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A large number of antibiotics are entering the aquatic environment accompanying human and animal excreta, which will threaten the survival of aquatic organisms and even human health. It has been found that binary mixtures of aminoglycoside (AG) exhibit additive action and can be evaluated well by a classical model, concentration addition (CA) in our past study. Therefore, to investigate the toxicity interaction within multi-component mixtures of AG antibiotics, five antibiotics, kanamycin sulfate (KAN), neomycin sulfate (NEO), tobramycin (TOB), streptomycin sulfate (STS), and gentamicin sulfate (GEN), were selected to construct five-component mixture systems by a uniform design ray method. The toxic effects (luminescence inhibition) of single antibiotic and five-antibiotic mixture systems towards a photobacterium Vibrio qinghaiensis sp.-Q67 (V. qinghaiensis) in different exposure time (0.25, 2, 4, 8, and 12 h) were determined by the time-dependent microplate toxicity analysis method. The concentration-effect data were fitted by a nonlinear least square method, toxicity interaction within mixture systems was analyzed by a CA model, and the interaction intensity was characterized by deviation from the CA model (dCA). Besides, the toxicity mechanism of five antibiotics and their five-component mixtures to V. qinghaiensis was analyzed by electron microscopy. The results show that toxicity of five antibiotics and their five-component mixture systems to V. qinghaiensis is time-dependent and has strong long-term toxicity. Different from binary AG antibiotic mixture systems, five-antibiotic mixture systems exhibit obviously time-dependent synergism. In addition, toxicity of the five-antibiotic mixtures can be 1.4 times higher than that of the mixtures without synergisms at the same concentration level. According to dCA, synergism intensity (dCA) curves of rays move slowly from the high concentration region to the medium or lower one and the maximum dCA values also increase, decrease, or first increase, then decrease with the lengthening of exposure time. The inhibition activity and synergism intensity of mixture rays have good correlation with the concentration ratios of STS, the key component for synergism. The cell morphology of V. qinghaiensis indicates the strong toxicity of five antibiotics and their mixture rays is not due to the destruction of cell structure, but the inhibition of the light-emitting activity of the photobacterium.

A large number of antibiotics are entering the aquatic environment accompanying human and animal excreta, which will threaten the survival of aquatic organisms and even human health. It has been found that binary mixtures of aminoglycoside (AG) exhibit additive action and can be evaluated well by a classical model, concentration addition (CA) in our past study. Therefore, to investigate the toxicity interaction within multi-component mixtures of AG antibiotics, five antibiotics, kanamycin sulfate (KAN), neomycin sulfate (NEO), tobramycin (TOB), streptomycin sulfate (STS), and gentamicin sulfate (GEN), were selected to construct five-component mixture systems by a uniform design ray method. The toxic effects (luminescence inhibition) of single antibiotic and five-antibiotic mixture systems towards a photobacterium

White nanosheets, yellow nanoislands and purple nanorods of CeO2 have been synthesized by a hydrothermal method. Indirect and direct photon energies of CeO2 of the white nanosheets (1.8, 2.1 eV), yellow nanoislands (2.2, 2.4 eV) and purple nanorods (2.0, 2.2 eV) are demonstrated, respectively. The difference in the electron spin–orbit coupling states between Ce 3d and O 2p may play an important role in their band gap energies.

Non-volatile state-modulated resistive switching memory devices hold great promise for the next generation of memory chips. Herein we demonstrate the high resistance switching performance of an Ag/α-Fe2O3/FTO device made using a facile hydrothermal process to grow an α-Fe2O3 nanorod array on a fluorine-doped tin oxide substrate (FTO). The resistive switching behavior can be effectively controlled using white-light irradiation. In particular, the device possesses an OFF/ON-state resistance ratio of ∼104 with exceptional stability at room temperature. Our experimental results suggest that the resistive switching effect in the Ag/α-Fe2O3/FTO system mainly results from the formation of conductive filaments inside the α-Fe2O3 nanorods. This study not only demonstrates the great potential to explore new chemistry with tailored nanostructures for high resistive switching performance, but also sheds light on its important practical applications in nonvolatile multistate memory devices.

Monodispersed LaCO3OH microgears with a novel plum blossom-like structure are prepared by a simple, reliable, environmentally-friendly and glycerol-mediated solvothermal method for the first time. By studying the effect of the experimental parameters on the morphology of LaCO3OH structures, we find that urea and glycerol at high concentration play a significant role in the formation of the plum blossom-like LaCO3OH microgears. In addition, we observe that the morphology evolution of the LaCO3OH microgears is from wires, spheres composed of rods, to plum blossom-like products with the increase of reaction time. More importantly, PL results demonstrate that the LaCO3OH microgears show a stronger PL than that of other structures, such as wires and spheres.

Mesoporous 2-line ferrihydrite was synthesized through a facile precipitation method and was characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. The surface area of the obtained mesoporous 2-line ferrihydrite was 331.0 m2 g−1. The fluoride adsorption performance was investigated. Batch adsorption experiments were conducted to study the influence of various factors such as contact time, initial fluoride concentration, temperature, pH value and co-existing anions on the adsorption of fluoride. The fluoride adsorption process fitted well with the Langmuir model, and the maximum adsorption capacity was 23.89 mg g−1 at pH 7.0. It is worth mentioning that this adsorbent performed well over a considerably wide pH range of 3–9. The fluoride adsorption kinetics over the adsorbent can be well described by a pseudo-second-order kinetic model. Thermodynamic parameters including the Gibbs free energy, standard enthalpy and standard entropy were calculated, and the results suggested that the adsorption of fluoride on the mesoporous 2-line ferrihydrite was thermodynamically favorable and exothermic in nature. Furthermore, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that the surface hydroxyl groups play an important part in the fluoride removal process.

Resistive switching memory devices, in which the resistance can be modulated between two nonvolatile states by applying an electrical pulse, have been proposed as the fascinating candidates for next generation logic and nonvolatile memory devices. Herein we report on the observation of magnetic-field controlled resistive switching behaviors in the Ag/[BiFeO3/γ-Fe2O3]/FTO structure. Moreover, this resistive switching behavior can be modulated by white light. Therefore, such a resistive switching memory can be controlled simultaneously by voltage pulses, magnetic field and white light. This study is helpful for exploring the nonvolatile multistate memory devices manipulated by various means.

Relatively high cost and limited resources are limiting the broad applications of Li-ion batteries. Na-ion batteries are one of the most promising replacement candidates because of abundant sodium resources, low price and similarity with Li insertion chemistry. For the first time, γ-Fe2O3 film was grown directly on a copper sheet with radio frequency magnetron sputtering as an anode for Na-ion batteries. Results show that the γ-Fe2O3 film annealed at 600 °C delivers a high reversible capacity of 450 mA h g−1 and nearly 100% capacity retention over 100 charge–discharge cycles, significantly outperforming all the previously reported examples. It is believed that the high performance of the Na-ion anode can be attributed to high temperature annealing producing nanopores for a large ion-inserting surface area and uniform γ-Fe2O3 particles firmly loaded on the surface of the Cu substrate to robustly retain the film structure during the Na-ion intercalation process for long cycle life. This work holds great promise for the fabrication of inexpensive and non-toxic Na-ion batteries for practical applications.

The self-association of alcohols in water has been demonstrated by a number of special experiments and theoretical work. Here, we report a simple and effective method to investigate the presence of these hydrophobic aggregation areas. Porous ZnO nanostructures were prepared using a simple alcohol assisted solution synthetic method at room temperature. The presence of hydrophobic groups of alcohols resulted in the existence of microheterogeneities and organic aggregations in the mixed solution, which act as a soft template and play key roles in the formation of the porous structure of ZnO. A high reaction temperature resulted in decreased hydrogen bonding between the alcohol and water molecules, and increased hydrophobic interactions among the alcohol molecules as well as increased pore sizes of the ZnO nanostructures. Sphere-like and hexagonal pores were observed, which were a result of the in situ enwrapping of hydrophobic aggregation areas in alcohol aqueous solution.

The effect of stretching conditions, such as stretching ratios, temperatures and rates of extension, on the relative fraction of β-phase and electron structure as well as dielectric properties of poly(vinylidene fluoride) (PVDF) films was investigated. The fraction of β-phase in PVDF film increases greatly and reaches the peak of 93% after uniaxial stretching. Meanwhile, stretched spherulites and micro-strips paralleling with the stretching direction were observed in the matrix by atomic force microscopy (AFM). The results of fine structure of fluorine and carbon elements in PVDF, identified by X-ray absorption near edge structure (XANES), indicate that the coordination between F and H atoms of the adjacent chains is produced and thus enhances the dielectric response of the stretched film. As a result, the dielectric constant of the stretched film increases by 50% and achieves up to 12.1, as well as the dielectric loss being as low as 0.02.

In this paper, one-dimensional (1-D) dypingite (hydrated magnesium carbonate hydroxide, Mg5(CO3)4(OH)2·5H2O) nanowires with several hundreds micrometers in length were synthesized at 100 °C by a simple solution method without using any template or catalyst for the first time. A plausible diffusion growth model for the growth of the dypingite nanowires was proposed. The influences of the magnesium ion concentrations and the magnesium sources on the structures of the products were also studied. The as-synthesized nanowires were an excellent precursor for the fabrication of 1-D nanoporous magnesium oxide (MgO) nanowires via a simple thermal transformation process. Room temperature photoluminescence studies suggest that the nanoporous MgO nanowires show a strong ultraviolet emission and a weak blue emission. The adsorption properties of the porous MgO nanowires were investigated for As(V) removal. A high As(V) adsorption capacity of 384.6 mg g−1 was realized, which was resulted from the reaction between the As(V) species and MgO in aqueous solution.

Ultralong and uniform amorphous carbon nanotubes (ACNTs) were prepared by using a simple and environmental friendly hydrothermal method at low temperature. Factors affecting the growth of the ACNTs were systematically studied. A reasonable Ostwald ripening growth mechanism was proposed for the formation of the ACNTs. The as-prepared ACNTs were used as an adsorbent for the removal of methylene blue (MB) from aqueous solutions in two modes, batch and fixed bed. In the batch mode, the removal efficiency for MB was improved remarkably by increasing the contact time and the adsorbent dosage. High pH values were in favor of the adsorption for MB. The adsorption isotherm of the ACNTs was well fitted with Langmuir model, with square of correlation coefficient r2 > 0.9996. The maximum adsorption capacity (qm = 46.21 mg g−1) of the ACNTs was higher than that of the multi-walled carbon nanotubes (qm = 35.83 mg g−1). In addition, the adsorption kinetics results presented two adsorption stages. The rapid and the slow adsorption stages resulted from the adsorption of the external and the inner surface of the ACNTs, respectively. In the fixed-bed mode, the MB removal percentage increased with decreasing the flow rate and the concentration of MB. The results reveal that the as-prepared ACNTs can be employed as an adsorbent for the removal of organic pollutants from wastewater.