小型无人机C／G复合材料尾撑杆的研制

本文介绍了复合材料管件（无人机尾撑杆）的结构与铺层设计、基体树脂选择和成型工艺以及性能测试等内容。     

建筑装饰陶瓷饰面砖的应用与发展

分析建筑装饰陶瓷饰面砖的装饰特点，针对陶瓷饰面砖自重大、易脱落、装饰效果受装饰施工技术及质量的影响等问题，提出陶瓷饰面砖的发展应注重适应装饰施工技术及应用而进行产品的技术创新。     

超分子化学与环糊精

超分子化学是上世纪八十年代末兴起的一门新兴边缘学科,它的发展为各个学科的研究和新技术、新材料的研发开拓了一个崭新的领域。环糊精是超分子化学的重要研究内容之一。本文对环糊精的来源和分子结构特点作了简单介绍,论述了环糊精及其衍生物任超分子化学领域中的地位和作用,显示出超分子化学及环糊精研究和应用的无限潜力。     

5000t/d熟料生产线的调试与生产

1概况天瑞集团汝州水泥有限公司5000t/d新型干法水泥熟料生产线,是规划两条线中的第二条生产线,年产熟料160万吨,包括从原料进厂破碎至水泥熟料出厂的一条完整的5000t/d水泥熟料生产线。工程总投资2.85亿元,从生料均化库桩基开始到生产线一次点火投产仅用了10个月另2天。无论从     

Adjusting Pt Nanoparticle Size on SBA-15 by a Sol-Immobilisation Method Towards Naphthalene Hydrogenation

Regularly dispersed Pt particles on SBA-15 supported catalysts were synthesized with a Pt loading of 5 wt% by a sol-immobilisation method, wherein various Pt particle sizes within 1–5 nm were finely controlled via the adjustment of the addition amount of polyvinyl alcohol (PVA). A high PVA/Pt ratio of the initial solution tended to generate small Pt particles on the SBA-15 support due to intense protection against Pt particle aggregation. In addition, the effect of Pt particle size on naphthalene hydrogenation was investigated in terms of catalytic performance. Compared with the performance of other catalysts with Pt particle sizes greater or less than 3.5 nm, Pt nanoparticles with sizes centered at 3.5 nm exhibited excellent catalytic performance towards decalin. This excellent catalytic performance was mainly attributed to a suitable ratio of the edge sites to flat sites on these Pt nanoparticles, benefitting the rapid adsorption of naphthalene and dissociation of hydrogen.

Graphical Abstract

The Pt/SBA-15 catalysts were prepared by sol-immobilisation method. The highest performance was attributed to the Pt-nanoparticles with suitable flat/edge sites ratio.

     

玉米浆为有机氮源的L-乳酸发酵的研究

利用细菌厌氧发酵生产L-乳酸,以降低L-乳酸生产成本为主要目的,实验以玉米浆为有机氮源,以硫酸铵为主要无机氮源,研究了不同接种量对发酵过程的影响;并就以玉米浆替代酵母粉、豆粕水解液、生物素为有机氮源的L-乳酸发酵进行了对比研究实验,实验证明了玉米浆做为有机氮源用于L-乳酸发酵的可行性。在保证生产能力的同时,使用玉米浆为有机氮源对进一步降低L-乳酸生产成本,减少玉米浆对环境的污染进行了探索。     

耐热性橡胶配合技巧(上)

介绍了耐热橡胶的等级划分，各种橡胶的使用温度和性能特点，及13种橡胶（天然橡胶、聚氨酯橡胶、丁苯橡胶、顺丁橡胶、氯丁橡胶、丁腈橡胶、氯磺化聚乙烯橡胶、氯醚橡胶、丁基橡胶、乙丙橡胶、丙烯酸酯橡胶、氟橡胶、硅橡胶）的78个耐热配方实例，并对配方做了简要说明。所述配方可基本满足橡胶材料从A～I级9个耐热等级的不同要求。     

一种基于深度卷积网络的鲁棒头部姿态估计方法

针对头部姿态估计方法受特征提取限制导致姿态估计效果不佳的问题,提出使用深度卷积网络自动学习有效特征并进行分类的头部姿态估计方法。首先,利用DCNN非线性映射和自动提取图像结构信息的能力,设计一个深度卷积网络实现对姿态鲁棒特征的提取;然后再将提取的特征用于分类器训练并最终实现头部姿态估计。在Pointing’04和FacePix数据库上的测试结果表明,本文设计的深度卷积网络能有效的进行特征学习,避免了人工设计特征的不足,与现有的基于人工设计特征方法相比,本文方法在两个数据库上达到的预测平均绝对误差分别为4.05〫和2.04〫,充分证实了本文算法的稳定性和可靠性。     

Spectral and complexity analysis of scalp EEG characteristics for mild cognitive impairment and early Alzheimer's disease

Amnestic mild cognitive impairment (aMCI) often is an early stage of Alzheimer's disease (AD). MCI is characterized by cognitive decline departing from normal cognitive aging but that does not significantly interfere with daily activities. This study explores the potential of scalp EEG for early detection of alterations from cognitively normal status of older adults signifying MCI and AD. Resting 32-channel EEG records from 48 age-matched participants (mean age 75.7 years)—15 normal controls (NC), 16 early MCI, and 17 early stage AD—are examined. Regional spectral and complexity features are computed and used in a support vector machine model to discriminate between groups. Analyses based on three-way classifications demonstrate overall discrimination accuracies of 83.3%, 85.4%, and 79.2% for resting eyes open, counting eyes closed, and resting eyes closed protocols, respectively. These results demonstrate the great promise for scalp EEG spectral and complexity features as noninvasive biomarkers for detection of MCI and early AD.     

Catalytic activities and properties of mesoporous sulfated Al2O3–ZrO2

Mesoporous sulfated Al₂O₃–ZrO₂ (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher Al₂O₃ content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption, transmission electron microscopy (TEM), ²⁷Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed desorption of ammonia (NH₃-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al₂O₃–ZrO₂ samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed reactions.