Quantitatively probing the magnetic behavior of individual nanoparticles by an AC field-modulated magnetic force microscopy

Despite decades of advances in magnetic imaging, obtaining direct, quantitative information with nanometer scale spatial resolution remains an outstanding challenge. Current approaches, for example, Hall micromagnetometer and nitrogen-vacancy magnetometer, are limited by highly complex experimental apparatus and a dedicated sample preparation process. Here we present a new AC field-modulated magnetic force microscopy (MFM) and report the local and quantitative measurements of the magnetic information of individual magnetic nanoparticles (MNPs), which is one of the most iconic objects of nanomagnetism. This technique provides simultaneously a direct visualization of the magnetization process of the individual MNPs, with spatial resolution and magnetic sensitivity of about 4.8 nm and 1.85 x 10(-20) A m(2), respectively, enabling us to separately estimate the distributions of the dipolar fields and the local switching fields of individual MNPs. Moreover, we demonstrate that quantitative magnetization moment of individual MNPs can be routinely obtained using MFM signals. Therefore, it underscores the power of the AC field-modulated MFM for biological and biomedical applications of MNPs and opens up the possibility for directly and quantitatively probing the weak magnetic stray fields from nanoscale magnetic systems with superior spatial resolution

GWAS Analysis and QTL Identification of Fiber Quality Traits and Yield Components in Upland Cotton Using Enriched High-Density SNP Markers

It is of great importance to identify quantitative trait loci (QTL) controlling fiber quality traits and yield components for future marker-assisted selection (MAS) and candidate gene function identifications. In this study, two kinds of traits in 231 F6:8 recombinant inbred lines (RILs), derived from an intraspecific cross between Xinluzao24, a cultivar with elite fiber quality, and Lumianyan28, a cultivar with wide adaptability and high yield potential, were measured in nine environments. This RIL population was genotyped by 122 SSR and 4729 SNP markers, which were also used to construct the genetic map. The map covered 2477.99 cM of hirsutum genome, with an average marker interval of 0.51 cM between adjacent markers. As a result, a total of 134 QTLs for fiber quality traits and 122 QTLs for yield components were detected, with 2.18–24.45 and 1.68–28.27% proportions of the phenotypic variance explained by each QTL, respectively. Among these QTLs, 57 were detected in at least two environments, named stable QTLs. A total of 209 and 139 quantitative trait nucleotides (QTNs) were associated with fiber quality traits and yield components by four multilocus genome-wide association studies methods, respectively. Among these QTNs, 74 were detected by at least two algorithms or in two environments. The candidate genes harbored by 57 stable QTLs were compared with the ones associated with QTN, and 35 common candidate genes were found. Among these common candidate genes, four were possibly “pleiotropic.” This study provided important information for MAS and candidate gene functional studies

Catalytic wet oxidation of aqueous methylamine: comparative study on the catalytic performance of platinum–ruthenium, platinum, and ruthenium catalysts supported on titania

<div><p>Promotion of the dispersion of Ru species supported on TiO₂ was achieved by introduction of Pt component and the role of Pt in enhancing the catalytic performances of Pt–Ru was investigated with catalytic wet air oxidation of methylamine used as a probing reaction. It was found that Pt–Ru/TiO₂ displayed a much better catalytic performance compared with Pt/TiO₂ and Ru/TiO₂ catalysts due to having the highest dispersion of active species. Both high total organic carbon conversion and nitrogen selectivity (∼100%) over Pt–Ru/TiO₂ catalyst were achieved at low temperature (200 °C). X-ray photoelectron spectroscopy characterization indicated that there were strong interactions between metal particles and the support, which may increase the catalytic performance of catalysts.</p></div

Electric Conductivity and Corrosion Resistance of Amorphous Carbon Films Prepared by Direct Current Magnetron Sputtering on304 Stainless Steel

The conductive amorphous carbon films were deposited on the 304SS by conventional direct current magnetron sputtering. The effect of substrate bias on the microstructure and property of amorphous carbon films were mainly investigated. The results show that the electrical conductivity and corrosion resistance are improved significantly for the carbon films coated stainless steel in comparison to the untreated ones. Specifically, when the substrate bias was -200 V the contact resistance was about 16.65 mOmega·cm~2, which may be ascribed to the highest fraction of sp~2 bonds under the normal compacting force of the fuel cells at 1.5 MPa. The corrosion potential of the carbon films coated stainless steel significantly increased in the simulated PEM fuel cells environment, while the corrosion current density obviously decreased, especially when the bias was - 200 V the carbon film performs the best corrosion resistance, which may be attributed to its best compactness, for this case the corrosion current density is 1.22*10~(-8) A/cm~2 and the corrosion potential is 0.25 V

A holistic strategy for quality and safety control of traditional Chinese medicines by the “iVarious” standard system

An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines (TCMs). However, the current quality standard research lacks the top-design and systematic design, mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named “iVarious”, was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the “iVarious” system. This system highlighted a holistic strategy for effectiveness, security, integrity and systematization of quality and safety control standards of TCMs. The establishment of “iVarious” integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards