The basic theory and effect of the new farming method of ＂Fenlong＂ cultivation which has been included in the main extension technology of Ministry of Agriculture of the People＇s Republic of China is fully illustra...The basic theory and effect of the new farming method of ＂Fenlong＂ cultivation which has been included in the main extension technology of Ministry of Agriculture of the People＇s Republic of China is fully illustrated for the first time, and it is the fourth set （generation） of farming modes and methods following manpower, animal and mechanical （tractor） farming. It follows the natural law to achieve soil activation, water saving, oxygen increase, warming and desalination through the active use of natural resources like soil, rainfall and solar energy, thereby promoting a new round of natural agricultural production and quality improvement and water con- servation, which has crop yield increase by 10%-30%, quality improvement of 5%, natural precipitation retaining increase by100%. The characteristics and mechanism are the use of spiral drill for one-time completion of the land preparation by drilling vertically to 30-50 cm of soil layer through high speed peeling. After instant high temperature and many fierce impacts, mechanical frictions, it could achieve the multiplication of the number of loose soil, soil physical modification and expansion of the soil nutrients, reservoirs, oxygen, microorganisms （＂Four pools＂）. Fenlong cultivation can give birth to new farming culture and civilization, and it can achieve the physical ＂desalinized＂ transformation and utilization of saline soil. The formation of Fenlong green farming technology system makes it possible to invent the farming tools of ＂serf-propelled Fenlong machinery＂ that has got the patent, and it is the method for farmland （dry land, paddy field） Fenlong cultivation, saline-alkali soil smash-ridging cultivation and for the abundance of grass ecology on degraded grassland. The application of Fenlong ＂4＋1＂ （arable, saline-alkali soil, grasslands, Sponge City＋rivers） green development in China can achieve the ＂double safety＂ of food and living space.展开更多
In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties ...In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties of tea garden soil were studied through the modification of the test sites with the non-farming land as the control. The results showed that human farming, mini-tiller farming and crawler tractor farming could improve the physical and chemical properties of soil. After farming, the soil had good water retention but low moisture content compared to the control group, while the soil bulk density and hardness value were significantly lower than those of the control, and the porosity of soil was significantly higher than that of contrast. With the passage of time, soil bulk density and hardness value gradually increased after farming, while the porosity of soil decreased gradually. There were great differences in the effects, efficiencies and costs of different farming methods. Crawler tractor had the best and most stable farming effect, and the operation efficiency was 10 times that of human farming while the cost was only 0.39 times of human farming. Therefore, it was feasible to adopt mini-tiller or crawler tractor to carry out mechanical farming of Guilin Maojian tea garden, which provided theoretical references for the soil property improvement using mechanical farming and was favorable for promoting the popularization of farming machines and the acceleration of mechanization of tea gardens. But for tea plantations that are intended to be mechanized, apart from the mechanical and technical personnel to be configured in place, the site conditions, planting modes and mechanical way reservation of tea garden should be planned accordingly. It is recommended to select flat or gentle slope for reclamation, and preference is given to non-sexual tea tree varieties with big line spacing over 180 cm long. Moreover, the main road construction should be more than 3.0 m, and trunk road 2.0 m or above. And isolation ditch and drain should be set between the tea garden and the surrounding mountain forests and farmland.展开更多
After expatiating the guiding ideology,contents,standards and principles of eco-environment restoration based on enlarging terrace and de-farming,this paper discussed the planning method and technical flow of enlargin...After expatiating the guiding ideology,contents,standards and principles of eco-environment restoration based on enlarging terrace and de-farming,this paper discussed the planning method and technical flow of enlarging terrace and garden plot in a small catchment of loess hilly region by means of GIS spatial analysis technology,and then the planning method was applied in Yangou catchment.The result showed that it is practicabl,and the areas of newly-built terrace and garden plot in Yangou catchment are at least 295.06 and 4.61 hm2,so that the areas of basic farmland and garden plot reach 359.23 and 622.69 hm2.After the land use structure is regulated,the forest coverage is 48.87%,and the permanent vegetation coverage is about 75% in Yangou catchment,while sediment reduction benefit is above 80% in slope land.In agricultural development,Yangou catchment can yield 1 645.13 tons of food supplies,above 9 340 tons of apples,and can feed 7 500 sheep every year.展开更多
Waste recovery is an environmental, agronomic and economic asset. The farm “Société de Provenderies du Cameroun” (SPC) processes its wastes by incineration and landfill. During this study, environmental im...Waste recovery is an environmental, agronomic and economic asset. The farm “Société de Provenderies du Cameroun” (SPC) processes its wastes by incineration and landfill. During this study, environmental impacts of these two treatment methods were assessed in this farm and a composting experiment was also conducted. For the experiment, chicken carcasses and droppings mixed with wood shavings, straw, incineration ash, egg shells and cattle dung were distributed differently in four experimental composters C1, C2, C3 and C4 with the same starting weight. C1 consisted of the first three waste types, for C2, C3 and C4 a new waste was added in the order they are listed above. The results show that the major impacts associated with the incineration and landfilling of SPC waste are the degradation of the health of workers and surrounding populations, the occurrence of conflicts, and the pollution of the air, soil and groundwater of the site. As far as composting is concerned, the characteristics of three of the four composts obtained are usable as soil fertilisers. Indeed, at the end of the experiment, the pH of the four composters was basic (8), the temperature values were between 24°C and 34°C and the humidity values were between 37% and 41%. However, the last parameter, the C/N ratio, was not satisfactory for C1 (13.42), which eliminated it from mature and ready-to-use composts according to FAO standards. The C/N ratios of C2 (15.71), C3 (16.30), and C4 (18) composters were found to be good for mature and ready-to-use compost.展开更多
The negative effects of traditional methods of electricity generation on the<span style="font-family:;" "=""><span style="font-family:Verdana;"> environment have created ...The negative effects of traditional methods of electricity generation on the<span style="font-family:;" "=""><span style="font-family:Verdana;"> environment have created the need for strategic planning and development of renewable and sustainable energy systems. This paper presents the analysis of the suitability of wind farm sites using a Boolean decision-making approach </span><span style="font-family:Verdana;">based on geographic information system (GIS) modeling. This analysis is </span><span style="font-family:Verdana;">based on different climatic, geographical, economic and environmental criteria such </span><span style="font-family:Verdana;">as wind resource, slope, accessibility by road, proximity to the electricity</span><span style="font-family:Verdana;"> network and optimal distance from airports. The results of the study show that the most favorable sites are mainly located in the northern part of the country, particularly in the Far North and North regions. There are also favorable </span><span style="font-family:Verdana;">sites in the North-West, South-West, West, Littoral and very little in the</span><span style="font-family:Verdana;"> South while the central and eastern regions are not suitable. This is mainly due to the tropical forest that covers the entire region of East Cameroon and the low wind speed in these regions which is the determining factor for the installation of wind farms. The appropriate land for the installation of wind </span><span style="font-family:Verdana;">farms is </span><span style="font-family:Verdana;">approximately 2.56% corresponding to an area of </span></span><span style="font-family:Verdana;">11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">602</span><span style="font-family:Verdana;">.494414</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">km<span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span><span style="font-family:Verdana;">. Ho</span><span style="font-family:Verdana;">w</span><span style="font-family:Verdana;">ever, when we include the condition that a wind farm must have at least 4</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">km<sup></sup></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;"> of surface area, is goes from 2.56% to 2.22% (11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">602.494414 km<sup></sup></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;"> to</span><span style="font-family:Verdana;"> 10</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;">344.424539 km</span><span style="font-family:Verdana;"><sup></sup></span></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;">);thus a surface reduction of approximately 1258</span><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""><span style="font-family:Verdana;">069875 km</span><span style="font-family:Verdana;"><sup></sup></span></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;">. We can conclude that despite the fact that Cameroon does not have a huge potential for wind energy because of the low wind speed observed in the country, it is still possible to have some favorable sites for the installation of the parks wind. In addition, a study of hybrid solar-wind systems could improve the efficiency of the power plants in Cameroon.</span>展开更多
大规模双馈风电场作为实现我国“双碳”目标的陆上风电主力,其高比例电力电子设备的接入对电力系统电磁暂态高精度仿真技术提出日益严苛的要求,面向上百台发电单元的双馈场站全拓扑精细化微秒级仿真研究仍相对空白。基于现场可编程门阵...大规模双馈风电场作为实现我国“双碳”目标的陆上风电主力,其高比例电力电子设备的接入对电力系统电磁暂态高精度仿真技术提出日益严苛的要求,面向上百台发电单元的双馈场站全拓扑精细化微秒级仿真研究仍相对空白。基于现场可编程门阵列(field programmable gate array,FPGA)微秒级小步长并行仿真能力,提出一种面向双馈风电场站的发电单元FPGA并行仿真方法。首先,进行双馈感应电机微秒级高并行度离散化建模与换流器受控源建模;接着,对节点导纳矩阵分块降维以实现发电单元内部分网并行,并从整体电路解算层面提出单元级并行仿真框架;最后,考虑实时数字仿真器(real time digital simulator,RTDS)与FPGA仿真平台特点,分配发电单元的微秒级小步长仿真任务并搭建联合仿真硬件框架;通过对比RTDS标准模型与RTDS+FPGA联合仿真模型,验证所提并行仿真方法的准确性。展开更多
基金Supported by the National Key Technology R&D Program of China(2014BAD06B05)the Major Project of Science and Technology of Guangxi(2017AA22015)~~
文摘The basic theory and effect of the new farming method of ＂Fenlong＂ cultivation which has been included in the main extension technology of Ministry of Agriculture of the People＇s Republic of China is fully illustrated for the first time, and it is the fourth set （generation） of farming modes and methods following manpower, animal and mechanical （tractor） farming. It follows the natural law to achieve soil activation, water saving, oxygen increase, warming and desalination through the active use of natural resources like soil, rainfall and solar energy, thereby promoting a new round of natural agricultural production and quality improvement and water con- servation, which has crop yield increase by 10%-30%, quality improvement of 5%, natural precipitation retaining increase by100%. The characteristics and mechanism are the use of spiral drill for one-time completion of the land preparation by drilling vertically to 30-50 cm of soil layer through high speed peeling. After instant high temperature and many fierce impacts, mechanical frictions, it could achieve the multiplication of the number of loose soil, soil physical modification and expansion of the soil nutrients, reservoirs, oxygen, microorganisms （＂Four pools＂）. Fenlong cultivation can give birth to new farming culture and civilization, and it can achieve the physical ＂desalinized＂ transformation and utilization of saline soil. The formation of Fenlong green farming technology system makes it possible to invent the farming tools of ＂serf-propelled Fenlong machinery＂ that has got the patent, and it is the method for farmland （dry land, paddy field） Fenlong cultivation, saline-alkali soil smash-ridging cultivation and for the abundance of grass ecology on degraded grassland. The application of Fenlong ＂4＋1＂ （arable, saline-alkali soil, grasslands, Sponge City＋rivers） green development in China can achieve the ＂double safety＂ of food and living space.
基金Supported by the Planned Project for Science and Technology Development of Guilin City,China(20150117-2)the Special Fund for the Basic Research Operating Expenses Program of Public Welfare Research Institute Directly Subordinate to Guangxi,China(GCJB-16-18)
文摘In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties of tea garden soil were studied through the modification of the test sites with the non-farming land as the control. The results showed that human farming, mini-tiller farming and crawler tractor farming could improve the physical and chemical properties of soil. After farming, the soil had good water retention but low moisture content compared to the control group, while the soil bulk density and hardness value were significantly lower than those of the control, and the porosity of soil was significantly higher than that of contrast. With the passage of time, soil bulk density and hardness value gradually increased after farming, while the porosity of soil decreased gradually. There were great differences in the effects, efficiencies and costs of different farming methods. Crawler tractor had the best and most stable farming effect, and the operation efficiency was 10 times that of human farming while the cost was only 0.39 times of human farming. Therefore, it was feasible to adopt mini-tiller or crawler tractor to carry out mechanical farming of Guilin Maojian tea garden, which provided theoretical references for the soil property improvement using mechanical farming and was favorable for promoting the popularization of farming machines and the acceleration of mechanization of tea gardens. But for tea plantations that are intended to be mechanized, apart from the mechanical and technical personnel to be configured in place, the site conditions, planting modes and mechanical way reservation of tea garden should be planned accordingly. It is recommended to select flat or gentle slope for reclamation, and preference is given to non-sexual tea tree varieties with big line spacing over 180 cm long. Moreover, the main road construction should be more than 3.0 m, and trunk road 2.0 m or above. And isolation ditch and drain should be set between the tea garden and the surrounding mountain forests and farmland.
基金Supported by National Natural Science Foundation of China(41171449)Key Project of Chinese Academy of Sciences(KZZD-EW-06-01)
文摘After expatiating the guiding ideology,contents,standards and principles of eco-environment restoration based on enlarging terrace and de-farming,this paper discussed the planning method and technical flow of enlarging terrace and garden plot in a small catchment of loess hilly region by means of GIS spatial analysis technology,and then the planning method was applied in Yangou catchment.The result showed that it is practicabl,and the areas of newly-built terrace and garden plot in Yangou catchment are at least 295.06 and 4.61 hm2,so that the areas of basic farmland and garden plot reach 359.23 and 622.69 hm2.After the land use structure is regulated,the forest coverage is 48.87%,and the permanent vegetation coverage is about 75% in Yangou catchment,while sediment reduction benefit is above 80% in slope land.In agricultural development,Yangou catchment can yield 1 645.13 tons of food supplies,above 9 340 tons of apples,and can feed 7 500 sheep every year.
文摘Waste recovery is an environmental, agronomic and economic asset. The farm “Société de Provenderies du Cameroun” (SPC) processes its wastes by incineration and landfill. During this study, environmental impacts of these two treatment methods were assessed in this farm and a composting experiment was also conducted. For the experiment, chicken carcasses and droppings mixed with wood shavings, straw, incineration ash, egg shells and cattle dung were distributed differently in four experimental composters C1, C2, C3 and C4 with the same starting weight. C1 consisted of the first three waste types, for C2, C3 and C4 a new waste was added in the order they are listed above. The results show that the major impacts associated with the incineration and landfilling of SPC waste are the degradation of the health of workers and surrounding populations, the occurrence of conflicts, and the pollution of the air, soil and groundwater of the site. As far as composting is concerned, the characteristics of three of the four composts obtained are usable as soil fertilisers. Indeed, at the end of the experiment, the pH of the four composters was basic (8), the temperature values were between 24°C and 34°C and the humidity values were between 37% and 41%. However, the last parameter, the C/N ratio, was not satisfactory for C1 (13.42), which eliminated it from mature and ready-to-use composts according to FAO standards. The C/N ratios of C2 (15.71), C3 (16.30), and C4 (18) composters were found to be good for mature and ready-to-use compost.
文摘The negative effects of traditional methods of electricity generation on the<span style="font-family:;" "=""><span style="font-family:Verdana;"> environment have created the need for strategic planning and development of renewable and sustainable energy systems. This paper presents the analysis of the suitability of wind farm sites using a Boolean decision-making approach </span><span style="font-family:Verdana;">based on geographic information system (GIS) modeling. This analysis is </span><span style="font-family:Verdana;">based on different climatic, geographical, economic and environmental criteria such </span><span style="font-family:Verdana;">as wind resource, slope, accessibility by road, proximity to the electricity</span><span style="font-family:Verdana;"> network and optimal distance from airports. The results of the study show that the most favorable sites are mainly located in the northern part of the country, particularly in the Far North and North regions. There are also favorable </span><span style="font-family:Verdana;">sites in the North-West, South-West, West, Littoral and very little in the</span><span style="font-family:Verdana;"> South while the central and eastern regions are not suitable. This is mainly due to the tropical forest that covers the entire region of East Cameroon and the low wind speed in these regions which is the determining factor for the installation of wind farms. The appropriate land for the installation of wind </span><span style="font-family:Verdana;">farms is </span><span style="font-family:Verdana;">approximately 2.56% corresponding to an area of </span></span><span style="font-family:Verdana;">11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">602</span><span style="font-family:Verdana;">.494414</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">km<span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span><span style="font-family:Verdana;">. Ho</span><span style="font-family:Verdana;">w</span><span style="font-family:Verdana;">ever, when we include the condition that a wind farm must have at least 4</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">km<sup></sup></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;"> of surface area, is goes from 2.56% to 2.22% (11</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">602.494414 km<sup></sup></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;"> to</span><span style="font-family:Verdana;"> 10</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;">344.424539 km</span><span style="font-family:Verdana;"><sup></sup></span></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;">);thus a surface reduction of approximately 1258</span><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""><span style="font-family:Verdana;">069875 km</span><span style="font-family:Verdana;"><sup></sup></span></span><span style="font-family:Verdana;"><span style="white-space:normal;font-family:Verdana;"><span style="white-space:nowrap;"><sup></sup></span><sup></sup></span><span style="white-space:normal;font-family:Verdana;"><sup>2</sup><span style="white-space:nowrap;"></span></span></span><span style="font-family:Verdana;">. We can conclude that despite the fact that Cameroon does not have a huge potential for wind energy because of the low wind speed observed in the country, it is still possible to have some favorable sites for the installation of the parks wind. In addition, a study of hybrid solar-wind systems could improve the efficiency of the power plants in Cameroon.</span>
文摘大规模双馈风电场作为实现我国“双碳”目标的陆上风电主力,其高比例电力电子设备的接入对电力系统电磁暂态高精度仿真技术提出日益严苛的要求,面向上百台发电单元的双馈场站全拓扑精细化微秒级仿真研究仍相对空白。基于现场可编程门阵列(field programmable gate array,FPGA)微秒级小步长并行仿真能力,提出一种面向双馈风电场站的发电单元FPGA并行仿真方法。首先,进行双馈感应电机微秒级高并行度离散化建模与换流器受控源建模;接着,对节点导纳矩阵分块降维以实现发电单元内部分网并行,并从整体电路解算层面提出单元级并行仿真框架;最后,考虑实时数字仿真器(real time digital simulator,RTDS)与FPGA仿真平台特点,分配发电单元的微秒级小步长仿真任务并搭建联合仿真硬件框架;通过对比RTDS标准模型与RTDS+FPGA联合仿真模型,验证所提并行仿真方法的准确性。
