The Fluorescence Characteristic of AO-RB-SDS-GMFX and the Determination of Gemifloxacin

In Britton Robinson (B-R) buffer solution with pH = 7.00 and sodium dodecyl sulfate (SDS) medium, an effective energy transfer between acridine orange (AO) and Rhodamine B (RB) can occur, which can enhance the fluorescence of RB. The addition of Gemifloxacin (GMFX) can quench the fluorescence of RB. So a new method for the indirect determination of Gemifloxacin was established by AO-RB fluorescence resonance energy transfer. This method was applied to the determination of Gemifloxacin tablets. The results were consistent with those of high performance liquid chromatography (HPLC) . Experiments show that this method is simple, rapid, accurate and sensitive.

Improvement of ligand-free modification strategy to obtain water-stable up-converting nanoparticles with bright emission and high reaction yield

Water-dispersible up-converting nanoparticles (UCNPs) are known to be very effective in biomedical applications. Research groups have paid special attention to the synthesis of hydrophilic UCNPs with good physicochemical properties. Being aware of this, we decided to improve the ligand-free modification method of OA-capped NaYF4:Yb3+,Er3+/NaYF4 UCNPs prepared by precipitation in high-boiling-point solvents as the thus-far reported methods do not provide satisfactory results. Different molarities of hydrochloric acid and various mixing times were selected to remove the organic ligand from the NPs’ surface and to discover the most promising modification approach. Highly water-stable colloids were obtained with a very high reaction yield of up to 96%. Moreover, the acid treatment did not affect the morphology and the size of the product. All of the crystals exhibited a bright up-conversion emission under 975-nm excitation, which confirmed the two-photon excitation and effective energy transfer between the used dopant ions. Thus, we could establish the most successful ligand-free modification procedure.

Improvement of Ligand-Free Modification Strategy: How to Obtain Water-Stable Up-Converting Nanoparticles With Bright Emission and High Reaction Yield?

Water-dispersible up-converting nanoparticles (UCNPs) are known to be very effective in biomedical applications. Research groups have paid special attention to the synthesis of hydrophilic UCNPs with good physicochemical properties. Being aware of this, we decided to improve the ligand-free modification method of OA-capped NaYF4:Yb3+,Er3+/NaYF4 UCNPs prepared by precipitation in high-boiling-point solvents as the thus-far reported methods do not provide satisfactory results. Different molarities of hydrochloric acid and various mixing times were selected to remove the organic ligand from the NPs’ surface and to discover the most promising modification approach. Highly water-stable colloids were obtained with a very high reaction yield of up to 96%. Moreover, the acid treatment did not affect the morphology and the size of the product. All of the crystals exhibited a bright up-conversion emission under 975-nm excitation, which confirmed the two-photon excitation and effective energy transfer between the used dopant ions. Thus, we could establish the most successful ligand-free modification procedure.

Exploring the Effects of Bay Position Chlorination on the Emissive Properties of Chloro-(Chloro)n-Boron Subnaphthalocyanines for Light Emission.

<p><b>Abstract:</b> It has been previously found that through an established synthesis of the macrocycle boron subnaphthalocyanine (BsubNc) that random bay-position chlorination occurs and results in a mixed alloyed composition that cannot be separated; called chloro-(chloro_n)-boron subnaphthalocyanines (Cl-Cl_nBsubNcs). Through modifications of the synthetic method, amounts of the average bay-position chlorination can be varied. Cl-Cl_nBsubNcs are fluorescent and therefore here we explore the effect of the amount of bay-position chlorination on the photoluminescent and electroluminescent properties of Cl-Cl_nBsubNcs. Distinct from previous reports detailing the positive impact of higher average bay-position chlorination, we find that the photophysical processes important to OLEDs improve with lower average bay-position chlorination. A higher degree of bay-position chlorine shows higher nonradiative recombination rates, lower photoluminescence quantum efficiencies and a basic OLEDs exhibits a greater host emission fraction, implying less effective energy transfer. These results advance the consideration of subnaphthalocyanines for light-emitting and optoelectronic applications.</p>

Exploring the Effects of Bay Position Chlorination on the Emissive Properties of Chloro-(Chloro)n-Boron Subnaphthalocyanines for Light Emission.

<p><b>Abstract:</b> It has been previously found that through an established synthesis of the macrocycle boron subnaphthalocyanine (BsubNc) that random bay-position chlorination occurs and results in a mixed alloyed composition that cannot be separated; called chloro-(chloro_n)-boron subnaphthalocyanines (Cl-Cl_nBsubNcs). Through modifications of the synthetic method, amounts of the average bay-position chlorination can be varied. Cl-Cl_nBsubNcs are fluorescent and therefore here we explore the effect of the amount of bay-position chlorination on the photoluminescent and electroluminescent properties of Cl-Cl_nBsubNcs. Distinct from previous reports detailing the positive impact of higher average bay-position chlorination, we find that the photophysical processes important to OLEDs improve with lower average bay-position chlorination. A higher degree of bay-position chlorine shows higher nonradiative recombination rates, lower photoluminescence quantum efficiencies and a basic OLEDs exhibits a greater host emission fraction, implying less effective energy transfer. These results advance the consideration of subnaphthalocyanines for light-emitting and optoelectronic applications.</p>

Parametric studies on interacting parameters influencing heat pipe performance

The performance of a heat pipe is governed by many parameters, the effects of which may influence each other. Hence, it is utmost important to optimize the combination of these parameters for an effective energy transfer in a heat pipe. In the present study, the interacting effects of four different parameters affecting the effectiveness of heat pipe are studied namely the fluid filling ratio (20%, 30%, 40%), the pressure inside the heat pipe (0.2 bar, 1 bar, 1.8 bar), the number of wick layers (0, 1, 2) and the inclination angle of heat pipe (0°, 45°, 90°). The response surface method based on central composite design approach is applied to optimize the number of experiments. The effects of interacting parameters on the effectiveness of heat pipe are discussed. Among the various parameters, the pressure inside the heat pipe was found to be the most important parameter followed by the fluid filling ratio, the inclination of heat pipe and the number of wick layers. From the analysis, the optimum combination of parameters was obtained as 40% filling ratio, 0.2 bar pressure, 2 wick layers and 0° inclination. At this point, the effectiveness predicted with the model and obtained through experiments was found to be 0.630 and 0.649 respectively. Based on the experimental results, a quadratic empirical model is developed which predicts the effectiveness of heat pipe within [Formula: see text]% of the experimental results for different operating conditions of heat pipe.