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Ce3+ or Yb3+ singly doped LaBO3 and Ce3+-Yb3+ co-doped LaBO3 were prepared by conventional solid state reactions at 1100 °C and their photoluminescence (PL) properties were investigated. The emission spectrum of LaBO3:Ce3+,Yb3+ contains both the Ce3+ ultraviolet (UV) emissions (355 nm and 380 nm) and the Yb3+ near infrared (NIR) emission (975 nm) when excited by the UV light at 270 nm. By using the data of the Ce3+ decay curves and the PL intensities of both Ce3+ and Yb3+, the energy transfer efficiency (η) from Ce3+ to Yb3+, the actual energy transfer efficiency (AE) and the quantum efficiency (Q) of the Yb3+ emission were calculated. In the Ce3+-Yb3+ co-doped LaBO3, Ce3+ can transfer its absorbed energy to Yb3+ efficiently (η can be over 60%), and Yb3+ shows the Q value over 50% when it accepts the energy from Ce3+, which results in the low AE value ∼30%. The energy transfer process from Ce3+ to Yb3+ may be understood by the charge transfer mechanism: Ce3+ + Yb3+ ↔ Ce4+ + Yb2+. Particularly the Ce3+-Yb3+ co-doped LaBO3 phosphor gives the emissions mainly in the UV range and the NIR range with a portion of visible emissions in eye-insensitive range. This unique property may be suitable for applications in anti-counterfeiting techniques and public security affairs.

Powder samples of Ba 3 Si 6 O 12 N 2 and Ba 3 Si 6 O 9 N 4 were synthesized by solid state reaction method at 1300–1400 °C in H 2 /N 2 (6:94) reductive atmosphere. The structural correlations between the two phases were analyzed based on X-ray diffraction data and neutron diffraction data. The results indicate that Ba 3 Si 6 O 12 N 2 can be converted into Ba 3 Si 6 O 9 N 4 when three O 2− are replaced by two N 3− , meanwhile, one trigeminal N(SiO 3 ) 3 group of two in the unit cell is transformed into (SiO 2 N) 3 ring. The luminescent properties of Eu 2+ doped Ba 3 Si 6 O 9 N 4 were investigated. Ba 3 Si 6 O 9 N 4 :Eu 2+ gives wide excitation and emission spectra since the dopant occupy three different Ba sites. The phosphor shows green luminescence color with three emission peaks at 370 nm, 405 nm and 520 nm excited in the range of 210 nm–470 nm. Both luminescence spectra and decay curves indicate that in the Eu 2+ doped Ba 3 Si 6 O 9 N 4 , the energy transfer occurs from the luminescence centers for the shorter wavelength emissions (Eu1 at 370 nm and Eu2 at 405 nm) to the center for the longer wavelength emissions (Eu3 at 520 nm). The Eu 2+ doped sample has potential application in white LEDs.

Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H3BTC) and Ni(NO3)2, Co(NO3)2 and Cu(NO3)2 gave two discrete 32-membered ring-like allomers, [M2(HBTC)2(NH2CONH2)2(H2O)4]·3H2O (M=Ni(1), Co(2)) and one layered [Cu2(BTC)Cl(H2O)4] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N2 absorption. Cu2+ has the highest N2 adsorbance when soaking with 1, and 1 can keep structure stable when Cu2+ below 0.16 mol L−1 and the soaking time within 24d. As Cu2+ beyond 0.16 mol L−1 and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu2+ amounts obtained Ni2+-Cu2+ hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu2+% increases with Cu2+ additions and close to 100% as Cu2+ being 1.6 mmol. It suggests that 3 is a controlled product and Cu2+ can transform discrete compound 1 into 2D compound 3.

Pressure distribution in heavy oil reservoir was numerical simulated by calculating varying-coefficients Darcy’s equation with boundary element method (BEM) in this paper. Permeability coefficients of Darcy’s equation at different parameters were numerical simulated firstly. Then the pressure contours of nine-spot pattern were given. The simulated results show that the particle shape coefficient and kinematic viscosity have major impact on permeability coefficient. In addition, the influence of permeability coefficient on seepage pressure is obvious. Numerical simulated results can provide quantitative theoretical basis for the well deployment and production estimation in the heavy oil exploitation. The reasonable numerical results indicate that the BEM is effective in dealing with heavy oil seepage problems.

A novel red oxyfluoride phosphor K

Ionothermal reactions of 1,4-benzenedicarboxylic acid (H2BDC) and 4,4′-biphenyldicarboxylic (H2BPDC) with Mn(OAc)2 resulted in 12 compounds divided into four kinds of structural models: [RMI]2[Mn3(BDC)3X2] (1–5, type A), [EMI]2[Mn3(BPDC)4] (6, type B), [RMI]2[Mn2(BPDC)3(H2O)3] (7–9, type C) and [RMI]6[Mn9(BPDC)9(HBPDC)2(OAc)4] (10–12, type D). A combination effect of ligands and IL components can be observed in the structural construction, which also is reflected in the properties of thermal stability and fluorescence. The decomposition temperatures of Mn–BDC compounds are higher than those of Mn–BPDC compounds. The decomposition temperatures decrease with the alkyl chain in [RMI]+, due to a +I inductive effect. The maximum emissions of compounds 1–5 and 6–12 located at ca. 410 or 407 nm are assigned to ILCT of H2BDC and H2BPDC ligands, respectively.

Oxonitridoalumosilicates Y4Al2−2xSi2xO9−2xN2x (0.00 ≤ x ≤ 1.00) were prepared and the substitution effect of [Al3+O2−] pairs by [Si4+N3−] pairs in Y4Al2O9–Y4Si2O7N2 solid solutions on the structure and its corresponding influence on the Ce3+ activated luminescence properties are investigated. Y4Al2−2xSi2xO9−2xN2x (0.00 ≤ x ≤ 1.00) shows two solid solution regions, x = 0.00–0.40 for solid solution I, x = 0.50–1.00 for solid solution II from X-ray and neutron diffraction analysis. In the solid solution I, the Ce3+ emission is mainly in the UV range with the maximum wavelength at 350 nm, and the intensity decreases rapidly with the increase of the N content. In the solid solution II, the Ce3+ doped samples show blue-green luminescence with the maximum wavelength at ∼450 nm and the wide excitation bands extend from UV to 450 nm. The phosphors in the solid solution II are promising candidates for white-LED applications.

A novel ternary-alkaline red emitting fluoride phosphor K2NaGaF6:Mn4+ was successfully synthesized through co-precipitation method. The crystal structure, morphology, electronic band structure and luminescence properties of K2NaGaF6:Mn4+ phosphors were investigated in details by using Rietveld refinement of X-ray diffraction data, scanning electron microscopy (SEM), density functional theory (DFT) calculation and different reaction parameters. The K2NaGaF6 host has a cubic unit cell with the space group Fmm and lattice parameters of a = 8.2577 (4) A, Z = 4, Vcell = 563.08 (8) A3. Under blue light excitation, Mn4+ activated K2NaGaF6 exhibits a bright narrow-band red emission. The PL properties of the K2NaGaF6:Mn4+ red phosphors were optimized with different Mn4+ concentrations and aging times. A warm-white LED device was fabricated using a blue LED chip combined with commercial yellow YAG:Ce3+ phosphor and synthesized K2NaGaF6:Mn4+ red phosphor. The color rendering index (CRI, Ra = 81.6) and corresponding color temperature (CCT = 3643 K) easily reached the commercial warm white light LED standards (Ra > 80 and CCT < 4000 K). All these results indicate that K2NaGaF6:Mn4+ phosphor would be a suitable red phosphor candidate for warm-white LED applications.

Well-defined CoxCeO2+x–MoS2 nanotube hybrids were first obtained by a facile solvothermal method. The Ce0.3Co0.7Ox–MoS2 nanohybrids exhibited superior performance for the hydrogen evolution reaction due to synergistic effects between CoxCeO2+x and MoS2, which significantly reduced the charge-transfer impedance and increased the active sites.

Objective To excavate and analyze the acupoint selection rules of acupuncture for PCOS. Methods A literature search was conducted in databases of Chinese Biomedicine Database (CBM), Chinese National Knowledge Infrastructure Database (CNKI), Wanfang Database, Chongqing VIP Chinese Science and Technology Periodical Database (VIP) and PubMed. All clinical trials evaluating the effects of acupuncture in the treatment of polycystic ovary syndrome (PCOS) were included with or without methods of randomization and/or control. Four authors extracted information and two reviewers recorded information on titles, journals, interventions, main acupoints in self-established Excel sheet. Results The top ten acupoints of acupuncture therapy used most frequently were, by turns, Sānyīnjiāo ( SP 6), Guānyuan ( CV 4), Zhōngji ( CV 3), Zľgōng ( EX-CA 1), Qihai ( CV 6), Zusānlľ ( ST 36), Shenshu ( BL 23), Tiānshū ( ST 25), Guīlai ( ST 29), Zhōngwan ( CV 12). Conclusion Our study indicates that modern acupuncture treatment for PCOS is based on selection of specific acupoints according to traditional Chinese acupuncture theory. Points of spleen meridian, stomach meridian and conception vessel are chosen frequently which are most located on the abdomen and the lower limbs. Specific points used most are the front-mu points, the he -sea points, matching points and the back-shu points.

Hydrothermal syntheses of 2-carboxyethyl(phenyl)phosphinic acid (H2CEPPA) with Bi(NO3)3 and Cd(NO3)2 produce two layered complexes [Bi2(μ3-O)(CEPPA)2] n (1) and [Cd(HCEPPA)2] n (2). Compound 1 is comprised of [Bi4(μ3-O)2(POO)4(COO)4] SBUs which grow into a double wave-like 2D layer with–CH2CH2–spacers. Compound 2 crystallizes in the orthorhombic noncentrosymmetric space group Pca21, exhibiting a double lattice-like layer. Through edge-to-face d∙∙∙π stacking, a 3D supramolecular framework is formed based on 2D lattices. Topological analyses indicate that 1 and 2 have sql (or Shubnikov tetragonal plane net) and kgd (or Shubnikov (3.6.3.6) plane net) topological networks respectively. 1 and 2 are isolated as single crystal pure phases, which is confirmed by powder XRD. TGA shows high thermal stabilities with decomposition temperatures of 1 and 2 being 373 and 303°C respectively. The fluorescent spectra exhibit fluorescence quenching in 1 and sharp emission at 292 nm in 2, which is assigned to intraligand emission.

Eight kinds of 1-methyl-3-alkylimidazolium halide [RMI]X (R=ethyl (E), propyl (P), butyl (B) and amyl (A); MI = imidazolium; X= Cl−, I−) ionic liquids (ILs) were used as reaction media and obtained a series of 2D [RMI]2[Co3(BDC)3X2] frameworks through the ionothermal reactions of 1,4-benzenedicarboxylic acid (H2BDC) with Co(NO3)2·6H2O. The 2D [RMI]2[Co3(BDC)3X2] frameworks exhibit a same (3,6) topology network with [RMI]+ cations locating in the interlayer space. [RMI]+ cations play a template role in the structure constructions, whose influence combining with the effect of X− anions pass to the TG behaviors. The decomposition temperatures of the [RMI]2[Co3(BDC)3X2] frameworks decrease with the alkyl chains in [RMI]+ cations, and the compounds containing Cl− show higher thermal stabilities than those with I−. However, compounds 1–8 exhibit two similar broad emissions at ca. 380 and 390 nm, assigned to ILCT. The RMI+ templates and the X− anions do not exert their influence on the fluorescence.

With their unique properties and potentials in several critical applications, highly crosslinked and conductive nanofibrous films (HCC-NFs) have attracted broad attentions recently. However, it is still a great challenge to produce high-performance and uniform HCC-NFs with controllable thickness on a large-scale. Electrospinning could be used to fabricate nanofiber films, but it falls short in creating intimate mechanical and electrical joints between adjacent nanofibers for crosslink. Herein, a new strategy inspired by the fabric shrinking when drying was applied to produce HCC-NFs. Hydrophilically-engineered electrospun polyacrylonitrile (PAN) nanofiber film was dip-coated in a water solution of PEDOT:PSS, and was then dried naturally. By preventing contraction of the film in its lateral plane while allowing its thickness shrinking, the capillary effect during water evaporation resulted in collapse of the large pore volume in the film and the subsequent joint formations between PEDOT:PSS-coated PAN nanofibers, which are further cemented together by the conductive polymer coating. The electrochemical, electrical and mechanical properties of such fabricated HCC-NFs were studied, and they were successfully applied as electrodes to demonstrate high-rate supercapacitors and as a flexible porous material for electromagnetic interference (EMI) shielding. The studies suggest HCC-NFs produced by this facile method have promising prospects in several applications.

Fiber-shaped templates that can be easily loaded with a large amount of hydrophilic and/or lipophilic active materials in a facile process like dip coating, will find many applications including for wearable electronics. Here, macroscale amphiphilic aerogel-like fiber, made from electrospun glycerol-functionalized polyacrylonitrile (PAN) nanofibers (GPN) on a centering metal wire, is reported. With its high porosity, large void space, and both hydrophilic and lipophilic characteristics, this unique GPN aerogel fiber can absorb a large amount of aqueous and oil solutions dispersed with different active materials. In particular, poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PP) represented water-soluble active material is selected to prepare PP-loaded fiber, which is further coated with polyaniline (PANI). The PP@GPN/Ti and PANI@PP@GPN/Ti fibers are studied as electrodes for flexible yarn-shaped solid-sate supercapacitors. A fiber-length-specific capacitance as large as 243 mF cm−1 is measured at 0.1 mA cm−1, one of the best capacitances ever reported for fiber supercapacitors. Colza oil is also tested as a representative oily solvent to investigate the load capacity of GPN aerogel fiber and a mass loading of 124 μl cm−1 is achieved. These results suggest that our unique amphiphilic aerogel fiber could act as a carrier loading a large amount of active masses for many novel applications.

A series of efficient red phosphors, K2SiF6:Mn4+ (KSFM) particles with highly regular, uniform and anisotropic shapes, were successfully prepared by a two-step chemical co-precipitation method at room temperature without using surfactant and template. A morphological map for KSFM particles with five distinctive shapes was depicted by adjusting KF-HF precipitator dropping speed. Moreover, the photoluminescence, decay curves and Raman spectral dependence of the KSFM phosphors with different morphologies were investigated. Luminescence intensity of the KSFM phosphors is highly correlated with the morphology of KSFM particles, which gradually increased as the particle shapes changed from cube to octahedron. Whereas, Raman spectra and flame atomic absorption spectrophotometer results indicated that Mn4+ concentration in a series of KSFM particles decreased gradually. Growth mechanism of particle is discussed base on reticular density and surface energy. White LED devices made of a blue GaN chip merged with yellow phosphor (YAG: Ce3+) and the obtained KSFM red phosphor could produce warm white light. Drive current testing of the fabricated w-LEDs proved the KSFM phosphor in octahedron shape is more stable than that of the KSFM in cubic shape.

We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+. The crystal structure of Sr8Mg7Si9N22 is composed of corner-sharing and edge-sharing [SiN4] tetrahedra and distorted square-pyramid [MgN5] polyhedra. Under 350 nm excitation, Eu2+ doped Sr8Mg7Si9N22 emits narrow-band blue light with maximum intensity at 450 nm and a fwhm of 38 nm.

ObjectivesA significant number of researches have evidenced that occupational lead (Pb) exposure increased risks of cardiovascular disease. However, evidences about the potential effects of Pb on the cardiac conduction system are sparse and inconclusive. Besides, ryanodine receptors (RyRs) induced dysfunction of cardiac excitation contraction coupling which is considered to be one of the mechanisms in cardiovascular diseases. Therefore, we examined the association between occupational Pb exposure and ECG conduction abnormalities, as well as RyRs in Pb-induced ECG abnormalities.MethodsWe investigated 529 Pb smelter workers, and measured blood lead (BPb), zinc protoporphyrin (ZPP), ECG outcomes and RyR expression levels. Based on BPb levels, the workers were divided into three groups: the BPb not elevated group, the BPb elevated group and the Pb poisoning group. Descriptive and multivariable analyses were performed.ResultsCompared with the BPb not elevated group, the Pb poisoning group had a higher incidence of high QRS voltage, and a lower level of RyR1 gene expression (pConclusionsOur study provided evidences that occupational exposure to Pb may be associated with worse ECG outcomes (high QRS voltage), which might be related to decreased levels of RyR1.

A large number of studies have evidenced that developmental neurotoxicity induced by lead (Pb) is related to oxidative injury. Furthermore, recent studies have found that developmental Pb exposure can induce neurodegeneration in old age. Because of the common presence of Pb in the environment, humans are exposed to this metal throughout their lifetime. However, few studies have explored the changes in lifespan profiles of neurotoxicity, as well as oxidative stress following lifetime Pb exposure. In the present study, rats were exposed to lead acetate from their embryonic stage to old age. Dynamic changes in neurodegeneration, oxidative stress, and endoplasmic reticulum (ER) stress in the brains at postnatal week 3 (PNW3, weaning), 41 weeks (PNW41, adulthood) and 70 weeks (PNW70, old age) were investigated. Pb exposure resulted in neurodegeneration with decreased neuronal densities and brain volumes in PNW3 and PNW70 rats; however, no significant changes occurred in PNW41 rats based on thionine stain analysis and magnetic resonance imaging (MRI) scans. Expression of the ER stress protein glucose-regulated protein 78 (GRP78) increased in Pb-exposed rats, which was associated with high levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in rat brains after Pb exposure in PNW3 and PNW70 rats. Our findings suggested that lifetime Pb exposure induced neurodegenerative injuries that began to occur in infancy, were relieved in adulthood, but intensified in old age. The critical periods for prevention or intervention in neurodegenerative diseases induced by Pb exposure occurred in early life.

We present a strategy for selecting an optimal material in a particular temperature range by investigating the relationship between the absolute sensitivity ( S

Thermosensitive fluorescent [Eu(NDC)(H2O)Cl] (1) (H2NDC = 2,6-Naphthalene dicarboxylic acid) was fabricated with polyether sulfone (PES) into composite films. 40% 1@PES film showed highly sensitive and repeatable thermal sensor properties in an alarm device.

Achieving tunable color and white light emission in a single phase phosphor is a challenging issue. Here, a series of Ce3+-Eu2+ co-doped Ca2Si5N8 phosphors were successfully synthesized by a high temperature solid state method. Luminescence properties, energy transfer (ET) and thermal quenching of the as-synthesized samples were investigated in detail. The emission color of as-prepared Ca1.94Na0.03Si5N8:0.03Ce3+,yEu2+ (0.0000 ≤ y ≤ 0.0035) could be tuned from blue to white light and eventually to orange via ET by changing the Ce3+/Eu2+ ratio. ET efficiency from Ce3+ to Eu2+ could reach up to 68.0% and the ET mechanism was demonstrated to be a non-radiative dipole-dipole interaction. More importantly, when y = 0.0012, approximate standard white light was generated with CIE coordinates of (0.335, 0.341). A photoluminescence (PL) mechanism was proposed to understand PL properties and thermal properties of the as-prepared phosphors. Additionally, the achieved white light phosphor Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ had good thermal stability, exhibiting about 75% at 150 °C and 64% at 200 °C of the emission intensity at 25 °C, respectively. The chromaticity shifts of Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ were 0.0032 at 150 °C and 0.0152 at 200 °C, respectively, which were only 27% and 42% of the commercial white-emitting phosphor mixture at the corresponding temperature. Furthermore, a proof-of-concept white LED was fabricated by combining the single component phosphor Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ with a near UV LED chip. All results demonstrate the promising application of the Ca2Si5N8:Ce3+,Eu2+ single phosphor for near-UV white LEDs.

Introduction A large number of studies have shown that the developmental neurotoxicity induced by lead is related to oxidative injury, meanwhile, oxidative stress is among the most common mechanisms of neurodegeneration. However, few studies have explored the role of oxidative stress in age-related cognitive impairment caused by prolonged lead exposure and oxidative stress. Methods In the present study, rats were exposed to low-level lead from the embryonic stage to old age. Dynamic changes in neurodegeneration, endoplasmic reticulum (ER) stress, and oxidative stress in brains during postnatal weeks 3, 41 and 70 (PNW3, PNW41 and PNW70, respectively) were investigated. Results Lead exposure resulted in neurodegeneration in PNW70 rats based on magnetic resonance imaging (MRI) scans and thionine stain analysis. Amyloid precursor protein (APP) and tau mRNA expression in PNW41 and PNW70 brains increased in a time- and dose-dependent manner. APP and Tau protein levels significantly increased with lead exposure at PNW3 and PNW70. Mechanistically, the expression of the ER stress protein glucose-regulated protein 78 (GRP78) was higher in the presence of lead than in normal controls, which was associated with high levels of 8-hydroxy-2’-deoxyguanosine (8-OHdG) in brain tissues after lead exposure in PNW3 and PNW70, their changes were like as APP and tau protein that were a u- or j-shaped curve with time of lead exposure. Conclusion Our findings suggest that the neurodegenerative injuries induced by lead exposure may be mediated by ER and oxidative stresses, and there is a critical period for prevention or intervention AD in early life and later life, however middle-aged people at the latent stage of neurodegenerative process should not be ignored.

Seven Eu-(H)BDC compounds, [RMI][Eu2(BDC)3Cl] (R = ethyl (1), propyl (2), butyl (3), H2BDC = 1,4-benzenedicarboxylic acid), [EMI]2[Eu2(BDC)3(H2BDC)Cl2] (4), [Eu(BDC)(HCOO)] (5), [Eu(BDC)Cl(H2O)] (6) and [Eu3(BDC)4Cl(H2O)6] (7), were synthesized under ionothermal conditions. Compounds 4 and 6 behave as potential highly selective turn-off fluorescent sensors for aniline, which can be detected in mixtures of aniline with contrast organic amides or alkylbenzenes. Fluorescence quenching can be observed when compounds 4 and 6 mix with the samples containing aniline. Compounds 4 and 6 show basically unchanged emission intensities and rapid response to aniline after ten recycling tests, suggesting that the compounds have high stable recycle repeatabilities.

Tetragonal Yb3+/Er3+/Tm3+ tri-doped AgGd(W,Mo)2O8 phosphors were prepared by the high-temperature solid-state method. When the phosphors were excited at 980 nm, the UC emission of blue at 475 nm, green at 525 and 550 nm, and red at 656 nm were corresponding to the 1G4 → 3H6 transition of Tm3+ ions, the 2H11/2,4S3/2 → 4I15/2 transitions of Er3+ ions, and the 4F9/2 → 4I15/2 transition of Er3+ ions, respectively. The blue UC emissions originate from a three-photon mechanism, while the green and red ones of Er3+ from two-photon process. The UC emission color of the Yb3+/Er3+/Tm3+ tri-doped AgGdW2O8 samples switched from green to white, and then to red depending on the concentrations of Er3+ and Tm3+. After doping with Mo(VI), tetragonal AgGdW2O8 was transformed into tetragonal AgGdMo2O8, resulting in a slightly enhanced UC luminescence intensity with the favor of the red emission of Er3+ ion.

The research on the impacts of modified TiO2 nanoparticles (NPs) on interfacial tension (IFT) is in its infancy. Our work focuses on the IFT of the modified TiO2 and Gemini surfactant N,N,N′,N′-tetramethyl-N,N′-dimyristyl-1,2-ethane diammonium dichlone (YND1233) complex solutions for reservoir stimulation purposes. The factors of YND1233, modified TiO2 NPs, temperature, aging stability, adsorption loss, and mineralized degree were explored with the comparison of unmodified TiO2 NPs and YND1233 as contrast samples. The results indicate that the dynamic IFTs decrease and then increase with the concentrations of YND1233 and modified TiO2 NPs, and the minimum IFT appears at 0.200 and 0.010 wt%, respectively. YND1233/modified TiO2 complex solutions show lower and more stable IFTs, better temperature resistance, longer aging time, and lower adsorption on the surface of quartz sand. The modified TiO2 NPs and YND1233 in the YND1233/modified TiO2 complex solution can be adsorbed to the interface and decrease the I...

A new 3D Cd-triazolate MOF compound [Cd(Hatrz) (SO4)] (1) (Hatrz = 3-amino-1H-1,2,4-triazole) was obtained from in situ decarboxylication of 5-amino-3-carboxyl-1,2,4-triazole (H2atrc) under the hydrothermal reaction of CdSO4 with H2atrc. Compound 1 features itself a Hatrz-supporting 3D architecture based on the connection of inorganic [CdSO4] layers with Hatrz spacers. Cd(II) atom, SO 4 2 − and Hatrz dummied as 6-, 4- and 2-connected nodes respectively, compound 1 can be simplified to a (2,4,6)-connected {44.62.88.12}{44.62}{8} topological network. The thermal stability of 1 is up to ca. 402 °C, and the fluorescence of 1 shows an emission at 366 nm, originating from SO 4 2 − → Cd transfer. PXRD of compound 1 confirms the phase purity of the bulk sample. FT-IR spectrum of 1 is in accord with the structure analysis.

Porous micro- and nanostructured materials with the desired morphologies are of great interest because of their potential applications in environmental remediation. In this study, novel yolk–shell Au@CeO2 microspheres were prepared from glucose and metal salt precursors via a one-pot hydrothermal synthesis followed by precipitation and calcination. These core/shell structure were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, Fourier transform Infrared Spectrometer, X-ray photoelectron spectroscopy and N2 adsorption–desorption techniques. These rattle-type spheres were found to compose of a porous CeO2 shell (thickness ≈ 45 nm) and a solid gold core (diameter ≈ 50 ± 20 nm) with variable space between the core and the shell. The photocatalytic degradation of methylene blue dye was used as a catalytic test reaction revealing that the activity of the yolk–shell spherical products was substantially higher than that of their hollow counterparts. These new core/shell structures with encapsulated gold nanoparticles may exhibit potential applications in catalysis and adsorption.

This study explored optimal preparation conditions for K2GeF6:Mn4+ red phosphors by using chemical coprecipitation method. The prepared hexagonal P3m1 K2GeF6:Mn4+ exhibited efficient red emission, high color purity, good Mn4+ concentration stability, and low thermal quenching. Structural evolution from hexagonal P3m1 to P63mc and then P63mc to cubic Fm3m occurred after thermal treatment at approximately 400 and 500 °C, respectively. Hexagonal P63mc phase showed an obvious zero phonon line peak at 621 nm, whereas cubic Fm3m phase showed no red emission. Yellowish K2GeF6:Mn4+ with both hexagonal P3m1 and P63mc symmetries are promising commercial red phosphors for white light-emitting diodes.

A series of CaMoO4:Eu3 + with diverse morphologies were prepared via co-precipitation method with different organic additives, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The results show that the organic additives do not change the crystal structures of CaMoO4:Eu3 + phosphors, but greatly influence the morphologies and PL intensities of CaMoO4:Eu3 + phosphors. The morphologies of CaMoO4:Eu3 + phosphors were tuned through the fundamental experimental conditions such as the surfactants and binary mixed solvents. The CaMoO4:Eu3 + particles appear as diverse morphologies of leaf- and flower-like microspheres, single and twinned hemispheres, etc., with diameters ranging from 50 nm to 8.0 μm. In our work, six types of surfactants, and two kinds of binary solvent system of EG/H2O and DMF/H2O were investigated on their effect on the morphologies, particle sizes and PL properties of the samples. The red emission of CaMoO4:Eu3 + phosphors locate at 614 nm excited at 395 nm, assigned to Eu3 + characteristic emission.

Uniform yolk–shell Au@Y2O3:Eu3+ sub-microsphere phosphors were successfully prepared through urea-assisted homogeneous precipitation method by using carbon spheres as templates. The structure, morphology, photoluminescence and photocatalytic properties of the as-prepared Au@Y2O3:Eu3+ microspheres were subsequently investigated. The results indicate that the Y2O3:Eu3+ microspheres can be well indexed to the cubic Y2O3 phase. Furthermore, the Au@Y2O3:Eu3+ microsphere is able to maintain the spherical morphology and good dispersion of the carbon sphere template. The yolk–shell Au@Y2O3:Eu3+ spheres exhibit the bright luminescence of Eu3+. The photocatalysis of the Y2O3:Eu3+ shell and the Au core occur simultaneously, thereby significantly decreasing the absorbance of rhodamine B solutions. This work provides a strategy for inhibiting aggregation of noble metal nanoparticles during high-temperature calcinations and leaching of noble metal nanoparticles into a solution through a mesoporous shell. Ultimately, a multifunctional nanostructure was obtained by combining a specific metal core with an oxide shell.

A new class of Mn4+ activated alkali-metal hexafluoride red phosphors are emerging for white light-emitting diodes because of their sharp red line 2Eg → 4A2g emissions (600–650 nm) excited by irradiation of 4A2g → 4T1g (320–380 nm) and 4A2g → 4T2g (380–500 nm) transitions. However, these phosphors have the drawbacks of difficult control of the Mn valence state during synthesis and lack of underlying mechanisms for structure–photoluminescence relationships. In this study, we explore a novel, highly productive route to the quantifiable synthesis of K2GeF6:Mn4+ by the chemical co-precipitation method at room temperature. The prepared yellowish K2GeF6:Mn4+ powders exhibit a hexagonal shape and high crystallinity without significant defects. The photoluminescence thermal stability and white light-emitting diodes applicability of K2GeF6:Mn4+ suggest that it is a promising commercial red phosphor because of its efficient emission intensity, high color purity and excellent thermal stability. Structural analyses and theoretical calculations reveal that the red shift of the K2GeF6:Mn4+ red phosphor compared with K2SiF6:Mn4+ is due to the longer Ge–F distance and lower effective Mulliken charge of F ions in coordination environments of the MnF62− octahedron. The split feature in K2GeF6:Mn4+ is due to the hexagonal distortion in the host. The structure–photoluminescence mechanism is predicted to be general in hexafluoride red phosphors to tune the optical properties through cationic substitutions and crystal structure adjustments.

Two types of 2D [RMI]2[Zn3(BDC)3X2] (Type A) and 3D [Zn(BDC)(H2O)] (Type B) (H2BDC = 1,4-benzenedicarboxylate acid) compounds were synthesized with three kinds of 1-alkyl-3-methyl imidazolium halide ([RMI]X) ionic liquids. Type A is the primary structure model showing a (3,6) network. Type B can be obtained from [BMI]Cl, [AMI]Cl and [AMI]Br media, showing a 4,4-connected {4(2)·8(4)} network. The structure, TG, and fluorescence analyses demonstrate the combination effect of the RMI(+) templating effect and X(-) controlling the structure types. The boundary between Types A and B is from [PMI]Cl, via [BMI]Br, to [AMI]I as the reaction media. The decomposition temperatures of the compounds in Type A decrease with increased RMI(+), while X(-) anions exert the influence that compounds containing Br(-) supply the highest thermal stability. Similarly, with increased RMI(+), or X = I(-), the compounds show red shifts compared to the emissions of the ligand.

Hydrogen peroxide (H2O2) plays an important role in physiological processes. In this work, a Cu-based metal-organic framework (Cu-MOF) was synthesized under ionothermal condition, further grafted with ammoniated Au nanoparticles (AuNPs-NH2) to prepare AuNPs-NH2/Cu-MOF composite. Glassy carbon electrode (GCE) was modified with AuNPs-NH2/Cu-MOF to prepare AuNPs-NH2/Cu-MOF/GCE electrode, which was used in H2O2 detection. AuNPs-NH2/Cu-MOF/GCE exhibits itself as a highly sensitive and selective electrochemical enzyme-free sensor for H2O2 detection. A quantitative detection to H2O2 can be found with a wide linear response toward H2O2 concentrations ranging 5–850 μM, its limit of detection (LOD) is as low as 1.2 μM with a high sensitivity of 1.71 μA/cm2·μM. AuNPs-NH2/Cu-MOF/GCE sensor has been applied to determine H2O2 effectively in human cervical cancer cells by adding the ascorbic acid as the stimulant. Our work presented a AuNPs-NH2/Cu-MOF/GCE composite electrode which is a promising enzyme-free electrochemical sensor for quantitive H2O2 detection in human cervical cancer cells.

Monoclinic Yb 3+ /Tm 3+ /Ho 3+ tri-doped AgGd(WO 4 ) 2 phosphors were prepared by the high temperature solid-state method. White emission via up-conversion process consisting of the blue UC radiations at 475 nm corresponding to the 1 G 4 → 3 H 6 transitions of Tm 3+ ion, green at 542 nm to the 5 F 4 , 5 S 2 → 5 I 8 transition of Ho 3+ ions and red at 650 nm including both the 5 F 5 → 5 I 8 transition of the Ho 3+ ion and the 1 G 4 → 3 F 4 transition of Tm 3+ ion, was observed in the as-prepared powders under the excitation of a 980 nm diode laser. On the basis of spectral and pump power dependence analyses, the blue emission originated from the three-photon process and the green and red emissions originated from the two-photon process, the UC mechanisms for the fine-tuned white output were discussed in detail. Bright white luminescence upon 980 nm near-infrared excitation can be observed for the sample at the optimum chemical composition of AgGd 0.737 Yb 0.200 Ho 0.013 Tm 0.05 (WO 4 ) 2 , which is produced via an up-conversion (UC) process by tuning the dopant ions Tm 3+ concentration. By doping of Mo 6+ , the structure and UC properties of the Yb 3+ /Tm 3+ /Ho 3+ tri-doped monoclinic AgGdW 2 O 8 transformed to a tetragonal one, and the color of UC emission were also tuned with the increase of Mo 6+ concentration. Bright white luminescence upon 980 nm near-infrared excitation can be observed for the sample at the optimum chemical composition of AgGd 0.737 Yb 0.200 Ho 0.013 Tm 0.05 (W 0.6 Mo 0.4 O 4 ) 2 , which is about 9.5 times to that of the AgGd 0.737 Yb 0.200 Ho 0.013 Tm 0.050 (WO 4 ) 2 .

Ca0.28Ba0.72Nb2O6 (CBN28) ceramics with addition of CeO2 and La2O3, were prepared by the conventional ceramic fabrication technique. XRD results showed that the single tungsten bronze structure of CBN28 was not changed by adding CeO2 or La2O3. SEM results indicated that both CeO2 and La2O3 dopants were effective in inhibiting the grain growth and suppressing the anisotropic growth behavior in tungsten bronze structure. It was also found that both two kinds of dopants had remarkable effects on the dielectric and ferroelectric properties of CBN28 ceramics. Compared with CBN28 ceramics, the dielectric constant around room temperature er, dielectric loss tan δ, the degree of diffuseness γ and coercive field Ec were all ameliorated when doping proper amount of CeO2 or La2O3. The comprehensive electric performance was obtained in CBN28–0.3 wt% CeO2 and CBN28–0.4 wt% La2O3 ceramics. Besides, the underlying mechanism for variations of the electrical properties due to different dopants was explained in this work.

Hyperfine red phosphors composed of Eu3 + ion-doped CaMoO4 with varying morphologies were prepared via a facile precipitation method at room temperature without any organic additives. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy were used to characterize the synthesized products. The morphologies of the prepared CaMoO4:Eu3 + phosphors were controllable by adjusting the fundamental experimental conditions such as the pH value of the initial solution, the molar ratios of Ca(NO3)2/(NH4)6Mo7O24, the concentrations of the reactants, the precipitation reagents, and the raw materials. The formation process of CaMoO4:Eu3 + based on the aging time is discussed in detail. The room-temperature photoluminescence properties of the as-prepared CaMoO4:Eu3+ phosphors under diverse experimental conditions were also studied systematically, and their emission spectra showed emission characteristic of Eu3 +.

Wire-shaped solid-state supercapacitors (WSSCs) receive ever-growing interest for developing electronic textile. How to achieve a high active mass loading with a suitable mesoporous structure and strong adhesion on a bare metal wire are a severe challenge faced by the development of practical WSSCs, which must meet requirements such as high energy and power densities, fast rate capability, as well as flexibility and stability. Here, a new strategy to synthesize the wire-shaped electrode with excellent electrochemical and mechanical performances is reported using a soft aerogel template in a facile dip coating process. Hydrophilically engineered polyacrylonitrile nanofibers by adding glycerol were electrospun on a Ti metal wire to form the sacrificial aerogel template with a huge void volume, in which poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution was dip coated to achieve a large mass loading. The capillary effect in the subsequent natural drying process, slow dissolution of the template in a solvent, and PSS etching, together lead to a mesoporous PEDOT thick coating network formed on the metal wire with a high conductivity, strong mechanical strength and intimate interface adhesion. The resulted WSSCs based on Ti/PEDOT electrodes, exhibited a fairly wide potential window, large specific capacitance, ultrahigh rate capability and energy/power densities.

Ca0.28Ba0.72Nb2O6 (CBN28) ceramics with different content of CuO were prepared by the conventional ceramic fabrication technique. The effects of CuO content on the phase structure, microstructure, dielectric and ferroelectric properties of obtained CBN28 ceramics were investigated. XRD results showed that pure tungsten bronze structure was obtained in all ceramics and CuO additive could accelerate the phase formation at lower temperatures. The CuO aid was effective for the uniform grain size in CBN28 ceramics, as it could facilitate the sintering behavior and suppress the anisotropic growth behavior obviously. The dielectric and ferroelectric properties of CBN28 ceramics depended greatly on the CuO content. Curie temperature T c and dielectric loss tanδ both shifted downward, whereas the maximum dielectric constant e m and the dielectric constant around room temperature e r all increased initially and then decreased as x increased from 0.1 to 0.4 wt%. Normal ferroelectric hysteresis loops could be observed in all compositions, and the remnant polarization P r decreased gradually. It was found that the comprehensive electric performance was optimized in CBN28-0.2 wt% CuO ceramics: e r = 453, e m = 3,371, T c = 226 °C, tanδ = 0.048, P r = 4.72 μC/cm2 and E c = 13.81 kV/cm, showed that CuO sintering aid could not only ameliorate the sintering behavior but also improve the electrical properties.

In the binary system (1−x)Li2SO4–xNa2SO4, the solid–solid phase transitions and energy storage properties of Li2SO4, Na2SO4, the binary compound LiNaSO4 and two eutectoids (E1: 0.726Li2SO4–0.274Na2SO4; E2: 0.03Li2SO4–0.97Na2SO4) were investigated by X-ray diffraction and differential scanning calorimetry. Li2SO4 has a solid–solid phase transition at 578 °C with the transition enthalpy 252 J g−1. The binary compound LiNaSO4 gives a slightly lower enthalpy value, 214 J g−1 and its transition temperature is clearly reduced to 514 °C. The transition enthalpy of the eutectoid E1 is maintained to 177 J g−1 and its transition temperature is further reduced to 474 °C. Li2SO4, LiNaSO4 and the eutectoid E1 are applicable phase transition materials because of their large transition enthalpies. The enthalpies of Na2SO4 and the eutectoid E2 are not very high (∼45 J g−1), but their transition temperatures are quite low (∼250 °C); thus their transition properties may be applied at such low temperatures.

To investigate the influence of ionic liquids on the structures and properties of the complexes, ionothermal synthesis of 1,4-benzenedicarboxylate acid (H2BDC) reacting with Co(NO3)2 with four different 1-alkyl-3-methylimidazolium bromides produced three layered metal–organic frameworks with the chemical formula [RMI]2[Co3(BDC)3Br2], (R = ethyl for 1; n-propyl for 2, and n-butyl for 3; MI = imidazolium) and a 3D architecture [AMI]2[Co3(BDC)4] (4) (A = amyl). Compounds 1–3 have the same (3,6) skeleton with [RMI]+ cations located in the interlayer space. Compound 4 grows into a 3D architecture based on BDC2− ligands linking similar 2D grids as those in 1–3. The [RMI]+ templates exert their influence on the diagonal sizes of the quadrilateral grids, the interlamellar spacing, and the solvent-accessible cavities through steric hindrance. By comparison of 1–3, the [RMI]+ templates also have an effect on the properties. As the alkyl chains in [RMI]+ increase, the decomposing temperatures increase, emission peaks around 400 nm blue shift, and the cavities of 1–3 decrease. 1–3 exhibit ferromagnetism with similar magnetic parameters, while 4 reveals antiferromagnetism.

A series of Eu3+-doped AgGd(MoO4)2 red phosphors with well-defined shape and size were prepared via a precipitation method at room temperature. The samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The crystallinity, particle size, morphology, and luminescent properties of the as-prepared products were tuned by controlling the reaction conditions such as the precipitation reagents used and the pH of the initial solution. XRD results showed that all of the synthesized samples adopted a pure tetragonal structure. The formation mechanism of AgGdMo2O8 was investigated in detail, and two intermediates were found to be essential. Photoluminescence properties of the as-prepared AgGd0.9Eu0.1(MoO4)2 phosphors under diverse experimental conditions were also studied systematically, and their emission spectra showed emission characteristic of Eu3+.

Yb3+ and Pr3+ co-doped BaRE2ZnO5 (RE=Y, Gd) up-conversion (UC) phosphors were successfully synthesized by a modified sol-gel method. The processing parameters and optimal concentration of Pr3+ and Yb3+ were determined. The structures and luminescent properties of samples were characterized by X-ray diffraction (XRD) and photoluminescence spectra (PL). With the excitation of 980 nm laser diode, UC spectra showed five prominent emission bands centered at 484, 514, 546, 656 and 670 nm, which were attributed to the 1I6→3H4, 3P1→3H4, 3P0→3H5, 3P0→3F2 and 3P0→3F3 transitions of Pr3+, respectively. In the light of the pump power dependence, the possible UC mechanism in Yb3+ and Pr3+ co-doped BaRE2ZnO5 (RE=Y, Gd) was proposed and discussed.

TiO 2 @ZrO 2 @Y 2 O 3 :Eu 3+ composite particles with a core–multishell structure were synthesized through the combination of a layer-by-layer (LBL) self-assembly method and a sol–gel process. The obtained samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and fluorescence spectrophotometry. The results showed that the composite particles had a core–multishell structure, spherical morphology, and a narrow size distribution. The presence of a ZrO 2 layer on the TiO 2 core can effectively prevent the reaction between the TiO 2 core and a Y 2 O 3 shell; the temperature for the reaction between the TiO 2 core and the Y 2 O 3 shell in the TiO 2 @ZrO 2 @Y 2 O 3 :Eu core–multishell phosphor can be elevated by 300 °C compared to that for TiO 2 @Y 2 O 3 :Eu. Upon excitation of the core–multishell particles in the ultraviolet (254 nm), the Eu 3+ ion in the Y 2 O 3 :Eu 3+ shell shows its characteristic red emission (611 nm, 5 D 0 → 7 F 2 ), and the photoluminescence (PL) intensity of the phosphor with the core–multishell structure was obviously greater than that of the core–shell TiO 2 @Y 2 O 3 :Eu phosphor.

The synthesis and up-conversion luminescence properties of new Yb 3+ /Er 3+ co-doped AgGd(W,Mo) 2 O 8 phosphors are reported in this paper. The phosphors were synthesized via the traditional high-temperature solid-state method and structurally characterized using X-ray powder diffraction, after which their luminescent properties were characterized via up-conversion spectroscopy. Green and red emissions centered at 525, 550, and 656 nm were observed when the phosphors were excited at 980 nm; these emissions are ascribed to 2 H 11/2 , 4 S 3/2 → 4 I 15/2 (green emission) and 4 F 9/2 → 4 I 15/2 (red emission) transitions of Er 3+ , respectively. The substitution of W 6+ with Mo 6+ clearly enhanced the up-conversion intensity. In addition, the strong green emission of the samples proved that AgGd(W,Mo) 2 O 8 is an excellent host material and has potential for applications in solar cells.