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Search Results: 1 - 10 of 257153 matches for " 李炳乾 "
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A New Type High Power Lighting Emitting Diodes Based on MCPCB and its Opto-electrical Characteristics
基于金属线路板的新型大功率LED及其光电特性研究

Li Bingqian,

光子学报 , 2005,
Abstract: A new type of high power white LEDs (HPW-LEDs) based on metal core printed circuit board (MCPCB) and chip on board (COB) technique is designed and demonstrated, its opto-electrical characteristics are measured. The saturated characteristics of luminous flux is obvious at the forward current 800 mA (corresponding the forward power 3.3 mW), and the saturated characteristics of voltage-current is obvious until the forward current added to 800 mA, (corresponding the forward power 3.3 mW). These results show the MCPCB and COB technique could solve the problem of heat transfers very well, so the HPW-LEDs could work at a high level forward power. At the same time, the spectrum, luminous flux, and chromaticity coordinates of HPW-LEDs change with forward current are studied.
双氢杨梅素与G-四链体的相互作用研究
蒋才武,,
化学学报 , 2007,
Abstract: 双氢杨梅素(DMY)是从药用植物——广西藤茶中提取出来的一种含量极高的二氢黄酮醇类化合物,具有抗肿瘤、抗氧化、调节血糖等作用,但其抗肿瘤机理尚不清楚.本文利用Tm值和CD光谱对G-四链体进行了表征,利用电子吸收光谱和竞争性结合实验研究了DMY与G-四链体的相互作用.结果显示DMY是通过外部堆积结合到G-四链体,并通过稳定G-四链体结构而抑制端粒酶活性,起到抗肿瘤的作用.
固定义齿联合活动义齿修复牙本质发育不全患者1例
A treatment approach combining fixed and removable partial dentures: a clinical report for dentinogenesis imperfect

索来,陈志强,罗锋,中杰,
- , 2015, DOI: 10.7518/gjkq.2015.03.003
Abstract: 摘要:
牙本质发育不全(DI)是一种遗传性疾病,患者牙本质发生病变,尤其多发于恒牙。患牙临床表现为棕黄色、釉质缺失、过度磨耗等,修复治疗这类牙具有极高的挑战性。本文报道1例用固定义齿联合活动义齿修复牙本质发育不全的患者。
Abstract:
中图分类号
基于滑模观测器的无人推力矢量飞机反步容错控制
Backstepping Fault-Tolerant Control for Unmanned Thrust-Vectoring Aircraft Based on Sliding-Mode Observer

,董文瀚,马小山
- , 2018,
Abstract: 针对无人推力矢量飞机,设计了基于滑模观测器的反步容错控制。首先提出执行器故障模型,并将本体方程分为快、慢回路,建立包含不确定性、舵面故障和执行器故障的无人推力矢量飞机故障模型,然后设计包含高阶滑模观测器及不连续投影自适应律的级联观测器实现补偿不确定性和舵面故障的状态估计,并通过滑模观测器实现故障辨识和故障参数估计,最后结合状态估计及故障参数实现包容不确定性,舵面故障和执行器故障的全局反步容错控制。大迎角机动仿真表明所提方法能够有效实现无人推力矢量飞机的全局容错控制。
In this paper, a backstepping fault-tolerant control based on sliding-mode observer is proposed for the unmanned thrust-vectoring aircraft (UTVA) control. First, the UTVA model with the uncertainty, control surface damage and actuator faults is described, which is divided into fast loop and slow loop. Next, the cascade observers including a high-order SMO and the discontinuous projection adaptive law are proposed to estimate the states with compensating the uncertainty and control surface damage, and the sliding-mode observer is designed to identify actuator faults and estimate fault parameters. Then, the backstepping fault-tolerant control combining the estimation of states and fault parameters is proposed to achieve the global fault-tolerant control, which compensates the uncertainty, control surface damage and actuator faults. Finally, simulation results are given to demonstrate the effectiveness for UTVA
Self-adaptive Contrast Enhancement Algorithm for Infrared Images Based on Plateau Histogram
基于平台直方图的红外图像自适应增强算法

,刘上,周慧鑫,
光子学报 , 2005,
Abstract: In this paper, a new self adaptive contrast enhancement algorithm for infrared images is presented based on plateau histogram equalization. By self adaptively selecting threshold value, this algorithm can enhance objects efficiently , and constrain the background and noises greatly in infrared images. With the proposed method, the disadvantages of histogram equalization are overcome, and large computational amount decreased greatly compared to other plateau histogram equalization algorithm while achieving high contrast. Theory analysis and experiments show that it is an effective enhancement algorithm for infared images.
OPTICAL CHARACTERISTICS AND OPTIMUM DESIGN OF OPTRICAL EXICITED SELF-RESONANT POLYSILICON SENSOR
光激光拾自谐振传感器的光学特性及优化设计

Li Bingqian,Zhu Changchun,Liu Junhua,
,朱长纯,刘君华

光子学报 , 2002,
Abstract: Multilayer model is established for self-resonant polysilicon sensor.Then,the optical characteristics of the sensor are analyse by this model in theoretical,and the thickness of the microbeam and the high of the cavity is optimized.
基于时序SAR技术的采空区上方高速公路变形监测及预测方法
范洪冬,邓喀中,祝传广,,培现
煤炭学报 , 2012,
Abstract: 为掌握采空区上方所建高速公路的变形趋势,解决老采空区上方地表变形监测数据较少,不易建立时序沉降预测模型的问题,利用D-InSAR(DifferentialInterferometricSyntheticApertureRadar)技术对某高速公路进行了变形监测和分析,同时将其结果同地面实测数据相融合,并以LS-SVM(LeastSquares-SupportVectorMachine)为基础,建立了采空区上方高速公路变形预计模型,通过实例,验证了模型的正确性。具体过程:处理融合数据为等时间间隔,并将其趋势项去除,对余项进行平稳性、正态性及零均值处理;利用Cao方法计算嵌入维数,建立训练样本集,并进行LS-SVM学习训练;最后,采用训练好的模型对未来地表沉降进行预计。以511号监测点为研究对象,建立滚动预计方法,结果显示其最大下沉绝对误差3mm,最大相对误差2.2%,取得了较为可靠的预计成果。
海水工厂化养殖废水循环利用的初步探讨
林更铭,,项鹏,杨清良
海洋科学 , 2009,
Abstract: 以海水工厂化养殖排出的废水养殖双齿围沙蚕(Perinereisaibuhitensis)、菲律宾蛤仔(Ruditapesphilippinarum)、长牡蛎(Crassostreagigas)和细基江蓠(Gracilariatenuistipitata)。结果表明:双齿围沙蚕耐污染能力最强;细基江蓠和双齿围沙蚕具有较强的净化水质能力。养殖废水经7d处理后,NH4+-N、NO3
东昆仑埃坑德勒斯特二长花岗岩锆石U-Pb定年及地质意义
杨延,碧乐,许庆林,
西北地质 , 2013,
Abstract: 埃坑德勒斯特是近年来在东昆仑地区发现的首例典型的斑岩型钼 (铜)矿,其矿床与区域地质研究程度很低。矿床产于东昆南复合拼接带,容矿围岩为闪长岩、二长花岗岩、花岗斑岩、中细粒花岗岩及洪水川组火山-沉积岩。笔者重点对主要容矿围岩二长花岗岩进行了LA-ICP-MS锆石U-Pb测年。花岗岩中锆石呈自形-半自形,发育典型的岩浆锆石振荡生长环带,Th/U值较高 (0.83~1.47,平均为1.15),为典型的岩浆锆石。测得二长花岗岩U-Pb加权平均年龄为 (268.7±1.6)Ma,MSWD=0.24;谐和年龄值为 (268.5±0.83)Ma,MSWD=0.051,属晚华力西期,较前人认为的晚印支期早。综合分析认为,268 Ma±区内已经进入大洋俯冲阶段。
洗必泰消毒印模材料抑菌效果的观察
王剑万,肖晓蓉,蒋丽东方
华西口腔医学杂志 , 2006,
Abstract:
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