基于最小速率保证的IEEE 80216e公平调度算法

针对IEEE 80216e协议的特点,提出了一种基于最小速率保证的IEEE 80216e 公平 调度（MTRFS）算法。算法支持多种业务流类型并可保障业务流的最小预约速率。该算法中 引入了补偿模式,以保障处在恶劣信道条件下的业务流的最小速率。同时,该算法对高级别 业务流和信道条件好的业务流提供尽可能多的带宽,以保障其QoS性能和系统吞吐量的最大 化。仿真表明,该算法能够保证业务流的最小预约速率,区别对待不同优先级的业务流;无 论是其公平性能还是吞吐量性能都优于传统的PF算法。该算法与IE     

水电站计算机监控系统单神经元自适应PID功率调节的研究

水力发电机组是一个复杂的非线性控制对象,为保证水电站发电机组功率调节具有快速、稳定的控制特性及良好的鲁棒性,本文提出在水电站计算机监控系统有功功率调节中采用单神经元自适应PID功率调节方式.PID控制的关键问题是PID参数的整定,单神经元自适应PID控制器由于其权值可以在线调整,具有较强的自学习和自适应能力,仿真结果表明改进的单神经元PID控制器比传统的控制器拥有更好的稳定性、动态性能和鲁棒性.     

Rational doping for zinc oxide and its influences on morphology and optical properties

Zinc oxide(ZnO) nanopowders doped with different metal ions(Me, Me = Sn4+, In3+, Mn2+, and Co2+) are prepared by a simple sol–gel method. Influences of the ion doping on morphology and optical properties of the resulting ZnxMeyO are investigated by scanning electron microscopy, X-ray diffraction, UV-vis absorption spectrum, and photoluminescence. The morphology of ZnO can be tailored by ion doping, which is closely related not only to the ionic radii and electronegativities of the doped ions, but also to their oxidation states and electron configurations. The optical band gap and photoluminescence of ZnO can also be modulated by ion doping, which results from a combination of different effects, Burstein–Moss, band tail, charge compensation, sp–d exchange, non-radiative recombination, and blocking barrier. This may offer us a viable approach to tuning the(optical) properties of ZnO-based materials via rational ion doping.     

Facile Assembly of 3D Binary Colloidal Crystals from Soft Microgel Spheres

It still remains a big challenge to fabricate binary colloidal crystals (binary CCs) from hard colloidal spheres, although a lot of efforts have been made. Here, for the first time, binary CCs are assembled from soft hydrogel spheres, PNIPAM microgels, instead of hard spheres. Different from hard spheres, microgel binary CCs can be facilely fabricated by simply heating binary microgel dispersions to 37 °C and then allowing them to cool back to room temperature. The formation of highly ordered structure is indicated by the appearance of an iridescent color and a sharp Bragg diffraction peak. Compared with hard sphere binary CCs, the assembly of PNIPAM microgel binary CCs is much simpler, faster and with a higher “atom” economy. The easy formation of PNIPAM microgel binary CC is attributed to the thermosensitivity and soft nature of the PNIPAM microgel spheres. In addition, PNIPAM microgel binary CCs can respond to temperature change, and their stop band can be tuned by changing the concentration of the dispersion.

     

Multi‐Responsive Polypeptidosome: Characterization,Morphology Transformation,and Triggered Drug Delivery

The biodegradable polymeric nanomedicines that may be integrated with multi‐stimuli‐sensitivity to achieve triggered or on‐demand drug release kinetics are challenging for polymer therapeutics and drug delivery systems. By controlling the structure transformation of one polypeptide‐b‐PEO copolymer, a novel multi‐responsive polypeptide‐based vesicle (polypeptidosome) presents the combined sensitivity of multiple physiological and clinic‐related stimuli, and both morphology and size of the polypeptidosome are changed during the triggered process. The designer polypeptide has unique structures composed of 1) light‐responsive o‐nitrobenzyl groups, 2) oxidizable thioether linkers, 3) photo‐caged redox thiol groups on parent poly(L‐cysteine), and 4) tunable conformation, which enable the polypeptidosome to have a peculiar multi‐response. The anticancer drug doxorubicin can be released in a controlled or on–off manner. The combination stimuli of UV irradiation and H₂O₂ oxidation induces a large effect and a lower IC₅₀ of 3.80 μg doxorubicin (DOX) equiv/mL compared to 5.28 μg DOX equiv/mL of individual H₂O₂ trigger.

     

Investigation of influential factors on the purification of zone‐refined germanium ingot

Zone refining is one of the most important procedures to purify germanium crystals for the fabrication of detectors in our laboratory. In order to properly zone refine high‐purity germanium crystals, it is important to develop perfect cleaning procedures for raw materials, quartz tubes, and the containers holding raw materials. Additionally, vacuum levels, container types, the correct combination of ambient gases, the speed of zone travel, and the ratio of ingot length to molten zone length, all need to be carefully studied in order to obtain the best results possible. In this work, we investigate a number of influential factors in perfecting high‐purity germanium crystal growth, specifically: cleaning procedures, boat composition, vacuum levels in the chamber, zone travel speed, and the ratio of ingot length to molten zone length. Using the van der Pauw Hall technique, we were able to measure the electrical properties of zone‐refined ingots and analyze the origin and distribution of three main impurity elements (boron, aluminum and phosphorus) thereby allowing us to study potential contamination sources. After detailed analysis on the various influential factors, we were able to optimize the zone‐refining procedures.     

Optical properties of MgxZn1−xO thin films deposited on silicon and sapphire substrate by rf magnetron sputtering

The index dispersion at UV–VIS range for polycrystalline Mg_xZn_1−xO films on silicon with different Mg concentration was obtained by spectroscopic ellipsometry (SE) method. It decreases with the increase of the Mg content. Above the relative peak wavelength, they are well fitted by the first-order Sellmeier relation. The band gap of films on sapphire of different Mg content was determined from transmission measurements. Photoluminescence (PL) illustrated that for Mg_xZn_1−xO films every PL peak corresponded to a special excitation wavelength. The wavelength of the PL peak was proportional to the special excitation wavelength. A strong peak was obtained in the blue band for the films due to the large amount of oxygen vacancies caused by excess Zn and Mg atoms, while weak peak at ultraviolet band.     

Novel Image Optimization Method for Joint Photoacoustic Tomography

The distribution of speed of sound （SOS） in biomedical tissue and delay compensation （DC） have significant impact on the image quality of photoacoustic tomography （PAT）. When imaging human peripheral joints, using fixed SOS and DC can only ensure that the reconstructed images are focused in a limited depth range, whereas they are defoeused at other depths, which cause severe artifacts and blurring. In this work, a linear-DC based reconstruction approach is proposed to focus the whole PAT image region. It is proved by two in vivo experiments that, compared with traditional delay-and-sum back projection algorithms, the proposed method can effectively optimize the image quality of articular tissues in PAT.     

Colouration mechanism of underglaze copper‐red decoration porcelain (AD 13th–14th century), China

Underglaze copper‐red decoration, i.e. the copper colourant used to paint diversified patterns on the surface of a body and then covered by transparent glaze and fired at high temperature in a reductive firing environment, is famous all over the world. However, the red colouration mechanism generated by underglaze copper remains unclear. In particular, the fact that the edges of the red patterns are orange has been ignored in previous research. Here, non‐destructive analysis has been carried out on a precious fragment of early underglaze red porcelain using synchrotron radiation X‐ray fluorescence, X‐ray absorption near‐edge spectroscopy (XANES) and reflection spectrometry techniques. The results suggest that the copper content in the red region is higher than that in the orange region, and other colour generation elements do not have obvious content difference, indicating that the colour generation effect of the underglaze red product is related to the copper content. XANES analysis shows that the valence states of copper in the red and orange regions are similar and metal copper contributes to their hues. The results of reflection spectrometry demonstrate that tiny orange hues could be attributed to the Mie scatting effect. Therefore, light‐scattering effects should be considered when researching the colouration mechanism of underglaze red.     

Collateral circulation prevents masticatory muscle impairment in rat middle cerebral artery occlusion model

The rat suture middle cerebral artery occlusion (MCAO) is a frequently used animal model for investigating the mechanisms of ischemic brain injury. During suture MCAO, transection of the external carotid artery (ECA) potentially restrains blood flow and impairs masticatory muscle and other ECA‐supported territories, consequently influencing post‐operation animal survival. This study was aimed at investigating the effect of ECA transection on the hemodynamic alterations using a novel synchrotron radiation (SR) angiography technique and magnetic resonance imaging in live animals. Fifteen male adult Sprague‐Dawley rats were used in this study. Animals underwent MCAO, in which the ECA was transected. SR angiography was performed before and after MCAO. Rats then underwent magnetic resonance imaging (MRI) to detect the tissue lesion both intra‐ and extra‐cranially. Animals with SR angiography without other manipulations were used as control. High‐resolution cerebrovascular morphology was analyzed using a novel technique of SR angiography. The masticatory muscle lesion was further examined by hematoxylin and eosin staining. MRI and histological results showed that there was no masticatory muscle lesion at 1, 7 and 28 days following MCAO with ECA transection. In normal condition, the ECA and its branch external maxillary artery were clearly detected. Following ECA transection, the external maxillary artery was still observed and the blood supply appeared from the anastomotic branch from the pterygopalatine artery. SR angiography further revealed the inter‐relationship of hemisphere extra‐ and intra‐cranial vasculature in the rat following MCAO. Transection of the ECA did not impair masticatory muscles in rat suture MCAO. Interrupted blood flow could be compensated by the collateral circulation from the pterygopalatine artery.