Quantitative changes in main parameters of secondary xylem during aging process were studied in four trees of Pinus bungeana collected from two different sites.No marked difference was found in the width of heartwo...Quantitative changes in main parameters of secondary xylem during aging process were studied in four trees of Pinus bungeana collected from two different sites.No marked difference was found in the width of heartwood, transition zone and sapwood at four cardinal directions and a wider sapwood and a narrower heartwood were noted in fast grown trees than in slowly grown ones. Earlywood generally showed a higher percentage of aspirated pits than latewood regardless of the age and growth conditions of the trees in addition , the earliest dead cells and the last living cells in the marginal cells were found a bit earlier than those in the central cells. It thus seems appropriate to conclude that the death of cells results largely from decrease of fluid permeability as the number of aspirated pits increases during aging process.展开更多
Using remote sensing technology for water quality evaluation is an inevitable trend in marine environmental monitoring. However, fewer categories of water quality parameters can be monitored by remote sensing technolo...Using remote sensing technology for water quality evaluation is an inevitable trend in marine environmental monitoring. However, fewer categories of water quality parameters can be monitored by remote sensing technology than the 35 specified in GB3097-1997 Marine Water Quality Standard. Therefore, we considered which parameters must be selected by remote sensing and how to model for water quality evaluation using the finite parameters. In this paper, focused on Leizhou Peninsula nearshore waters, we found N, P, COD, PH and DO to be the dominant parameters of water quality by analyzing measured data. Then, mathematical statistics was used to determine that the relationship among the five parameters was COD〉DO〉P〉N〉pH. Finally, five-parameter, fourparameter and three-parameter water quality evaluation models were established and compared. The results showed that COD, DO, P and N were the necessary parameters for remote sensing evaluation of the Leizhou Peninsula nearshore water quality, and the optimal comprehensive water quality evaluation model was the four- parameter model. This work may serve as a reference for monitoring the quality of other marine waters by remote sensing.展开更多
文摘Quantitative changes in main parameters of secondary xylem during aging process were studied in four trees of Pinus bungeana collected from two different sites.No marked difference was found in the width of heartwood, transition zone and sapwood at four cardinal directions and a wider sapwood and a narrower heartwood were noted in fast grown trees than in slowly grown ones. Earlywood generally showed a higher percentage of aspirated pits than latewood regardless of the age and growth conditions of the trees in addition , the earliest dead cells and the last living cells in the marginal cells were found a bit earlier than those in the central cells. It thus seems appropriate to conclude that the death of cells results largely from decrease of fluid permeability as the number of aspirated pits increases during aging process.
基金The Science and Technology Project of Guangdong Province under contract No.2014A010103030the Postdoctoral Science Foundation of Zhejiang under contract No.BSH1301015the Supported by Foundation for Distinguished Young Talents in Higher Education of Guangdong Province No.GDOU2013050233
文摘Using remote sensing technology for water quality evaluation is an inevitable trend in marine environmental monitoring. However, fewer categories of water quality parameters can be monitored by remote sensing technology than the 35 specified in GB3097-1997 Marine Water Quality Standard. Therefore, we considered which parameters must be selected by remote sensing and how to model for water quality evaluation using the finite parameters. In this paper, focused on Leizhou Peninsula nearshore waters, we found N, P, COD, PH and DO to be the dominant parameters of water quality by analyzing measured data. Then, mathematical statistics was used to determine that the relationship among the five parameters was COD〉DO〉P〉N〉pH. Finally, five-parameter, fourparameter and three-parameter water quality evaluation models were established and compared. The results showed that COD, DO, P and N were the necessary parameters for remote sensing evaluation of the Leizhou Peninsula nearshore water quality, and the optimal comprehensive water quality evaluation model was the four- parameter model. This work may serve as a reference for monitoring the quality of other marine waters by remote sensing.
