The Beibu Gulf is at an important geographical location and rich in gas, oil and biological resources. The observed currents showed that the current in the upper layer was opposite to that in the lower layer in boreal...The Beibu Gulf is at an important geographical location and rich in gas, oil and biological resources. The observed currents showed that the current in the upper layer was opposite to that in the lower layer in boreal winter in the northern Beibu Gulf and it was northeastward in the lower layer. This northeastward current was reproduced by a 3 D baroclinic model in this study. It's found that the counter-wind deep current(referred to as ‘CWDC' hereinafter) strengthened from September to November but weakened from December to the following February. A closed meridional circulation in vertical direction was found in the northern Beibu Gulf, including CWDC, surface southwestward current, an upwelling, and a downwelling. The temporal variation process of the meridional circulation was similar to that of CWDC, with strength and range stronger in November and December than in other four months. Similar to the variation process of CWDC, the monsoon wind changed from weak easterly wind in September to strong northeasterly wind in November and December, and it was transformed into weak southeasterly wind in February again. The sensitive experiments showed that CWDC and the meridional circulation were controlled by the monsoon wind and were adjusted by heat flux-and tide-induced mixing, respectively. According to the momentum balance equation, it can be revealed the counter-wind deep current is a compensation current which is induced by the surface elevation gradient balanced by the Coriolis force, vertical diffusion and baroclinic pressure gradient.展开更多
With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater str...With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.展开更多
基金jointly supported by the National Natural Science Foundation of China (Nos. 41566001, 41406044 and 41576024)Guangxi Natural Science Foundation (Nos. 2015GXNSFCA139023, 2018JJD150011, 2016JJF15001 and 2015GXNSFAA139247)+5 种基金Guangxi Science and Technology Development Program (Guikegong 1598016-8)Guangxi Science and Technology Major Project (Guike AA18118025)Guangxi Key Research and Development Program (Guike AB16380282)Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Qinzhou University (No. 2017KF02)the Fundamental Research Funds of Guangxi Academy of Sciences (No. 2017YJJ23005)supported by Vietnam State-Level Project KC09.14/16-20
文摘The Beibu Gulf is at an important geographical location and rich in gas, oil and biological resources. The observed currents showed that the current in the upper layer was opposite to that in the lower layer in boreal winter in the northern Beibu Gulf and it was northeastward in the lower layer. This northeastward current was reproduced by a 3 D baroclinic model in this study. It's found that the counter-wind deep current(referred to as ‘CWDC' hereinafter) strengthened from September to November but weakened from December to the following February. A closed meridional circulation in vertical direction was found in the northern Beibu Gulf, including CWDC, surface southwestward current, an upwelling, and a downwelling. The temporal variation process of the meridional circulation was similar to that of CWDC, with strength and range stronger in November and December than in other four months. Similar to the variation process of CWDC, the monsoon wind changed from weak easterly wind in September to strong northeasterly wind in November and December, and it was transformed into weak southeasterly wind in February again. The sensitive experiments showed that CWDC and the meridional circulation were controlled by the monsoon wind and were adjusted by heat flux-and tide-induced mixing, respectively. According to the momentum balance equation, it can be revealed the counter-wind deep current is a compensation current which is induced by the surface elevation gradient balanced by the Coriolis force, vertical diffusion and baroclinic pressure gradient.
文摘With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.