为精准控制剖面浮标的垂向运动,提出一种可精确控制油量的变体积油囊式浮力调节系统,包含外油囊、增压油箱、密封性能良好的电磁球阀和可调节转速的液压泵等组件。采用拉线位移传感器实时采集增压油箱液面位置实现油量监控,并对外油囊...为精准控制剖面浮标的垂向运动,提出一种可精确控制油量的变体积油囊式浮力调节系统,包含外油囊、增压油箱、密封性能良好的电磁球阀和可调节转速的液压泵等组件。采用拉线位移传感器实时采集增压油箱液面位置实现油量监控,并对外油囊体积进行高精度闭环反馈控制;设计极低泄漏量的液压系统,实现系统在待机状态下浮力保持长期稳定。为精确控制浮力调节系统,构建控制系统数学模型,引入比例积分微分(Proportional Integral Differential,PID)控制算法,并采用Simulink进行稳定性仿真。试验结果表明,系统可实现浮力精确控制,最大超调量低于1%,稳定性与响应速度均符合预期,验证了控制策略的可靠性。展开更多
The methane concentration of water samples at five stations collected by the CTD rosette water sampler in the areas of southwest Dongsha Islands and the Xisha Trough was analyzed by the gas-stripping method on aboard ...The methane concentration of water samples at five stations collected by the CTD rosette water sampler in the areas of southwest Dongsha Islands and the Xisha Trough was analyzed by the gas-stripping method on aboard ship. It shows abnormal high methane concentrations in near bottom water samples at three stations. In the southwest Dongsha Islands area, the methane concentration of 4.25 and 10.64 nmol/dm3 occurs in near bottom water samples at Stas E105A and E106, respectively. In the Xisha Trough area, the high methane concentrations of 5.17, 8.48 and 8.70 nmol/dm3 in water depths of 1 750, 1 900 and 2 050 m, respectively, have been observed at Sta. E413. It is believed that the abnormal high methane concentrations are generated from the leakage of methane from sediments. Combining with previous geophysical and geochemical data from these two areas, this was probably related to the submarine gas hydrates decomposition and cold seep system. In May 2007, gas hydrate samples were successfully obtained by the drilling in the Shenhu Sea area located in the southwest Dongsha Islands area. It is called for further drilling surveys to confirm the existence of gas hydrate and cold seep system in the Xisha Trough as early as possible.展开更多
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...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
[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(...[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(i.e.decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,decomposed organic fertilizer+compound fertilizer)were designed to determine the changes in physical and chemical properties before and after soil treatment,and the survival rate,plant height and ground diameter of four different cultivated plants within one year,and the effects of applying biochemical fulvic acid potassium on cultivated plants were investigated.[Result]The soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,soil available phosphorus,soil available potassium and p H value in the soil treated with decomposed organic fertilizer+biochemical fulvic acid potassium soluble fertilizer,and decomposed organic fertilizer+compound fertilizer increased significantly,and the soil bulk density decreased obviously.The survival rates,plant heights and ground diameters of four different cultivated plants were significantly improved after application of decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,and decomposed organic fer-tilizer+compound fertilizer(P<0.05).[Conclusion]The application of biochemical fulvic acid potassium on cultivated plants effectively improved soil fertility,increased the utilization of nitrogen,phosphorus and potassium,improved the growth of plants,and promoted the growth of landscaping plants after transplantation.展开更多
[Objective] The paper was to analyze the meteorological epidemic factors for occurrence and prevalence of tobacco bacterial wilt( Ralstonia solanacarum),and to study control effects of different soil conditioners on t...[Objective] The paper was to analyze the meteorological epidemic factors for occurrence and prevalence of tobacco bacterial wilt( Ralstonia solanacarum),and to study control effects of different soil conditioners on the bacterial disease in Gaoligongshan demonstration area of green,ecological,high quality tobacco leaf production. [Method] The plots attacked by tobacco bacterial wilt over the years were selected and the incidence of the disease was periodically surveyed in tobacco growth period in 2012,2103 and 2014,respectively. 10 d Effective accumulated temperature and rainfall were counted according to the meteorological data,and the relationship between meteorological factors and disease index was analyzed. The control effects of three kinds of soil conditioners " Zhuanggenfeng",refined fulvic acid and lime on tobacco bacterial wilt were tested. [Result] The analysis results of meteorological factors showed that 10 d effective accumulated temperature and rainfall were positively correlated to disease index. The variation curve of 10 d effective accumulated temperature and rainfall reflected the change trend of disease index. The p H values were increased by 0. 57,0. 50 and 0. 72 respectively after applying " Zhuanggenfeng",refined fulvic acid and lime. The average control effects on tobacco bacterial wilt were 60. 74%-62. 18%,53. 05%-59. 53%,and 48. 59%-58. 53%,respectively. [Conclusion] 10 d Effective accumulated temperature and rainfall could be used as important reference for disease forecasting and controlling. The usage of soil conditioner has a certain prevention and control effect on tobacco bacterial wilt disease by forming soil conditions conducive to flue-cured tobacco growth but adverse to disease survival,which is an effective auxiliary method against the disease.展开更多
The CDE hydrothermal field was first discovered during a Chinese cruise to the East Lau Basin Spreading Centre in 2007.Apart from significant amounts of loose Fe-Si-Mn(oxyhydr) oxide(referred to as oxide below) precip...The CDE hydrothermal field was first discovered during a Chinese cruise to the East Lau Basin Spreading Centre in 2007.Apart from significant amounts of loose Fe-Si-Mn(oxyhydr) oxide(referred to as oxide below) precipitates,a small Si-rich oxide chimney was also recovered on this cruise.In this study,we report on the mineralogical and geochemical analyses of this chimney and a model for its growth that has been developed.Based on the mineralogy and O isotope results,the chimney walls can be divided into four growth generations(layers) from the inner to the outer layers:amorphous opal and barite layer(precipitation temperature 68.5°C based on oxygen isotope determinations),a rod-like amorphous layer(precipitation temperature 39.6°C),a filamentous Fe-Si oxide layer,and an outer Fe-Mn oxide layer.Investigations based on SEM and EDS showed that neutrophilic Fe-oxidizing bacteria play an important role in the formation of this chimney,particularly in the outer two generations.In the first stage,the metabolic activity of the microbes results in the pervasive precipitation of the filamentous Fe-rich oxides inside a ring formed by some amorphous opal and barite;therefore,a loose porous layer forms.In the second stage,amorphous opal then precipitates inside this wall as a result of conductive cooling and gradually controls the mixing between the hydrothermal fluids and ambient seawaters.In the third stage,barite and some amorphous opal form from the higher temperature fluids at the summit of the chimney growth history.In the last stage,the chimney wall becomes thicker and denser and the exchange of hydrothermal fluids and seawater ceases.As a result,a Fe-Mn oxide layer precipitates onto the outer surface of the chimney wall as neutrophilic Fe-oxidizing bacteria reoccupy the surface of the chimney.This mineral sequence and the resultant growth generations are confirmed by the chemical characteristics of the chimney wall.Sr isotopes extracted from the Fe oxides of the four-generation wall generally show a decreasing trend of the 87 Sr/86 Sr ratios from the second layer to the inner layer(from 0.707008 to 0.705877) except for the outer layer(0.706502).The Sr isotope and chondrite normalized REE patterns of the corresponding bulk samples from the chimney wall also display a similar trend.Our study shows that the biogenic filament network plays a key role in the formation of the chimney in contrast to previous growth models of higher temperature chimneys,which often ignore the influence of biogenic factors.展开更多
文摘为精准控制剖面浮标的垂向运动,提出一种可精确控制油量的变体积油囊式浮力调节系统,包含外油囊、增压油箱、密封性能良好的电磁球阀和可调节转速的液压泵等组件。采用拉线位移传感器实时采集增压油箱液面位置实现油量监控,并对外油囊体积进行高精度闭环反馈控制;设计极低泄漏量的液压系统,实现系统在待机状态下浮力保持长期稳定。为精确控制浮力调节系统,构建控制系统数学模型,引入比例积分微分(Proportional Integral Differential,PID)控制算法,并采用Simulink进行稳定性仿真。试验结果表明,系统可实现浮力精确控制,最大超调量低于1%,稳定性与响应速度均符合预期,验证了控制策略的可靠性。
基金The National "863" High Technology Research Foundation of China under contract No.2006AA09Z222the Fujian Province Natural Science Foundation of China under contract No.2005YZ1013
文摘The methane concentration of water samples at five stations collected by the CTD rosette water sampler in the areas of southwest Dongsha Islands and the Xisha Trough was analyzed by the gas-stripping method on aboard ship. It shows abnormal high methane concentrations in near bottom water samples at three stations. In the southwest Dongsha Islands area, the methane concentration of 4.25 and 10.64 nmol/dm3 occurs in near bottom water samples at Stas E105A and E106, respectively. In the Xisha Trough area, the high methane concentrations of 5.17, 8.48 and 8.70 nmol/dm3 in water depths of 1 750, 1 900 and 2 050 m, respectively, have been observed at Sta. E413. It is believed that the abnormal high methane concentrations are generated from the leakage of methane from sediments. Combining with previous geophysical and geochemical data from these two areas, this was probably related to the submarine gas hydrates decomposition and cold seep system. In May 2007, gas hydrate samples were successfully obtained by the drilling in the Shenhu Sea area located in the southwest Dongsha Islands area. It is called for further drilling surveys to confirm the existence of gas hydrate and cold seep system in the Xisha Trough as early as possible.
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.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201503119-03-02)。
文摘[Objective]The paper was to clarify the application of biochemical fulvic acid potassium on the survival rate and growth of various trees transplanted in the process of landscaping.[Method]Two experimental treatments(i.e.decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,decomposed organic fertilizer+compound fertilizer)were designed to determine the changes in physical and chemical properties before and after soil treatment,and the survival rate,plant height and ground diameter of four different cultivated plants within one year,and the effects of applying biochemical fulvic acid potassium on cultivated plants were investigated.[Result]The soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,soil available phosphorus,soil available potassium and p H value in the soil treated with decomposed organic fertilizer+biochemical fulvic acid potassium soluble fertilizer,and decomposed organic fertilizer+compound fertilizer increased significantly,and the soil bulk density decreased obviously.The survival rates,plant heights and ground diameters of four different cultivated plants were significantly improved after application of decomposed organic fertilizer+biochemical fulvic acid potassium water soluble fertilizer,and decomposed organic fer-tilizer+compound fertilizer(P<0.05).[Conclusion]The application of biochemical fulvic acid potassium on cultivated plants effectively improved soil fertility,increased the utilization of nitrogen,phosphorus and potassium,improved the growth of plants,and promoted the growth of landscaping plants after transplantation.
基金Supported by Key Science and Technology Project of China National Tobacco Corporation(110201202015)Science and Technology Project of Yunnan Tobacco Company(2012YN11)
文摘[Objective] The paper was to analyze the meteorological epidemic factors for occurrence and prevalence of tobacco bacterial wilt( Ralstonia solanacarum),and to study control effects of different soil conditioners on the bacterial disease in Gaoligongshan demonstration area of green,ecological,high quality tobacco leaf production. [Method] The plots attacked by tobacco bacterial wilt over the years were selected and the incidence of the disease was periodically surveyed in tobacco growth period in 2012,2103 and 2014,respectively. 10 d Effective accumulated temperature and rainfall were counted according to the meteorological data,and the relationship between meteorological factors and disease index was analyzed. The control effects of three kinds of soil conditioners " Zhuanggenfeng",refined fulvic acid and lime on tobacco bacterial wilt were tested. [Result] The analysis results of meteorological factors showed that 10 d effective accumulated temperature and rainfall were positively correlated to disease index. The variation curve of 10 d effective accumulated temperature and rainfall reflected the change trend of disease index. The p H values were increased by 0. 57,0. 50 and 0. 72 respectively after applying " Zhuanggenfeng",refined fulvic acid and lime. The average control effects on tobacco bacterial wilt were 60. 74%-62. 18%,53. 05%-59. 53%,and 48. 59%-58. 53%,respectively. [Conclusion] 10 d Effective accumulated temperature and rainfall could be used as important reference for disease forecasting and controlling. The usage of soil conditioner has a certain prevention and control effect on tobacco bacterial wilt disease by forming soil conditions conducive to flue-cured tobacco growth but adverse to disease survival,which is an effective auxiliary method against the disease.
基金supported by National Natural Science Foundation of China(Grant Nos.40976045,40976025 and 41006072)
文摘The CDE hydrothermal field was first discovered during a Chinese cruise to the East Lau Basin Spreading Centre in 2007.Apart from significant amounts of loose Fe-Si-Mn(oxyhydr) oxide(referred to as oxide below) precipitates,a small Si-rich oxide chimney was also recovered on this cruise.In this study,we report on the mineralogical and geochemical analyses of this chimney and a model for its growth that has been developed.Based on the mineralogy and O isotope results,the chimney walls can be divided into four growth generations(layers) from the inner to the outer layers:amorphous opal and barite layer(precipitation temperature 68.5°C based on oxygen isotope determinations),a rod-like amorphous layer(precipitation temperature 39.6°C),a filamentous Fe-Si oxide layer,and an outer Fe-Mn oxide layer.Investigations based on SEM and EDS showed that neutrophilic Fe-oxidizing bacteria play an important role in the formation of this chimney,particularly in the outer two generations.In the first stage,the metabolic activity of the microbes results in the pervasive precipitation of the filamentous Fe-rich oxides inside a ring formed by some amorphous opal and barite;therefore,a loose porous layer forms.In the second stage,amorphous opal then precipitates inside this wall as a result of conductive cooling and gradually controls the mixing between the hydrothermal fluids and ambient seawaters.In the third stage,barite and some amorphous opal form from the higher temperature fluids at the summit of the chimney growth history.In the last stage,the chimney wall becomes thicker and denser and the exchange of hydrothermal fluids and seawater ceases.As a result,a Fe-Mn oxide layer precipitates onto the outer surface of the chimney wall as neutrophilic Fe-oxidizing bacteria reoccupy the surface of the chimney.This mineral sequence and the resultant growth generations are confirmed by the chemical characteristics of the chimney wall.Sr isotopes extracted from the Fe oxides of the four-generation wall generally show a decreasing trend of the 87 Sr/86 Sr ratios from the second layer to the inner layer(from 0.707008 to 0.705877) except for the outer layer(0.706502).The Sr isotope and chondrite normalized REE patterns of the corresponding bulk samples from the chimney wall also display a similar trend.Our study shows that the biogenic filament network plays a key role in the formation of the chimney in contrast to previous growth models of higher temperature chimneys,which often ignore the influence of biogenic factors.