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基于2024版C-NCAP FRB工况的某乘用车平台车型结构耐撞性优化
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作者 虞科炯 周枫 《上海汽车》 2024年第5期16-22,共7页
正面100%重叠刚性壁障(FRB)工况是考核整车被动安全性能的重要测试之一。针对2024版C-NCAP中的FRB工况,对某乘用车平台的两款不同车型开展结构耐撞性研究。通过分析Base状态的变形模式、加速度响应曲线及结构入侵指标等结果,给出了耐撞... 正面100%重叠刚性壁障(FRB)工况是考核整车被动安全性能的重要测试之一。针对2024版C-NCAP中的FRB工况,对某乘用车平台的两款不同车型开展结构耐撞性研究。通过分析Base状态的变形模式、加速度响应曲线及结构入侵指标等结果,给出了耐撞性优化方向。从区分设计前端吸能盒、规划能量吸收与传递路径、引导结构产生理想变形模式3个方面,提出了具体的优化方案。结果表明:优化后PHEV和ICE车型的有效加速度均明显降低,结构侵入值未见超标,能够较好地满足2024版C-NCAP五星评价要求。 展开更多
关键词 C-NCAP规程 正面碰撞 FRB工况 耐撞性 结构优化
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Data from Twenty-Three FRB’s Confirm the Universe Is Static and Not Expanding
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作者 Lyndon Errol Ashmore 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1152-1177,共26页
Fast Radio Bursts from far away galaxies have travelled through the IGM and provide a tool to study its composition. Presently there are 23 FRB’s whose host galaxies have been identified and the redshift found. This ... Fast Radio Bursts from far away galaxies have travelled through the IGM and provide a tool to study its composition. Presently there are 23 FRB’s whose host galaxies have been identified and the redshift found. This gives us the opportunity to test Dispersion Measure versus redshift predictions made by two models. The Macquart relation for an expanding Universe and the New Tired Light relationship in a static universe. In New Tired Light, redshifts are produced when a photon is absorbed and re-emitted by the electrons in the IGM which recoil on both occasions. Some of the energy of the photon has been transferred to the kinetic energy of the recoiling electron. The photon has less energy, a lower frequency and a longer wavelength. It has been redshifted. Since dispersion is due to an interaction between radio signals and these same electrons one would expect a direct relationship between DM and redshift in the New Tired light model. The relation is DM=(mec/2hre)ln(1+z)and contains no adjustable parameters—just a combination of universal constants related to the electron and photon. Notice that the relation is independent of the electron number density ne since a change in ne affects both the DM and redshift equally. A graph of DM versus ln(1 + z) will be a straight line of gradient (mec/2hre)and, using SI units, substituting for the constants gives 7.318 × 1025 m−2. Using the data from the 23 well localized FRB’s, with the weighting of the DM’s for expansion removed (so that the data corresponds to a static universe), a graph of DM versus ln(1 + z) has a gradient of 6.7 × 1025 m−2—9% below the predicted (mec/2hre). The Macquart relation involves highly processed data and adjustable parameters to allow for “dark energy” and “dark matter” (neither of which has yet been found) and can be reduced to DM = 850z (in units of pc∙cm−3). Using the data from this set of localized FRB’s gives a trendline with gradient 1.10 × 103 pc∙cm−3—almost 30% higher than that predicted in an expanding universe model. The FRB data clearly comes down in favour of a static universe rather than an expanding one. Combining the DM-z relationship for the 23 well localized FRB’s, with the Hubble diagram, drawn using the NED-D compilation of redshift independent extragalactic distances, produces a value of “ne” the mean electron number density of the IGM, of ne=0.48 m−3close to the value ne=0.5 m−3, long since predicted by NTL. 展开更多
关键词 REDSHIFT Dispersion Measure Fast Radio Bursts FRB’s Tired Light Static Universe IGM
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基于PCT模型的快速射电暴搜索算法
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作者 李俊霖 《信息技术与信息化》 2024年第4期93-96,共4页
快速射电暴(FRB)是一种神秘的天文现象,在射电天文学领域,FRB的研究对于理解宇宙中的极端物理过程和天体演化机制具有重要意义。针对现有面向真实FRB信号的搜寻算法存在资源耗费大、搜寻效率低等问题,提出了一种基于小波卷积与Former结... 快速射电暴(FRB)是一种神秘的天文现象,在射电天文学领域,FRB的研究对于理解宇宙中的极端物理过程和天体演化机制具有重要意义。针对现有面向真实FRB信号的搜寻算法存在资源耗费大、搜寻效率低等问题,提出了一种基于小波卷积与Former结构的搜索算法。采用图像金字塔构建不同尺寸下的图像特征,利用小波卷积特征提取器和Former特征提取器分别对不同尺寸的图像特征进行特征提取,随后使用特征采样注意力机制对不同特征提取器提取的特征结果进行特征融合,以判断当前信号帧图像中是否存在快速射电暴信号。实验结果表明,所提出的方法能减少时间开销,提高分类准确率。在公开的真实数据集上进行了迁移训练,将算法应用到真实FRB信号的搜寻中,测试结果表明,算法对真实FRB信号搜寻的准确率达到了0.996,F1指标达到了0.986,代码和实验公开在https://github.com/aoxipo/PCT网站上。 展开更多
关键词 ATTENTION TRANSFORMER 深度学习 FRB搜索
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重复快速射电暴FRB 20180916B的周期性行为
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作者 林一清 黄辉祥 程再军 《厦门理工学院学报》 2024年第3期31-35,共5页
收集2018年9月16日到2022年12月15日重复快速射电暴(fast radio bursts,FRBs)FRB20180916B的127次爆发,分析这个暴的行为,验证它的周期性。通过得到FRB 20180916B周期性暴的周期为16.32 d,支持了FRB 20180916B最早被认定的周期性暴的周... 收集2018年9月16日到2022年12月15日重复快速射电暴(fast radio bursts,FRBs)FRB20180916B的127次爆发,分析这个暴的行为,验证它的周期性。通过得到FRB 20180916B周期性暴的周期为16.32 d,支持了FRB 20180916B最早被认定的周期性暴的周期为16.35 d的结论。结果表明,不管FRB20180916B的物理起源是由爆发本身引起的,还是由外部因素引起的,都可能是一个周期性的机制起源。 展开更多
关键词 快速射电暴 FRB 20180916B 周期搜索 射电暂现源 高能天体物理
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PAC模型的迭代最小二乘法估计——以居民消费为例
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作者 何学渊 《中文科技期刊数据库(全文版)经济管理》 2024年第3期0077-0082,共6页
PAC(polynomial adjustment costs)模型的一个重要特征是明确地将对未来事件的预期与由于调整成本而延迟的预期响应分开。这一特征要求利用PAC模型与非结构化的VAR组合预测的预期项估计出的动态调整模型与所利用的PAC模型本身必须一致... PAC(polynomial adjustment costs)模型的一个重要特征是明确地将对未来事件的预期与由于调整成本而延迟的预期响应分开。这一特征要求利用PAC模型与非结构化的VAR组合预测的预期项估计出的动态调整模型与所利用的PAC模型本身必须一致。本文通过开发以E-QNEWTON算法为核心的迭代的最小二乘法,估计出了满足该一致性条件的PAC模型。将其与简化方法估计的模型进行对比显示:二者所估计的流动性约束家庭占比相似;前者估计的滞后项对消费调整的影响小于后者;它们的预测性能差异不大,前者的预测性能略微劣于后者。 展开更多
关键词 FRB/US模型 PAC模型 理性预期 迭代的最小二乘法
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基于ROACH2的脉冲星终端研制进展 被引量:4
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作者 裴鑫 李健 +2 位作者 袁建平 温志刚 陈卯蒸 《天文学进展》 CSCD 北大核心 2017年第2期244-254,共11页
脉冲星观测研究一直是新疆天文台的主要研究方向,未来建设的新疆110 m口径全可动射电望远镜(简称QTT)也将其作为主要研究方向之一。南山25 m射电望远镜当前使用的脉冲星单脉冲观测终端AFB已使用近20年,系统老化严重,为升级现有单脉冲观... 脉冲星观测研究一直是新疆天文台的主要研究方向,未来建设的新疆110 m口径全可动射电望远镜(简称QTT)也将其作为主要研究方向之一。南山25 m射电望远镜当前使用的脉冲星单脉冲观测终端AFB已使用近20年,系统老化严重,为升级现有单脉冲观测系统,也为QTT的终端设计做预研,基于ROACH2研制了一套脉冲星观测系统。该系统采用氢钟与GPS时间同步以提供秒起始信号,对采样时钟计数并打入数据帧以获取精准时间间隔,两者合成即可获得精确时间信息;采用共享内存缓冲区,使数据在多进程间共享实现并行实时处理。该系统可用于脉冲星单脉冲或到达时间观测,也可用于脉冲星、RRAT或FRB等搜寻。已在南山进行单脉冲、长时间折叠、FRB实时搜寻等观测试验,试验数据表明该终端准确、稳定、可靠,已达到投入观测使用的要求。 展开更多
关键词 观测终端 ROACH2 脉冲星观测 FRB
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Investigation of Induced Unbalance Magnitude on Dynamic Characteristics of High-speed Turbocharger with Floating Ring Bearings 被引量:9
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作者 Guang-Fu Bin Yuan Huang +2 位作者 Shuai-Ping Guo Xue-Jun Li Gang Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第5期99-109,共11页
Due to operational wear and uneven carbon absorption in compressor and turbine wheels, the unbalance(me) vibration is induced and could lead to sub?synchronous vibration accidents for high?speed turbocharger(TC). Ther... Due to operational wear and uneven carbon absorption in compressor and turbine wheels, the unbalance(me) vibration is induced and could lead to sub?synchronous vibration accidents for high?speed turbocharger(TC). There are very few research works that focus on the magnitude e ects on such induced unbalance vibration. In this paper, a finite element model(FEM) is developed to characterize a realistic automotive TC rotor with floating ring bearings(FRBs). The nonlinear dynamic responses of the TC rotor system with di erent levels of induced unbalance magni?tude in compressor and turbine wheels are calculated. From the results of waterfall and response spectral intensity plots, the bifurcation and instability phenomena depend on unbalance magnitude during the startup of TC. The sub?synchronous component 0.12× caused rotor unstable is the dominant frequency for small induced unbalance. The nonlinear e ects of induced unbalance in the turbine wheel is obvious stronger than the compressor wheel. As the unbalance magnitude increases from 0.05 gbration 1·mm to 0.2 g·mm, the vibration component changes from mainly 0.12× to synchronous vi×. When unbalance increases continuously, the rotor vibration response amplitude is rapidly growing and the 1× caused by the large unbalance excitation becomes the dominant frequency. A suitable un?balance magnitude of turbine wheel and compressor wheel for the high?speed TC rotor with FRBs is proposed: the value of induced un?balance magnitude should be kept around 0.2 g·mm. 展开更多
关键词 High?speed TC with frbs Induced unbalance magnitude Nonlinear dynamic response Sub?synchronous vibration Stability
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蚁群优化算法中的模糊规则学习问题 被引量:1
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作者 戴文志 钟珀辰 张祥 《电子技术与软件工程》 2013年第18期76-78,共3页
本文通过对蚁群优化算法原理及基于模糊规则系统的原理性的介绍,旨在提出一种能够指导应用蚁群优化算法于复杂系统中模糊规则学习的方法性综述。相信在复杂系统的未来发展中,蚁群优化系统必有其一席之地。
关键词 蚁群优化算法 ACO 基于模糊规则的系统 frbs ACO-FRL
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公众预期在美联储FRB/US模型中的显性刻画及其对我国货币政策的启示
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作者 徐亚平 徐韬 兰茹佳 《金融理论与实践》 CSSCI 北大核心 2012年第9期30-34,共5页
美联储FRB/US模型基于信息的不同假设,分别采用了与模型相一致的预期和附加前瞻性政策变量的VAR预期,对预期进行了显性的刻画,并借助现代计算技术的发展,对预期进行了明确的求解,进而基于预期形成的各种假设条件对货币政策效应进行模拟... 美联储FRB/US模型基于信息的不同假设,分别采用了与模型相一致的预期和附加前瞻性政策变量的VAR预期,对预期进行了显性的刻画,并借助现代计算技术的发展,对预期进行了明确的求解,进而基于预期形成的各种假设条件对货币政策效应进行模拟分析。 展开更多
关键词 公众预期 FRB/US模型 货币政策
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基于雷帕霉素与FRB结合的蛋白质间相互作用的相关技术
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作者 李芹芹 史道华 杨牛牛 《生物技术通报》 CAS CSCD 北大核心 2011年第9期44-47,共4页
FKBP12-rapamycin复合物的结合位点(FKBP12-rapamycin binding,FRB)为雷帕霉素(rapamycin,RAP)与哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)结合的结构域,基于RAP介导FK506结合蛋白12(12 kD FK506-bin-ging protein,F... FKBP12-rapamycin复合物的结合位点(FKBP12-rapamycin binding,FRB)为雷帕霉素(rapamycin,RAP)与哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)结合的结构域,基于RAP介导FK506结合蛋白12(12 kD FK506-bin-ging protein,FKBP12)与FRB蛋白质相互作用相关研究技术的发展与应用,使人们对小分子介导的蛋白质相互作用有了更多的认识。就研究RAP作用于FRB域及研究FKBP12-RAP-FRB三元复合物形成的相关技术作一综述,为确认新的mTOR抑制剂的作用机制及认识其他蛋白质间相互作用提供参考。 展开更多
关键词 FRB域 雷帕霉素 蛋白质间相互作用 技术
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FAST Observations of an Extremely Active Episode of FRB 20201124A:Ⅰ.Burst Morphology 被引量:2
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作者 D.J.Zhou J.L.Han +16 位作者 B.Zhang K.J.Lee W.W.Zhu D.Li W.C.Jing W.-Y.Wang Y.K.Zhang J.C.Jiang J.R Niu R Luo H.Xu C.F.Zhang B.J.Wang J.W.Xu P.Wang Z.L.Yang Y.Feng 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第12期54-69,共16页
We report the properties of more than 600 bursts(including cluster-bursts)detected from the repeating fast radio burst(FRB)source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio Telescope during an ... We report the properties of more than 600 bursts(including cluster-bursts)detected from the repeating fast radio burst(FRB)source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio Telescope during an extremely active episode on UTC 2021 September 25–28,in a series of four papers.The observations were carried out in the band of 1.0–1.5 GHz by using the center beam of the L-band 19-beam receiver.We monitored the source in sixteen1 hr sessions and one 3 hr session spanning 23 days.All the bursts were detected during the first four days.In this first paper of the series,we perform a detailed morphological study of 624 bursts using the two-dimensional frequencytime“waterfall”plots,with a burst(or cluster-burst)defined as an emission episode during which the adjacent emission peaks have a separation shorter than 400 ms.The duration of a burst is therefore always longer than 1 ms,with the longest up to more than 120 ms.The emission spectra of the sub-bursts are typically narrow within the observing band with a characteristic width of~277 MHz.The center frequency distribution has a dominant peak at about 1091.9 MHz and a secondary weak peak around 1327.9 MHz.Most bursts show a frequencydownwarddrifting pattern.Based on the drifting patterns,we classify the bursts into five main categories:downward drifting(263)bursts,upward drifting(3)bursts,complex(203),no drifting(35)bursts,and no evidence for drifting(121)bursts.Subtypes are introduced based on the emission frequency range in the band(low,middle,high and wide)as well as the number of components in one burst(1,2,or multiple).We measured a varying scintillation bandwidth from about 0.5 MHz at 1.0 GHz to 1.4 MHz at 1.5 GHz with a spectral index of 3.0. 展开更多
关键词 (stars:)pulsars:general Physical Data and Processes stars:individual(FRB 20201124A)
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FAST Observations of an Extremely Active Episode of FRB 20201124A.Ⅱ.Energy Distribution 被引量:2
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作者 Yong-Kun Zhang Pei Wang +17 位作者 Yi Feng Bing Zhang Di Li Chao-Wei Tsai Chen-Hui Niu Rui Luo Ju-Mei Yao Wei-Wei Zhu Jin-Lin Han Ke-Jia Lee De-Jiang Zhou Jia-Rui Niu Jin-Chen Jiang Wei-Yang Wang Chun-Feng Zhang Heng Xu Bo-Jun Wang Jiang-Wei Xu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第12期70-80,共11页
We report the properties of more than 800 bursts detected from the repeating fast radio burst(FRB)source FRB20201124A with the Five-hundred-meter Aperture Spherical radio Telescope(FAST)during an extremely active epis... We report the properties of more than 800 bursts detected from the repeating fast radio burst(FRB)source FRB20201124A with the Five-hundred-meter Aperture Spherical radio Telescope(FAST)during an extremely active episode on UTC 2021 September 25–28 in a series of four papers.In this second paper of the series,we study the energy distribution of 881 bursts(defined as significant signals separated by dips down to the noise level)detected in the first four days of our 19 hr observational campaign spanning 17 days.The event rate initially increased exponentially but the source activity stopped within 24 hr after the 4th day.The detection of 542 bursts in one hour during the fourth day marked the highest event rate detected from one single FRB source so far.The bursts have complex structures in the time-frequency space.We find a double-peak distribution of the waiting time,which can be modeled with two log-normal functions peaking at 51.22 ms and 10.05 s,respectively.Compared with the emission from a previous active episode of the source detected with FAST,the second distribution peak time is smaller,suggesting that this peak is defined by the activity level of the source.We calculate the isotropic energy of the bursts using both a partial bandwidth and a full bandwidth and find that the energy distribution is not significantly changed.We find that an exponentially connected broken-power law function can fit the cumulative burst energy distribution well,with the lower and higher-energy indices being-1.22±0.01 and-4.27±0.23,respectively.Assuming a radio radiative efficiency ofη_(r)=10^(-4),the total isotropic energy of the bursts released during the four days when the source was active is already 3.9×10^(46)erg,exceeding~23%of the available magnetar dipolar magnetic energy.This challenges the magnetar models which invoke an inefficient radio emission(e.g.,synchrotron maser models). 展开更多
关键词 (stars:)pulsars:general stars:individual(FRB 20201124A) methods:data analysis
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Burst Astrophysics 被引量:1
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作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 2017年第2期157-166,共10页
This article proposes an explanation for Fast Radio Bursts (FRBs) and Gamma Ray Bursts (GRBs) through the frames of Hypersphere World-Universe Model (WUM). WUM predicts that the concentration of protons and electrons ... This article proposes an explanation for Fast Radio Bursts (FRBs) and Gamma Ray Bursts (GRBs) through the frames of Hypersphere World-Universe Model (WUM). WUM predicts that the concentration of protons and electrons in Intergalactic Plasma decreases inversely proportional to time and in present epoch equals to . The energy density of Intergalactic Plasma relative to the critical energy density equals to . Time delay of FRBs is calculated through these characteristics. A number of experimental results, including the redshift for FRB 150418, remarkable brightness for FRB 150807, and transient gamma-ray counterpart for FRB 131104 are explained. The distance to FRB 150807 object is predicted to be ~800 Mpc. WUM holds that all macroobjects (galaxies, stars, and planets) contain a core composed of Dark Matter Particles. GRBs are explained as a sum of contributions of multicomponent dark matter annihilation. The spectra of such bursts depend on the composition of the Cores. 展开更多
关键词 HYPERSPHERE World-Universe Model Medium of the World Intergalactic Plasma Macroobjects Structure Dark Matter Particles GAMMA-RAY BURSTS Fast Radio BURSTS FRB Time Delay
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乘用车前端车体架构规划 被引量:1
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作者 杨国勇 杨金秀 +2 位作者 罗培锋 饶俊威 黄涌 《汽车文摘》 2021年第5期39-43,共5页
随着中国新车评价规程C-NCAP 2021版和中国保险汽车安全指数C-IASI 2018的正式实施,市场对乘用车的全正面刚性壁障(Front Rigid Barrier, FRB)、50%移动渐进可变形壁障(Moving Progressive Deformable Barrier, MPDB)、25%小偏置刚性壁... 随着中国新车评价规程C-NCAP 2021版和中国保险汽车安全指数C-IASI 2018的正式实施,市场对乘用车的全正面刚性壁障(Front Rigid Barrier, FRB)、50%移动渐进可变形壁障(Moving Progressive Deformable Barrier, MPDB)、25%小偏置刚性壁障(Small Overlap Rigid Barrier, SORB)和行人保护有了严格的检测标准。为此,汽车厂商和汽车设计研究机构都在寻找各方面(性能/质量/成本/空间/整车尺寸等)相对均衡的方案。根据碰撞的方向和位置的不同,车体可以分为前端、后端和侧端,针对乘用车前端碰撞密切相关的前端车体架构,在深入研究国内、国外汽车公司和研究机构的做法及建议的基础上,结合实车的仿真和试验,进行分析、探讨。 展开更多
关键词 汽车安全性 车体架构 正碰 对碰 小偏置碰 FRB SORB MPDB
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发酵米糠具有抗压力和抗疲劳作用
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《四川食品与发酵》 2003年第2期55-55,共1页
关键词 发酵米糠 抗压力 抗疲劳作用 FRB热水提取物 动物实验
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Erratum to “Data from Twenty-Three FRB’s Confirm the Universe Is Static and Not Expanding”, [Journal of High Energy Physics, Gravitation and Cosmology 2024, 10, 1152-1177]
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作者 Lyndon Errol Ashmore 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期165-167,共3页
Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting... Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting with these self-same electrons and so, one would expect a direct relationship between the DM of an FRB and the redshift of the host galaxy. However, workers in this field assume expansion and weight the DM by dividing it by the scale factor (1 + z) to allow for expansion. Once this weighting is removed, it was predicted back in 2016 (when the first FRB was localized) and later presented at a conference and published in the proceedings that, as more FRB’s were localized, a graph of DM versus ln(1 + z) would be a straight line of gradient (mec/2hre) or 7.32 × 1025 m−2 in SI units. The original paper had twenty-four data points but this has risen significantly to sixty-four useable FRB’s and so this corrigendum updates that paper so that all sixty-four are used. The data give a straight-line graph of gradient 7.12 × 1025 m−2, a difference of 3% from (mec/2hre) predicted nine years earlier. 展开更多
关键词 Redshift Dispersion Measure Fast Radio Bursts FRB’s Tired Light Static Universe IGM
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高温环境下耐火钢Q235FRB力学性能试验研究
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作者 张泽宇 曾立静 +4 位作者 李红旭 蒋录珍 王月栋 侯兆新 李伟男 《钢结构(中英文)》 2024年第10期111-118,共8页
为了研究耐火钢在高温环境下的力学性能,采用高温稳态试验方法进行耐火钢Q235FRB标准件的拉伸试验。基于试验结果,得到了不同温度条件下耐火钢Q235FRB的应力-应变曲线,据此给出了高温下耐火钢各项力学性能参数指标(包括弹性模量、屈服... 为了研究耐火钢在高温环境下的力学性能,采用高温稳态试验方法进行耐火钢Q235FRB标准件的拉伸试验。基于试验结果,得到了不同温度条件下耐火钢Q235FRB的应力-应变曲线,据此给出了高温下耐火钢各项力学性能参数指标(包括弹性模量、屈服强度、抗拉强度)的折减系数。研究结果表明,耐火钢Q235FRB的强度指标(包括弹性模量、屈服强度、抗拉强度)与温度基本呈负相关关系,并提出了对应计算模型。当温度达到400℃时,强度指标劣化速率加快,温度升至800℃时,强度指标基本为常温性能的10%。耐火钢Q235FRB的变形指标(极限伸长率)基本随着温度的升高呈先减小后增大的趋势。通过对比分析,耐火钢Q235FRB的力学性能和耐高温性能优于同等级普通钢,具有广泛应用前景。 展开更多
关键词 耐火钢Q235FRB 高温环境 试验研究 力学性能
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Scintillation Arc from FRB 20220912A
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作者 Zi-Wei Wu Robert AMain +21 位作者 Wei-Wei Zhu Bing Zhang Peng Jiang Jia-Rui Niu Jin-Lin Han Di Li Ke-Jia Lee Dong-Zi Li Yuan-Pei Yang Fa-Yin Wang Rui Luo Pei Wang Chen-Hui Niu Heng Xu Bo-Jun Wang Wei-Yang Wang Yong-Kun Zhang Yi Feng De-Jiang Zhou Yong-Hua Xu Can-Min Deng Yu-Hao Zhu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第1期134-142,共9页
We present the interstellar scintillation analysis of fast radio burst(FRB)20220912A during its extremely active episode in 2022using data from the Five-hundred-meter Aperture Spherical Radio Telescope(FAST).We detect... We present the interstellar scintillation analysis of fast radio burst(FRB)20220912A during its extremely active episode in 2022using data from the Five-hundred-meter Aperture Spherical Radio Telescope(FAST).We detect a scintillation arc in the FRB’s secondary spectrum,which describes the power in terms of the scattered FRB signals’time delay and Doppler shift.The arc indicates that the scintillation is caused by a highly localized region.Our analysis favors a Milky Way origin of the ionized interstellar medium(IISM)for the localized scattering medium but cannot rule out a host galaxy origin.We present our method for detecting the scintillation arc,which can be applied generally to sources with irregularly spaced bursts or pulses.These methods could help shed light on the complex interstellar environment surrounding the FRBs and in our Galaxy. 展开更多
关键词 fast radio burst scintillation FRB 20220912A
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嵌合腺病毒Ad5F35-FLAG-3NLS-FRB的构建与鉴定 被引量:3
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作者 高淼 黄峥兰 +2 位作者 李千音 钟梁 冯文莉 《中国生物制品学杂志》 CAS CSCD 2012年第10期1276-1280,共5页
目的构建携带FLAG-3NLS-FRB*融合基因的嵌合腺病毒,并检测其在AD-293细胞中的表达。方法将FLAG标记的3段核定位信号(FLAG-3NLS)与突变修饰的雷帕霉素靶FRB结构域(FRB*)基因通过重叠PCR技术拼接成FLAG-3NLS-FRB*,定向克隆至腺病毒穿梭载... 目的构建携带FLAG-3NLS-FRB*融合基因的嵌合腺病毒,并检测其在AD-293细胞中的表达。方法将FLAG标记的3段核定位信号(FLAG-3NLS)与突变修饰的雷帕霉素靶FRB结构域(FRB*)基因通过重叠PCR技术拼接成FLAG-3NLS-FRB*,定向克隆至腺病毒穿梭载体pAdTrack-CMV中,测序鉴定后,与腺病毒骨架质粒pAd5F35在大肠杆菌BJ5183中同源重组,获得嵌合腺病毒Ad5F35-FLAG-3NLS-FRB*,感染AD-293细胞进行包装、扩增。采用基因转移单位(Gene transfer unit,GTU)法测定病毒滴度;RT-PCR及Western blot检测FLAG-3NLS-FRB*在AD-293细胞中的转录及表达。结果腺病毒穿梭质粒pAdTrack-CMV-FLAG-3NLS-FRB*经PCR、双酶切及测序鉴定证明构建正确;FLAG-3NLS-FRB*正确克隆至腺病毒骨架质粒中;在AD-293细胞中包装、扩增获得了高滴度的嵌合腺病毒Ad5F35-FLAG-3NLS-FRB*,病毒滴度为2.0×1013GTU/ml;嵌合腺病毒感染AD-293细胞后36 h,在细胞中可检测到FLAG-3NLS-FRB*基因的转录和蛋白的表达。结论成功构建了高滴度的嵌合腺病毒Ad5F35-FLAG-3NLS-FRB*,并在AD-293细胞中成功表达了FLAG-3NLS-FRB*融合蛋白。 展开更多
关键词 嵌合腺病毒 同源重组 核定位信号 FRB
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