muscle: chemistry of contraction - part 24 of 26. what part of the muscle contracts and what triggers the contraction? with the aid of an electron microscope and a simple tabletop model of muscle filaments, dr. georges r. marchal, universit de louvan, - 磁場 個影片檔及 b 捲影像00:28人體構造
magnetic, electric and gravitational fields - part 9 of 19. evidence of the magnetic field is illustrated by bringing a compass close to a magnet and watching the compass needle. further evidence of an electric field is demonstrated by rubbing a plastic r - 磁場 個影片檔及 b 捲影像00:37
magnetic, electric and gravitational fields - part 8 of 19. evidence of the magnetic field is illustrated by bringing a compass close to a magnet and watching the compass needle. further evidence of an electric field is demonstrated by rubbing a plastic r - 磁場 個影片檔及 b 捲影像00:33
magnetic, electric and gravitational fields - part 1 of 19. evidence of the magnetic field is illustrated by bringing a compass close to a magnet and watching the compass needle. further evidence of an electric field is demonstrated by rubbing a plastic r - 磁場 個影片檔及 b 捲影像00:24
space probes - exploring our solar system - part 17 of 18. animation, live photography, and models of spacecraft and instruments tell the story of man's efforts to explore the outer regions of space - from the launching of pioneer i in 1958 to present-day - 磁場 個影片檔及 b 捲影像00:26外太空
electric motor. this consists of a loop of wire that is free to rotate in a magnetic field (yellow arrows). - 磁場 個影片檔及 b 捲影像00:20
the solar or sun activity during the whole 2015 year (time lapse, part of a series) - 磁場 個影片檔及 b 捲影像00:43
the solar or sun activity during the whole 2015 year (time lapse, part of a series) - 磁場 個影片檔及 b 捲影像00:44
the solar or sun activity during the whole 2015 year (time lapse, part of a series) - 磁場 個影片檔及 b 捲影像00:42
the solar or sun activity during the whole 2015 year (time lapse, part of a series) - 磁場 個影片檔及 b 捲影像00:42
