PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution o...PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution of the g-C3N4 nanosheets shows that it was significantly enhanced when PtPd alloy NPs were introduced as a co-catalyst. The 0.2 wt% PtPd/g-C3N4 composite photocatalyst gave a maximum H2 production rate of 1600.8 μmol g^–1 h^–1. Furthermore, when K2HPO4 was added to the reaction system, the H2 production rate increased to 2885.0 μmol g^–1 h^–1. The PtPd/g-C3N4 photocatalyst showed satisfactory photocatalytic stability and was able to maintain most of its photocatalytic activity after four experimental photocatalytic cycles. In addition, a possible mechanism for the enhanced photocatalytic activity was proposed and verified by various photoelectric techniques. These results demonstrate that the synergistic effect between PtPd and g-C3N4 helps to greatly improve the photocatalytic activity of the composite photocatalyst.展开更多
Phrynocephalus vlangalii are widely distributed on Tibetan plateau spanning diverse altitudes and habitats. In the present study, P vlangalii were exposed to 8% oxygen concentration in a hypoxic chamber for 6 weeks. T...Phrynocephalus vlangalii are widely distributed on Tibetan plateau spanning diverse altitudes and habitats. In the present study, P vlangalii were exposed to 8% oxygen concentration in a hypoxic chamber for 6 weeks. Then the body temperature （Tb）, standard metabolic rate （SMR）, heart rate and metabolic enzyme activities of the lizards were measured at 20℃ and 30℃. The results indicated that hypoxia exposure decreased Tb, SMR and heart rate. Lactate dehydrogenase （LDH） activity of 8% 02 group became significant elevated in liver and skeletal muscle compared with control group at 20℃, but descended significantly in heart. Using electrophoresis we found that LDH contains five isozymes （LDH1, LDH2, LDH3, LDH4 and LDH5） and are expressed specifically in liver, skeletal muscle and heart. Citrate synthase （CS） activity in the liver also decreased at 20℃ and 30℃. No significant difference of CS activity was found between the two groups in skeletal muscle and heart.展开更多
Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocel...Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocellata was cloned using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE）. The sequence contains a 1497 bp open reading frame, which encodes a 498 amino acid protein with a predicted molecular weight of 55.45 kDa. EmSox9 displays high similarity to those of reptiles, and shows an overall amino acid identity of 〉82%. We also investigated the tissue-specific expression of EmSox9 mRNA by realtime quantitative PCR. Sox9 mRNA is present in brain, heart, liver, kidney, gonads and muscle tissues of adult E. multiocellata, with the highest expression in brain and testis. The results indicate that Sox9 may play important roles in some tissues during E. multiocellata neural and gonadal development.展开更多
The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on ...The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on proton transfer.The mechanism of hydrogen bond enhancement is qualitatively elucidated by comparing the infrared spectra, the reduced density gradient, and the frontier molecular orbitals.The calculated electronic spectra are consistent with the experimental results.To quantify the proton transfer, the potential energy curves(PECs) of the four derivatives in S0 and S1 states are scanned.It is concluded that the ability of proton transfer follows the order: FM > BFM > BFBC > CCM.展开更多
基金supported by the National Natural Science Foundation of China(51572295,21273285,21003157)the Beijing Nova Program(2008B76)the Science Foundation of China University of Petroleum Beijing(KYJJ2012-06-20 and 2462016YXBS05)~~
文摘PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution of the g-C3N4 nanosheets shows that it was significantly enhanced when PtPd alloy NPs were introduced as a co-catalyst. The 0.2 wt% PtPd/g-C3N4 composite photocatalyst gave a maximum H2 production rate of 1600.8 μmol g^–1 h^–1. Furthermore, when K2HPO4 was added to the reaction system, the H2 production rate increased to 2885.0 μmol g^–1 h^–1. The PtPd/g-C3N4 photocatalyst showed satisfactory photocatalytic stability and was able to maintain most of its photocatalytic activity after four experimental photocatalytic cycles. In addition, a possible mechanism for the enhanced photocatalytic activity was proposed and verified by various photoelectric techniques. These results demonstrate that the synergistic effect between PtPd and g-C3N4 helps to greatly improve the photocatalytic activity of the composite photocatalyst.
基金supported by the National Natural Science Foundation of China(Nos.31272313 and 31472005 to Q.CHEN)Fundamental Research Funds for the Central Universities(lzujbky-2015-81 to X,L.Tang)
文摘Phrynocephalus vlangalii are widely distributed on Tibetan plateau spanning diverse altitudes and habitats. In the present study, P vlangalii were exposed to 8% oxygen concentration in a hypoxic chamber for 6 weeks. Then the body temperature （Tb）, standard metabolic rate （SMR）, heart rate and metabolic enzyme activities of the lizards were measured at 20℃ and 30℃. The results indicated that hypoxia exposure decreased Tb, SMR and heart rate. Lactate dehydrogenase （LDH） activity of 8% 02 group became significant elevated in liver and skeletal muscle compared with control group at 20℃, but descended significantly in heart. Using electrophoresis we found that LDH contains five isozymes （LDH1, LDH2, LDH3, LDH4 and LDH5） and are expressed specifically in liver, skeletal muscle and heart. Citrate synthase （CS） activity in the liver also decreased at 20℃ and 30℃. No significant difference of CS activity was found between the two groups in skeletal muscle and heart.
基金supported by the National Natural Science Foundation of China (No. 30670263)
文摘Sox9 is an important member of Sox family which is involved in a variety of developmental processes including sex determination and gonadal differentiation. The cDNA of Sox9 from multiocellated racerunner E. multiocellata was cloned using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE）. The sequence contains a 1497 bp open reading frame, which encodes a 498 amino acid protein with a predicted molecular weight of 55.45 kDa. EmSox9 displays high similarity to those of reptiles, and shows an overall amino acid identity of 〉82%. We also investigated the tissue-specific expression of EmSox9 mRNA by realtime quantitative PCR. Sox9 mRNA is present in brain, heart, liver, kidney, gonads and muscle tissues of adult E. multiocellata, with the highest expression in brain and testis. The results indicate that Sox9 may play important roles in some tissues during E. multiocellata neural and gonadal development.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874241,11847224,and 11804195)the Shandong Province Higher Educational Science and Technology Program,China(Grant No.J15LJ03)+1 种基金the Taishan Scholar Project of Shandong Province,China,China Post-Doctoral Foundation(Grant No.2018M630796)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2018BA034)
文摘The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on proton transfer.The mechanism of hydrogen bond enhancement is qualitatively elucidated by comparing the infrared spectra, the reduced density gradient, and the frontier molecular orbitals.The calculated electronic spectra are consistent with the experimental results.To quantify the proton transfer, the potential energy curves(PECs) of the four derivatives in S0 and S1 states are scanned.It is concluded that the ability of proton transfer follows the order: FM > BFM > BFBC > CCM.
