The TiO2 based dye-sensitized solar cells doped with different sizes of ZnO nanorods were fabricated and studied by photoelectrochemical measurements. The results show that the energy conversion efficiency of the dye-...The TiO2 based dye-sensitized solar cells doped with different sizes of ZnO nanorods were fabricated and studied by photoelectrochemical measurements. The results show that the energy conversion efficiency of the dye-sensitized solar cells after the addition of ZnO nanorods(1%, mass fraction) was increased by 6%—20% in comparison with that without ZnO nanorods. The effect of different sizes of ZnO nanorods on the electronic transportation properties was studied in the composite semiconductor film by means of transient photovoltage technology(TPV). The result indicates that the electron diffusing velocity in N3-sensitized TiO2/ZnO film electrode was about 1—3 order of magnitude faster than that in TiO2 electrode. The experimental results indicate that the TiO2/ZnO electrode can improve the electron transport, decrease the recombination, enhance Voc, and increase efficiency of energy conversion.展开更多
As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was design...As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was designed as the sulfur host, in which MoO_2 is inlaid on the surface of ordered mesoporous carbons that can store active materials and provide fast electron transfer channel due to its ordered pore structure. The MoO_2 can effectively prevent the migration of polysulfides through the chemical adsorption and promote the conversion of polysulfides towards Li-sulfur battery.展开更多
14α-hydroxy-androst-4-ene-3,17-dione(14α-OH-AD)is an important precursor for the synthesis of steroid drugs with anticancer and carcinolytic activity.Initially,14α-OH-AD was mostly synthesized by whole-cell ferment...14α-hydroxy-androst-4-ene-3,17-dione(14α-OH-AD)is an important precursor for the synthesis of steroid drugs with anticancer and carcinolytic activity.Initially,14α-OH-AD was mostly synthesized by whole-cell fermentation of mold fungi using androstenedione(AD)as a substrate,which had difficulties in product isolation and purification as well as problems of high production cost.In this study,the source of the 14α-hydroxylase gene was expanded.And 14α-hydroxylase genes were heterologously expressed in Mycolicibacterium neoaurum(MNR)M3ΔksdD,which enabled the one-step biotransformation from the cheap substrate phytosterols(PS)to 14α-OH-AD,reducing the difficulty of product purification and production cost.What is more,to alleviate the problem of poor activity of 14α-hydroxylase,the 14α-hydroxylase gene was co-expressed with the electron transport chain element genes and the coenzyme regeneration genes,and a superior engineered strain MNR M3ΔksdD/pMV261-14α-G6PDH was obtained.Finally,the transformation conditions were optimized for the transformation of PS by the engineered strain.The molar yield of 14α-OH-AD reached to 60.4±2.3%(about 0.22 g/L productivity).This study investigated for the first time the effects of the tandem electron transport chain element genes and the tandem coenzyme regeneration genes on the 14α-hydroxylation reaction,providing a theoretical basis for the industrial production of 14α-OH-AD.展开更多
The performance of dye-sensitized solar cells （DSSCs） is strongly affected by the properties of semiconductor nanoparticles. In this work, we used TiO2 particles prepared by TiC14 hydrolysis n times on A1203 films ...The performance of dye-sensitized solar cells （DSSCs） is strongly affected by the properties of semiconductor nanoparticles. In this work, we used TiO2 particles prepared by TiC14 hydrolysis n times on A1203 films （A/T（n））, and investigated morphology, photoelectric, and electron transport properties of A/T（n）. The TiO2 shell was composed of 10-20 nm nanoparticles and the number of nanoparticles increased with increasing TIC14 treatment times. The highest photoelectric conversion efficiency of 3.23% was obtained as A/T（4）. IMPS results indicated that electron transport rate was high enough to conduct current, and was not the dominating effect to limit the Jsc. Jsc was mainly determined by dye loading on TiO2 and the interconnection of TiO2. These may provide a new strategy for preparing semiconductor working electrodes for DSSC.展开更多
Three series of novel 2-cyanoacrylates 7a--7f, 9a-9f, 10a--10f containing 1,3,4-thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II （PS II） electron transportation. Their structures...Three series of novel 2-cyanoacrylates 7a--7f, 9a-9f, 10a--10f containing 1,3,4-thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II （PS II） electron transportation. Their structures were clearly verified by lH NMR, 13C NMR, elemental analysis （or HRMS analysis） and single-crystal X-ray diffraction analysis. Bioassay showed that a suitable group at the 3-position of acrylates was essential for high herbicidal activ- ity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5-position of 1,3,4-thiadiazole decreased herbicidal activities.展开更多
文摘The TiO2 based dye-sensitized solar cells doped with different sizes of ZnO nanorods were fabricated and studied by photoelectrochemical measurements. The results show that the energy conversion efficiency of the dye-sensitized solar cells after the addition of ZnO nanorods(1%, mass fraction) was increased by 6%—20% in comparison with that without ZnO nanorods. The effect of different sizes of ZnO nanorods on the electronic transportation properties was studied in the composite semiconductor film by means of transient photovoltage technology(TPV). The result indicates that the electron diffusing velocity in N3-sensitized TiO2/ZnO film electrode was about 1—3 order of magnitude faster than that in TiO2 electrode. The experimental results indicate that the TiO2/ZnO electrode can improve the electron transport, decrease the recombination, enhance Voc, and increase efficiency of energy conversion.
基金supported by the National Natural Science Foundation of China(Nos. U1710109 and 51702182)Shenzhen Basic Research Project(No.JCYJ20150529164918734)
文摘As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was designed as the sulfur host, in which MoO_2 is inlaid on the surface of ordered mesoporous carbons that can store active materials and provide fast electron transfer channel due to its ordered pore structure. The MoO_2 can effectively prevent the migration of polysulfides through the chemical adsorption and promote the conversion of polysulfides towards Li-sulfur battery.
基金supported by the National Key R&D Program of China,Synthetic Biology Research(no.2019YFA0905300)the National Natural Science Foundation of China(21978221)+2 种基金the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-001-08)the Innovative Research Team of Tianjin Municipal Education Commission(TD13-5013)the Tianjin Municipal Science and Technology Commission(21ZYJDJC00030).
文摘14α-hydroxy-androst-4-ene-3,17-dione(14α-OH-AD)is an important precursor for the synthesis of steroid drugs with anticancer and carcinolytic activity.Initially,14α-OH-AD was mostly synthesized by whole-cell fermentation of mold fungi using androstenedione(AD)as a substrate,which had difficulties in product isolation and purification as well as problems of high production cost.In this study,the source of the 14α-hydroxylase gene was expanded.And 14α-hydroxylase genes were heterologously expressed in Mycolicibacterium neoaurum(MNR)M3ΔksdD,which enabled the one-step biotransformation from the cheap substrate phytosterols(PS)to 14α-OH-AD,reducing the difficulty of product purification and production cost.What is more,to alleviate the problem of poor activity of 14α-hydroxylase,the 14α-hydroxylase gene was co-expressed with the electron transport chain element genes and the coenzyme regeneration genes,and a superior engineered strain MNR M3ΔksdD/pMV261-14α-G6PDH was obtained.Finally,the transformation conditions were optimized for the transformation of PS by the engineered strain.The molar yield of 14α-OH-AD reached to 60.4±2.3%(about 0.22 g/L productivity).This study investigated for the first time the effects of the tandem electron transport chain element genes and the tandem coenzyme regeneration genes on the 14α-hydroxylation reaction,providing a theoretical basis for the industrial production of 14α-OH-AD.
基金Project supported by the National Materials Genome Project of China(Grant No.2016YFB0700600)the National Natural Science Foundation of China(Grant No.51673204)
文摘The performance of dye-sensitized solar cells （DSSCs） is strongly affected by the properties of semiconductor nanoparticles. In this work, we used TiO2 particles prepared by TiC14 hydrolysis n times on A1203 films （A/T（n））, and investigated morphology, photoelectric, and electron transport properties of A/T（n）. The TiO2 shell was composed of 10-20 nm nanoparticles and the number of nanoparticles increased with increasing TIC14 treatment times. The highest photoelectric conversion efficiency of 3.23% was obtained as A/T（4）. IMPS results indicated that electron transport rate was high enough to conduct current, and was not the dominating effect to limit the Jsc. Jsc was mainly determined by dye loading on TiO2 and the interconnection of TiO2. These may provide a new strategy for preparing semiconductor working electrodes for DSSC.
基金Project supported by the National Natural Science Foundation of China （NNSFC） （No. 20772068） and the National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science ＆ Technology of China （No. 2006BAE01A01-5）.
文摘Three series of novel 2-cyanoacrylates 7a--7f, 9a-9f, 10a--10f containing 1,3,4-thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II （PS II） electron transportation. Their structures were clearly verified by lH NMR, 13C NMR, elemental analysis （or HRMS analysis） and single-crystal X-ray diffraction analysis. Bioassay showed that a suitable group at the 3-position of acrylates was essential for high herbicidal activ- ity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5-position of 1,3,4-thiadiazole decreased herbicidal activities.
