Research hotspots and trends in nursing education from 2014 to 2020: A co-word analysis based on keywords.

AIMS: To investigate research hotspots and trends in nursing education from 2014 to 2020, and provide references for researchers to understand the research status and developing trends in this field. DESIGN: A co-word analysis based on keywords. METHODS: Data were obtained from nursing education-related academic research articles that were retrieved through a literature search using PubMed during the period of 2014-2020. Keywords included in the analysis of literature were considered as the research objects. Bibliographic Item Co-occurrence Matrix Builder (BICOMB) was employed to extract high-frequency keywords and generate co-occurrence matrix, graphical clustering toolkit (gCLUTO) was used to perform cluster analysis, and SPSS 25.0 was used to perform strategic diagram analysis. RESULTS: Overall, 7857 articles were retrieved, from which 2679 keywords were obtained and 64 high-frequency keywords extracted. The results revealed seven hotspots in nursing education during the period of 2014-2020, which included research on: (i) continuing education in nursing, (ii) application and influence of the internet in nursing education, (iii) postgraduate nursing education, (iv) undergraduate nursing education and clinical quality training, (v) current development status and tendency of nursing education, (vi) nursing teaching methods and (vii) organization and management in nursing education. CONCLUSION: The seven research hotspots could reflect the publication trends in nursing education. By providing a co-word analysis-including cluster and strategic diagram analysis-an overall command of the latest hotspots can be depicted, and researchers conducting research in nursing education can have some hints. IMPACT: This study allows the development of future research on nursing education. Future researchers should explore the application of new network technologies in the process of nursing teaching, quality of postgraduate nursing education, innovative teaching methods as well as teaching strategies of improving students' clinical ability, current situation of economics and leadership in nursing education and ability of organization and management in undergraduate nursing education.

Structural, thermal and broadband NIR emission properties of Nd3+/Pr3+/Ag NPs co-doped tellurite glass.

Nd3+/Pr3+ co-doped tellurite glasses containing metallic Ag NPs were synthesized by melt-quenching and heat-treating techniques. The amorphous structural nature, fundamental vibrational units and good thermal stability of the prepared tellurite glasses were confirmed by X-ray diffraction (XRD) pattern, Raman spectrum and differential scanning calorimeter (DSC) curve, respectively. The precipitated Ag NPs in a glass matrix with an average diameter ∼5 nm were revealed by transmission electron microscopy (TEM) image, and the radiative property of Nd3+ and Pr3+ ions was evaluated from the absorption spectrum by Judd-Ofelt theory. Under the excitation of 488 nm Xenon lamp, two broadband near-infrared emissions covering 800-1100 nm and 1250-1650 nm ranges were observed from the fluorescence spectrum. The former originated from the transitions of Pr3+:3P1,0→1G4, Pr3+:1D2→3F4,3, Nd3+:4F3/2→4I11/2 and Nd3+:4F3/2→4I9/2, while the latter was contributed by the Pr3+:1G4→3H5, Pr3+:1D2→1G4, Pr3+:3F3→3H4 and Nd3+:4F3/2→4I13/2 transitions. With the introduction of Ag NPs, the emission intensity of two broadband near-infrared emissions was further enhanced, in which the peak emission intensity of 1250-1650 nm band was increased by about 56% and the FWHM is up to 250 nm. The obtained results indicate that Nd3+/Pr3+/Ag NPs co-doped tellurite glass has great potential in realizing ultra-broadband near-infrared emission covering O-, E- and S-bands simultaneously.

Ultra-broadband 1.0 µm band emission spectroscopy in Pr3+/Nd3+/Yb3+ tri-doped tellurite glass.

Tellurite glasses doped with trivalent Pr3+, Nd3+ and Yb3+ ions were prepared using conventional high-temperature melt-quenching technique and their optical absorption, near-infrared emission, X-ray diffraction (XRD), Raman spectrum, and differential scanning calorimeter (DSC) curve were measured. Upon excitation at 488 nm, an ultra-broadband near-infrared emission extending from 800 to 1120 nm was found to appear owing to the overlapping of the emission bands centered at 900 and 1035 nm of Pr3+, 880 and 1060 nm of Nd3+ as well as 978 nm of Yb3+, respectively. The energy transfer mechanism among Pr3+, Nd3+ and Yb3+ ions which was responsible for the observed ultra-broadband near-infrared emission was investigated to understand the luminescent phenomena. In addition, Judd-Ofelt theory was applied to predict the radiative properties of doped rare-earth ions, and some important radiative parameters such as radiative transition probability, branching ratio and radiative lifetime were derived. Meanwhile, the structural information of amorphous nature and vibrational units was revealed by the XRD pattern and Raman spectrum. Also, the DSC curve displayed the good thermal stability to resist thermal damage for studied tellurite glass with high glass transition temperature. The results indicate that Pr3+/Nd3+/Yb3+ tri-doped tellurite glass is a promising material for ultra-broadband fiber lasers operating around 1.0 µm near-infrared band.

No-Reference Image Blur Assessment Based on Discrete Orthogonal Moments.

Blur is a key determinant in the perception of image quality. Generally, blur causes spread of edges, which leads to shape changes in images. Discrete orthogonal moments have been widely studied as effective shape descriptors. Intuitively, blur can be represented using discrete moments since noticeable blur affects the magnitudes of moments of an image. With this consideration, this paper presents a blind image blur evaluation algorithm based on discrete Tchebichef moments. The gradient of a blurred image is first computed to account for the shape, which is more effective for blur representation. Then the gradient image is divided into equal-size blocks and the Tchebichef moments are calculated to characterize image shape. The energy of a block is computed as the sum of squared non-DC moment values. Finally, the proposed image blur score is defined as the variance-normalized moment energy, which is computed with the guidance of a visual saliency model to adapt to the characteristic of human visual system. The performance of the proposed method is evaluated on four public image quality databases. The experimental results demonstrate that our method can produce blur scores highly consistent with subjective evaluations. It also outperforms the state-of-the-art image blur metrics and several general-purpose no-reference quality metrics.

Optical and crystallization behavior in Dy3+ doped 40GeSe2-25Ga2Se3-35CsI glass.

Dy(3+) doped 40GeSe(2)-25Ga(2)Se(3)-35CsI (GGC) glass was synthesized, and optical spectrum, such as infrared transmission and Vis-Nir absorption was measured. Base on the Judd-Ofelt theory, the three Judd-Ofelt parameters Omega(t) (t=2, 4, 6) were calculated and the results were compared with other chalcogenide glasses. The small Omega(2) in GGC glass is ascribed to the weak covalency of Se-Dy bond. The theory of crystallization kinetics under non-isothermal condition was developed, and was applied to analyze this Dy(3+) doped GGC glass. From the heating-rate dependence of crystallization temperature, the activation energy for crystallization E=148 kJ/mol is obtained, and this value is much smaller than that of the undoped glass host, indicating the introduction of Dy(3+) ions into the GGC glass will get the host crystallized easily.