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1.
Heliyon ; 10(6): e28303, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38560694

RESUMEN

The construction of gas extraction boreholes in soft coal seams is prone to collapse and deformation, and grouting reinforcement is one of the main methods to solve the problem of efficient sealing. However, the reasonable selection of key grouting parameters still needs further research. In response to the problem of selecting grouting sealing parameters for gas drainage drilling in soft coal seams, based on the "concentric ring" reinforcement sealing technology obtained in previous research, the key parameters and sealing technology of the "concentric ring" reinforcement were studied through theoretical calculation and numerical simulation experiments. The slurry diffusion morphology and range under different grouting pressures and grouting time slurry viscosity were obtained. Finally, in order to explore the application effect of key grouting parameters, on-site industrial tests were conducted in a soft and high gas coal seam. The research results indicate that the optimal grouting pressure for the "retaining wall rock hole ring" should not be less than 3 MPa, the reasonable grouting time should be 10-15 min, and the water material ratio of the grouting material should be greater than 1:1; The use of new reinforcement sealing and grouting technology can ensure long-term good extraction effect. Compared to the testing of drilling sealing effect using ordinary cloth bags with two plugs and one injection, The adoption of new reinforcement sealing technology can effectively prevent the deformation and collapse of the borehole before sealing, and due to two rounds of grouting and pre reinforcement of fractured coal, the sealing effect of the borehole is also relatively good. The research results have important theoretical value for guiding the drilling and sealing grouting engineering of gas extraction in soft coal seams.

2.
Appl Opt ; 60(5): 1357-1365, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33690579

RESUMEN

The Jones pupil is a full description of imaging properties of projection lenses in optical lithography. The decomposition of the Jones pupil into components with clear physical meanings was studied previously; however, the decomposition method has not been studied systematically. To generalize the existing decomposition method, this work is aimed at finding all the decomposition methods and analyzing the lithographic imaging impacts. In this work, six decomposition methods are proposed, and the lithographic imaging impacts of the Jones components are studied and compared for all the decomposition methods. The results demonstrate that, although the decomposition methods are different, their lithographic impacts are identical. To be specific, apodization has a dominant impact on the critical dimension with a magnitude of 1.3 nm, and the impact of diattenuation is 0.3 nm. In contrast, the impacts of the other Jones components of aberration, birefringence, rotator, and ellipticity are negligible. This work gives a complete understanding of the imaging impacts of the Jones pupil.

3.
Opt Express ; 21(19): 22145-52, 2013 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-24104106

RESUMEN

Clocking of lens elements is frequently used as an effective method of compensating for two-dimensional tolerances such as material inhomogeneity and surface figure errors. Typically, the lens designer has to determine the optimum angles of rotation by manually modeling lens element clocking in the commercial optical design software because the nature of errors resolved by lens clocking does not lead to good convergences for clocking optimization. In this paper, a method of automatic clocking optimization is developed. The method is implemented using a combination of particle swarm optimization algorithm and commercial optical design software. The optimum angles of rotation and predicted imaging performance are automatically calculated using this method. Methods of implementation and optimization examples are also given.

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