矿山设备润滑磨损状态智能分析技术

综合应用统计分析、预测理论、模式识别、神经网络和专家系统等多项技术，针对德兴铜矿设备状态监测的实际情况。研究设备润滑磨损状态智能分析技术。     

Hexon-only binding of VP26 reflects differences between the hexon and penton conformations of VP5, the major capsid protein of herpes simplex virus

VP26 is a 12-kDa capsid protein of herpes simplex virus 1. Although VP26 is dispensable for assembly, the native capsid (a T=16 icosahedron) contains 900 copies: six on each of the 150 hexons of VP5 (149 kDa) but none on the 12 VP5 pentons at its vertices. We have investigated this interaction by expressing VP26 in Escherichia coli and studying the properties of the purified protein in solution and its binding to capsids. Circular dichroism spectroscopy reveals that the conformation of purified VP26 consists mainly of beta-sheets (approximately 80%), with a small alpha-helical component (approximately 15%). Its state of association was determined by analytical ultracentrifugation to be a reversible monomer-dimer equilibrium, with a dissociation constant of approximately 2 x 10(-5) M. Bacterially expressed VP26 binds to capsids in the normal amount, as determined by quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cryoelectron microscopy shows that the protein occupies its usual sites on hexons but does not bind to pentons, even when available in 100-fold molar excess. Quasi-equivalence requires that penton VP5 must differ in conformation from hexon VP5: our data show that in mature capsids, this difference is sufficiently pronounced to abrogate its ability to bind VP26.     

The adenomatoid odontogenic tumor: an analysis of 57 cases in a black African population

PURPOSE: This study analyzed the findings in a large series of adenomatoid odontogenic tumors (AOT) in Nigerians. PATIENTS AND METHODS: Hospital records of all cases of AOT diagnosed at three teaching hospitals were reviewed and analyzed. RESULTS: Most of the tumors were intraosseous (central) (98.3%) and of the follicular type (75%). Females were more frequently affected than males (1.4:1), and patients in their second decade of life were most frequently affected (75%). Patients with follicular AOT were relatively younger (15.2 +/- 5.6 years) than those with extrafollicular tumors (20.9 +/- 13.8 years). However, males who presented with extrafollicular tumors (14.6 +/- 3.9 years) were relatively younger than their female counterparts (24.9 +/- 16 years). The maxilla was affected nearly twice as often as the mandible (1.8:1), and the canine tooth was frequently embedded in the tumor (76.9%). Although follicular tumors were most frequently located in the maxilla (76.3%), extrafollicular tumors were more commonly found in the mandible (69.2%). CONCLUSION: The distribution of this tumor in black Africans does not appear to be substantially different from that reported in caucasians.     

Titanium-assisted growth of silica nanowires: from surface-matched to free-standing morphologies

We report on an oxide-assisted growth technique for silica nanowires which allows tuning the growth from surface-matched nanowires to free-standing morphologies based on growth control by Ti in the role of a catalyst and surfactant. Using an adjustable Ti concentration, we grew silica nanowires with lengths ranging from 100 nm up to several millimetres whose defect chemistry was analysed by electron microscopy tools, monochromatic cathodoluminescence imaging and time resolved photoluminescence spectroscopy. The knowledge of the luminescence properties and the related defect occurrence along with their spatial distribution is pivotal for advancing silica nanowire growth in order to realize successful device designs based on self-assembled Si/SiO(x) nanostructures. We demonstrate a core-shell structure of the grown nanowires with a highly luminescent 150 nm thick shell and outstandingly fast decaying dynamics (≈1 ns) for glass-like materials. The conjunction of the observed efficient and stable luminescences with their attributed decaying behaviours suggests applications for silica nanowires such as active and passive optical interconnectors and white light phosphors. The identification of a time domain difference for the spectral regime from 2.3 to 3.3 eV, within the confined spatial dimensions of a single nanowire, is very promising for future, e.g. data transmission applications, employing silica nanowires which exhibit achievable compatibility with commonly applied silicon-based electronics. A qualitative growth model based on silica particle diffusion and Ti-assisted seed formation is developed for the various types of segregated silica nanowires which extends commonly assumed oxide-assisted growth mechanisms.     

经过优化的用于可再生能源系统的大功率逆变器

可再生能源市场正从全球金融危机中强劲反弹。先前延误或停工的项目已重新启动,许多新项目正在实施。这一高潮有力地掀起了整个供应链对可再生能源系统组件的需求,包括风力发电和光伏逆变器。全球风能理事会（GWEC）预测未来4年总装机容量的年均增长率为20.9%。这将使得到2014年风电总装机容量增加一倍以上,超过400GW。     

软特性650V IGBT：低电磁干扰和电压尖峰的优化器件

近年来,功率半导体厂商致力于提高器件的开关速度,这带来了开关损耗降低和系统能效提升的益处。这些功率器件需要优化的直流电路寄生电感（Ls）。为了满足具有大电流的高功率应用的需求,推出了一种全新的芯片650V IGBT4,旨在提供更大的设计自由度。这款全新的IGBT4器件具备更好的关断软度,并且由于关断电流变化率di／dr...     

改进的开关性能：快速IGBT带来新的挑战

降低动态功耗需要快速地开关功率半导体,但是,快速开关IGBT带来的新挑战,就是对关断电压峰值有特别强烈的影响。关断过程中uce-和ic测量分析说明了直流母线寄生电感和模块电感之间的相互作用。这使得在给定的应用中非常容易分析出的薄弱环节并在模拟中发现最大的潜力。     

On the Relation between Morphology and FET Mobility of Poly(3‐alkylthiophene)s at the Polymer/SiO2 and Polymer/Air Interface

The influence of the interface of the dielectric SiO₂ on the performance of bottom‐contact, bottom‐gate poly(3‐alkylthiophene) (P3AT) field‐effect transistors (FETs) is investigated. In particular, the operation of transistors where the active polythiophene layer is directly spin‐coated from chlorobenzene (CB) onto the bare SiO₂ dielectric is compared to those where the active layer is first spin‐coated then laminated via a wet transfer process such that the film/air interface of this film contacts the SiO₂ surface. While an apparent alkyl side‐chain length dependent mobility is observed for films directly spin‐coated onto the SiO₂ dielectric (with mobilities of ≈10^?3 cm² V^?1 s^?1 or less) for laminated films mobilities of 0.14 ± 0.03 cm² V^?1 s^?1 independent of alkyl chain length are recorded. Surface‐sensitive near edge X‐ray absorption fine structure (NEXAFS) spectroscopy measurements indicate a strong out‐of‐plane orientation of the polymer backbone at the original air/film interface while much lower average tilt angles of the polymer backbone are observed at the SiO₂/film interface. A comparison with NEXAFS on crystalline P3AT nanofibers, as well as molecular mechanics and electronic structure calculations on ideal P3AT crystals suggest a close to crystalline polymer organization at the P3AT/air interface of films from CB. These results emphasize the negative influence of wrongly oriented polymer on charge carrier mobility and highlight the potential of the polymer/air interface in achieving excellent “out‐of‐plane” orientation and high FET mobilities.