在线社交网络上学生数量与出生年月的关系研究

以在线社交网络“人人网”上重庆邮电大学1657名大学生为研究对象,研究在社交网络上学生的出生年月对学生数量的影响.研究结果表明入学年龄限制对在校大学生数量有一定影响,10、11、12月这三个月出生的学生最多;学生的出生年份对使用“人人网”的学生数量的影响较大,1985年到1990年这6年出生的学生占总学生数的93.7％,而1991到1995年出生的大学生则大量使用微博,说明学生出生年份对其使用社交网络平台具有明显的时代特征.     

复杂铝合金零件镀银工艺改进

介绍了复杂铝合金零件镀银工艺,分析了影响铝合金电镀层质量的因素,通过试验改进了铝合金电镀工艺,在常规二次浸锌工艺中增加了电镀锌,采用浸锌电镀锌联合处理法提高了复杂铝合金零件镀银的结合力。给出了工艺流程及各工序溶液配方和相关参数,并提出了相应的操作要点。介绍了生产过程中易出现的问题及解决办法。利用划格法和热震法检验了镀层的结合强度。测试结果表明:采用新工艺加工的零件达到了结合力的要求。     

铝合金化学镀镍工艺研究与应用

报道一种在铝合金元件上实施化学镀镍的工艺方法。该方法包括在改进的锌酸 溶液中经二闪浸锌处理后,以碱性化学镀镍作底层,然后进行酸性化学镀镍,能在铝合金（ＬＹ１２ｃｚ、ＬＤ３１等）表面获得光亮的、具有优异附着力和良好的防腐蚀性能及其综合物理、化学特性的化学镀镍（Ｎｉ－Ｐ）层。     

美国数字红利频谱释放政策研究与启示

数字红利频谱释放工作因涉及面广、情况复杂,近几年受到社会的广泛关注.首先结合地面广播电视数字化进程,概述了美国数字红利频谱释放情况,然后分别对美国700 MHz、600 MHz频段频谱释放政策、进展以及成果等进行梳理和研究,总结提炼出“依法行政、强制推进、市场机制、稳妥有序、自愿协商”的方法与经验,最后结合我国使用现状,提出相关建议.     

Preprogramming Floating Time of Liquid Marble

Non-sticking droplets wrapped with fine hydrophobic particles, namely liquid marbles, can be transported both on solid and water pool without an undesired spill of the inner encapsulated liquid. While the stimuli-responsive release of the inner liquid in the target area is proposed, the time-programmed release is not yet achieved. Herein, the hydrophobicity of nanoclay is modulated via a catalyst-free 1,4-conjugate addition reaction to form liquid marbles. This nanoclay liquid marble is robust and stable in air but collapses on the liquid pool with a specific lifetime. The lifetime of the liquid marble can be modulated over seconds to hours scale depending on the selection of chemically modulated wettability of the nanoclay. The critical mechanism of lifetime modulation is responsible for controlling the coalescence kinetics between the water pool and inner liquid by nanoclays’ high diffusion length and chemically varied water spreading potential. The NC liquid marble's programmable lifetime to ‘time-bomb’ type drug release and cascade chemical reaction is applied—without requiring any external intervention.     

微波集成二极管倍频组件

本文首先对微波集成二极管倍频器作了简单介绍,并以微波集成17次倍频组件为例,论述多次倍频器的原理、设计、电路结构和测试调整方法.     

混响室条件下的辐射敏感度测试新方法

提出了一种基于统计平均思想的新的辐射敏感度测试方法,在大量实验的基础上验证其可靠性。两种工作模式分别采用位于测试区域内的接收天线在统计平均时间内接收环境场的平均值和所有步进位置测试结果的平均值作为最终测试结果。实验结果表明该方法测试过程简单,能够得到给定设备在任意敏感频点的辐射敏感度阈值,且具有良好的测试可重复性。将国际电工委员会(IEC)颁布的IEC61000-4-21第二版新标准与旧版本中关于步进模式最少独立采样位置的数量做了简要对比,通过实验数据验证了新版本的测试结果。     

Effect of microwave treatment on the cooking and macronutrient qualities of pulses

The effect of microwave treatment to reduce the cooking times of five pulses, namely red lentil, chickpea, pigeon pea, mung bean, and pinto bean, were determined in this study. Pulses from 10 to 18% moisture contents were treated using 400 to 600 W microwaves for 14 to 56 s. The cooking times of microwave-treated pulses were significantly lower than that of the control samples. The lowest cooking time was observed for 18% moisture content chickpea and pigeon pea treated with 600 W for 56 s. The Fourier transform mid-infrared spectra in both lipids and fingerprint regions showed the macronutrients differences among the five pulses. Major changes were observed in the amide I region of microwave treated pulses. This effect of microwave treatment was higher in red lentil, chickpea, and mung bean than in pigeon pea and pinto bean at 10% moisture content. At 18% moisture content, the change of β-sheets to aggregates was observed in all pulses due to microwave treatment.     

Juice of New citrus hybrids (Citrus clementina Hort. ex Tan.×C. sinensis L. Osbeck) as a source of natural antioxidants

Fruit juices of pigmented and non-pigmented new citrus hybrids obtained by crossing clementine cv. Oroval with different cultivars of blood oranges were analysed to determine parameters related to fruit quality (total soluble solids titratable acidity, pH), and the content of ascorbic acid, total phenolics, flavanones, anthocyanins and phenolic acids. Antioxidant properties were evaluated by oxygen radical absorbance capacity (ORAC), and inhibition of induced linoleic acid peroxidation (InLAP) assays. The results of this study show that some hybrids with high antioxidant activity owing to considerable polyphenol content may be considered rich sources of phytochemicals. The OTA 9 hybrid was shown to be richest in polyphenols, suggesting that consumption of OTA 9 fruit or juice could be useful in health promotion and a disease-preventing diet. Moreover, the juice of this hybrid could be used as raw material to produce antioxidant ingredients for dietary, pharmaceutical, or cosmetic purposes.     

Iron encapsulated microstructured emulsion-particle formation by prilling process and its release kinetics

Encapsulation of functional components is commonly used to protect them from the environment, or to control their release. In the present study, iron is used as a model nutrient that is encapsulated in water-in-oil emulsion. Fat based emulsion particles are produced using that emulsion through prilling process using twin fluid atomizers. The particles are characterized in terms of size and size distribution, and their internal structure is investigated by cryogenic scanning electron microscopy (cryo-SEM). The iron release kinetics through the fat matrix of the emulsion particles in an in vitro gastric system (pH ≈ 2.0) is described by the second order kinetics. An empirical correlation of the release kinetics rate constant is proposed as a function of the viscosity ratio of dispersed to continuous phase, mean particle size, and shelf-life of the particles. It is seen that the release kinetics can be controlled by choosing particle size and thickener concentration.