As a new and developing field, organic electronics is attracting much attention and has contributed greatly to progress in science and technology over the past few decades. Satisfactory results have been achieved for the use of organic optoelectronic materials in various electronic devices. As the most basic component used in electronic devices, organic optoelectronic materials have attracted an increasing amount of attention. Diazine compounds have excellent optical and electrical properties and are some of the most researched compounds in the photoelectric material field. They contain a benzene ring in which two of the C―H fragments have been replaced by isolobal nitrogen. Three isomers: pyridazine (1,2-diazine), pyrimidine (1,3-diazine), and pyrazine (1,4-diazine) exist. Because of the relative position of two of the N atoms, they can be modified in different positions and can be effectively used to control the electronic structure of the material. Therefore, they have received widespread attention. In this review, a summary of recent research progress into diazine compounds in different optoelectronic functional material application fields is provided. Specifically, photovoltaic materials, thin film semiconductor materials, liquid crystal materials, chemosensor materials, and electroluminescent materials are discussed. Finally, existing important problems and the future development of diazine compounds are also discussed.

With a view to understanding the argument of the phase transition mechanisms of D- and Lvaline around 270 K, the temperature dependences of the heat capacities of single crystals, ground powders, and polycrystalline products were investigated using differential scanning calorimetry. Endothermic transition peaks were observed at phase transition temperatures of 273.59 and 273.76 K for D- and L-valine single crystals, respectively with an energy difference of 0.18 J?mol^-1. The X-ray crystal fine structure of chiral valine was determined using Mo-K_α radiation (λ=0.071073 nm) on Nonius Kappa CCD diffractometer. D- and L-valine crystals were monoclinic, with the P2₁ space group, Z=4, lattice constants a= 0.96706(5)/0.96737(5) nm, b=0.52680(3)/0.52664(3) nm, and c=1.20256(7)/1.20196 (6) nm, and β=90.724(2)°/90.722(3)° at ~270 K. Two crystallographically independent molecules A (trans form) and B (gauche I from) were observed in the unit cell, these were rotational isomers with two different conformations. X ray diffraction at 293, 270, 223, and 173 K showed that the N―H, H…O bond lengths and the N―H…O bond angle of D- valine fluctuated at 270 K，but the intramolecular N―H…O hydrogen bond was stable and measurable. No evidence was obtained for a configuration transformation from D-valine to L-valine. Based on the clockwise and counterclockwise rotations of NH₃→CO₂ in the chiral valine crystals and the optical rotatory angle measurements, the intermolecular N⁺H…O^- hydrogen bond was electronic Cooper pairing and exhibited the spin superfluidity onto D-, L-, and DL- valine crystal lattices from 270 to 290 K upon the transition to the superconducting state.

The origin of weak ambiguous vibrational modes in surface enhanced Raman scattering (SERS), i.e., from the high-order effect or symmetry change using 1,4-benzenedithiol (BDT) as a probe, is investigated. Weak ambiguous vibrational modes are caused by symmetry change rather than high-order effect. The experimental method can be extended, e.g., to similar systems excited by lasers with different wavelengths, or microelectronic junctions bridged by organic molecules.

Predicting the reactivity of electrophilic substitution at different sites is of theoretical and practical significance, and many prediction methods based on the electronic structure of reactants have been proposed. We compared the reliability of 14 prediction methods, using 14 monosubstituted and 8 disubstituted benzenes as test sets. Methods reflecting local electronic softness, such as the Fukui function and average local ionization energy, are well-suited to monosubstituted benzenes with ortho-para directing groups and disubstituted benzenes. However, these methods often fail for systems containing a single meta directing group. Methods reflecting electrostatic effects perform worse overall than those reflecting local softness, but are better suited to systems containing a single meta directing group. Dual descriptor is the most overall robust method, and can be regarded as a universal prediction method.

Density functional theory (DFT) calculations were used to study the adsorption of noble metal (Pt) on deprotonated 1,3-dipolar cycloaddition graphene to explore the mechanism of the formation of metal nanowires. The results show that: (1) Pt atoms that adsorb on 1,3-dipolar cycloaddition graphene induce the deprotonation of this 1,3-dipolar cycloaddition graphene and then the configuration changes to a deprotonated 1,3-dipolar cycloaddition graphene; (2) the noble metal anchoring site on the deprotonated 1,3-dipolar cycloaddition graphene is the ortho-carbon of nitrogen in the deprotonated pyridine alkyne, which was further confirmed by the average Bader charge of the ortho-carbon, and the average Bader charge of the ortho-carbon is as high as 1.0e; (3) Pt_n nanowire can form between two neighboring deprotonated pyridine alkyne units of deprotonated 1,3-dipolar cycloaddition graphene, and the Pt_n (n=3-6) nanowire adsorption configurations are more stable than the corresponding Pt_n (n=3-6) cluster adsorption configurations; and (4) the electronic structure analysis of the composite shows that Pt metal adsorption does not essentially change the electronic property of deprotonated 1,3-dipolar cycloaddition graphene. The doped states of the Pt metal result in the Pt₆ cluster adsorption composite being metallic while the doped states result in the Pt6 nanowire adsorption composite being semimetallic.

A dissipative particle dynamics simulation was performed to study the influence of blending different linear triblock copolymers A_xB_yC_z and linear diblock copolymers A_mB_n in an aqueous solution on the morphology diversity of the formed multicompartment micelles. The chain lengths of the linear triblock copolymers and diblock copolymers were varied to find the conditions of the formation of multicompartment micelles. The multicompartment micelle morphologies formed by the different blends of linear triblock copolymer and linear diblock copolymer are various, such as "worm-like" micelles, "hamburger" micelles, "sphere on sphere" micelles, and "core-shell-corona" micelles etc. Controlling the overall morphology and inner structure of the multicompartment micelles was possible using binary blends of a linear triblock copolymer and a diblock copolymer. The density profiles and the pair distribution function were calculated to characterize the structures of the obtained multicompartment micelles. In this work, by blending a linear triblock copolymer and a linear diblock copolymer, complex multicompartment micelles were prepared and characterized. This work shows that simply blending linear triblock copolymers and linear diblock copolymers is an effective way to control the morphology and structure of multicompartment micelles. This is more economical and easy to form multicompartment micelles in the engineering experiments. Therefore, the blending of copolymers should be given more attention in future for the design of new multicompartment micelles.

An all-atom force field was developed and validated for three energetic materials 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3, 5,7-tetrazocine (HMX). The functional form of the force field is widely used. The valence parameters were derived by fitting the quantum mechanics data. The atomic charge and van der Waals (VDW) parameters were optimized by fitting experimental data such as densities and sublimation enthalpies of the molecular crystals. The force field was validated by calculating the molecular conformers in the gas phase and the physical properties of the molecular crystals. It is demonstrated that the force field performs well in predicting molecular structures, vibrational frequencies, lattice parameters, crystalline densities, and sublimation enthalpies. Further validation showed that the force field predicts the equation of states and the bulk modulus well.

The modification of a TiO₂/dye/electrolyte interface can effectively improve the performance of dyesensitized solar cells (DSCs). A variety of methods has been reported for the modification of this interface, among which the introduction of a small organic molecule co-adsorbed with the dye on the surface of TiO₂, which is simple and effective. In this paper, di-n-dodecylphosphinic acid (DDdPA) was synthesized and used as a coadsorbent in a Z907 based dye-sensitized solar cell. Its od adsorption property on the surface of TiO₂ film containing Z907 was confirmed by Fourier transform infrared (FT-IR) spectroscopy. The dynamic processes of electron transport and recombination were investigated by electrochemical impedance spectroscopy (EIS) and intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS). Compared with the widely used bis-(3,3-dimethyl-butyl)-phosphinic acid (DINHOP) coadsorbent, the DSC based on DDdPA is more effective in reducing electron recombination as shown by the EIS measurement, and this is mainly owed to the longer alkyl chain and the more pronounced steric hindrance effects. With an optimized concentration ratio of Z907 to DDdPA of 2:1, the charge transfer resistance (R_ct) is larger than that of the device with only Z907 and an optimized Z907-to-DINHOP ratio of 1:1. IMPS/IMVS measurements indicate that the introduction of DDdPA effectively enhances the electronic lifetime and leads to a negative shift of about 30 mV for the conduction band edge. With the optimized DDdPA concentration, the open-circuit photovoltage (V_oc) improved by 47 mV, and the power conversion efficiency of the DSC improved by 10%.

This research developed a novel composite co-precipitation method to prepare high performance LiNi_0.5Mn_1.5O₄ based on a traditional solid-state method. Ammonium oxalate/ammonium carbonate was used as a composite precipitator to deposit Ni/Mn ions. Combined with a facile hydrothermal treatment, stoichiometric LiNi_0.5Mn_1.5O₄ was obtained with a pure spinel structure and spherical hierarchical morphology. Electrochemical measurements indicate that the as-prepared LiNi_0.5Mn_1.5O₄ delivers a high capacity of 141.4 mAh·g^-1 and after 200 cycles under 0.3C, 1C, and 3C, the materials retained their capacities up to 96.3%, 94.4%, and 91.1%, respectively. Additionally, the capacity upon exposure to a low voltage of 4.0 V was efficiently eliminated by heat treatment and by a particular cooling process. Furthermore, the LiNi_0.5Mn_1.5O₄ materials with high energy and high power performances of 648.6 mWh·g^-1 and 7000mW·g^-1 were obtained because of different cation ordering.

The synergistic inhibition effect of the imidazoline ammonium salt (IAS) and sodium dodecyl sulfate (SDSH) on the corrosion of Q235 carbon steel in a CO₂ saturated brine solution was studied by weight loss, electrochemical impedance spectroscopy (EIS), Tafel polarization measurements, X-ray photoelectron spectrometry (XPS), and scanning electron microscopy (SEM). We found that in the CO₂ saturated brine solution, a od synergistic inhibition effect exists between IAS and low concentrations of SDSH, and the most significant synergistic inhibition occurred at a concentration ratio of 1:1 (50 mg·L^-1:50 mg·L^-1) with an inhibition efficiency of 88.5%. However, anta nism occurs upon mixing IAS with a high concentration of SDSH. In this paper, the mechanisms of the synergistic and anta nistic effects are analyzed using a reasonable adsorption model. od corrosion inhibition on Q235 carbon steel was also found when only using a high concentration of SDSH with an inhibition efficiency of about 90%. Both the adsorption processes of SDSH and IAS on the surface of Q235 carbon steel are spontaneous processes and the former process complies with the Frumkin adsorption model while the later complies with the Temkin adsorption model.

Based on the reaction mechanism of the electro-oxidation of sulfide on platinum, we propose a simplified model for studying the spatiotemporal dynamics on the electrode surface in the oscillatory region of the N-shaped negative differential resistance (N-NDR) through numerical simulation. Simple and complex current oscillations were observed during the homogeneous simulation, and these were caused by coupling between one positive feedback, i.e., double-layer potential autocatalysis, and two negative feedbacks consisting of a mass-transport limited step and a poison-adsorption process. To obtain a better simulation of the experimental situation, the transport of electroactive species in both the parallel and vertical directions of the electrode was taken into account to simulate pattern formation on the electrode. The model simulations gave complicated patterns including twinkling-eye patterns and traveling waves, which agree qualitatively with the experimental results and possess the same evolution principles. Meanwhile, for certain parameters more complex patterns were obtained, e.g., two-arm spiral waves of the double-layer potential. This opens an interesting perspective in the explanation and prediction of pattern formation in electrochemical systems.

Based on cationic and anionic surfactant mixed systems, ultra-low interfacial tension was achieved in the Karamay oil field systems. Upon the addition of a non-ionic third component, the solubility of the mixed cationic-anionic surfactant systems increased significantly. The mixed surfactant ratio and the concentration were determined by the application in the five areas of the Karamay oil field. The interfacial tension in some real systems was found to be around 10^-4 mN·m^-1. These cationic and anionic surfactant mixed systems have a super-resistance adsorption capacity. The results show that after 72 h of quartz adsorption, these systems can still reduce the interfacial tension to an ultra-low level.

The mixed micellization behavior of an amphiphilic antidepressant drug amitriptyline hydrochloride (AMT) in the presence of the conventional anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was studied at five different temperatures and compositions by the conductometric technique. The critical micelle concentration (cmc) and critical micelle concentration at the ideal state (cmc^id) values show mixed micelle formation between the components (i.e., drug and AOT). The micellar mole fractions of the AOT (X₁) values calculated using the Rubingh, Motomura, and Rodenas models show a higher contribution of AOT in the mixed micelles. The interaction parameter (β) is negative at all temperatures and the compositions show attractive interactions between the components. The activity coefficients (f₁ and f₂) calculated using the different proposed models are always less than unity indicating non-ideality in the systems. The ΔG_m^θ values were found to be negative for all the binary mixed systems. However, ΔH_m^θ values for the pure drug as well as the drug-AOT mixed systems are negative at lower temperatures (293.15-303.15 K) and positive at higher temperatures (308.15 K and above). The ΔS_m^θ values are positive at all temperatures but their magnitude was higher at T=308.15 K and above. The excess free energy of mixing (ΔG_ex) determined using the different proposed models also explains the stability of the mixed micelles compared to the pure drug (AMT) and surfactant micelles.

Quasi-concave Pt-Ni alloy nanostructures were synthesized via a solvothermal method, and were thought to form by epitaxial growth on the 12 vertexes of a cuboctahedron. A simultaneous etchin vergrowth process was proposed to illustrate the growth mechanism. The epitaxial layer was of different composition from the core, as confirmed by high-resolution transmission electron microscopy, selectedarea electron diffraction and powder X-ray diffraction characterizations. The concave structures exhibited high catalytic activity towards methanol oxidation. The mass-normalized catalytic activity of the concave products was ~3 times that of pure Pt nanoparticles synthesized under similar conditions, and 13.6 times that of commercial Pt/C. X-ray photoelectron spectroscopy characterization indicated that the binding energy of the concave structures shifted to lower energy, relative to the pure Pt. The modified electronic structure by introducing Ni was thought to be responsible for the enhanced catalytic activity.

Ametal-organic framework (MOF) material MIL-53(Al) (MIL: Materials of Institut Lavoisier) with high thermal stability was prepared by the solvothermal method, and it served as a support material for a cobalt catalyst in the CO oxidation reaction. A comparison between the catalytic performance of the MIL-53(Al) and the Al₂O₃ support material was carried out to understand the catalytic behavior of the catalysts. The catalysts were characterized by thermogravimetric-differential scanning calorimeter (TG-DSC), Fourier-transform infrared (FTIR) spectroscopy, N₂ adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), and hydrogen temperature-programmed reduction (H₂-TPR). The TG and N₂ adsorption-desorption analyses showed that MIL-53(Al) had od stability and high surface area. XRD and TEM results indicated that the size of the Co₃O₄ nanoparticles (5.03 nm) supported on MIL-53(Al) was smaller than that (7.83 nm) on the Al₂O₃ support. The highly dispersed Co₃O₄ nanoparticles from the three-dimensional porous structure of MIL-53(Al) led to superior catalytic activity during CO oxidation. The H₂-TPR spectra showed that the reduction in temperature of the Co/MIL-53(Al) catalyst was significantly lower than that of the Co/Al₂O₃ catalyst, implying a higher catalytic activity for the Co/MIL-53(Al) catalyst. Indeed, the heterogeneous catalytic composite material Co/MIL-53(Al) catalyst exhibited much higher activity than the Co/Al₂O₃ catalyst in the CO oxidation test with 98% conversion at 160 ℃ and 100% conversion at 180 ℃. The catalytic activity and structure of the Co/MIL-53(Al) catalyst were stable during the reaction.

Catalysts were prepared by adding different types of promoter (Co, Ir, or Pt) to the supported nickel catalyst NiMgAl samples. These catalysts were characterized by H₂ temperature-programmed reduction (H₂-TPR), CO₂/CH₄ temperature-programmed surface reactions (CO₂/CH₄-TPSR), and CO₂ temperatureprogrammed desorption (CO₂-TPD). The effects of the catalyst structure on catalytic performance in the methane dry reforming reaction with carbon dioxide were investigated. The addition of a small amount of promoter (Pt or Ir) can lower the reduction temperature of the nickel active component, and enhance performance in the methane dry reforming reaction. The catalysts with Co or Ir promoter feature lower activation energies than the unmodified NiMgAl catalyst. The activation energy was 51.8 kJ·mol^-1 for the NiMgAl sample, decreasing to 26.4 kJ·mol^-1 for the NiPtMgAl catalyst, which showed overall better catalytic performance. Results of CH₄-TPSR and CO₂-TPSR demonstrate that the NiPtMgAl catalyst can generate more active carbon species on the catalyst surface. The CO₂-TPD results show that adding a promoter can increase the CO₂ adsorbed/desorbed amount compared with the unmodified NiMgAl catalyst over the same reaction temperature range.

Ag/Ag₃PO₄/g-C₃N₄ (g denotes graphitic) was synthesized via an anion-exchange precipitation method, and its photocatalytic activity under visible light and regeneration with H₂O₂ and NaNH₄HPO₄ were investigated. The structural characteristics were analyzed using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS). The XRD results showed that the structure of the regenerated catalyst was unchanged. The FESEM and UV-Vis absorption spectroscopy results showed that the Ag/Ag₃PO₄/g-C₃N₄ catalyst was composed of Ag₃PO₄ and g-C₃N₄. XPS showed that a small amount of Ag particles were present on the catalyst surface. The photocatalytic activity was evaluated using phenol degradation under visible light (λ>420 nm) and the photocatalytic mechanism was discussed based on the active species during the photocatalytic process and the band structure. Experimental studies showed that the photocatalytic activity of the as-prepared Ag/Ag₃PO₄/g-C₃N₄ was higher than those of pure Ag₃PO₄ and g-C₃N₄. The high photocatalytic performance of the Ag/Ag₃PO₄/g-C₃N₄ composite can be attributed to the synergistic effect of Ag₃PO₄, g-C₃N₄, and a small amount of Ag⁰. Regeneration using H₂O₂ and NaNH₄HPO₄? 4H₂O fully restored the photoactivity of the catalyst, showing that this green regeneration method could make Ag/Ag₃PO₄/g-C₃N₄ an environmentally friendly catalyst for practical applications.

At ambient pressure, the effect of plasma discharge mode and reactor structure on ammonia decomposition to hydrogen was investigated. Dielectric barrier discharge (DBD) and alternating current (AC) arc discharge were produced upon adjusting the structure of the plasma reactor. By studying the discharge images, the voltage-current waveforms and the optical emission spectra in two discharge modes, we found that the AC arc discharge was a spatially partially stronger discharge compared with DBD. The AC arc discharge had a higher power efficiency and higher electron density than the dielectric barrier discharge. The ammonia molecules were mainly transformed into NH₃^* in an electronic excited state, and the N―H bond ruptured upon collision with a high-energy electron in DBD. However, electrons with a high average electron energy upon AC arc discharge can rupture the N―H bond directly to form highly active NH₂ and NH species, which can enhance the ammonia decomposition reaction. Results show that AC arc discharge had better performance toward ammonia decomposition than dielectric barrier discharge. The ability of different reactor structures to decompose ammonia under AC arc discharge increased in the following order: tube-tube>tube-flat>point-flat>flat-flat. The ammonia conversion can be as high as 60% under the tube-tube AC arc discharge with an input power of 30 W and a gap distance of 6 mm, while it was only 4% under the flat-flat dielectric barrier discharge.

Nitrobenzoic acid (NBA) was bound to the side chains of polystyrene (PS) to give nitrobenzoic acidfunctionalized polystyrene (PS-NBA). By a coordination reaction of PS-NBA and a Eu³⁺ ion, a binary polymerrare earth complex PS-(NBA)₃-Eu(Ⅲ) was prepared. Additionally, with phenanthroline (Phen) as a small molecular ligand, the ternary polymer-rare earth complex PS-(NBA)₃-Eu(Ⅲ)-Phen₁ was also prepared. In this work, the influence of the nitro-substituted aromatic ring on the photoluminescence properties of the polymerrare earth complexes of benzoic acid (BA)-functionalized polystyrene and a Eu³⁺ ion were studied. The experimental results show that the nitro-substituted benzene ring had a twofold influence on the photoluminescence properties of the polymer-rare earth complexes of the benzoic acid-functionalized polystyrene and the Eu(Ⅲ) ion. Upon an intraligand charge transfer (ILCT), the nitro substituent causes the excitation energy of the BA ligand to dissipate and causes the triplet state energy of the BA ligand to decrease. As a result, the match between the lowest triplet level of the NBA ligand and the resonance energy level of the Eu(Ⅲ) ion improved significantly. The NBA ligand strongly sensitized the florescence emission of the Eu(Ⅲ) ion leading to the PS-(NBA)₃-Eu(Ⅲ) and PS-(NBA)₃-Eu(Ⅲ)-Phen₁ complexes producing strong florescence emission, which shows the positive effect of the nitro-substituted benzene ring on the luminescence properties of the complexes. However, even though the solution of the complex was dilute the florescence emissions of the complexes weakened with an increase in the concentration of the complexes from 4.0×10^-4 to 4.0×10^-6 mol·L^-4. This was caused by fluorescence resonance energy transfer (FRET) in which the fluorescence resonance energy of the excited complex was transferred to the nitro group as an‘acceptor’species. This indicates a negative effect of the nitro substituent on the benzene ring on the luminescence properties of the complexes.

The strength of industrial carbon fibers (CFs) is far lower than their theoretical strength because of defects in the microstructure of carbon fibers and these are the main restrictions in improving their performance. The most effective way to improve the strength of CFs is to reduce the amount of these defects. We thus report a novel method using a liquid oli mer of acrylonitrile (LAN) to modify the defects. Briefly, Polyacrylonitrile (PAN)-based CFs T300 were infused into LAN, and subsequently oxidized in air and carbonized in nitrogen. Their tensile strength increased by 25%. Two-dimensional small angle X-ray scattering (SAXS) was used to characterize the variation in length of the microvoids (L), the chord length of cross section l_p, the orientation angle (B_eq), and the relative volume (V_rel). The results show that the length, orientation, angle and relative volume of the microvoids were much lower and the tensile property improved. The improvement in the tensile property comes from the modification of defects in CFs T300 by LAN. The BET method and scanning electron microscopy (SEM) were used to characterize the specific surface area and the morphology of T300 before and after LAN treatment. The results show that after the treatment of LAN the specific surface area decreased and the amount of surface defects also decreased.We further prove that the liquid oli mer of acrylonitrile can modify the defects in CFs. X-ray photoelectron spectroscopy (XPS) was used to study the chemical composition of LAN-treated CF surfaces. The results show that the relative content of oxygen-containing functional groups on the surface of the CFs (C―OH, C＝O, HO―C＝O) increased significantly. The increase in oxygen-containing groups enhanced the surface polarity of the CFs, improving the interaction between the treated CFs and the epoxy resin, which acts as a carbon fiber substrate. Therefore, the mechanical properties of the CFs improved.

The sol-gel method was used for the synthesis of BiVO₄ hollow nanospheres by employing carbon spheres as a hard template. CuO loaded composite photocatalysts were prepared by impregnation. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), Tafel polarization curves (Tafel), linear sweep voltammetry (LSV), monochromatic incident photon to current conversion efficiency (IPCE), and UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS). We found that the BET surface area of the BiVO₄ hollow nanospheres (10.24 m²·g^-1) was 5.20 times that of the amorphous form of BiVO₄ (1.97 m²·g^-1). A p-n heterojunction was formed between CuO and BiVO₄. Samples with 5% CuO exhibited optimal photoelectrochemical performance. They had a higher corrosion current density (12.33 times as much as that of the BiVO₄ hollow nanospheres), and a smaller band gap (2.30 eV). Toluene was chosen as a model pollutant to evaluate the removal capacity and the CO₂ mineralization rate of volatile organic compounds under visible light. The samples doped with 5% CuO exhibited optimal visible-light photocatalytic activity, with an 85.0% toluene degradation efficiency and a 12.0% mineralization rate in 6 h.

Highly ordered [NiFe/Cu/Co/Cu]_n multilayer nanowire arrays were successfully prepared by a combination of electrodeposition and the anodic aluminum oxide (AAO) template method. The crystalline structures obtained at different annealing temperatures were characterized by high-angle X-ray diffraction (XRD). The coercivity, remanence ratio, giant magneto resistive (GMR), and magnetic sensitivity of the [NiFe/Cu/Co/Cu]_n multilayer nanowire arrays were investigated at different annealing temperatures. After heating, the multilayer nanowires magnetic microcrystalline orientation was more obvious and the crystal structure was more uniform. The multilayer nanowires coercivity and remanence ratio increased initially and then decreased at 300 ℃. A maximum coercivity and GMR value of 59% was achieved with a magnetic sensitivity of up to 0.233% Oe^-1 at 300 ℃.

GdAlO₃:Er³⁺,Yb³⁺ phosphor was prepared by coprecipitation, sol-gel, and solid-state reaction methods, respectively. The effects of the preparation method on the structures, morphologies, surface species, light absorption, and up-conversion photoluminescence (UCPL) of the phosphors were investigated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, N₂ physisorption, absorption spectroscopy, and UCPL spectroscopy. The results showed that preparation using coprecipitation method gave a pure-phase GdAlO₃:Er³⁺,Yb³⁺ phosphor under milder conditions than those needed for the sol-gel or solid-state reactions. The particles of the phosphors prepared by coprecipitation and sol-gel methods were nanometer sized, and severe particle agglomeration occurred for the sol-gel sample. In contrast, the phosphor particles obtained using the solid-state reaction method were micrometer sized. Under excitation with 980 nm IR radiation, bright green UCPL at wavelengths of 524 and 546 nm, and red UCPL at 659 nm, were observed, with the green emission being dominant, irrespective of the preparation method. A comparison of the UCPL spectra of the phosphors prepared by different methods showed that the phosphor prepared by coprecipitation method showed a much higher emission intensity than the others, and the phosphor prepared by the sol-gel method gave the largest ratio of red to green emission intensities. The FTIR results showed that the phosphor prepared by the sol-gel method had larger amounts of surface CO₂, CO₃^2-, and OH^- species. Based on the FTIR spectra, the UCPL results for phosphors with different concentrations of Er³⁺ and Yb³⁺ as well as the power dependences of UCPL intensities, the energy transfer processes between Yb³⁺ and Er³⁺ ions, and UCPL of the GdAlO₃:Er³⁺, Yb³⁺ phosphors prepared by different methods were discussed.

SnO₂ nanofibers were fabricated by electrospinning, using SnCl₂ ·2H₂O as the raw material. The influences of ZnO doping on the morphologies, structures, and compositions of the SnO₂ nanofibers were studied by introducing different amounts of ZnO into the SnO₂. The crystallography and microstructures of the synthesized SnO₂/ZnO composite nanofibers with different molar ratios of Sn to Zn were investigated using thermogravimetric/differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The obtained SnO₂/ZnO composite nanofibers with different ZnO contents had hollow hierarchical structures composed of nanocrystals. Different amounts of ZnO gave different structures. The characterization results showed that the introduction of ZnO into SnO₂ played an important role in the SnO₂ nanofiber structure. The gas sensing properties of sensors based on different ZnO-doped SnO₂ nanofibers were tested. The results indicated that the methanol-sensing performance of the sensor containing SnO₂/ZnO in a molar ratio of 1:1 was better than those of the others. The sensing mechanisms of ZnO-doped SnO₂ nanofibers were examined in detail. Possible reasons for the enhanced SnO₂ nanofibers were fabricated by electrospinning, using SnCl₂ ?2H₂O as the raw material. The influences of ZnO doping on the morphologies, structures, and compositions of the SnO₂ nanofibers were studied by introducing different amounts of ZnO into the SnO₂. The crystallography and microstructures of the synthesized SnO₂/ZnO composite nanofibers with different molar ratios of Sn to Zn were investigated using thermogravimetric/differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The obtained SnO₂/ZnO composite nanofibers with different ZnO contents had hollow hierarchical structures composed of nanocrystals. Different amounts of ZnO gave different structures. The characterization results showed that the introduction of ZnO into SnO₂ played an important role in the SnO₂ nanofiber structure. The gas sensing properties of sensors based on different ZnO-doped SnO₂ nanofibers were tested. The results indicated that the methanol-sensing performance of the sensor containing SnO₂/ZnO in a molar ratio of 1:1 was better than those of the others. The sensing mechanisms of ZnO-doped SnO₂ nanofibers were examined in detail. Possible reasons for the enhanced

Mesoporous ethane-silica nanotubes (E-SNTs) were synthesized using P123 as a template and 1,2-bis(trimethoxysilyl)ethane (BTME) as a silica source. E-SNTs were modified with polyethylenimine (PEI) as sorbents for CO₂ adsorption. These new composite sorbents were characterized by transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier transform infrared (FTIR) spectroscopy, and thermal gravimetric analysis (TGA). We found that 75 ℃ is the optimal temperature for CO₂ adsorption. E-SNTs with a 50% (w) PEI loading (E-SNTs-50) exhibited a higher CO₂ adsorption capacity (3.32 mmol·g^-1) than the other materials. The E-SNTs-based sorbents show better CO₂ capture performance than the SBA-15-based sorbents. Additionally, CO₂ uptake was further enhanced to 3.75 mmol·g^-1 in the presence of moisture. Cyclic CO₂ adsorption-desorption test results indicated that the composite sorbents are stable and can be regenerated.