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斯托克斯定理的形式化及其初步应用
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作者 刘永梅 王国辉 +3 位作者 关永 张景芝 施智平 董璐 《计算机工程与科学》 北大核心 2025年第6期1050-1061,共12页
斯托克斯定理是场论中的重要定理之一,它在流体力学、电磁学等领域都有广泛的应用。然而在实际应用中,斯托克斯定理前提条件的满足往往得不到正式的验证,这就存在一定的风险。因此,有必要对斯托克斯定理进行验证。基于斯托克斯定理的数... 斯托克斯定理是场论中的重要定理之一,它在流体力学、电磁学等领域都有广泛的应用。然而在实际应用中,斯托克斯定理前提条件的满足往往得不到正式的验证,这就存在一定的风险。因此,有必要对斯托克斯定理进行验证。基于斯托克斯定理的数学定义,构建其形式化模型,通过分析斯托克斯定理的数学证明过程,得出其形式化证明推导思路,根据分析、构建和验证目标,完成定理的形式化证明,最后将斯托克斯定理证明应用到管道流量设计模型的验证中。 展开更多
关键词 形式化验证 定理证明 斯托克斯定理 HOL Light
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单球驱动平衡机器人运动学和动力学形式化验证
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作者 张善强 张景芝 +2 位作者 施智平 王国辉 关永 《软件学报》 北大核心 2025年第8期3462-3476,共15页
单球驱动平衡机器人是一种具有全向运动性的机器人,其灵活性能在狭小或复杂环境中得到充分体现,因此受到广泛关注.在该型机器人运动学和动力学设计过程中,保证其模型的正确性至关重要.基于测试和仿真的传统方法难以穷尽系统所有状态,因... 单球驱动平衡机器人是一种具有全向运动性的机器人,其灵活性能在狭小或复杂环境中得到充分体现,因此受到广泛关注.在该型机器人运动学和动力学设计过程中,保证其模型的正确性至关重要.基于测试和仿真的传统方法难以穷尽系统所有状态,因此可能无法捕捉到某些设计缺陷或潜在的安全风险.为确保单球驱动平衡机器人满足安全攸关机器人的正确性、安全性验证要求,在定理证明器HOL Light中,基于实分析库、矩阵分析库、机器人运动学和动力学库等定理证明库,构建单球驱动平衡机器人运动学和动力学的形式化模型,并进行高阶逻辑推导与证明. 展开更多
关键词 单球驱动平衡机器人 运动学和动力学 形式化验证 定理证明 HOL Light
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Simulation of light environment in a serrated photovoltaic greenhouse and optimization of daylighting roofs based on Design Builder
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作者 LIU Jian WU Xuyong +2 位作者 WANG Baolong WU Qingsen TIAN Libo 《农业工程学报》 北大核心 2025年第7期211-221,共11页
In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still rel... In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions. 展开更多
关键词 photovoltaic greenhouse annual average daily light integral greenhouse design parameters DAYLIGHTING tropical regions
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Development of an active-detection mid-wave infrared search and track system based on "cat-eye effect"
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作者 ZHOU Pan-Wei DING Xue-Zhuan +1 位作者 LI Fan-Ming YE Xi-Sheng 《红外与毫米波学报》 北大核心 2025年第4期617-629,共13页
In order to meet the urgent need of infrared search and track applications for accurate identification and positioning of infrared guidance aircraft,an active-detection mid-wave infrared search and track system(ADMWIR... In order to meet the urgent need of infrared search and track applications for accurate identification and positioning of infrared guidance aircraft,an active-detection mid-wave infrared search and track system(ADMWIRSTS)based on"cat-eye effect"was developed.The ADMWIRSTS mainly consists of both a light beam control subsystem and an infrared search and track subsystem.The light beam control subsystem uses an integrated opto-mechanical two-dimensional pointing mirror to realize the control function of the azimuth and pitch directions of the system,which can cover the whole airspace range of 360°×90°.The infrared search and track subsystem uses two mid-wave infrared cooled 640×512 focal plane detectors for co-aperture beam expanding,infrared and illumination laser beam combining,infrared search,and two-stage track opto-mechanical design.In this work,the system integration design and structural finite-element analysis were conducted,the search imaging and two-stage track imaging for external scenes were performed,and the active-detection technologies were experimentally verified in the laboratory.The experimental investigation results show that the system can realize the infrared search and track imaging,and the accurate identification and positioning of the mid-wave infrared guidance,or infrared detection system through the echo of the illumination laser.The aforementioned work has important technical significance and practical application value for the development of compactly-integrated high-precision infrared search and track,and laser suppression system,and has broad application prospects in the protection of equipment,assets and infrastructures. 展开更多
关键词 active-detection mid-wave infrared search and track "cat-eye effect" illumination laser light beam control
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Study on Color Difference of Color Reproduction of 3D Objects
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作者 GU Chong DENG Yi-qiang 《印刷与数字媒体技术研究》 北大核心 2025年第4期33-38,69,共7页
To investigate the applicability of four commonly used color difference formulas(CIELAB,CIE94,CMC(1:1),and CIEDE2000)in the printing field on 3D objects,as well as the impact of four standard light sources(D65,D50,A,a... To investigate the applicability of four commonly used color difference formulas(CIELAB,CIE94,CMC(1:1),and CIEDE2000)in the printing field on 3D objects,as well as the impact of four standard light sources(D65,D50,A,and TL84)on 3D color difference evaluations,50 glossy spheres with a diameter of 2cm based on the Sailner J4003D color printing device were created.These spheres were centered around the five recommended colors(gray,red,yellow,green,and blue)by CIE.Color difference was calculated according to the four formulas,and 111 pairs of experimental samples meeting the CIELAB gray scale color difference requirements(1.0-14.0)were selected.Ten observers,aged between 22 and 27 with normal color vision,were participated in this study,using the gray scale method from psychophysical experiments to conduct color difference evaluations under the four light sources,with repeated experiments for each observer.The results indicated that the overall effect of the D65 light source on 3D objects color difference was minimal.In contrast,D50 and A light sources had a significant impact within the small color difference range,while the TL84 light source influenced both large and small color difference considerably.Among the four color difference formulas,CIEDE2000 demonstrated the best predictive performance for color difference in 3D objects,followed by CMC(1:1),CIE94,and CIELAB. 展开更多
关键词 Color difference formula 3D objects Light source Gray scale Normalized residual sum of squares
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Na and O Co-doped Carbon Nitride for Efficient Photocatalytic Hydrogen Evolution
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作者 CHEN Libo SHENG Ying +3 位作者 WU Ming SONG Jiling JIAN Jian SONG Erhong 《无机材料学报》 北大核心 2025年第5期552-560,I0011,I0012,共11页
Elemental doping is an effective strategy for tuning the band structure of graphite carbon nitride(CN)to enhance its photocatalytic performance.In this study,sodium(Na)and oxygen(O)co-doped carbon nitride(Na/O-CN_(x),... Elemental doping is an effective strategy for tuning the band structure of graphite carbon nitride(CN)to enhance its photocatalytic performance.In this study,sodium(Na)and oxygen(O)co-doped carbon nitride(Na/O-CN_(x),x=1.0,2.0,3.0,4.0)was synthesized via solid-phase reaction of sodium citrate(NaCA)and pure CN powder in the Teflon-sealed autoclave under air conditions at 180℃.Surface area of Na/O-CN_(3.0) is measured to be 18.8 m^(2)/g,increasing by 60.7%compared to that of pure CN(11.7 m^(2)/g).Bandgap energy of Na/O-CN_(3.0) is determined to be 2.68 eV,marginally lower than that of pure CN(2.70 eV),thereby enhancing its capacity for sunlight absorption.Meanwhile,the incorporation of Na and O atoms into Na/O-CN_(x) is found to effectively reduce recombination rates of photogenerated electron-hole pairs.As a result,Na/O-CN_(x) samples exhibit markedly enhanced photocatalytic hydrogen evolution activity under visible light irradiation.Notably,the optimal Na/O-CN_(3.0) sample achieves a photocatalytic hydrogen production rate of 103.2μmol·g^(–1)·h^(–1),which is 8.2 times greater than that of pure CN(11.2μmol·g^(–1)·h^(–1)).Furthermore,a series of Na/O-CN_(x)-yO_(2)(y=0,20%,40%,60%,80%,100%)samples were prepared by modulating the oxygen content within reaction atmosphere.The catalytic performance evaluations reveal that the incorporation of both Na and O atoms in Na/O-CN_(3.0) enhances photocatalytic activity.This study also introduces novel methodologies for synthesis of metal atom-doped CN materials at lower temperature,highlighting the synergistic effect of Na and O atoms in photocatalytic hydrogen production of Na/O-CN_(x) samples. 展开更多
关键词 Na and O co-doped carbon nitride synergistic effect visible light photocatalytic hydrogen evolution
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Machine learning models for optimization, validation, and prediction of light emitting diodes with kinetin based basal medium for in vitro regeneration of upland cotton (Gossypium hirsutum L.)
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作者 ÖZKAT Gözde Yalçın AASIM Muhammad +2 位作者 BAKHSH Allah ALI Seyid Amjad ÖZCAN Sebahattin 《Journal of Cotton Research》 2025年第2期228-241,共14页
Background Plant tissue culture has emerged as a tool for improving cotton propagation and genetics,but recalcitrance nature of cotton makes it difficult to develop in vitro regeneration.Cotton’s recalcitrance is inf... Background Plant tissue culture has emerged as a tool for improving cotton propagation and genetics,but recalcitrance nature of cotton makes it difficult to develop in vitro regeneration.Cotton’s recalcitrance is influenced by genotype,explant type,and environmental conditions.To overcome these issues,this study uses different machine learning-based predictive models by employing multiple input factors.Cotyledonary node explants of two commercial cotton cultivars(STN-468 and GSN-12)were isolated from 7–8 days old seedlings,preconditioned with 5,10,and 20 mg·L^(-1) kinetin(KIN)for 10 days.Thereafter,explants were postconditioned on full Murashige and Skoog(MS),1/2MS,1/4MS,and full MS+0.05 mg·L^(-1) KIN,cultured in growth room enlightened with red and blue light-emitting diodes(LED)combination.Statistical analysis(analysis of variance,regression analysis)was employed to assess the impact of different treatments on shoot regeneration,with artificial intelligence(AI)models used for confirming the findings.Results GSN-12 exhibited superior shoot regeneration potential compared with STN-468,with an average of 4.99 shoots per explant versus 3.97.Optimal results were achieved with 5 mg·L^(-1) KIN preconditioning,1/4MS postconditioning,and 80%red LED,with maximum of 7.75 shoot count for GSN-12 under these conditions;while STN-468 reached 6.00 shoots under the conditions of 10 mg·L^(-1) KIN preconditioning,MS with 0.05 mg·L^(-1) KIN(postconditioning)and 75.0%red LED.Rooting was successfully achieved with naphthalene acetic acid and activated charcoal.Additionally,three different powerful AI-based models,namely,extreme gradient boost(XGBoost),random forest(RF),and the artificial neural network-based multilayer perceptron(MLP)regression models validated the findings.Conclusion GSN-12 outperformed STN-468 with optimal results from 5 mg·L^(-1) KIN+1/4MS+80%red LED.Application of machine learning-based prediction models to optimize cotton tissue culture protocols for shoot regeneration is helpful to improve cotton regeneration efficiency. 展开更多
关键词 Machine learning COTTON In vitro regeneration Light emitting diodes OPTIMIZATION KINETIN
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Femtosecond laser modulated into Bessel beam by spatial light modulator for Fresnel zone plate processing
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作者 DUAN Lian ZHOU Fang +3 位作者 KONG De-jian ZHANG Fan SUN Xiao-yan DUAN Ji-an 《Journal of Central South University》 2025年第2期469-482,共14页
Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,... Femtosecond laser processing is an important machining method for micro-optical components such as Fresnel zone plate(FZP).However,the low processing efficiency of the femtosecond laser restricts its application.Here,a femtosecond laser Bessel beam is proposed to process micro-FZP,which is modulated from a Gaussian beam to a Bessel annular beam.The processing time for FZP with an outer diameter of 60μm is reduced from 30 min to 1.5 min on an important semiconductor material gallium arsenide(GaAs),which significantly improves the processing efficiency.In the modulation process,a central ablation hole that has an adverse effect on the diffraction performance is produced,and the adverse effect is eliminated by superimposing the blazed grating hologram.Meanwhile,the FZP machined by spatial light modulator(SLM)has good morphology and higher diffraction efficiency,which provides a strong guarantee for the application of micro-FZP in computed tomography and solar photovoltaic cells. 展开更多
关键词 femtosend laser Fresnel zone plate spatial light modulator Bessel beam GAAS
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Hypersonic glide vehicle trajectory prediction based on frequency enhanced channel attention and light sampling-oriented MLP network
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作者 Yuepeng Cai Xuebin Zhuang 《Defence Technology(防务技术)》 2025年第4期199-212,共14页
Hypersonic Glide Vehicles(HGVs)are advanced aircraft that can achieve extremely high speeds(generally over 5 Mach)and maneuverability within the Earth's atmosphere.HGV trajectory prediction is crucial for effectiv... Hypersonic Glide Vehicles(HGVs)are advanced aircraft that can achieve extremely high speeds(generally over 5 Mach)and maneuverability within the Earth's atmosphere.HGV trajectory prediction is crucial for effective defense planning and interception strategies.In recent years,HGV trajectory prediction methods based on deep learning have the great potential to significantly enhance prediction accuracy and efficiency.However,it's still challenging to strike a balance between improving prediction performance and reducing computation costs of the deep learning trajectory prediction models.To solve this problem,we propose a new deep learning framework(FECA-LSMN)for efficient HGV trajectory prediction.The model first uses a Frequency Enhanced Channel Attention(FECA)module to facilitate the fusion of different HGV trajectory features,and then subsequently employs a Light Sampling-oriented Multi-Layer Perceptron Network(LSMN)based on simple MLP-based structures to extract long/shortterm HGV trajectory features for accurate trajectory prediction.Also,we employ a new data normalization method called reversible instance normalization(RevIN)to enhance the prediction accuracy and training stability of the network.Compared to other popular trajectory prediction models based on LSTM,GRU and Transformer,our FECA-LSMN model achieves leading or comparable performance in terms of RMSE,MAE and MAPE metrics while demonstrating notably faster computation time.The ablation experiments show that the incorporation of the FECA module significantly improves the prediction performance of the network.The RevIN data normalization technique outperforms traditional min-max normalization as well. 展开更多
关键词 Hypersonic glide vehicle Trajectory prediction Frequency enhanced channel attention Light sampling-oriented MLP network
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LED阵列式紫外固化光源光学系统设计 被引量:26
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作者 许文海 赵欢 芦永军 《光学精密工程》 EI CAS CSCD 北大核心 2007年第7期1032-1037,共6页
设计了一种新型的LED阵列式紫外固化光源系统,该系统主要包括多路可控恒流源,紫外LED空间阵列及光学系统等,其中紫外LED空间阵列结构提高了光源的辐照度和均匀性。在分析光源结构的基础上,对其光学系统进行了设计,给出了LED空间阵列光... 设计了一种新型的LED阵列式紫外固化光源系统,该系统主要包括多路可控恒流源,紫外LED空间阵列及光学系统等,其中紫外LED空间阵列结构提高了光源的辐照度和均匀性。在分析光源结构的基础上,对其光学系统进行了设计,给出了LED空间阵列光学系统的设计方法和设计实例,并利用Light Tools光学仿真软件对其进行了模拟。结果表明:采用该光学设计方法得到的空间阵列辐照系统,其紫外辐照度可达200 mW/cm2,辐照面上光强分布均匀稳定,能够满足紫外光固化过程对光源的指标要求。 展开更多
关键词 紫外光固化 LED空间阵列 光学设计 LIGHT TOOLS
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栓皮栎体胚诱导关键影响因素研究 被引量:21
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作者 张存旭 姚增玉 赵忠 《林业科学》 EI CAS CSCD 北大核心 2005年第2期174-177,i004,共5页
Immature zygotic embryos of Quercus variabilis were as explants to induce somatic embryogenesis. Several factors influencing somatic embryogenesis have been assayed. Somatic embryos can be induced in MS and WPM basal ... Immature zygotic embryos of Quercus variabilis were as explants to induce somatic embryogenesis. Several factors influencing somatic embryogenesis have been assayed. Somatic embryos can be induced in MS and WPM basal medium, but there was more quantity, big size and high induction rate in MS medium. Induction rate was not significant cultured in light and dark condition. Zygotic embryos, collected in middle of July, gave higher rate of somatic embryogenesis than those collected on the earlier or later date. By adding 6-BA in medium individually, somatic embryogenesis appeared directly on the zygotic embryos without detectable callus. Secondary embryogenesis appeared in medium with 2,4-D individual or combined with 6-BA or TDZ. High induction frequency of 90% was achieved in MS medium supplemented with 0.5 mg·L -1 6-BA and 2,4-D, whereas the rate in hormone-free medium was only 16.7%. The genotypes of mother trees had an great impact on the inducing rate. Zygotic embryo surgery treatments were not favorable to embryogenesis. It was best to inoculate with entire zygotic embryos. The hypocotyl was a crucial part on somatic embryogenesis for Q. variabilis. 展开更多
关键词 体胚诱导 栓皮栎 with 6-BA impact was light great and the more HIGH HIGH best part The in to can MS WPM big MED CAL for mg
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人LIGHT基因的克隆及其重组腺病毒载体的构建 被引量:8
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作者 吴东 沈锋 +2 位作者 娄永华 焦炳华 吴孟超 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2002年第2期121-124,共4页
目的  克隆人LIGHT基因,构建其重组腺病毒载体,以研究LIGHT过表达与腺病毒感染对细胞生长的影响。方法用RT-PCR法从人外周血单个核细胞(PBMC)中克隆人的LIGHT全长基因。将LIGHT cDNA克隆到穿... 目的  克隆人LIGHT基因,构建其重组腺病毒载体,以研究LIGHT过表达与腺病毒感染对细胞生长的影响。方法用RT-PCR法从人外周血单个核细胞(PBMC)中克隆人的LIGHT全长基因。将LIGHT cDNA克隆到穿棱载体pAdTrack-CMV-LIGHT重组质粒中,经酶切线性化后,将重组质粒pAdTrack-CMV-LIGHT和骨架质粒pAdEasy-1,以电穿孔法共转染大肠杆菌BJ5183,获得重组腺病毒质粒。最后,将线性化的重组腺病毒质粒转染293细胞包装获得重组腺病毒,用荧光显微镜、PCR及Western blot分析LIGHT基因的表达。 结果 用RT-PCR法从人的PBMC中,扩增出723 bp的cDNA,测序证实为人LIGHT基因。荧光显微镜、PCR及Western blot证实,LIGHT重组腺病毒可感染293细胞,并在293细胞内进行有效的复制。结论成功地克隆了人LIGHT基因,并构建了其重组腺病毒载体,为进一步研究LIGHT基因的功能提供了条件。 展开更多
关键词 腺病毒 表达载体 人LIGHT基因 基因克隆 肿瘤 基因治疗
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自身免疫疾病中的LIGHT-LTβR/HVEM信号通路的研究进展 被引量:6
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作者 曹朝晖 董世访 +2 位作者 江伟凡 尹卫东 许桂莲 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2011年第12期1382-1384,共3页
LIGHT(TNFSF14)的两个主要受体:HVEM和LTβR,均为TNFR超家族成员。LIGHT-HVEM途径是重要的T细胞共刺激信号途径,而LIGHT-LTβR在改变树突细胞和间质细胞的功能方面发挥重要作用。HVEM还可与两个免疫球蛋白超基因家族成员即抑制T细胞活化... LIGHT(TNFSF14)的两个主要受体:HVEM和LTβR,均为TNFR超家族成员。LIGHT-HVEM途径是重要的T细胞共刺激信号途径,而LIGHT-LTβR在改变树突细胞和间质细胞的功能方面发挥重要作用。HVEM还可与两个免疫球蛋白超基因家族成员即抑制T细胞活化的BTLA和CD160相互作用,HVEM在刺激和抑制信号之间充当一种分子开关。人和实验动物模型研究显示LIGHT-LTβR/HVEM途径在自身免疫疾病的炎症反应和病理发生中起重要的免疫调节作用。因此,在免疫相关疾病的免疫干预治疗中,LIGHT是一种良好的潜在靶标。本文就LIGHT-LTβR/HVEM途径在免疫相关疾病中作用的最新研究进展做一综述。 展开更多
关键词 LIGHT T细胞 自身免疫疾病
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LIGHT-Fc基因转染对食管癌细胞株Eca109抑制作用的初步研究 被引量:5
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作者 熊刚 杨康 白云 《第三军医大学学报》 CAS CSCD 北大核心 2004年第8期686-689,共4页
目的 探讨LIGHT对人食管癌细胞的体外抑制效应。方法 以DOTAP脂质体介导LIGHT Fc基因转染人食管癌细胞株Eca10 9,通过绘制细胞生长曲线及MTT比色法观察LIGHT Fc转染对Eca10 9细胞生长的影响 ,用RT PCR法检测LIGHT受体在Eca10 9细胞上... 目的 探讨LIGHT对人食管癌细胞的体外抑制效应。方法 以DOTAP脂质体介导LIGHT Fc基因转染人食管癌细胞株Eca10 9,通过绘制细胞生长曲线及MTT比色法观察LIGHT Fc转染对Eca10 9细胞生长的影响 ,用RT PCR法检测LIGHT受体在Eca10 9细胞上的表达。结果 LIGHT Fc基因的表达可以抑制Eca10 9细胞的生长。在低血清培养时 ,Eca10 9 LIGHT细胞的生长曲线较对照组明显降低 ;MTT比色显示Eca10 9 LIGHT的细胞活力与对照组相比有显著性差异 (P<0 .0 5 )。结论 LIGHT Fc基因转染对人食管癌Eca10 9细胞具有体外抑制作用 。 展开更多
关键词 LIGHT 转染 ECA109细胞 基因治疗
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新时代科技期刊品牌化、集群化发展探讨--以Light品牌期刊集群为例 被引量:17
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作者 张莹 白雨虹 《出版广角》 CSSCI 北大核心 2022年第19期25-30,共6页
Light品牌期刊集群通过借鉴国内外典型出版机构的管理机制和办刊模式,立足国内,放眼国际,在创新管理机制、优化学科布局、组约顶尖成果、开创特色栏目、打造科技媒体、创新服务模式等方面进行探索与实践,走出了一条具有中国特色和国际... Light品牌期刊集群通过借鉴国内外典型出版机构的管理机制和办刊模式,立足国内,放眼国际,在创新管理机制、优化学科布局、组约顶尖成果、开创特色栏目、打造科技媒体、创新服务模式等方面进行探索与实践,走出了一条具有中国特色和国际影响力的品牌化、集群化发展道路。面对新时代品牌化、集群化发展面临的困难和挑战,我国科技期刊应从品牌刊群建设、数字平台建设和人才队伍建设方面开拓创新,走出一条具有中国特色和国际影响力的品牌刊群之路,以实现我国科技期刊高质量、跨越式发展。 展开更多
关键词 品牌化 集群化 集约协同 融合出版 Light期刊集群
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基于多尺度变换的动态光散射粒径反演范围的自适应调整 被引量:5
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作者 王雅静 申晋 +2 位作者 郑刚 孙贤明 刘伟 《强激光与粒子束》 EI CAS CSCD 北大核心 2010年第12期2979-2983,共5页
通过多尺度变换实现了反演范围的自适应调整,使其更接近真实范围。分别采用反演范围固定算法与自适应算法对200~600 nm单峰和200~900 nm双峰分布颗粒的模拟相关函数进行了反演,结果表明:自适应算法的结果更接近理论分布,抗干扰能力更... 通过多尺度变换实现了反演范围的自适应调整,使其更接近真实范围。分别采用反演范围固定算法与自适应算法对200~600 nm单峰和200~900 nm双峰分布颗粒的模拟相关函数进行了反演,结果表明:自适应算法的结果更接近理论分布,抗干扰能力更强。相对于固定算法,单峰分布颗粒最多可缩小峰值误差4.73%,缩小峰宽误差185 nm。双峰分布颗粒在0~0.001噪声水平时,峰值误差分别小于11.33%,12.45%,峰宽误差分别小于35,160 nm,而固定算法在噪声水平大于0.000 1时,难以得到合理的反演结果。反演范围自适应调整方法能够有效优化粒径反演结果。 展开更多
关键词 多尺度变换 动态光散射 粒径 反演 自适应调整 based scattering particle light dynamic 自适应算法 噪声水平 峰值误差 双峰分布 结果 误差分 颗粒 固定 抗干扰能力 相关函数 理论分布
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非接触手成像系统图像采集光源的研究 被引量:4
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作者 苑玮琦 杨冰 《激光与红外》 CAS CSCD 北大核心 2014年第7期783-787,共5页
研究了基于TMS320DM642 DSP芯片的非接触多光谱手识别装置中的光源。在整个识别装置中,光源占有举足轻重的地位,合理准确的光源能够采集到清晰的手部信息图像,并有利于提高用户身份识别的准确率。基于此目的搭建了以恒流源控制芯片、LE... 研究了基于TMS320DM642 DSP芯片的非接触多光谱手识别装置中的光源。在整个识别装置中,光源占有举足轻重的地位,合理准确的光源能够采集到清晰的手部信息图像,并有利于提高用户身份识别的准确率。基于此目的搭建了以恒流源控制芯片、LED为主要器件的多光谱光源控制系统:恒流源芯片要驱动采集手掌掌纹信息的470 nm的可见蓝光LED和采集手掌静脉、掌形信息的850 nm近红外光LED;且可实现一次拍摄并获取高质量的三模态信息(掌纹、手掌静脉及掌形)的图像;并利用Light Tools软件对该光源进行了辅助验证。该设计不但解决了在获取手部三模态信息时需要转换光源的问题,而且还为多模态手部识别奠定了数据基础和实验环境。 展开更多
关键词 三模态 多光谱 光源 LIGHT TOOLS
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一个输电线系统净空排查算法的优化过程 被引量:2
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作者 游安清 韩晓言 +1 位作者 潘旭东 贺喜 《计算机工程与应用》 CSCD 2014年第17期259-262,266,共5页
针对激光雷达扫描得到的输电线路三维点云数据,在对象分类的基础上,设计一个全自动的净空排查算法,以确定输电线路与周围地物是否有过于接近的情况。由于净空排查的基本算法相当耗时,故采用了包围盒、循环调整、降维、多分辨率、并行运... 针对激光雷达扫描得到的输电线路三维点云数据,在对象分类的基础上,设计一个全自动的净空排查算法,以确定输电线路与周围地物是否有过于接近的情况。由于净空排查的基本算法相当耗时,故采用了包围盒、循环调整、降维、多分辨率、并行运算等措施,对基本算法作了7级优化,使算法速度提高超过20 000倍,最终达到亚秒级的耗时。 展开更多
关键词 激光雷达 三维点云 输电线 距离排查 Light Detection And Ranging(LiDAR)
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徕卡机载激光雷达的数据获取与处理 被引量:8
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作者 马洪超 姚春静 《测绘通报》 CSCD 北大核心 2008年第10期70-71,共2页
关键词 机载激光雷达 数据获取 激光雷达技术 徕卡 激光测距技术 三维坐标 点云数据 LIGHT
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人LIGHT胞外段基因的克隆及在大肠杆菌中的表达 被引量:1
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作者 郝文丽 江文正 +2 位作者 闻洁君 樊燕 钱旻 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2009年第12期1076-1078,共3页
目的:构建人LIGHT胞外段基因的原核表达载体,并在大肠杆菌中诱导表达。方法:从人外周血单核细胞来源的未成熟树突状细胞中提取总RNA,通过RT-PCR得到LIGHT胞外段基因,并将其克隆至pET32a(+)原核表达载体中,经双酶切鉴定及序列测定后的重... 目的:构建人LIGHT胞外段基因的原核表达载体,并在大肠杆菌中诱导表达。方法:从人外周血单核细胞来源的未成熟树突状细胞中提取总RNA,通过RT-PCR得到LIGHT胞外段基因,并将其克隆至pET32a(+)原核表达载体中,经双酶切鉴定及序列测定后的重组质粒转化入E.coli BL21,IPTG诱导表达目的蛋白,并用SDS-PAGE和Western blot进行检测。结果:RT-PCR扩增出了大小为543bp的LIGHT胞外段基因,经测序证明序列正确。SDS-PAGE和Western blot分析证实重组质粒可表达出Mr约为41000的蛋白。结论:成功地克隆了人LIGHT胞外段基因并在大肠杆菌中进行了表达为进一步研究LIGHT的功能打下了基础。 展开更多
关键词 LIGHT 基因克隆 原核表达 大肠杆菌
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