Fabrication and transport critical currents of multifilamentary MgB2/Fe wires and tapes

Multifilamentary MgB2/Fe wires and tapes with high transport critical current densities have been fabricated using a straightforward powder-in-tube (PIT) process. After annealing, we measured transport jc values up to 1.1 * 105 A/cm2 at 4.2 K and in a field of 2 T in a MgB2/Fe square wire with 7 filaments fabricated by two-axial rolling, and up to 5 * 104 A/cm2 at 4.2 K in 1 T in a MgB2/Fe tape with 7 filaments. For higher currents these multifilamentary wires and tapes quenched due to insufficient thermal stability of filaments. Both the processing routes and deformation methods were found to be important factors for fabricating multifilamentary MgB2 wires and tapes with high transport jc values.Comment: 13 pages, 7 figure

Seed germination of three dominant Artemisia species in loess hilly region: alternating temperature, osmotic potential, and light effects

Non-Peer ReviewedIn this study, we evaluated the effects of alternating temperature, osmotic potential and light in the achene germination of three dominant Artemisia species (A. scoparia, A. gmelinii Web. and A. giraldii Pamp.) on arable old land after being abandoned in loess hilly region of Northern Shaanxi, in order to provide information about germination requirements which could be use for conservation studies. Results showed that A. scoparia had wider alternating temperature extremes than two other species and A. giraldii Pamp. and A. gmelinii Web. had lower optimum alternating temperature (25 oC/20 oC) than A. scoparia (30 oC/25 oC). Osmotic potential affected germination of all species significantly, but A. scoparia had better germination results than others in every treatment. In light treatments, although A. giraldii Pamp. and A. gmelinii Web. had lower germination proportion in white light, they had bigger germination proportion in darkness than A. scoparia

Anatomic Insights into Disrupted Small-World Networks in Pediatric Posttraumatic Stress Disorder.

Purpose To use diffusion-tensor (DT) imaging and graph theory approaches to explore the brain structural connectome in pediatric posttraumatic stress disorder (PTSD). Materials and Methods This study was approved by the relevant research ethics committee, and all participants’ parents or guardians provided informed consent. Twenty-four pediatric patients with PTSD and 23 control subjects exposed to trauma but without PTSD were recruited after the 2008 Sichuan earthquake. The structural connectome was constructed by using DT imaging tractography and thresholding the mean fractional anisotropy of 90 brain regions to yield 90 × 90 partial correlation matrixes. Graph theory analysis was used to examine the group-specific topologic properties, and nonparametric permutation tests were used for group comparisons of topologic metrics. Results Both groups exhibited small-world topology. However, patients with PTSD showed an increase in the characteristic path length (P = .0248) and decreases in local efficiency (P = .0498) and global efficiency (P = .0274). Furthermore, patients with PTSD showed reduced nodal centralities, mainly in the default mode, salience, central executive, and visual regions (P < .05, corrected for false-discovery rate). The Clinician-Administered PTSD Scale score was negatively correlated with the nodal efficiency of the left superior parietal gyrus (r = −0.446, P = .043). Conclusion The structural connectome showed a shift toward “regularization,” providing a structural basis for functional alterations of pediatric PTSD. These abnormalities suggest that PTSD can be understood by examining the dysfunction of large-scale spatially distributed neural networks