Photo-production of dissolved inorganic carbon （DIC） from chromophoric dissolved organic matter （CDOM） is an important transformation process in marine carbon cycle, but little is known about this process in Chine...Photo-production of dissolved inorganic carbon （DIC） from chromophoric dissolved organic matter （CDOM） is an important transformation process in marine carbon cycle, but little is known about this process in Chinese coastal systems. This study investigated an estuarine water sample and a coastal seawater sample from the subtropical waters in southeast of China. Water samples were exposed to natural sunlight and the absorption and fluorescence of CDOM as well as the DIC concentration were measured in the summer of 2009. The estuarine water had higher CDOM level, molecular weight and proportion of humic-like fluorescent components than the seawater that exhibited abundant tryptophan-like fluorescent component. After a 3-day irradiation, the CDOM level decreased by 45% in the estuarine water and 20% in the seawater, accompanied with a decrease in the molecular weight and aromaticity of DOM which was inferred from an increase in the absorption spectral slope parameter. The photo-degradation rates of all the five fluorescent components were also notable, in particular two humic-like components （C4 and C5） were removed by 78% and 69% in the estuarine water and by 69% and 56% in the seawater. The estuarine water had a higher photo-production rate of DIC than the seawater （4.4 vs. 2.5 μmol/（L-day））, in part due to its higher CDOM abundance. The differences in CDOM compositions between the twO types of waters might be responsible for the higher susceptibility of the estuarine water to photo-degradation and hence could also affect the photo-production process of DIC.展开更多
We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass ...We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass dependent skewness factor into the skewness effect.Then we extend the skewness improved model to the LHC energies.The numerical results of our model are in good agreement with theΨ/Ψ and Ψ（2S）data in ultraperipheral proton-proton collisions at LHC,which show the significance of the vector meson mass-dependent skewness factor.A prediction of the exclusive charmonium photo-production in ultra-peripheral nucleus-nucleus collisions is performed since it can provide a good way to test the effectiveness of the color glass condensate.展开更多
The Q^2 dependencies of Roper resonance (N~* (1440)) helicity amplitudes have been discussed based on twoassumptions:(i) the Roper resonance is an excitation of one of the three quarks,and (ii) the quarks are surround...The Q^2 dependencies of Roper resonance (N~* (1440)) helicity amplitudes have been discussed based on twoassumptions:(i) the Roper resonance is an excitation of one of the three quarks,and (ii) the quarks are surrounded bya pion-meson cloud.Our study shows that the mixing of the ground state in the Roper wavefunction caused by the pionmeson cloud together with the pion meson cloud itself is crucial for the predictions of the photoproduction amplitudesof the Roper resonance.It is found that our model can give a good description for the helicity amplitudes of the Roperresonance comparing with the experimental measurement.展开更多
为研究四甲基戊二酸(TGA)对夏玉米光合特征和产量的调控效应,2018、2019年在中国农业科学院新乡试验基地开展大田试验,以中单909(ZD909)和京农科728(JNK728)为试验材料,设置5个TGA施用梯度(0、75、150、225和300 g hm^-2)。结果表明,适...为研究四甲基戊二酸(TGA)对夏玉米光合特征和产量的调控效应,2018、2019年在中国农业科学院新乡试验基地开展大田试验,以中单909(ZD909)和京农科728(JNK728)为试验材料,设置5个TGA施用梯度(0、75、150、225和300 g hm^-2)。结果表明,适宜剂量的TGA处理可提高玉米产量、延缓玉米生育期内功能叶的衰老速率,增强灌浆期的净光合速率,试验条件下TGA的最佳施用量为150 g hm^-2。在TGA最佳施用量下,ZD909和JNK728的产量相比对照2年平均分别增加8.7%和11.7%。2个品种玉米生育期内叶绿素含量、可溶性蛋白含量和光合势相比对照平均分别增加14.3%和19.7%、18.7%和22.7%、10.9%和16.9%;而叶片衰老速率相比对照平均降低了55.9%和56.5%;灌浆期的净光合速率相比对照平均分别增加44.0%和58.4%。相关性分析表明,玉米产量与生育期内叶片衰老速率呈显著负相关,而与灌浆期净光合速率呈显著正相关。综上,TGA处理能够提高叶片叶绿素和可溶性蛋白含量,延缓玉米叶片衰老速率,并提高了灌浆期净光合速率,进而实现玉米增产。展开更多
以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。...以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。以强化底物传输和提高底物降解效率为目标,对反应器的实际操作参数进行了优化。研究结果表明,反应器的底物传输特性对反应器的底物降解效率有显著影响。反应器的底物降解效率随进口底物质量浓度的增加呈现先增大后减小的趋势。反应器的底物降解效率随流速的增加呈现逐渐减小的趋势。当反应器的进口底物质量浓度为10 g/L,流速为100 m L/h时,底物消耗速率最大,底物降解效率达到43.5%。合理地控制反应器中的底物传输使得生物膜区域具有适合的底物质量浓度分布,是维持反应器较高底物降解效率的有效途径。展开更多
Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was ev...Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was evaluated for the first time under specific experimental conditions (e.g., a biomass concentration of 0.34 ± 0.02 g, a light intensity of 150 μE.s<sup>-1</sup>.m<sup>-2</sup> and reaction times of 19.3 ± 1.2 h). The performance of this photosynthetic microorganism for producing hydrogen was successfully improved by the addition of sodium dithionite (a reducing agent) as an innovative method for increasing the gas production, and as a main contribution of this work. Quantitative gas chromatography (GC) analyses of H<sub>2</sub> to verify the production performance were successfully carried out at low concentration levels. GC analyses were performed by means of a conventional thermal conductivity detector coupled to a separation system of a Molecular Sieve column 500 mm × 3175 mm (L × ID). Low detection limits were consistently obtained with the GC system used. The separation of H<sub>2</sub> in culture samples was efficiently achieved in average retention times of 1.47 min. The H<sub>2</sub> produced in this process was subsequently used for power generation using a Proton Exchange Membrane Fuel Cell (PEMFC).展开更多
基金supported by the National Natural Science Foundation of China (No. 40776041, 40810069004)the National Basic Research Program (973) of China (No.2011CB409804)the Fundamental Research Funds for the Central Universities (No. 201112G011)
文摘Photo-production of dissolved inorganic carbon （DIC） from chromophoric dissolved organic matter （CDOM） is an important transformation process in marine carbon cycle, but little is known about this process in Chinese coastal systems. This study investigated an estuarine water sample and a coastal seawater sample from the subtropical waters in southeast of China. Water samples were exposed to natural sunlight and the absorption and fluorescence of CDOM as well as the DIC concentration were measured in the summer of 2009. The estuarine water had higher CDOM level, molecular weight and proportion of humic-like fluorescent components than the seawater that exhibited abundant tryptophan-like fluorescent component. After a 3-day irradiation, the CDOM level decreased by 45% in the estuarine water and 20% in the seawater, accompanied with a decrease in the molecular weight and aromaticity of DOM which was inferred from an increase in the absorption spectral slope parameter. The photo-degradation rates of all the five fluorescent components were also notable, in particular two humic-like components （C4 and C5） were removed by 78% and 69% in the estuarine water and by 69% and 56% in the seawater. The estuarine water had a higher photo-production rate of DIC than the seawater （4.4 vs. 2.5 μmol/（L-day））, in part due to its higher CDOM abundance. The differences in CDOM compositions between the twO types of waters might be responsible for the higher susceptibility of the estuarine water to photo-degradation and hence could also affect the photo-production process of DIC.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11765005,11305040,IRG11521064,11775097 and 11465021the Fund of Science and Technology Department of Guizhou Province under Grant No[2015]2114the Education Department of Guizhou Province under Grant No.KY[2017]004
文摘We calculate the exclusive charmonium photo-production in the framework of color glass condensate.To obtain a good description of the vector meson production experimental data at HERA,we introduce a vector meson mass dependent skewness factor into the skewness effect.Then we extend the skewness improved model to the LHC energies.The numerical results of our model are in good agreement with theΨ/Ψ and Ψ（2S）data in ultraperipheral proton-proton collisions at LHC,which show the significance of the vector meson mass-dependent skewness factor.A prediction of the exclusive charmonium photo-production in ultra-peripheral nucleus-nucleus collisions is performed since it can provide a good way to test the effectiveness of the color glass condensate.
基金National Natural Science Foundation of China under Grant No.10475088the CAS Knowledge Innovation Project under Grant No.KC2-SW-N02
文摘The Q^2 dependencies of Roper resonance (N~* (1440)) helicity amplitudes have been discussed based on twoassumptions:(i) the Roper resonance is an excitation of one of the three quarks,and (ii) the quarks are surrounded bya pion-meson cloud.Our study shows that the mixing of the ground state in the Roper wavefunction caused by the pionmeson cloud together with the pion meson cloud itself is crucial for the predictions of the photoproduction amplitudesof the Roper resonance.It is found that our model can give a good description for the helicity amplitudes of the Roperresonance comparing with the experimental measurement.
文摘为研究四甲基戊二酸(TGA)对夏玉米光合特征和产量的调控效应,2018、2019年在中国农业科学院新乡试验基地开展大田试验,以中单909(ZD909)和京农科728(JNK728)为试验材料,设置5个TGA施用梯度(0、75、150、225和300 g hm^-2)。结果表明,适宜剂量的TGA处理可提高玉米产量、延缓玉米生育期内功能叶的衰老速率,增强灌浆期的净光合速率,试验条件下TGA的最佳施用量为150 g hm^-2。在TGA最佳施用量下,ZD909和JNK728的产量相比对照2年平均分别增加8.7%和11.7%。2个品种玉米生育期内叶绿素含量、可溶性蛋白含量和光合势相比对照平均分别增加14.3%和19.7%、18.7%和22.7%、10.9%和16.9%;而叶片衰老速率相比对照平均降低了55.9%和56.5%;灌浆期的净光合速率相比对照平均分别增加44.0%和58.4%。相关性分析表明,玉米产量与生育期内叶片衰老速率呈显著负相关,而与灌浆期净光合速率呈显著正相关。综上,TGA处理能够提高叶片叶绿素和可溶性蛋白含量,延缓玉米叶片衰老速率,并提高了灌浆期净光合速率,进而实现玉米增产。
文摘以连续流产氢为目标,采用高透光性弥散光纤作为导光介质和光合细菌吸附成膜的载体,构造了环流型光纤生物膜制氢反应器。在实验研究的基础上,根据传质原理和Monod生化反应动力学建立了描述连续流反应器中底物传输和降解的二维数学模型。以强化底物传输和提高底物降解效率为目标,对反应器的实际操作参数进行了优化。研究结果表明,反应器的底物传输特性对反应器的底物降解效率有显著影响。反应器的底物降解效率随进口底物质量浓度的增加呈现先增大后减小的趋势。反应器的底物降解效率随流速的增加呈现逐渐减小的趋势。当反应器的进口底物质量浓度为10 g/L,流速为100 m L/h时,底物消耗速率最大,底物降解效率达到43.5%。合理地控制反应器中的底物传输使得生物膜区域具有适合的底物质量浓度分布,是维持反应器较高底物降解效率的有效途径。
文摘Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was evaluated for the first time under specific experimental conditions (e.g., a biomass concentration of 0.34 ± 0.02 g, a light intensity of 150 μE.s<sup>-1</sup>.m<sup>-2</sup> and reaction times of 19.3 ± 1.2 h). The performance of this photosynthetic microorganism for producing hydrogen was successfully improved by the addition of sodium dithionite (a reducing agent) as an innovative method for increasing the gas production, and as a main contribution of this work. Quantitative gas chromatography (GC) analyses of H<sub>2</sub> to verify the production performance were successfully carried out at low concentration levels. GC analyses were performed by means of a conventional thermal conductivity detector coupled to a separation system of a Molecular Sieve column 500 mm × 3175 mm (L × ID). Low detection limits were consistently obtained with the GC system used. The separation of H<sub>2</sub> in culture samples was efficiently achieved in average retention times of 1.47 min. The H<sub>2</sub> produced in this process was subsequently used for power generation using a Proton Exchange Membrane Fuel Cell (PEMFC).
