A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,10...A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,100,150,200)Z-scheme heterojunctions toward the hexavalent chromium(Cr(VI))reduction and UAC-100 toward oxidative degradation of four organic dyes like rhodamine B(RhB),methyl orange(MO),congo red(CR),and methylene blue(MB)under visible light irradiation were investigated.The effects of different pH(pH=2,3,4,6,8),small organic acids(citric acid,tartaric acid,and oxalic acid),and foreign ions(ions in tap water and surface water)on Cr(VI)reduction were explored.The results revealed that the UAC-100 heterojunctions displayed more remarkable Cr(VI)reduction performance than the pristine UiO-66-NH2 and Ag2CO3,resulting from the improved separation of photo-induced electrons and holes.The enhanced photocatalytic activity of UAC-100 was further confirmed by the photoluminescence measurement,electrochemical analysis,and active species trapping experiments.After four cycles’experiments,the photocatalytic Cr(VI)reduction efficiency over UAC-100 was still over 99%,which exhibited that UAC-100 had excellent reusability and stability.Finally,the corresponding photocatalytic reaction mechanism was proposed and tested.展开更多
Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation...Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation.In this work,a metal free heterostructure of covalent triazine framework(CTF)and graphite carbon nitride(g‐C_(3)N_(4),abbreviated as CN)is applied in the CO_(2)photoreduction for the first time.Detailed characterization methods such as photoluminescence(PL)and time‐resolved PL(TR‐PL)decay are utilized to reveal the photo‐induced carries separating process on g‐C_(3)N_(4)/CTF(CN/CTF)heterostructure.The introduced CTF demonstrated a great boosting photocatalytic activity for CN,bringing about the transform rates of CO_(2)to CO reaching 151.1μmol/(g·h)with a 30 h stabilization time,while negligible CH_(4)was detected.The optimal CN/CTF heterostructure could more efficiently separate charges with a lower probability of recombination under visible light irradiation,which made the photoreduction efficiency of CO_(2)to CO be 25.5 and 2.5 times higher than that of CTF and CN,respectively.This investigation is expected to offer a new thought for fabricating high‐efficiency photocatalyst without metal in solar‐energy‐driven CO_(2)reduction.展开更多
Using Cu-BTC prepared by hydrothermal method as precursor, carbon-based catalysts were obtained as model materials for low-temperature DeNO_x. These catalysts were characterized by X-ray diffractometry（XRD）, Raman s...Using Cu-BTC prepared by hydrothermal method as precursor, carbon-based catalysts were obtained as model materials for low-temperature DeNO_x. These catalysts were characterized by X-ray diffractometry（XRD）, Raman spectroscopy, scanning electron microscopy（SEM） and energy dispersive X-ray spectrometry（EDS）. The results showed that all carbon-based catalysts held the octahedron shape of Cu-BTC in most parts, and they mainly consisted of face-centered cubic copper. CuO_x/C exhibited excellent catalytic activity, and such catalytic activity was further improved with the introduction of Ag. The catalyst with a Cu to Ag mole ratio of 6：1 and an activated temperature of 600 °C showed the best catalytic performance, and its catalytic denitration rate reached 100% at a temperature as low as 235 °C. During the catalytic reaction process, Cu~＋ mainly played a catalytic role.展开更多
AIM： To study the inhibitory effect of mononuclear bone marrow cell （BNC） transplantation on carbon tetrachloride （CCl4） -induced liver fibrosis in rats. METHODS： Rat liver fibrosis models were induced by CCl4 a...AIM： To study the inhibitory effect of mononuclear bone marrow cell （BNC） transplantation on carbon tetrachloride （CCl4） -induced liver fibrosis in rats. METHODS： Rat liver fibrosis models were induced by CCl4 and alcohol administration. After 8 wk, twenty rats were randomly allocated into treatment group （n = 10） and control group （n = 10）. BMC were infused into the rats in treatment group via the portal vein, while heparinized saline was infused in control group. CCl4 was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12, all rats were humanely sacrificed. Uver samples were taken and stained with HE or Masson trichrome. The general conditions, liver fibrosis （hydroxyproline and collagen fibre） and liver pathological grades in rats were evaluated. RESULTS： The general conditions of the rats in treatment group improved markedly, but not in control group. Hydroxyproline was 504.6± 128.8 μg/g in treatment group, and 596.0 ± 341.8 μg/g in control group. The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group. There was a significant difference between the two groups （P 〈 0.05）. Liver pathological grade decreased from grade N to grade 11 partially in treatment group （P 〈 0.05） with no obvious improvement in control group （P 〉 0.05）. There was a significant difference between treatment group and control group （P 〈 0.05）.CONCLUSION： Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.展开更多
文摘为提高α-磷酸三钙(-αTCP)骨水泥的强度及降低其脆性,将表面改性后的碳纤维(CF)与α-TCP粉复合,制备成-αTCP/CF复合增强骨水泥。通过R inger's体液浸泡观察骨水泥快速结晶自固化能力,运用扫描电子显微镜(SEM)及抗压强度测试仪对复合材料浸泡后试样进行断面显微结构分析及抗压强度测试。结果显示,α-TCP骨水泥块浸泡5 d后即转化生成片状羟基磷灰石晶体;适量的碳纤维在骨水泥基体中分布均匀,与基体结合性好,可得到抗压强度增强的骨修复材料;当碳纤维的加入重量百分数为0.5%时,复合材料抗压强度达到46.7 M Pa,比未增强的-αTCP材料提高了22%。
基金supported by the National Natural Science Foundation of China(51878023,51578034)Great Wall Scholars Training Program Project of Beijing Municipality Universities(CIT&TCD20180323)+2 种基金Project of Construction of Innovation Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(IDHT20170508)Beijing Talent Project(2018A35)BUCEA Post Graduate Innovation Project(PG2019039)~~
文摘A series of UiO-66-NH2/Ag2CO3 Z-scheme heterojunctions were prepared by a simple ion-exchange-solution method using UiO-66-NH2 and semiconductor Ag2CO3 as precursors.The photocatalytic activities of UAC-X(UAC-20,50,100,150,200)Z-scheme heterojunctions toward the hexavalent chromium(Cr(VI))reduction and UAC-100 toward oxidative degradation of four organic dyes like rhodamine B(RhB),methyl orange(MO),congo red(CR),and methylene blue(MB)under visible light irradiation were investigated.The effects of different pH(pH=2,3,4,6,8),small organic acids(citric acid,tartaric acid,and oxalic acid),and foreign ions(ions in tap water and surface water)on Cr(VI)reduction were explored.The results revealed that the UAC-100 heterojunctions displayed more remarkable Cr(VI)reduction performance than the pristine UiO-66-NH2 and Ag2CO3,resulting from the improved separation of photo-induced electrons and holes.The enhanced photocatalytic activity of UAC-100 was further confirmed by the photoluminescence measurement,electrochemical analysis,and active species trapping experiments.After four cycles’experiments,the photocatalytic Cr(VI)reduction efficiency over UAC-100 was still over 99%,which exhibited that UAC-100 had excellent reusability and stability.Finally,the corresponding photocatalytic reaction mechanism was proposed and tested.
文摘Solar‐driven CO_(2)conversion to precious fossil fuels has been proved to become a potential way to decrease CO_(2)with producing renewable fuels,which mainly relies on photocatalysts with efficient charge separation.In this work,a metal free heterostructure of covalent triazine framework(CTF)and graphite carbon nitride(g‐C_(3)N_(4),abbreviated as CN)is applied in the CO_(2)photoreduction for the first time.Detailed characterization methods such as photoluminescence(PL)and time‐resolved PL(TR‐PL)decay are utilized to reveal the photo‐induced carries separating process on g‐C_(3)N_(4)/CTF(CN/CTF)heterostructure.The introduced CTF demonstrated a great boosting photocatalytic activity for CN,bringing about the transform rates of CO_(2)to CO reaching 151.1μmol/(g·h)with a 30 h stabilization time,while negligible CH_(4)was detected.The optimal CN/CTF heterostructure could more efficiently separate charges with a lower probability of recombination under visible light irradiation,which made the photoreduction efficiency of CO_(2)to CO be 25.5 and 2.5 times higher than that of CTF and CN,respectively.This investigation is expected to offer a new thought for fabricating high‐efficiency photocatalyst without metal in solar‐energy‐driven CO_(2)reduction.
基金Project(738010004)supported by the Project of Low Concentration Sulfur Dioxide Flue Gas Treatment,ChinaProject(2017GK4010)supported by the Scientific and Technological Breakthrough and Major Achievements Transformation of Strategic Emerging Industries of Hunan Province in 2017,China
文摘Using Cu-BTC prepared by hydrothermal method as precursor, carbon-based catalysts were obtained as model materials for low-temperature DeNO_x. These catalysts were characterized by X-ray diffractometry（XRD）, Raman spectroscopy, scanning electron microscopy（SEM） and energy dispersive X-ray spectrometry（EDS）. The results showed that all carbon-based catalysts held the octahedron shape of Cu-BTC in most parts, and they mainly consisted of face-centered cubic copper. CuO_x/C exhibited excellent catalytic activity, and such catalytic activity was further improved with the introduction of Ag. The catalyst with a Cu to Ag mole ratio of 6：1 and an activated temperature of 600 °C showed the best catalytic performance, and its catalytic denitration rate reached 100% at a temperature as low as 235 °C. During the catalytic reaction process, Cu~＋ mainly played a catalytic role.
基金the Key Scientific and Technological Projects of Guangdong Province, No. 2005A30201007Guangdong Provincial Natural Science Fundation, No. 06021343
文摘AIM： To study the inhibitory effect of mononuclear bone marrow cell （BNC） transplantation on carbon tetrachloride （CCl4） -induced liver fibrosis in rats. METHODS： Rat liver fibrosis models were induced by CCl4 and alcohol administration. After 8 wk, twenty rats were randomly allocated into treatment group （n = 10） and control group （n = 10）. BMC were infused into the rats in treatment group via the portal vein, while heparinized saline was infused in control group. CCl4 was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12, all rats were humanely sacrificed. Uver samples were taken and stained with HE or Masson trichrome. The general conditions, liver fibrosis （hydroxyproline and collagen fibre） and liver pathological grades in rats were evaluated. RESULTS： The general conditions of the rats in treatment group improved markedly, but not in control group. Hydroxyproline was 504.6± 128.8 μg/g in treatment group, and 596.0 ± 341.8 μg/g in control group. The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group. There was a significant difference between the two groups （P 〈 0.05）. Liver pathological grade decreased from grade N to grade 11 partially in treatment group （P 〈 0.05） with no obvious improvement in control group （P 〉 0.05）. There was a significant difference between treatment group and control group （P 〈 0.05）.CONCLUSION： Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.
