upward trend.The regression analysis revealed that leaf-scale iWUE was significantly negatively correlated with soil water content and significantly positively correlated with leaf phosphorus content.The findings indicated that leaf carbon isotope fractionation and corresponding iWUE can be influenced by life form,mycorrhizal type,and soil water availability.These insights provide a deeper understanding of the coupling mechanisms of carbon,water,and nutrients among different functional plant types in subtropical forests,and offer insights into predicting plant adaptability under climate change. 展开更多
关键词 Stable carbon isotope Water use efficiency Plant functional groups Subtropical forest
原文传递
Research on Stoichiometry of Early-spring Herbs Functional Group in the Subtropical Artificial Wetland
16
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
在线阅读 下载PDF
Role of biochar surface characteristics in the adsorption of aromatic compounds:Pore structure and functional groups 被引量:15
17
作者 Xue-Fei Tan Shi-Shu Zhu +4 位作者 Ru-Peng Wang Yi-Di Chen Pau-Loke Show Feng-Fa Zhang Shih-Hsin Ho 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第10期2939-2946,共8页
Biochar(BC)are widely used as highly efficient adsorbents to alleviate aromatics-based contaminants due to their ease of preparation,wide availability,and high sustainability.The surface properties of BCs usually vary... Biochar(BC)are widely used as highly efficient adsorbents to alleviate aromatics-based contaminants due to their ease of preparation,wide availability,and high sustainability.The surface properties of BCs usually vary greatly due to their complex chemical constituents and different preparation processes and are reflected in the values of parameters such as the specific surface area(SSA),pore volume/size,and surface functional groups(SFGs).The effects of SSA and pore volume/size on the adsorption of aromatics have been widely reported.However,the corresponding mechanisms of BC SFGs towards aromatics adsorption remains unclear as the compositions of the SFGs are usually complex and hard to determine.To address in this gap in the literature,this review introduces a new perspective on the adsorption mechanisms of aromatics.Through collecting previously-reported results,the parameters log P(logarithm of the Kow),polar surface area,and the positive/negative charges were carefully calculated using Chem Draw3D,which allowed the hydrophobicity/hydrophilicity properties,electron donor-acceptor interactions,Hbonding,and electrostatic interactions between SFGs and aromatics-based contaminates to be inferred intuitively.These predictions were consistent with the reported results and showed that tailor-made BCs can be designed according to the molecular weights,chemical structures,and polarities of the target aromatics.Overall,this review provides new insight into predicting the physicochemical properties of BCs through revealing the relationship between SFGs and adsorbates,which may provide useful guidance for the preparing of highly-efficient,functional BCs for the adsorption of aromatics. 展开更多
关键词 BIOCHAR Surface characteristics AROMATICS ADSORPTION Surface functional groups
原文传递
Effect of acidic surface functional groups on Cr(Ⅵ) removal by activated carbon from aqueous solution 被引量:9
18
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)
在线阅读 下载PDF
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
19
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
原文传递
Biomass Allocation Patterns of Alpine Grassland Species and Functional Groups along a Precipitation Gradient on the Northern Tibetan Plateau 被引量:8
20
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
原文传递
上一页 1 2 246 下一页 到第
使用帮助 返回顶部