The quantitative rules of the transfer and variation of errors,when the Gaussian integral functions F.(z) are evaluated sequentially by recurring,have been expounded.The traditional viewpoint to negate the applicabili...The quantitative rules of the transfer and variation of errors,when the Gaussian integral functions F.(z) are evaluated sequentially by recurring,have been expounded.The traditional viewpoint to negate the applicability and reliability of upward recursive formula in principle is amended.An optimal scheme of upward-and downward-joint recursions has been developed for the sequential F(z) computations.No additional accuracy is needed with the fundamental term of recursion because the absolute error of Fn(z) always decreases with the recursive approach.The scheme can be employed in modifying any of existent subprograms for Fn<z> computations.In the case of p-d-f-and g-type Gaussians,combining this method with Schaad's formulas can reduce,at least,the additive operations by a factor 40%;the multiplicative and exponential operations by a factor 60%.展开更多
Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate(SGR) and chlorophyll fluorescen...Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate(SGR) and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50,and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence( Fv / Fm) were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO 4-P. The photosynthetic capacity of photosystem II(PSII) was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO3-N concentrations were greater than 1.0 mmol/L and when PO4- P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera,these data contribute important information to ensure optimal results.展开更多
Phytoplankton physiologies are dynamic and have sensitive responses to the ambient environment. In this paper, we examine photosynthetic physiologies of phytoplankton communities with Phyto-PAM in the eastern equatori...Phytoplankton physiologies are dynamic and have sensitive responses to the ambient environment. In this paper, we examine photosynthetic physiologies of phytoplankton communities with Phyto-PAM in the eastern equatorial Indian Ocean during the spring inter-monsoon. Environmental parameters were measured to investigate the coupling between phytoplankton photosynthetic physiologies and their habitats. During the cruise, the water column was highly stratified. The mixed layer extended to about 75 m and was characterized by high temperature (>28°C) and low nutrient level. The Fv/Fm values and chlorophyll a (Chl a) concentrations were lower at the surface, as consequences of nutrient depletion and photo-inhibition. Subsurface Chl a maximum (SCM) occurred between 75 and 100 m, and had the highest Fv/Fm values. The formation of SCM was a balance between nutrient availability and light limitation. The SCM may contribute significantly to pelagic food web and primary production in the water column. Phytoplankton in different layers encountered different light, trophic and hydrographic dynamics and evolved distinct photosynthetic characteristics. Despite of co-limitation of nutrient limitation and photo-inhibition, phytoplankton in the surface layer showed their acclimation to high irradiance, had lower light utilization efficiencies (α: 0.061±0.032) and could exploit a wide range of light irradiance. Whereas, phytoplankton in the SCM layers presented the highest light utilization efficiencies (α: 0.146±0.48), which guaranteed higher photosynthetic capacities under low light level. These results provide insights into phytoplankton photo-adaption strategies in this less explored region.展开更多
文摘The quantitative rules of the transfer and variation of errors,when the Gaussian integral functions F.(z) are evaluated sequentially by recurring,have been expounded.The traditional viewpoint to negate the applicability and reliability of upward recursive formula in principle is amended.An optimal scheme of upward-and downward-joint recursions has been developed for the sequential F(z) computations.No additional accuracy is needed with the fundamental term of recursion because the absolute error of Fn(z) always decreases with the recursive approach.The scheme can be employed in modifying any of existent subprograms for Fn<z> computations.In the case of p-d-f-and g-type Gaussians,combining this method with Schaad's formulas can reduce,at least,the additive operations by a factor 40%;the multiplicative and exponential operations by a factor 60%.
文摘《电机学——机电能量转换》一书(汤蕴璆主编机械工业出版社 1981年)在推导如图所示: 电磁铁的磁场力时得出公式:f_m=(W_m(i,x))/(()x)(第66页,公式2—22)f_m 表示可动铁轭即衔铁所受的磁场力,W_m(i,x)表示磁场储能,它是铁芯线圈电流 i 和衔铁位置坐标 x 的函数。书中在导出该式时假设铁芯线圈的自感与流过电流无关,即磁路为线性,然后对公式解释说:“
基金Supported by the Technology Program of Basic Research of Qingdao(No.12-1-4-8-(2)-jch)
文摘Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate(SGR) and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50,and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence( Fv / Fm) were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO 4-P. The photosynthetic capacity of photosystem II(PSII) was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO3-N concentrations were greater than 1.0 mmol/L and when PO4- P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera,these data contribute important information to ensure optimal results.
基金The Global Change and Air-Sea Interaction Program under contract No.GASI-03-01-03-03the S&T Innovation Project of the Qingdao National Laboratory for Marine Science and Technology under contract No.2016ASKJ14the FIO Basic Research Fund under contract No.2013T04
文摘Phytoplankton physiologies are dynamic and have sensitive responses to the ambient environment. In this paper, we examine photosynthetic physiologies of phytoplankton communities with Phyto-PAM in the eastern equatorial Indian Ocean during the spring inter-monsoon. Environmental parameters were measured to investigate the coupling between phytoplankton photosynthetic physiologies and their habitats. During the cruise, the water column was highly stratified. The mixed layer extended to about 75 m and was characterized by high temperature (>28°C) and low nutrient level. The Fv/Fm values and chlorophyll a (Chl a) concentrations were lower at the surface, as consequences of nutrient depletion and photo-inhibition. Subsurface Chl a maximum (SCM) occurred between 75 and 100 m, and had the highest Fv/Fm values. The formation of SCM was a balance between nutrient availability and light limitation. The SCM may contribute significantly to pelagic food web and primary production in the water column. Phytoplankton in different layers encountered different light, trophic and hydrographic dynamics and evolved distinct photosynthetic characteristics. Despite of co-limitation of nutrient limitation and photo-inhibition, phytoplankton in the surface layer showed their acclimation to high irradiance, had lower light utilization efficiencies (α: 0.061±0.032) and could exploit a wide range of light irradiance. Whereas, phytoplankton in the SCM layers presented the highest light utilization efficiencies (α: 0.146±0.48), which guaranteed higher photosynthetic capacities under low light level. These results provide insights into phytoplankton photo-adaption strategies in this less explored region.
