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视网膜色素变性光传递过程中相关基因研究
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作者 马晓晔 魏锐利 朱莉 《眼科研究》 CSCD 北大核心 2001年第3期280-282,共3页
通过对视网膜色素变性的致病基因的分子遗传学分析,目前认为视杆细胞中存在针对光电转换酶促级联体系的反馈系统,当这一体系中相关基因发生突变时,反馈系统持续激活锥体代偿功能系统和杆体更新系统,导致代谢紊乱,进而导致感光细胞... 通过对视网膜色素变性的致病基因的分子遗传学分析,目前认为视杆细胞中存在针对光电转换酶促级联体系的反馈系统,当这一体系中相关基因发生突变时,反馈系统持续激活锥体代偿功能系统和杆体更新系统,导致代谢紊乱,进而导致感光细胞的程序性死亡。本文就光传递过程中相关基因的功能分析,为视网膜色素变性致病机制的研究提供基础。 展开更多
关键词 相关基因 光传递 细胞程序性死亡
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光学三维扫描仪光强传递函数的测量和校正 被引量:12
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作者 张旭 邵双运 +1 位作者 祝祥 宋志军 《中国光学》 EI CAS CSCD 北大核心 2018年第1期123-131,共9页
由于数字光栅投影仪的光强传递函数对于正弦投影条纹的质量以及相位测量精度起着至关重要的作用,本文提出了一种校正光学三维扫描仪光强传递函数的新方法。首先,分析了由于投影仪非线性响应引起的光栅谐波的相位测量误差;然后,通过投影... 由于数字光栅投影仪的光强传递函数对于正弦投影条纹的质量以及相位测量精度起着至关重要的作用,本文提出了一种校正光学三维扫描仪光强传递函数的新方法。首先,分析了由于投影仪非线性响应引起的光栅谐波的相位测量误差;然后,通过投影一组不同灰度级的图像,并利用光功率计测出数字投影仪投出图像的亮度。接着,通过分析得到数字投影仪的非线性响应特性曲线,再经过数据处理,即可获得投影仪的光强传递函数;最后,对光强传递函数进行反函数逆变换,得到一个校正后的非正弦光栅,利用投影仪对该光栅的投影即可在被测物体表面上获得一个正弦光栅。数字投影仪对标准平板的测量结果表明,校正前平均误差为0.71 mm,校正后为0.55 mm;对于标准量块的测量,校正前的平均误差为0.62 mm,校正后为0.15 mm。上述结果表明,本文提出的方法可以减小由于系统非线性响应引起的测量误差并提高测量精度。 展开更多
关键词 相位测量 传递函数 非线性 校正
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城域光传送网光缆组网方案研究 被引量:1
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作者 贾明 郭薇 《电信快报(网络与通信)》 2007年第3期41-43,共3页
经过近几年的建设,各运营商的城域光传送网已初具规模,但是随着网络的发展和整个通信环境的变化、越来越多的数据和多媒体等新业务的涌现以及3G业务的即将开通,对目前的城域光传送网提出了新的要求,因此,在建设的同时对现网进行优化势... 经过近几年的建设,各运营商的城域光传送网已初具规模,但是随着网络的发展和整个通信环境的变化、越来越多的数据和多媒体等新业务的涌现以及3G业务的即将开通,对目前的城域光传送网提出了新的要求,因此,在建设的同时对现网进行优化势在必行。文章从现状分析入手,结合不同情况对城域光传送网光缆组网方案进行研究。 展开更多
关键词 城域光传递 分层结构 缆组网
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光合电子传递及其改善 被引量:1
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作者 米华玲 朱新广 《生命科学》 CSCD 2024年第9期1168-1174,共7页
光合电子传递是继光能化学反应之后的光反应过程,包括线性电子传递和围绕光系统Ⅰ的环式电子传递两种类型。线性电子传递产生ATP和NADPH,用于光合碳同化;而环式电子传递只产生ATP,没有NADPH的形成。在原核光合生物蓝藻中,还有光合电子... 光合电子传递是继光能化学反应之后的光反应过程,包括线性电子传递和围绕光系统Ⅰ的环式电子传递两种类型。线性电子传递产生ATP和NADPH,用于光合碳同化;而环式电子传递只产生ATP,没有NADPH的形成。在原核光合生物蓝藻中,还有光合电子传递的电子共用电子载体的交替电子传递途径。在正常条件下,线性电子传递为主要途径,环式电子传递占的比例很小;但在特殊时期,如稻麦灌浆期以及变动的环境条件下,环式电子传递会被诱导,从而发挥光破坏防御作用。本文综述光合电子传递的相关研究,并分析其遗传改造的可行性。 展开更多
关键词 合电子传递 线性电子传递 围绕系统Ⅰ的环式电子传递 CO_(2)吸收 破坏防御
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PMP测量系统中正弦光栅的优化设计 被引量:1
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作者 段广辉 曹益平 《工具技术》 北大核心 2016年第6期94-99,共6页
提出一种基于光强传递函数(ITF)正弦光栅的优化设计方法,并应用于相位测量轮廓术(PMP)系统进行复杂三维面形测量。PMP测量系统由光栅投影和变形条纹的信息采集系统组成。由于信息采集受到DLP、CCD以及环境等诸多因素的影响,整个系统的... 提出一种基于光强传递函数(ITF)正弦光栅的优化设计方法,并应用于相位测量轮廓术(PMP)系统进行复杂三维面形测量。PMP测量系统由光栅投影和变形条纹的信息采集系统组成。由于信息采集受到DLP、CCD以及环境等诸多因素的影响,整个系统的光强传递函数是非线性的。通过对该系统的光强传递函数的测量,可以看到其函数图像整体上为非线性,而局部的连续区间是线性关系。传统正弦光栅一般采取条纹对比度最大且灰度值范围最大化的设计方法,该设计在信息采集时存在非线性,影响PMP的测量精度。如果设计的正弦光栅的峰值和谷值正好落在传递函数线性区间的上限和下限,会提高PMP的测量精度;当峰值和谷值落在线性区间而对比度较低时,则会影响测量精度。因此,灰度值落在线性区且对比度最大化时的正弦光栅正是优化的最佳目标。实验验证了该方法的有效性。 展开更多
关键词 三维测量 相位测量轮廓术 传递函数 对比度
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相位恢复算法研究进展 被引量:2
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作者 张宇 张洪文 远国勤 《激光与红外》 CAS CSCD 北大核心 2023年第6期803-811,共9页
相位恢复技术是波前重构技术的一个重要分支,重构的结果只取决于测量平面光强的分布,相比于其他的波前重构方法,相位恢复技术具有不需要在光路中添加额外硬件、光路简单、对光路环境的要求低、抗干扰能力强等优点,在光束整形、激光光束... 相位恢复技术是波前重构技术的一个重要分支,重构的结果只取决于测量平面光强的分布,相比于其他的波前重构方法,相位恢复技术具有不需要在光路中添加额外硬件、光路简单、对光路环境的要求低、抗干扰能力强等优点,在光束整形、激光光束净化和干涉成像等领域有着非常广阔的应用前景。相位恢复的精度及速度是评价相位恢复技术的主要准则,此领域目前文献比较繁杂,本文梳理了相位恢复算法的发展脉络,围绕相位恢复算法的收敛精度与收敛速度等核心问题,系统的介绍了迭代及光强相位恢复算法的相关研究进展,并且对相位恢复算法的发展前景进行了展望。 展开更多
关键词 计算成像 相位恢复 迭代算法 传递
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摄影光学
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《中国光学与应用光学》 2007年第2期65-65,共1页
关键词 传递函数 介质阻挡放电 图像对比度 编码标志点 DBDP 数码相机 脉冲宽度 脉冲特性 灰度曲线 阴极 晶体 电倍增管
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OTN未来的发展趋势:超大容量调度枢纽 被引量:7
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作者 许宗幸 《邮电设计技术》 2010年第1期62-64,共3页
对光传送网(OTN)的标准化、应用现状及技术挑战进行了分析,并简单介绍了阿尔卡特朗讯最新的OTN解决方案:海量智能交叉机1870TTS。
关键词 光传递 调度枢纽 交叉机
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Enhancement of Photophosphorylation and Photosynthesis in Rice by Low Concentrations of NaHSO_3 Under Field Conditions 被引量:25
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作者 王宏炜 魏家绵 +2 位作者 沈允钢 张荣铣 杨图南 《Acta Botanica Sinica》 CSCD 2000年第12期1295-1299,共5页
Spraying 1-2 mmol/L solution of NaHSO 3 on rice ( Oryza sativa L.) leaves resulted in the enhancement of net photosynthetic rate for more than three days. It was also observed that NaHSO 3 application caused incr... Spraying 1-2 mmol/L solution of NaHSO 3 on rice ( Oryza sativa L.) leaves resulted in the enhancement of net photosynthetic rate for more than three days. It was also observed that NaHSO 3 application caused increases both in ATP content in leaves and the millisecond_delayed light emission of leaves. The increase in net photosynthetic rate caused by NaHSO 3 treatment was similar to that by PMS (phenazine methosulfate) treatment. The grain yield of treated rice was enhanced approximately by 10% after duplicated application of NaHSO 3 in milk_ripening stage. It is suggested that the enhancement of photosynthesis by NaHSO 3 treatment resulted from the effect of increasing ATP supplement. Concomitant with an increase in the photosynthetic rate and ATP content in leaves, the transient increase in chlorophyll fluorescence after the termination of actinic light, which could be used as an index of the cyclic electron flow, was also enhanced by low concentration of NaHSO 3 treatment. Basing on these results it is proposed that the increase in rice photosynthesis caused by low concentrations of NaHSO 3 could be due to the stimulation of the cyclic electron flow around PSⅠ which in turn the enhancement of the coupled photophosphorylation and photosynthesis. 展开更多
关键词 cyclic electron transport millisecond delayed light emission PHOTOPHOSPHORYLATION post_illumination transient increase in chlorophyll fluorescen
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视觉系统与仪器MTF测试的差异探析 被引量:3
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作者 陈宏 程守澄 《应用光学》 CAS CSCD 2002年第2期45-48,共4页
本文首先对光学传递函数作概念性表述。基于对视觉系统定量描述其随空间频率明暗变化的视觉特性;探讨视觉系统MTF的测量。着重讨论视觉系统MTF测试和光学仪器MTF测试的差异,尤其是在原理、理论基础及实验方法和设备等方面。
关键词 视觉系统 MTF 测试 调制传递函数 视觉测试 学仪器 传递函数 人眼
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Properties of Picosecond Fluorescence of Super High-Yield Hybrid Rice
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作者 任兆玉 许晓明 +3 位作者 王水才 辛越勇 贺俊芳 匡廷云 《Acta Botanica Sinica》 CSCD 2003年第12期1442-1446,共5页
Thylakoid membrane preparations of super high-yield hybrid rice (Oryza sativa L.), Liangyoupeijiu (P9) and Shanyou 63 (SH 63) were used for investigating its spectral and time properties by using picosecond time-resol... Thylakoid membrane preparations of super high-yield hybrid rice (Oryza sativa L.), Liangyoupeijiu (P9) and Shanyou 63 (SH 63) were used for investigating its spectral and time properties by using picosecond time-resolved fluorescence spectrum measuring system. The thylakoid membrane preparations of P9 and SH 63 were excited by an Ar+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. The time constants of the excited energy transfer in these two varieties at flowering stage and grain filling stage were calculated from the experimental data. Based on the comparative studies of the time and spectral properties of the excited fluorescence in these ultrafast dynamic experiments the following was found: at both the flowering stage and grain filling stage, the speed of the excitation energy transfer, in photosystem was faster than that in photosystem II in P9 variety; and the speed of the excitation energy transfer at grain filling stage was faster than those at flowering stage for both rice varieties; the experiments also implied that the components and assembly of pigments in SH 63, but not in P9, changed during the process from flowering stage to grain filling stage for in these two rice varieties. 展开更多
关键词 super high-yield rice picosecond resolving FLUORESCENCE time constant excitation energy transfer
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Optical Study on Concentration-Driven Rayleigh-Bénard-Marangoni Convection 被引量:2
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作者 沙勇 成弘 +3 位作者 袁希钢 刘春江 孙志发 余国琮 《Transactions of Tianjin University》 EI CAS 2002年第1期22-26,共5页
By utilizing optical Schlieren method, the Rayleigh Bénard Marangoni convection in mass transfer process was observed. A recorder and a camera separately recorded dynamic and static convective flow patterns dur... By utilizing optical Schlieren method, the Rayleigh Bénard Marangoni convection in mass transfer process was observed. A recorder and a camera separately recorded dynamic and static convective flow patterns during experiments . Different organic solvents were selected to investigate the RBM effects induced by different driving mechanisms including density gradient, surface tension gradient and their combination. Thermal effects produced by solvents evaporation and solute absorption/desorption are thought as an important factor in the creation of RBM convection during the mass transfer process. Qualitative analysis of experimental results is presented on the basis of photos and videotapes that were taken as direct visual evidences. Experimental results show that the thermal effect accompanying the mass transfer can be a cause at the onset of RBM convection and can′t be neglected simply in study of RBM effect driven by mass transfer. 展开更多
关键词 Rayleigh Bénard Marangoni effect mass transfer LASER Schlieren device
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Kinetic Fluorescence Spectral Analysis of Core Antennas CP43 and CP47 of Photosystem Ⅱ with Ultrafast Time-resolved Technology
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作者 贺俊芳 王水才 +3 位作者 张舒 贺锋涛 单际修 匡廷云 《Acta Botanica Sinica》 CSCD 2001年第7期704-708,共5页
Ultrafast time_resolved fluorescence experiments have been performed with core antennas CP43 and CP47 of PS Ⅱ. Their dynamic fluorescence spectra were obtained with excitation wavelength 514.5 nm. For CP43, the emiss... Ultrafast time_resolved fluorescence experiments have been performed with core antennas CP43 and CP47 of PS Ⅱ. Their dynamic fluorescence spectra were obtained with excitation wavelength 514.5 nm. For CP43, the emission spectrum was found to be from 640 to 780 nm with a peak at ~680 nm and the lifetime of fluorescence was 3.54 ns. For CP47, the emission spectrum was from 630 to 775 nm with a peak at ~691 nm and the fluorescence lifetime was 3.22 ns. The fluorescence emission efficiencies of Chl a in CP43 and CP47 were calculated to be approximately 38.3% and 40.6%, respectively. The energy transfer from β_Car to Chl a in CP43 and CP47 was discussed. The rates of energy transfer from β_Car to Chl a were measured to be about 9.6×10 11 s -1 and 1.3×10 12 s -1 and energy transfer efficiencies 47.5% and 66.5% respectively. The edge_edge distances between β_Car and Chl a in CP43 and CP47 were estimated to be ~0.110 nm and ~0.085 nm respectively. 展开更多
关键词 core antenna CP43 CP47 β-Car Chl a energy transfer PS
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妈妈的眼睛
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作者 卢云生 李家玮 《民族音乐》 2000年第3期33-33,共1页
关键词 眼睛 中学生 光传递 歌曲 氢星 生词 波流 雷电 双眼 明亮
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The Influence of Surfactants on Chlorophyll Binding Status and Excitation Energy Transfer in Photosystem Ⅰ of Wheat
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作者 郁飞 唐崇钦 +5 位作者 辛越勇 彭德川 李良璧 匡廷云 李济云 李振声 《Acta Botanica Sinica》 CSCD 2001年第7期686-692,共7页
Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem... Surfactants are widely used in the purification and research of structure and function of the protein complexes in photosynthetic membrane. To elucidate the mechanism of interaction between surfactants and photosystem Ⅰ (PSⅠ), effects of two typical surfactants, Triton X_100 and sodium dodecyl sulfate (SDS) on PSⅠ, were studied at different concentrations. The results were: SDS led to the reduction of apparent absorption intensity and blue shift of absorption peaks; while Triton X_100 led to the decrease of apparent absorption intensity in red region and blue shift of the peak, but to the increase of apparent absorption intensity in blue region. The fourth derivative spectra show that the longwavelength (669 nm and 683 nm) absorbing chlorophyll a was affected greatly and their relative changes of absorbance were axially symmetrical. The presence of surfactant could make the long wavelength fluorescence emission decrease greatly and a new fluorescence peak appeared around 680 nm, it was obvious that the surfactant interceded the transfer of excitation energy from antenna pigments to reaction center. The surfactants might affect the microenvironment of proteins, even the structure of PSⅠ protein subunits and hence changed the binding status of pigments with protein subunits, or the pigments might be released from the subunits. All of these might affect the absorption and the transfer of excitation energy. 展开更多
关键词 SURFACTANT Photosystem CHLOROPHYLL absorption spectra fluorescence spectra
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干旱区黑果枸杞光合电子传递速率对施氮的响应 被引量:1
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作者 马兴东 郭晔红 +4 位作者 王爱敏 李梅英 于霞霞 冯洁 朱文娟 《干旱区资源与环境》 CSSCI CSCD 北大核心 2021年第5期130-136,共7页
为探明干旱区栽培黑果枸杞(Lycium ruthenicum Murr.)叶片光合电子传递速率(J)对施氮的响应,进一步完善施氮对光合特性的影响机理,本试验设置5个不同施氮(尿素,N,46%)量处理(0、0.05、0.10、0.15和0.20kg·株^(-1)),测定各处理下黑... 为探明干旱区栽培黑果枸杞(Lycium ruthenicum Murr.)叶片光合电子传递速率(J)对施氮的响应,进一步完善施氮对光合特性的影响机理,本试验设置5个不同施氮(尿素,N,46%)量处理(0、0.05、0.10、0.15和0.20kg·株^(-1)),测定各处理下黑果枸杞在不同光照强度(PAR)和CO_(2)浓度下叶片J,并通过J-PAR和J-CO_(2)的响应曲线拟合得到饱和光强(I_(sat))、饱和CO_(2)浓度(C_(i-sat))、最大电子传递速率(J_(max))和零点电子传递速率(J_(0))等参数。结果表明:1)J-PAR响应下,适当施氮对黑果枸杞叶片J_(max)和I_(sat)有一定的提高作用。当施氮量为0.15~0.20kg·株^(-1)时J_(max)最大,当施氮量为0.10~0.15kg·株^(-1)时I_(sat)最大。2)J-CO_(2)响应下,适当施氮对黑果枸杞叶片J_(0)、J_(max)和C_(i-sat)有一定的提高作用。当施氮量为0.10~0.15kg·株^(-1)时J_(0)最大,但J_(max)和C_(i-sat)受季节影响较大,J_(max)在夏果期当施氮量为0.20kg·株^(-1)时最大,在秋果期当施氮量为0.10kg·株^(-1)时最大,C_(i-sat)在夏果期当施氮量为0.20kg·株^(-1)时最大,在秋果期当施氮量为0.05kg·株^(-1)时最大。因此,适当施氮有利于I_(sat)、C_(i-sat)、J_(max)和J_(0)等参数的提高。 展开更多
关键词 干旱区 黑果枸杞 施氮量 电子传递速率-响应 电子传递速率-CO_(2)响应
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Numerical analysis of thermal distortion of the mirror in space-to-groundlaser communicationlinks 被引量:1
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作者 LI Xiao-feng ZHANG Bai-lei LIN Mi QI Li-mei 《Optoelectronics Letters》 EI 2005年第3期209-212,共4页
The thermal distortion of an optical reflector surface due to the changing sunlight in a space environment will cause shift and spreading of its reflected focus and thereby influence the performance of space-to-ground... The thermal distortion of an optical reflector surface due to the changing sunlight in a space environment will cause shift and spreading of its reflected focus and thereby influence the performance of space-to-ground laser communication links. Based on the characteristics of a low orbit satellite, the normal shift of a plan mirror caused by thermal distortion is analyzed with the software of the ANSYS of finite element analysis. A general expression of the transmitted beam from a distorted reflector surface and a counting formula for the shifts of the focus center before and after thermal distortion are deduced. The result of simulation shews that the magnitude order of the normal shift of the antenna mirror surface can be as high as tens of urad. The worse the mirror thermal distortion is, the larger the shift of the received focus center is. And the change of the shifts does not obey a linear rule. 展开更多
关键词 通信 数字分析 传递 学反射 空间环境
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Numerical analysis on heat transfer of laser diode module by equivalent electrical network method 被引量:1
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作者 YANG Ming-wei ZHOU Zhao-ying 《Optoelectronics Letters》 EI 2008年第3期180-183,共4页
Because it is complex and inconvenient to use the common temperature field calculating method and experiment method, for arialyzing heat transfer properties of laser diode module (LDM), an equivalent electrical netw... Because it is complex and inconvenient to use the common temperature field calculating method and experiment method, for arialyzing heat transfer properties of laser diode module (LDM), an equivalent electrical network method is presented in this paper. Simulation results show that the temperature stability is closely related to ambient temperature, heat sink, LDM current and TEC current. Ambient temperature and TEC controller are the dominant terms effecting on temperature control in practice, 展开更多
关键词 数字分析技术 传递 二极管 电网
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2-氰基-3-(2-氟吡啶-5-基)甲氨基-3-甲硫基氰基丙烯酸酯类化合物的合成及除草活性 被引量:12
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作者 邹小毛 郁丽敏 +6 位作者 高颍 施欢乐 裴江 刘斌 李慧芬 胡方中 杨华铮 《有机化学》 SCIE CAS CSCD 北大核心 2006年第3期337-340,共4页
设计合成了系列光系统II(PS-II)电子传递抑制剂2-氰基-3-(2-氟吡啶-5-基)甲氨基-3-甲硫基氰基丙烯酸酯类化合物.其结构经1HNMR、元素分析确证.生物活性测定表明:部分化合物显示出很好的除草活性.其中活性最好的化合物在150g/ha,对阔叶... 设计合成了系列光系统II(PS-II)电子传递抑制剂2-氰基-3-(2-氟吡啶-5-基)甲氨基-3-甲硫基氰基丙烯酸酯类化合物.其结构经1HNMR、元素分析确证.生物活性测定表明:部分化合物显示出很好的除草活性.其中活性最好的化合物在150g/ha,对阔叶杂草的防效在90%以上.构效关系研究表明:氰基丙烯酸酯的3位取代基对它们的活性影响较大.3位由(2-氟吡啶-5-基)甲氨基取代的氰基丙烯酸酯和相应的氯取代的氰基丙烯酸酯的除草活性相当或稍高. 展开更多
关键词 系统Ⅱ(PS—Ⅱ)电子传递抑制剂 2-氰基-3-(2-氟吡啶-5-基)甲氨基-3-甲硫基氰基丙烯酸酯 除草活性 构效关系
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An Alternative Scheme for Transferring Quantum States and Preparing a Quantum Network in Cavity QED 被引量:1
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作者 YANG Zhen-Biao SU Wan-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第6期1037-1040,共4页
An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the at... An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the atom-cavity field interaction is resonant, thus the time required to complete the quantum state transfer process is greatly shortened, which is very important in view of decoherence. Moreover, the present scheme does not require one mode of the cavities to be initially prepared in one-photon state, thus it is more experimentally feasible than the previous ones. 展开更多
关键词 quantum states transfer quantum network cavity QED
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