A novel dual-stator hybrid excited synchronous wind generator

This paper presents a novel dual-stator hybrid excited synchronous wind generator and describes its structural features and operation principle. The no-load magnetic fields with different field currents are computed by 3-D finite-element method. Static characteristics, including the flux-linkage and EMF waveforms of stator windings, and inductance waveforms of armature windings and field winding, are analyzed. The simulation results show that due to the dual-stator structure, the air-gap magnetic flux can be easily controlled, while the output voltage can be increased effectively. Tests are performed on the prototype machine to validate the predicted results, and an excellent agreement is obtained

Development, in vitro biocompatibility, and antitumor efficacy of acetic acid-modified Cordyceps sinensis polysaccharide nanoparticle drug delivery system

Docetaxel-loaded acetic acid conjugated Cordyceps sinensis polysaccharide (DTX-AA-CSP) nanoparticles were prepared through dialysis and their release rates in vitro, particle sizes, zeta potentials, drug loading capacities, and encapsulation efficiencies were characterized for the synthesis of AA-modified CSPs from traditional Chinese medicine Cordyceps sinensis (Berk.) Sacc. Then, the AA-modified CSPs were characterized by 1 H-NMR and FT-IR. Furthermore, the biocompatibility of the delivery carrier (AA-CSP nanoparticles) was assessed on human umbilical vein endothelial cells. In vitro antitumor activity studies on DTX-AA-CSP nanoparticles were conducted on the human liver (HepG2) and colon cancer cells (SW480). The DTX-AA-CSP nanoparticles were spherical and had an average size of 98.91±0.29 nm and zeta potential within the −19.75±1.13 mV. The encapsulation efficiency and loading capacity were 80.95%±0.43% and 8.09%±0.04%, respectively. In vitro, DTX from the DTX-AA-CSP nanoparticles exhibited a sustained release, and the anticancer activities of DTX-AA-CSP nanoparticles against SW480 and HepG2 were significantly higher than those of marketed docetaxel injection (Taxotere®) in nearly all the tested concentrations. The AA-CSP nanoparticles showed good biocompatibility. This study provided a promising biocompatible delivery system for carrying antitumor drugs for cancer therapy

Mechanism for Selective Binding of Aromatic Compounds on Oxygen-Rich Graphene Nanosheets Based on Molecule Size/Polarity Matching

Selective binding of organic compounds is the cornerstone of many important industrial and pharmaceutical applications. Here, we achieved highly selective binding of aromatic compounds in aqueous solution and gas phase by oxygen-enriched graphene oxide (GO) nanosheets via a previously unknown mechanism based on size matching and polarity matching. Oxygen-containing functional groups (predominately epoxies and hydroxyls) on the nongraphitized aliphatic carbons of the basal plane of GO formed highly polar regions that encompass graphitic regions slightly larger than the benzene ring. This facilitated size match–based interactions between small apolar compounds and the isolated aromatic region of GO, resulting in high binding selectivity relative to larger apolar compounds. The interactions between the functional group(s) of polar aromatics and the epoxy/hydroxyl groups around the isolated aromatic region of GO enhanced binding selectivity relative to similar-sized apolar aromatics. These findings provide opportunities for precision separations and molecular recognition enabled by size/polarity match–based selectivity

In Situ Hydrothermal Grown Silicalite-1 Coating for Solid-Phase Microextraction

A novel fiber coated with silicalite-1 for solid-phase microextraction (SPME) was prepared by in situ hydrothermal growth method. Six substituted benzenes (nitrobenzene, <i>p</i>-dichlorobenzene, <i>m</i>-dichlorobenzene, 1,3,5-trichlorobenzene, <i>p</i>-chloronitrobenzene, and <i>m</i>-chloronitrobenzene) were employed as model analytes. The fiber exhibited high thermal stability (little weight loss up to 600 °C) and high chemical stability (no loss of function after sequential immersion in 0.1 M HCl, 0.01 M NaOH, methanol, and <i>n</i>-hexane each for at least 4 h). Compared with commercial fibers, 3–6 times higher extraction efficiencies were shown on the fiber for mono- and <i>p</i>-substituted benzenes. Under the preoptimized conditions, the fiber afforded satisfactory enhancement factors (517–1292), wide linear ranges (more than 2 orders of magnitude), low limits of detection (0.001–0.130 μg/L), and acceptable repeatability (<9.6%) and reproducibility (<8.8%). Furthermore, the fiber offered distinct shape-selectivity attributed to the uniform molecular-scale pore structure of silicalite-1. The ratios of extraction were approximately 70 between <i>p</i>-dichlorobenzene and 1,3,5-trichlorobenzene, 30 between <i>p</i>-chloronitrobenzene and <i>m</i>-chloronitrobenzene, and 3 between <i>p</i>-dichlorobenzene and <i>m</i>-dichlorobenzene. After pore narrowing by surface modification with SiCl₄, the selectivity for <i>p</i>-dichlorobenzene over <i>m</i>-dichlorobenzene was further enhanced by another 10 times. Finally, the fiber was successfully applied to analysis of a real water sample

Influence of magnet eddy current on magnetization characteristics of variable flux memory machine

In this paper, the magnet eddy current characteristics of a newly developed variable flux memory machine (VFMM) is investigated. Firstly, the machine structure, non-linear hysteresis characteristics and eddy current modeling of low coercive force magnet are described, respectively. Besides, the PM eddy current behaviors when applying the demagnetizing current pulses are unveiled and investigated. The mismatch of the required demagnetization currents between the cases with or without considering the magnet eddy current is identified. In addition, the influences of the magnet eddy current on the demagnetization effect of VFMM are analyzed. Finally, a prototype is manufactured and tested to verify the theoretical analyses

Dynamic analysis of planetary gear train system with double moduli and pressure angles

The planetary gear transmission with double moduli and pressure angles gearing is proposed for meeting the low weight high reliability requires. A dynamic differential equation of the NGW planetary gear train system with double and pressure angles is established. The 4-Order Runge-Kutta numerical integration method is used to solve the equations from which the result of the dynamic response is got. The dynamic load coefficients are formulated and are compared with those of the normal gear train．The double modulus planetary gear transmission is designed and manufactured. The experiment of operating and vibration are carried out and provides

Dynamic analysis of planetary gear train system with double moduli and pressure angles

The planetary gear transmission with double moduli and pressure angles gearing is proposed for meeting the low weight high reliability requires. A dynamic differential equation of the NGW planetary gear train system with double and pressure angles is established. The 4-Order Runge-Kutta numerical integration method is used to solve the equations from which the result of the dynamic response is got. The dynamic load coefficients are formulated and are compared with those of the normal gear train．The double modulus planetary gear transmission is designed and manufactured. The experiment of operating and vibration are carried out and provides