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AIMS To understand how survivors of stroke perceive secondary prevention and explore their perceived barriers and facilitators using the Theoretical Domains Framework. DESIGN A qualitative descriptive study. METHODS Nineteen survivors of stroke from three hospitals were recruited and interviewed from April 2019 to April 2020. The data were analysed deductively and inductively by content analysis strategies. RESULTS Three main themes of perception of secondary prevention were identified, these being active treatment-seeking, attention to taking medications and negative attitude towards lifestyle changes. Using deductive analysis, eight domains of the Theoretical Domains Framework were reported to be relevant in the secondary prevention behaviour of survivors of stroke that mapped to five 'barrier' domains (i.e. knowledge, physical skills, beliefs about capability, beliefs about consequences and optimism) as well as six 'facilitator' domains (i.e. knowledge, interpersonal skills, beliefs about capability, intention, emotion and social influences). Using inductive analysis we identified two additional important factors not falling in the domains of the Theoretical Domains Framework. These comprised female spouses' support and patients' economic autonomy, both of which could be classified as a facilitator or barrier. CONCLUSION Survivors of stroke perceive seeking treatment and using preventive medication as more important than modifying lifestyle behaviours. Knowledge and insight into the barriers and facilitators of secondary prevention in this specific context provides a theoretical and practical basis for the design of future secondary prevention interventions. IMPACT Stroke survivors' perceptions of secondary prevention, barriers and facilitators were explored in the context of a developing country. These findings highlight the need to better communicate the importance of improving lifestyle modification and medication adherence, and provide evidence for designing relevant interventions for stroke management in the community.

Well-crystallized α-Al2O3/TiC composite coating was synthesized on the surface of steel substrate by a facile laser-assisted combustion synthesis technique without subsequent calcination. The effect of laser cladding speed on formation and microstructure of the coatings was studied. At 6 mm/s, α-Al2O3/TiC coating with good quality was obtained without pores and cracks and was well bonded with the steel substrate. By adjusting the precoating thickness, the coating thickness was easily controlled. As a simple, environmentally friendly and energy-saving technique, laser-assisted combustion synthesis is expected to find applications in ceramic coating fabrication as tritium permeation barrier or wear- and corrosion-resistance coatings.

A1.95ZnSi2O7:Eu0.053+ (A=Ca, Sr, Ba) red phosphors were prepared by combustion-assisted synthesis method and their efficient red emission under near ultraviolet (UV) were observed. The luminescence and crystallinity were investigated using luminescence spectrometry and X-ray diffractometer, respectively. The emission spectrum shows that the most intense peak is located at 614 nm, which corresponds to the 5D0→7F2 transition of Eu3+. These phosphors have two main excitation peaks located at 394 and 465 nm, which match the emission of UV and blue light-emitting diodes, respectively. Thus, these phosphors could be used as red components for white light-emitting diodes.

Ba2−xMg1−yZnySi2O7:Eux2+ blue–green phosphor particles were prepared by combustion-assisted synthesis method as the fluorescent material for ultraviolet light-emitting diodes (UV-LEDs), performing as a light source. The luminescent properties were investigated by changing the postannealing temperature, the concentration of the activator, and the ratio of Zn to Mg. The crystallinity and luminescence were investigated by using an X-ray diffractometer and a luminescence spectrometer. The pure monoclinic Ba2MgSi2O7 and Ba2ZnSi2O7 phases were formed when the posttreatment temperature was 1000°C. It was found that the introduction of Zn2+ into Ba2MgSi2O7:Eu2+ effectively increased its emission. The emission spectra presented an emission position red shift of up to 5 nm from Ba2Mg Si2O7:Eu2+ to Ba2ZnSi2O7:Eu2+, which is correlated with the effect of Zn2+ substituting for Mg2+ sites. The excitation spectrum of Ba2ZnSi2O7:Eu2+ was a broad-band extending from 260 to 465 nm, which matches the emission of UV-LEDs.

A blue―green emitting phosphor of the monoclinic Ba 2 MgSi 2 O 7 :Eu 2+ was prepared by the combustion-assisted synthesis method and an efficient bluish-green emission under from ultraviolet to visible light was observed. The luminescence, crystallinity and particle sizes were investigated by using luminescence spectrometry, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The emission spectrum shows a single intensive band centered at 498 nm, which corresponds to the 4f 6 5d 1 → 4f 7 transition of Eu 2+ . The excitation spectrum is a broad extending from 260 to 465 nm, which matches the emission of ultraviolet light-emitting diodes (UV-LEDs). The critical quenching concentration of Eu 2+ in Ba 2 MgSi 2 O 7 :Eu 2+ phosphor is about 0.05 mol. The corresponding concentration quenching mechanism is verified to be a dipole-dipole interaction. The result indicates that Ba 2 MgSi 2 O 7 :Eu 2+ can be potentially useful as a UV radiation-converting phosphor for white light-emitting diodes (LEDs).

A novel red-emitting phosphor Ba1.95ZnSi2O7:Eu0.053+, Bx3+ was prepared by combustion synthesis and an efficient red emission under near-ultraviolet (UV) was observed. The luminescence, crystallinity, and particle sizes were investigated using luminescence spectrometry, X-ray diffractometry, and scanning electron microscopy. The emission spectrum shows that the most intense peak is located at 614 nm, which corresponds to the 5D0→7F2 transition of Eu3+. The phosphor has two main excitation peaks located at 394 and 465 nm, which match the emission of UV and blue light-emitting diodes, respectively. The optical absorption spectra of Ba1.95 ZnSi2O7:Eu0.053+, B0.063+ exhibited a band-gap energy of 3.95 eV. The results showed that boric acid was effective in improving the luminescence intensity of Ba1.95ZnSi2O7:Eu0.053+, and the optimum molar ratio of boric acid to zinc nitrate was about 0.06. The phosphor Ba1.95ZnSi2O7:Eu0.053+, B0.063+ synthesized by the combustion method showed 1.8 times improved emission intensity compared with that of the Ba1.95ZnSi2O7:Eu0.053+ phosphor under λex=394 nm.

A novel blue green-emitting phosphor, Ba₂ZnSi₂O₇: Eu(2+), was prepared by combustion synthesis method and an efficient bluish green emission under from ultraviolet to visible light was observed. The emission spectrum shows a single intensive band centered at 503 nm, which corresponds to the 4f(6)5d(1) → 4f(7) transition of Eu(2+). The excitation spectrum is a broad band extending from 260 to 465 nm, which matches the emission of ultraviolet light-emitting diodes (UV-LEDs). The effect of doped Eu(2+) concentration on the emission intensity of Ba₂ZnSi₂O₇: Eu(2+) was also investigated. The result indicates that Ba₂ZnSi₂O₇: Eu(2+) can be potentially useful as a UV radiation-converting phosphor for white light-emitting diodes.

(Ba 2− x Eu x )ZnSi 2 O 7 blue–green phosphors were prepared by a sol–gel (SG) process. The crystallization processes of the phosphor precursors were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TG). The properties of the resulting phosphors were characterized by photoluminescence (PL) spectroscopy. The shape and size of the sample were observed by transmission electron microscopy (TEM). The results of TG and XRD indicate that the (Ba 2− x Eu x )ZnSi 2 O 7 phosphors crystallize completely at 900 °C. The emission spectrum shows a single band centered at 500 nm, which corresponds to the 4 f 6 5 d 1 → 4 f 7 transition of Eu 2+ . The excitation spectrum is a broad band extending from 260 to 465 nm, which matches the emission of ultraviolet light-emitting diodes (UV-LEDs). The critical quenching concentration of Eu 2+ in Ba 2 ZnSi 2 O 7 :Eu 2+ phosphor is about 0.10 mol. The value of the critical transfer distance is calculated as 15.1 A. The corresponding concentration quenching mechanism is verified to be the electric multipole–multipole interaction.

Long lasting alkaline earth silicates, Ba 2 ZnSi 2 O 7 :Eu, Dy, Ba 2 ZnSi 2 O 7 :Eu, Nd and Ba 2 ZnsSi 2 O 7 :Eu, Dy, Nd were prepared by the combustion-assisted synthesis (CAS) method. The obtained phosphors were characterized by means of X-ray diffraction (XRD) and their photoluminescence spectrum (PSL). The emission spectrum shows a single band centered at 503 nm, which corresponds to the 4f 6 5d 1 → 4f 7 transition of Eu 2+ . The Ba 2 ZnSi 2 O 7 :Eu phosphors showed blue-green afterglow ( λ em = 503 nm) when Dy 3+ and Nd 3+ ions were doped. The electron affinity (ea) value for Eu 2+ in [EuO 8 ] was calculated to be 1.63 eV. When the concentration quenching of Dy 3+ and Nd 3+ was over 0.07, the afterglow of the phosphors is enhanced.

Nondestructive monitoring and diagnosis of plant N status is necessary for precision N management. The present study was conducted to determine if canopy reflectance could be used to evaluate leaf N status in rice (Oryza saliva L.). Ground-based canopy spectral reflectance and N concentration and accumulation in leaves were measured over the entire rice growing season under various treatments of N fertilization, irrigation, and plant population. Analyses were made on the relationships of seasonal canopy spectral reflectance, ratio indices, and normalized difference indices to leaf N concentration and N accumulation in rice under different N treatments. The results showed that at each sampling date, leaf N concentration was negatively related to the reflectance at the green band (560 nm) while positively related to ratio index, with the best correlation at jointing. However, the relationships between leaf N accumulation and reflectance at green band and ratio index were consistent across the whole growth period. The ratio of near infrared (NIR) to green (R 810 /R 560 ) was especially linearly related to total leaf N accumulation, independent of N level and growth stage. Tests of the linear regression model with different field experiment data sets involving different plant densities, N fertilization, and irrigation treatments exhibited good agreement between the predicted and observed values, with an estimation accuracy of 96.69%, root mean square error of 0.7072, and relative error of -0.0052. These results indicate that the ratio index of NIR to green (R 810 /R 560 ) should be useful for nondestructive monitoring of N status in rice plants.