The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been d...The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been discussed.Here we give a proof-of-concept illustration on the intrinsic facets effect by employing the popularly investigated NH2-MIL-125(Ti)MOFs with{001},{111}and{100}facets controllably exposed as model photocatalysts,which were synthesized via a simple supersaturation strategy free of any capping agents.Compared to conventional synthetic routes with capping agents employed,the NH2-MIL-125(Ti)MOFs obtained in this work exhibit remarkably different physical and chemical properties such as surface wettability,charge separation as well as trend of facets effect on photocatalytic water splitting performance.The main reason has been unraveled to originate from unavoidable residue/influence of capping agents during the conventional facets-controlled synthetic routes leading to changed local surface structural environment as well as distinct charge separation property.Our results demonstrate the importance and feasibility of facets-controllable synthesis free of capping agents in getting insight into the intrinsic facets effect of MOFs-related materials.展开更多
The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notab...The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal type.Nevertheless,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage conditions.This study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO CAMs.By tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal facets.The(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)facets.Our study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.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
Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be exte...Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.展开更多
Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particle...Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particles are found to be greatly dependent on the ratio of H_(2)O_(2)-NH_(3) solution.The prepared TiO_(2) particles with specific exposed crystal faces show higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO_(2) particles.This result implies that recombination is prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face.展开更多
A sample of sulfated anatase TiO2 with high‐energy(001)facets(TiO2‐001)was prepared by a simple one‐step hydrothermal route using SO42-as a morphology‐controlling agent.After doping ceria,Ce/TiO2‐001 was used as ...A sample of sulfated anatase TiO2 with high‐energy(001)facets(TiO2‐001)was prepared by a simple one‐step hydrothermal route using SO42-as a morphology‐controlling agent.After doping ceria,Ce/TiO2‐001 was used as the catalyst for selective catalytic reduction(SCR)of NO with NH3.Compared with Ce/P25(Degussa P25 TiO2)and Ce/P25‐S(sulfated P25)catalysts,Ce/TiO2‐001 was more suitable for medium‐and high‐temperature SCR of NO due to the high surface area,sulfation,and the excellent properties of the active‐energy(001)facets.All of these facilitated the generation of abundant acidity,chemisorbed oxygen,and activated NOx‐adsorption species,which were the important factors for the SCR reaction.展开更多
The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excelle...The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties.In this paper,TiO_(2) nanoplates with defective{001}facets were synthesized by chemical etching via one-step hydrothermal method.We carefully explored the gas-sensing performance of TiO_(2) nanoplates with defective and complete{001}facets towards acetone.The results show that the sensing response of TiO_(2) nanoplates with complete{001}facets is 70%higher than that of defective TiO_(2) nanoplates,which proves that the{001}facets plays a vital role in improving the gas sensing performance of TiO_(2).It is speculated that the poor gas sensitivity of defective TiO_(2) can be contributed to fewer adsorption sites and blocked electron transfer.This work presents a more direct evidence for explaining the important role of the complete{001}crystal facets in high sensitivity of TiO_(2) and also provides a new insight for preparing high sensitivity sensing materials.展开更多
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 photodegra...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
Nitrogen(N)and phosphorus(P)co-doped anatase TiO_(2) nanosheets were realized by low-temperature self-doping N-TiO_(2) followed by high-temperature P doping with foreign precursor.It is found that P doping process can...Nitrogen(N)and phosphorus(P)co-doped anatase TiO_(2) nanosheets were realized by low-temperature self-doping N-TiO_(2) followed by high-temperature P doping with foreign precursor.It is found that P doping process can maintain good TiO_(2) nanosheets morphology with exposed{001}facets.Chemical state of dopants indicates that N and P atoms replace O on O sites in TiO_(2) lattice.Compared with pure TiO_(2) and N-doped TiO_(2),N-P codoped TiO_(2) nanosheets exhibits stronger optical absorption and higher degradation rate of dye molecules in visible light regime.The enhanced photocatalytic properties are attributed to two factors.On one hand,N-P co-doping can effectively reduce band gap of TiO_(2) from 3.20 to 2.48 eV,leading to an enhancement of the absorption in visible light regime.On the other hand,the presence of exposed{001}facets of TiO_(2) nanosheets can induce the effective sepa-ration of photogenerated electrons and holes in reaction.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
Radiotherapy is one of the most important clinical cancer treatments,which works mainly by delive ring a prescribed radiation dose to the tumor tissues.However,high doses of radiation may also lead many irreversible d...Radiotherapy is one of the most important clinical cancer treatments,which works mainly by delive ring a prescribed radiation dose to the tumor tissues.However,high doses of radiation may also lead many irreversible damages to the surrounding normal tissues.Thereby,how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect.In this work,we synthesized the hollow PtPd nanocubes with high-index facets,and investigated the radiation protection capability in vitro and in vivo.Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells.Meanwhile,survival rate of radiated mice can significantly increase from 0 to 30%after PtPd treatment.Consequently,the enzyme and ROS level in radiated mice can be recovered.展开更多
Understanding and establishing the structure-activity relation of nanoparticles is a prerequisite for rational design of high-performance electrocatalysts.Cu_(2)O nanoparticles enclosed with different crystal facets,n...Understanding and establishing the structure-activity relation of nanoparticles is a prerequisite for rational design of high-performance electrocatalysts.Cu_(2)O nanoparticles enclosed with different crystal facets,namely,o-Cu_(2)O NPs with{111}facets,c-Cu_(2)O NPs with{100}facets are prepared and their electrocatalytic properties for oxygen evolution reaction(OER)in alkaline condition are evaluated at single nanoparticle level with a combination of scanning electrochemical cell microscopy and scanning electron microscopy.It is found that the o-Cu_(2)O NPs have significantly superior OER electrocatalytic activity compared to c-Cu_(2)O,which is almost inert.The estimated turnover frequency(TOF)at 1.97 V vs.RHE on{111}facet increases from 4 s^(-1) to 115 s^(-1) with the octahedron edge length decreasing from 1.3μm to 100 nm.Deposition of carbon on c-Cu_(2)O surface barely promotes the activity,suggesting the inherent poor electric conductivity within the nanocrystal is most likely the reason for low activity.This work provides direct probing to single transition metal oxide crystals with dramatically different activity.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 mechanism were established by a combination of various characterization methods, in situ diffuse reflectance infrared fourier transform spectroscopy, and density functional theory calculation.The surface modification with ozone can significantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5 c-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 Ti5 c-OH which act as the adsorption sites for toluene,and thus significantly increase the adsorption capacity for toluene. The outstanding photocatalytic 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
Anatase phase visible-light-driven TiO_(2) yolk-shell spheres with the size of ca.1-2 um have been synthesized with the combination of solvothermal and heat treatment method.XRD,SEM,TEM,XPS,and PL analysis were used t...Anatase phase visible-light-driven TiO_(2) yolk-shell spheres with the size of ca.1-2 um have been synthesized with the combination of solvothermal and heat treatment method.XRD,SEM,TEM,XPS,and PL analysis were used to examine structure and properties of the photocatalyst.The N species and Ti3+centers introduced into the as-prepared photocatalyst can enhance the visible light absorption significantly.The mesoporous shell of the prepared photocatalyst,which promotes the pollutant adsorption ability,consists of the high-reactive[001]facets dominated nanocrystals.Due to the unique structure,it is also observed that the as-prepared visible-light-driven TiO_(2) yolk-shell spheres exhibit a sunerinr nhnrncatalvtic activity for organic dyes decomposition than the well-known P25.展开更多
文摘The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been discussed.Here we give a proof-of-concept illustration on the intrinsic facets effect by employing the popularly investigated NH2-MIL-125(Ti)MOFs with{001},{111}and{100}facets controllably exposed as model photocatalysts,which were synthesized via a simple supersaturation strategy free of any capping agents.Compared to conventional synthetic routes with capping agents employed,the NH2-MIL-125(Ti)MOFs obtained in this work exhibit remarkably different physical and chemical properties such as surface wettability,charge separation as well as trend of facets effect on photocatalytic water splitting performance.The main reason has been unraveled to originate from unavoidable residue/influence of capping agents during the conventional facets-controlled synthetic routes leading to changed local surface structural environment as well as distinct charge separation property.Our results demonstrate the importance and feasibility of facets-controllable synthesis free of capping agents in getting insight into the intrinsic facets effect of MOFs-related materials.
基金supported by the National Natural Science Foundation of China (52374311)the National Natural Science Foundation of Shaanxi (2022KXJ-146)+3 种基金the Fundamental Research Funds for the Central Universities (D5000230091)Open project of Shaanxi Laboratory of Aerospace Power (2022ZY2-JCYJ-01-09)full-depth-sea battery project (No.2020-XXXX-XX-246-00)the Youth Innovation Team of Shaanxi Universities。
文摘The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal type.Nevertheless,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage conditions.This study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO CAMs.By tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal facets.The(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)facets.Our study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.
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.
文摘Ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets have attracted considerable attention because of their high photocatalytic activity.However,the charge-separated states in the TiO_(2)nanosheets must be extended to further enhance their photocatalytic activity for H_(2)evolution.Herein,we present a successful attempt to selectively dope lanthanide ions into the{101}facets of ultrathin TiO_(2)nanosheets with coexposed{001}/{101}facets through a facile one-step solvothermal method.The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO_(2)nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra.Upon simulated sunlight irradiation,we observed a 4.2-fold enhancement in the photocatalytic H_(2)evolution activity of optimal Yb^(3+)-doped TiO_(2)nanosheets compared to that of their undoped counterparts.Furthermore,when Pt nanoparticles were used as cocatalysts to reduce the H_(2)overpotential in this system,the photocatalytic activity enhancement factor increased to 8.5.By combining these results with those of control experiments,we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H_(2)evolution activity of lanthanide-doped TiO_(2)nanosheets with coexposed{001}/{101}facets.
基金financially supported by the Programs of Japan Science and Technology Agency:Promoting Individual Research to Nature the Seeds of Future Innovation and Organizing the Unique and Innovative Network,and Advanced Catalytic Transformation Program for Carbon Utilization
文摘Anatase titanium(IV)oxide(TiO_(2))particles with exposed{001}and{101}facets were prepared by hydrothermal treatment of amorphous TiO_(2) with H_(2)O_(2)-NH_(3) solution.Crystal phase,shape,and size of TiO_(2) particles are found to be greatly dependent on the ratio of H_(2)O_(2)-NH_(3) solution.The prepared TiO_(2) particles with specific exposed crystal faces show higher photocatalytic activity for acetaldehyde decomposition than commercial spherical TiO_(2) particles.This result implies that recombination is prevented by spatial separation of redox sites in the particles because of selective migration of electrons and positive holes to specific exposed crystal faces and/or different reactivity of electrons and positive holes on the specific exposed crystal face.
基金supported by the National Key R&D Program of China(2016YFC0204100)the Zhejiang Provincial "151" Talents Program+1 种基金the Program for Zhejiang Leading Team of S&T Innovation(2013TD07)the Changjiang Scholar Incentive Program(2009)~~
文摘A sample of sulfated anatase TiO2 with high‐energy(001)facets(TiO2‐001)was prepared by a simple one‐step hydrothermal route using SO42-as a morphology‐controlling agent.After doping ceria,Ce/TiO2‐001 was used as the catalyst for selective catalytic reduction(SCR)of NO with NH3.Compared with Ce/P25(Degussa P25 TiO2)and Ce/P25‐S(sulfated P25)catalysts,Ce/TiO2‐001 was more suitable for medium‐and high‐temperature SCR of NO due to the high surface area,sulfation,and the excellent properties of the active‐energy(001)facets.All of these facilitated the generation of abundant acidity,chemisorbed oxygen,and activated NOx‐adsorption species,which were the important factors for the SCR reaction.
基金financially supported by the National Natural Science Foundation of China(Nos.51773226,61701514)the Natural Science Foundation of Hunan Province(No.2018JJ3603)
文摘The exposed crystal facet of TiO_(2) is a crucial factor influencing the gas sensing properties.TiO_(2) with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties.In this paper,TiO_(2) nanoplates with defective{001}facets were synthesized by chemical etching via one-step hydrothermal method.We carefully explored the gas-sensing performance of TiO_(2) nanoplates with defective and complete{001}facets towards acetone.The results show that the sensing response of TiO_(2) nanoplates with complete{001}facets is 70%higher than that of defective TiO_(2) nanoplates,which proves that the{001}facets plays a vital role in improving the gas sensing performance of TiO_(2).It is speculated that the poor gas sensitivity of defective TiO_(2) can be contributed to fewer adsorption sites and blocked electron transfer.This work presents a more direct evidence for explaining the important role of the complete{001}crystal facets in high sensitivity of TiO_(2) and also provides a new insight for preparing high sensitivity sensing materials.
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financially supported by the National Natural Science Foundation of China(Nos.61434002,51571135)National Science Foundation of United States(Nos.DMR-1104994,CBET-1510121)+2 种基金Shanxi Scholars Program(No.[2012]12)"One Hundred Talented People"of Shanxi ProvinceShanxi Province Foundations(Nos.[2012]10,[2013]9)
文摘Nitrogen(N)and phosphorus(P)co-doped anatase TiO_(2) nanosheets were realized by low-temperature self-doping N-TiO_(2) followed by high-temperature P doping with foreign precursor.It is found that P doping process can maintain good TiO_(2) nanosheets morphology with exposed{001}facets.Chemical state of dopants indicates that N and P atoms replace O on O sites in TiO_(2) lattice.Compared with pure TiO_(2) and N-doped TiO_(2),N-P codoped TiO_(2) nanosheets exhibits stronger optical absorption and higher degradation rate of dye molecules in visible light regime.The enhanced photocatalytic properties are attributed to two factors.On one hand,N-P co-doping can effectively reduce band gap of TiO_(2) from 3.20 to 2.48 eV,leading to an enhancement of the absorption in visible light regime.On the other hand,the presence of exposed{001}facets of TiO_(2) nanosheets can induce the effective sepa-ration of photogenerated electrons and holes in reaction.
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supported by the National Natural Science Foundation of China (Nos.81673106,81471786 and 91859101)CAMS Innovation Fund for Medical Science (No.2017-12M-1012)
文摘Radiotherapy is one of the most important clinical cancer treatments,which works mainly by delive ring a prescribed radiation dose to the tumor tissues.However,high doses of radiation may also lead many irreversible damages to the surrounding normal tissues.Thereby,how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect.In this work,we synthesized the hollow PtPd nanocubes with high-index facets,and investigated the radiation protection capability in vitro and in vivo.Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells.Meanwhile,survival rate of radiated mice can significantly increase from 0 to 30%after PtPd treatment.Consequently,the enzyme and ROS level in radiated mice can be recovered.
基金the Fundamental Research Funds for the Central Universities(Nos.2232020A-09,2232021G-04)Natural Science Foundation of Shanghai(No.19ZR1470800)+1 种基金National Natural Science Foundation of China(No.21804018)Opening Project of PCOSS from Xiamen University(No.201906)for financial support.
文摘Understanding and establishing the structure-activity relation of nanoparticles is a prerequisite for rational design of high-performance electrocatalysts.Cu_(2)O nanoparticles enclosed with different crystal facets,namely,o-Cu_(2)O NPs with{111}facets,c-Cu_(2)O NPs with{100}facets are prepared and their electrocatalytic properties for oxygen evolution reaction(OER)in alkaline condition are evaluated at single nanoparticle level with a combination of scanning electrochemical cell microscopy and scanning electron microscopy.It is found that the o-Cu_(2)O NPs have significantly superior OER electrocatalytic activity compared to c-Cu_(2)O,which is almost inert.The estimated turnover frequency(TOF)at 1.97 V vs.RHE on{111}facet increases from 4 s^(-1) to 115 s^(-1) with the octahedron edge length decreasing from 1.3μm to 100 nm.Deposition of carbon on c-Cu_(2)O surface barely promotes the activity,suggesting the inherent poor electric conductivity within the nanocrystal is most likely the reason for low activity.This work provides direct probing to single transition metal oxide crystals with dramatically different activity.
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 mechanism were established by a combination of various characterization methods, in situ diffuse reflectance infrared fourier transform spectroscopy, and density functional theory calculation.The surface modification with ozone can significantly enhance the photocatalytic degradation performance for toluene. The abundant unsaturated coordinated 5 c-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 Ti5 c-OH which act as the adsorption sites for toluene,and thus significantly increase the adsorption capacity for toluene. The outstanding photocatalytic 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.
文摘Anatase phase visible-light-driven TiO_(2) yolk-shell spheres with the size of ca.1-2 um have been synthesized with the combination of solvothermal and heat treatment method.XRD,SEM,TEM,XPS,and PL analysis were used to examine structure and properties of the photocatalyst.The N species and Ti3+centers introduced into the as-prepared photocatalyst can enhance the visible light absorption significantly.The mesoporous shell of the prepared photocatalyst,which promotes the pollutant adsorption ability,consists of the high-reactive[001]facets dominated nanocrystals.Due to the unique structure,it is also observed that the as-prepared visible-light-driven TiO_(2) yolk-shell spheres exhibit a sunerinr nhnrncatalvtic activity for organic dyes decomposition than the well-known P25.
