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Sapphire substrates were patterned by a chemical wet etching technique in the micro- and nanoscale to enhance the light output power of InGaN/GaN light-emitting diodes (LEDs). InGaN/GaN LEDs on a pyramidal patterned sapphire substrate in the microscale (MPSS) and pyramidal patterned sapphire substrate in the nanoscale (NPSS) were grown by metalorganic chemical vapor deposition. The characteristics of the LEDs fabricated on the MPSS and NPSS prepared by wet etching were studied and the light output powers of the LEDs fabricated on the MPSS and NPSS increased compared with that of the conventional LEDs fabricated on planar sapphire substrates. In comparison with the planar sapphire substrate, an enhancement in output power of about 29% and 48% is achieved with the MPSS and NPSS at an injection current of 20 mA, respectively. This significant enhancement is attributable to the improvement of the epitaxial quality of GaN-based epilayers and the improvement of the light extraction efficiency by patterned sapphire substrates. Additionally, the NPSS is more effective to enhance the light output power than the MPSS.

In this work, a mixed Langmuir-Blodgett (LB) film was built up using C60 mixed with arachidic acid (AA) and investigated by FT-IR, UV, Raman, and ESR spectroscopies without or with iodine vapor doping at 60 O C for 18-42 h. The positions of peaks in IR and Raman spectra did not change before and after iodine doping. But the positions of electronic absorption in the UV spectra were shifted by ca. 2-4 nm and six hyperfine splitting lines appeared in ESR signals after iodine doping. According to the experimental results, two possible mechanisms for the interaction of Cao with I2 were proposed.

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Objective: To evaluate the usefulness of ultrasonography in assessing laryngeal cancer. Methods: 72 patients with laryngeal carcinoma proven by surgery and pathology were enrolled. The pre-therapeutic ultrasonography and CT images were retrospectively evaluated, including tumour detection, localisation and invasion of intra-and extralaryngeal structures. A comparative assessment was made between the detection rate, correspondence rate of localisation and sensitivity and specificity of ultrasonography and CT. The mobility of the larynx was observed on real-time ultrasonography and compared with laryngoscopy. Results: The detection rate of ultrasonography [63 (87.5%)/72] was lower than that of CT [72 (100.0%)/72] (p50.006). The primary foci were accurately located in 59 (93.7%) of 63 lesions using ultrasonography compared with 70 (97.2%) of 72 lesions using CT (p50.392). In the evaluation of invasion, the sensitivity and specificity of ultrasonography were similar to that of CT in most of the intra-and extralaryngeal structures (p50.059-1.000). A higher specificity was obtained during the assessment of the paraglottic space involvement when using ultrasonography than CT (94.9% vs 66.7%, p50.001). For vocal cord fixation, no statistical difference was found between ultrasonography and laryngoscopy (p50.223). Conclusion: Ultrasonography could be used as a valuable supplementary imaging method to CT and laryngoscopy in the assessment of laryngeal carcinoma, even in male adults with some calcifications of the thyroid cartilage. Advances in knowledge: Our study demonstrates that ultrasonography, which has been used scarcely in the larynx, could supply useful information on the detection, localisation and intra-and extralaryngeal invasion of laryngeal carcinoma.

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Ocean tribology, a new research field of tribology, is currently being established and developed. The tribological behaviors of polyether ether ketone (PEEK), poly(phenyl p-hydroxybenzoate) (PHBA), polyimide (PI), and perfluoroethylene propylene copolymer (FEP) sliding against GCr15 and 316 steel rings under the lubrication of sea water were studied and compared with that under the lubrication of pure water. The results show that the friction and wear behaviors of a polymer under the lubrication of aqueous medium are not only related to the properties of polymer itself, but also to the corrosive effect and lubricating effect of the medium. When a polymer slid against GCr15 steel under sea water lubrication, the friction coefficient and wear rate of polymer were much larger than that under pure water lubrication because of indirect corrosive wear. However, when sliding against corrosionresistant 316 steel, polymers PEEK, FEP, and PI exhibited lower coefficients of friction and wear rates under sea water lubrication, this was attributed to better lubricating effect of sea water as a result of the deposition of CaCO 3 and Mg(OH) 2 on the counterface. On the contrary, the friction coefficient and wear rate of PHBA sliding against 316 steel under sea water lubrication were larger than that under pure water lubrication, which may be related to the properties of PHBA itself.