Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

Titanium oxynitride (TiN_xO_y) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiN_xO_y films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm² to 7 W/cm². The maximum deposition rate occurs, as the substrate bias is −40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiN_xO_y films deposited at power densities above 4 W/cm² show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiN_xO_y films reach values as low as 0.98 g/m²-day-atm and 0.60 cm³/m²-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al₂O₃ barrier films. Therefore, TiN_xO_y films are potential candidates to be used as a gas permeation barrier for PET substrate.     

基于CAN总线的运动控制通讯系统设计

数字量驱动的运动控制要求通讯系统具有良好的实时性和可靠性。设计了一种基于CAN总线的多节点多通道的运动控制通讯系统,以FPGA为节点控制器,通过SJA1000收发运动控制数据,并行发送到各通道驱动器的数模转换器中。FPGA模块由Verilog HDL编写,通过参数传递和生成块的方法简化代码,提高系统的可移植性,移植时只需改变两个常量值即可适应各个节点不同的通道数和位宽。实验表明,通讯系统每帧耗时约120us,最高帧频可达8.5kHz,误码率低于10^-8,实时性和可靠性较好。     

Determination of Young's modulus of epoxy coated polyethylene micro-cantilever using phase-shift shadow moiré method

Young′s moduli of various epoxy coated polyethylene terephthalate (PET) micro-cantilevers were determined from the deflection results obtained using the phase-shift shadow moiré (PSSM) method. The filler materials for epoxy coatings were aluminum and graphite powders that were mixed with epoxy at various percentages. Young′s moduli were calculated from theory based on the deflection results. The PET micro-cantilever coated with aluminum-epoxy coating showed increasing value of Young′s modulus when the ratios of the aluminum-epoxy were increased. The graphite-epoxy coating on the PET micro-cantilever also showed the same trend. The experimental results also show that Young′s modulus of the graphite-epoxy coating is higher than aluminum-epoxy coating in comparison at the same mixing ratio.     

Absorption characteristics of masjid carpets

This work investigated the absorption characteristics of eight types of carpets that are especially designed and manufactured for masjids and two types of carpets pads. Measurements were carried out in the reverberation room according to ISO 354. Each type was tested three times: first when it was installed directly on the floor, second when it was installed above 5.7 mm of polyurethane foam, and last when it was installed above 10 mm of polyethylene foam. The results showed that the absorption coefficient is directly proportional to frequency and knot density. The results also demonstrated that adding pads of polyurethane or polyethylene foam increased the absorption, principally in the mid-frequency range. The effect of polyurethane foam on absorption was higher than that of polyethylene foam. Finally, the absorption coefficients of the examined carpets were found to be close to those of Muslim worshippers when they are in the position known as “standing in rows”.     

基于装备的IETM技术资料拆分模型研究

为了解决技术资料难于拆分、归类、全面展示及手册研制后期数据难于共享等问题,通过将S1000D标准与本单位装备IETM手册编制过程相结合,采用标准分析方法、规范分类原则,从分析装备技术资料来源开始,设计数据模块所对应的信息集,建立面向装备系统结构的技术资料拆分模型,使技术资料的拆分变得简单易行且更符合标准要求,保证了IETM研制的一致性,为装备全寿期提高技术信息的重用性、可维护性、共享性和实时有效性奠定基础,极大地提升了IETM手册编制效率。     

A subfringe integration method for multiple-beam Fizeau fringe analysis

Some aspects concerning the subfringe integration method in interferogram analysis have been investigated and modified. The modified algorithm, introduced in this paper, is capable of reconstructing the phase in the presence of noise or errors in carrier frequency. The subfringe integration method was applied to analyze two computer simulated patterns of equispaced Fizeau fringes using N bucket integration. Also, it is used to analyze the multiple-beam Fizeau fringe. The refractive index profile of polyethylene fiber is obtained by using two methods, subfringe integration method, and Fourier transform method. A comparison between the obtained results using the maintained methods is presented.     

Shear Thickening Fluids Based on Additives with Different Concentrations and Molecular Chain Lengths

将二氧化硅颗粒和不同分子链长添加剂颗粒分散到聚乙二醇分散介质中制得剪切增稠液样品,研究了添加剂的不同含量和不同分子链长对剪切增稠液流变性能的影响. 对其流变特性的研究表明,随着添加剂含量的增加和分子链长的增长,样品的剪切增稠效应增强明显,并用大粒子簇的形成对增强机理给出了合理的解释.     

铜离子印迹环氧树脂基整体柱的制备及性能

以铜离子为印迹物,二乙基三胺为固化剂,聚乙二醇(PEG-2000)为致孔剂,按一定比例与环氧树脂混合后在无扰动模式下聚合。反应结束后除去致孔剂和印迹离子成功地得到了一种铜离子印迹的大尺寸环氧树脂基聚合物整体柱。以此作为固相萃取柱,结合原子吸收光谱建立了用于水溶液中铜离子高选择性的富集分离测定方法。详细研究了介质酸度、吸附容量、吸附选择性、分析精密度和准确度等内容,结果满意。     

Physico-chemical aspects of polyethylene processing in an open mixer. Part 25: Mechanisms of aldehyde and carboxylic acid formation

Aldehydes and acids can be formed in numerous reactions in oxidizing polyethylene melts. Significant amounts of aldehydes result from β-scission of alkoxy radicals that are formed on bimolecular hydroperoxide decomposition. There are also large amounts of aldehydes expected from acid-catalyzed decomposition of allylic hydroperoxides as soon as enough acids have accumulated for efficient catalysis. There are difficulties in explaining the formation of aldehydes at a constant rate in sufficient amount for explaining the experimental data. There are much less difficulties with the constant rate of carboxylic acid formation. The α,γ-keto-hydroperoxides that are formed on chain propagation might account for the bulk of the acids formed at a constant rate.The foremost problems with the acids pertain to their formation at increasing rates in the initial as well as in the advanced stages. Formation and decomposition of α,β-di-hydroperoxides and α,γ-di-hydroperoxides is a possibility in this respect. Similarly, α,β-keto-hydroperoxides might be formed on peroxidation in the α-position to ketone groups in the advanced stages. There are considerable difficulties in elucidating the exact role of the aldehydes that are usually seen as the main precursors of the acids. Although there are many possibilities for transformation of aldehydes into acids, the free radical mechanisms envisaged usually have considerable disadvantages. These disadvantages result essentially from fast decarbonylation of acyl radicals and even faster decarboxylation of acyl-oxy radicals. Direct transformation of peracids into acids on reaction with double bonds is always a possibility. Moreover, in the low temperature range (150-160 °C) where hydroperoxides are accumulating, direct reaction of aldehydes with primary and/or secondary hydroperoxides will also yield acids.     

聚乙二醇类表面活性剂对硅表面无电沉积Ag膜光滑作用研究

应用原子力显微镜技术及开路电位～时间谱技术,研究了非离子表面活性剂聚乙二醇2000,6000,20000对硅(100)表面无电沉积银膜的光滑作用.实验表明硅(100)表面无电沉积银的光滑程度以及镀层的质量均随聚乙二醇聚合度的增加而变好.