We report the synthesis of PbF2:Er3+ particles using a hydrothermal method. The structure and upconversion emission properties of the products are investigated by scanning electron microscopy, X-ray diffractometer, Raman spectrophotometer and fluorescence spectrometry. An increase in Er3+ concentration in the crystals changes the PbF2 structure from a mixed phase to a cubic phase and decreases the grain size to nanoscale levels. Enhanced upconversion efficiency is achieved after annealing resulted from the formation of the cubic phase and the increase of grain size. The optimal Er3+ concentration is found to be 4% after annealing, and applied to the back of a bifacial silicon solar cell, maximum external quantum efficiencies of 0.38% and 0.79% are respectively obtained under 0.77 W/cm2 laser excitation (1560 nm) and AM1.5 + laser co-excitation.
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A simple and rapid HPLC method using a photodiode array (PDA) detector for the analysis of 3-hydroxycarboplatin and its related complex has been established for the first time. Separation of 3-hydroxycarboplatin and 3-hydroxy-1,1-cyclobutanedicarboxylic acid (3-HO-cbdca) was carried out on a Phenomenex ODS3 column using an aqueous solution containing 50 mM ammonium acetate and 5 mM sodium 1-octanesulfonate as the mobile phase. The flow rate was 0.8 mL min-1, the column temperature was 40°C, and the detection wavelength was 230 nm for 3-hydroxycarboplatin and 220 nm for 3-HO-cbdca. Different analytical performance parameters such as precision, accuracy, linearity, stability of the solution, specificity, limit of detection (LOD), limit of quantification (LOQ), and system suitability were determined using the Empower 2 software. The calibration curve of standard 3-hydroxycarboplatin showed good linearity (r = 0.9995) within the range 0.5–1.4 mg mL-1. The method was accurate and precise, with an average accuracy of 100.4% (RSD = 1.53%, n = 9), and the results of the system suitability test showed symmetrical peaks, good resolution (Rs), and repeatability. It can be applied to the quality control of 3-hydroxycarboplatin.
There is an urgent and growing need to reduce the environmental footprints of products and manufacturing processes and to support sustainable material consumption. For engineering applications this implies the need to develop low energy/carbon footprint manufacturing processes tha utilise extended life tooling. In machining, nano-structured coatings can be used to extend service life of cutting tools. However, hard coatings pose a challenge to the re-shaping and re-use of tools. This work investigated the use and re-use of cutting tools by developing selective tool coating removal using laser and conventional chemical de-coating technology. The laser de-coated tools were re-coated and their machining performance was compared to that of chemical de-coated and re-coated tools as well as first generation coated and uncoated tools. The paper presents a comparison of the energy footprints associated with the re-use of tooling. It is concluded that high value tooling can exploit material re-use procedures.
The structure of the inclusion complex of tanshinone II-A and _-cyclodextrin formed under microwave irradiation was studied by the UV, IR, and NMR spectroscopy. The association constant of the complex in water is 210 M-1, as determined from the double reciprocal curve by UV spectroscopy. The enhanced water solubility of the complex was found. Thermal studies proved the increased thermal stability of the inclusion complex.
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