Coal Structure Characteristics of the 2# Coal Seam in the Jiaozuo Mining Area and Its Geological Dependence.

To clarify the coal structure, spatial distribution, and controlling factors of the 2# coal seam in Jiaozuo mining, the drilling coal samples were collected to observe the coal type and coal structure. The coal macerals were identified by a MPVSP microscope photometer, and the spatial characteristics of the coal structure were obtained through interpreting deep lateral resistivity logging, natural gamma ray logging, density logging, and acoustic logging curves. The influence of coal properties, burial depth, geological stress, and faults on the coal structure were discussed correspondingly. The results exhibit that granulitic-mylonite coal was most developed in the 2# coal seam, followed by primary coal and cataclastic coal; the coal type was dominated by semibright coal, followed by clarain and semidull coal. Granulitic-mylonite, cataclastic, and primary coals were the main components of clarain, semibright coal, and semidull coal, respectively. Higher vitrinite and organic matter contents were conducive to the development of granulitic-mylonite. The coal structure combinations were spatially varied, and the granulitic-mylonite combinations were the most common. Granulitic-mylonite coal was developed in the east and south parts of the study area, and the coal structure was fragmented with a greater burial depth and larger thickness. The geological stress is the fundamental cause of coal structure damage as well as the cutting of faults.

Experimental investigation on True Triaxial Deformation and Progressive Damage Behaviour of Sandstone.

Studying the true triaxial deformation characteristics and progressive damage behavior of sandstone is of great significance for the stability control of roadways. Both the conventional triaxial test (CTT) and the true triaxial compression test (TTT) were conducted for sandstone to investigate its deformation characteristics and the variation laws of volume strain during the progressive damage process under different confining pressures. The conducted experiments showed that both the axial and lateral strains of the rock prior to failure under CTT conditions increased with increasing confining pressure. However, with increasing intermediate principal stress (σ2) under TTT conditions, both the axial strain, and the lateral strain (ε2) gradually decreased, and the lateral strain (ε3, expansion) first slow down and then accelerated. Moreover, the anisotropic characteristics first gradually weakened and then enhanced. The variation of the volume strain increment and the volume strain rate of rock combined with the acoustic emission activity and a three-dimensional rock theoretical model with microcrack defects were analyzed in detail. During the stable crack growth stage III, the volume strain increment and volume strain rate increased with increasing confining pressure under CTT conditions, while they decrease after the initial increase with increasing σ2 under TTT conditions. During the unstable crack growth stage IV, the volume strain increment increased sharply, while the volume strain rate gradually slowed down with increasing confining pressure under CTT conditions. The internal cracks of the rock were gradually suppressed and the lateral expansion was gradually constrained. The volume strain increment first increased followed by a decrease, and the volume strain rate gradually slowed down after a noticeable acceleration with increasing σ2 under TTT conditions. The internal micro-cracks gradually evolved from inhibition (in the planes parallel to plane 1-2 and plane 2-3) to accelerated expansion (the planes along the σ2 direction), and the lateral deformation first weakened and then strengthened.

Ion source and low energy injection line for a central region model cyclotron.

At CIAE, a 100 MeV H(-) cyclotron (CYCIAE-100) is under design and construction. A central region model (CRM) cyclotron was built for various experimental verifications for the CYCIAE-100 project and for research and development of high current injection to accelerate milliampere H(-) beam. The H(-) multicusp source built in 2003 has been improved recently to make the source operation more stable. A new injection line for axial low energy high current injection has been designed and constructed for the CRM cyclotron.

Matching from H(-) multicusp source to central region of a 100 MeV compact cyclotron for high current injection.

The way of matching the beam from an external ion source to the central region of the cyclotron CYCIAE-100 is presented in this article. The transverse acceptances of the central region were calculated, which provided the matching ellipse parameter requirements to the injection transport optics design. The optics of the injection line was simulated using TRANSOPTR, which allowed space charge effect calculation, and neutralization was taken into account.