Effects of the organometallic coupling agents on adhesion of the carbon fiber–BMI composites

In order to increase the chemical bonding force between fiber and resin, several kinds of organometallic coupling agent (such as titanate, zirconate, and zircoaluminate) were chosen and added in the BMI resin formulation, which possess the same solvent system with those coupling agents. The DSC analysis technique was used to find the best curing condition, and TGA was used to investigate the thermal stability property of the best curing condition. For the purpose of analyzing the bonding structure, ESCA surface element analysis techniques was applied in this study. Beside that, the mechanical properties of tensile, flexural, and short-beam shear strengths were measured for the effect of adding coupling agents, and the SEM of fracture surfaces were taken to study the fractural analysis. The results showed that composites with the application of organometallic coupling agents of [RO–Ti(OX–R′NH₂)₃] structure in the treatment of BMI resin were highly thermal stable. Also, it was shown that the mechanical strengths of composites fabricated by pretreatment of the carbon fibers with coupling agents were higher than those fabricated by adding coupling agents in resins, but there was no obvious improvement of mechanical properties with higher concentration of coupling agents. However, the SEM showed that the adhesion between fiber and resin can actually be improved by adding proper amount of coupling agents in the BMI resin formulation.     

Development of 1D model for the analysis of heat transport in cylindrical micro combustors

A 1D flame model was developed to analyze the heat transport occurring in the cylindrical micro combustors. The one-step global reaction mechanisms were employed for three fuel–air mixtures (H₂–air, CH₄–air and C₃H₈–air) to account for the difference of fuel property in terms of the kinetics. The effects of various parameters such as the combustor size, fuel property, fuel–air equivalence ratio and unburned mixture temperature on the heat loss ratio (defined as Q_l/Q_in) and the heat recirculation ratio (defined as Q_recir/Q_l) were investigated. The results indicated that these parameters have significant effects on the two ratios, and therefore should be carefully managed in order to achieve efficient and stable combustion. After comparing the results of different fuel–air mixtures, it is concluded that hydrogen is superior to methane and propane as the fuel for micro combustion engines owing to its higher flame temperature and thinner flame thickness, which favors the reduction of heat loss from the flame zone.     

Functional acrylic acid as stabilizer for synthesis of smart hydrogel particles containing a magnetic Fe3O4 core

This paper reports a novel method to synthesize magnetic, stimuli-sensitive latex nanoparticles made with magnetite/poly(N-isopropylacrylamide-co-acrylic acid) (Fe₃O₄/P(NIPAAm-co-AAc)). To form a stabilized suspended core, iron oxide (Fe₃O₄) was functionalized with AAc such that further polymerization with NIPAAm and AAc monomers could occur. The P(NIPAAm-co-AAc) shell layer exhibited thermosensitive properties. The inclusion of Fe₃O₄ into the latex nanoparticles was confirmed using transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, thermogravimetric analyzer (TGA), and superconducting quantum interference device magnetometer. The NIP–(AAc2.6–Fe) latex nanoparticles contained 2.25% Fe₃O₄ (by weight), as determined by TGA analysis. The particle diameters measured approximately 160–240 nm with a lower critical solution temperature of 35 °C. These novel magnetic stimuli-responsive latex nanoparticles have potential applications in numerous fields, such as catalyst supports, protein immobilization, cancer therapy, target drug delivery systems, and other biomedical applications.     

丁腈橡胶、腰果油改性酚醛树脂的研究

以丁腈橡胶粉和腰果油改性酚醛树脂为改性剂，通过对多种原料、橡胶助剂、摩擦性能调节剂的研究和配方筛选，制得高性能载重汽车刹车片内衬材料。该材料磨耗低、抗冲击强度高、硬度和摩擦系数适中、高温抗热衰退明显，生产过程中可省去投资大、能耗高的密炼工艺，具有重要的工业价值。     

Preparation and UV property nickel nanoparticles （〈10 nm） of size-controlled monodisperse by reductive method

Nickel nanoparticles (<10 nm) were successfully synthesized using a reductive method of nickel chloride with sodium borohydride in the ethanol/poly- vinylpyrrolidone (PVP) system. The effects of three factors, such as the concentration of the nickel ions, the time of reaction, and the amount of PVP (surfactant), were discussed. The possible growth process of the particles and optimum reactive conditions was also investigated. The result of transmission electron microscopy (TEM) reveals that these nickel nanoparticles are spherical. The average diameter could be controlled as 2-5 nm under selected conditions. High-resolution TEM and energy-dispersive spectroscopy results indicates that the nickel nanoparticles are pure. The UV-visible light absorption spectrum shows that the peaks of nickel nanoparticles moves toward the short wavelength along with the decrease of sizes.     

水玻璃-硅溶胶复合型壳的应用

水玻璃、硅溶胶复合型壳，表面层应用硅溶胶锆英粉涂料，用来生产精铸件，尤其是高合金钢铸件，其表面粗糙度可达3．2，比水玻璃型壳的精铸件表面粗糙度参数值有所降低，约低1～1．5级，尺寸精度也有所提高。     

Recent Developments in Shaped Charge Technology

Shaped-charge principles, including analytical work, computer-code simulations, and experimental results, are reviewed. It is assumed that the reader has a basic understanding of the functioning of shaped charges, and emphasizes developments in recent years. The survey is divided into four sections: Liner Collapse, Jet Formation, Jet Breakup, and Target Penetration. Only traditional shaped charges are covered; kinetic-energy penetrators and self-forging-fragment warheads are not included. Ninety-nine references are cited.     

The Dipeptidyl Peptidase-4 Inhibitor Linagliptin Ameliorates Endothelial Inflammation and Microvascular Thrombosis in a Sepsis Mouse Model

The pathophysiology of sepsis involves inflammation and hypercoagulability, which lead to microvascular thrombosis and compromised organ perfusion. Dipeptidyl peptidase (DPP)-4 inhibitors, e.g., linagliptin, are commonly used anti-diabetic drugs known to exert anti-inflammatory effects. However, whether these drugs confer an anti-thrombotic effect that preserves organ perfusion in sepsis remains to be investigated. In the present study, human umbilical vein endothelial cells (HUVECs) were treated with linagliptin to examine its anti-inflammatory and anti-thrombotic effects under tumor necrosis factor (TNF)-α treatment. To validate findings from in vitro experiments and provide in vivo evidence for the identified mechanism, a mouse model of lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome was used, and pulmonary microcirculatory thrombosis was measured. In TNF-α-treated HUVECs and LPS-injected mice, linagliptin suppressed expressions of interleukin-1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) via a nuclear factor-κB (NF-κB)–dependent pathway. Linagliptin attenuated tissue factor expression via the Akt/endothelial nitric oxide synthase pathway. In LPS-injected mice, linagliptin pretreatment significantly reduced thrombosis in the pulmonary microcirculation. These anti-inflammatory and anti-thrombotic effects were independent of blood glucose level. Together the present results suggest that linagliptin exerts protective effects against endothelial inflammation and microvascular thrombosis in a mouse model of sepsis.     

Combining neural networks and genetic algorithms for optimising the parameter design of the inter-metal dielectric process

An inter-metal dielectric (IMD) is deposited between metal layers to provide isolation capability to a device and separate the different metal layers that are unnecessary in the conduction of electricity. Owing to the complicated input/response relationships of the IMD process, the void problem results in electric leakage and causes wafer scraping. In the current study, we combined neural networks, genetic algorithms (GAs) and the desirability function in order to optimise the parameter settings of the IMD process. Initially, a backpropagation (BP) neural network was developed to map the complex non-linear relationship between the process parameters and the corresponding responses. Moreover, the desirability function and GAs were employed to obtain the optimum operating parameters in respect to each response. The implementation of the proposed approach was carried out in a semiconductor manufacturing company in Taiwan, and the results illustrate the practicability of the proposed approach.     

Interface characterizations of diamond-coated tools by scratch testing and simulations

In this study, micro-scratch tests were conducted on diamond-coated tungsten-carbide substrates to investigate coating adhesion. During the scratch testing, high intensity acoustic emission (AE) signals can be clearly detected when the coating delamination occurs. It is also found that the tangential force increase gradually with the normal force, but fluctuates significantly when the critical load of coating delamination is reached. A three-dimensional (3D) finite element (FE) model with a cohesive-zone interface was developed to simulate the scratch process, and by comparing with the delamination critical load from the experiment, the interface characteristic length, the maximum strength and the fracture energy can be obtained. The preliminary results indicate that it is feasible to use the FE simulation combined with scratch tests to evaluate the coating interface behaviors.