Salinity is a major abiotic stress at critical stages of seed germination and seedling establishment. Germination rate (GR) and field emergence rate (FER) are the key traits that determine the basic number of plants stand under field conditions. To explore molecular mechanisms in upland cotton under salt stress, a population of 177 recombinant inbred lines, and their parents were evaluated for seed germination traits (GP, germination potential; GR; FW, fresh weight; DW, dry weight; GL, germinal length) and seedling traits (FER; SH, seedling height; NL, number of main stem leaves) in 2016-2018.
View Article and Find Full Text PDFA low-cost deformable mirror (DM) group for wavefront correction in a small-aperture-beam fiber laser is reported in this paper. The DM group consists of nine single-actuator DMs and could act as a "virtual" 9-actuator DM arranged in a 3×3 array. The equivalent distance between two adjacent actuators could reach as small as 3 mm, which can lead to a relatively high lateral resolution.
View Article and Find Full Text PDFA deformable mirror with actuators of thermoelectric coolers (TECs) is introduced in this paper. Due to the bidirectional thermal actuation property of the TEC, both upward and downward surface control is available for the DM. The response functions of the actuators are investigated.
View Article and Find Full Text PDFBased on a mathematic model, the relation between the accuracy of the influence matrix and the performance of the wavefront correction is established. Based on the least squares method, a two-step system identification is proposed to improve the accuracy of the influence matrix, where the measurement noise can be suppressed and the nonlinearity of the deformable mirror can be compensated. The validity of the two-step system identification method is tested in the experiment, where improvements in wavefront correction precision as well as closed-loop control efficiency were observed.
View Article and Find Full Text PDFThe wavefront correction ability of a deformable mirror with a multireflection waveguide was investigated and compared via simulations. By dividing a conventional actuator array into a multireflection waveguide that consisted of single-actuator units, an arbitrary actuator pattern could be achieved. A stochastic parallel perturbation algorithm was proposed to find the optimal actuator pattern for a particular aberration.
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September 2013
Making use of the stretching effect of grazing incident laser beam, a novel method of wavefront correction was promoted. Without adding any extra beam expanding components, aberrations of wavefront could achieve satisfying correction by two grazing reflections along orthogonal directions on the deformable mirrors. The stretching effect expanded the beam size along grazing direction and the orientation dependent varying aberrations were well compensated as more actuators took effect in the correction process.
View Article and Find Full Text PDFBy introducing the rate equations and light intensity propagating equations into the fast Fourier transform-based calculation, the optical gain served as the connection between the light field and light intensity, its influence over mode pattern was studied. Thermal lens effect was also investigated by means of finite element analysis. The analysis was applied to a slab laser with a hybrid cavity.
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