With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is th...With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is that the size and shape of ZnS nanocrystals can be tuned by adjusting the surfactant and its feed. The UV-Vis absorption spectra of quasispherical and one-dimensional quantum-sized ZnS nanocrystals all showed a blue-shift from the bulk counterpart, indicating large quantum confinement effects of ZnS nanocrystals. These ZnS nanocrystals all showed well-defined excitonic emission features. Contrastive studies on photoluminescence performances indicated that the bandedge emission experienced only the size-dependent quantum confinement effect, while the trap-state emission experienced the size- and shape-dependences. So we can design a purposeful synthesis route to ZnS nanocrystals with target luminescence emission performances.展开更多
Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a stra...Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great challenge.Herein,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical method.Benefiting from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like BiOBr.The photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.展开更多
The ordered membrane electrode assembly(MEA)has gained much attention because of its potential in improving mass transfer.Here,a comprehensive study was conducted on the influence of the patterned microporous layer(MP...The ordered membrane electrode assembly(MEA)has gained much attention because of its potential in improving mass transfer.Here,a comprehensive study was conducted on the influence of the patterned microporous layer(MPL)on the proton exchange membrane fuel cell performances.When patterned MPL is employed,grooves are generated between the catalyst layer and the gas diffusion layer.It is found that the grooves do not increase the contact resistance,and it is beneficial for water retention.When the MEA works under low humidity scenarios,the MEA with patterned MPL illustrated higher performance,due to the reduced inner resistance caused by improved water retention,leading to increased ionic conductivity.However,when the humidity is higher than 80%or working under high current density,the generated water accumulated in the grooves and hindered the oxygen mass transport,leading to a reduced MEA performance.展开更多
In this study,we aimed to explore the safety and vaccination coverage data of Chinese patients with breast cancer receiving coronavirus disease 2019(COVID-19)vaccination.The patients were recruited from 41 hospitals a...In this study,we aimed to explore the safety and vaccination coverage data of Chinese patients with breast cancer receiving coronavirus disease 2019(COVID-19)vaccination.The patients were recruited from 41 hospitals across 20 Chinese provinces.The vaccination coverage was approximately 22.4%,and the frequency of total adverse events was 13.3%after the first dose and 9.9%after the second dose.The most frequent adverse reaction within 14 days of the first dose was local pain(5.7%).Unvaccinated patients were very likely to reject the vaccine rather than be hesitant in patients with old age(odds ratio[OR],1.238;95%confidence interval[CI],1.101-1.391),chronic disease history(OR,1.189;95%CI,1.057-1.337),and cancer relapse(OR,1.398;95%CI,1.233-1.585).Of the unvaccinated patients with breast cancer,54.1%opted to receive COVID-19 vaccines if more data were available.Considering the safety but low vaccination coverage for breast cancer,increased positive attitudes and acceptance toward COVID-19 vaccines are important.展开更多
文摘With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is that the size and shape of ZnS nanocrystals can be tuned by adjusting the surfactant and its feed. The UV-Vis absorption spectra of quasispherical and one-dimensional quantum-sized ZnS nanocrystals all showed a blue-shift from the bulk counterpart, indicating large quantum confinement effects of ZnS nanocrystals. These ZnS nanocrystals all showed well-defined excitonic emission features. Contrastive studies on photoluminescence performances indicated that the bandedge emission experienced only the size-dependent quantum confinement effect, while the trap-state emission experienced the size- and shape-dependences. So we can design a purposeful synthesis route to ZnS nanocrystals with target luminescence emission performances.
基金supported by the National Natural Science Foundation of China(No.52162023)the Natural Science Foundation of Xinjiang Autonomous Region(No.2021D01C093)+1 种基金the Xinjiang Tianchi Doctoral Project(No.TCBS201933)the Xinjiang University Doctoral Research Foundation(No.BS190228).
文摘Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great challenge.Herein,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical method.Benefiting from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like BiOBr.The photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.
基金supported by Beijing Natural Science Foundation(No.Z210016).
文摘The ordered membrane electrode assembly(MEA)has gained much attention because of its potential in improving mass transfer.Here,a comprehensive study was conducted on the influence of the patterned microporous layer(MPL)on the proton exchange membrane fuel cell performances.When patterned MPL is employed,grooves are generated between the catalyst layer and the gas diffusion layer.It is found that the grooves do not increase the contact resistance,and it is beneficial for water retention.When the MEA works under low humidity scenarios,the MEA with patterned MPL illustrated higher performance,due to the reduced inner resistance caused by improved water retention,leading to increased ionic conductivity.However,when the humidity is higher than 80%or working under high current density,the generated water accumulated in the grooves and hindered the oxygen mass transport,leading to a reduced MEA performance.
基金Emergency Key Program of Guangzhou Laboratory(EKPG21-30-4)。
文摘In this study,we aimed to explore the safety and vaccination coverage data of Chinese patients with breast cancer receiving coronavirus disease 2019(COVID-19)vaccination.The patients were recruited from 41 hospitals across 20 Chinese provinces.The vaccination coverage was approximately 22.4%,and the frequency of total adverse events was 13.3%after the first dose and 9.9%after the second dose.The most frequent adverse reaction within 14 days of the first dose was local pain(5.7%).Unvaccinated patients were very likely to reject the vaccine rather than be hesitant in patients with old age(odds ratio[OR],1.238;95%confidence interval[CI],1.101-1.391),chronic disease history(OR,1.189;95%CI,1.057-1.337),and cancer relapse(OR,1.398;95%CI,1.233-1.585).Of the unvaccinated patients with breast cancer,54.1%opted to receive COVID-19 vaccines if more data were available.Considering the safety but low vaccination coverage for breast cancer,increased positive attitudes and acceptance toward COVID-19 vaccines are important.
