Abstract: The present invention provides use of a photoperiod-sensitive genic male sterility mutant of cotton in crossbreeding or hybrid seed production. The fertility of the photoperiod-sensitive genic male sterility mutant of cotton is influenced by the photoperiod. The photoperiod characteristic of the photoperiod-sensitive genic male sterility mutant of cotton is that, the photoperiod-sensitive genic male sterility mutant of cotton shows normal fertility when the illumination time is shorter than 11.5 h and shows genic male sterility when the illumination time is longer than 12 h; the photoperiod-sensitive genic male sterility mutant of cotton is in a fertility change period when the illumination time is in a range of 11.5-12 h and has less pollen. The photoperiod-sensitive genic male sterility mutant of cotton is PSM1, and/or a photoperiod-sensitive genic sterile line obtained through selective breeding of hybridized and/or backcrossed and/or self-bred offsprings of the PSM1.

Abstract: The present invention provides use of a photoperiod-sensitive genic male sterility mutant of cotton in crossbreeding or hybrid seed production. The fertility of the photoperiod-sensitive genic male sterility mutant of cotton is influenced by the photoperiod. The photoperiod characteristic of the photoperiod-sensitive genic male sterility mutant of cotton is that, the photoperiod-sensitive genic male sterility mutant of cotton shows normal fertility when the illumination time is shorter than 11.5 h and shows genic male sterility when the illumination time is longer than 12 h; the photoperiod-sensitive genic male sterility mutant of cotton is in a fertility change period when the illumination time is in a range of 11.5-12 h and has less pollen. The photoperiod-sensitive genic male sterility mutant of cotton is PSM1, and/or a photoperiod-sensitive genic sterile line obtained through selective breeding of hybridized and/or backcrossed and/or self-bred offsprings of the PSM1.

Abstract: A built-in spatial hammer type impact damper placed in steel tube structures is provided. A spherical mass oscillator is fixed in the center of an annular sheet housing through springs on the oscillator. Many rigid rods are fixed on the spherical mass oscillator. The annular housing, spherical mass oscillator and springs form a tuned mass damper to offset the vibration of a steel pipe structure caused by external excitation. In addition, viscoelastic energy absorbing caps are settled on the top of the rigid rods and will collide with the sheet housing when host structure vibrating. Multiple springs and rigid rods in an annular plane can reduce the level of vibration in multiple directions. Many dampers are connected through connecting rods to form a spatial hammer type damper which is placed in a circular steel pipe. Vibration reduction efficiency can be increased and the space occupied by dampers can be reduced.