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Acetonitrile, a polar molecule that cannot form hydrogen bonds on its own, interacts with solvent molecules mainly through the lone pair of its nitrogen atom and the π electrons of its CN triple bond [Correction added on 17 July 2024, after first online publication: Acetole has been changed to Acetonitrile in the preceeding sentence.]. Interestingly, acetonitrile exhibits an unexpected strengthening of the triple bond's force constant in an aqueous environment, leading to an upshift (blueshift) in the corresponding stretching vibration: this effect contrasts with the usual consequence of hydrogen bonding on the vibrational frequencies of the acceptor groups, that is, frequency redshift. This investigation elucidates this phenomenon using Raman spectroscopy to examine the behavior of acetonitrile in organic solvent, water, and silver ion aqueous solutions, where an even more pronounced upshift is observed. Raman spectroscopy is particularly well suited for analyzing aqueous solutions due to the minimal scattering effect of water molecules across most of the vibrational spectrum. Computational approaches, both static and dynamical, based on Density Functional Theory and hybrid functionals, are employed here to interpret these findings, and accurately reproduce the vibrational frequencies of acetonitrile in different environments. Our calculations also allow an explanation for this unique behavior in terms of electric charge displacements. On the other hand, the study of the interaction of acetonitrile with water molecules and metal ions is relevant for the use of this molecule as a solvent in both chemical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Triboelectrification, a process that transforms mechanical energy into electrical energy through friction, holds promise for eco-friendly wastewater treatment. This study delves into the enhancement of tribocatalytic dye degradation using SrTiO3, a material notable for its non-piezoelectric and centrosymmetric properties. The synthesis of uni- and bi-doped SrTiO3 particles, achieved through a solid-state reaction at 1000 °C, results in a high-purity cubic perovskite structure. Doping with rhodium (Rh) and carbon (C) causes crystal lattice contraction, internal stress, and significant oxygen vacancies. These changes notably improve tribocatalytic efficiency under solar irradiation, with Rh-doped SrTiO3 demonstrating an impressive degradation rate of approximately 88% for Rhodamine B (RhB), along with reaction rate constants near 0.9 h−1 at 554 nm and a noticeable blueshift. This study highlights that defects introduced by doping are integral to this process, boosting catalytic activity through energy state modification and enhancing surface redox radical production. Additionally, these defects are instrumental in generating a flexoelectric field, which markedly influences the separation of electron–hole pairs under solar irradiation. Our findings illuminate the complex interplay between material composition, defect states, and environmental conditions, paving the way for advanced strategies in environmental remediation through optimized tribocatalytic activity.

The distinctive electron structures of luminescent radicals offer considerable potential for a diverse array of applications. Up to now, the luminescent properties of radicals have been modulated through the introduction of electron-donating substituents, predominantly derivatives of carbazole and polyaromatic amines with more and more complicated structures and redshifted luminescent spectra. Herein, four kinds of (N-carbazolyl)bis(2,4,6-tirchlorophenyl)-methyl (CzBTM) radicals, Ph2CzBTM, Mes2CzBTM, Ph2PyIDBTM, and Mes2PyIDBTM, were synthesized and characterized by introducing simple phenyl and 2,4,6-trimethylphenyl groups to CzBTM and PyIDBTM. These radicals exhibit rare blueshifted emission spectra compared to their parent radicals. Furthermore, modifications to CzBTM significantly enhanced the photoluminescence quantum yields (PLQYs), with a highest PLQY of 21% for Mes2CzBTM among CzBTM-type radicals. Additionally, the molecular structures, photophysical properties of molecular orbitals, and stability of the four radicals were systematically investigated. This study provides a novel strategy for tuning the luminescent color of radicals to shorter wavelengths and improving thermostability. [ABSTRACT FROM AUTHOR]

This work used an aqueous-phase method to prepare Sm-doped CdTe nanocrystals (NCs). The successful doping of Sm into the CdTe lattice was confirmed by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), as well as UV–Visible (UV–Vis) absorption and emission spectroscopies. The CdTe and CdTe:Sm NCs are monodispersed as uniform spherical nanocrystals with cubic structures. The particle diameters are ∼4.2, ∼3.3, and ∼2.6 nm for CdTe, CdTe:Sm(5%) and CdTe:Sm(10%) NCs, respectively. Compared with pure CdTe, the CdTe:Sm(5%) NCs exhibit a blueshift of 9–23 nm in their absorption bands and a blueshift of 8–17 nm in their emission bands. With increasing concentration of Sm3+, the quantum yield (QY) of the CdTe:Sm NCs increases initially and then decreases. The CdTe:Sm NCs have longer fluorescence lifetimes than CdTe, probably due to the introduction of trap states. Due to charge compensation, the CdTe:Sm NCs have much stronger emission peaks. [ABSTRACT FROM AUTHOR]

Monolithic multi‐color light‐emitting diodes (LEDs) offer numerous advantages as multi‐functional lighting sources. However, the achievement of full‐color monolithic LEDs spanning from red to blue wavelengths is limited by the InN‐GaN material system. To overcome this limitation, this work demonstrates a new approach using hexagonal epitaxial lateral overgrowth to reduce the density of crystal defects and form micro‐surface structures. By utilizing arrowhead‐like surfaces in semipolar GaN films, indium incorporation can be controlled, leading to larger band‐filling effects and enabling full‐color red, green, and blue emissions from a single LED. Nonetheless, the red emission in monolithic full‐color LEDs is weaker than the blue emission due to the band‐filling induced blueshift that occurs with increasing current injection. To address this issue, pulse amplitude modulation and pulse width modulation modes are introduced to control the emission intensity from red to blue wavelengths. As a result, the study achieves a monolithic trichromatic white LED with color coordinates of (0.2985, 0.3948) and a color temperature of ≈6700 K by simultaneously emitting red, green, and blue LEDs with the same emission intensities. This achievement holds great promise for the development of high‐performance full‐color LEDs for multifunctional lighting sources that can span red, green, and blue wavelengths. [ABSTRACT FROM AUTHOR]

The distinctive electron structures of luminescent radicals offer considerable potential for a diverse array of applications. Up to now, the luminescent properties of radicals have been modulated through the introduction of electron-donating substituents, predominantly derivatives of carbazole and polyaromatic amines with more and more complicated structures and redshifted luminescent spectra. Herein, four kinds of (N-carbazolyl)bis(2,4,6-tirchlorophenyl)-methyl (CzBTM) radicals, Ph2CzBTM, Mes2CzBTM, Ph2PyIDBTM, and Mes2PyIDBTM, were synthesized and characterized by introducing simple phenyl and 2,4,6-trimethylphenyl groups to CzBTM and PyIDBTM. These radicals exhibit rare blueshifted emission spectra compared to their parent radicals. Furthermore, modifications to CzBTM significantly enhanced the photoluminescence quantum yields (PLQYs), with a highest PLQY of 21% for Mes2CzBTM among CzBTM-type radicals. Additionally, the molecular structures, photophysical properties of molecular orbitals, and stability of the four radicals were systematically investigated. This study provides a novel strategy for tuning the luminescent color of radicals to shorter wavelengths and improving thermostability.

The striking change in the emission color/intensity of piezochromic luminescent materials in response to external mechanical stimuli (e.g., pressure, grinding, and stretching) has attracted attention due to potential applications in optical data storage devices, pressure sensors, and optoelectronic devices. The majority of organic materials show redshifted and quenched emission with increasing pressure. Herein, covalently linked donor/acceptor (D/A) o‐carborane dyads that exhibit dual luminescence peaks due to the occurrence of photoinduced electron transfer (PET) are reported. Interestingly, an anomalous phenomenon of pressure‐induced blueshifted and enhanced luminescence is clearly observed. From 1 atm to 1.09 GPa, the restriction of intramolecular motion increases the luminescence of o‐carborane dyads. At high pressures, the compressed o‐carborane unit suppresses PET and decreases the energy gap between the upper excited states. Since the rate of the internal conversion (IC) process is higher than that of PET, the charge transfer (CT) emission gradually disappears, causing the o‐carborane dyads to exhibit blueshifted luminescence. Therefore, a novel strategy for achieving the pressure‐induced enhanced and blueshifted luminescence characteristics of organic materials is reported in this work. [ABSTRACT FROM AUTHOR]

The current availability of multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials with excellent color purity and high device efficiency in the deep‐blue region is appealing. To address this issue in the emerged nitrogen/carbonyl MR‐TADF system, we propose a spiro‐lock strategy. By incorporating spiro functionalization into a concise molecular skeleton, a series of emitters (SFQ, SOQ, SSQ, and SSeQ) can enhance molecular rigidity, blue‐shift the emission peak, narrow the emission band, increase the photoluminescence quantum yield by over 92 %, and suppress intermolecular interactions in the film state. The referent CZQ without spiro structure has a more planar skeleton, and its bluer emission in the solution state redshifts over 40 nm with serious spectrum broadening and a low PLQY in the film state. As a result, SSQ achieves an external quantum efficiency of 25.5 % with a peak at 456 nm and a small full width at half maximum of 31 nm in a simple unsensitized device, significantly outperforming CZQ. This work discloses the importance of spiro‐junction in modulating deep‐blue MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

The structural parameters, photoluminescence (PL), and magnetic characteristics of MxSn1−xOy (M/SnO2) nanocomposites, synthesized by the hydrothermal method, where x = 0.0, 0.5, and M present non-magnetic metals (Cu, Al) and magnetic metals (Fe, Ni, Mn) were studied. The crystallite size and porosity of SnO2 were reduced by mixing with Cu, Al, Fe, or Ni, meanwhile, increased by integrating with Mn. The residual stress of SnO2 was increased 5-fold by Mn doping. The energy dispersive X-ray analysis revealed that Al is the lowest ion for full acceptor incorporation into the SnO2 lattice, while the other doped metal ions show better incorporation. SnO2 doping has a significant impact on the particle morphologies of MxSn1−xOy nanocomposites. The Debye temperature (θD) and Young's modulus (Y) were estimated from the FTIR spectra. The value of θD is 633.86 K for SnO2 nanoparticles and increased to 694.68 K for Mn/SnO2, while it decreased to 608.27 K for Fe/SnO2. The value of Y was increased from 518.30 GPa for SnO2 to 864.41 GPa for Cu/SnO2 nanocomposite. The PL intensity of SnO2 was decreased by Cu, Fe, Ni, and Mn doping, whereas it was increased by Al doping. The blueshift was observed for Al/SnO2 and Mn/SnO2, whereas it is a slight ultraviolet shift for Cu/SnO2, Fe/SnO2, and Ni/SnO2 nanocomposites. SnO2 nanoparticle and Al/SnO2 nanocomposite exhibit weak ferromagnetic behavior by increasing the magnetic field (H) up to 4 kG, while with further increase in H, the samples exhibit diamagnetic behavior. In contrast, the Fe/SnO2, Ni/SnO2, and Mn/SnO2 nanocomposites show a paramagnetic trend, while the Cu/SnO2 nanocomposites exhibit a diamagnetic trend in the magnetic field range of 0–20 kG. The saturated magnetization and magnetic moment are enhanced for all MxSn1−xOy nanocomposites, whereas the corrective field and magnetic anisotropy are decreased compared to SnO2 nanoparticles. The findings recommended SnO2 and Al/SnO2 composites for spintronic devices and cathode–luminescence displays, Fe/SnO2, Ni/SnO2, and Mn/SnO2 nanocomposites for magnetic imaging, and Cu/SnO2 composites for catalytic and plastic deformation applications. [ABSTRACT FROM AUTHOR]

Lead-based perovskite solar cells have experienced tremendous growth and achieved an outstanding power conversion efficiency (PCE) of 27.4% during the last decade. However, lead poisoning has remained a matter of concern for commercialization. Therefore, researchers are looking for alternative perovskite materials free from lead. Cesium-based perovskite material CsGeIXBr3−X may be a promising alternative due to its favorable optical conductivity and light absorption coefficient. To understand the atomic level calculation of perovskite solar cells (PSCs), a detailed model of interaction between the electrons and the interface is strongly anticipated. The optoelectronic property of the perovskite absorber layer has the most significant impact on device performance. Using Density functional theory (DFT), we can precisely predict the behavior of charge transport layers, including the active perovskite layer. In this work, we have done first-principles calculations based on DFT to analyze the electronic and optical properties of lead-free full inorganic CsGeIXBr3−X perovskite compounds. In addition, we incorporate DFT-extracted values of the electronic band gap, the effective density of states, and the optical absorption spectrum in the Solar cell capacitance simulator (SCAPS-1D) program to understand the device performance with the variation of thickness and total defect density of the perovskite layer. We obtained the value of the energy bandgap as 1.363 eV for CsGeI3, 1.5795 eV for CsGeI2Br, 1.7493 eV for CsGeIBr2 and 1.885 eV for CsGeBr3. The CsGeI3-based device performs best and achieves maximum power conversion efficiency (PCE) of 27.63%. It was observed that while increasing the doping concentration of Br in CsGeIXBr3−X perovskites, the bond length decreases, and consequently, the bandgap increases. Also, as the doping concentration increases, a substantial blue shift was observed in the calculated optical conductivity and absorption spectra. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) photocatalyst is an excellent solution that can be utilized to decompose organic pollutants. In this report, Ni-doped TiO2 immobilized on silica gel bead by sol–gel process was investigated. The morphology, crystal phase composition, particle size, porosity characteristics, and optical properties of the samples were investigated through scanning electron microscopy, high-resolution transmission electron microscopy, x-ray diffraction, N2 isothermal loops, Raman spectroscopy, and ultraviolet–visible (UV–Vis) absorption. The results revealed that Ni2+ uniformly distributed in the TiO2 crystal lattice to replace Ti4+ and that Ni2+ did not change the TiO2 anatase crystal phase. Compared with pure TiO2, the absorption edge of the Ni-doped TiO2 sample exhibited a redshift from 400 nm to 655 nm. Influenced by silica gel bead as catalyst support, the crystal size of Ni-doped TiO2 sample was reduced from 27 nm to 6 nm that led to a blueshift in both Raman and UV–Vis spectra. The photocatalytic enhancement was demonstrated by methyl orange decomposition. Under ultraviolet irradiation, the photocatalytic performance of Ni-doped TiO2 immobilized on silica gel bead was lower compared with pure sample. Opposite to this, Ni-doped TiO2 immobilized on silica gel bead showed photocatalytic enhancement under visible light. [ABSTRACT FROM AUTHOR]

We consider the stability of the maximally-extended Reissnerâ€"Nordström (RN) solution in a Minkowski, de Sitter, or anti-de Sitter background. In a broad class of situations, prior work has shown that spherically symmetric perturbations from a massless scalar field cause the inner horizon of an RN black hole to become singular and collapse. Even if this is the case, it may still be possible for an observer to travel through the inner horizon before it fully collapses, thus violating strong cosmic censorship. In this work, we show that the collapse of the inner horizon and the occurrence of a singularity along the inner horizon are sufficient to prevent an observer from accessing the white hole regions and the parallel Universe regions of the maximally extended RN spaceâ€"time. Thus, if an observer passes through the inner horizon, they will inevitably hit the central singularity. Throughout this article, we use natural units where c = G = 4 π ϵ 0 = 1. [ABSTRACT FROM AUTHOR]

Inorganic light‐emitting diodes (LEDs) possess exceptional advantages for achieving wide wavelength emission ranges. However, certain material limitations should be overcome to alleviate the green gap between InGaN and AlInGaP‐based LEDs. In this study, monolithic red, green, and bluish‐green emissions are achieved by exploiting the blueshift phenomenon, caused by the band‐filling and piezoelectric screening effects. Different‐sized LEDs are designed to control the injection current density on the same wafer. The smaller the size of the LED, the shorter the emission wavelength, resulting in multi‐color emission (from red to bluish‐green). As a result, red, green, and white emissions are individually and simultaneously obtained using dichromatic LED systems, comprising three red and one green LED cell. In addition, a wide range of visible light colors are achieved by adjusting the size of the LEDs and the applies injection current. [ABSTRACT FROM AUTHOR]

This paper reports the Al doping content dependence on structure modification and band gap widening of sol-gel synthesised Al-doped ZnO thin films. The precursor, solvent and stabiliser used to prepare ZnO solution were Zinc Acetate Dihydrate, 2-propanol and ethanolamine, respectively. Molarity fractions of 0, 4, 6 and 8% of Al (NO3)2 as dopant source was incorporated into ZnO host system and prepared by individual buffer solutions. The prepared sols were subsequently deposited onto ITO glass substrates, and the resultant thin films were characterised. XRD patterns exhibit the polycrystalline nature of pure and doped ZnO films, with preferred orientations correspond to (1 0 0), (0 0 2) and (1 0 1) planes. Lattice shrinking is indicated by the decrease lattice constant c due to axial compression. Peaks shifting towards higher angle are observed implying a structural modification over doped thin films that affects the optical properties, which agrees with the lattice shrinking. The absorption edge has an obvious blueshift to the shorter wavelength with increased dopant content. The thin films' energy bands were procured by Tauc's linear extrapolation and was found to be broadening from 3.32 eV to 3.34 eV in 6% Al-doped ZnO. There exists a significant correlation between the applied doping level and the extend of variation of structural properties and ultimately, lattice imperfection. Doping of smaller-atom-sized Al into ZnO concedes with the Burstein-Moss principles. 6% Al doping imposes the highest peak shift and ultimately has the highest impact on lattice parameter and energy band. [ABSTRACT FROM AUTHOR]

Modification of ZnO by doping with 3d metal has been intensively reported, and many interesting applications have been proven. This review elaborated the doping effect of the 3d metal atom (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) on the bandgap of ZnO and their application. The review involved more than 190 articles on the 3d metal-doped ZnO, introducing some fundamental theories, including doping types, nanoparticle synthesis methods, nanoparticle morphologies, and lattice size changes. The preparation methods of 3d metal-doped ZnO and the particle morphology effect are elaborated before discussing the correlation between dopant characteristics (type, content, radii) and the bandgap and crystallite size properties. The review ended with the application and photocatalytic degradation for dye in the visible and ultraviolet irradiation.

Synthesis of nanoparticles (NPs) using plant extracts has been suggested as an environmentally friendly alternative to chemical synthesis of semiconductor NPs. In the present study, ZnO NPs were synthesized by a simple and cost-effective method using Coriandrum sativum leaf extract and zinc acetate as precursors. The as-synthesized ZnO NPs were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analysis. The results confirmed the formation of ZnO NPs with a wurtzite structure, spherical shape and average particle size of 24 nm. The photocatalytic degradation of reactive yellow 186 (RY 186) dye was carried out under direct sunlight irradiation and its degradation efficiency and apparent rate constant (K’app) of reaction were calculated to be 93.38%, and 0.0019 min−1, respectively. The optical band gap value of the as-synthesized ZnO NPs was found to be 3.4 eV, which indicates the presence of blueshift. Owing to the presence of blueshift and a wide band gap of synthesized biogenic ZnO NPs, the overall absorption of sunlight irradiation will be enhanced, which leads to higher degradation efficiency of the dye. The current study thus highlights the optical band gap properties of biogenic ZnO NPs and their significance as a heterogeneous catalyst for the purification of polluted water.

Water-soluble Cd0.9−xZn0.1SnxS (0 ≤ x ≤ 0.06) quantum dots were prepared by dual doping of Sn and Zn via chemical co-precipitation technique. XRD results confirmed the cubic structure of CdS crystallites without generating any secondary peaks due to doping. TEM analysis revealed the structural information of the Sn-doped CdS host. The Sn substitution enhanced the particle size lightly. The surface morphological study revealed that the agglomeration of the samples was decreased. From UV–visible optical study, it was observed that the optical transmittance was suppressed owing to Sn substitution. Absorption peaks were blueshifted, and band gap values were widened due to incorporation of Sn. The strong PL emission peaks were received at 400 nm−1 and weak peaks near 490 nm−1. The peaks originated near the UV region were due to sulfur vacancies on the surface. EDX and FTIR studies confirmed the presence of Sn in the prepared samples. Since the possibility of tailoring the band gap toward a high energy gap, these materials composition may be selected for optoelectronic device fabrication. [ABSTRACT FROM AUTHOR]

Red, green, and blue electroluminescence (EL) in semipolar (11‐22) GaN‐based light‐emitting diodes (LEDs) is achieved using SiO2 hexagonal patterns epitaxial lateral overgrowth (HP‐ELO). The size, density, and area of arrowhead‐like surface structure of the semipolar (11‐22) HP‐ELO GaN are significantly affected by increasing the SiO2 hexagonal patterns from 6.0 to 15.0 μm. The full width at half maximum and the blueshift wavelength of EL spectra increases with increasing from 6.0 to 9.0 μm, and then decreases with increasing the hexagonal pattern width to 15.0 μm. These results show a similar tendency to the surface area of arrowhead‐like structure. In addition, micro‐EL images show that indium localization‐induced low energy emission initiates at the front end of arrowhead‐like pattern, and then blueshifted emissions propagate to the side edges as the injection current increases. Therefore, it suggests that HP‐ELO can control the arrowhead‐like surface structure composed of different indium compositions, which can achieve red, green, and blue emissions of a semipolar (11‐22) HP‐ELO GaN‐based LED. [ABSTRACT FROM AUTHOR]

Theorists of the 20th century had failed to recognize an underlying law of physics governing the propagation of light: linearly propagating electromagnetic radiation (and neutrinos) is subject to the Principle of velocity differential propagation. The Principle, which is shown to rest on sound physics, has two manifestations: the second of these, the blueshifting of light (and neutrinos) within the internal portion of a gravity well, is explored. The Principle is applied to an end-state neutron star (a stable gravitationally collapsed body). Examined is its energy layer, the energy generation/amplification that takes place there, and the mechanism by which the energy escapes to the external world. Highlighted is the steady-state perpetual nature of the process; and its applicability in solving two of the most intractable problems in astrophysics. The implications for cosmology are profound and incontrovertible. [ABSTRACT FROM AUTHOR]

Semiconductors have numerous applications in both science and technology. Several methods have been developed to engineer their band gap, which is one of the most important parameters of semiconductors. Here, it is shown that the incorporation of various amino acids into the crystal lattice of copper (I) oxide, akin to the way living organisms incorporate organic macromolecules into minerals during biomineralization, leads to significant shrinkage in the volume of the host unit cell and a strong blueshift in the band gap of up to ≈18%. In examining the potential location of the bio‐organic molecules within the inorganic host's lattice, a very good fit between the proposed model of incorporation and experimental findings is found. The bioinspired phenomenon of band gap widening is thought to be attributable to the void‐induced quantum confinement effect, even though observed in micrometer‐sized crystals. This hypothesis is supported by developing a tight‐binding model that is found to fit well with the experimental data. The outcome of this research could profoundly impact the fields of light‐emitting and spin‐based devices as well as opens up a new bioinspired route to tune the band gap of semiconductors. [ABSTRACT FROM AUTHOR]

In this methodological paper, we consider two problems an astronaut faces under the black hole horizon in the Schwarzschild metric. (1) How to maximize the survival proper time. (2) How to make a visible part of the outer universe as large as possible before hitting the singularity. Our consideration essentially uses the concept of peculiar velocities based on the "river model." Let an astronaut cross the horizon from the outside. We reproduce from the first principles the known result that point (1) requires that an astronaut turn off the engine near the horizon and follow the path with the momentum equal to zero. We also show that point (2) requires maximizing the peculiar velocity of the observer. Both goals (1) and (2) require, in general, different strategies inconsistent with each other that coincide at the horizon only. The concept of peculiar velocities introduced in a direct analogy with cosmology and its application for the problems studied in this paper can be used in advanced general relativity courses. [ABSTRACT FROM AUTHOR]

[Display omitted] • Type I organic quantum wells (OQWs) were fabricated in physical sense. • Blueshifts in the optical absorptions of the OQWs were observed. • Negative differential resistance (NDR) behaviors were obtained. Construction of organic quantum wells (OQWs) has been a challenge due to the difficulty in fabricating high-quality organic films in large area. Here, type I OQWs are successfully fabricated by using two OSCs with different bandgaps, and they exhibit both negative differential resistance (NDR) effect and absorption blueshift. Moreover, the OQW photoswitches show much higher photoresponsivity than the corresponding organic heterojunction ones. All the above results prove the successful construction of OQWs in a physical sense. [ABSTRACT FROM AUTHOR]

CdSe:Sm nanocrystals (NCs) were synthesized by a water phase method, and their structures, shapes and optical properties were further characterized. X-ray diffraction (XRD) analysis suggested that both the CdSe and CdSe:Sm NCs contained (111), (220) and (311) lattice planes in the zinc blende structure overlapped with the (002), (110) and (112) lattice planes in the wurtzite structure, and the diameters were about 4.2, 3.3 and 2.3 nm for CdSe, CdSe:Sm(8%) and CdSe:Sm(10%) NCs, respectively. All of the CdSe:Sm NCs were monodispersed and uniform spherical nanocrystals. The CdSe:Sm(10%) NCs prepared with different reaction times exhibited constant absorption spectra at 430 nm and a fixed emission peak at 581 nm. Compared with those of pure CdSe NCs, the fluorescence emission of CdSe:Sm(10%) NCs blueshifted 20–36 nm, and the absorption peak initially redshifted and then blueshifted with the prolongation of reaction time. In addition, the Sm2+ doping decreased the fluorescence lifetime and increased the quantum yields (QYs) of CdSe NCs. The QYs of CdSe:Sm NCs increased initially and then decreased with the increase in the amount of doped Sm2+. The initial pH and charge compensator concentration also exhibited significantly enhanced fluorescence emission of CdSe:Sm NCs. CdSe and CdSe:Sm NCs were prepared via a water phase method. The structure and optical properties were investigated; the Sm2+ was doped into CdSe NCs successfully. CdSe and CdSe:Sm NCs all exhibit nearly spherical particles, doping Sm2+ increases the particle size, and the QYs are also enhanced. As the reaction time varies to 1, 2, 5, 8 and 10 h, the emission spectra of CdSe NCs present redshift, while the CdSe:Sm NCs have a fixed emission peak, which is the characteristic peak of Sm2+. As compared with pure CdSe NCs, the emission spectra of CdSe:Sm NCs appear blueshift by 20–36 nm. Doping Sm2+ into CdSe NCs can improve the optical properties. [ABSTRACT FROM AUTHOR]

The influence of the Coriolis inertial force generated by the orbital and spin motions of distant objects on the electromagnetic radiation energies during the exchange of photons between such objects has been considered. A red or blue spectral shift occurrence in a passive observation mode that is not associated with the Doppler effect or other known effects has also been shown. The relations found are used to calculate the spectral shifts for several nearby stars from our galaxy, as well as the spectral shifts of several galaxies. The results are close to the values currently observed. [ABSTRACT FROM AUTHOR]

The glycolipid transfer protein, GLTP, can be found in the cytoplasm, and it has a FFAT-like motif (two phenylalanines in an acidic tract) that targets it to the endoplasmic reticulum (ER). We have previously shown that GLTP can bind to a transmembrane ER protein, vesicle-associated membrane protein-associated protein A (VAP-A), which is involved in a wide range of ER functions. We have addressed the mechanisms that might regulate the association between GLTP and the VAP proteins by studying the capacity of GLTP to recognize different N-linked acyl chain species of glucosylceramide. We used surface plasmon resonance and a lipid transfer competition assay to show that GLTP prefers shorter N-linked fully saturated acyl chain glucosylceramides, such as C8, C12, and C16, whereas long C18, C20, and C24-glucosylceramides are all bound more weakly and transported more slowly than their shorter counterparts. Changes in the intrinsic GLTP tryptophan fluorescence blueshifts, also indicate a break-point between C16- and C18-glucosylceramide in the GLTP sensing ability. It has long been postulated that GLTP would be a sensor in the sphingolipid synthesis machinery, but how this mechanistically occurs has not been addressed before. It is unclear what proteins the GLTP VAP association would influence. Here we found that if GLTP has a bound GlcCer the association with VAP-A is weaker. We have also used a formula for identifying putative FFAT-domains, and we identified several potential VAP-interactors within the ceramide and sphingolipid synthesis pathways that could be candidates for regulation by GLTP. [ABSTRACT FROM AUTHOR]