SYNTHESIS, SPECTRAL CHARACTERISTICS OF CDTE/CDS CORE/SHELL QUANTUM DOTS AND CARBAZOLE ABUTMENT CYANINE DYE

Using mercaptoethanol as a stabilizing agent, CdTe/CdS core/shell structure quantum dots (QDs) were prepared by a one-pot synthesis based on a simple solution route. In addition, a novel carbazole abutment cyanine dye (TCQ) was prepared by a series of chemical reaction. The QDs were characterized by Infrared spectrum and X-ray diffraction, and the fluorescence dye TCQ was determined by 1 H NMR and Mass spectrum. The fluorescence spectra were revealed and results indicated that when the excitation wavelengths of QDs and fluorescence dye TCQ were 400nm and 500nm, respectively, the emission wavelengths of QDs and fluorescence dye TCQ were 515nm and 601nm, respectively. This result suggests that QDs and fluorescence dye TCQ may occur to fluorescence resonance energy transfer by change the excitation wavelength of fluorescence dye TCQ. This also suggests that a novel fluorescence probe base on hydroxyl group on QDs and carboxyl group on TCQ was prepared by condensation reaction, and the probe may be offer an efficient method for biological labeling

AceGPT, Localizing Large Language Models in Arabic

This paper explores the imperative need and methodology for developing a localized Large Language Model (LLM) tailored for Arabic, a language with unique cultural characteristics that are not adequately addressed by current mainstream models like ChatGPT. Key concerns additionally arise when considering cultural sensitivity and local values. To this end, the paper outlines a packaged solution, including further pre-training with Arabic texts, supervised fine-tuning (SFT) using native Arabic instructions and GPT-4 responses in Arabic, and reinforcement learning with AI feedback (RLAIF) using a reward model that is sensitive to local culture and values. The objective is to train culturally aware and value-aligned Arabic LLMs that can serve the diverse application-specific needs of Arabic-speaking communities. Extensive evaluations demonstrated that the resulting LLM called `AceGPT' is the SOTA open Arabic LLM in various benchmarks, including instruction-following benchmark (i.e., Arabic Vicuna-80 and Arabic AlpacaEval), knowledge benchmark (i.e., Arabic MMLU and EXAMs), as well as the newly-proposed Arabic cultural \& value alignment benchmark. Notably, AceGPT outperforms ChatGPT in the popular Vicuna-80 benchmark when evaluated with GPT-4, despite the benchmark's limited scale. % Natural Language Understanding (NLU) benchmark (i.e., ALUE) Codes, data, and models are in https://github.com/FreedomIntelligence/AceGPT.Comment: https://github.com/FreedomIntelligence/AceGP

SYNTHESIS AND STOKES SHIFT OF WATER-SOLUBLE CdTe/CDS CORE-SHELL STRUCTRUE QUANTUM DOTS

CdTe/CdS core-shell structure quantum dots (QDs) has been synthesized using a water-based route. The optical absorbance and photoluminescence spectroscopy measurements reveal that the band gaps of the CdTe/CdS core-shell QDs can be tuned by changing core-shell molar ratio. The core-shell molar ratio dependence of UV-vis spectra and the fluorescence spectra of the series of CdTe/CdS QDs samples has been revealed. The results can prove that there is no separated nucleation during the growth of core-shell structure QDs. The Stokes shift decreases with the increasing of the core-shell ratio, which can be ascribed to the strength of the electron-phonon coupling increasing with the core-shell ratio of QDs increasing. (Received January 15, 2010; accepted January 29, 2010) Keywords: CdTe/CdS; core-shell structure; quantum dots; Stokes shift 1．Introduction Colloidal semiconductor nanocrystals QDs have attracted much attention due to their unique advantages, such as narrow photoemission, strong fluorescence, broad photoexcitation, and high resistance to photobleaching.[1-3] The Ⅱ-Ⅵ compounds generally have wider band gap, larger effective mass and larger exciton binding energies as compared with commonmaterials. The QDs can be commonly prepared in organic solvents at high temperature and followed by functional modification. Although highly stable water-soluble QDs can be produced by organometallic reactions, the size of QDs is relatively large, which can result in lowing the FRET efficiencies Although it is a promising alternative route to organometallic reactions by directly synthesizing thiol-capped II-VI semiconductor QDs in water, [5] QDs could difficultly have narrow available size ranges and wide size distribution. [6] Therefore, polymer coats grown shells on the surface of core QDs are feafible strategies to improve the biocompatibility of QDs[4], which can further increase the size of QDs and introducing the other luminescence. Peng et al synthesized CdTe/CdS core/shell QDs in an aqueous phase using thioacetamide as a sulfur source and the quantum yield of as-prepared CdTe/CdS core/shell QDs reaching 58% In this paper, CdTe/CdS core-shell structure QDs has been synthesized using a water-based route. In this expertiment, the optical prosperties of QDs with different core-shell mole ratio were investigated. This study shows one can regulate emission wavelength by changing the core-shell mole ratio. In addition, the variation of the Stokes shift with the increasing of the core-shell mole ratio was further investigated

The Fabrication of Fragrance Microcapsules and Their Sustained and Broken Release Behavior

Their controlled release property is the most important feature of functional microcapsules and carriers. In this work, melamine resin shell fragrance microcapsules were fabricated in a non-ionic system, and their chemical structure, particle size, and morphology were analyzed. The sustained release property of the prepared microcapsules over 2400 h was studied with a weighing calculation method, and based on the fitting results, the release rate trend was consistent with the Peppas model (y = 100 − 2.30t0.3213). Furthermore, the sustained and broken release behavior of the microcapsules in impregnated fabric samples were investigated for the first time by our proposed Solid Phase Microextraction-Gas Chromatography-Mass Spectrometer (SPME-GC-MS) method. The qualitative and quantitative analysis results showed that the middle and base note compositions were outstanding in the sustained release state, and the top note showed more advantages in the broken release state. In addition, it was found that the characteristic peak species and intensities of the sample finished with the microcapsules were more similar to pure essence oil than the sample finished by traditional methods, suggesting that the prepared microcapsules showed an excellent odor recovery and strength

Targeted Thiazole Orange Derivative with Folate: Synthesis, Fluorescence and in Vivo Fluorescence Imaging

A Thiazole Orange conjugated with folate derivative was synthesized in two steps. Firstly, folate was coupled with 1-(3-aminopropyl)-4-methylquinolinium bromide to afford folate-methylquinolinium bromide, which then reacted with benzothiazolium to obtain the title folate-conjugated compound. The compound was evaluated by 1H-NMR MS, TG/DTA and fluorescence spectroscopic methods. The title compound could selectively target folate receptor expressing tumors according to the in vivo fluorescence imaging preliminarily performed on nude mice with breast tumors

Design Mechanism and Property of the Novel Fluorescent Probes for the Identification of Microthrix Parvicella In Situ

In this study, two novel fluorescent probes, probe A and probe B were designed, synthesized and characterized, based on Microthrix parvicella (M. parvicella) preferring to utilize long-chain fatty acid (LCFA), for the labeling of M. parvicella in activated sludge. The molecular structure of probe A and probe B include long-chain alkane and LCFA, respectively. The results indicated that probe A and probe B had a large stokes shift of 118 nm and 120 nm and high quantum yield of 0.1043 and 0.1058, respectively, which were significantly helpful for the fluorescent labeling. As probe A was more stable than probe B in activated sludge, and the fluorescence intensity keep stable during 24 h, probe A was more suitable for labeling M. parvicella in situ. In addition, through the Image Pro Plus 6 (IPP 6) analysis, a quantitative relationship was established between sludge volume index (SVI) and integral optical density (IOD) of the labeled M. parvicella in activated sludge samples. The relationship between IOD and SVI conforms to Logistic curve (R2 = 0.94)