Enhancing textile ink-jet printing with chitosan

Following on from previous research, the possibility of using chitosan in preparing the pretreatment print paste for textile ink-jet printing was investigated but the final colour was not as good as expected. In this study, chitosan was applied separately on cotton fabric for ink-jet printing. A two-bath method was proposed and it was confirmed that a better colour yield was achieved with this method. However, the use of chitosan reduced the tensile strength of the ink-jet printed fabric slightly.     

Electrical properties of (Bi3.5La0.5)Ti3O12 thin-films prepared by liquid source misted chemical deposition

The ((Bi_3.5La_0.5)Ti₃O₁₂(BLT) thin-films used in this study were fabricated on a Pt(111)/SiO₂/Si(100) substrate by a Liquid Source Misted Chemical Deposition (LSMCD) technique. X-ray diffraction patterns showed that the BLT films were crystallized and no other phases were observed when annealed above 650 ‡C. Grain size and remnant polarizations increased with increase in the annealing temperature, while leakage current densities decreased. The remnant polarizations (Pr) increased from 2.0 to 4.8 and 19.0 μC/cm2 with increase in the annealing temperature from 650 to 700 and 750 ‡C, respectively. The BLT films annealed at 700 ‡C in O₂ showed a good fatigue resistance of reduced polarization by 10% after 10⁹ switching cycles when 9 V of bipolar voltage was applied at a frequency of 40 kHz.     

一种基于D-S 和ARIMA 的多模型软测量方法

针对传统软测量方法存在的预测性能差、融合能力低等缺点, 提出一种基于证据理论(D-S) 合成规则和差分自回归滑动平均(ARIMA) 模型的多模型软测量方法. 首先利用自适应模糊核聚类方法和最小二乘支持向量机建立多个子模型; 然后利用D-S 合成规则构造的概率分配函数作为权值因子, 对子模型输出进行融合以得到多模型的输出; 最后结合ARIMA 模型对静态多模型输出进行动态校正. 仿真研究与工业应用的结果表明, 所提出的方法具有良好的预测性能和融合能力.

     

Polyimide foams with ultralow dielectric constants

To explore ultralow dielectric constant polyimide, the crosslinked polyimide foams (PIFs) were prepared from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA), 4,4′‐oxydianiline (ODA), and 2,4,6‐triaminopyrimidine (TAP) via a poly(ester–amine salt) (PEAS) process. FTIR measurements indicated that TAP did not yield a negative effect on imidization of PEAS precursors. SEM measurement revealed the homogeneous cell structure. Through using TAP as a crosslinking monomer, the mechanical properties of PIFs could be improved in comparison with uncrosslinked BTDA/ODA based PIF. The crosslinked PIFs still exhibited excellent thermal stability with 5% weight loss temperatures higher than 520°C. In the field with frequency higher than 100 Hz, the dielectric constants of the obtained PIFs ranged from 1.77 to 2.4, and the dielectric losses were smaller than 3 × 10^?2 at 25–150°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1734–1740, 2006     

Thermal and mechanical properties of the polymers synthesized by the sequential polymerization of propylene and 1‐hexadecene

The block copolymer of poly(1‐hexadecene) (PHD) and polypropylene (PP) was effectively synthesized by the sequential polymerization of propylene and 1‐hexadecene by using highly isospecific TiCl₃/Cp₂Ti(CH₃)₂ (Cp = cyclopentadienyl). The block copolymers had two separate melting temperatures of constituent blocks. The modulus of PHD–PP block copolymer was enhanced as the content of sequentially polymerized PP block was increased. The elongation at break showed positive deviation at the intermediate compositions from the simple additive values of constituent homopolymers. Shape memory effect which utilizes the crystalline PHD block as a reversible phase and the crystalline PP block as a fixed structure was examined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1709–1715, 2002; DOI 10.1002/app.10551     

The participation of block copolymers in the increase in the number of tie molecules

Three-block copolymers polyamide-block-polyX-block-polyamide (where X is styrene, ethylene-co-1-butene, and others) are able to improve substantially the toughness of poly(ϵ-caprolactam). Outer blocks of these copolymers are able to take part in folding lamellae of semi-crystalline polyamide, inner blocks are not. They operate as a spacer, meaning that the end blocks of copolymers capable of folding become parts of different lamellae, or that the unfoldable part of a block copolymer is pushed out of a folding lamella with a certain probability of the remaining outer block taking part in folding another lamella. This increases the number of tie-molecules.     

An investigation on wear behavior of UHMWPE/carbide composites at elevated temperatures

Ultra-high molecular weight polyethylene (UHMWPE) is extensively used in frictional applications due to its advanced wear resistance. This advanced polymer is reinforced with hard particulate fillers for further developments against wear conditions. Since elevated temperatures prevail in the service conditions, wear behavior of UHMWPE composites is an important issue for the engineering applications. In the present work, UHMWPE-based composites including silicon carbide (SiC) fillers were fabricated in a compression molding chamber. In the specimen preparation stage, molding pressure, filler amount, and filler particle size were varied to investigate the influence of these variables. Upon deciding the optimum parameters from the wear tests conducted at room temperature, the wear experiments were repeated for the optimum specimen at elevated temperatures, such as 40 and 60°C. According to the results, the wear behavior of the SiC/UHMWPE composites is heavily changed by the effect of elevated temperature. Adhesive effect is pronounced at elevated temperatures while the wear characteristics possess the abrasive effect in the sliding path. In addition, the composites exhibit an accelerated material loss as temperature increases during the frictional system.     

FE approach and experiments for an axisymmetric micro-yoke part forming using grain element and grain boundary element

Until present, an axisymmetric yoke part of electro-magnetic micro-speaker/receiver had manufactured by machining through the material’s removal. However, this machining process have some problems such as long production time, high precision of tool and costs. In this study, a program based on finite element method developed to establish milli-structure forming technology for micro-yoke component, one of the key parts in the multi-functioned micro-speaker/receiver. This developed program is applied for the milli-part forming in order to replace the machining process of micro-yoke. A new numerical approach is proposed to simulate intergranular milli-structure in forming the miniature yoke, in which grain elements and grain boundary elements are introduced. The results of the finite element analysis for micro-yoke part are confirmed by a series of experiments.     

新型咪唑啉衍生物油田注水缓蚀剂的研究

使用长链脂肪酸、多胺、甲醛和三氯化磷等为原料合成了咪唑啉有机膦酸类缓蚀剂。在模拟油田注水条件下，采用静态挂片、极化曲线和交流阻抗等测试方法评价了缓蚀剂的缓蚀性能，并对缓蚀剂的成膜机理进行了一些研究与探讨。     

Formulating the template ILP consistency problem as a constraint satisfaction problem

Inductive Logic Programming (ILP) deals with the problem of finding a hypothesis covering positive examples and excluding negative examples, where both hypotheses and examples are expressed in first-order logic. In this paper we employ constraint satisfaction techniques to model and solve a problem known as template ILP consistency, which assumes that the structure of a hypothesis is known and the task is to find unification of the contained variables. In particular, we present a constraint model with index variables accompanied by a Boolean model to strengthen inference and hence improve efficiency. The efficiency of models is demonstrated experimentally.