一种人工天青石矿的浮选及夹带行为的统计分析(英文)

研究浮选参数对泡沫浮选脉石回收率的影响,测试了pH=10时起泡剂类型和捕收剂用量对浮选性能的影响。采用方差分析了测试结果。在用油酸钠作捕收剂的情况下,亲水性矿物的浮选主要是由于Ca+2离子对石英的活化产生的疏水性而导致的夹带作用所引起的;夹带和矿泥包裹层对浮选也有一定的影响。在浮选产物中脉石的夹带程度随着矿石颗粒粒度的减小而增加。实验结果表明,通过增大捕收剂用量、缩短浮选时间,可以减小水流夹带作用,提高浮选的选择性。     

Synthesis of novel silica gel immobilized‐calix[4]arene amide ionophores and their anion binding abilities toward phosphate and chromate anions

This article describes the synthesis and characterization of four new calix[4]arene ionophores 5–7 and 9 and corresponding two new silica gel‐immobilized calix[4]arene ionophores containing pyridine 10 and 11 via modification of calix[4]arene monoamide derivatives 5 and 6 with aminopropyl silica gel, respectively. The extraction studies have been performed using liquid–liquid extraction for receptors 5–7 and 9 and solid–liquid batchwise sorption procedures for receptors 10 and 11 . Obtained extraction results showed that the immobilized‐calix[4] arene ionophores 10 and 11 have high extraction ability toward chromate and phosphate anions as compared to their corresponding monomeric precursors 5 and 6 . © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Micelles and ‘reverse micelles’ with a novel water-soluble diblock copolymer

A series of poly[2-(diisopropylamino)ethyl methacrylate]-block-poly[2-(N-morpholino)ethyl methacrylate], [PDPA-b-PMEMA], have been synthesized by using group transfer polymerization. These novel PDPA-b-PMEMA diblock copolymers dissolved molecularly in aqueous solution at low pH (<6.0) due to the protonation of all tertiary amine residues of both blocks and formed PDPA-core micelles at pH 7.5 by PMEMA block forming the micelle coronas. On the other hand, it was also observed that these diblock copolymers formed near-monodisperse ‘reverse micelles’, PMEMA-core micelles, in n-alkanes with or without requiring cosolvent depending on comonomer ratios. Dynamic light scattering studies indicated monodisperse or near-monodisperse micelles in both cases. The intensity-average radii of the PDPA-core and the PMEMA-core micelles were between 10 nm and 17 nm (polydispersity index, μ₂/Γ² < 0.08) and between 10 nm and 13 nm in n-hexane (μ₂/Γ² < 0.09), respectively.     

An overview of model checking practices on verification of PLC software

Programmable logic controllers (PLCs) are heavily used in industrial control systems, because of their high capacity of simultaneous input/output processing capabilities. Characteristically, PLC systems are used in mission critical systems, and PLC software needs to conform real-time constraints in order to work properly. Since PLC programming requires mastering low-level instructions or assembly like languages, an important step in PLC software production is modelling using a formal approach like Petri nets or automata. Afterward, PLC software is produced semiautomatically from the model and refined iteratively. Model checking, on the other hand, is a well-known software verification approach, where typically a set of timed properties are verified by exploring the transition system produced from the software model at hand. Naturally, model checking is applied in a variety of ways to verify the correctness of PLC-based software. In this paper, we provide a broad view about the difficulties that are encountered during the model checking process applied at the verification phase of PLC software production. We classify the approaches from two different perspectives: first, the model checking approach/tool used in the verification process, and second, the software model/source code and its transformation to model checker’s specification language. In a nutshell, we have mainly examined SPIN, SMV, and UPPAAL-based model checking activities and model construction using Instruction Lists (and alike), Function Block Diagrams, and Petri nets/automata-based model construction activities. As a result of our studies, we provide a comparison among the studies in the literature regarding various aspects like their application areas, performance considerations, and model checking processes. Our survey can be used to provide guidance for the scholars and practitioners planning to integrate model checking to PLC-based software verification activities.     

Fractal features of carbon–nickel composite thin films

This work analyses the three‐dimensional (3‐D) surface texture of carbon–nickel (C–Ni) films grown by radio frequency (RF) magnetron co‐sputtering on glass substrates. The C–Ni thin films were deposited under different deposition times, from 50 to 600 s, at room temperature. Atomic force microscopy was employed to characterize the 3‐D surface texture data in connection with the statistical, and fractal analyses. It has been found that up to 180 s the sputtering occurs in more metal content mode and in greater than 180 s it occurs in more non‐metal content mode. This behavior demonstrated a strong link between the structural and morphological properties of C–Ni composite films and facilitates a deeper understanding of structure/property relationships and surface defects in prepared samples. Furthermore, these findings can be applied to research on the mechanisms to prepare and control high‐quality C–Ni films.     

Selective determination of copper and iron in various food samples by the solid phase extraction

The solid phase extraction method developed using N-benzoyl-N-phenylhydroxylamine as a chelating reagent and Amberlite XAD-1180 as an adsorbent was used for the determination of Cu(II) and Fe(III) in various food samples by flame atomic absorption spectrometry. The samples were digested by using nitric acid and hydrogen peroxide. The Cu concentrations ranged from 1.01 to 5.81 μg g⁻¹ in cereals, from 0.40 to 9.67 μg g⁻¹ in vegetable and fruits and from 0.37 to 0.70 μg g⁻¹ in infusions while the Fe concentrations ranged from 7.48 to 34.3 μg g⁻¹ in cereals, from 5.74 to 260 μg g⁻¹ in vegetable and fruits, from 1.63 to 5.12 μg g⁻¹ in infusions and from 0.24 to 1.56 mg L⁻¹ in beverage samples. The Cu and Fe concentrations found were compared with the results obtained from the other food studies in the world.