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Expression Patterns of OsPIL11,a Phytochrome-Interacting Factor in Rice,and Preliminary Analysis of Its Roles in Light Signal Transduction 被引量:1
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作者 LI Li PENG Wei-feng +3 位作者 LIU Qian-qian ZHOU Jin-jun LIANG Wei-hong XIE Xian-zhi 《Rice science》 SCIE 2012年第4期263-268,共6页
The expression patterns of OsPILll, one of six putative phytochrome-interacting factors, were analyzed in different organs of transgenic tobacco (Nicotiana tabacum). The expression of OsPIL 11 was organ-specific and... The expression patterns of OsPILll, one of six putative phytochrome-interacting factors, were analyzed in different organs of transgenic tobacco (Nicotiana tabacum). The expression of OsPIL 11 was organ-specific and was regulated by leaf development, abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA). To further explore the role of OsPIL 11 in plant light signal transduction, a plant expression vector of OsPILll was constructed and introduced into tobacco. When grown under continuous red light, OsPILll-overexpressed transgenic tobacco exhibited shorter hypocotyls and larger cotyledons and leaves compared to wild-type seedlings. When grown under continuous far-red light, however, transgenic and wild-type seedlings showed similar phenotypes. These results indicate that OsPILll is involved in red light induced de-etiolation, but not in far-red light induced de-etiolation in transgenic tobacco, which lays the foundation for dissecting the function of OsPIL11 in phytochrome-mediated light signal transduction in rice. 展开更多
关键词 RICE phytochrome-interacting factor transgenic tobacco light signal transduction
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Study of light signal receptor of Stephanopyxis palmeriana during sexual reproduction
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作者 胡韧 林均民 +1 位作者 林秋奇 韩博平 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2005年第3期330-334,共5页
We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for charac- teristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual ... We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for charac- teristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual repro- duction. The result showed that pre-illumination of 2-3h red light before darkness could induce sexualization of S. palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The result also showed high homogeneity of DNA fragment of S. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction of S. palmeriana is phytochrome B (phyB). 展开更多
关键词 DIATOM sexual reproduction PHOTOPERIOD light signal receptor
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Regulated Degradation of HFR1 Desensitizes Light Signaling in Arabidopsis
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作者 Haiyang Wang(Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853, USA) 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第S1期185-185,共1页
Arabidopsis seedlings undergo photomorphogenesis in the light and etiolation in the dark. HFR1, a bHLH transcription factor, is required for both phytochrome A (phyA)-mediated far-red and cryptochrome 1 (cry1)-mediate... Arabidopsis seedlings undergo photomorphogenesis in the light and etiolation in the dark. HFR1, a bHLH transcription factor, is required for both phytochrome A (phyA)-mediated far-red and cryptochrome 1 (cry1)-mediated blue light signaling. We report that HFR1 is a short-lived protein in darkness and is degraded through a 26S proteasome-dependent pathway. Light, irrespective of its quality, enhances HFR1 protein accumulation via promoting its stabilization. We demonstrate that HFR1 physically interacts with COP1 and that COP1 exhibits ubiquitin ligase activity toward HFR1 in vitro. In addition, we show that COP1 is required for degradation of HFR1 in vivo. Furthermore, plants overexpressing a C-terminal 161 amino acid fragment of HFR1 (CT161) display enhanced photomorphogenesis, suggesting an autonomous function of CT161 in promoting light signaling. This truncated HFR1 gene product is more stable than the full-length HFR1 protein in darkness, indicating that the COP1-interacting N-terminal portion of HFR1 is essential for COP1-mediated destabilization of HFR1. These results suggest that light enhances HFR1 protein accumulation by abrogating COP1-mediated degradation of HFR1, which is necessary and sufficient for promoting light signaling. Additionally, our results substantiate the E3 ligase activity of COP1 and its critical role in desensitizing light signaling. 展开更多
关键词 HFR Regulated Degradation of HFR1 Desensitizes light signaling in Arabidopsis
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A Workable Solution for Reducing the Large Number of Vehicle and Pedestrian Accidents Occurring on a Yellow Light
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作者 Pranav Gupta Silki Arora 《Journal of Transportation Technologies》 2024年第1期82-87,共6页
Traffic intersections are incredibly dangerous for drivers and pedestrians. Statistics from both Canada and the U.S. show a high number of fatalities and serious injuries related to crashes at intersections. In Canada... Traffic intersections are incredibly dangerous for drivers and pedestrians. Statistics from both Canada and the U.S. show a high number of fatalities and serious injuries related to crashes at intersections. In Canada, during 2019, the National Collision Database shows that 28% of traffic fatalities and 42% of serious injuries occurred at intersections. Likewise, the U.S. National Highway Traffic Administration (NHTSA) found that about 40% of the estimated 5,811,000 accidents in the U.S. during the year studied were intersection-related crashes. In fact, a major survey by the car insurance industry found that nearly 85% of drivers could not identify the correct action to take when approaching a yellow traffic light at an intersection. One major reason for these accidents is the “yellow light dilemma,” the ambiguous situation where a driver should stop or proceed forward when unexpectedly faced with a yellow light. This situation is even further exacerbated by the tendency of aggressive drivers to inappropriately speed up on the yellow just to get through the traffic light. A survey of Canadian drivers conducted by the Traffic Injury Research Foundation found that 9% of drivers admitted to speeding up to get through a traffic light. Another reason for these accidents is the increased danger of making a left-hand turn on yellow. According to the National Highway Traffic Safety Association (NHTSA), left turns occur in approximately 22.2% of collisions—as opposed to just 1.2% for right turns. Moreover, a study by CNN found left turns are three times as likely to kill pedestrians than right turns. The reason left turns are so much more likely to cause an accident is because they take a driver against traffic and in the path of oncoming cars. Additionally, most of these left turns occur at the driver’s discretion—as opposed to the distressingly brief left-hand arrow at busy intersections. Drive Safe Now proposes a workable solution for reducing the number of accidents occurring during a yellow light at intersections. We believe this fairly simple solution will save lives, prevent injuries, reduce damage to public and private property, and decrease insurance costs. 展开更多
关键词 Traffic Accidents Yellow light Traffic light signals INTERSECTION Crashes Collision Traffic Fatalities Traffic Injuries Vehicles SAFETY Speed Limit Driving Pedestrians Bicyclists MOTORCYCLISTS Caution Line Yellow light Dilemma Left Hand Turn on Yellow Distance Smart Road Technology Signs Signage Autonomous Vehicles AVs Road Safety IoT Internet of Things Infrastructure Accident Reduction Driving Habits Stop Line Red light Jumping Pedestrian Safety Caution light Stopping at Intersection Safety at Intersections
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人重组LIGHT-Fc分子的真核表达及其抗肿瘤活性研究 被引量:1
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作者 黄钢 白云 +1 位作者 姜曼 黎万玲 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2003年第5期499-502,共4页
目的 :构建人LIGHT Fc基因的真核表达质粒 ,并表达获得有较高生物学活性的纯化人LIGHT Fc融合蛋白。方法 :从cDNA文库中PCR扩增LIGHT全长编码基因 ,并导入克隆载体。测序证实后 ,继续用PCR扩增其膜外区cDNA ,用重叠延伸技术(SOE)引入CD... 目的 :构建人LIGHT Fc基因的真核表达质粒 ,并表达获得有较高生物学活性的纯化人LIGHT Fc融合蛋白。方法 :从cDNA文库中PCR扩增LIGHT全长编码基因 ,并导入克隆载体。测序证实后 ,继续用PCR扩增其膜外区cDNA ,用重叠延伸技术(SOE)引入CD137信号肽基因。将SOE产物与hIgG1Fc基因一起装入真核表达载体pcDNA3中 ,瞬时转染 2 93T细胞 ,用夹心ELISA检测其表达情况 ,经蛋白A亲和纯化 ,用SDS PAGE检测其纯度与Mr,并以肿瘤细胞为靶细胞 ,检测其生物学活性。结果 :测序证实构建的LIGHT与LIGHT FccDNA阅读框完整 ,连接部位序列正确 ;ELISA和SDS PAGE证实LIGHT Fc融合蛋白的表达与纯度 ;MTT证明人LIGHT Fc蛋白对一些肿瘤细胞系具有生长抑制作用。结论 :获得了有抗肿瘤活性的纯化hLIGHT Fc融合蛋白 ,为探讨LIGHT在免疫自稳调节中的地位、结合相应受体后的动力学与信号转导机制 。 展开更多
关键词 light light-Fc 信号肽 重叠延伸 蛋白A亲和层析 抗肿瘤 生物学活性
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基于LIGHT-HVEM信号通路探讨健脾养血祛风方对脾虚型慢性湿疹小鼠作用机制 被引量:3
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作者 黄丽霞 高晶 +2 位作者 陈兴 朱卉雯 于萍 《辽宁中医药大学学报》 CAS 2023年第3期1-5,F0003,共6页
目的基于肿瘤坏死因子超家族第14个成员(LIGHT)-疱疹病毒入侵介质(HVEM)信号通路探讨健脾养血祛风方对脾虚型慢性湿疹小鼠的作用机制。方法60只雄性昆明小鼠随机分为空白对照组10只和模型组50只。模型组采用小剂量二硝基氯苯(DNCB)反复... 目的基于肿瘤坏死因子超家族第14个成员(LIGHT)-疱疹病毒入侵介质(HVEM)信号通路探讨健脾养血祛风方对脾虚型慢性湿疹小鼠的作用机制。方法60只雄性昆明小鼠随机分为空白对照组10只和模型组50只。模型组采用小剂量二硝基氯苯(DNCB)反复涂抹联合番泻叶灌服建立脾虚型慢性湿疹小鼠模型。造模成功的50只小鼠随机分成模型对照组、西药治疗组、中药低剂量治疗组、中药中剂量治疗组和中药高剂量治疗组,每组10只。西药治疗组予盐酸左西替利嗪片灌胃,中药各剂量组予健脾养血祛风方灌胃,空白对照组和模型对照组予等体积生理盐水灌胃,各组均连续给药14 d。观察背部皮肤肿胀度和组织形态学变化,检测血清白细胞介素2(IL-2)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)表达水平,皮肤LIGHT、HVEM蛋白表达水平。结果与空白对照组比较,模型对照组小鼠皮肤肿胀度和血清IL-2、IL-6、TNF-α表达水平显著升高(P<0.01),皮肤组织形态学表现呈现慢性湿疹病理改变,皮肤LIGHT、HVEM蛋白表达水平显著升高(P<0.01);与模型对照组比较,西药治疗组、中药高剂量治疗组小鼠皮肤肿胀度和血清IL-2、IL-6、TNF-α表达水平显著降低(P<0.05或P<0.01),皮肤组织形态学表现明显改善,西药治疗组、中药治疗组皮肤LIGHT、HVEM蛋白表达水平显著降低(P<0.01)。结论健脾养血祛风方对脾虚型慢性湿疹小鼠具有抗炎和免疫调节作用,以高剂量效果最佳,其作用机制可能是通过抑制LIGHT-HVEM信号通路,降低血清IL-2、IL-6、TNF-α表达水平,调节Th1/Th2细胞因子动态平衡,从而有效改善皮肤肿胀度和皮肤组织病理形态。 展开更多
关键词 脾虚 慢性湿疹 健脾养血祛风方 肿瘤坏死因子超家族第14个成员-疱疹病毒入侵介质信号通路
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SVC Light次同步振荡阻尼特性分析 被引量:5
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作者 郑超 唐晓骏 +2 位作者 马世英 苗友忠 吴涛 《中国电力》 CSCD 北大核心 2010年第8期34-39,共6页
以绝缘栅双极晶闸管(IGBT)和脉宽调制(PWM)控制为基础的新型静止无功补偿装置(SVC Light),可快速调节其与交流系统间交换的感性或容性无功功率,具有提高振荡阻尼特性的能力。介绍SVC Light的工作原理,推导出三相abc坐标系下的数学模型,... 以绝缘栅双极晶闸管(IGBT)和脉宽调制(PWM)控制为基础的新型静止无功补偿装置(SVC Light),可快速调节其与交流系统间交换的感性或容性无功功率,具有提高振荡阻尼特性的能力。介绍SVC Light的工作原理,推导出三相abc坐标系下的数学模型,建立基于受控电压源和受控电流源的等效仿真模型,并设计出基于比例-积分调节器的直流电压、无功功率和交流母线电压控制器。利用复转矩系数的时域实现方法——测试信号法,分析SVC Light不同控制方式、主电路参数以及控制器参数对发电机电气阻尼特性的影响。研究结果表明,SVC Light在配置次同步附加阻尼控制器后,通过动态调节其与交流系统间交换的无功功率,可以显著增加发电机电气阻尼,有效抑制由串联电容补偿引发的发电机轴系振荡。 展开更多
关键词 新型静止无功补偿器 次同步振荡 测试信号法
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基于ESPRIT-PSA与LightGBM算法的感应电动机转子断条数目诊断新方法
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作者 许伯强 王晨曦 何俊驰 《华北电力大学学报(自然科学版)》 CAS 北大核心 2023年第5期27-34,共8页
提出一种基于旋转不变信号参数估计技术ESPRIT(Estimation of signal parameters via rotational invariance technique)、模式搜索算法PSA(Pattern search algorithm)与轻型梯度提升机LightGBM(Light gradient boosting machine)结合... 提出一种基于旋转不变信号参数估计技术ESPRIT(Estimation of signal parameters via rotational invariance technique)、模式搜索算法PSA(Pattern search algorithm)与轻型梯度提升机LightGBM(Light gradient boosting machine)结合的感应电动机转子断条数目诊断新方法。模拟了转子断条故障下的瞬时无功功率信号并用其衡量ESPRIT-PSA的性能。结果表明:ESPRIT-PSA只需短时数据就能准确测量瞬时无功功率信号中的转子断条故障特征分量。随后,为解决现有的电机瞬时无功功率信号分析MIRPSA(Motor instantaneous reactive power signal analysis)类方法无法准确诊断转子断条数目的问题,引入LightGBM对转子断条故障进行多分类以准确诊断转子断条数目。最后针对一台异步电动机进行转子断条诊断实验,结果表明:该方法是有效的,并且因将瞬时无功功率作为分析信号而适用于电机低转差率的情况。 展开更多
关键词 异步电动机 转子断条 故障诊断 旋转不变信号参数估计技术 轻型梯度提升机 电机瞬时无功功率信号分析
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Light regulation of horticultural crop nutrient uptake and utilization 被引量:5
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作者 Jin Xu Zhixin Guo +2 位作者 Xiaochun Jiang Golam Jalal Ahammed Yanhong Zhou 《Horticultural Plant Journal》 SCIE CSCD 2021年第5期367-379,共13页
Plants demonstrate dynamic changes in molecular structures under fluctuating light conditions.Accumulating evidence suggests that light plays a vital role in plant growth and morphogenesis.In particular,light has a ro... Plants demonstrate dynamic changes in molecular structures under fluctuating light conditions.Accumulating evidence suggests that light plays a vital role in plant growth and morphogenesis.In particular,light has a role in the absorption and utilization of nutrients in plants.Despite significant progress in understanding the mechanism of nutrient acquisition and assimilation,how light affects and regulates ion uptake remains a question.Studies in model plants,Arabidopsis thaliana,suggest that light affects the nutrient utilization in roots through a complex regulatory network;nonetheless,the molecular mechanisms underlying the various effects of light on these processes in crop plants remain fragmentary.In this review,we discuss the light effects(light quality,light intensity,and photoperiod)on nutrient uptake and utilization in horticultural crops for optimizing crop productivity and increasing fertilizer use efficiency. 展开更多
关键词 light signaling Nutrient utilization Horticultural crops PHYTOCHROME
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Resolution and noise in ghost imaging with classical thermal light 被引量:3
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作者 程静 韩申生 严以京 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第9期2002-2006,共5页
The resolution and classical noise in ghost imaging with a classical thermal light are investigated theoretically. For ghost imaging with a Gaussian Schell model source, the dependences of the resolution and noise on ... The resolution and classical noise in ghost imaging with a classical thermal light are investigated theoretically. For ghost imaging with a Gaussian Schell model source, the dependences of the resolution and noise on the spatial coherence of the source and the aperture in the imaging system are discussed and demonstrated by using numerical simulations. The results show that an incoherent source and a large aperture will lead to a good image quality and small noise. 展开更多
关键词 ghost imaging thermal light signal-to-noise rate
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Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy via the AMPK-mT OR-ULK1 signaling pathway 被引量:53
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作者 Jin-Feng Wang Zhi-Gang Mei +7 位作者 Yang Fu Song-Bai Yang Shi-Zhong Zhang Wei-Feng Huang Li Xiong Hua-Jun Zhou Wei Tao Zhi-Tao Feng 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第6期989-998,共10页
Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the c... Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin(50 or 100 mg/kg) reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury. 展开更多
关键词 nerve regeneration PUERARIN AUTOPHAGY cerebral ischemia/reperfusion AMPK-m TOR-ULK1 signaling pathway light chain 3 p62 ischemic stroke AMPK/m TOR traditional Chinese medicine middle cerebral artery occlusion neural regeneration
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CD160/BTLA-HVEM-LIGHT/LT-α共信号通路与单纯疱疹病毒性角膜基质炎的研究 被引量:2
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作者 谭田畅(综述) 夏丽坤(审校) 《中华实验眼科杂志》 CAS CSCD 北大核心 2018年第7期564-569,共6页
单纯疱疹病毒性角膜基质炎(HSK)是主要由CD4^+ T细胞介导的免疫病理性疾病,是可致盲的角膜感染性疾病之一。单纯疱疹病毒(HSV)进入介导子(HVEM)又名TNFRSF14,在病毒感染时可以通过病毒表面糖蛋白D(gD)介导HSV进入细胞。目前... 单纯疱疹病毒性角膜基质炎(HSK)是主要由CD4^+ T细胞介导的免疫病理性疾病,是可致盲的角膜感染性疾病之一。单纯疱疹病毒(HSV)进入介导子(HVEM)又名TNFRSF14,在病毒感染时可以通过病毒表面糖蛋白D(gD)介导HSV进入细胞。目前研究证实存在5种配体与HVEM结合,分别为HSV-gD、BALT、CD160、LIGHT和淋巴毒素α(LT-α)。HSV-gD与HVEM结合能够促进病毒包膜与细胞的融合,介导病毒在细胞间的扩散和释放。在T细胞的活化和增生中,HVEM-LIGHT/LT-α提供协同刺激信号,HVEM-BTLA/CD160提供协同抑制信号,此双向作用使HVEM成为一个"分子开关",共同调节机体免疫应答。本文分别阐述HVEM通过与不同的配体结合所发挥不同的生物学作用,并结合CD160/BTLA-HVEM-LIGHT/LT-α共信号通路在HSK的相关实验研究,深入了解HSK的发病机制,并为HSK的有效治疗提供思路。通过有效的临床干预降低炎性免疫反应,从而达到对自身免疫性疾病的复发和慢性免疫性疾病的治疗作用。 展开更多
关键词 单纯疱疹病毒性角膜基质炎 HVEM-BTLA/CD160 HVEM-light/LT-α 信号通路 发病机制
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Technique of Position Sensitive Detector with Alternating Light Source
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作者 SU Meijun(Hefei University of Technology,Hefei 230009,CHN) 《Semiconductor Photonics and Technology》 CAS 1997年第3期228-231,共4页
The signal processing circuits of position sensitive detector(PSD) with alternating light source are presented.The measuring device of PSD with alternating light source can effectively eliminate the interference made ... The signal processing circuits of position sensitive detector(PSD) with alternating light source are presented.The measuring device of PSD with alternating light source can effectively eliminate the interference made by light noise signal. 展开更多
关键词 light Noise signal light Sources Position Sensitive Detectors
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基于轨迹数据的非机动车左转信号灯安全效应评估
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作者 王正武 谢静怡 +2 位作者 王杰 邢璐 朱全军 《长沙理工大学学报(自然科学版)》 CAS 2024年第1期164-173,共10页
【目的】对城市交叉口采用的左转非机动车信号灯设施进行交通安全性量化评估。【方法】提出一种基于拓展碰撞时间(extended time to collision,ETTC)指标的左转非机动车信号灯安全效应评估方法。针对现有的碰撞时间(time to collision,T... 【目的】对城市交叉口采用的左转非机动车信号灯设施进行交通安全性量化评估。【方法】提出一种基于拓展碰撞时间(extended time to collision,ETTC)指标的左转非机动车信号灯安全效应评估方法。针对现有的碰撞时间(time to collision,TTC)指标不适于评估交叉口左转非机动车冲突的问题,考虑非机动车车辆尺寸与加速度对交通冲突的影响,采用拓展碰撞时间指标,评估交叉口非机动车交通冲突。收集长沙市4个信号交叉口的视频大数据,利用视频软件Tracker提取车辆微观轨迹后,开展案例分析。【结果】左转非机动车信号灯在时间上明确了非机动车的通行权,其设置能显著降低非机动车冲突率,在平峰、高峰时段非机动车冲突率分别降低了40.11%、25.27%。在直行相位末期、左转相位即将启亮时,设置组的左转非机动车在待行区等待,冲突率降为0;而对比组近50%的非机动车违规左转,冲突严重。设置左转非机动车信号灯的改善效果随非机动车流量的增大呈先增加后降低趋势,而随机动车流量的增大呈逐步波动下降趋势。【结论】本研究揭示了非机动车左转信号灯的设置对减少交叉口交通冲突的影响,可为城市交叉口非机动车交通安全管控提供有益参考。 展开更多
关键词 交通工程 交叉口冲突 轨迹数据 非机动车信号灯 拓展碰撞时间
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光强非线性响应下的光致热弹光谱光强修正
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作者 陈祥 刘浩 +3 位作者 姚路 许振宇 胡迈 阚瑞峰 《光学精密工程》 EI CAS CSCD 北大核心 2024年第3期317-323,共7页
提出了基于光强非线性响应的光致热弹光谱光强修正方法,实现了激光光强的准确修正。控制DFB激光器工作于波长调制模式,设置激光调制频率为16369.75 Hz,通过光纤放大器增强其出射光强非线性项的幅值,光束经多次反射池后汇聚于石英音叉根... 提出了基于光强非线性响应的光致热弹光谱光强修正方法,实现了激光光强的准确修正。控制DFB激光器工作于波长调制模式,设置激光调制频率为16369.75 Hz,通过光纤放大器增强其出射光强非线性项的幅值,光束经多次反射池后汇聚于石英音叉根部激发光热信号,采用数字锁相放大器解调得到对应的谐波信号,通过多项式拟合谐波信号背景,反演得到与浓度及光强分别对应的谐波信号。实验结果表明,当光强从22.03 mW变化至3.16 mW,谐波信号背景幅值与光强具有良好的线性关系,线性相关系数大于0.998,归一化后的谐波信号幅值波动小于0.37%。针对甲烷测量,系统在较大的浓度范围内具有良好的线性响应,谐波信号信噪比表明系统的最低检测限达0.22×10-6。该研究为光致热弹光谱的光强修正提供了一种新的方法,可有效提高LITES系统在长期测量应用中的稳定性。 展开更多
关键词 光致热弹光谱 谐波信号 非线性响应 多项式拟合 光强修正
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Deep Learning-Based Control System Design for Emergency Vehicles through Intersections
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作者 Dingru Li Yinghui He +1 位作者 Yuanbo Yang Jiale Xu 《Journal of Electronic Research and Application》 2024年第6期208-221,共14页
This paper addresses the challenge of integrating priority passage for emergency vehicles with optimal intersection control in modern urban traffic. It proposes an innovative strategy based on deep learning to enable ... This paper addresses the challenge of integrating priority passage for emergency vehicles with optimal intersection control in modern urban traffic. It proposes an innovative strategy based on deep learning to enable emergency vehicles to pass through intersections efficiently and safely. The research aims to develop a deep learning model that utilizes intersection violation monitoring cameras to identify emergency vehicles in real time. This system adjusts traffic signals to ensure the rapid passage of emergency vehicles while simultaneously optimizing the overall efficiency of the traffic system. In this study, OpenCV is used in combination with Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN) to jointly complete complex image processing and analysis tasks, to realize the purpose of fast travel of emergency vehicles. At the end of this study, the principle of the You Only Look Once (YOLO) algorithm can be used to design a website and a mobile phone application (app) to enable private vehicles with emergency needs to realize emergency passage through the application, which is also of great significance to improve the overall level of urban traffic management, reduce traffic congestion and promote the development of related technologies. 展开更多
关键词 Emergency vehicle priority Deep learning signal light adjustment Traffic congestion reduction Trajectory optimization
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植物侧枝发育的遗传基础及激素、代谢与环境调控 被引量:1
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作者 陈尚昱 宋雪薇 +3 位作者 齐振宇 周艳虹 喻景权 夏晓剑 《浙江农业学报》 CSCD 北大核心 2024年第3期690-703,共14页
植株形态的多样性有利于植物适应环境,而侧枝发育是株型的决定因素之一。侧枝发育与产品器官形成密切相关,也会影响光合产物的分配,以及产量和品质。侧枝的形成包括腋生分生组织起始、侧芽的活化和侧芽持续生长等不同阶段。这些过程受... 植株形态的多样性有利于植物适应环境,而侧枝发育是株型的决定因素之一。侧枝发育与产品器官形成密切相关,也会影响光合产物的分配,以及产量和品质。侧枝的形成包括腋生分生组织起始、侧芽的活化和侧芽持续生长等不同阶段。这些过程受到遗传、激素、代谢和环境等方面的共同调控。文章总结了腋生分生组织形成及侧芽活化过程中的关键转录因子及其作用机制,不同植物激素的功能、信号途径和相互作用,以及糖信号和光环境如何通过激素信号网络调控侧枝发育,并对生物钟和表观遗传修饰在侧枝发育中的作用,以及利用基因编辑和环境控制等调控作物株型进行了展望。 展开更多
关键词 侧枝发育 植物激素 糖信号 光环境 转录因子
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可见光通信网络信号非线性失真自适应校正方法研究
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作者 洪年芳 席艳 《激光杂志》 CAS 北大核心 2024年第9期108-112,共5页
可见光通信网络是现今通信领域中的主要构成部分之一,但其应用的物理设备(LED照明设备)具有非线性特征,致使可见光通信网络信号出现非线性失真情况,影响着用户通信的质量,故提出可见光通信网络信号非线性失真自适应校正方法研究。通过... 可见光通信网络是现今通信领域中的主要构成部分之一,但其应用的物理设备(LED照明设备)具有非线性特征,致使可见光通信网络信号出现非线性失真情况,影响着用户通信的质量,故提出可见光通信网络信号非线性失真自适应校正方法研究。通过深入分析可知信号非线性失真分为非线性转换失真和非线性限幅失真,以此为基础,设计信号非线性失真校正电路(DG预失真校正电路与DP预失真校正电路),引入自适应算法制定信号非线性失真自适应校正架构,确定信号非线性失真自适应校正公式,从而实现了信号非线性失真的有效校正。实验数据显示:应用提出方法获得的信号非线性失真自适应校正结果中不存在非线性失真现象,通信信号接收误码率最小值为3%,充分证实了提出方法应用性能更加优质。 展开更多
关键词 通信信号 自适应 信号校正 非线性失真 可见光通信网络 限幅失真
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Novel Frame Shift and Integral Technique for Enhancing Low-Light-Level Moving Images
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作者 宋勇 郝群 王涌天 《Journal of Beijing Institute of Technology》 EI CAS 2006年第1期91-96,共6页
A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on differe... A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on difference processing. To obtain spatial relativity, images are shifted according to the motion parameters. As a result, the processing of integral and average can be applied to images that have been shifted. The technique of frame shift and integral that includes the algorithm of motion parameter determination is discussed, experiments with low light level moving image sequences are also described. The experiment results show the effectiveness and the robustness of the parameter determination algorithm, and the improvement in the signal-to-noise ratio (SNR) of low light level moving images. 展开更多
关键词 frame integral low light level image moving image sequence signal-to-noise ratio (SNR)
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基于RSSR融合RNGO-Elman神经网络的室内可见光定位
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作者 张慧颖 盛美春 +2 位作者 梁士达 马成宇 李月月 《半导体光电》 CAS 北大核心 2024年第3期449-457,共9页
针对动态环境下基于接收信号强度的传统可见光定位方法定位精度低、稳定性差等问题,提出一种基于接收信号强度比的改进北方苍鹰算法(NGO)优化Elman神经网络(RNGOElman)的室内可见光定位系统。提出选择一个辅助参考点,将待测参考点与辅... 针对动态环境下基于接收信号强度的传统可见光定位方法定位精度低、稳定性差等问题,提出一种基于接收信号强度比的改进北方苍鹰算法(NGO)优化Elman神经网络(RNGOElman)的室内可见光定位系统。提出选择一个辅助参考点,将待测参考点与辅助参考点的接收信号强度比值和接收机的真实位置作为训练集数据,建立不受动态环境影响的指纹数据库。针对NGO算法收敛速度慢、容易陷入局部最优等问题,利用折射反向学习策略初始化种群,增加种群多样性,引入非线性权重因子来加快收敛速度,避免陷入局部最优。使用优化后的NGO算法来优化Elman神经网络的初始权值和阈值,构建RNGO-Elman动态定位预测模型。仿真结果表明,在4m×4m×3m的实验空间下,优化后的RNGO-Elman定位模型平均定位误差为1.34cm,定位精度相较于Elman定位算法、NGO-Elman定位算法分别提高了82%,21%。在LED发射功率波动时,基于RSSR的RNGO-Elman定位误差为1.29cm,1.38cm。所提可见光定位方法具有定位精度高、定位性能稳定等优点。 展开更多
关键词 光通信 北方苍鹰算法 ELMAN神经网络 接收信号强度比 可见光定位
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