A novel magnetically recoverable thioporphyrazine catalyst（CoPz（S-Bu）8/SiO2@Fe3O4） was prepared by immobilization of the cobalt octkis（butylthio） porphyrazine complex（CoPz（S-Bu）8） on silica-coated magnetic n...A novel magnetically recoverable thioporphyrazine catalyst（CoPz（S-Bu）8/SiO2@Fe3O4） was prepared by immobilization of the cobalt octkis（butylthio） porphyrazine complex（CoPz（S-Bu）8） on silica-coated magnetic nanospheres（SiO2@Fe3O4）. The composite CoPz（S-Bu）8/SiO2@Fe3O4appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide（H2O2） as oxidant under Xe-lamp irradiation,with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number（TON） of 61.7 at ambient temperature. The biomimetic catalyst CoPz（S-Bu）8was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz（S-Bu）8can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications.展开更多
Can the“Roof of the world”Mount Qomolangma(MQ)serve as a“natural laboratory”for the activation effect of aerosols on the cloud-precipitation process?Here,we carried out the vertical observations of aerosols,clouds...Can the“Roof of the world”Mount Qomolangma(MQ)serve as a“natural laboratory”for the activation effect of aerosols on the cloud-precipitation process?Here,we carried out the vertical observations of aerosols,clouds,and precipitation at the MQ,where the dual-radar active remote sensing technique is integrated with precipitation observation for the first time.It is found from the observational study that during the Indian summer monsoon,aerosols from South Asia have a distinct activation effect on the cloud-precipitation process over the MQ.Under dynamic lifting,the increase in aerosols,which inhibits and delays weak precipitation over the MQ,instead intensifies the development of clouds over the MQ,leading to heavy precipitation on the north slope.The synergy of the MQ thermal-dynamic driving mechanism and the aerosol activation effect can trigger the deep convection in the precipitation process on the north slope of the MQ.Cloud development is more intense with the aerosol activation effect,and the diurnal cycle of convective clouds in the vertical change over the MQ presents a lag response to changing aerosols.From the perspective of climate impact on interannual variations,it can also be found that the frequency of light rain over the MQ present the significantly decreased trend,while the frequency of moderate to heavy precipitation on the north slope has a significantly increased trend,revealing the differentiated changes in the precipitation on the south and north slopes of the MQ under the influence of the aerosol activation effect on the cloud-precipitation process.展开更多
Triboelectric nanogenerators(TENGs)have recently drawn much attention in the field of biomechanical energy harvesting and motion monitoring.However,the electrode stretchability and contact-separation model induced com...Triboelectric nanogenerators(TENGs)have recently drawn much attention in the field of biomechanical energy harvesting and motion monitoring.However,the electrode stretchability and contact-separation model induced complicated packed structure remain a problem that heavily affects output performance during various human movements and requires to be urgently addressed.Here,a single-electrode piezotriboelectric hybrid nanogenerator(SEP-TENG)integrated with stretchable liquid-metal metal electrodes is reported,which simultaneously achieves outstanding energy harvesting performance and skincomfort human motion monitoring.A polarized piezoelectric BaTiO_(3)/silicon rubber(SR)composites film is served as the effective negative tribomaterial,benefiting from the improved dielectric constant and piezoelectric charge transfer,the optimized SEP-TENG generates a high peak power density of 5.7 W/m^(2) while contacted with human skin.Besides,owing to the ultralow Young's modulus of the SR encapsulation layer and tribo-piezoelectric hybrid layer,the homogeneous integrated multilayer composite serves no break till a 745%elongation,promoting that the SEP-TENG could effectively harvest biomechanical energy and realize stable power supplying for wearable electronics even under large deformation state.Furthermore,the SEP-TENG could comfortably attach to the finger joints and collect bending energy.This work provides a novel design methodology for a single-electrode TENG to realize omnidirectional biomechanical energy harvesting and motion monitoring.展开更多
Two novel monobenzo porphyrazines bearing nitro and methoxyl respectively on fused benzene ring were suc- cessfully synthesized. Also, an asymmetrical porphyrazine with one butylthio branch at the pyrrolic p-position ...Two novel monobenzo porphyrazines bearing nitro and methoxyl respectively on fused benzene ring were suc- cessfully synthesized. Also, an asymmetrical porphyrazine with one butylthio branch at the pyrrolic p-position sub- stituted by hydrogen atom was successfully isolated in the course of synthesis of symmetric octakis（butylthio） porphyrazine. Their corresponding cobalt complexes were subsequently obtained and characterized. Their catalytic ability was assessed by aerobic oxidation of benzoin, showing the highest benzil yield of 95.2% for 60 min. A pos- sible mechanism was also presented from the in-situ UV-Vis spectra, in which a novel and characteristic absorption peak of metal-oxo was observed. At the same time, similar results of the extended oxidation of benzyl alcohol also confirmed the reactive mechanism.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21272281 and 20977115)Natural Science Foundation of Hubei Province (2014CFB919)+1 种基金"the Fundamental Research Funds for the Central Universities", South-Central University for Nationalities (CZY14003)the Science and Technology Plan Innovation Team of Wuhan City (2015070504020220)
文摘A novel magnetically recoverable thioporphyrazine catalyst（CoPz（S-Bu）8/SiO2@Fe3O4） was prepared by immobilization of the cobalt octkis（butylthio） porphyrazine complex（CoPz（S-Bu）8） on silica-coated magnetic nanospheres（SiO2@Fe3O4）. The composite CoPz（S-Bu）8/SiO2@Fe3O4appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide（H2O2） as oxidant under Xe-lamp irradiation,with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number（TON） of 61.7 at ambient temperature. The biomimetic catalyst CoPz（S-Bu）8was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz（S-Bu）8can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,2019QZKK0105)the Major Science and Technology Project of Xizang Autonomous Region(XZ202402ZD0006-06).
文摘Can the“Roof of the world”Mount Qomolangma(MQ)serve as a“natural laboratory”for the activation effect of aerosols on the cloud-precipitation process?Here,we carried out the vertical observations of aerosols,clouds,and precipitation at the MQ,where the dual-radar active remote sensing technique is integrated with precipitation observation for the first time.It is found from the observational study that during the Indian summer monsoon,aerosols from South Asia have a distinct activation effect on the cloud-precipitation process over the MQ.Under dynamic lifting,the increase in aerosols,which inhibits and delays weak precipitation over the MQ,instead intensifies the development of clouds over the MQ,leading to heavy precipitation on the north slope.The synergy of the MQ thermal-dynamic driving mechanism and the aerosol activation effect can trigger the deep convection in the precipitation process on the north slope of the MQ.Cloud development is more intense with the aerosol activation effect,and the diurnal cycle of convective clouds in the vertical change over the MQ presents a lag response to changing aerosols.From the perspective of climate impact on interannual variations,it can also be found that the frequency of light rain over the MQ present the significantly decreased trend,while the frequency of moderate to heavy precipitation on the north slope has a significantly increased trend,revealing the differentiated changes in the precipitation on the south and north slopes of the MQ under the influence of the aerosol activation effect on the cloud-precipitation process.
基金This work was supported by the National Key R&D Program of China(grant numbers 2019YFB2004802,2019YFE0120300)National Natural Science Foundation of China(grant numbers 51975542,52175554)+1 种基金National Defense Fundamental Research Project,Shanxi province key laboratory of quantum sensing and precision measurement(grant number 201905D121001)Natural Science Foundation of Shanxi Province(grant numbers 20210302123059,201801D121152).
文摘Triboelectric nanogenerators(TENGs)have recently drawn much attention in the field of biomechanical energy harvesting and motion monitoring.However,the electrode stretchability and contact-separation model induced complicated packed structure remain a problem that heavily affects output performance during various human movements and requires to be urgently addressed.Here,a single-electrode piezotriboelectric hybrid nanogenerator(SEP-TENG)integrated with stretchable liquid-metal metal electrodes is reported,which simultaneously achieves outstanding energy harvesting performance and skincomfort human motion monitoring.A polarized piezoelectric BaTiO_(3)/silicon rubber(SR)composites film is served as the effective negative tribomaterial,benefiting from the improved dielectric constant and piezoelectric charge transfer,the optimized SEP-TENG generates a high peak power density of 5.7 W/m^(2) while contacted with human skin.Besides,owing to the ultralow Young's modulus of the SR encapsulation layer and tribo-piezoelectric hybrid layer,the homogeneous integrated multilayer composite serves no break till a 745%elongation,promoting that the SEP-TENG could effectively harvest biomechanical energy and realize stable power supplying for wearable electronics even under large deformation state.Furthermore,the SEP-TENG could comfortably attach to the finger joints and collect bending energy.This work provides a novel design methodology for a single-electrode TENG to realize omnidirectional biomechanical energy harvesting and motion monitoring.
基金This work was financially supported by National Natural Science Foundation of China （Nos. 20977115 and 21272281）, Natural Science Foundation of Hubei Province （No. 2014CFB919） and the S＆T Plan Innovation team of Wuhan city （No. 2015070504020220）.
文摘Two novel monobenzo porphyrazines bearing nitro and methoxyl respectively on fused benzene ring were suc- cessfully synthesized. Also, an asymmetrical porphyrazine with one butylthio branch at the pyrrolic p-position sub- stituted by hydrogen atom was successfully isolated in the course of synthesis of symmetric octakis（butylthio） porphyrazine. Their corresponding cobalt complexes were subsequently obtained and characterized. Their catalytic ability was assessed by aerobic oxidation of benzoin, showing the highest benzil yield of 95.2% for 60 min. A pos- sible mechanism was also presented from the in-situ UV-Vis spectra, in which a novel and characteristic absorption peak of metal-oxo was observed. At the same time, similar results of the extended oxidation of benzyl alcohol also confirmed the reactive mechanism.
