We have studied structural and superconducting properties of MgB 2 thin films doped with carbon during the hybrid physical-chemical vapor deposition process. A carbon-containing metalorganic precursor bis(methylcyclopentadienyl)magnesium was added to the carrier gas to achieve carbon doping. As the amount of carbon in the film increases, the resistivity increases, T c decreases, and the upper critical field increases dramatically as compared to clean films. The selffield J c in the carbon doped film is lower than that in the clean film, but J c remains relatively high to much higher magnetic fields, indicating stronger pinning. Structurally, the doped films are textured with columnar nano-grains and highly resistive amorphous areas at the grain boundaries. The carbon doping approach can be used to produce MgB 2 materials for high magnetic-field applications. a)Electronic address: avp11@psu.edu

The solubility of potassium clavulanate in ethanol, 1-propanol, 1-butanol, 2-propanol, and 2-methyl-1propanol between 273 K and 305 K were measured using a laser technique. This method was used to determine the dissolution of the solid phase in a solid + liquid mixture. Results of these measurements were correlated with a semiempirical equation.

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Polymorphic transformation of pravastatin sodium in a mixture of isopropanol and water was studied by use of online focused beam reflectance measurement (FBRM) and particle vision measurement (PVM). It is shown that the form A polymorph transformed to the stable polymorph, form B. It was speculated that in the transformation process there was an agglomeration and breakage phenomenon. The transformation mechanism was identified as solution-mediated phase transformation. Influences of temperature, solvent composition, and stirrer speed on the transformation process were examined. It can be seen from the FBRM monitoring results that higher temperature, larger ratio of water to isopropanol, and higher stirrer speed can increase the transformation process.

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Articles you may be interested inEffect of rare-earth doping on the superconducting properties of MgB 2

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Background Trunk-boring pests (TBPs) are an important type of forest pest, TBPs not only feed on the branches and trunks of trees, but also spread quarantine diseases in forests. However, because the larvae of TBPs live inside the trunk and are well concealed, prevention and control are difficult. The lack of effective control methods leads to the death of many trees in forests. In this study, a novel nanopesticide featuring high bioactivity and slow-release properties was developed to control TBPs. Thiacloprid (THI), which is commonly used to control Coleoptera species, was used as a model pesticide. Results The oleophobic properties of bovine serum albumin (BSA) were exploited to encapsulate the hydrophobic pesticide THI by self-assembly, and the size of the obtained nanoparticles, THI@BSA·NPs, was approximately 23 nm. The loading efficiency reached 70.4%, and THI@BSA·NPs could be released continuously for over 15 days, with the cumulative release reaching 93.5%. The fluorescein isothiocyanate (FITC)-labeled nanoparticles were evenly distributed in the digestive tract and body surface of a typical TBPs, M. alternatus, and the stomach and contact toxicities increased by 33.7% and 25.9%, respectively, compared with those of free THI. Furthermore, the results showed that the transport efficiency of THI@BSA·NPs was highest at a concentration of 50 μg/mL, and the THI@BSA·NPs content in the trunk, from to lower to higher layers, was 8.8, 8.2, 7.6, and 5.8 μg/g. At the same time, THI@BSA·NPs also exhibited high transport efficiency in dead trees. Conclusion The transport efficiency and toxicity of the active ingredients are the key factors for the control of TBPs. This work provided idea for the application of biological delivery system encapsulated hydrophobic pesticides. The novel self-assembled THI@BSA·NPs have promising potential for sustainable control of TBPs.