Direct visualization of iron sheath shielding effect in MgB_2 superconducting wires

Local magneto-optical imaging and global magnetization measurement techniques were used in order to visualize shielding effects in the superconducting core of MgB_2 wires sheathed by ferromagnetic iron (Fe). The magnetic shielding can provide a Meissner-like state in the superconducting core in applied magnetic fields up to ~1T. The maximum shielding fields are shown to correlate with the saturation fields of magnetization in Fe-sheaths. The shielding has been found to facilitate the appearance of an overcritical state, which is capable of achieving a critical current density (J_c) in the core which is larger than J_c in the same wire without the sheath by a factor of ~2. Other effects caused by the magnetic interaction between the sheath and the superconducting core are discussed.Comment: 4 pages, 3 figure

Mapping and Analyzing Stakeholders in China’s Essential Drug System by Using a Circular Model: Who We Should Deal with Next?

AbstractObjectivesTo predict the prospects of the essential drug system by using the Stakeholder Impact Index (SII) and evaluate the current performance of each main stakeholder and suggested dangerous stakeholders and dormant stakeholders.MethodsA Delphi method was used, involving 36 experts with experience in implementation and evaluation of the essential drug policy, to construct the circular model as well as evaluate the performance of each stakeholder.ResultsThe central government was a dominant stakeholder of the whole essential drug system. The provincial governments were definitive stakeholders, whereas local governments and medical institutions were dependent stakeholders. Furthermore, media and drug stores were dormant stakeholders and pharmaceutical manufacturers and delivery enterprises were dangerous stakeholders. Patients, community residents, and medical insurance programs were discretionary stakeholders. The SII for the essential drug system was positive (SIIproj⁎ = 2.72).ConclusionsThe overall anticipation of the essential drug policy is optimistic. Letting definitive stakeholders (provincial governments) having more autonomy can efficiently accelerate the pace of implementation of the essential drug policy in the current situation. Central government, however, also needs to construct an experience exchange platform with the aim of building versatile methods for running the essential drug system in all provinces. Pharmaceutical manufacturers and delivery enterprises were dangerous stakeholders for the essential drug policy. Because of their potential threat to the implementation of the policy, the central government should motivate them to support the construction of the essential drug system spontaneously. In that case, provincial governments need to construct a fair, balanced, and self-stabilized bidding platform

A new millipede (Diplopoda, Helminthomorpha) from the Middle Triassic Luoping biota of Yunnan, Southwest China

AbstractA new helminthomorph millipede,Sinosoma luopingensenew genus new species, from the Triassic Luoping biota of China, has 39 body segments, metazonites with lateral swellings that bear a pair of posterolateral pits (?insertion pits for spine bases), and sternites that are unfused to the pleurotergites. This millipede shares a number of characters with nematophoran diplopods, but lacks the prominent dorsal suture characteristic of that order. Other “millipede” material from the biota is more problematic. Millipedes are a rare part of the Luoping biota, which is composed mainly of marine and near-shore organisms. Occurrences of fossil millipedes are exceedingly rare in Triassic rocks worldwide, comprising specimens from Europe, Asia, and Africa, and consisting of juliform millipedes and millipedes that are either nematophorans or forms very similar to nematophorans.</jats:p

Worshipers and Warriors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68415/2/10.1177_009770047600200102.pd

Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China

Abstract Horseshoe crabs are classic “living fossils”, supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived

Evaluation of a solid nitrogen impregnated MgB2 racetrack coil

To develop powerful wind turbine generators using superconducting technology, high-performance superconducting racetrack coils are essential. Herein, we report an evaluation of a multifilamentary magnesium diboride (MgB2) conductor-based racetrack coil cooled and impregnated simultaneously by solid nitrogen (SN2). The coil was wound on a copper former with 13 mm winding width, an inner diameter of 124 mm at the curvature, and 130 mm length of the straight section. An in situ processed S-glass-insulated 36-filament MgB2 wire was wound on the former in two layers with 19.5 turns, and heat treated via the wind and react method without any epoxy resin. The coil was evaluated for critical temperature and transport critical current in the SN2 environment at different temperatures up to 31.3 K in self-field. The coil was able to carry 200 A transport current at 28.8 K in self-field. During coil charging and operation, SN2 effectively acted as an impregnation material. The test results demonstrate the viability to use MgB2 racetrack coil potentially with SN2 impregnation in advanced rotating machine applications