A Flyback Converter-based Hybrid Balancing Method for Series-Connected Battery Pack in Electric Vehicles

An active balancing method based on two flyback converters is proposed for series-connected battery pack. Balanced energy can be transferred between the whole battery and any single cell. The proposed topology reduces the number of energy storage components, the volume and the cost of the balancing system. And it has the characteristics of fast balancing speed and high balancing efficiency. Based on the topology, a dual-objective hybrid control strategy is proposed, which can reduce the highest voltage and boost the lowest voltage in the charging or discharging process of the cells simultaneously, so as to improve the balancing speed. Simulation and experimental results show that the proposed method has a good balancing effect and can significantly improve the consistency of series battery pack. This work is potentially significant in terms of improved reliability of battery packs and savings of costs and lives in safety-critical applications

Construction and Characterization of a Chimeric Virus (BIV/HIV-1) Carrying the Bovine Immunodeficiency Virus \u3ci\u3egag\u3c/i\u3e-\u3ci\u3epol\u3c/i\u3e Gene: Research Letters

HIV-1HXB2 5′LTR region, most of BIVR29 gag-pol segment and HIV-1HXB2 pol IN-3′LTR region were respectively amplified. A chimeric clone, designated as pHBIV3753, was constructed by cloning three fragments sequentially into pUC18. MT4 cells were transfected with pHBIV3753. The replication and expressions of the chimeric virus (HBIV3753) were monitored by RT activity and IFA. The results firstly demonstrated that it is possible to generate a new type of the BIV/HIV-1 chimeric virus containing BIV gag-pol gene

A Survey of Chinese Pig Farms and Human Healthcare Isolates Reveals Separate Human and Animal Methicillin-Resistant Staphylococcus aureus Populations.

There has been increasing concern that the overuse of antibiotics in livestock farming is contributing to the burden of antimicrobial resistance in people. Farmed animals in Europe and North America, particularly pigs, provide a reservoir for livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA ST398 lineage) found in people. This study is designed to investigate the contribution of MRSA from Chinese pig farms to human infection. A collection of 483 MRSA are isolated from 55 farms and 4 hospitals in central China, a high pig farming density area. CC9 MRSA accounts for 97.2% of all farm isolates, but is not present in hospital isolates. ST398 isolates are found on farms and hospitals, but none of them formed part of the "LA-MRSA ST398 lineage" present in Europe and North America. The hospital ST398 MRSA isolate form a clade that is clearly separate from the farm ST398 isolates. Despite the presence of high levels of MRSA found on Chinese pig farms, the authors find no evidence of them spilling over to the human population. Nevertheless, the ST398 MRSA obtained from hospitals appear to be part of a widely distributed lineage in China. The new animal-adapted ST398 lineage that has emerged in China is of concern

Directed computer aided design using expert systems techniques

The work reported here is an examination into the interfacing of software. The general objective of the study was to investigate the methods of communication between software packages in a local environment. The software packages discussed have been grouped into four areas: language; database/spreadsheet/word processor; CAD and CAM. The study specifically follows a design process to illustrate methods of collecting and transferring data between user and CAD/CAM software packages which deal with specific aspects in the design process, such as drawing, analysis and manufacturing. The design of a shaft and its associated components was deliberately chosen for investigation because shaft design is one of the most common steps in machine design. The shaft design assistant system was developed based on the MicroStation environment and most parts are written in MicroStation Development Language which is another area of interest explored in this study. Incorporated into the shaft design is the framework of a knowledge-based module which assists the designer in the selection of suitable bearings. This design process was developed in Prolog to provide an example of communication between MDL applications and programs written in other languages. This module also shows the basic concept of how knowledge based systems are applied to engineering component selection. The interface issues were addressed along with the development of the shaft design assistant system

Effects of an Intratympanic Injection of Dexamethasone Combined with Gentamicin on the Expression Level of Serum P0 Protein Antibodies in Patients with Meniere’s Disease

OBJECTIVES: To investigate the effects of an intratympanic injection of dexamethasone combined with gentamicin on the expression level of serum P0 protein antibodies in patients with Meniere’s disease (MD). METHODS: A total of 136 patients with MD treated in our hospital were enrolled in this study. Among them, 68 patients were treated with an intratympanic injection of dexamethasone combined with gentamicin (observation group). Another 68 patients were treated with gentamicin alone (control group). RESULTS: After treatment, the expression levels of IgG and IgM in the two groups significantly decreased (po0.05); the levels in the observation group were significantly lower than those in the control group (po0.05). The incidences of vertigo, tinnitus, and gait instability in the observation group were significantly lower than those in the control group (po0.05). Vestibular symptom index (VSI) scores in the observation group were significantly lower than those in the control group (po0.05). We observed no significant difference between the two groups in the number of vertigo attacks 6 months after treatment (p40.05). CONCLUSION: For patients with MD, dexamethasone combined with gentamicin can reduce the incidence of vertigo, tinnitus, and gait instability, but it has no effect on the efficacy or number of vertigo attacks 6 months after treatment. Therefore, the levels of myelin P0 protein antibodies after treatment can be used as predictors of vertigo at 6 months after treatment

Chemical vapor deposition for few‐layer two‐dimensional materials

Abstract Chemical vapor deposition (CVD) approach offers a controllable strategy for preparing large‐area and high‐quality few‐layer (mainly bilayer or trilayer) twisted or untwisted two‐dimensional (2D) materials, and is predicted to boost the development of 2D materials from laboratory research to industrial applications

Large electrical strain in lead-free K0.5Na0.5NbO3-based ceramics by heterovalent doping

Heterovalent doped (K0.48-0.07xNa0.52-0.43xBi0.5x)(Nb0.95-0.95xSb0.05-0.05xZrx)O3 ceramics were fabricated using conventional solid-state reaction. Then, the phase structures, dielectric, ferroelectric, and electric-strain properties were investigated. The compositions were tuned to be located at polymorphic phase boundary with increasing heterovalent Bi3+ and Zr4+ doping levels. A large strain of 0.19% was obtained at relatively low electric fields of 30 kV/cm in the composition of x = 0.04. The normalized large-signal d33∗ values were approximately 633 pm/V under a low driving electric field of 30 kV/cm, which were comparable or larger than the values reported for other lead-free families. The large strains obtained can be attributed to the formation of nanodomains and high-density domain walls, which were confirmed by the observations of domain morphology using transmission electron microscopy (TEM) technique. Excellent temperature stability of the strain properties of the x = 0.04 sample could be ascribed to the sluggish behaviour for the local structural heterogeneity in heterovalent-ion doped KNN ceramic. Theoretical simulations revealed that the Zr4+ produce the local stress at the BO6 octahedra and Bi3+ could yield off-centering of AO12 ployhedron due to the nature of Bi 6s lone pair electrons, which induced lattice expansion and local distortions in the sample. The local displacements are strongly anisotropic in heterovalent-ion doped system. It is believed that random local fields exist in these compositions owing to the eixstence of charge distribution. Such heterovalent doping of Bi3+ and Zr4+ could destory simultaneously the orthorhombic symmetry and the short-range ferroelecctric order, leading to the formation of complex nanodomains and local structral hetergenenity. Heterovalent doping may, therefore, offer a new avenve to design novel K0.5Na0.5NbO3 (KNN) -based materials for their mutifunctional applications

Mass-Mediated Phase Modulation of Thin Molybdenum Nitride Crystals on a Liquid Cu-Mo Alloy

The high-quality and controllable preparation of molybdenum nitrides (MoxNy) will significantly advance the fields of heterogeneous catalysis, energy storage, and superconductivity. However, the complex structure of MoxNy, which contains multiple phases, makes exploring the structure-property relationship challenging. The selective preparation of MoxNy with distinct phases is undoubtedly an effective method for addressing this issue, but it is lacking experimental cases and theoretical reports. Here we demonstrate a feasible chemical vapor deposition (CVD) strategy for selectively producing γ-Mo2N or δ-MoN through modulating the mass quantity of N precursors. A liquid Cu-Mo alloy was used as a Mo precursor and catalyst in this system. The resulting γ-Mo2N was systematically characterized and found to be of high quality. Furthermore, the morphology evolutions of γ-Mo2N and δ-MoN with growth time were summarized in detail, as a result of growth and etching dynamics. This work promotes the phase modulation of MoxNy and provides a framework for future research on the structure-property relationship