Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitro...Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitrogen compounds were investigated with N2 flux method,using a self-designed continuous flow through and auto-sampling system.The results indicate that the denitrification rates varied between 222 and 908 μmol/（m2·h） with an average of 499 μmol /（m2·h）.During incubation,the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/（m2·h）.The denitrification rates were highly correlated with the SOD（r2=0.77） regardless of the NO-3＋NO-2 concentrations in the overlying water,organic carbon contents in sediments and water temperature,suggesting that the SOD was probably the main environmental factor controlling the denitrification in the Qi＇ao Island coastal zone.There was a net flux of NO-3＋NO-2 into the sediments from the overlying water.The NH＋4 flux from sediments into water as the result of mineralization was between 12.3 and 210.3 μmol/（m2·h）,which seems limited by both organic carbon content in sediment and dissolved oxygen concentration in the overlying water.展开更多
1 The Cyclical Flow of the Sixty-Gan zhi Temporal Units 'Time for the Chinese is forever flowing without beginning or end',noted Thome H. Fang. And'it is customary for Chinese to use the kan-Chih(gan zhi)t...1 The Cyclical Flow of the Sixty-Gan zhi Temporal Units 'Time for the Chinese is forever flowing without beginning or end',noted Thome H. Fang. And'it is customary for Chinese to use the kan-Chih(gan zhi)to mark the passage of time.There are ten heavenly stems(gan)and twelve earthly branches(zhi),an alternating and sequential combination of the two makes a cycle of sixty years,months,days and two-hour period shi chen(时辰)in a day'. The sixty gan zhi temporal cycle is very important in the practice of Chinese medicine.It is an important practical temporal tool in the acupuncture practice of 子午流注(zi wu liu zhu)which is a method of choosing and using acupuncture points in dealing with a specific clinical pattern in accordance with the patient's temporal clotting and flowing of his/her Qi and blood.In addition,the sixty gan-zhi temporal cyclical system is also an important tool in forecasting adverse weather/climactic conditions and the illnesses that comes with them on the basis of the ancient methodology of 'the circulating five elements/phases and the six climactic influences'五运六气.Hence,I have included this gan zhi or celestial stems and earthly branches for each of the days in the Chinese Medical and Agricultural Lunisolar Calendar for the year of Rat wu zi nian(wu is the celestial stem while zi is the earthly branch for the year 2008).展开更多
基金The Key Program and General Program of the National Natural Science Foundation of China under contract Nos 40532011 and 40406010COMRA’s 11th Five Year Program under contract No. DYXM115-02-4-04the Natural Science Foundation of Guangdong Province under contract No.04300822
文摘Samples of sediments and the overlying water were collected in the Qi＇ao Island coastal zone,the Zhujiang（Pearl River） Estuary（ZE）.Denitrification rates,sediment oxygen demand（SOD）,and fluxes of inorganic nitrogen compounds were investigated with N2 flux method,using a self-designed continuous flow through and auto-sampling system.The results indicate that the denitrification rates varied between 222 and 908 μmol/（m2·h） with an average of 499 μmol /（m2·h）.During incubation,the sediments absorbed dissolved oxygen in the overlying water with SOD ranging from 300 to 2 363 μmol/（m2·h）.The denitrification rates were highly correlated with the SOD（r2=0.77） regardless of the NO-3＋NO-2 concentrations in the overlying water,organic carbon contents in sediments and water temperature,suggesting that the SOD was probably the main environmental factor controlling the denitrification in the Qi＇ao Island coastal zone.There was a net flux of NO-3＋NO-2 into the sediments from the overlying water.The NH＋4 flux from sediments into water as the result of mineralization was between 12.3 and 210.3 μmol/（m2·h）,which seems limited by both organic carbon content in sediment and dissolved oxygen concentration in the overlying water.
文摘1 The Cyclical Flow of the Sixty-Gan zhi Temporal Units 'Time for the Chinese is forever flowing without beginning or end',noted Thome H. Fang. And'it is customary for Chinese to use the kan-Chih(gan zhi)to mark the passage of time.There are ten heavenly stems(gan)and twelve earthly branches(zhi),an alternating and sequential combination of the two makes a cycle of sixty years,months,days and two-hour period shi chen(时辰)in a day'. The sixty gan zhi temporal cycle is very important in the practice of Chinese medicine.It is an important practical temporal tool in the acupuncture practice of 子午流注(zi wu liu zhu)which is a method of choosing and using acupuncture points in dealing with a specific clinical pattern in accordance with the patient's temporal clotting and flowing of his/her Qi and blood.In addition,the sixty gan-zhi temporal cyclical system is also an important tool in forecasting adverse weather/climactic conditions and the illnesses that comes with them on the basis of the ancient methodology of 'the circulating five elements/phases and the six climactic influences'五运六气.Hence,I have included this gan zhi or celestial stems and earthly branches for each of the days in the Chinese Medical and Agricultural Lunisolar Calendar for the year of Rat wu zi nian(wu is the celestial stem while zi is the earthly branch for the year 2008).
