Practical research on coal pillar retention in deep mining roadways.

To address the limitations of traditional coal pillar design methods in engineering practice for deep retreat mining roadways, this research focuses on the retreat mining face at the Pinggang Coal Mine in Heilongjiang Province. Combining mechanical experiments, theoretical calculations, numerical simulations, and field tests, this study calculates the ultimate equilibrium size of coal pillars. It also analyses the stress transfer and surrounding rock plastic evolution characteristics under different coal pillar sizes in deep retreat mining faces and carries out a field engineering application.

[Forward genetic screening for zebrafish mutants defective in myelopoiesis].

Objective: To identify zebrafish mutants with myelopoiesis defects by ENU mutagenesis and large-scale forward genetic screening.

Methods: Male zebrafish were mutagenized with N-ethyl N-nitrosourea to induce mutations in the spermatogonial cells to generate the founders, which were outcrossed with AB to raise F1 fish. The F1 fish from different founders were mated to generate the F2 families.