Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UF...Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.展开更多
This paper describes the unique in-land, non-Nilotic delta of Wadi El Galla, a seasonal water course which originates in the Nuba Mountains of Kordofan region and terminates in a chain of small ponds each known locall...This paper describes the unique in-land, non-Nilotic delta of Wadi El Galla, a seasonal water course which originates in the Nuba Mountains of Kordofan region and terminates in a chain of small ponds each known locally as a Bouta (pl Bowati). The Bowati are inhabited by a community of aquatic plants forming a wide spectrum ranging from small true (Euophytes) to large woody trees. The euophytes encountered were grouped into six categories. The free-floating species were represented by the small <i>Lemna purpusilla</i> Torr. and the larger <i>Pistia stratiotes</i> L. while only one submerged species was found: <i>Ottelia alismoides</i> (Planch.) Welp. One suspended species was found, <i>Utricularia stellaris</i> L. F. Three species of the floating-leaved plants were encountered namely, <i>Nymphaea lotus</i> L., <i>N. micrantha</i> Guill. & Perrott and <i>Nymphoides nilotica</i> (Kotschy & Peyr.) Léonard. The emergent <i>Limnophyton obtusifolium</i> (L.) Miq. was very prominent in all the Bowat constituting with N. lotus the two dominant species. Trailing from the Bouta edge and forming thick mats on the open water is <i>Neptunia oleracea</i> Lour., a member of the Fabaceae family. Within these euophytes and towering to over ten meters is the woody tree <i>Mitragyna inermis</i> Kuntze. Some of herbaceous plants are a source of food for the local community such as the bulbils of <i>Nymphaea micrantha</i>. These meagrely studied ecosystems are under threat from natural and anthropogenic factors. The former are the recurrent drought, climate change, and the latter are due to urbanization, overexploitation and oil activities. There is an urgent need for delineating and mapping the geomorphology, drainage patterns of Al Muglad in-land delta as well as the number and sites of the Bowati. The taxonomy of the aquatic species, their nutritive and medicinal values are other areas of research. Within such a context, a concerted national and international endeavour is called for to conserve these unique ecosystems and conceivably, declaring them as protected sites.展开更多
针对舰载机安全着舰对高精度、高可靠性着舰导引系统的迫切需求,研究了卫星/伪卫星/惯性组合着舰导引技术,基于几何精度因子(geometric dilution of precision,GDOP)计算提出了伪卫星在舰船上的布设方案,并设计了其导航电文结构。研究...针对舰载机安全着舰对高精度、高可靠性着舰导引系统的迫切需求,研究了卫星/伪卫星/惯性组合着舰导引技术,基于几何精度因子(geometric dilution of precision,GDOP)计算提出了伪卫星在舰船上的布设方案,并设计了其导航电文结构。研究了卫星/伪卫星/惯性组合着舰导引算法,利用卫星及伪卫星的双差分载波相位信息,采用改进的模糊度最小二乘去相关平差(least-squares ambiguity decorrelation adjustment,LAMBDA)迭代算法解算其双差分整周模糊度,并基于舰载机运动模型建立滤波方程解算出舰机相对运动信息,再与惯导数据进行信息融合得到高精度的导引信息。仿真结果表明,提出的卫星/伪卫星/惯性着舰导引技术横向定位误差在0.3m以内,纵向定位误差在0.1m以内,高度定位误差在0.3m以内,可以满足舰载机着舰的要求,与卫星/惯性组合导引相比,该组合方式大大提高了垂直方向的定位精度,这对于确保安全着舰极为重要。并且,提出的着舰导引技术不仅精度高,而且工作连续可靠、抗干扰能力强,对保障舰载机着舰安全有重要的意义。展开更多
In this paper, Nanogrid System and working is presented for the future sustainable power system. This system is for small scale for smart homes with decentralized power system. A Nanogrid is the combination of energy ...In this paper, Nanogrid System and working is presented for the future sustainable power system. This system is for small scale for smart homes with decentralized power system. A Nanogrid is the combination of energy system such as using of sources such as solar cells, fuel cells, micro turbines, wind turbines, energy storage devices and AC, DC power systems and controllable loads. This grid may use single mode or island mode with soft switching. The Dynamic of power system capability increases reliability, in case if one system fails it switch to other system to continue proving electric power with losing quality. The energy storage system is used to maintain stability during transition between the operating modes is emphasized. The Simulink model is used to present the working of system.展开更多
The role of the Trans-Siberian main railway is considered related to interaction between the West and the East of Eurasia. The stages of formation of a transport-economic belt along the Trans-Siberian main railway and...The role of the Trans-Siberian main railway is considered related to interaction between the West and the East of Eurasia. The stages of formation of a transport-economic belt along the Trans-Siberian main railway and its branches are distinguished. The main features of long-term development of the Trans-Siberian main railway, its new branches, and also the Russian mega project ＂Integrated Eurasian infrastructural system＂ are presented. The comparative characteristic of a zone of influence of the Trans-Siberian main railway and a New Silk Road in the People＇s Republic of China is given. General environmental issues in the development of transcontinental Eur- asian transport-economic belts are singled out. The authors believe that despite some competition to the Trans-Si- berian Main Railway in the Eurasian transport transit, realization of the New Silk Road project will bring obvious so- cio-economic and environmental benefits for participating countries through formation of the zone of the sustainable development along this transport corridor. Finally, it will undoubtedly contribute to achievement of closer economic integration and greater security in Eurasia.展开更多
文摘Maritime transportation, widely used both in international transport of goods and touristic purposes, has been identified as a significant source of ultrafine particles (UFP). In-land passenger ferry is a source of UFP far less addressed;however, in locations with relatively high frequency of this transportation mode, it is expected that they contribute to an increase of their concentration. Moreover, the negative effects of UFP on human health and environment are known and therefore, monitoring UFP produced by ferries is vital to assess the degree of exposure of who work or live close to ferries’ terminals or downwind to their cruising path. This work aims to study the influence of in-land ferries activities on UFP in the urban/suburban areas near ferries’ terminals and downwind across the cruising path. The UFP monitoring campaign was carried out from September to December 2018 for 19 non-consecutive periods. The sampling sites were chosen in order to maximize measurements under downwind conditions and allow the association between ferry operation and UFP concentration response. Based on data collected, correlation analysis was performed between ferry’s traffic and particle number counting (PNC) of UFP, and also with meteorological variables. Results show an increase in PNC ranging from 25 to 197% during the third minute around a ferry movement and are moderate to positive significant correlations between PNC values and the number of ferry operations (r = 0.79 to r = 0.94), showing that UFP emitted by in-land ferries contributes to PNC increase. Moreover, negative correlations (r = -0.85 to r = -0.93) between PNC and wind intensity were also found.
文摘This paper describes the unique in-land, non-Nilotic delta of Wadi El Galla, a seasonal water course which originates in the Nuba Mountains of Kordofan region and terminates in a chain of small ponds each known locally as a Bouta (pl Bowati). The Bowati are inhabited by a community of aquatic plants forming a wide spectrum ranging from small true (Euophytes) to large woody trees. The euophytes encountered were grouped into six categories. The free-floating species were represented by the small <i>Lemna purpusilla</i> Torr. and the larger <i>Pistia stratiotes</i> L. while only one submerged species was found: <i>Ottelia alismoides</i> (Planch.) Welp. One suspended species was found, <i>Utricularia stellaris</i> L. F. Three species of the floating-leaved plants were encountered namely, <i>Nymphaea lotus</i> L., <i>N. micrantha</i> Guill. & Perrott and <i>Nymphoides nilotica</i> (Kotschy & Peyr.) Léonard. The emergent <i>Limnophyton obtusifolium</i> (L.) Miq. was very prominent in all the Bowat constituting with N. lotus the two dominant species. Trailing from the Bouta edge and forming thick mats on the open water is <i>Neptunia oleracea</i> Lour., a member of the Fabaceae family. Within these euophytes and towering to over ten meters is the woody tree <i>Mitragyna inermis</i> Kuntze. Some of herbaceous plants are a source of food for the local community such as the bulbils of <i>Nymphaea micrantha</i>. These meagrely studied ecosystems are under threat from natural and anthropogenic factors. The former are the recurrent drought, climate change, and the latter are due to urbanization, overexploitation and oil activities. There is an urgent need for delineating and mapping the geomorphology, drainage patterns of Al Muglad in-land delta as well as the number and sites of the Bowati. The taxonomy of the aquatic species, their nutritive and medicinal values are other areas of research. Within such a context, a concerted national and international endeavour is called for to conserve these unique ecosystems and conceivably, declaring them as protected sites.
文摘In this paper, Nanogrid System and working is presented for the future sustainable power system. This system is for small scale for smart homes with decentralized power system. A Nanogrid is the combination of energy system such as using of sources such as solar cells, fuel cells, micro turbines, wind turbines, energy storage devices and AC, DC power systems and controllable loads. This grid may use single mode or island mode with soft switching. The Dynamic of power system capability increases reliability, in case if one system fails it switch to other system to continue proving electric power with losing quality. The energy storage system is used to maintain stability during transition between the operating modes is emphasized. The Simulink model is used to present the working of system.
基金National Natural Science Foundation of China(4127155641101117)+1 种基金National Natural Science Foundation of China and Russian Foundation for Basic Research(414110106515-56-53037)
文摘The role of the Trans-Siberian main railway is considered related to interaction between the West and the East of Eurasia. The stages of formation of a transport-economic belt along the Trans-Siberian main railway and its branches are distinguished. The main features of long-term development of the Trans-Siberian main railway, its new branches, and also the Russian mega project ＂Integrated Eurasian infrastructural system＂ are presented. The comparative characteristic of a zone of influence of the Trans-Siberian main railway and a New Silk Road in the People＇s Republic of China is given. General environmental issues in the development of transcontinental Eur- asian transport-economic belts are singled out. The authors believe that despite some competition to the Trans-Si- berian Main Railway in the Eurasian transport transit, realization of the New Silk Road project will bring obvious so- cio-economic and environmental benefits for participating countries through formation of the zone of the sustainable development along this transport corridor. Finally, it will undoubtedly contribute to achievement of closer economic integration and greater security in Eurasia.
