The geomagnetic field affects all living organisms on the Earth.In this study we investigated the developmental and behavioral effects of rearing Mythimna separata in a near-zero magnetic field(<500 n T)compared to...The geomagnetic field affects all living organisms on the Earth.In this study we investigated the developmental and behavioral effects of rearing Mythimna separata in a near-zero magnetic field(<500 n T)compared to the local geomagnetic field(approximately 50μT).The near-zero magnetic field produced by a Helmholtz coil system significantly lengthened larval and pupal development durations,increased male longevity,and reduced pupal weight,female reproduction,and the relative expression level of the vitellogenin(Vg)gene in newly emerged females.Moreover,the near-zero magnetic field had a considerable negative effect on the mating ratio of M.separata adults.In addition,the moths in the near-zero magnetic field displayed less flight activity late in the night than those in the Earth's normal geomagnetic field,indicating that the flight rhythm of M.separata may be affected by the near-zero magnetic field.Reduction in magnetic field intensity may have negative effects on the development and flight of oriental armyworm,with consequent additional effects on its migration.展开更多
By the analysis of roller gear processing technology, combining with gear meshing mechanism and motion relationship, models for rolling gear machining parameter and zero-programming are established. In this paper, the...By the analysis of roller gear processing technology, combining with gear meshing mechanism and motion relationship, models for rolling gear machining parameter and zero-programming are established. In this paper, the automatic generation technology of NC program for CNC gear machining process has been studied and the zero-programming system architecture of open CNC gear-hobbing machine has been presented. In the design and development of the system, human computer interaction, programming algorithm and the design of each function module have bean done. Application test shows that the expected design requirements have been achieved.展开更多
基金the earmarked fund for China Agriculture Research System(CARS-22)the National Key Research and Development Program of China(2017YFD0201802 and 2017YFD0201701)+1 种基金the National Natural Science Foundation of China(31672019,31870367 and 31871951)the Beijing Municipal Natural Science Foundation,China(6172030)。
文摘The geomagnetic field affects all living organisms on the Earth.In this study we investigated the developmental and behavioral effects of rearing Mythimna separata in a near-zero magnetic field(<500 n T)compared to the local geomagnetic field(approximately 50μT).The near-zero magnetic field produced by a Helmholtz coil system significantly lengthened larval and pupal development durations,increased male longevity,and reduced pupal weight,female reproduction,and the relative expression level of the vitellogenin(Vg)gene in newly emerged females.Moreover,the near-zero magnetic field had a considerable negative effect on the mating ratio of M.separata adults.In addition,the moths in the near-zero magnetic field displayed less flight activity late in the night than those in the Earth's normal geomagnetic field,indicating that the flight rhythm of M.separata may be affected by the near-zero magnetic field.Reduction in magnetic field intensity may have negative effects on the development and flight of oriental armyworm,with consequent additional effects on its migration.
基金supported by the Natural Science Foundation of Sichuan Province Education Department(16ZB0551)College enterprise cooperation research project(ybzysc14-10)
文摘By the analysis of roller gear processing technology, combining with gear meshing mechanism and motion relationship, models for rolling gear machining parameter and zero-programming are established. In this paper, the automatic generation technology of NC program for CNC gear machining process has been studied and the zero-programming system architecture of open CNC gear-hobbing machine has been presented. In the design and development of the system, human computer interaction, programming algorithm and the design of each function module have bean done. Application test shows that the expected design requirements have been achieved.
