Two hydrocarbon degrading bacteria NJ276 and NJ341 were screened from 385 Antarctic marine bacteria and their degrading characteristics were studied. Diesel oil as sole carbon source was used in this study. The result...Two hydrocarbon degrading bacteria NJ276 and NJ341 were screened from 385 Antarctic marine bacteria and their degrading characteristics were studied. Diesel oil as sole carbon source was used in this study. The results showed that the oil degradation rates of Antarctic psychrophile bacteria NJ276 and NJ341 were 23.47 % and 32.15 %, respectively, after 20 days culturation at 5 ℃, and the rates were 43.95 % and 62.47 % respectively after 20 days culturation at 15 ℃. The oil degradation abilities were enhanced remarkably with the increasing culture temperature. GC - MSs indicated the residual oil contained C15 - C21 7 alkyls after degradation by NJ276, and C16, C17 and C18 3 alkyls after degradation by NJ341. The 16S rDNA gene sequences homology and phylogenetic analysis of the two Antarctic psychrophile bacteria showed that NJ276 belonged to the described genus Pseudoalteromonas and NJ341 belonged to the genus Colwellia.展开更多
[Objective] The aim was to provide direction for the development of flowers and plants industry at Beibei area of Chongqing.[Method] Effects of temperature ranges and influencing time of chilling damages in winter on ...[Objective] The aim was to provide direction for the development of flowers and plants industry at Beibei area of Chongqing.[Method] Effects of temperature ranges and influencing time of chilling damages in winter on local flowers and plants at Beibei area were analyzed,using extreme minimum temperature data during 1960 to 2009 and the phenological growth conditions and phenological observation data of Bougainvillea spectabilis Willd and Michelia champaca during 2005 to 2007 at Beibei area.[Result] Chilling damages affecting flowers and plants at Beibei area mostly emerged from late December to early February,the effects of which were relative serious in January with a temperature range from-2 to 5 ℃;the optimum temperatures were 12-28 ℃ for flowers and plants grown at Beibei area in Chongqing,being higher or lower than that temperature range will affect the normally overwintering flowering and growing;chilling damages affecting the flower seedlings would appear when being at extreme minimum temperatures lower than 6 ℃ for 3 d in any phenophase in winter.[Conclusion] According to the characters of chilling damages in winter,the influences of which on flowers and plants can be reduced through combining tendency prediction and adopting corresponding measures.展开更多
With the consideration of the thermal management and heat sink requirements,a cooling device is designed and the thermal resistance of this device is calculated with a single 5 W power LED.The thermal design of a sing...With the consideration of the thermal management and heat sink requirements,a cooling device is designed and the thermal resistance of this device is calculated with a single 5 W power LED.The thermal design of a single 5 W power LED is reasonable,effective and the result has been simulated.This design also instruct other power LEDs' thermal design.Provided is a reliable and effective method for the design of power LED illumination lamps and lanterns.展开更多
Superluminescence diode(SLD) modules with wide spectrum characteristics are required in fiber gyroscopes. A 1.3 μm butterfly packaged superluminescence diode with the spectrum width over 30 nm is reported and recent ...Superluminescence diode(SLD) modules with wide spectrum characteristics are required in fiber gyroscopes. A 1.3 μm butterfly packaged superluminescence diode with the spectrum width over 30 nm is reported and recent advances in process of SLD is described in the paper. The SLD modules have been applied to fiber gyroscopes.展开更多
LiFePO4 was prepared by heating the pre-decomposed precursor mixtures sealed in vacuum quartz-tube. Three kinds of cooling modes including nature cooling, air quenching, and water quenching were applied to comparing t...LiFePO4 was prepared by heating the pre-decomposed precursor mixtures sealed in vacuum quartz-tube. Three kinds of cooling modes including nature cooling, air quenching, and water quenching were applied to comparing the effects of cooling modes on the microstructure and electrochemical characteristics of the material. The results indicate that the water quenching mode can control overgrowth of the grain size of final product and improve its electrochemical performance compared with nature cooling mode and air quenching mode. The sample synthesized by using water quenching mode is of the highest reversible discharge specific capacity and the best cyclic electrochemical performance, demonstrating the first discharge capacity of 138.1 mA·h/g at 0.1C rate and the total loss of capacity of 3.11% after 20 cycles.展开更多
In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The t...In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The two cathodes were placed symmetrically at two ends of the anode. The modifications were decrease the length of the cylindrical anode to 4 cm instead of 6 cm, transform the copper emission electrode shape from plate of 40 mm length, 25 mm width and 2 mm thickness to disc of 20 mm diameter and 2 mm thickness and transform the inner uncovered area of the emission electrode from slit of 30 mm length and 10 mm width to disc of 5 mm diameter. The copper emission electrode was placed in the middle of the cylindrical anode and has aperture in the center of different diameters. Faraday cup was placed at different distances from the emission electrode aperture. The electrical discharge and the output ion beam characteristics of the modified ion source were measured at different pressures using argon gas. It was found that the optimum operating conditions of the modified ion source are; anode-cathode distance equal to 6 mm, emission electrode aperture diameter equal to 2.5 mm and emission electrode aperture, Faraday cup distance equals 3 cm. The effect of axial samarium cobalt permanent magnet of intensity equal to 300 Gauss on the discharge characteristics of the ion source was determined.展开更多
We performed high-level ab initio calculations on electronic structure of Na K. The potential energy curves (PECs) of 10 Λ-S states correlated with the three lowest dissociation limits have been calculated. On the ba...We performed high-level ab initio calculations on electronic structure of Na K. The potential energy curves (PECs) of 10 Λ-S states correlated with the three lowest dissociation limits have been calculated. On the basis of the calculated PECs, the spectroscopic constants of the boundΛ-S states are obtained, which are in good agreement with experimental results. The maximum vibrational quantum numbers of the singlet ground state X^1Σ^+ and the triplet ground state a^3Σ^+ have been analyzed with the semiclassical scattering theory. Transition properties including transition dipole moments, Franck-Condon factors, and radiative lifetimes have been investigated. The research results indicate that such calculations can provide fairly reliable estimation of parameters for the ultracold alkali diatomic molecular experiment.展开更多
基金the Natural Science Foundation of China(No.40876107).
文摘Two hydrocarbon degrading bacteria NJ276 and NJ341 were screened from 385 Antarctic marine bacteria and their degrading characteristics were studied. Diesel oil as sole carbon source was used in this study. The results showed that the oil degradation rates of Antarctic psychrophile bacteria NJ276 and NJ341 were 23.47 % and 32.15 %, respectively, after 20 days culturation at 5 ℃, and the rates were 43.95 % and 62.47 % respectively after 20 days culturation at 15 ℃. The oil degradation abilities were enhanced remarkably with the increasing culture temperature. GC - MSs indicated the residual oil contained C15 - C21 7 alkyls after degradation by NJ276, and C16, C17 and C18 3 alkyls after degradation by NJ341. The 16S rDNA gene sequences homology and phylogenetic analysis of the two Antarctic psychrophile bacteria showed that NJ276 belonged to the described genus Pseudoalteromonas and NJ341 belonged to the genus Colwellia.
文摘[Objective] The aim was to provide direction for the development of flowers and plants industry at Beibei area of Chongqing.[Method] Effects of temperature ranges and influencing time of chilling damages in winter on local flowers and plants at Beibei area were analyzed,using extreme minimum temperature data during 1960 to 2009 and the phenological growth conditions and phenological observation data of Bougainvillea spectabilis Willd and Michelia champaca during 2005 to 2007 at Beibei area.[Result] Chilling damages affecting flowers and plants at Beibei area mostly emerged from late December to early February,the effects of which were relative serious in January with a temperature range from-2 to 5 ℃;the optimum temperatures were 12-28 ℃ for flowers and plants grown at Beibei area in Chongqing,being higher or lower than that temperature range will affect the normally overwintering flowering and growing;chilling damages affecting the flower seedlings would appear when being at extreme minimum temperatures lower than 6 ℃ for 3 d in any phenophase in winter.[Conclusion] According to the characters of chilling damages in winter,the influences of which on flowers and plants can be reduced through combining tendency prediction and adopting corresponding measures.
文摘With the consideration of the thermal management and heat sink requirements,a cooling device is designed and the thermal resistance of this device is calculated with a single 5 W power LED.The thermal design of a single 5 W power LED is reasonable,effective and the result has been simulated.This design also instruct other power LEDs' thermal design.Provided is a reliable and effective method for the design of power LED illumination lamps and lanterns.
文摘Superluminescence diode(SLD) modules with wide spectrum characteristics are required in fiber gyroscopes. A 1.3 μm butterfly packaged superluminescence diode with the spectrum width over 30 nm is reported and recent advances in process of SLD is described in the paper. The SLD modules have been applied to fiber gyroscopes.
基金Project(50604018) supported by the National Natural Science Foundation of China
文摘LiFePO4 was prepared by heating the pre-decomposed precursor mixtures sealed in vacuum quartz-tube. Three kinds of cooling modes including nature cooling, air quenching, and water quenching were applied to comparing the effects of cooling modes on the microstructure and electrochemical characteristics of the material. The results indicate that the water quenching mode can control overgrowth of the grain size of final product and improve its electrochemical performance compared with nature cooling mode and air quenching mode. The sample synthesized by using water quenching mode is of the highest reversible discharge specific capacity and the best cyclic electrochemical performance, demonstrating the first discharge capacity of 138.1 mA·h/g at 0.1C rate and the total loss of capacity of 3.11% after 20 cycles.
文摘In this paper, design and construction of a modified cold molybdenum cathode Penning ion source was described. It consists of copper cylindrical anode with two cone ends and two movable cold molybdenum cathodes. The two cathodes were placed symmetrically at two ends of the anode. The modifications were decrease the length of the cylindrical anode to 4 cm instead of 6 cm, transform the copper emission electrode shape from plate of 40 mm length, 25 mm width and 2 mm thickness to disc of 20 mm diameter and 2 mm thickness and transform the inner uncovered area of the emission electrode from slit of 30 mm length and 10 mm width to disc of 5 mm diameter. The copper emission electrode was placed in the middle of the cylindrical anode and has aperture in the center of different diameters. Faraday cup was placed at different distances from the emission electrode aperture. The electrical discharge and the output ion beam characteristics of the modified ion source were measured at different pressures using argon gas. It was found that the optimum operating conditions of the modified ion source are; anode-cathode distance equal to 6 mm, emission electrode aperture diameter equal to 2.5 mm and emission electrode aperture, Faraday cup distance equals 3 cm. The effect of axial samarium cobalt permanent magnet of intensity equal to 300 Gauss on the discharge characteristics of the ion source was determined.
基金supported by the National Key Research and Development Program of China(No.2017YFA0304900,No.2017YFA0402300,and No.2016YFA0300600)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB28000000 and No.XDB07030000)+2 种基金the National Natural Science Foundation of China(No.11604334,No.11575099 and No.11474347)the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(No.KF201807)the Science Challenge Project(No.TZ2016005)
文摘We performed high-level ab initio calculations on electronic structure of Na K. The potential energy curves (PECs) of 10 Λ-S states correlated with the three lowest dissociation limits have been calculated. On the basis of the calculated PECs, the spectroscopic constants of the boundΛ-S states are obtained, which are in good agreement with experimental results. The maximum vibrational quantum numbers of the singlet ground state X^1Σ^+ and the triplet ground state a^3Σ^+ have been analyzed with the semiclassical scattering theory. Transition properties including transition dipole moments, Franck-Condon factors, and radiative lifetimes have been investigated. The research results indicate that such calculations can provide fairly reliable estimation of parameters for the ultracold alkali diatomic molecular experiment.
