Photoluminescence of Multilayer InAs Quantum Dots

采用MBE设备生长了多层InAs/GaAs量子点结构,测量了其变温光致发光谱和时间分辨光致发光谱。结果表明多层量子点结构有利于减小发光峰的半高宽,并且可以提高发光峰半高宽和发光寿命的温度稳定性。实验发现,加InGaAs盖层后,量子点发光峰的半高宽进一步减小,最小达到23.6 meV,并且发光峰出现红移。原因可能在于InGaAs盖层减小了InAs岛所受的应力,阻止了In组分的偏析,提高了InAs量子点尺寸分布的均匀性和质量,导致载流子在不同量子点中的迁移效应减弱。Multilayer InAs/GaAs quantum dots structures were grown by molecular-beam epitaxy(MBE).The steady-state and time-resolved photoluminescence of the samples were measured at various temperatures.Results showed that multilayer structures could not only narrow the photoluminescence FWHM(full width at the half maximum) but enhance the stability of the photoluminescence lifetime and FWHM.As for the quantum dots with InGaAs cap layer,the photoluminescent spectra became narrower(the narrowest FWHM was only 23.6meV) and the photoluminescent wavelength became longer.The possible reason for the above phenomena was that the InGaAs cap layer could both release the strains in InAs islands and inhibit segregation of In components,resulting in the weaker migration among different quantum dots

各種の藍に含まれる不純物赤色色素の検出

In the previous paper we reported the presence of a red colorant contained only in sukumo, Japanese natural indigo dye produced from Polygonum tinctorium, and another red colorant contained only in synthetic indigo and the discrimination between natural indigo dyeing and synthetic indigo dyeing by the analysis of these red colorants. Herein, we report that the former red colorant is present in sukumo of various origin, sukumo derived from Strobilanthes cusia and woad and that the discrimination can also be applicable for indigo dyed silk

MIDCAB の Pitfall

金沢大学医薬保健研究域医学系Six thoroughly selected patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB). While monitoring left ventricular function with transesophageal echocardiography, MIDCAB was done by performing small left thoracotomy through the fourth intercostal space, dissection of the left internal thoracic artery without thoracoscopy, ischemic preconditioning, and grafting of the internal thoracic artery to the left anterior descending coronary artery with 8-0 polypropylene continuous suture. A home-made cardiac stabilizer and Visuflow enabled us to perform precise suturing of the internal thoracic artery. The patency of all grafts was confirmed by early transthoracic Doppler echocardiography and selective angiography. A new stenosis of the coronary artery distal to the anastomosis was detected probably due to coronary snaring in one patient. The anastomosis sites were confined to the distal segments of the left anterior descending coronary artery in MIDCAB patients. The optimal anastomosis site may be missed in the patients with proximal left anterior descending artery disease. An experimental study of myocardial tissue oxygen saturation using near infrared spectroscopy showed that two times of coronary occlusion and reperfusion provided satisfactory effects of ischemic preconditioning. Measurement of the myocardial tissue oxygen saturation may be helpful for confirming effective ischemic preconditioning and a safe coronary occlusion during MIDCAB. Although MIDCAB is an attractive procedure, we should consider the accuracy of anastomosis, the risk of possible incomplete revascularization, the indications, and long-term results

肝切除の看護を経験して

Article信州大学医学部附属病院看護研究集録 1984: 1-7 (1984)departmental bulletin pape