Miracle-dz/UniFAR-FTUs huggingface dataset:
Hydrothermal approach and luminescent properties for the synthesis of orthoniobates GdNbO4:Ln3+ (Ln = Dy, Eu) single crystals under high-temperature high-pressure conditions

Single crystal GdNbO4:Ln3+ (Ln = Dy, Eu) phosphors were prepared via a high-temperature high-pressure hydrothermal procedure at 650 °C under autogenous pressure. X-ray diffraction, field emission scanning electron microscopy, photoluminescence, Raman and XPS were utilized to characterize the as-synthesized phosphors. XRD reveals that the samples begin to crystallize at 550 °C and a pure GdNbO4 phase can be obtained at 650 °C. FE-SEM images indicate that GdNbO4:Ln3+ (Ln = Dy, Eu) samples consist of fine sheets with a size of 50–100 μm. Under UV excitation, the GdNbO4:Eu3+ and GdNbO4:Dy3+ phosphors showed the characteristic emissions of Eu3+ are 5D0 → 7FJ (J = 0, 1, 2, 3, 4), and Dy3+ (4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions), respectively. The preparation method presented here dramatically lowered the traditional temperature of 2300 °C or above in the Czochralski method. The GdNbO4:Dy3+ single crystals showed a bright white emission under different excitation wavelengths with a relatively high quantum yield of 21.7%. The GdNbO4:0.05Eu3+ exhibited excellent bright red luminescence at 612 nm under near-UV excitation, narrowed emission spectra, room temperature luminescence lifetimes of milliseconds and maximum quantum efficiencies of 43.2%.
A facile preparation of palladium nanoparticles supported on magnetite/s-graphene and their catalytic application in Suzuki–Miyaura reaction

Fe3O4 and Pd nanoparticles were assembled on sulfonated graphene (s-G) by an easy chemical approach and characterized by transmission electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. The resulting material could be dispersed homogeneously in water or water/ethanol and further used as an excellent semi-heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction in an environmentally friendly solvent under ligand-free ambient conditions. The high heterogeneous catalytic activity appears to be due to the small size of Pd nanoparticles and homogeneous distribution of the nanoparticles on the Fe3O4/s-G matrix. In addition, the catalytic activity did not deteriorate even after repeated applications, which may be due to the easy and efficient magnetic separation of the catalyst and the high dispersion and stability of the catalyst in an aqueous solution.
Polycationic graft copolymers of poly(N-vinylpyrrolidone) as non-viral vectors for gene transfection

Novel graft copolymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with N-vinylpyrrolidone (NVP) were designed and synthesized by the free radical copolymerization of DMAEMA with precursor polymers of vinyl-functionalized poly(N-vinylpyrrolidone) (PVP). The ability of the PVP- grafted copolymers to bind and condense DNA was confirmed by ethidium bromide displacement assay, agarose gel electrophoresis and transmission electron microscopy. The presence of PVP in the copolymers had a favorable effect on the biophysical properties of polymer/DNA complexes. Colloidal stable complexes obtained from the copolymer systems, were shown to be separate, uniformly spherical nanoparticles by transmission electron microscopy. The approximate diameter of the complexes was 150–200 nm, as determined by dynamic light scattering studies. These results confirm an important role played by the PVP grafts in producing compact stable DNA complexes. The ζ-potential measurements revealed that the incorporation of the PVP grafts reduced the positive surface charge of polymer/DNA complexes. The cytotoxicity of the copolymers decreased with an increasing fraction of PVP. Furthermore, in vitro transfection experiments with these copolymers showed improved ability of transfection in cell culture, demonstrating an important role for PVP grafts in enhancement of the transfection efficiency.
Solubility of Anthracene in Multicomponent Solvent Mixtures Containing Propanol, Butanol, and Alkanes

Experimental solubilities are reported for anthracene dissolved in ternary solvent mixtures 1-propanol + 2-propanol + cyclohexane and 1-butanol + 2-butanol + cyclohexane, for anthracene dissolved in the heptanary solvent mixture 1-propanol + 2-propanol + 1-butanol + 2-butanol + cyclohexane + heptane + 2,2,4-trimethylpentane, and for anthracene dissolved in binary solvent heptane + 2,2,4-trimethylpentane at 298.15 K. For the two ternary solvent systems anthracene mole fraction solubilities are reported at 19 different ternary compositions spanning the entire mole fraction range. In the case of heptanary solvent system, solubility data was measured at eight solvent compositions. Results of these measurements are used to test the predictive ability of the combined nearly ideal multiple solvent (NIMS)/Redlich−Kister and combined NIMS/BAB equations. Computations showed that both solution models provided reasonably accurate predictions for how the mole fraction solubility varied with solvent compositions. Devia.
EFFECT OF THE STRUCTURE OF EXTERNAL ALKOXYSILANE DONORS ON THE POLYMERIZATION OF PROPENE WITH HIGH-ACTIVITY ZIEGLER-NATTA CATALYSTS

Propene was polymerized in bulk in the presence of high activity heterogeneous Ziegler-Natta catalyst with the purpose of finding correlations between the structure of an external alkoxysilane donor and the polymer. Nineteen silane compounds (1–8) of the structure RnSi(OR′)4-n, where n = 1–4, R°C6H5, alkyl or H; R′ = C1–3-alkyl, were used as external donors. The effect of Si/Al mole ratio was studied. The effect of the external alkoxysilane donor on the polymerization strongly depends on the number and size of alkoxy groups and the size of hydrocarbon groups attached to the silicon atom. Two major effects were observed: selective deactivation of atactic active centers and the increased production of high-molecular-weight isotactic polypropylene. Evidently, at least one free non-hindered alkoxy group in the complex between alkoxysilane and AlEt3 is required for the selective deactivation. Also, the size of the hydrocarbon group of the donor strongly influences the selectivity of the deactivation.
Determination of Ascorbic Acid with Wells-Dawson Type Molybdophosphate in Sequential Injection System

Two-electron reduced heteropolyblue is formed very fast at pH 3.75–4.75 in the reaction between Dawson-type molybdophosphate HPA and ascorbic acid (AsA) (ϵ814 = 1.15 × 104 L · mol−1 cm−1). Simple, fast, and direct SIA method for AsA determination was developed. Under found optimal conditions, linear calibration curve was obtained over the range 3 × 10−6–3.5 × 10−4 mol L−1 AsA, and detection limit (3 s) was 1 × 10−6 mol L−1. The proposed SIA method has high sample throughput of 60 h−1 and small reagent consumption. The procedure was applied to the analysis of pharmaceuticals and juices.
Bimetallic Gold/Palladium Catalysts: Correlation between Nanostructure and Synergistic Effects

Au nanoparticles are known to be a good catalyst or an effective promoter for a wide range of catalytic reactions. Bimetallic Au−Pd nanoparticles supported on activated carbon were synthesized following a two-step procedure: immobilization of Au sol onto activated carbon followed by immobilization of Pd(0). The catalysts showed superior activities compared to monometallic Pd or Au nanoparticles on the same support. A series of catalysts with Au:Pd ratios varying from 9.5:0.5 to 2:8 were prepared. These catalysts were characterized by TEM, HRTEM, EDX, and X-ray mapping techniques to obtain morphological information, particle size distributions, crystalline structure, and distribution of the two metals. Correlating with the result from catalytic tests of selective oxidation of glycerol to glyceric acid, we found that the surface configuration of Pd monomers isolated by Au atoms has a substantial effect on activity and stability. The Au:Pd ratio on the surface of the particles is the key parameter and can be.
An Introduction to Clay Colloid Chemistry

particles. In this review, we trace the historical development of under standing clay microstructure by discussing key scientific papers published before 1986 on physico-chemical interactions in fine grained sediments and on clay fabric. Since the development follows an intricate path, the current view of clay microstructure is summarized. This summary includes a discussion of the present state of knowledge, the observations made so far, and the facts that are now established.
Revisiting the construction of graphene–CdS nanocomposites as efficient visible-light-driven photocatalysts for selective organic transformation

The cadmium sulfide (CdS) microsphere decorated graphene (GR) nanocomposite (GR–CdS) was prepared by a facile hydrothermal approach in which CdS ingredients were closely enwrapped by the GR scaffold. The GR–CdS nanocomposite was subjected to a number of characterizations including X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), field emission scanning electron microscopy (FESEM), transmission scanning electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that integration of CdS microspheres with two-dimensional GR scaffolds exerts a profound influence on the properties of hybrid nanocomposites, such as optical and electronic nature along with morphology. Photocatalytic performances of the GR–CdS nanocomposites were evaluated by selective organic transformation under mild conditions. The results demonstrate that the GR–CdS nanocomposite can serve as an efficient visible-light-driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde under ambient conditions. The significantly enhanced photocatalytic performance of GR–CdS nanocomposites can be attributed to the synergistic effect of enhanced light absorption intensity and high electron conductivity of GR, which facilitates charge separation and lengthens the lifetime of photogenerated electron–hole pairs. Moreover, photocatalytic performances of various GR–CdS nanocomposites featuring different degrees of interfacial contact between GR and CdS were also systematically explored. It is anticipated that our work could enrich the information on the preparation of narrow bandgap semiconductor/GR hybrid nanocomposites for a wide range of photocatalytic applications.
Application of Electroactive Films in Corrosion Protection II . Metal Hexacyanometalate Films on Surfaces

This paper reports on the metal hexacyanometalate films, Prussian blue (PB), Ni hexacyanoferrate (NiHCF), and Cu hexacyanoferrate (CuHCF), that were studied for their ability to poise the potential of an oxide-covered metal in a stable, passive region of voltage. This requires the films to catalyze oxygen reduction, and oxygen reduction on PB films was found to be as large as 0.14 mA/cm{sup 2}. However, no net oxygen reduction was observed on NiHCF and CuHCF films. When PB films were galvanically coupled to Ti electrodes, the open-circuit potential was stabilized at 0.38-0.52 V vs. SCE even at area ratios (Ti/PB) as high as 10. PB films directly deposited onto Ti electrodes were also studied. The films could only be reduced at a negative potential ({minus}0.18 V vs. SCE) near the flatband potential for TiO{sub 2}, and electrochemical oxidation did not occur under dark, deaerated conditions. Upon exposure of reduced PB on TiO{sub 2} to dissolved O{sub 2}, or to illumination, the PB film was oxidized and the coupled system adopted a stable potential between +0.2 and 0.3 V.
Synthesis and characterization of conducting poly(o-aminobenzyl alcohol) and its copolymers with aniline

Polyaniline, poly(aniline-co-o-aminobenzyl alcohol), and poly(o-aminobenzyl alcohol) have been synthesized. Conductivities of the HCl-doped polymers ranged from 10 -1 S cm -1 for polyaniline to 10 -3 S cm -1 for poly(o-aminobenzyl alcohol). Copolymer compositions show that both monomers have similar reactivities. The substituted polymers showed enhanced thermal stability and hydrogen-bonding interactions. The results were rationalized based on the effect of the -CH 2 OH substituent on the polymer structure
Radial growth behavior and characteristics of m-plane In0.16Ga0.84N/GaN MQW nanowires by MOCVD

We demonstrate the growth of high-quality non-polar (m-plane) and semi-polar (r-plane) multiple quantum well (MQW) nanowires (NWs) for high internal quantum efficiency optoelectronic device applications. Highly aligned InGaN/GaN MQW layers were grown radially on the {1-100} sidewalls of c-axis n-GaN NWs on Si(111) substrates by pulsed flow metalorganic chemical vapor deposition (MOCVD) technique. The photoluminescence (PL) measurements revealed that the wavelength and intensity of the MQW structure with various pairs (5 to 20) were observed to be very stable and easily controlled with indium concentration. The cathodoluminescence (CL) spectrum of individual InGaN/GaN MQW NWs is dominated by the band-edge emission at 369 and 440 nm with a relatively homogeneous profile of parallel alignment. High-resolution transmission electron microscopy (HR-TEM) studies of radial InGaN/GaN MQW NWs measured along and zone axes revealed that the grown NWs were uniform with six non-polar m-plane facets without any dislocations and stacking faults. This kind of high-quality radial NWs are viable high surface area MQW structures for the enhanced efficiency of light emitting diodes.
Bone Scaffold Biomimetics Based on Gelatin Hydrogel Mineralization

Apatite phase Calcium and Magnesium Phosphate doped nanocomposite scaffold has been synthesized in physiological environment by gelatin hydrogel double diffusion technique. Several analytical methods, such as X-ray diffraction (XRD), infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) were applied to characterize physicochemical properties of the studied samples.The results showed that nanocomposite scaffolds were porous with three-dimensionally interconnected microstructure, pore size ranging from 200 to 300 μm nanocrystalline precipitated minerals were dispersed evenly among gelatin fibers. A mineral containing amorphous calcium phosphate and brushite precipitate was formed within the gelatin matrix at 4°C. After incubation in SBF solution at 37°C for 7 days, the mineral phase was changed to nanocrystalline hydroxyapatite. It should be well-known that precursor phases inside a scaffold implanted into the bone are equal to biomimetic adaptation of precursors to hydroxyapatite that is very similar to the bone and has an attentive level of biocompatibility. Therefore, the result confirms the significance of biomimetic calcium and magnesium phosphate bone tissue scaffolds in developing new biomaterials for bone regeneration.
Volatile Constituents of Micromeria persica Boiss., Hymenocrater platystegius Rech. f. and Scutellaria pinnatifida A. Hamilt. subsp. pinnatifida, Three Labiatae Herbs Growing Wild in Iran

Abstract Water-distilled essential oils from the aerial parts of Micromeria persica Boiss. , leaves and stems of Hymenocrater platystegius Rech. f. , which are endemic to Iran, and the aerial parts of Scutellaria pinnatifida A. Hamilt. subsp. pinnatifida were analyzed by GC and GC/MS. Twenty-four components representing 96.1% of the oil of M. persica were identified of which linalool (15.2%), α-pinene (15.0%) and (E)-nerolidol (13.8%) were found to be the major constituents. Seventeen compounds representing 91.7% of the leaf oil and 10 compounds representing 90.7% of the stem oil of H. platystegius were identified. Both oils were rich in α-pinene (16.7% and 18.6%, respectively) and spathulenol (17.1% and 17.9%, respectively). The other main component of the leaf oil was 1,8-cineole (12.9%), and of the stem oil, cis-calamenene (11.2%). Methyl chavicol (81.9%) was the main component among the 11 constituents characterized in the oil of S. pinnatifida representing 100% of the total components detected.
The Sad And Increasingly Deplorable State Of Internet Security

A t a time when we claim to be more focused on security than ever before, when the media routinely conjures images of forensic experts pursuing cyber-criminals in a dazzling game of network cat-and-mouse, and when we are readying the global IP infrastructure to carry all things voice, video and data, the title of this article no doubt constitutes a disturbing claim. But the sad reality is that overall, Internet security really is in horrible shape, arguably worse than ever before. Internet security is, well, lame, and the situation may get worse before it gets better, if indeed, improving security is even achievable.
High Thermopower and Low Thermal Conductivity in Semiconducting Ternary K−Bi−Se Compounds. Synthesis and Properties of β-K2Bi8Se13 and K2.5Bi8.5Se14 and Their Sb Analogues

β-K2Bi8Se13 (I), K2Sb8Se13 (II), K2.5Bi8. 5Se14 (III), and K2.5Sb8. 5Se14 (IV) were synthesized by a molten flux method. The black needles of compound I were formed at 600 °C and crystallized in the monoclinic P21/m space group (No. 11) with a = 17.492(3) A, b = 4.205(1) A, c = 18.461(4) A, β = 90.49(2)°. The final R/Rw = 6.7/5.7%. Compound II is isostructural to I. Both I and II are isostructural with K2Bi8S13 which is composed of NaCl-, Bi2Te3-, and CdI2-type units connecting to form K+-filled channels. The thin black needles of III and IV obtained at 530 °C crystallize in the same space group P21/m with a = 17.534(4) A, b = 4.206(1) A, c = 21.387(5) A, β = 109.65(2)° and a = 17.265(3) A, b = 4.0801(9) A, c = 21.280(3) A, β = 109.31(1)°, respectively. The final R/Rw = 6.3/8.3% and 5.1/3.6%. Compounds III and IV are isostructural and potassium and bismuth/antimony atoms are disordered over two crystallographic sites. The structure type is very closely related to that of I. Electrical conductivity and therm.
Darstellung und Kristallstruktur von CsAlF4 / Preparation and Crystal Structure of CsAlF4

Abstract Single crystals of CsAlF4 have been prepared from a mixture of CsF and AlF3 and investigated by X-ray methods, CsAlF4 crystallizes hexagonally (isostructurally to the new CsCrF4-type) with a = 9.500, c= 3.713 Å, Z= 3, space group P62m-D3h3, No. 189. AgAlF4 crystallizes orthorhombically (isostructurally to a-RbFeF4) with a = 7.108, b = 7.111, c = 5,568 Å, Z = 4.
/sup 13/C NMR spectra of the uranyl tricarbonate-bicarbonate system

The /sup 13/C NMR identification of the uranyl tricarbonate complex (important in solution mining of U from ore and conventional carbonate leaching) is reported. The NMR spectra show the transition from slow to fast carbonate exchange between uranyl ion and bulk water in an accessible temperature range. The taller NMR peak at 162.31 ppM is frm HCO/sub 3//sup -/ and the smaller peak at 168.86 ppM is from the uranyl tricarbonate complex. (DLC)
Enhancing disease resistance in harvested mango (Mangifera indica L. cv. 'Matisu') fruit by salicylic acid

To learn how salicylic acid (SA) may affect disease resistance in mango, mango fruit (Mangifera indica L. cv. ‘Matisu’) were treated with 1 mmol L−1 SA solution under vacuum infiltration for 2 min at a low pressure (−80 kPa) and for an additional 10 min at air pressure. The fruit were inoculated with anthracnose (Colletotichum gloeosporioides Penz.) spore suspension (1 × 104 CFU mL−1) and incubated at 13 °C, 85–95% RH. Disease incidence and lesion diameter in/on the SA-treated fruit were 37.5% and 20.9% lower than that in/on control fruit on the 4th day of incubation. The study further showed that activities of defensive enzymes in the fruit were significantly enhanced by SA treatment. The activity of phenylalanine ammonia-lyase (PAL) and β-1,3-glucanase in the SA-treated fruit was over 6- or 0.9-fold higher than that in control fruit on the 4th day after the fruit being treated with SA, respectively. Level of hydrogen peroxide (H2O2) or superoxide radicals (O2−) generation rate in SA-treated fruit was 22.3% or 79.4% higher than that in controls on the 8th day after the fruit being treated with SA, respectively. These results suggested that PAL and β-1,3-glucanase, as well as H2O2 or O2−, may be involved in the enhancement of disease resistance in mango fruit. Copyright © 2006 Society of Chemical Industry
NEW GENERATION HALO COLUMN FOR FAST ANALYSES OF ASPIRIN AND ATORVASTATIN IN PHARMACEUTICAL PREPARATION

A super-fast (within 4 min only) HPLC method is described for the analyses of aspirin and atorvastatin simultaneously in single dosage formulation. The mobile phase used was water (pH 2.0, adjusted by o-phosphoric acid)-acetonitrile (50:50, v/v) at 1.0 mL/min flow rate with 210 nm detection. The column used was new generation Halo C18(100 × 46 mm; shell particles; 2.7 µm). The capacity factors of aspirin and atorvastatin were 1.20 and 2.01, while the separation and resolution factors were 1.68 and 5.63, respectively. The values of LOD and LOQ for aspirin were 0.10 and 0.50 µg/mL, while these values for atorvastatin were 0.50 and 2.5 µg/mL, respectively. The linearity was observed in the ranges of 0.1 to 5.0 mg/mL for both drugs. The reported method can be used for the quality control of aspirin and atorvastatin in pharmaceutical preparations with good economy. Additionally, this method can also be used for the analyses of aspirin and atorvastatin drugs in biological and environmental samples.
Photoactivation and Detection of Photoexcited Molecules and Photochemical Products

Aerobic photoactivation of photosensitizing dye molecules can lead to the formation of oxygen radicals, singlet oxygen and other partially reduced oxygen species, collectively called reactive oxygen species (ROS), which are responsible for photodynamic damage and the accompanying cytotoxicity. This review briefly describes basic photophysical phenomena involved in the formation of electronically excited states and photochemical processes that play a key role in the generation of ROS. Physicochemical properties of the excited states of the photosensitizing dye molecules and of ROS, particularly their chemical reactivity with selected substrate molecules, as well as major spectroscopic and analytical methods used for the detection and characterization of reactive intermediates involved in photodynamic phenomena, are critically discussed in this paper.
The effect of geometry on the adhesive behavior of bio-inspired fibrils

Inspired by the special climbing ability of geckos and insects, the effects of geometry, including the end-shape and size, on the adhesion features of bio-inspired fibrils, are investigated. It is found that, the adhesion force of a mushroom-shaped fibril in perfect contact with a rigid substrate decreases with the increase of the peeling angle, but it will increase with an increasing flange thickness at a determined peeling angle. With the same contact length, the mushroom-shaped fibril can achieve much larger adhesion forces than the cylindrical or spatular one due to a larger effective region of the cohesive zone. The effect of the shaft width of the mushroomed-shaped fibril on the adhesion force with and without interfacial defects is also considered, and the results are further compared qualitatively with the experimental ones. A critical contact length for the mushroom-shaped fibril is further found, above which the adhesion force attains a maximum. For a multi-fibril structure, the phenomenon of almost equal load sharing for each fibril is verified numerically, which is consistent with the existing experimental observation. All the results in this paper should be helpful for the understanding of the micro-adhesion mechanism of biological adhesive systems and the design of novel adhesives.