Influence of 27Al+ ion mixing on the adhesion and interfacial chemistry of Ni films on polyimide and polyester

In order to evaluate the influence of ion chemistry on ion-induced interfacial chemistry and thin film adhesion, 30 nm Ni films on polyester (PET) and polyimide (PI) substrates were implanted with various doses (1-10 x 10¹⁶ Al/cm²) of 50 keV ²⁷Al⁺. The ion-induced interfacial chemistry and adhesion were then examined using X-ray photoelectron spectroscopy (XPS) and scratch testing, respectively. The implantation induced extensive interfacial mixing in both types of specimens. In addition, the implanted Al reacted with oxygen in the polymer substrates to form interfacial Al₂O₃ and Al-O-C layers in the Ni/PET and Ni/PI specimens, respectively. Despite the ion-induced interfacial mixing and compound formation, the scratch testing indicated that no significant adhesion enhancement was produced by the ²⁷ Al⁺ ion mixing. The absence of adhesion enhancement was attributed to the absence of complete chemical bonding between the Ni films and the polymer substrates. Criteria for the selection of an effective reactive ion for adhesion enhancement in a given film/substrate system are discussed.     

On The Mechanics of Rubber-to-Metal Bond Failure

In many applications rubber is bonded to metal for fixing purposes or to alter the stiffness. Integrity of the bond is often vital to maintain the required stiffness characteristics and ensure adequate life. The mechanics of bond failure is being studied for various types of deformation. Provided tests are carried out under suitable loading conditions, time-dependent failure with a similar locus has been observed in peeling at 90° or 180°, pure shear and various combinations of simple shear and compression. There are indications that an energetics approach can enable results from different geometries to be quantitatively interrelated. Cavitation-like processes observed in the rubber in the bond region are believed to result from the constraint imposed by the metal and may be the cause of the time-dependent failure.     

“万象更新壶”的造型特征、创新路径及装饰寓意解析

“万象更新壶”以“象”的形态为塑形依据,以“还原法”为创新路径,以“琢砂地”的装饰技法寄托“吉”的情缘,整器造型与装饰浑然一体,营造出宽广的审美空间。     

Complexity measures for assembly language programs

This paper presents the results of a study of the software complexity characteristics of a large real-time signal processing system for which there is a 6-yr maintenance history. The objective of the study was to compare values generated by software metrics to the maintenance history in order to determine which software complexity metrics would be most useful for estimating maintenance effort. The metrics that were analyzed were program size measures, software science measures, and control flow measures. During the course of the study two new software metrics were defined. The new metrics, maximum knot depth and knots per jump ratio, are both extensions of the knot count metric. When comparing the metrics to the maintenance data the control flow measures showed the strongest positive correlation.     

Studies on modeling and control of spouted bed reactors—II: Control

Control and operability characteristics of an adiabatic spouted bed reactor with a first order reaction are investigated. The reactor transient response to changing operating conditions is analyzed and the generic control problems are formulated. Reduced-order state space models suitable for process control studies are constructed by utilizing the methods of orthogonal collocation and singular perturbation.Based on modern control and estimation techniques a hierarchy of different control systems is systematically generated. The assessment of alternative d     

Physico-chemical properties of V-Sb-oxide systems and their catalytic behaviour in oxidative dehydrogenation of light paraffins

Catalysts prepared as bulk VSb_0.1O_x and supported V₂O₅/Al₂O₃, V₂O₅-Sb₂O₃/Al₂O₃ and Sb₂O₃/Al₂O₃ (containing 0.5, 1 or 2 theoretical monolayers of V₂O₅ or Sb₂O₃) were tested in the oxidative dehydrogenation of iso-butane at 550°C in i-C₄H₁₀:O₂:He=20:10:70 gas mixture. Fresh and used catalysts were characterised by BET, XRD and XPS. Reactivity and thermochemistry of active oxygen taking part in the redox cycle with ethane and hydrogene were studied using in situ differential scanning calorimetry. Temperature-programmed desorption of O₂ in He flow was also investigated and in situ DRIFT was applied to investigate surface species of the catalysts in flows of i-C₄H₁₀, O₂ and i-C₄H₁₀/O₂ mixture. Supported VSb_yO_x catalysts are more active and selective than bulk one. V-only supported catalysts display a high efficiency due to the high reactivity of VOX-species. In bulk catalyst, the surface is enriched with antimony. In supported samples, the surfaces V/Sb are close to the calculated ones. In the presence of antimony, the amount of active oxygen species and their reactivity in redox transformation is improved. The rates of vanadium reduction and reoxidation are also higher. Compared to V-only catalysts, supported V-Sb-catalysts display a lower coking activity and higher on-stream stability.     

Improved conversion efficiency of amorphous Si solar cells using a mesoporous ZnO pattern

To provide a front transparent electrode for use in highly efficient hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, porous flat layer and micro-patterns of zinc oxide (ZnO) nanoparticle (NP) layers were prepared through ultraviolet nanoimprint lithography (UV-NIL) and deposited on Al-doped ZnO (AZO) layers. Through this, it was found that a porous micro-pattern of ZnO NPs dispersed in resin can optimize the light-trapping pattern, with the efficiency of solar cells based on patterned or flat mesoporous ZnO layers increased by 27% and 12%, respectively.     

Kinetics of emitted mass—A study with three dry powder inhaler devices

The purpose of this study was to understand the kinetics of emptying of micronised salbutamol sulphate (SS) and lactohale 300 (LH300) under varying air flow rates (30–180 L min⁻¹) from three dry powder inhaler devices, Rotahaler^® (RH), Monodose Inhaler^® (MI) and Handihaler^® (HH). Aerosol concentration vs. time profiles, determined through real-time laser diffraction particle sizing, demonstrated that the majority of the powder from RH was emitted within one second while a more prolonged aerosolisation was observed from MI and HH. Peak aerosol concentrations were achieved more rapidly from RH compared to MI for both SS and LH300. Calculated cumulative emitted mass (CCEM) vs. time profiles were obtained from the aerosol concentration vs. time profiles and the emitted mass and the rate of CCEM (k_CCEM), estimated from a modelling approach, increased with increasing air flow rates. The k_CCEMvs. air flow rate profiles of SS and LH300 were significantly different at high air flow rates. The k_CCEM was highest from RH and lowest from MI. Differences in k_CCEM between the devices were related to capsule aperture size while the differences between the materials were due to the powder bed structure. This approach provided an understanding of the rate at which powder mass emptied from dry powder inhaler devices and was proposed to be a powerful development tool for the future powder inhalers.     

Polymorphisme du dioxotriplomb (II) tetraoxosulfate (VI) Pb3O2(SO4) a basse temperature. II - Etude structurale de la phase ferroelastique gamma-Pb3O2 (SO4) par diffraction neutronique sur poudres a 2 et 45K

Full-profile neutron powder diffraction structure refinements of dioxotrilead(II)tetraoxosulfate(VI) at 2 and 45K reveal that both the alpha- and the gamma-Pb₃O₂ (SO₄) polymorphs have to be refined simultaneously at these temperatures. Accordingly, the paraelastic alpha phase is trapped in the ferroelastic gamma phase, yielding thus mixtures of both compounds in a nearly 1:1 molar ratio. Both structures are essentially similar. The slight variations of the lead-oxygen distances in the infinite edge-sharing tetrahedral (Pb₃ O₂)n double-chains force the sulfate group to adopt nearly C3v and C2v site symmetries respectively in the alpha and gamma phases. The present work is a good example of the behaviour of the DBW3.2 program (1) when mixtures of very similar structures are refined simultaneously (high correlation between some structural parameters).