Observation of Atomic Dynamic Behaviors in the Evaporative Cooling by In-Situ Imaging the Plugged Hole of Ultracold Atoms

We experimentally observe the dynamic evolution of atoms in the evaporative cooling, by in-situ imaging the plugged hole of ultracold atoms. Ultracold rubidium atoms confined in a magnetic trap are plugged using a blue-detuned laser beam with a waist of 20 m at a wavelength of 767 nm. We probe the variation of the atomic temperature and width versus the radio frequency in the evaporative cooling. Both the behaviors are in good agreement with the calculation of the trapping potential dressed by the rf signal above the threshold temperature,while deviating from the calculation near the phase transition. To accurately obtain the atomic width, we use the plugged hole as the reference to optimize the optical imaging system by precisely minimizing the artificial structures due to the defocus effect.

Piglets Behavior Characteristics under Breeding Mode of Microbial Fermentation Bed

[Objective] This experiment aimed to compare piglets behavior under microbial fermentation bed breeding mode and traditional rearing mode. [Method] Pig behavior＇s statistical analysis under both microbial fermentation bed pig breeding mode and traditional rearing mode was se lected to study the effect of different breeding environment on pig＇s growth [ Result] The results showed that the duration of piglets lying and sleeping behavior accounted for the highest proportion of tested behavior, up to more than 70% ,followed by feeding and drinking which reached 15.96% （under microbial fermentation bed breeding mode） and 9.33% （under traditional rearing mode） respectively. Compared with traditional intensive rearing mode, piglet exploratory behavior＇s occurrence probability and duration increased significantly, by 28.62% and 12.21% respectively. Fighting behavior＇s occurrence probability and duration decreased significantly, by 49.83% and 91.26% respectively. Nutrient index and health index were introduced to evaluate piglet＇s general heath condition under microbial fermentation bed breeding mode, and results indicated that the health index of piglets under microbial fermentation bed breeding mode had slight difference from that under traditional mode, namely 10.83 and 10.03 respectively. But health index of piglets under microbial fermentation bed breeding mode was 245.12, much higher than 21.96 under traditional mode. [ Conclusion] Piglets would be healthier under microbial fermentation bed breeding mode.

Crossing experiments and behavioral observations reveal reproductive incompatibility among three putative species of the whitefly Bemisia tabaci

The whitefly Bemisia tabaci has a global distribution and extensive genetic diversity. Recent phylogenetic analyses as well as crossing experiments suggest that B. tabaci is a complex composed of 〉 20 cryptic species, but more crossing studies are required to examine the reproductive compatibility among the putative species and thus further clarify the systematics of this species complex. We conducted crossing experiments and behavioral observations to investigate the reproductive compatibility between the Mediterranean, Asia II 3, and Asia II 1 putative species ofB. tabaci collected from Zhejiang, China. Female progeny were never produced in inter-species crosses, demonstrating a lack of egg fertilization; while 55%-75% females were produced in all the intra-species treatments. Continuous behavioral observations showed that frequent courtship events occurred in both intra-species treatments and inter-putative species crosses. However, copulation events occurred only in the three intra-species treatments with one exception： that one copulation event occurred between Asia II 3 and Mediterranean in the crosses where two cohorts of females and males of different putative species were enclosed together in a small arena but were not allowed access to their intra-specific mates for a long period of time. These data demonstrated complete reproductive isolation between the Mediterranean, Asia II 3, and Asia II 1 putative species, and further showed that the isolation is due to lack of copulation. Demonstration of reproductive isolation between the Mediterranean and two indigenous putative species from China provides further evidence for the existence of cryptic species within the B. tabaci complex.

In-situ TEM Observation of Cementite Coarsening Behavior of 5Mn Steel during Tempering

The cementite formation and coarsening behaviors of 0. 2 mass% C-5 mass% Mn steel during tempering at 500℃ were investigated by in-situ transmission electron microscope（ TEM）. In-situ TEM observation showed uniform distribution of cementite particles at the early stage of tempering in the rapidly heated（ 500 ℃ / s） sample. Elemental analysis confirmed that the cementite growth was dominated by Mn diffusion. During the cementite growth,the coarsening behavior of intragranular cementite was significantly controlled by the matrix diffusion,while that of the intergranular cementite was mainly governed by the boundary diffusion. The in-situ TEM observation revealed that the dislocation pipe diffusion of Mn took place during tempering,which accelerated the Mn diffusion between cementite particles. The coarsening rates of individual cementite particles were calculated based on the in-situ TEM observation.