基于海明神经网的电压-无功功率自动调节理论的研究

本文引入了人工神经网络（海明网络），利用状态分类来解决变电站电压-无功功率双参数控制中的边界问题。     

关于Lagrange插值多项式导数的逼近

设Ｌｎ（ｆ，ｘ）为ｆ（ｘ）的Ｌａｇｒａｎｇｅ插值多项式，给出了Ｌｎ（ｆ，ｘ）的ｋ阶导数对ｆ（ｋ）（ｘ）的整体逼近阶和点态逼近阶     

Cosserat介质理论与连续介质理论的耦合计算方法

在Ｃｏｓｓｅｒａｔ介质理论与连续介质理论的基础上．建立了适合于含断层的层状岩体弯曲变形破坏稳定分析的有限元计算方法，算例分析表明．本文提出的方法是正确的．     

High-spectral-resolution lidar with iodine-vapor filters: measurement of atmospheric-state and aerosol profiles

A high-spectral-resolution lidar can measure vertical profiles of atmospheric temperature, pressure, the aerosol backscatter ratio, and the aerosol extinction coefficient simultaneously. We describe a system with these characteristics. The transmitter is a narrow-band (FWHM of the order of 74 MHz), injection-seeded, pulsed, double YAG laser at 532 nm. Iodine-vapor filters in the detection system spectrally separate the molecular and aerosol scattering and greatly reduce the latter (-41 dB). Operating at a selected frequency to take advantage of two neighboring lines in vapor filters, one can obtain a sensitivity of the measured signal-to-air temperature ratio equal to 0.42%/K. Using a relatively modest size transmitter and receiver system (laser power times telescope aperture equals 0.19 Wm(2)), our measured temperature profiles (0.5-15 km) over 11 nights are in agreement with balloon soundings to within 2.0 K over an altitude range of 2-5 km. There is good agreement in the lapse rates, tropopause altitudes, and inversions. In principle, to invert the signal requires a known density at one altitude, but in practice it is convenient to also use a known temperature at that altitude. This is a scalable system for high spatial resolution of vertical temperature profiles in the troposphere and lower stratosphere, even in the presence of aerosols.     

钒对喷熔材料性能的影响

为提高镍基和铁基合金粉喷熔层的耐磨性和耐热疲劳性能,在现有的Fe60E和Ni60A喷熔合金粉中加入1.5%～1.8%的V制成新型喷熔材料Fe60EV和Ni60AV.试验测定了Fe60EV和Ni60AV喷熔层的硬度、耐磨性和抗热疲劳性能,结果表明,含钒喷熔合金层的硬度比未加钒的喷熔合金层的高,其耐磨性和耐热疲劳性能也明显提高.在热轧卷取机衬板上的工业应用表明,喷熔Fe60EV和Ni60AV合金层后,其使用寿命分别比喷熔Fe60E和Ni60A提高30%以上.     

合理运用钢材期货有效规避市场风险

从近期金属市场和证券市场的变化来看,市场蕴藏着巨大的风险。如何有效规避来自市场价格波动风险,成为企业实现经营目标必须面对的课题。期货市场的出现为解决了这一课题提供了一个绝佳的解决途径。这使得交易双方和众多的市场参与者利用期货市     

几种低温液体液位的测量方法

介绍了8种低温液体液位的测量方法:差压法、测满阀法、液位开关法、浮子液位计法、安全阀法、温度测量法、伺服液位计法及雷达液位计法。     

Preparation and characterization of polycaprolactone-chitosan composites for tissue engineering applications

Highly porous scaffold plays an important role in bone tissue engineering, which becomes a promising alternative approach for bone repair since its emergence. The objective of this work was to blend poly (є-caprolactone) (PCL) with chitosan (CS) for the purpose of preparation of porous scaffold. A simple unique method was employed under room-temperature condition to blend the two components together without separation of two phases. The reaction leads to formation of sponge-like porous 5, 10, 15 and 20 wt% CS composites. XRD, IR and SEM were used to determine components and morphology of the composites. DSC studies indicated that the miscibility of the two components. And pore volume fractures of composites were determined by a simple method in which a pycnometer was used. The results show that CS is successfully commingled into PCL matrix, and adding CS into PCL will not damage the crystalline structure of PCL. The composite shows no signs of phase separation and presents a unique porous structure under SEM observation. The porosity of composite increased with the increase of the content of CS in the composite. The highest porosity reached to 92% when CS content increased to 20 wt%. The mechanism of formation of this unique porous structure is also discussed.     

Fast Shadow Removal Using Adaptive Multi‐Scale Illumination Transfer

In this paper, we present a new method for removing shadows from images. First, shadows are detected by interactive brushing assisted with a Gaussian Mixture Model. Secondly, the detected shadows are removed using an adaptive illumination transfer approach that accounts for the reflectance variation of the image texture. The contrast and noise levels of the result are then improved with a multi‐scale illumination transfer technique. Finally, any visible shadow boundaries in the image can be eliminated based on our Bayesian framework. We also extend our method to video data and achieve temporally consistent shadow‐free results.     

Changes in snow and glacier cover in an arid watershed of the western Kunlun Mountains using multisource remote-sensing data

Snow and glaciers in the mountain watersheds of the Tarim River basin in western China provide the primary water resources to cover the needs of downstream oases. Remote sensing provides a practical approach to monitoring the change in snow and glacier cover in those mountain watersheds. This study investigated the change in snow and glacier cover in one such mountain watershed using multisource remote-sensing data, including the Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat (Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+)), Corona, and Google Earth^TM imagery. With 10 years’ daily MODIS snow-cover data from 2002 to 2012, we used two de-cloud methods before calculating daily snow-cover percentage (SCP), annual snow-cover frequency (SCF), and annual minimum snow-cover percentage (AMSCP) for the watershed. Mann–Kendall analysis showed no significant trend in any of those snow-cover characterizations. With a total of 22 Landsat images from 1967 to 2011, we used band ratio and supervised classification methods for snow classification for Landsat TM/ETM+ images and MSS images, respectively. The Landsat snow-cover data were divided into two periods (1976–2002 and 2004–2011). Statistical tests indicated no significant difference in either the variance or mean of SCPs between the two periods. Three glaciers were identified from Landsat images of 1998 and 2011, and their total area increased by 12.6%. In addition, three rock glaciers were also identified on both the Corona image of 1968 and the Google high-resolution image of 2007, and their area increased by 2.5%. Overall, based on multisource remote-sensing data sets, our study found no evidence of significant changes in snow and glacier cover in the watershed.