Response surface methodology(RSM) was employed to optimize the control parameters of TiO_2/graphene with exposed {001} facets during synthesis, and its enhanced photocatalytic activities were evaluated in the photodeg...Response surface methodology(RSM) was employed to optimize the control parameters of TiO_2/graphene with exposed {001} facets during synthesis, and its enhanced photocatalytic activities were evaluated in the photodegradation of toluene. Experimental results were in good agreement with the predicted results obtained using RSM with a correlation coefficient(R^2) of 0.9345. When 22.06 mg of graphite oxide(GO) and 2.09 mL of hydrofluoric acid(HF) were added and a hydrothermal time of 28 h was used, a maximum efficiency in the degradation of toluene was achieved. X-ray diffraction(XRD), transmission electron microscopy(TEM), and scanning electron microscopy(SEM) were employed to characterize the obtained hybrid photocatalyst. The electron transferred between Ti and C retarded the combination of electron–hole pairs and hastened the transferring of electrons, which enhanced the photocatalytic activity.展开更多
The highly conserved abundant nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) is activated by DNA damage. PARP-1 activation is associated in DNA repair, cell death and inflammation. Since oxidative stress ...The highly conserved abundant nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) is activated by DNA damage. PARP-1 activation is associated in DNA repair, cell death and inflammation. Since oxidative stress induced robust DNA damage and wide spread inflamma- tory responses are common pathologies of various CNS diseases, the attention towards PARP-1 as a therapeutic target has been amplifying. This review highlights the multiple roles of PARP- 1 in neurological diseases and po- tential of PARP- 1 inhibitors to enter clinical translation.展开更多
Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The re...Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The researcher recruited 24 participants and assigned six simulated work task situations to each of them. Each experiment lasted around 2 hours and was recorded by the software tool Morae.Findings: Time(frequency) and time(length) are more closely related to user’s selection and query-related behavior compared to the facet ‘process’ of work task. Knowledge level of work task topic, degree of work task difficulty, and subjective work task complexity are significantly correlated with selection and query-related behavior. Work task difficulty and work task complexity are different concepts. Subjective work task complexity, work task difficulty, and knowledge of work task topic are significantly correlated with user’s selection and query-related behavior.Research limitations/implications: The limitations of this study include a small sample size,limited work task situations, and possible spurious relationships. This study has implications in informing task-based information seeking/search/retrieval research and interactive information retrieval(IIR) systems design.Originality/values: Previous studies usually did not touch upon how different facets of work tasks affected interactive activities. Some studies examining task complexity and information behavior were concerned with how work tasks affect users’ behavior at information-seeking level, rather than at information search level. This study makes contribution to interactive information retrieval,task-based information search and retrieval, and personalization of IR.展开更多
This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated (001) facets for toluene degradation. The performance of photocatalyst wa...This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated (001) facets for toluene degradation. The performance of photocatalyst was tested on a home-made volatile organic compounds degradation system. The ozone modification, toluene adsorption and degradation mecha-nism were established by a combination of various characterization methods, in situ diuse reectance infrared fourier transform spectroscopy, and density functional theory calculation. The surface modtication with ozone can signiticantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5c-Ti sites on (001) facets act as the adsorption sites for ozone. The formed Ti-O bonds reacted with H2O to generate a large amount of isolated Ti5c-OH which act as the adsorption sites for toluene, and thus signi- cantly increase the adsorption capacity for toluene. The outstanding photo- catalytic performance of ozone-modified TiO2 is due to its high adsorption ability for toluene and the abundant surface hydroxyl groups, which produce very reactive OH· radicals under irradiation. Furthermore, the O2 generated via ozone dissociation could combine with the photogenerated electrons to form superoxide radicals which are also conductive to the toluene degradation.展开更多
S-doped Sb_2O_3 nanocrystals were synthesized using SbCl3 and thioacetamide(TAA) as starting materials by a hydrothermal method and the effects of TAA dosage on the composition and properties of resultant nanocrysta...S-doped Sb_2O_3 nanocrystals were synthesized using SbCl3 and thioacetamide(TAA) as starting materials by a hydrothermal method and the effects of TAA dosage on the composition and properties of resultant nanocrystals were determined.Their photocatalytic performance was evaluated using the degradation of methyl orange(MO) as a model reaction.The results suggest that TAA dosage can affect the preferential growth direction of Sb_2O_3,and further influences its photocatalytic activity.S doping can extend the optical absorption edge of Sb_2O_3 to the visible light religion,and thus endows its ability to photocatalyze the degradation of MO under visible light illumination.Based on these results,the correlations between the photocatalytic activity of S-doped Sb_2O_3 and the ratio between exposed facets,specific surface area and crystallographic defects were discussed.展开更多
Let M be a matroid defined on a finite set E and L?⊂?E?. L is locked in M if??and ?are 2-connected, and . In this paper, we prove that the nontrivial facets of the bases polytope of M are described by the lo...Let M be a matroid defined on a finite set E and L?⊂?E?. L is locked in M if??and ?are 2-connected, and . In this paper, we prove that the nontrivial facets of the bases polytope of M are described by the locked subsets. We deduce that finding the maximum-weight basis of M is a polynomial time problem for matroids with a polynomial number of locked subsets. This class of matroids is closed under 2-sums and contains the class of uniform matroids, the Vámos matroid and all the excluded minors of 2-sums of uniform matroids. We deduce also a matroid oracle for testing uniformity of matroids after one call of this oracle.展开更多
The manipulation of the surface property of WO_(3) photoanode is the main breakthrough direction to improve its solar water oxidation performance both in thermodynamics and kinetics.Here,we report a WO_(3)(002)/m-WO_(...The manipulation of the surface property of WO_(3) photoanode is the main breakthrough direction to improve its solar water oxidation performance both in thermodynamics and kinetics.Here,we report a WO_(3)(002)/m-WO_(3) homojunction film that is composed of an upper WO_(3) layer with predominant(002)facet(WO_(3)(002))and a lower WO_(3) layer with multi-crystal facets(m-WO_(3))as a photoanode for solar water oxidation.Due to the synergistic effect of WO_(3)(002)layer and m-WO_(3) layer,better water oxidation activity and stability are achieved on the WO_(3)(002)/m-WO_(3) homojunction film relative to the m-WO_(3) and WO_(3)(002)film.Specifically,the improved water oxidation performance on the WO_(3)(002)/m-WO_(3) homojunction film is attributed to the followings.In thermodynamics,the band position differences between WO_(3)(002)layer and m-WO_(3) layer lead to the formation of WO_(3)(002)/m-WO_(3) homojunction,which has positive function of improving their charge separation and transfer.In kinetics,the upper WO_(3)(002)layer of the WO_(3)(002)/m-WO_(3) film has superior activity in the adsorption and activation of water molecules,water oxidation on this homojunction film photoanode is inclined to follow the four-holes pathway,and the corrosion of photoanode from the H_(2)O_(2) intermediate is restrained.The present work provides a new strategy to modify the WO_(3) photoanodes for thermodynamically and kinetically efficient water oxidation.展开更多
Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies o...Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies of S atoms on different facets as well as the surface energies of Co_(2)P indicate that the HIFs become more stable after adsorbing S atoms.With rich unsaturated sites on HIFs,the photochemical reduction rate of CO_(2)over Co_(2)P NRs is 14.5 mmol h^(-1)g^(-1)for the production of CO within 3 h.The analysis of electron transfer,bond lengths,bond angles and adsorption energies indicate that the CO_(2)molecules are more easily adsorbed and activated on the HIFs.The free energy calculations and d band theory demonstrate that the HIFs are conducive to reducing the formation energy barriers as well as improving the stability of the intermediate^(*)COOH,then enhancing the catalytic performance of CO_(2)reduction.展开更多
Non-carious cervical lesions (NCCLs) are defined as the loss of dental hard tissue at the cement-enamel junction. Erosion, abrasion, and attrition have been associated with this disorder. Objective: Recently, occlusal...Non-carious cervical lesions (NCCLs) are defined as the loss of dental hard tissue at the cement-enamel junction. Erosion, abrasion, and attrition have been associated with this disorder. Objective: Recently, occlusal stress causing of cervical enamel cracks (abfraction) has been considered as an additional etiology for NCCLs to facilitate the erosion and abrasion mechanisms in tooth wear. Study Design: The prevalence of NNCLs and wear facets in a population with permanent dentition in absence of any clear etiological factors related to erosion and abrasion causes is evaluated. A total 295 subjects are enrolled for this study and divided into four age groups (subjects aged 15 - 27 years, 28 - 42 years, 43 - 57 years and 58 - 75 years respectively). An overall of 6629 teeth are investigated to find NCCLs and wear facets. The occlusion is analyzed in each patient. Results: An overall of 801 teeth (12%) show NCCLs and 623 of them (78%) highlight also wear facets. The higher number of teeth with NCCLs and of these with simultaneous presence also of wear facets are found on teeth of patients of group-3 (11% of all teeth examined for group and 81% respectively) and to group-4 (24.4% of all teeth examined for group and 86.5% respectively) of remaining teeth without NCCLs (5828) only 138 (2.4%) shown wear facets. Conclusion: The results of this study held the occlusal forces as the main cause of NCCLs on teeth in presence of wear facets.展开更多
Localized CdS homojunctions with optimal ratio of high and low index facets are constructed to dy-namically boost H_(2)O splitting into H_(2)energy by hydrothermal method in combination with calcination.By density fun...Localized CdS homojunctions with optimal ratio of high and low index facets are constructed to dy-namically boost H_(2)O splitting into H_(2)energy by hydrothermal method in combination with calcination.By density functional theory,hall effect,and in situ diffuse reflectance infrared Fourier transform spec-troscopy,it is revealed that photo-irradiated e^(−)and h^(+)can be spatially separated and directionally trans-ferred to the reductive high-index facet{002}and oxidative low-index facet{110}of localized CdS homo-junction induced by Fermi level difference of both high and low index facets to dehydrogenate ^(∗)-OH and coupled ^(∗)-O intermediates for H_(2)and O_(2)yield,respectively,along with a solar conversion into hydrogen of 1.93%by AM 1.5 G irradiation at 65℃.The study work suggests a scientific perspective on the optimal ratio of high and low index facets to understand photo-generated charge carrier transfer dynamically and their photocatalytic principle for H_(2)O splitting reaction in kinetics.展开更多
It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation...It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,respectively.In such cases,only one family of facets can be used for photocatalytic hydrogen evolution.Herein,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all facets.The photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}facets.Thus,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.展开更多
Cu-based electrocatalysts with favorable facets and Cu^(+)can boost CO_(2) reduction to valuable multicarbon products.However,the inevitable Cu^(+)reduction and the phase evolution usually result in poor performance.H...Cu-based electrocatalysts with favorable facets and Cu^(+)can boost CO_(2) reduction to valuable multicarbon products.However,the inevitable Cu^(+)reduction and the phase evolution usually result in poor performance.Herein,we fabricate CuI nanodots with favorable(220)facets and a stable Cu^(+)state,accomplished by operando reconstruction of Cu(OH)_(2) under CO_(2)-and I--containing electrolytes for enhanced CO_(2)-to-C_(2)H_(4) conversion.Synchrotron X-ray absorption spectroscopy(XAS),in-situ Raman spectroscopy and thermodynamic potential analysis reveal the preferred formation of CuI.Vacuum gas electroresponse and density functional theory(DFT)calculations reveal that CO_(2)-related species induce the exposure of the(220)plane of Cu I.Moreover,the small size of nanodots enables the adequate contact with I^(-),which guarantees the rapid formation of Cu I instead of the electroreduction to Cu^(0).As a result,the resulting catalysts exhibit a high C2H4 Faradaic efficiency of 72.4%at a large current density of 800 m A cm^(-2) and robust stability for 12 h in a flow cell.Combined in-situ ATR-SEIRS spectroscopic characterizations and DFT calculations indicate that the(220)facets and stable Cu^(+) in CuI nanodots synergistically facilitate CO_(2)/*CO adsorption and*CO dimerization.展开更多
To achieve a complete industrial chain of hydrogen energy,the development of efficient electrocatalysts for hydrogen evolution reaction(HER)is of great concerns.Herein,a nickel nitride supported platinum(Pt)catalyst w...To achieve a complete industrial chain of hydrogen energy,the development of efficient electrocatalysts for hydrogen evolution reaction(HER)is of great concerns.Herein,a nickel nitride supported platinum(Pt)catalyst with highly exposed Pt(110)facets(Pt_((110))-Ni_(3)N)is obtained for catalyzing HER.Combined X-ray spectra and density functional theory studies demonstrate that the interfacial electronic interaction between Pt and Ni3N support can promote the hydrogen evolution on Pt(110)facets by weakening hydrogen adsorption.As a result,the Pt_((110))-Ni_(3)N catalyst delivers an obviously higher specific activity than commercial 20 wt.%Pt/C in acidic media.This work suggests that the suitable interface modulation may play a vital role in rationally designing advanced electrocatalysts.展开更多
The development of thermodynamically controllable synthetic strategy to manipulate the morphology of ZIF-8 without capping agent is essential to help understanding their facet effect and the structure-activity relatio...The development of thermodynamically controllable synthetic strategy to manipulate the morphology of ZIF-8 without capping agent is essential to help understanding their facet effect and the structure-activity relationship of single atom catalysts derived from ZIF-8.Here,we prepared ZIF-8 with different morphologies(cube,truncated rhombododecahedral and rhombododecahedral)and thus area ratio of exposed{100},{110}facets by a thermodynamically controllable synthetic strategy.When the reaction proceeds under room temperature(30℃),the assembling of ZIF-8 followed an area-reducing layered growth mode,while switched to an integral layered growth mode at lower temperature-40℃.Moreover,this strategy also works to obtain ZIF-8 encapsulated with metal precursors(Fe(acac)_(3),Cu(acac)_(2)and Co(acac)_(2)).Single Fe atom anchored on nitrogen doped carbon catalysts(SA-Fe/CN)derived from Fe-ZIF-8 retain their original morphologies and the unsaturated surface-active sites on{100}facet,which further displays different catalytic performance towards oxygen reduction reaction(ORR).This work not only reveals the different growth pattern of ZIF-8,but also points out a new direction for designing and synthesizing MOFs with different morphology rationally.展开更多
Natural photosynthesis,which provides a green and high-efficiency energy conversion path by spatial separation of photogenerated carriers through combined actions of molecules ingeniously arranged in an efficient sola...Natural photosynthesis,which provides a green and high-efficiency energy conversion path by spatial separation of photogenerated carriers through combined actions of molecules ingeniously arranged in an efficient solar nanospace,highlights the importance of rational nanostructure design to realize artificial high-efficiency photosystem.Inspired by these unique features,we constructed a high-efficiency ternary photosystem by selectively decorating the{001}facets of 18-facet SrTiO_(3)with Au@CdS photosensitizers via a green photo-assisted method.Benefiting from the dual-facilitated charge carriers transportation in core-shell structured Au@CdS heterojunction and well-faceted 18-facet SrTiO_(3)nanocrystal,such a photo-catalyst could realize the effective spatial separation of photogenerated electrons and holes.As expected,the 18-facet SrTiO_(3)/Au@CdS photocatalyst exhibits superior activity in visible-light-driven photocatalytic hydrogen evolution(4.61 mmol h^(−1)g^(−1)),166%improvement in comparison with randomly deposited Au@CdS(1.73 mmol h^(−1)g^(−1)).This work offers new insight into the development of green and high-efficiency photocatalytic systems based on the rational nanostructure design by crystal facet engineering.展开更多
Noble-metal nanocrystals enclosed by high-index facets are of growing interest due to their enhanced catalytic performance in a variety of reactions.Herein,we report the deterministic synthesis of Pd nanocrystals enca...Noble-metal nanocrystals enclosed by high-index facets are of growing interest due to their enhanced catalytic performance in a variety of reactions.Herein,we report the deterministic synthesis of Pd nanocrystals encased by high-index facets by controlling the rate of deposition(V_(deposition))relative to that of surface diffusion(V_(diffusion)).For octahedral seeds with truncated corners,a reduction rate(and thus deposition rate)faster than that of surface diffusion(i.e.,V_(deposition)/V_(diffusion)>1)led to the formation of concave trisoctahedra(TOH)with high-index facets.When the reduction was slowed down,in contrast,surface diffusion dominated the growth pathway.In the case of V_(deposition)/V_(diffusion)≈1,truncated octahedra with enlarged sizes were produced.When the reduction rate was between these two extremes,we obtained concave tetrahexahedra(THH)without or with truncation.Similar growth patterns were also observed for the cuboctahedral seeds.When the Pd octahedra,concave TOH,and concave THH were tested for electrocatalyzing the formic acid oxidation(FAO)reaction,those with high-index facets were advantageous over the conventional Pd octahedra enclosed by{111}facets.This work not only contributes to the understanding of surface diffusion and its role in nanocrystal growth but also offers a general protocol for the synthesis of nanocrystals enclosed by high-index facets.展开更多
Orthorhombic Nb_(2)O_(5)(T-Nb_(2)O_(5))is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion storage.Herein,F-doped T-Nb_(2)O_(5) microflowers(F-Nb_(...Orthorhombic Nb_(2)O_(5)(T-Nb_(2)O_(5))is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion storage.Herein,F-doped T-Nb_(2)O_(5) microflowers(F-Nb_(2)O_(5))are rationally synthesized through topotactic conversion.Specifically,F-Nb_(2)O_(5) are assembled by single-crystal nanoflakes with nearly 97%exposed(100)facet,which maximizes the exposure of the feasible Li^(+)transport pathways along loosely packed 4g atomic layers to the electrolytes,thus effectively enhancing the Li^(+)-intercalation performance.Besides,the band gap of F-Nb_(2)O_(5) is reduced to 2.87 eV due to the doping of F atoms,leading to enhanced electrical conductivity.The synergetic effects between tailored exposed crystal facets,F-doping,and ultrathin building blocks,speed up the Li^(+)/electron transfer kinetics and improve the pseudocapacitive properties of F-Nb_(2)O_(5).Therefore,F-Nb_(2)O_(5) exhibit superior rate capability(210.8 and 164.9 mAh g^(-1) at 1 and 10 C,respectively)and good long-term 10 C cycling performance(132.7 mAh g^(-1) after 1500 cycles).展开更多
This study examines the relationship between job satisfaction and performance,investigating personality traits and satisfaction aspects among employees of a Federal Higher Education Institution.A questionnaire was adm...This study examines the relationship between job satisfaction and performance,investigating personality traits and satisfaction aspects among employees of a Federal Higher Education Institution.A questionnaire was administered to 658 participants,using structural equation modeling for analysis.Results highlighted that challenging work,neuroticism,and self-esteem significantly influenced overall workplace satisfaction,while general satisfaction,self-efficacy,and lack of attention were key determinants of work performance.This emphasizes the importance for managers to prioritize factors enhancing employee satisfaction,as it positively correlates with job performance.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21406164, 21466035 and 51203111)the National Basic Research Program of China ("973" Program, Nos. 2012CB720100 and 2014CB239300)
文摘Response surface methodology(RSM) was employed to optimize the control parameters of TiO_2/graphene with exposed {001} facets during synthesis, and its enhanced photocatalytic activities were evaluated in the photodegradation of toluene. Experimental results were in good agreement with the predicted results obtained using RSM with a correlation coefficient(R^2) of 0.9345. When 22.06 mg of graphite oxide(GO) and 2.09 mL of hydrofluoric acid(HF) were added and a hydrothermal time of 28 h was used, a maximum efficiency in the degradation of toluene was achieved. X-ray diffraction(XRD), transmission electron microscopy(TEM), and scanning electron microscopy(SEM) were employed to characterize the obtained hybrid photocatalyst. The electron transferred between Ti and C retarded the combination of electron–hole pairs and hastened the transferring of electrons, which enhanced the photocatalytic activity.
文摘The highly conserved abundant nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) is activated by DNA damage. PARP-1 activation is associated in DNA repair, cell death and inflammation. Since oxidative stress induced robust DNA damage and wide spread inflamma- tory responses are common pathologies of various CNS diseases, the attention towards PARP-1 as a therapeutic target has been amplifying. This review highlights the multiple roles of PARP- 1 in neurological diseases and po- tential of PARP- 1 inhibitors to enter clinical translation.
基金sponsored by National Social Science Foundation of China(Grant No. 11BTQ009)
文摘Purpose: This study aims to explore the relationships between different facets of work task and selection and query-related behavior.Design/methodology/approach:An experiment was conducted to explore the issue. The researcher recruited 24 participants and assigned six simulated work task situations to each of them. Each experiment lasted around 2 hours and was recorded by the software tool Morae.Findings: Time(frequency) and time(length) are more closely related to user’s selection and query-related behavior compared to the facet ‘process’ of work task. Knowledge level of work task topic, degree of work task difficulty, and subjective work task complexity are significantly correlated with selection and query-related behavior. Work task difficulty and work task complexity are different concepts. Subjective work task complexity, work task difficulty, and knowledge of work task topic are significantly correlated with user’s selection and query-related behavior.Research limitations/implications: The limitations of this study include a small sample size,limited work task situations, and possible spurious relationships. This study has implications in informing task-based information seeking/search/retrieval research and interactive information retrieval(IIR) systems design.Originality/values: Previous studies usually did not touch upon how different facets of work tasks affected interactive activities. Some studies examining task complexity and information behavior were concerned with how work tasks affect users’ behavior at information-seeking level, rather than at information search level. This study makes contribution to interactive information retrieval,task-based information search and retrieval, and personalization of IR.
基金the National Natural Science Foundation of China (U1632273, 21673214,U1732272, U1832165).
文摘This study investigated the positive effect of surface modification with ozone on the photocatalytic performance of anatase TiO2 with dominated (001) facets for toluene degradation. The performance of photocatalyst was tested on a home-made volatile organic compounds degradation system. The ozone modification, toluene adsorption and degradation mecha-nism were established by a combination of various characterization methods, in situ diuse reectance infrared fourier transform spectroscopy, and density functional theory calculation. The surface modtication with ozone can signiticantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5c-Ti sites on (001) facets act as the adsorption sites for ozone. The formed Ti-O bonds reacted with H2O to generate a large amount of isolated Ti5c-OH which act as the adsorption sites for toluene, and thus signi- cantly increase the adsorption capacity for toluene. The outstanding photo- catalytic performance of ozone-modified TiO2 is due to its high adsorption ability for toluene and the abundant surface hydroxyl groups, which produce very reactive OH· radicals under irradiation. Furthermore, the O2 generated via ozone dissociation could combine with the photogenerated electrons to form superoxide radicals which are also conductive to the toluene degradation.
基金supported by the National Natural Science Foundation of China(21307012)Educational Commission of Fujian Province(JK2013007,2014J01035,JA15138)
文摘S-doped Sb_2O_3 nanocrystals were synthesized using SbCl3 and thioacetamide(TAA) as starting materials by a hydrothermal method and the effects of TAA dosage on the composition and properties of resultant nanocrystals were determined.Their photocatalytic performance was evaluated using the degradation of methyl orange(MO) as a model reaction.The results suggest that TAA dosage can affect the preferential growth direction of Sb_2O_3,and further influences its photocatalytic activity.S doping can extend the optical absorption edge of Sb_2O_3 to the visible light religion,and thus endows its ability to photocatalyze the degradation of MO under visible light illumination.Based on these results,the correlations between the photocatalytic activity of S-doped Sb_2O_3 and the ratio between exposed facets,specific surface area and crystallographic defects were discussed.
文摘Let M be a matroid defined on a finite set E and L?⊂?E?. L is locked in M if??and ?are 2-connected, and . In this paper, we prove that the nontrivial facets of the bases polytope of M are described by the locked subsets. We deduce that finding the maximum-weight basis of M is a polynomial time problem for matroids with a polynomial number of locked subsets. This class of matroids is closed under 2-sums and contains the class of uniform matroids, the Vámos matroid and all the excluded minors of 2-sums of uniform matroids. We deduce also a matroid oracle for testing uniformity of matroids after one call of this oracle.
基金supported by the National Natural Science Foundation of China(41702037,41831285 and 41872039)Project of State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology(18fksy0216)。
文摘The manipulation of the surface property of WO_(3) photoanode is the main breakthrough direction to improve its solar water oxidation performance both in thermodynamics and kinetics.Here,we report a WO_(3)(002)/m-WO_(3) homojunction film that is composed of an upper WO_(3) layer with predominant(002)facet(WO_(3)(002))and a lower WO_(3) layer with multi-crystal facets(m-WO_(3))as a photoanode for solar water oxidation.Due to the synergistic effect of WO_(3)(002)layer and m-WO_(3) layer,better water oxidation activity and stability are achieved on the WO_(3)(002)/m-WO_(3) homojunction film relative to the m-WO_(3) and WO_(3)(002)film.Specifically,the improved water oxidation performance on the WO_(3)(002)/m-WO_(3) homojunction film is attributed to the followings.In thermodynamics,the band position differences between WO_(3)(002)layer and m-WO_(3) layer lead to the formation of WO_(3)(002)/m-WO_(3) homojunction,which has positive function of improving their charge separation and transfer.In kinetics,the upper WO_(3)(002)layer of the WO_(3)(002)/m-WO_(3) film has superior activity in the adsorption and activation of water molecules,water oxidation on this homojunction film photoanode is inclined to follow the four-holes pathway,and the corrosion of photoanode from the H_(2)O_(2) intermediate is restrained.The present work provides a new strategy to modify the WO_(3) photoanodes for thermodynamically and kinetically efficient water oxidation.
基金financially supported by the National Natural Science Foundation of China(52072165,51662031 and 51720105001)the general project of science and technology research of Jiangxi Provincial Department of Education(DA202102160)+1 种基金the project funded by China Postdoctoral Science Foundation(2019M653583)the starting research fund(EA202102179)。
文摘Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies of S atoms on different facets as well as the surface energies of Co_(2)P indicate that the HIFs become more stable after adsorbing S atoms.With rich unsaturated sites on HIFs,the photochemical reduction rate of CO_(2)over Co_(2)P NRs is 14.5 mmol h^(-1)g^(-1)for the production of CO within 3 h.The analysis of electron transfer,bond lengths,bond angles and adsorption energies indicate that the CO_(2)molecules are more easily adsorbed and activated on the HIFs.The free energy calculations and d band theory demonstrate that the HIFs are conducive to reducing the formation energy barriers as well as improving the stability of the intermediate^(*)COOH,then enhancing the catalytic performance of CO_(2)reduction.
文摘Non-carious cervical lesions (NCCLs) are defined as the loss of dental hard tissue at the cement-enamel junction. Erosion, abrasion, and attrition have been associated with this disorder. Objective: Recently, occlusal stress causing of cervical enamel cracks (abfraction) has been considered as an additional etiology for NCCLs to facilitate the erosion and abrasion mechanisms in tooth wear. Study Design: The prevalence of NNCLs and wear facets in a population with permanent dentition in absence of any clear etiological factors related to erosion and abrasion causes is evaluated. A total 295 subjects are enrolled for this study and divided into four age groups (subjects aged 15 - 27 years, 28 - 42 years, 43 - 57 years and 58 - 75 years respectively). An overall of 6629 teeth are investigated to find NCCLs and wear facets. The occlusion is analyzed in each patient. Results: An overall of 801 teeth (12%) show NCCLs and 623 of them (78%) highlight also wear facets. The higher number of teeth with NCCLs and of these with simultaneous presence also of wear facets are found on teeth of patients of group-3 (11% of all teeth examined for group and 81% respectively) and to group-4 (24.4% of all teeth examined for group and 86.5% respectively) of remaining teeth without NCCLs (5828) only 138 (2.4%) shown wear facets. Conclusion: The results of this study held the occlusal forces as the main cause of NCCLs on teeth in presence of wear facets.
基金supported by the National Natural Science Foundation of China(No.51972177)the Natural Science Foundation of Ningbo City(No.2021J067)the SJLY2021010 of Ningbo University,Fan 3315 Plan,and Yongjiang Scholar Project.
文摘Localized CdS homojunctions with optimal ratio of high and low index facets are constructed to dy-namically boost H_(2)O splitting into H_(2)energy by hydrothermal method in combination with calcination.By density functional theory,hall effect,and in situ diffuse reflectance infrared Fourier transform spec-troscopy,it is revealed that photo-irradiated e^(−)and h^(+)can be spatially separated and directionally trans-ferred to the reductive high-index facet{002}and oxidative low-index facet{110}of localized CdS homo-junction induced by Fermi level difference of both high and low index facets to dehydrogenate ^(∗)-OH and coupled ^(∗)-O intermediates for H_(2)and O_(2)yield,respectively,along with a solar conversion into hydrogen of 1.93%by AM 1.5 G irradiation at 65℃.The study work suggests a scientific perspective on the optimal ratio of high and low index facets to understand photo-generated charge carrier transfer dynamically and their photocatalytic principle for H_(2)O splitting reaction in kinetics.
基金supported by the National Natural Science Foundation of China(Grant Nos.52225606 and 51888103)the Fundamental Research Funds for the Central Universities,Chinathe Youth Innovation Team of Shaanxi Universities,China.
文摘It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,respectively.In such cases,only one family of facets can be used for photocatalytic hydrogen evolution.Herein,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all facets.The photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}facets.Thus,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.
基金financially supported by The National Key Research and Development Program of China(2021YFA1600800)the Start-up Funding of the Huazhong University of Science and Technology(HUST)+2 种基金the Program for HUST Academic Frontier Youth Teamthe National Natural Science Foundation of China(22075092)the National 1000 Young Talents Program of China and The Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)。
文摘Cu-based electrocatalysts with favorable facets and Cu^(+)can boost CO_(2) reduction to valuable multicarbon products.However,the inevitable Cu^(+)reduction and the phase evolution usually result in poor performance.Herein,we fabricate CuI nanodots with favorable(220)facets and a stable Cu^(+)state,accomplished by operando reconstruction of Cu(OH)_(2) under CO_(2)-and I--containing electrolytes for enhanced CO_(2)-to-C_(2)H_(4) conversion.Synchrotron X-ray absorption spectroscopy(XAS),in-situ Raman spectroscopy and thermodynamic potential analysis reveal the preferred formation of CuI.Vacuum gas electroresponse and density functional theory(DFT)calculations reveal that CO_(2)-related species induce the exposure of the(220)plane of Cu I.Moreover,the small size of nanodots enables the adequate contact with I^(-),which guarantees the rapid formation of Cu I instead of the electroreduction to Cu^(0).As a result,the resulting catalysts exhibit a high C2H4 Faradaic efficiency of 72.4%at a large current density of 800 m A cm^(-2) and robust stability for 12 h in a flow cell.Combined in-situ ATR-SEIRS spectroscopic characterizations and DFT calculations indicate that the(220)facets and stable Cu^(+) in CuI nanodots synergistically facilitate CO_(2)/*CO adsorption and*CO dimerization.
基金This program was financially supported by the National Key R&D Program of China(No.2020YFA0405800)the National Natural Science Foundation of China(NSFC)(Nos.U1932201,and 51902303)+2 种基金CAS International Partnership Program(No.211134KYSB20190063)China Postdoctoral Science Foundation(Nos.BX20200322,and 2020M682009)the Natural Science Foundation of Anhui Province(No.2108085QA31).
文摘To achieve a complete industrial chain of hydrogen energy,the development of efficient electrocatalysts for hydrogen evolution reaction(HER)is of great concerns.Herein,a nickel nitride supported platinum(Pt)catalyst with highly exposed Pt(110)facets(Pt_((110))-Ni_(3)N)is obtained for catalyzing HER.Combined X-ray spectra and density functional theory studies demonstrate that the interfacial electronic interaction between Pt and Ni3N support can promote the hydrogen evolution on Pt(110)facets by weakening hydrogen adsorption.As a result,the Pt_((110))-Ni_(3)N catalyst delivers an obviously higher specific activity than commercial 20 wt.%Pt/C in acidic media.This work suggests that the suitable interface modulation may play a vital role in rationally designing advanced electrocatalysts.
基金This work was supported by the National Natural Science Foundation of China(No.22102218)the Natural Science Foundation of Hunan Province(No.2020JJ4684)+1 种基金the science and technology innovation Program of Hunan Province(No.2022RC1110)the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University(No.CSUZC202221).
文摘The development of thermodynamically controllable synthetic strategy to manipulate the morphology of ZIF-8 without capping agent is essential to help understanding their facet effect and the structure-activity relationship of single atom catalysts derived from ZIF-8.Here,we prepared ZIF-8 with different morphologies(cube,truncated rhombododecahedral and rhombododecahedral)and thus area ratio of exposed{100},{110}facets by a thermodynamically controllable synthetic strategy.When the reaction proceeds under room temperature(30℃),the assembling of ZIF-8 followed an area-reducing layered growth mode,while switched to an integral layered growth mode at lower temperature-40℃.Moreover,this strategy also works to obtain ZIF-8 encapsulated with metal precursors(Fe(acac)_(3),Cu(acac)_(2)and Co(acac)_(2)).Single Fe atom anchored on nitrogen doped carbon catalysts(SA-Fe/CN)derived from Fe-ZIF-8 retain their original morphologies and the unsaturated surface-active sites on{100}facet,which further displays different catalytic performance towards oxygen reduction reaction(ORR).This work not only reveals the different growth pattern of ZIF-8,but also points out a new direction for designing and synthesizing MOFs with different morphology rationally.
基金This work was financially supported by the Natural Science Foundation of China(Nos.51832003 and 52003212)the Fun-damental Research Funds for the Central University(No.WUT 2020III034).
文摘Natural photosynthesis,which provides a green and high-efficiency energy conversion path by spatial separation of photogenerated carriers through combined actions of molecules ingeniously arranged in an efficient solar nanospace,highlights the importance of rational nanostructure design to realize artificial high-efficiency photosystem.Inspired by these unique features,we constructed a high-efficiency ternary photosystem by selectively decorating the{001}facets of 18-facet SrTiO_(3)with Au@CdS photosensitizers via a green photo-assisted method.Benefiting from the dual-facilitated charge carriers transportation in core-shell structured Au@CdS heterojunction and well-faceted 18-facet SrTiO_(3)nanocrystal,such a photo-catalyst could realize the effective spatial separation of photogenerated electrons and holes.As expected,the 18-facet SrTiO_(3)/Au@CdS photocatalyst exhibits superior activity in visible-light-driven photocatalytic hydrogen evolution(4.61 mmol h^(−1)g^(−1)),166%improvement in comparison with randomly deposited Au@CdS(1.73 mmol h^(−1)g^(−1)).This work offers new insight into the development of green and high-efficiency photocatalytic systems based on the rational nanostructure design by crystal facet engineering.
基金the NSF(CBET-2219546)and startup funds from the Georgia Institute of Technology.
文摘Noble-metal nanocrystals enclosed by high-index facets are of growing interest due to their enhanced catalytic performance in a variety of reactions.Herein,we report the deterministic synthesis of Pd nanocrystals encased by high-index facets by controlling the rate of deposition(V_(deposition))relative to that of surface diffusion(V_(diffusion)).For octahedral seeds with truncated corners,a reduction rate(and thus deposition rate)faster than that of surface diffusion(i.e.,V_(deposition)/V_(diffusion)>1)led to the formation of concave trisoctahedra(TOH)with high-index facets.When the reduction was slowed down,in contrast,surface diffusion dominated the growth pathway.In the case of V_(deposition)/V_(diffusion)≈1,truncated octahedra with enlarged sizes were produced.When the reduction rate was between these two extremes,we obtained concave tetrahexahedra(THH)without or with truncation.Similar growth patterns were also observed for the cuboctahedral seeds.When the Pd octahedra,concave TOH,and concave THH were tested for electrocatalyzing the formic acid oxidation(FAO)reaction,those with high-index facets were advantageous over the conventional Pd octahedra enclosed by{111}facets.This work not only contributes to the understanding of surface diffusion and its role in nanocrystal growth but also offers a general protocol for the synthesis of nanocrystals enclosed by high-index facets.
基金supported by the National Natural Science Foundation of China(No.51802163)the Natural Science Foundation of Henan Province of China(No.222300420252)the Natural Science Foundation of Henan Department of Education(No.20A480004).
文摘Orthorhombic Nb_(2)O_(5)(T-Nb_(2)O_(5))is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion storage.Herein,F-doped T-Nb_(2)O_(5) microflowers(F-Nb_(2)O_(5))are rationally synthesized through topotactic conversion.Specifically,F-Nb_(2)O_(5) are assembled by single-crystal nanoflakes with nearly 97%exposed(100)facet,which maximizes the exposure of the feasible Li^(+)transport pathways along loosely packed 4g atomic layers to the electrolytes,thus effectively enhancing the Li^(+)-intercalation performance.Besides,the band gap of F-Nb_(2)O_(5) is reduced to 2.87 eV due to the doping of F atoms,leading to enhanced electrical conductivity.The synergetic effects between tailored exposed crystal facets,F-doping,and ultrathin building blocks,speed up the Li^(+)/electron transfer kinetics and improve the pseudocapacitive properties of F-Nb_(2)O_(5).Therefore,F-Nb_(2)O_(5) exhibit superior rate capability(210.8 and 164.9 mAh g^(-1) at 1 and 10 C,respectively)and good long-term 10 C cycling performance(132.7 mAh g^(-1) after 1500 cycles).
文摘This study examines the relationship between job satisfaction and performance,investigating personality traits and satisfaction aspects among employees of a Federal Higher Education Institution.A questionnaire was administered to 658 participants,using structural equation modeling for analysis.Results highlighted that challenging work,neuroticism,and self-esteem significantly influenced overall workplace satisfaction,while general satisfaction,self-efficacy,and lack of attention were key determinants of work performance.This emphasizes the importance for managers to prioritize factors enhancing employee satisfaction,as it positively correlates with job performance.