We report on the design and fabrication of a dual-wavelength switchable quantum cascade laser (QCL) by optimizing homogeneous active region combining superposed distributed feedback gratings. Coaxial, single-mode emissions at two different wavelengths were achieved only through adjusting bias voltage. Room temperature continuous-wave operation with output powers above 30 mW 75 was realized for ...

background: according to previous studies there are some different opinions on the pre-emptive effects of paracetamol in controlling post-operative pain, we aimed to compare the analgesic effects of pre-emptive paracetamol with post-operative paracetamol and morphine in patients undergoing septorhinoplasty. materials and methods: a hundred and six patients aged 15 to 50 were divided into 3 grou...

we conducted this study to determine the risk of transmission of q fever to health care workers (hcws) during perioperative exposure to coxiella burnetii -infected thoracic endovascular aneurysm stent graft. pre-operative and 6-week post-operative phase i and ii igg q fever antibody titers were determined in 14 staff members of an operation room. the room had a negative pressure and all the mem...

Lhasa is a “solar city” with high altitude, located in a cold zone in China. Due to the lack of mineral energy sources and the fragility of its ecological environment, solar heating technology is the first choice to satisfy the demand of indoor thermal comfort for building heating. In this study, an accurate solar heating system in Lhasa was investigated under the simultaneous charging and disc...