ABSTRACT
Objective To study dynamic compression performance of adipose tissues, so as to further reveal the damage mechanism, and provide references for medical treatment.Methods Based on the improved split Hopkinson pressure bar (SHPB) experimental device, the adipose tissue dynamic compression experiment was conducted. The stress-strain curves of adipose tissues at different strain rates were obtained. Then the numerical model of SHPB was established, and the experimental process was simulated and analyzed. The numerical simulation for penetration process of 32 mm diameter rubber non-lethal projectile into the simulated target in human abdomen was carried out.Results Adipose tissues had a noticeable strain rate effect. The stress-strain curves at two high strain rates were approximately straight lines. The slope was similar, and the elastic modulus was 3.25 MPa, which was about 6 times of that under a quasi-static state. The simulation curves of fat SHPB were consistent with the experimental curves, which verified correctness of the constitutive model. In the process of non-lethal projectile penetrating human abdomen, an annular convex area similar to water wave appeared on skin surface, and the fat layer absorbed about 67% of the impact kinetic energy.Conclusions The experimental data of adipose tissues are very accurate. Numerical simulation can reproduce the penetration process well, and provide references for studying the damaging effect of non-lethal weapons on human body.
ABSTRACT
Field studies were conducted for a season to determine potential for alterations in the rhizosphere fungi quantity dynamics and dominant populations of 4 wild sugarcane clones(S.spontaneum L.) with different UV-B sensitivity under an enhanced ultraviolet-B(UV-B,280 nm～310 nm) radiation.The quantity of rhizosphere fungi was most in tillering stage,second in seedling stage and lest in elongating stage and maturing stage,the sequence wasn’t alternated by UV-B radiation.The rhizosphere fungi quantity of tolerant clone was obviously increased and greater than the sensitive clone under the enhanced UV-B radiation,however,the number of dominant populations decreased and Penicillium was the dominant population during the periods of 4 wild sugarcane clones.
ABSTRACT
The importance and feasibility was analyzed of the teaching BBS for aiding classroom teaching based on campus network. The design, technique, content, advantages and deficiencies were presented of agricultural microbiology teaching BBS. The prospect also was discussed of teaching BBS based on campus network in this paper.