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光纤光栅传感器波长移位检测方法 被引量:14
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作者 周伟林 刘阳 +2 位作者 杨华勇 李智忠 胡永明 《应用光学》 CAS CSCD 2004年第2期40-43,共4页
光纤光栅波长移位检测是光纤光栅传感器的核心技术之一 ,已提出的光纤光栅波长移位检测方法有被动解调法、匹配光栅法、非平衡 Mach- Zehnder干涉仪法、可调谐窄带光源法和激光锁模法等详细介绍了光纤布拉格光栅(FBG)传感器的波长移位... 光纤光栅波长移位检测是光纤光栅传感器的核心技术之一 ,已提出的光纤光栅波长移位检测方法有被动解调法、匹配光栅法、非平衡 Mach- Zehnder干涉仪法、可调谐窄带光源法和激光锁模法等详细介绍了光纤布拉格光栅(FBG)传感器的波长移位检测方法 ,分析了各种检测方法原理。重点讨论了非平衡 M- Z干涉仪法和可调谐窄带光源法 ,并对以上各种方法的优、缺点进行了分析和讨论。 展开更多
关键词 光纤布拉格光栅 波长移位检测 传感器
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细菌移位检测分别联合螺旋CT小剂量扫描与超声用于急性阑尾炎诊断的临床价值比较 被引量:3
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作者 许军成 祁炳珠 +2 位作者 贾振伟 冯保恒 王欣玲 《临床合理用药杂志》 2015年第31期103-105,共3页
目的比较细菌移位检测分别联合螺旋CT小剂量扫描与超声用于急性阑尾炎诊断的临床价值。方法收集2013年10月-2015年1月来该院就诊的急性阑尾炎疑似病例200例,分别给予细菌移位检测联合螺旋CT小剂量扫描、超声检查及单独螺旋CT小剂量扫描... 目的比较细菌移位检测分别联合螺旋CT小剂量扫描与超声用于急性阑尾炎诊断的临床价值。方法收集2013年10月-2015年1月来该院就诊的急性阑尾炎疑似病例200例,分别给予细菌移位检测联合螺旋CT小剂量扫描、超声检查及单独螺旋CT小剂量扫描和超声检查,比较4项诊断临床价值。结果与单纯螺旋CT小剂量组和超声检查组比较,细菌移位联合螺旋CT小剂量扫描和细菌移位联合超声检查灵敏度、阳性似然比及诊断正确率较高,阴性似然比和诊断错误率较低,差异均有统计学意义(P<0.05);与单独超声检查比较,单独螺旋CT小剂量检查的灵敏度、阳性似然比及诊断正确率较高,阴性似然比及诊断错误率比较,差异亦有统计学意义(P<0.05);而4组间特异度比较差异无统计学意义(P>0.05)。结论联合细菌移位检测可增强急性阑尾炎的CT扫描和超声检查的诊断效果,尤以联合螺旋CT小剂量扫描最为明显。 展开更多
关键词 急性阑尾炎 细菌移位检测 螺旋CT小剂量扫描 超声检查
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细菌移位检测联合螺旋CT小剂量扫描诊断急性阑尾炎的临床观察 被引量:2
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作者 许军成 祁炳珠 +2 位作者 贾振伟 冯保恒 王欣玲 《临床合理用药杂志》 2015年第34期138-139,共2页
目的探讨细菌移位检测联合螺旋CT小剂量扫描诊断急性阑尾炎的临床价值。方法收集2013年10月-2015年1月就诊的疑似急性阑尾炎患者200例,并对所有患者进行细菌移位检测及螺旋CT小剂量扫描,根据诊断标准,比较单独使用螺旋CT小剂量扫描诊断... 目的探讨细菌移位检测联合螺旋CT小剂量扫描诊断急性阑尾炎的临床价值。方法收集2013年10月-2015年1月就诊的疑似急性阑尾炎患者200例,并对所有患者进行细菌移位检测及螺旋CT小剂量扫描,根据诊断标准,比较单独使用螺旋CT小剂量扫描诊断与联合诊断的诊断结果。结果 200例疑似急性阑尾炎患者最终确诊168例,排除32例。细菌移位检测联合螺旋CT小剂量扫描诊断灵敏度、阴性率、阴性似然比和诊断正确率明显高于单独使用螺旋CT小剂量扫描诊断,差异均有统计学意义(P<0.05)。联合诊断阳性率、特异度及阳性似然比虽高于单独使用螺旋CT小剂量扫描诊断,但差异均无统计学意义(P>0.05)。结论细菌移位检测和螺旋CT小剂量扫描联合应用可提高急性阑尾炎诊断的准确率。 展开更多
关键词 急性阑尾炎 细菌移位检测 螺旋CT小剂量扫描 联合诊断
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基于LabVIEW光纤光栅波长移位检测系统
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作者 周伟林 杨华勇 胡永明 《激光与光电子学进展》 CSCD 北大核心 2006年第4期64-67,共4页
LabVIEW是一个高效的图形化程序设计环境,它在测量、测试及工业控制领域已有广泛的应用。介绍了一种基于 LabVIEW的光纤光栅波长移位检测系统,依靠虚拟仪器工作平台(LabVIEW),实现了PC机与可调谐激光器之间的通信及数据采集、分析和显示... LabVIEW是一个高效的图形化程序设计环境,它在测量、测试及工业控制领域已有广泛的应用。介绍了一种基于 LabVIEW的光纤光栅波长移位检测系统,依靠虚拟仪器工作平台(LabVIEW),实现了PC机与可调谐激光器之间的通信及数据采集、分析和显示;从而快速、智能化地实现了光纤光栅波长移位检测。实验表明该系统的波长检测灵敏度为0.00965 nm/℃,波长分辨率为2pm,波长检测范围不受系统限制,一般可达30 nm以上。 展开更多
关键词 LABVIEW 光纤光栅 波长移位检测
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基于时反镜能量检测法的循环移位扩频水声通信 被引量:2
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作者 杜鹏宇 殷敬伟 +1 位作者 周焕玲 郭龙祥 《物理学报》 SCIE EI CAS CSCD 北大核心 2016年第1期213-220,共8页
海面的起伏和多普勒效应使得接收信号的载波相位发生跳变以及水声信道的多途扩展使得接收信号波形发生畸变,这严重影响循环移位扩频系统的性能.本文提出循环移位能量检测器算法,通过检测循环移位匹配滤波器的输出能量对系统进行解码,可... 海面的起伏和多普勒效应使得接收信号的载波相位发生跳变以及水声信道的多途扩展使得接收信号波形发生畸变,这严重影响循环移位扩频系统的性能.本文提出循环移位能量检测器算法,通过检测循环移位匹配滤波器的输出能量对系统进行解码,可有效解决载波相位跳变对循环移位扩频系统的影响;将时间反转镜技术与循环移位能量检测器相结合,进一步提出时反镜能量检测器算法,利用已检测到的符号对信道进行实时估计并进行时反处理,抑制了水声信道多途扩展的影响,保证了循环移位扩频系统可在低信噪比条件下工作.通过大连海上试验以及莲花湖湖上试验验证,在复杂水声信道多途扩展、载波相位跳变和低信噪比条件下实现了低误码水声通信. 展开更多
关键词 水声通信 循环移位扩频 循环移位能量检测 时间反转镜
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穴盘苗温室多末端移栽机运动定位装置设计与试验 被引量:1
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作者 严蕾 毛罕平 +2 位作者 韩绿化 胡建平 王留柱 《农机化研究》 北大核心 2017年第4期83-87,共5页
为了提高穴盘苗温室移栽机械的自动化程度和移栽效率,对温室穴盘苗多末端移栽机运动定位装置进行了设计。基于多末端执行器联合作业的要求,对其分散装置进行力学分析计算,以实现多个末端执行器等间距移动。对系统进行移位检测试验,检测... 为了提高穴盘苗温室移栽机械的自动化程度和移栽效率,对温室穴盘苗多末端移栽机运动定位装置进行了设计。基于多末端执行器联合作业的要求,对其分散装置进行力学分析计算,以实现多个末端执行器等间距移动。对系统进行移位检测试验,检测移栽过程中位置精度,结果表明:128穴盘、4孔花盆自动取苗移位平均值分别为32.291 1、206.324 6mm;通过单样本t检验发现,在0.05显著性水平下,实测取苗移位间隔与设计的穴孔间隔无显著性差异,验证了所设计自动取苗移位装置的可靠性。 展开更多
关键词 温室 自动移栽 运动定位装置 移位检测
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纤维光学 其他
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《中国光学》 EI CAS 2006年第6期47-48,共2页
TN25 2006065218单模石英光纤和塑料光纤自动耦合系统=Auto-coupling system for single-mode silica optical fiber with polymer op- tical fiber[刊,中]/陈松涛(浙江大学信息与电子工程学系.浙江,杭州(310027)),杨冬晓…//半导体光... TN25 2006065218单模石英光纤和塑料光纤自动耦合系统=Auto-coupling system for single-mode silica optical fiber with polymer op- tical fiber[刊,中]/陈松涛(浙江大学信息与电子工程学系.浙江,杭州(310027)),杨冬晓…//半导体光电,—2006.27(3).——282-285研制了一种可实现单模塑料光纤和单模石英光纤之间的自动连接(耦合)系统。该系统通过上位机控制部分对光功率计和采集图像的反馈数据进行分析处理,进而驱动高精度位移步进电机,使两光纤达到精确耦合,从而为单模塑料光纤和塑料光纤光栅的进一步研究打下了坚实的基础。图6参11(严寒) 展开更多
关键词 塑料光纤光栅 保偏光纤 单模石英光纤 波长移位检测 超辐射发光二极管 微透镜 纤维光学 半导体 系统 藕合
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数显装置改造东德BL2411—65座标镗床
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作者 朱永明 《电子工艺简讯》 1995年第5期19-20,共2页
采用数显装置改造老设备和提高普通设备的精度,具有投资少,精度高,周期短,见效快的特点,这项技术在改造库、钳、铣、磨、镗、测量等旧设备中广泛运用,本文主要论述利用这项技术,改造我厂一台已报废的进口座标镗床取得了成功。
关键词 数显装置 精密移位检测 座标镗床 改造
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磁光记录技术的近期发展
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作者 岳云 《今日电子》 2002年第12期50-51,54,共3页
关键词 磁光记录技术 记录密度 磁致超解像技术 磁畴壁移位检测 磁畴放大再生技术 近场光学技术
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Damage alarming for bridge expansion joints using novelty detection technique based on long-term monitoring data 被引量:4
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作者 缪长青 邓扬 +1 位作者 丁幼亮 李爱群 《Journal of Central South University》 SCIE EI CAS 2013年第1期226-235,共10页
Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for... Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for bridge expansion joints based on long-term monitoring data was developed. The effects of environmental factors on the expansion joint displacement were analyzed. Multiple linear regression models were obtained to describe the correlation between displacements and the dominant environmental factors. The damage alarming index was defined based on the multiple regression models. At last, the X-bar control chart was utilized to detect the abnormal change of the displacements. Analysis results reveal that temperature and traffic condition are the dominant environmental factors to influence the displacement. When the confidence level of X-bar control chart is set to be 0.003, the false-positive indications of damage can be avoided. The damage sensitivity analysis shows that the proper X-bar control chart can detect 0.1 cm damage-induced change of the expansion joint displacement. It is reasonably believed that the proposed technique is robust against false-positive indication of damage and suitable to alarm the possible future damage of the expansion joints. 展开更多
关键词 damage alarming expansion joint TEMPERATURE traffic condition control chart suspension bridge
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A Group-Based Fingerprinting Scheme for Digital Wholesale and Retail 被引量:1
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作者 ZHAO Yong ZHANG Aixin LU Songnian 《China Communications》 SCIE CSCD 2014年第10期126-135,共10页
Prior group-based fingerprinting achieves better detection performance when colluders are from the same group. But in digital wholesale and needs to be identified retail, the middleman as well as customers especially ... Prior group-based fingerprinting achieves better detection performance when colluders are from the same group. But in digital wholesale and needs to be identified retail, the middleman as well as customers especially against group colluding attack. The group tracing is neglected in previous works. In this paper, we propose a novel multimedia group fingerprint to trace malicious middlemen along with customers. We explore the quality of the non degenerate linear shift register sequence (NDLSRS) which is convenient in group initialization and management. The theoretic analysis and simulation experiment results show that NDLSRS has good resistance against attacks from colluding groups/ members even after its volume expanded. 展开更多
关键词 Group fingerprint non-degeneratelinear shift register sequence wholesale andretail group colluding attack
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Development of a Seismometer-Type Absolute Displacement Sensor Aimed at Detecting Earthquake Waves with a Large Magnitude and Long Period
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作者 Kazuto Seto Yuichi Iwasaki +1 位作者 Akihiko Itoh Ikuo Shimoda 《Journal of Civil Engineering and Architecture》 2012年第6期721-729,共9页
This paper proposes a novel seismometer-type absolute displacement sensor aimed at detecting earthquake waves with a large magnitude and long period. However, since the measuring range of the displacement sensor is hi... This paper proposes a novel seismometer-type absolute displacement sensor aimed at detecting earthquake waves with a large magnitude and long period. However, since the measuring range of the displacement sensor is higher than its natural frequency, it is difficult to detect low frequency vibrations below 1 Hz using a conventional a seismic-type displacement sensor. In order to provide an absolute displacement detection which is capable of lowering the natural frequency and enlarging the detectable amplitude without causing structural defects, the relative signals of displacement, velocity, and acceleration between a detected object and the auxiliary mass of the sensor are fed back into the sensor. In addition, phase lag compensation is inserted to adjust phase angles, which are of a frequency of 1 Hz. According to simulation results, a detection range from 0.1 Hz to 50 Hz is expected. It has been demonstrated that the developed sensor with a small size and light weight has a detection range of from 0.5 Hz to 50 Hz for absolute displacement and velocity. As an additional advantage, the measurement displacement amplitude has been expanded to about 20 dB. This sensor is available to use for the active control method. of flexible structures like high rise buildings using the LQ control 展开更多
关键词 VIBRATION displacement sensor earthquake wave MEASUREMENT structural control.
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Multiple phase detector of M-ary phase shift keying symbols in code division multiple access systems 被引量:1
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作者 QUAN Zhi 《Journal of Central South University》 SCIE EI CAS 2011年第4期1080-1086,共7页
A novel iterative technique, the phase descent search detection was proposed. This technique constrained the solution (PDS) algorithm, for M-ary phase shift keying (M-PSK) symbols to have a unit magnitude and it w... A novel iterative technique, the phase descent search detection was proposed. This technique constrained the solution (PDS) algorithm, for M-ary phase shift keying (M-PSK) symbols to have a unit magnitude and it was based on coordinate descent iterations where coordinates were the unknown symbol phases. The PDS algorithm, together with a descent local search (also implemented as a version of the PDS algorithm), was used multiple times with different initializations in a proposed multiple phase detector; the solution with the minimum cost was then chosen as the final solution. The simulation results show that for highly loaded multiuser scenarios, the proposed technique has a detection performance that is close to the single-user bound. The results also show that the multiple phase detector allows detection in highly overloaded scenarios and it exhibits near-far resistance. In particular, the detector has a performance that is significantly better, and complexity that is significantly lower, than that of the detector based on semi-definite relaxation. 展开更多
关键词 coordinate descent COMPLEXITY M-ary phase shift keying (M-PSK) multiuser detection quadratic optimization semi-definite relaxation
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Establishment of orthotopic transplantation model of human bladder cancer and detection by MRI
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作者 Shenmin Yang Duangai Wen +2 位作者 Jianquan Hou Jun He Jianhua Chen 《The Chinese-German Journal of Clinical Oncology》 CAS 2008年第1期51-54,共4页
Objective: To establish an orthotopic bladder cancer model bearing human bladder cancer for experimental research, and monitor tumor progression by magnetic resonance imaging (MRI). Methods: The mucosa was mechanicall... Objective: To establish an orthotopic bladder cancer model bearing human bladder cancer for experimental research, and monitor tumor progression by magnetic resonance imaging (MRI). Methods: The mucosa was mechanically damaged transurethrally under direct vision, and then human bladder cancer cell line T24 was inoculated into the bladders of BALB/c nude mice to establish orthotopic bladder cancer model. To find a suitable concentration of Gd-DTPA for this re- search. MRI was performed weekly to assess tumor growth, using Gd-DTPA as contrast agent. The pathologic morphology of the bladders and other specimens were observed with HE stain. Results: All the 25 mice developed bladder cancer after inoculation. The best concentration of Gd-DTPA was 1.408 mg/mL. On MRI, no change in the bladders was observed on day 7 after inoculation, filling defect in the bladders, accordant to actual tumor size, was detected on days 14, 21 and 28. Pathologic examination showed that tumor grew in the mucosa or superficial muscle of bladder on day 7, confined in muscle layer on days 14–28, and invaded serosa on day 35. Conclusion: Transurethrally damaged bladder mucosa under direct vision and instilled bladder cancer cell T24, we successfully established an orthotopic bladder cancer model. Tumor growth simulated the progression of human bladder cancer approximately. MRI was a reliable way for dynamic detection of murine orthotopic bladder tumor. 展开更多
关键词 bladder neoplasms animal model magnetic resonance imaging (MRI)
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