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Selective removal of petroleum hydrocarbons (PHCs) from soil washing effluents is the key to the surfactant-enhanced soil washing technology. In this study, the diatomite was modified by nonionic surfactant TX-100 and applied in the selective adsorption of PHCs in the soil washing effluents. The modified diatomites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption/desorption and X-ray photoelectron spectroscopy respectively. The adsorption process followed the pseudo-second-order model and the adsorption isotherms indicated that the interaction between PHCs and modified diatomite was monolayer adsorption. The important operating factors such as TX-100 dosage, adsorbent dosage, time and temperature were optimized. With the participation of the low-cost adsorbent TX3-Db with high adsorption capacity, the recovery efficiency of the washing effluents was still up to 78.9% after three cycles. A selective adsorption mechanism, based on steric hindrance and electrostatic repulsion, was proposed to explain the removal of PHCs from washing effluents.

The aim of the study was to identify the effects of combined motor imagery and action observation therapy on vascular cognitive impairment.Thirty vascular cognitive impairment patients were randomly assigned into three groups. Cognitive training group was given conventional cognitive training, motor imagery + action observation group was treated with motor imagery and action observation therapy, and mixed therapy group was given conventional cognitive training and motor imagery + action observation therapy, for 8 wks continuously. The Montreal Cognitive Assessment Scale, Rivermead Behavioral Memory Test, and event-related potential were used to evaluate the cognitive function at baseline, 4- and 8-wk posttreatment, and 1-mo follow-up.There were significant time × group interactions in Montreal Cognitive Assessment Scale (F6,4.20 = 8.38, P0.001), event-related potential latent period (F6,294.24 = 5.10, P0.001), event-related potential amplitude (F6,1.68 = 23.08, P0.001), and Rivermead Behavioral Memory Test (F6,312.61 = 5.42, P0.001). Intragroup comparisons showed that Montreal Cognitive Assessment Scale and Rivermead Behavioral Memory Test scores and event-related potential amplitude increased significantly (P0.05), and event-related potential latency decreased significantly (P0.05) in all groups. Intergroup comparisons showed that the changes of all outcomes in mixed therapy group were greater than those in cognitive training and motor imagery + action observation group (P0.05) after treatment.These results suggest that the combination of cognitive training with motor imagery and action observation therapy is an effective treatment on cognitive function in people with vascular cognitive impairment.

Low-temperature molten-salt method and the NH 4 NO 3 flux were developed to synthesize quasi-spherical cubic BaGdF 5 :Ce 3+ /Er 3+ /Yb 3+ nanocrystals with the average diameter of 30 nm. The optimum doping concentrations of Er 3+ and Yb 3+ are determined to 2 and 20 mol%, respectively. The introduction of Ce 3+ in BaGdF 5 : Er 3+ /Yb 3+ nanocrystals deduced a huge variation of the profile of the UC emission under 976 nm laser irradiation. The strong ultraviolet UC emission of 330–380 nm is due to the overlap of 4 G 7/2 , 2 K 15/2 , 4 G 9/2 → 4 I 15/2 transitions of Er 3+ , and strong blue one locating at 440–480 nm is attributed to the overlap of 4 F 3/2, 4 F 5/2 → 4 I 15/2 and 4 G 7/2 , 2 K 15/2 , 4 G 9/2 → 4 I 13/2 transitions of Er 3+ , respectively. The UC emission mechanism and energy transfer process of BaGdF 5 :Ce 3+ /Er 3+ /Yb 3+ nanocrystals were provided in detail and demonstrated by the fluorescence decay curves and pumping power dependent UC emission spectra. This work not only demonstrates a rational approach to tailor UC emission (red, blue and ultraviolet) by tuning doping ions and concentration, but also for better understanding of their essential UC luminescence properties.

A series of NaBiF4:Er3+/Yb3+ micro-/nanocrystals were synthesized via the low-temperature molten-salt method in NH4NO3 flux. The influences of the amount of NaF and NH4NO3 flux used, the reaction time and reaction temperature on the crystal phase structure, morphology and size of the resultant samples were systematically investigated. The morphology, size, doped concentrations of Er3+ and Yb3+, pumping power, and temperature dependences of UC emissions were studied in detail under 980 nm irradiation. The NaBiF4:3 mol% Er3+/20 mol% Yb3+ crystal exhibits the strongest green UC emission, which was observed under several mW 980 nm excitation at room temperature. The energy transfer between Bi3+ and Er3+ during UC emission process was also discussed at length.