The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform

Liya Xiong - One of the best experts on this subject based on the ideXlab platform.

  • IGARSS - Remote sensing approach to estimating net primary productivity of temperate deciduous forest in northeast China
    IEEE International IEEE International IEEE International Geoscience and Remote Sensing Symposium 2004. IGARSS '04. Proceedings. 2004, 2004
    Co-Authors: Liya Xiong
    Abstract:

    The application of remote sensing in the study of terrestrial ecosystem opens up an effective way for simulating terrestrial productivity. In this paper, a RUE model is established by parameterized plant photosynthesis and respiration. Photosynthetically active radiation absorbed by all surface materials (APARSFC), obtained by correcting photosynthetically active radiation observed by MODIS for the effects of surface albedo, atmospheric total transmittance, and periodical change of Solar incident Angle and Solar Hour Angle during daytime, together with the ratio of PAR absorbed by the canopy to APARSFC (RPAR) and radiation use efficiency (RUE) based on a relationship between RUE and maximum rate of leaf photosynthesis (Amax) governed by its dependence on seasonal dynamics of foliage nitrogen content, are used to estimate gross photosynthesis. Plant respiration is divided into growing respiration as constant fraction of GPP, and maintenance respiration from leaf, stem, and root. The model is adapted to calculate the net primary productivity (NPP) of temperate deciduous forest in northeast China, supported by auxiliary data composed of daily MODIS data, atmosphere profile, ice-snow cover and landform of the study area in June 2003. In June 2003, daily mean APARSFC of temperate deciduous forest in the study area reaches 8.1 MJ m-2day-1, RUE varies from 0.45 to 1.09 gC MJ-1, and monthly NPP is 0.53 MgC ha-1, 0.56 MgC ha-1 for temperate deciduous coniferous forest, 0.51 MgC ha-1 for temperate deciduous broadleaved forest. Compared with the process-based model, both of them are in agreement with simulated NPP

  • Remote sensing approach to estimating net primary productivity of temperate deciduous forest in northeast China
    IGARSS 2004. 2004 IEEE International Geoscience and Remote Sensing Symposium, 2004
    Co-Authors: Liya Xiong
    Abstract:

    The application of remote sensing in the study of terrestrial ecosystem opens up an effective way for simulating terrestrial productivity. In this paper, a RUE model is established by parameterized plant photosynthesis and respiration. Photosynthetically active radiation absorbed by all surface materials (APARSFC), obtained by correcting photosynthetically active radiation observed by MODIS for the effects of surface albedo, atmospheric total transmittance, and periodical change of Solar incident Angle and Solar Hour Angle during daytime, together with the ratio of PAR absorbed by the canopy to APARSFC (RPAR) and radiation use efficiency (RUE) based on a relationship between RUE and maximum rate of leaf photosynthesis (Amax) governed by its dependence on seasonal dynamics of foliage nitrogen content, are used to estimate gross photosynthesis. Plant respiration is divided into growing respiration as constant fraction of GPP, and maintenance respiration from leaf, stem, and root. The model is adapted to calculate the net primary productivity (NPP) of temperate deciduous forest in northeast China, supported by auxiliary data composed of daily MODIS data, atmosphere profile, ice-snow cover and landform of the study area in June 2003. In June 2003, daily mean APARSFC of temperate deciduous forest in the study area reaches 8.1 MJ m-2day-1, RUE varies from 0.45 to 1.09 gC MJ-1, and monthly NPP is 0.53 MgC ha-1, 0.56 MgC ha-1 for temperate deciduous coniferous forest, 0.51 MgC ha-1 for temperate deciduous broadleaved forest. Compared with the process-based model, both of them are in agreement with simulated NPP

Runsheng Tang - One of the best experts on this subject based on the ideXlab platform.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, [beta]3A, azimuth Angle of Solar panels in the morning and afternoon from due south, [phi]a, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, [omega]a, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of [beta]3A, [phi]a and [omega]a for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, β3A, azimuth Angle of Solar panels in the morning and afternoon from due south, ϕa, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, ωa, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of β3A, ϕa and ωa for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

Yi Ma - One of the best experts on this subject based on the ideXlab platform.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, [beta]3A, azimuth Angle of Solar panels in the morning and afternoon from due south, [phi]a, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, [omega]a, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of [beta]3A, [phi]a and [omega]a for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, β3A, azimuth Angle of Solar panels in the morning and afternoon from due south, ϕa, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, ωa, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of β3A, ϕa and ωa for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

Guihua Li - One of the best experts on this subject based on the ideXlab platform.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, [beta]3A, azimuth Angle of Solar panels in the morning and afternoon from due south, [phi]a, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, [omega]a, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of [beta]3A, [phi]a and [omega]a for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

  • Optical performance of vertical axis three azimuth Angles tracked Solar panels
    Applied Energy, 2011
    Co-Authors: Yi Ma, Guihua Li, Runsheng Tang
    Abstract:

    In this work, a new sun-tracking concept was proposed, and the optical performance of Solar panels with such sun-tracking system was theoretically investigated based on the developed mathematical method and monthly horizontal radiation. The mechanism of the proposed sun-tracking technique is that the azimuth Angle of Solar panels is daily adjusted three times at three fixed positions: eastward, southward and westward in the morning, noon, and afternoon, respectively, by rotating Solar panels about the vertical axis (3A sun-tracking, in short). The analysis indicated that the tilt-Angle of Solar panels, β3A, azimuth Angle of Solar panels in the morning and afternoon from due south, ϕa, and Solar Hour Angle when the azimuth Angle adjustment was made in the morning and afternoon, ωa, were three key parameters affecting the optical performance of such tracked Solar panels. Calculation results showed that, for 3A tracked Solar panels with a yearly fixed tilt-Angle, the maximum annual collectible radiation was above 92% of that on a Solar panel with full 2-axis sun-tracking; whereas for those with the tilt-Angle being seasonally adjusted, it was above 95%. Results also showed that yearly or seasonally optimal values of β3A, ϕa and ωa for maximizing annual Solar gain were related to site latitudes, and empirical correlations for a quick estimation of optimal values of these parameters were proposed based on climatic data of 32 sites in China.

Xiang Ming - One of the best experts on this subject based on the ideXlab platform.

  • influence of Solar Hour Angle in the position of focusing line on trough Solar concentrator
    Energy Engineering, 2008
    Co-Authors: Xiang Ming
    Abstract:

    Based on the influence of Solar Hour Angle in the position of focusing line on trough Solar concentrator,theoretical model for the loss of Solar irradiance caused by moving of focusing line was established.With analysis on the moving of focusing line and calculation for the loss of Solar irradiance at different Solar terms in Kunming under clear days,an universal law of the position of focusing line variation with Solar Hour Angle,the loss of instantaneous Solar irradiance and the relative loss rate of Solar irradiance in different period of time were obtained.A comparison between the experimental results and theoretical arithmetic was made,too.Some measures and suggestions for improvement of trough concentration system were given,which were founded on the characteristic of the moving of focusing line.It was shown that there was completely no need to take the loss of Solar irradiance caused by moving of focusing line into account for large-scale application of the trough Solar collector.