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A series of Na0.5Bi2.5Nb2−xTaxO9 (NBN2−xTx):Er3+/Yb3+ upconversion luminescence (UL) phosphors were prepared by a solid‐state sintering method, and the lattice structure of the prepared samples was studied by X‐ray diffraction. Under 980‐nm laser excitation, the UL properties were investigated by a spectrophotometer from room temperature to 723 K, and the optimal concentration of co‐doping Er3+/Yb3+ is 0.14 and 0.26 by replacing Bi3+ sites in NBN2−xTx host, respectively. With the increase of Ta5+ concentration, the color of UL gradually changes from green to yellow corresponding color coordinates from (0.301, 0.682) to (0.441, 0.549) under 980‐nm laser excitation. This color change is attributed to the decrease of lattice unit volume leading to the increase of cross relaxation of Er3+ to Er3+ and energy back transfer from Er3+ to Yb3+. Using the luminescence intensity ratio technique, the maximum absolute sensitivities (SA) are obtained as 0.00674 K−1 at 538 K and 0.00603 K−1 at 573 K, and relative sensitivities (SR) are obtained as 0.01174 K−1 at 303 K and 0.01244 K−1 at 303 K based on 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 energy level transitions of Er3+ in NBN2:0.14Er3+/0.26Yb3+ phosphors under 980‐ and 1550‐nm laser excitations, respectively. The results suggest that the NBN2−xTx:Er3+/Yb3+ phosphors are promising candidates for temperature sensing with different UL colors. [ABSTRACT FROM AUTHOR]

A series of Sr2.99‐x(PO4)2:.01Er3+/xYb3+ (x =.02,.04,.06,.08,.10) phosphors in the presence of impurity Tm3+ were synthesized by high temperature solid‐state method, and X‐ray diffraction results show that these samples are pure R‐3 m(166) space group phase. The upconversion luminescence (UCL) of Er3+ and impurity Tm3+ under 980‐nm laser excitation were investigated, and the results show that the intense blue UCL of impurity Tm3+ and thermal enhancement of 2H11/2→4I15/2 of Er3+ simultaneously exist. When Er3+ doping concentration is kept at.01, both the blue UCL intensity of impurity Tm3+ and green and red UCL intensity of Er3+ reach the maximum at Yb3+ doping concentration of.08. The thermal enhancement effect of 2H11/2→4I15/2 of Er3+ was observed as high as 3.27 times from 303 to 723 K, which is because of lattice distortion and phonon‐assisted transition. In addition, the optical temperature performance of Sr2.91(PO4)2:.01Er3+/.08Yb3+ sample was studied, and the maximum absolute temperature sensitivity was calculated as.00623 K−1 at 538 K. This study suggests that Sr3(PO4)2:Er3+/Yb3+ phosphors in the presence of impurity Tm3+ have a promising application prospect as optical temperature sensor at high temperature. [ABSTRACT FROM AUTHOR]

Based on the previous optimal concentration of Er3+/Yb3+/Mo4+ co‐doped BiTa7O19 (BTO) samples, Sc3+ or Sb is planned to be doped into BTO:Er3+/Yb3+/Mo4+ for further improving the upconversion luminescence (UCL) intensity under 980‐nm laser excitation. A series of BTO:Er3+/Yb3+/Mo4+/Sc3+ and BTO:Er3+/Yb3+/Mo4+/Sb samples are prepared by high‐temperature solid‐phase sintering method. The microstructure and UCL properties are investigated by X‐ray diffraction, Raman, X‐ray photoelectron spectroscopy (XPS), diffuse reflection, and luminescence spectrum. The green UCL intensity of BTO:Er3+/Yb3+/Mo4+/Sb is little better than that of BTO:Er3+/Yb3+/Mo4+/Sc3+, which reaches 2.40 times than that of β‐NaYF4:Er3+/Yb3+. XPS results show that Sc is 3+, Mo is 4+, and Sb is 3+ and 5+. Raman spectra show that BTO:Er3+/Yb3+/Mo4+/Sb has lower phonon energy and more disorder than BTO:Er3+/Yb3+/Mo4+/Sc3+. The maximum relative temperature sensitivity is got as 0.01012 K−1 at 303 K based on luminescence intensity ratio technology. BTO:Er3+/Yb3+/Mo4+/Sb has outstanding pure green UCL intensity, which can be applied to luminescence display and temperature sensing. [ABSTRACT FROM AUTHOR]

Electrical and thermal transport controlled by growth mode can be used to optimize thermoelectric properties of ZnO:Al films, which was adjusted by the re‐evaporation of Zn and Al via substrate temperatures. The growth modes include equiaxed crystal, columnar crystal and coexistence of both crystals. In the ZnO:Al film, equiaxed crystals improve the carrier mobility and reduce the lattice thermal conductivity. Thus, the carrier mobility and thermal conductivity are tuned by the ratio of equiaxed crystals to columnar crystals. The carrier mobility is dependent on the growth‐mode‐related defects of oxygen vacancies, zinc interstitials and the substitutional dopant of Al. Improved thermoelectric properties with a power factor of 198.45 µW m−1 K−2 at 510 K were achieved. This study presents a film with the structure of an equiaxed‐crystal buffer layer to enhance its thermoelectric properties. [ABSTRACT FROM AUTHOR]

Theory predicts Cu‐doped ZnO (ZnO:Cu) has p‐conductivity; however, this has only been demonstrated in a small number of experimental and mechanistic studies. In this paper, ZnO:Cu films were grown in situ with varying Cu content, prepared using radiofrequency atomic source–assisted molecular‐beam vapor deposition. The results indicate that ZnO:Cu films with dopant of Cu2+ only had n‐type behavior. As the Cu content increased, Cu+ was the major dopant and the ZnO:Cu films had p‐type behavior. However, excess Cu dopant resulted in the formation of second phases of Cu2O and Cu–Zn. The formation of a Cu–Zn phase increased the content of Zn vacancy, thus increasing hole concentration. Stronger alloy scattering decreased carrier mobility. Therefore, Cu+ dopant and Zn vacancy give ZnO:Cu films p‐conductivity properties. [ABSTRACT FROM AUTHOR]

To realize the application of Ni films in magnetic recording media, giant magnetoresistive sensors and microelectromechanical systems, it is necessary to control and improve the magnetic and electrical properties of the films. In this paper, Ni nanocrystalline films with different thicknesses and growth rates are prepared with or without a high magnetic field (HMF). The effects of a HMF on the growth, magnetic and electrical properties of the Ni films are studied. The results show that HMF changes the growth structure of the Ni films from disordered stacked grains to columnar growth along the direction of the HMF. The columnar growth becomes more prominent at a high growth rate and large film thickness. The HMF increases the grain size but decreases the surface roughness of the Ni films. Due to changes in the growth structure, grain size and film quality, the saturation magnetization of the Ni films increase markedly (by 89%), and the resistivity and coercivity significantly decrease (by 89 and 58%, respectively) by the HMF. The remanence ratio of the Ni films is controlled by the HMF. This study shows that a HMF effectively controls the growth and improves the magnetic and electrical properties of Ni films. [ABSTRACT FROM AUTHOR]

Background Laparoscopic hernioplasty is the gold standard treatment for inguinal hernias. Recently, single-incision laparoscopic hernioplasty ( SILH) has been suggested as an alternative technique. It is not evident whether the benefits of this procedure overcome the potential increased risk. Objective The aim of this study was to compare the outcomes of SILH with conventional multi-incision laparoscopic hernioplasty ( MILH) using a meta-analysis of available controlled clinical trials. Methods Eligible articles were identified by searching several databases including Embase, Cochrane, PubMed and Google Scholar databases, up until May 2013. Evaluated outcomes were operative time, post-operative hospital stay, complications, conversion and recurrence. Results Eight controlled clinical trials on 926 patients were randomized to either SILH (495 patients) or MILH (431 patients) for meta-analysis. Overall, there was no significant difference between SILH and MILH in complications, operative time for bilateral inguinal hernia repair, hospital stay, short-term recurrence or conversions. However, the operative time for unilateral inguinal hernia repair was significantly longer for SILH than for MILH (standardized mean difference 0.23 (95% confidence interval: 0.09-0.38); P = 0.00, I2 = 73.6%). Conclusions Our meta-analysis showed that SILH is feasible and safe in certain patients when compared to MILH, and carries a similar outcome, with the exception of longer operative times for unilateral inguinal hernia repair. Additional high-powered randomized trials are needed to determine whether SILH truly offers any advantages; these future studies should focus particularly on failure of technique, pain score, analgesia requirements, cosmesis and quality of life. [ABSTRACT FROM AUTHOR]

A series of Sr2.99‐x(PO4)2:.01Er3+/xYb3+ (x =.02,.04,.06,.08,.10) phosphors in the presence of impurity Tm3+ were synthesized by high temperature solid‐state method, and X‐ray diffraction results show that these samples are pure R‐3 m(166) space group phase. The upconversion luminescence (UCL) of Er3+ and impurity Tm3+ under 980‐nm laser excitation were investigated, and the results show that the intense blue UCL of impurity Tm3+ and thermal enhancement of 2H11/2→4I15/2 of Er3+ simultaneously exist. When Er3+ doping concentration is kept at.01, both the blue UCL intensity of impurity Tm3+ and green and red UCL intensity of Er3+ reach the maximum at Yb3+ doping concentration of.08. The thermal enhancement effect of 2H11/2→4I15/2 of Er3+ was observed as high as 3.27 times from 303 to 723 K, which is because of lattice distortion and phonon‐assisted transition. In addition, the optical temperature performance of Sr2.91(PO4)2:.01Er3+/.08Yb3+ sample was studied, and the maximum absolute temperature sensitivity was calculated as.00623 K−1 at 538 K. This study suggests that Sr3(PO4)2:Er3+/Yb3+ phosphors in the presence of impurity Tm3+ have a promising application prospect as optical temperature sensor at high temperature. [ABSTRACT FROM AUTHOR]