The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculation...The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculations and numerical analysis for the microstrip patch antennas. In this paper, two different designs have been modelled and analyzed and both designs are based on the rectangular patches. The feeding point of one design is inside the patch while the other design contains feeding point outside the patch is T shaped. The computational analysis showed some interesting results for radiation pattern and far field domain. For these designs, the characteristic impedance taken is 50 Ω and the operating frequency domain is 1.4 to 1.7 GHz. The microstrip patch antennas are encapsulated in the inert spherical atmosphere of 20 mm thickness containing air inside it.展开更多
The far side of the moon is a unique place for some scientific investigations.Chang'e 4 is a Chinese lunar far side landing exploration mission.Relay communication satellite,named as Queqiao,is an important and in...The far side of the moon is a unique place for some scientific investigations.Chang'e 4 is a Chinese lunar far side landing exploration mission.Relay communication satellite,named as Queqiao,is an important and innovative part of Chang'e 4 mission.It can provide relay communication to the lander and the rover operating on the lunar far side to maintain their contacts with Earth.It was launched by LM-4C launch vehicle at the Xichang Satellite Launch Center on May 21,2018.After five precise orbit controls and a journey of more than 20 days,Queqiao inserted into final halo mission orbit around Earth-moon libration point 2,located about 65,000 km beyond the moon.It is the world's first communication satellite operating in that orbit.Up to now,Queqiao worked very well and provided reliable,continuous communication relay service for the lander and the rover to ensure the mission success of Chang'e 4 exploration mission.Via Queqiao,the lander and the rover were controlled to work by ground stations and obtained a great amount of scientific data.The mission overview,operation orbit selection,relay communication system design and flight profile were introduced in this article.展开更多
A marine outfall is a long pipeline that continuously discharges large amounts of effluent streams into the sea. As the number of marine outfalls along the coastal areas is growing, a far field mathematical model with...A marine outfall is a long pipeline that continuously discharges large amounts of effluent streams into the sea. As the number of marine outfalls along the coastal areas is growing, a far field mathematical model with two point sources on a sloping beach is used to assess the coastal water quality following discharges from two outfalls. Asymptotic approximation will be made to the concentration at the beach to measure how well the effluent plumes are mixed and diluted in the coastal waters. The result found agrees with the engineering practice of installing a two-port diffuser at the end of a single outfall to minimize its potential environment impacts.展开更多
文摘The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculations and numerical analysis for the microstrip patch antennas. In this paper, two different designs have been modelled and analyzed and both designs are based on the rectangular patches. The feeding point of one design is inside the patch while the other design contains feeding point outside the patch is T shaped. The computational analysis showed some interesting results for radiation pattern and far field domain. For these designs, the characteristic impedance taken is 50 Ω and the operating frequency domain is 1.4 to 1.7 GHz. The microstrip patch antennas are encapsulated in the inert spherical atmosphere of 20 mm thickness containing air inside it.
文摘The far side of the moon is a unique place for some scientific investigations.Chang'e 4 is a Chinese lunar far side landing exploration mission.Relay communication satellite,named as Queqiao,is an important and innovative part of Chang'e 4 mission.It can provide relay communication to the lander and the rover operating on the lunar far side to maintain their contacts with Earth.It was launched by LM-4C launch vehicle at the Xichang Satellite Launch Center on May 21,2018.After five precise orbit controls and a journey of more than 20 days,Queqiao inserted into final halo mission orbit around Earth-moon libration point 2,located about 65,000 km beyond the moon.It is the world's first communication satellite operating in that orbit.Up to now,Queqiao worked very well and provided reliable,continuous communication relay service for the lander and the rover to ensure the mission success of Chang'e 4 exploration mission.Via Queqiao,the lander and the rover were controlled to work by ground stations and obtained a great amount of scientific data.The mission overview,operation orbit selection,relay communication system design and flight profile were introduced in this article.
文摘A marine outfall is a long pipeline that continuously discharges large amounts of effluent streams into the sea. As the number of marine outfalls along the coastal areas is growing, a far field mathematical model with two point sources on a sloping beach is used to assess the coastal water quality following discharges from two outfalls. Asymptotic approximation will be made to the concentration at the beach to measure how well the effluent plumes are mixed and diluted in the coastal waters. The result found agrees with the engineering practice of installing a two-port diffuser at the end of a single outfall to minimize its potential environment impacts.
