Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore th...Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving method.Under the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable approach.Then,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are presented.To demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also given.On this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried out.The results show the accuracy and efficiency of the TMM.展开更多
BACKGROUND Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level,circular RNAs(circRNAs)participate in the pathogenesis of ...BACKGROUND Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level,circular RNAs(circRNAs)participate in the pathogenesis of a variety of diseases and are considered ideal biomarkers of human disease.AIM To examine the expression of circRNA_103516 in inflammatory bowel disease(IBD)and its associations with clinical phenotypes and inflammatory cytokines.METHODS Peripheral blood mononuclear cells(PBMCs)were obtained from patients with IBD,healthy controls(HCs),and patient controls(PCs).Expression of circRNA_103516 and hsa-miR-19b-1-5p was assessed by quantitative reverse transcription-polymerase chain reaction.Crohn's disease activity index(CDAI),Mayo score,C-reactive protein(CRP)level,and erythrocyte sedimentation rate(ESR)were measured.To assess the inflammatory cytokines tumour necrosis factorα(TNF-α),interferon-γ(IFN-γ),and interleukin-10(IL-10),blood samples were analysed by flow cytometry.RESULTS Ninety Crohn’s disease(CD)and 90 ulcerative colitis(UC)patients,80 HCs,and 35 PCs were included in the study.CircRNA_103516 was upregulated in CD and UC patients compared with HCs and PCs(P<0.05).The area under the curve of circRNA_103516 for diagnosing CD and UC was 0.790 and 0.687,respectively.In addition,circRNA_103516 levels were increased in active CD and UC compared with remittent groups(P=0.027,P=0.045).Furthermore,in CD,circRNA_103516 correlated positively with CDAI(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),and IFN-γ(P<0.001)and negatively correlated with IL-10(P=0.006).In UC patients,circRNA_103516 correlated with Mayo score(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),IFN-γ(P=0.011),and IL-10(P=0.002).Additionally,circRNA_103516 correlated positively with stricturing(P=0.018)and penetrating(P=0.031)behaviour.Moreover,hsamiR-19b-1-5p correlated negatively with circRNA_103516 in CD.CONCLUSION CircRNA_103516 levels in PBMCs can be considered an ideal candidate biomarker for diagnosing IBD.Dysregulation of circRNA_103516 may participate in the molecular mechanism of IBD through hsa-miR-19b-1-5p sponging.展开更多
BACKGROUND The incidence of inflammatory bowel disease,a chronic intestinal inflammatory disorder that includes Crohn’s disease(CD)and ulcerative colitis,is rising.Circular RNAs are considered valuable diagnostic bio...BACKGROUND The incidence of inflammatory bowel disease,a chronic intestinal inflammatory disorder that includes Crohn’s disease(CD)and ulcerative colitis,is rising.Circular RNAs are considered valuable diagnostic biomarkers for CD.Current evidence supports the views that epithelial-mesenchymal transition(EMT)plays an important role in CD pathogenesis,and that hsa-miR-130a-3p can inhibit transforming growth factor-β1(TGF-β1)-induced EMT.Our previous study revealed that hsa_circRNA_102610 was upregulated in CD patients.Moreover,we predicted an interaction between hsa_circRNA_102610 and hsa-miR-130a-3p.Thus,we hypothesized that hsa_circRNA_102610 may play roles in the proliferation and EMT of intestinal epithelial cells by sponging hsa-miR-130a-3p to participate in the pathogenesis of CD.AIM To explore the mechanism of hsa_circRNA_102610 in the pathogenesis of CD.METHODS The relative expression levels of hsa_circRNA_102610 and hsa-miR-130a-3p in patients were detected by quantitative reverse transcription-polymerase chain reaction.The proliferation of human intestinal epithelial cells(HIECs)and normal-derived colon mucosa cell line 460(NCM460)cells was detected by cell counting kit-8,5-ethynyl-2’-deoxyuridine staining and cell cycle assays following overexpression or downregulation of hsa_circRNA_102610.Cell proliferation assays were performed as described above in a rescue experiment with hsa-miR-130a-3p mimics.The interaction of hsa_circRNA_102610 and hsa-miR-130a-3p was verified by fluorescence in situ hybridization and dual luciferase reporter assays.The relative expression levels of CyclinD1,mothers against decapentaplegic homolog 4(SMAD4),E-cadherin,N-cadherin and Vimentin were detected by western blotting following hsa_circRNA_102610 overexpression,TGF-β1-induced EMT or hsa-miR-130a-3p mimic transfection(in rescue experiments).RESULTS Upregulation of hsa_circRNA_102610 was determined to be positively correlated with elevated fecal calprotectin levels in CD(r=0.359,P=0.007)by Pearson correlation analysis.Hsa_circRNA_102610 promoted the proliferation of HIECs and NCM460 cells,while hsa-miR-130a-3p reversed the cell proliferationpromoting effects of hsa_circRNA_102610.Fluorescence in situ hybridization and dual luciferase reporter assays showed that hsa_circRNA_102610 directly bound hsa-miR-130a-3p in NCM460 and 293T cells.An inverse correlation between downregulation of hsa-miR-130a-3p and upregulation of hsa_circRNA_102610 in CD patients was observed(r=-0.290,P=0.024)by Pearson correlation analysis.Moreover,overexpression of hsa_circRNA_102610 promoted SMAD4 and CyclinD1 protein expression validated by western-blotting.Furthermore,overexpression of hsa_circRNA_102610 promoted TGF-β1 induced EMT in HIECs and NCM460 cells via targeting of hsa-miR-130a-3p,with increased expression of Vimentin and N-cadherin and decreased expression of E-cadherin.CONCLUSION Hsa_circRNA_102610 upregulation in CD patients could promote the proliferation and EMT of intestinal epithelial cells via sponging of hsa-miR-130a-3p.展开更多
In this study, the CERES(Crop Estimation through Resource and Environment Synthesis) crop model was coupled with CLM3.5, the land module of the regional climate model RegCM4. The new coupled model was named RegCM4_CER...In this study, the CERES(Crop Estimation through Resource and Environment Synthesis) crop model was coupled with CLM3.5, the land module of the regional climate model RegCM4. The new coupled model was named RegCM4_CERES; and in this model, crop type was further divided into winter wheat, spring wheat, spring maize, summer maize, early rice, late rice,single rice, and other crop types based on each distribution fraction. The development of each crop sub-type was simulated by the corresponding crop model separately, with each planting and harvesting date. A simulation test using RegCM4_CERES was conducted across China from 1999 to 2008; a control test was also performed using the original RegCM4. Data on crop LAI(leaf area index), soil moisture at 10 cm depth, precipitation, and 2 m air temperature were collected to evaluate the performance of RegCM4_CERES. The evaluation provided comparison of single-station time series, regional distributions,seasonal variations, and statistical indices for RegCM4_CERES. The results revealed that the coupled model had an excellent ability to simulate the phonological changes and spatial variations in crops. The consideration of dynamic crop development in RegCM4_CERES corrected the wet bias of the original RegCM4 over North China and the cold bias over South China.However, the degree of improvement was minimal and the statistical indices for RegCM4_CERES were roughly the same as the original RegCM4.展开更多
Lithium ion batteries(LIBs)have been widely used in portable and smart devices because of their high energy densities,long cycle life and environmental friendliness.In order to meet the evergrowing demand for human-be...Lithium ion batteries(LIBs)have been widely used in portable and smart devices because of their high energy densities,long cycle life and environmental friendliness.In order to meet the evergrowing demand for human-beings utilizing electronic devices,electric vehicles and energy storage grids.展开更多
Synaptosomal-associated protein-25 is an important factor for synaptic functions and cognition. In this study, subarachnoid hemorrhage models with spatial learning disorder were established through a blood injection i...Synaptosomal-associated protein-25 is an important factor for synaptic functions and cognition. In this study, subarachnoid hemorrhage models with spatial learning disorder were established through a blood injection into the chiasmatic cistern. Immunohistochemical staining and western blot analysis results showed that synaptosomal-associated protein-25 expression in the temporal lobe, hippocampus, and cerebellum significantly lower at days 1 and 3 following subarachnoid hemorrhage. Our findings indicate that synaptosomal-associated protein-25 expression was down-regulated in the rat brain after subarachnoid hemorrhage.展开更多
While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and st...While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and stability of the oxygen reduction reaction are yet to be fully studied.Here,the effect of A-site doping on the oxygen reduction reaction activity and stability has been studied by evaluating the performance of both symmetrical and single cells.It is shown that Ca-doped PBC(PrBa_(0.8)Ca_(0.2)Co_(2)O_(6),PBCC)shows a slightly smaller polarization resistance(0.076Ωcm^(2))than that(0.085Ωcm^(2))of Sr-doped PBC(PrBa0.8Sr0.2Co2O6,PBSC)at 700◦C in wet air.Moreover,the degradation rate of PBCC is 0.0003Ωcm^(2)h^(−1)(0.3%h−1)in 100 h,about 1/10 of that of PBSC at 700◦C in wet air.In addition,it is also confirmed that single cells with PBCC cathode show higher peak power density(1.22Wcm^(−2)vs.1.08Wcm^(−2)at 650◦C)and better durability(degradation rate of 0.1%h^(−1)vs.0.13%h^(−1))than those with PBSC cathode.The distribution of relaxation time analyses suggests that the better stability of the PBCC electrode may come from the fast and stable surface oxygen exchange process in the medium frequency range of the electrochemical impedance spectrum.展开更多
Photocatalytic nitrogen fixation has been explored as a feasible pathway for ammonia synthesis.How-ever,the convenient and efficient preparation of photocatalysts for nitrogen fixation remains a challenge.Meanwhile,th...Photocatalytic nitrogen fixation has been explored as a feasible pathway for ammonia synthesis.How-ever,the convenient and efficient preparation of photocatalysts for nitrogen fixation remains a challenge.Meanwhile,the reaction pathway and mechanism of photocatalytic nitrogen fixation are unclear.Herein,single-atom Fe-porous g-C_(3)N_(4)(FPx)samples were manufactured using a one-step anneal technique via bubble template and direct metal atomization.Characterization results indicate that FPx has a porous structure and single-atom Fe.The porous structure exposed more active centers.Simultaneously,single-atom Fe changes the adsorption mode of N_(2)from physical to chemical and turns the photocatalytic ni-trogen fixation from the associative distal pathway to the associative alternating pathway.Consequently,without any sacrificial agent or cocatalysts,FPx presents a prominent increase in photocatalytic activ-ity,reaching 62.42μmol h^(−1)g^(−1),over fivefold larger than that of bulk g-C_(3)N_(4).This work provides new insights into photocatalytic nitrogen fixation and achieves efficient N_(2)photoreduction by constructing single-atom photocatalysts.展开更多
基金the National Natural Science Foundation of China(Nos.12302007,12372006,and 12202109)the Specific Research Project of Guangxi for Research Bases and Talents(No.AD23026051)。
文摘Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving method.Under the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable approach.Then,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are presented.To demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also given.On this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried out.The results show the accuracy and efficiency of the TMM.
基金Supported by the Natural Science Foundation of Jiangsu Province,No.BK20161232the Suzhou Special Project of Diagnosis and Treatment for Key Clinical Disease,No.LCZX201715
文摘BACKGROUND Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level,circular RNAs(circRNAs)participate in the pathogenesis of a variety of diseases and are considered ideal biomarkers of human disease.AIM To examine the expression of circRNA_103516 in inflammatory bowel disease(IBD)and its associations with clinical phenotypes and inflammatory cytokines.METHODS Peripheral blood mononuclear cells(PBMCs)were obtained from patients with IBD,healthy controls(HCs),and patient controls(PCs).Expression of circRNA_103516 and hsa-miR-19b-1-5p was assessed by quantitative reverse transcription-polymerase chain reaction.Crohn's disease activity index(CDAI),Mayo score,C-reactive protein(CRP)level,and erythrocyte sedimentation rate(ESR)were measured.To assess the inflammatory cytokines tumour necrosis factorα(TNF-α),interferon-γ(IFN-γ),and interleukin-10(IL-10),blood samples were analysed by flow cytometry.RESULTS Ninety Crohn’s disease(CD)and 90 ulcerative colitis(UC)patients,80 HCs,and 35 PCs were included in the study.CircRNA_103516 was upregulated in CD and UC patients compared with HCs and PCs(P<0.05).The area under the curve of circRNA_103516 for diagnosing CD and UC was 0.790 and 0.687,respectively.In addition,circRNA_103516 levels were increased in active CD and UC compared with remittent groups(P=0.027,P=0.045).Furthermore,in CD,circRNA_103516 correlated positively with CDAI(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),and IFN-γ(P<0.001)and negatively correlated with IL-10(P=0.006).In UC patients,circRNA_103516 correlated with Mayo score(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),IFN-γ(P=0.011),and IL-10(P=0.002).Additionally,circRNA_103516 correlated positively with stricturing(P=0.018)and penetrating(P=0.031)behaviour.Moreover,hsamiR-19b-1-5p correlated negatively with circRNA_103516 in CD.CONCLUSION CircRNA_103516 levels in PBMCs can be considered an ideal candidate biomarker for diagnosing IBD.Dysregulation of circRNA_103516 may participate in the molecular mechanism of IBD through hsa-miR-19b-1-5p sponging.
基金Supported by the Suzhou Special Project of Diagnosis and Treatment for Key Clinical Disease,No.LCZX201715the Natural Science Foundation of Jiangsu Province,No.BK20161232the Science and Technology Development Fund of Nanjing Medical University,No.NMUB2018215.
文摘BACKGROUND The incidence of inflammatory bowel disease,a chronic intestinal inflammatory disorder that includes Crohn’s disease(CD)and ulcerative colitis,is rising.Circular RNAs are considered valuable diagnostic biomarkers for CD.Current evidence supports the views that epithelial-mesenchymal transition(EMT)plays an important role in CD pathogenesis,and that hsa-miR-130a-3p can inhibit transforming growth factor-β1(TGF-β1)-induced EMT.Our previous study revealed that hsa_circRNA_102610 was upregulated in CD patients.Moreover,we predicted an interaction between hsa_circRNA_102610 and hsa-miR-130a-3p.Thus,we hypothesized that hsa_circRNA_102610 may play roles in the proliferation and EMT of intestinal epithelial cells by sponging hsa-miR-130a-3p to participate in the pathogenesis of CD.AIM To explore the mechanism of hsa_circRNA_102610 in the pathogenesis of CD.METHODS The relative expression levels of hsa_circRNA_102610 and hsa-miR-130a-3p in patients were detected by quantitative reverse transcription-polymerase chain reaction.The proliferation of human intestinal epithelial cells(HIECs)and normal-derived colon mucosa cell line 460(NCM460)cells was detected by cell counting kit-8,5-ethynyl-2’-deoxyuridine staining and cell cycle assays following overexpression or downregulation of hsa_circRNA_102610.Cell proliferation assays were performed as described above in a rescue experiment with hsa-miR-130a-3p mimics.The interaction of hsa_circRNA_102610 and hsa-miR-130a-3p was verified by fluorescence in situ hybridization and dual luciferase reporter assays.The relative expression levels of CyclinD1,mothers against decapentaplegic homolog 4(SMAD4),E-cadherin,N-cadherin and Vimentin were detected by western blotting following hsa_circRNA_102610 overexpression,TGF-β1-induced EMT or hsa-miR-130a-3p mimic transfection(in rescue experiments).RESULTS Upregulation of hsa_circRNA_102610 was determined to be positively correlated with elevated fecal calprotectin levels in CD(r=0.359,P=0.007)by Pearson correlation analysis.Hsa_circRNA_102610 promoted the proliferation of HIECs and NCM460 cells,while hsa-miR-130a-3p reversed the cell proliferationpromoting effects of hsa_circRNA_102610.Fluorescence in situ hybridization and dual luciferase reporter assays showed that hsa_circRNA_102610 directly bound hsa-miR-130a-3p in NCM460 and 293T cells.An inverse correlation between downregulation of hsa-miR-130a-3p and upregulation of hsa_circRNA_102610 in CD patients was observed(r=-0.290,P=0.024)by Pearson correlation analysis.Moreover,overexpression of hsa_circRNA_102610 promoted SMAD4 and CyclinD1 protein expression validated by western-blotting.Furthermore,overexpression of hsa_circRNA_102610 promoted TGF-β1 induced EMT in HIECs and NCM460 cells via targeting of hsa-miR-130a-3p,with increased expression of Vimentin and N-cadherin and decreased expression of E-cadherin.CONCLUSION Hsa_circRNA_102610 upregulation in CD patients could promote the proliferation and EMT of intestinal epithelial cells via sponging of hsa-miR-130a-3p.
基金financially supported by the National Key R&D Program of China (Grant No. 2017 YFA0603702)the National Natural Science Foundation (Grant Nos. 41705046, 41606112 and 41571019)the Key Research and Development Program of Shandong Province of China (Grant No. 2016JMRH0538)
文摘In this study, the CERES(Crop Estimation through Resource and Environment Synthesis) crop model was coupled with CLM3.5, the land module of the regional climate model RegCM4. The new coupled model was named RegCM4_CERES; and in this model, crop type was further divided into winter wheat, spring wheat, spring maize, summer maize, early rice, late rice,single rice, and other crop types based on each distribution fraction. The development of each crop sub-type was simulated by the corresponding crop model separately, with each planting and harvesting date. A simulation test using RegCM4_CERES was conducted across China from 1999 to 2008; a control test was also performed using the original RegCM4. Data on crop LAI(leaf area index), soil moisture at 10 cm depth, precipitation, and 2 m air temperature were collected to evaluate the performance of RegCM4_CERES. The evaluation provided comparison of single-station time series, regional distributions,seasonal variations, and statistical indices for RegCM4_CERES. The results revealed that the coupled model had an excellent ability to simulate the phonological changes and spatial variations in crops. The consideration of dynamic crop development in RegCM4_CERES corrected the wet bias of the original RegCM4 over North China and the cold bias over South China.However, the degree of improvement was minimal and the statistical indices for RegCM4_CERES were roughly the same as the original RegCM4.
基金financial support from the“Young Talent Fellowship”program through South China University of Technologythe Fundamental Research Funds for the Central Universities(2018JQ06)。
文摘Lithium ion batteries(LIBs)have been widely used in portable and smart devices because of their high energy densities,long cycle life and environmental friendliness.In order to meet the evergrowing demand for human-beings utilizing electronic devices,electric vehicles and energy storage grids.
基金supported by grants from the National Natural Science Foundation of China,No.81171105,81271300,and 81100872Jiangsu Provincial Outstanding Medical Academic Leader Program,No.LJ201139+2 种基金the National Key Technology Research & Development Program for the Twelfth Five-year Plan of China,No.2011BAI08B05 and 2011BAI08B06grants from Education Department of Jiangsu Province,No.11KJB320011a grant from Suzhou Government,No.SYS201109
文摘Synaptosomal-associated protein-25 is an important factor for synaptic functions and cognition. In this study, subarachnoid hemorrhage models with spatial learning disorder were established through a blood injection into the chiasmatic cistern. Immunohistochemical staining and western blot analysis results showed that synaptosomal-associated protein-25 expression in the temporal lobe, hippocampus, and cerebellum significantly lower at days 1 and 3 following subarachnoid hemorrhage. Our findings indicate that synaptosomal-associated protein-25 expression was down-regulated in the rat brain after subarachnoid hemorrhage.
基金Natural Science Foundation of Guangdong Province,Grant/Award Number:2021A1515010395Fundamental Research Funds for the Central Universities,Grant/Award Number:2022ZYGXZR002+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:22179039,22005105Pearl River Talent Recruitment Program,Grant/Award Number:2019QN01C693Guangdong Innovative and Entrepreneurial Research Team Program,Grant/Award Number:2021ZT09L392。
文摘While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and stability of the oxygen reduction reaction are yet to be fully studied.Here,the effect of A-site doping on the oxygen reduction reaction activity and stability has been studied by evaluating the performance of both symmetrical and single cells.It is shown that Ca-doped PBC(PrBa_(0.8)Ca_(0.2)Co_(2)O_(6),PBCC)shows a slightly smaller polarization resistance(0.076Ωcm^(2))than that(0.085Ωcm^(2))of Sr-doped PBC(PrBa0.8Sr0.2Co2O6,PBSC)at 700◦C in wet air.Moreover,the degradation rate of PBCC is 0.0003Ωcm^(2)h^(−1)(0.3%h−1)in 100 h,about 1/10 of that of PBSC at 700◦C in wet air.In addition,it is also confirmed that single cells with PBCC cathode show higher peak power density(1.22Wcm^(−2)vs.1.08Wcm^(−2)at 650◦C)and better durability(degradation rate of 0.1%h^(−1)vs.0.13%h^(−1))than those with PBSC cathode.The distribution of relaxation time analyses suggests that the better stability of the PBCC electrode may come from the fast and stable surface oxygen exchange process in the medium frequency range of the electrochemical impedance spectrum.
基金supported by the Jiangxi Provincial Natural Science Foundation(No.20224BAB213016)Jiangxi Province tech-nology innovation guidance project(grant No.20212BDH81036)Science and Technology Project of the Education Department of Jiangxi Province(No.GJJ200457).
文摘Photocatalytic nitrogen fixation has been explored as a feasible pathway for ammonia synthesis.How-ever,the convenient and efficient preparation of photocatalysts for nitrogen fixation remains a challenge.Meanwhile,the reaction pathway and mechanism of photocatalytic nitrogen fixation are unclear.Herein,single-atom Fe-porous g-C_(3)N_(4)(FPx)samples were manufactured using a one-step anneal technique via bubble template and direct metal atomization.Characterization results indicate that FPx has a porous structure and single-atom Fe.The porous structure exposed more active centers.Simultaneously,single-atom Fe changes the adsorption mode of N_(2)from physical to chemical and turns the photocatalytic ni-trogen fixation from the associative distal pathway to the associative alternating pathway.Consequently,without any sacrificial agent or cocatalysts,FPx presents a prominent increase in photocatalytic activ-ity,reaching 62.42μmol h^(−1)g^(−1),over fivefold larger than that of bulk g-C_(3)N_(4).This work provides new insights into photocatalytic nitrogen fixation and achieves efficient N_(2)photoreduction by constructing single-atom photocatalysts.