期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
光放大法在物理实验教学中的应用与思考
1
作者 张政 《广西物理》 2024年第2期102-105,共4页
2022年全国甲卷理综第25题以光点式检流计为情景,考察了光放大法在物理情景中的应用。光放大法又叫光杠杆放大法,通常运用光沿直线传播的原理将实验中微小的物理量加以放大,使实验效果更加明显。通过放大思想增强微小实验现象的直观性... 2022年全国甲卷理综第25题以光点式检流计为情景,考察了光放大法在物理情景中的应用。光放大法又叫光杠杆放大法,通常运用光沿直线传播的原理将实验中微小的物理量加以放大,使实验效果更加明显。通过放大思想增强微小实验现象的直观性和可视性,方便测量实验数据,分析得出实验结论,本文通过回顾微小形变实验、扭秤实验、光点式检流计原理以及玻璃杯固有频率的测量实验分析光放大法在物理教学中的应用。 展开更多
关键词 光放大法 实验 直观性
原文传递
念力转机运动原理的研究
2
作者 张雷明 寻之朋 +1 位作者 张伟 宋宁 《大学物理》 2019年第4期13-17,27,共6页
对念力转机的运动原理进行了理论分析和实验研究.理论上基于念力转机的力学原理,分析它的转动原理,研究其转动特性.理论分析表明念力转机前端铁钉做周期性类椭圆运动,木棍和铁钉的振动带动螺旋桨转动,螺旋桨的转动方向取决于水平振动和... 对念力转机的运动原理进行了理论分析和实验研究.理论上基于念力转机的力学原理,分析它的转动原理,研究其转动特性.理论分析表明念力转机前端铁钉做周期性类椭圆运动,木棍和铁钉的振动带动螺旋桨转动,螺旋桨的转动方向取决于水平振动和竖直振动的相位差.实验上采用光放大法观察念力转机的运动过程,实验结果和理论分析结果吻合.实验表明用手施加水平力时,螺旋桨的旋转方向与手的触碰位置有关.实验还发现单位时间摩擦凹槽的数目越多,螺旋桨转速越大,两者具有线性关系. 展开更多
关键词 念力转机 力学原理 转动特性 光放大法
下载PDF
Diagnosis of gastric intraepithelial neoplasia by narrow-band imaging and confocal laser endomicroscopy 被引量:11
3
作者 Shu-Fang Wang Yun-Sheng Yang +7 位作者 Li-Xin Wei Zhong-Sheng Lu Ming-Zhou Guo Jin Huang Li-Hua Peng Gang Sun En-Qiang Ling-Hu Jiang-Yun Meng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第34期4771-4780,共10页
AIM:To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnifica-tion endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE). METHODS:... AIM:To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnifica-tion endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE). METHODS:Eligible patients with suspected gastric IN lesions previously diagnosed by endoscopy in secondary hospitals and scheduled for further diagnosis and tratment were recruited for this study. Excluded from the study were patients who had liver cirrhosis, impaired renal function, acute gastrointestinal (GI) bleeding, coagulopathy, esophageal varices, jaundice, and GI post-surgery. Also excluded were those who were pregnant, breastfeeding, were younger than 18 years old, or were unable to provide informed consent. All patients had all mucus and bile cleared from their stom-achs. They then received upper GI endoscopy. When a mucosal lesion is found during observation with whitelight imaging, the lesion is visualized using maximal magnification, employing gradual movement of the tip of the endoscope to bring the image into focus. Saved images are analyzed. Confocal images were evaluated by two endoscopists (Huang J and Li MY), who were familiar with CLE, blinded to the related information about the lesions, and asked to classify each lesion as either a low grade dysplasia (LGD) or high grade dysplasia (HGD) according to given criteria. The results were compared with the final histopathologic diagnosis. ME-NBI images were evaluated by two endoscopists (Lu ZS and Ling-Hu EQ) who were familiar with NBI, blinded to the related information about the lesions and CLE images, and were asked to classify each lesion as a LGD or HGD according to the "microvascular pattern and surface pattern" classification system. The results were compared with the final histopathologic diagnosis. RESULTS: The study included 32 pathology-proven low grade gastric IN and 26 pathology-proven high grade gastric IN that were detected with any of the modalities. CLE and ME-NBI enabled clear visualization of the vascular microsurface patterns and microvascular structures of the gastric mucosa. The accuracy of the CLE and the ME-NBI diagnosis was 88% (95% CI:78%-98%) and 81% (95% CI: 69%-93%), respectively. The kappa coefficient of agreement between the histopathology and the in vivo CLE imaging was 0.755; between the histopathology and the in vivo CLE imaging was 0.615. McNemar's test (binomial distribution used) indicated that the agreement was significant (P < 0.05). When patients were diagnosed by MENBI with CLE, the overall accuracy of the diagnosis was 86.21% (95% CI:73%-96%), and the kappa coefficient of agreement was 0.713, according to McNemar's test (P < 0.05). CONCLUSION:Higher diagnostic accuracy, sensitivityand specificity of CLE over ME-NBI indicate the feasibility of these two techniques for the efficacious diagnostic classification of gastric IN. 展开更多
关键词 Gastric intraepithelial neoplasia Histologicaldiagnosis Confocal laser endomicroscopy Magnifica-tion endoscopy Narrow-band imaging Gastric intraepi-thelial neoplasia lesion
下载PDF
Dynamic Subcarrier Assignment for OFDM-PON Network Based on RSOA for ACCORDANCE 被引量:2
4
作者 LIU Zhuo ZHANG Min +2 位作者 JIANG Jun ZHAN Yueying CHEN Xue 《China Communications》 SCIE CSCD 2014年第6期81-88,共8页
In this paper, we overview the principle of Orthogonal Frequency Division Multiplexing Passive Optical Network (OFDM-PON) systems, with a particular focus on upstream architectures capable of achieving 10Gbit/s colo... In this paper, we overview the principle of Orthogonal Frequency Division Multiplexing Passive Optical Network (OFDM-PON) systems, with a particular focus on upstream architectures capable of achieving 10Gbit/s colorless upstream transmission using Reflective Semiconductor Optical Amplifier (RSOA). We propose an architecture of RSOA based OFDM-PON which can achieve 10Gbit/s upstream transmission over a single wavelength. A novel Dynamic Subcarrier Assignment (DSA) algorithm is also proposed to support my architecture, namely Service based Polling in Pipeline (SPP) dynamic subcarrier algorithm. A simulation was conducted to study the performance of SPP algorithm. Compared with the traditional dynamic bandwidth allocation algorithms, service based polling meets the quality of in pipeline algorithm service requirements excellently, and adapts orthogonal frequency division multiplexing passive optical network better with higher bandwidth efficiency and lower algorithm complexity. 展开更多
关键词 OFDM-PON RSOA DBA QoS SPP
下载PDF
Immunomagnetic assay combined with CdSe/ZnS amplification of chemiluminescence for the detection of abscisic acid 被引量:4
5
作者 ZHOU GuoHua, WANG Ping, YUAN Ju, QIU Ting & HE ZhiKe Key Laboratory of Analytical Chemistry for Biology and Medicine, Ministry of Education College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China 《Science China Chemistry》 SCIE EI CAS 2011年第8期1298-1303,共6页
Abscisic acid (ABA) is an important plant hormone. It plays a key role in regulating plant responses to abiotic stress and in controlling seed germination, growth, and stomatal aperture. A rapid, sensitive analytical ... Abscisic acid (ABA) is an important plant hormone. It plays a key role in regulating plant responses to abiotic stress and in controlling seed germination, growth, and stomatal aperture. A rapid, sensitive analytical method for the ABA detection is urgently required for further investigation of ABA signaling. In this work, an immunomagnetic assay combined with CdSe/ZnS amplification of chemiluminescence has been developed for the detection of ABA. The result could be read out in 30 min at least, with the simplified procedure of immunomagnetic assay. Under the optimized condition, a linear range from 1 pM to 10 nM was obtained. An unexpected result induced by the dose hook effect was discussed. This method provided the high selectivity for ABA over other components that might be contained in real samples. 展开更多
关键词 abscisic acid immunomagnetic assay CHEMILUMINESCENCE CDSE/ZNS
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部