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排序方式: 共有623条查询结果,搜索用时 15 毫秒
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D. Thirumoolan Vikas A. Katkar G. Gunasekaran Tapan Kanai K. Anver Basha 《Progress in Organic Coatings》2014
Hyperbranched poly(cyanurateamine) (POCYAM) was tested as a novel corrosion inhibitor for mild steel in 0.5–3 M HCl using chemical and electrochemical techniques at 25–70 °C. The results show that this compound has good corrosion inhibiting properties for mild steel in HCl at very low concentrations. Corrosion inhibition efficiency rises with POCYAM concentration. The adsorption of the POCYAM onto the mild steel surface obeys Langmuir adsorption isotherm model. The inhibition mechanism was further corroborated by the values of thermodynamic parameters obtained from the experimental data. 相似文献
33.
A rapid and simple approach for visible determination of mercury ions (Hg2+) in aqueous solutions was developed based on surface plasmon resonance phenomenon using L‐arginine‐functionalized gold nanorods (AuNRs). At pH greater than 9, the deprotonated amine group of L‐arginine on the AuNRs bound with Hg2+ leading to the side‐by‐side assembly of AuNRs, which was verified by transmission electron microscopy images. Thus, when Hg2+ was present in the test solution, a blue shift of the typical longitudinal plasmon band of the AuNRs was observed in the ultra violet‐visible‐near infrared (UV‐Vis‐NIR) spectra, along with a change in the color of the solution, which occurred within 5 min. After carefully optimizing the potential factors affecting the performance, the L‐arginine/AuNRs sensing system was found to be highly sensitive to Hg2+, with the limit of detection of 5 nM (S/N = 3); it is also very selective and free of interference from 10 other metal ions (Ba2+, Ca2+, Cd2+, Co2+, Cs+, Cu2+, K+, Li+, Ni2+, Pb2+). The result suggests that the L‐arginine‐functionalized AuNRs can potentially serve as a rapid, sensitive, and easy‐to‐use colorimetric biosensor useful for determining Hg2+ in food and environmental samples. 相似文献
34.
The properties of concrete using coconut shell as coarse aggregate were investigated in an experimental study. Compressive, flexural, splitting tensile strengths, impact resistance and bond strength were measured and compared with the theoretical values as recommended by the standards. For the selected mix, two different water–cement ratios have been considered to study the effect on the flexural and splitting tensile strengths and impact resistance of coconut shell concrete. The bond properties were determined through pull-out test. Coconut shell concrete can be classified under structural lightweight concrete. The results showed that the experimental bond strength of coconut shell concrete is much higher than the bond strength as estimated by BS 8110 and IS 456:2000 for the mix selected. 相似文献
35.
Inducing and probing non-thermal transitions in semiconductors using femtosecond laser pulses 总被引:1,自引:0,他引:1
Soon after it was discovered that intense laser pulses of nanosecond duration from a ruby laser could anneal the lattice of silicon, it was established that this so-called pulsed laser annealing is a thermal process. Although the radiation energy is transferred to the electrons, the electrons transfer their energy to the lattice on the timescale of the excitation. The electrons and the lattice remain in equilibrium and the laser simply 'heats' the solid to the melting temperature within the duration of the laser pulse. For ultrashort laser pulses in the femtosecond regime, however, thermal processes (which take several picoseconds) and equilibrium thermodynamics cannot account for the experimental data. On excitation with femtosecond laser pulses, the electrons and the lattice are driven far out of equilibrium and disordering of the lattice can occur because the interatomic forces are modified due to the excitation of a large (10% or more) fraction of the valence electrons to the conduction band. This review focuses on the nature of the non-thermal transitions in semiconductors under femtosecond laser excitation. 相似文献
36.
Improving after-the-fact tracing and mapping: supporting software quality predictions 总被引:1,自引:0,他引:1
The software engineering industry undertakes many activities that require generating and using mappings. Companies develop knowledge bases to capture corporate expertise and possibly proprietary information. Software developers build traceability matrices to demonstrate that their designs satisfy the requirements. Proposal managers map customers' statements of work to individual sections of companies' proposals to prove compliance. Systems engineers authoring interface specifications record design rationales as they make relevant decisions. We developed an approach to tracing and mapping that aims to use fully automated information retrieval techniques, and we implemented our approach in a tool called RETRO (requirements tracing on target). 相似文献
37.
Hayes J.H. Dekhtyar A. Sundaram S.K. 《IEEE transactions on pattern analysis and machine intelligence》2006,32(1):4-19
This paper addresses the issues related to improving the overall quality of the dynamic candidate link generation for the requirements tracing process for verification and validation and independent verification and validation analysts. The contribution of the paper is four-fold: we define goals for a tracing tool based on analyst responsibilities in the tracing process, we introduce several new measures for validating that the goals have been satisfied, we implement analyst feedback in the tracing process, and we present a prototype tool that we built, RETRO (REquirements TRacing On-target), to address these goals. We also present the results of a study used to assess RETRO's support of goals and goal elements that can be measured objectively. 相似文献
38.
Generally, inventory control policies for deteriorating items are very sensitive to different marketing policies especially in chemical, food and pharmaceutical industries. Realizing the importance of such inventory policies in practice, an integrated production-inventory-marketing model is developed for determining the economic production quantity (EPQ) and economic order quantity (EOQ) for raw materials in a multi-stage production system. This model considers the effect of different marketing policies such as the price per unit product and the advertisement frequency on the demand of a perishable item. A search method is employed to determine the values of EPQ and EOQ which would result in the maximum total net profit. 相似文献
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