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排序方式: 共有755条查询结果,搜索用时 46 毫秒
1.
Endoscopic Observation of Tissue by Narrowband Illumination   总被引:6,自引:0,他引:6  
We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.  相似文献
2.
Self-assembled GaSb quantum dots (QDs) with a photoluminescence wavelength longer than 1.3 μm were successfully grown by suppressing the replacement of As and Sb on the surface of the GaSb QDs. This result means that GaSb can thus join InAs or GaInAs as a suitable material for QD lasers for optical communications.  相似文献
3.
Objective assessment of gastrointestinal mucosal color is extremely important in the endoscopic diagnosis of digestive tract disease. In this paper, we propose a method to clarify the spectral characteristics of gastric and colon cancer. A large number of spectral reflectance data of mucous membrane are measured by the endoscopic spectroscopy system (ESS) in the National Cancer Center Hospital East, Kashiwa, Japan and the Department of Internal Medicine, Self-Defense Force Center Hospital, Tokyo, Japan. We assume that early cancer appears primarily in the spectral data of short wavelength, because it is usually present in a superficial cell where short wavelength light is scattered more strongly than long wavelength light. To identify the features in the short wavelength components, the spectral reflectance was divided by the reflectance of a long wavelength. We investigated the possibility of distinguishing early cancer from normal spectral data through statistical analysis, employing the projection axis as the mean difference between them. Early cancer and normal spectral data were projected on the projection axis, and the Student’s T-test was applied to evaluate the mean of the distribution between these data.  相似文献
4.
Our previous report based on a batch reactor system for the Advanced Fenton Process (AFP) showed that pH, hydrogen peroxide and the organic substances treated are among the most important factors affecting the oxidation efficiency. As an extended study towards its potential commercialisation, this paper reports the effects of the main process parameters including those relating to a new laboratory scale AFP flow-through system. In order to systemise and correlate the results, the Taguchi experimental design method was used. Total organic carbon (TOC) removal was utilised as the measure of the oxidation efficiency and it was found that the removal of phenol from aqueous solution at pH 2.0 and 2.5 was very similar but hydrogen peroxide supply significantly affected the TOC removal with the change of flow rate from 14.4 ml/h to 60 ml/h. Also, the initial concentration of phenol was a highly significant factor, with higher concentrations resulting in a lower TOC removal rate. The temperature effects in the range of 14-42 degrees C were investigated and it was found that there was accelerated oxidation of phenol in the early stages but after 90 min there was no significant difference between the results. Sonication with a bath type sonicator resulted in relatively small enhancements of TOC removal but further studies with cup-horn sonication showed that TOC removal increased with higher intensity of sonication.  相似文献
5.
QCD真空凝聚和参数化的夸克传播子   总被引:1,自引:0,他引:1  
基于整体色对称模型,用完全穿衣服参数化的夸克传播子研究了量子色动力学(QCD)真空的性质,预言了各种表征QCD真空的凝聚值。其结果与其他唯象QCD理论模型的预言是一致的。结果清楚地表明了参数化的夸克传播子是成功和可靠的。讨论了计算QCD真空凝聚值时积分截断参数的问题,提出了一个避免计算的结果对截断参数强烈依赖的物理方法。  相似文献
6.
非定域夸克真空的结构和Kisslinger函数   总被引:1,自引:0,他引:1  
夸克的真空凝聚是量子色动力学(QCD)研究中一个非常重要的问题。用完全穿衣服的夸克传播子研究了QCD真空性质和夸克的真空结构。计算了定域夸克的真空凝聚值,预言了夸克的真空结构。其结果与文献中的经验值相符合,也与Dyson-Schwinger方程解一致。说明参数化的夸克传播子是成功和可靠的。  相似文献
7.
Combined convection heat transfer and thermal conduction for film cooling of a flat plate with 45° ribs on one wall was investigated experimentally and numerically. The flat plate surface temperature was measured using thermochromic liquid crystals. The results show that the film cooling is the main mechanism for the local cooling with a very low thermal conductivity while the convection heat transfer of the coolant in the coolant channel is the dominant heat transfer mechanism for the high thermal conductivity plate, with both film cooling and convection heat transfer by the coolant being important with medium thermal conductivity walls.  相似文献
8.
宋志浩  王世荣  肖殷  李祥高 《物理学报》2015,64(3):33301-033301
钙钛矿太阳能电池是一种全新的全固态薄膜电池. 报道的能量转换效率已提高到19.3%, 成为可再生能源领域的热点研究方向. 空穴传输材料是构成高效钙钛矿太阳能电池的重要组分之一. 本文介绍了钙钛矿太阳能电池的基本结构, 对空穴传输材料的分子结构、能级水平和迁移率等对电池性能的影响进行了详细的总结和评述.  相似文献
9.
光纤传递链路中相位噪声探测是基于光纤的精确射频标准传递系统中重要组成部分。为解决光纤链路相位噪声探测中节点反射干扰的问题, 本文基于广义非线性薛定谔方程, 理论上研究了窄带光学频率梳在色散位移光纤中的非线性光学传播特性。在理论分析的基础上, 结合密集波分复用架构, 提出了一种基于锁模光学频率梳进行光纤传递射频信号的相位噪声探测新技术, 克服了节点反射干扰, 给出了初步实验验证。  相似文献
10.
Summary The positron spectrum from the reaction was measured at two distances 37.9 m and 45.9 m from the core of the 2.8 GW power reactor in G?sgen (Switzerland). The data were analysed in terms of two neutrino oscillations of the disappearance type . No evidence for neutrino oscillations was found and limits on the oscillation parameters Δm 2 and sin22θ were derived.
Riassunto Si è misurato lo spettro dei positroni della reazione alle due distanze di 37.9 m e 45.9 dal nucleo del reattore di potenza di G?sgen (Svizzera). Si sono analizzati i dati in termini di due oscillazioni del tipo della sparizione . Non si è trovata alcuna prova di oscillazioni del neutrino e si sono dedotti limiti ai parametri di oscillazione Δm 2 e sin22θ.

Резюме Измерялся спектр позитронов из реакции на двух расстояниях 37.9 м и 45.9 м от активной зоны энергетического реактора в Гэсгене (Щвейцария). Полученные данные анализируются на основе двух нейтринных осцилляций исчезающего типа . Не было обнаружено доказательств для нейтринных осцилляций. Определяются пределы для параметров осцилляций Δm 2 и sin22θ.
  相似文献
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