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GeV γ射线噪Blazars的谱能分布及不同子类之间的联系
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作者 丁世学 《襄樊学院学报》 2006年第5期19-22,共4页
文章通过引入一个新内禀复合谱指数αγxγ=αxγ?αγ后,给出25个blazars的复合谱指数αxox和αγxγ的分布,分析研究表明三类blazars天体在高能辐射的谱能分布尽管存在差别但在谱性质上表现出明显的连续性.XBLs(HBLs)和FSRQs位于不同... 文章通过引入一个新内禀复合谱指数αγxγ=αxγ?αγ后,给出25个blazars的复合谱指数αxox和αγxγ的分布,分析研究表明三类blazars天体在高能辐射的谱能分布尽管存在差别但在谱性质上表现出明显的连续性.XBLs(HBLs)和FSRQs位于不同的区域而RBLs(LBLs)位于中间态.这一结论与Sambruna等人的低能辐射情况下双色图的结论是一致的. 展开更多
关键词 活动星系核 BLAZARS 谱能分布
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XBLs和平谱射电类星体间峰值频率与光谱指数的相关性分析 被引量:2
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作者 丁世学 《华中师范大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第4期430-432,440,共4页
对Fossati等人的研究中所给出的Blazars样本分别计算同步辐射峰值频率及射电到X射线的宽波段光谱指数;在此基础上研究了XBLs和平谱射电类星体间的峰值频率与光谱指数的相关性质.结果表明:两者之间存在着较强的相关性质,XBLs和平谱射电... 对Fossati等人的研究中所给出的Blazars样本分别计算同步辐射峰值频率及射电到X射线的宽波段光谱指数;在此基础上研究了XBLs和平谱射电类星体间的峰值频率与光谱指数的相关性质.结果表明:两者之间存在着较强的相关性质,XBLs和平谱射电类星体位于不同的区域,满足αrx<0.75和αrx>0.75.这意味着它们之间的能谱分布形状是有差异的,因而有助于我们了解其内部辐射机制. 展开更多
关键词 BLAZARS 峰值频率 谱能分布 非热辐射
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XBLs和RBLs间的光度与宽波段谱指数的相关性分析 被引量:1
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作者 丁世学 《襄樊学院学报》 2004年第5期10-14,共5页
对Fossati等人的研究中所给出的Blazar样本分别计算从射电到X射线波段的光度、宽波段光谱指数. 在此基础上研究了XBLs和RBLs间的光度与宽波段谱指数的相关性质. 结果表明:XBLs和RBLs之间存在着较强的相关性质,XBLs和RBLs位于不同的区域... 对Fossati等人的研究中所给出的Blazar样本分别计算从射电到X射线波段的光度、宽波段光谱指数. 在此基础上研究了XBLs和RBLs间的光度与宽波段谱指数的相关性质. 结果表明:XBLs和RBLs之间存在着较强的相关性质,XBLs和RBLs位于不同的区域,可以通过0.75rxa=较好的区分开来,这意味着它们之间的能谱分布形状是有差异的因而有助于我们了解的其内部辐射机制,最后对结果进行讨论. 展开更多
关键词 BLAZARS 光度 谱能分布 非热辐射
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XBLs和平谱射电类星体间光度与宽波段谱指数的相关性分析
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作者 丁世学 《华中师范大学学报(自然科学版)》 CAS CSCD 2006年第3期340-343,共4页
对Fossati等人所给出的Blazar样本分别计算从射电到X射线波段的光度和宽波段光谱指数,在此基础上研究了XBLs和FSRQs间的光度与宽波段谱指数的相关性质.结果表明:对XBLs和FSRQs而言可以由射电光度logLr≈43.5分布在两个不同的区域,在XBLs... 对Fossati等人所给出的Blazar样本分别计算从射电到X射线波段的光度和宽波段光谱指数,在此基础上研究了XBLs和FSRQs间的光度与宽波段谱指数的相关性质.结果表明:对XBLs和FSRQs而言可以由射电光度logLr≈43.5分布在两个不同的区域,在XBLs和FSRQs之间光度与宽波段谱指数之间的相关性要普遍强于XBLs和RBLs之间光度与宽波段谱指数之间的相关性,XBLs和FSRQs位于不同的区域,可以通过rαx=0.75较好地区分开来,这意味着它们之间的能谱分布形状是有差异的,因而有助于了解其内部辐射机制,最后对结果进行讨论. 展开更多
关键词 BLAZARS 光度 谱能分布 非热辐射
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RBLs和平谱射电类星体间峰值频率与光谱指数的相关性分析
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作者 丁世学 《华中师范大学学报(自然科学版)》 CAS CSCD 2005年第1期39-41,共3页
对Fossati等人的研究中所给出的Blazar样本分别计算同步辐射峰值频率及射电到X射线的宽波段光谱指数.在此基础上研究了RBLs和平谱射电类星体间的峰值频率与光谱指数的相关性质.结果表明:两者之间存在着较强的相关性质,XBLs和RBLs位于不... 对Fossati等人的研究中所给出的Blazar样本分别计算同步辐射峰值频率及射电到X射线的宽波段光谱指数.在此基础上研究了RBLs和平谱射电类星体间的峰值频率与光谱指数的相关性质.结果表明:两者之间存在着较强的相关性质,XBLs和RBLs位于不同的区域,可以通过αrx=0.75和logvp=14.75±0.4较好地区分开来.RBLs位于XBLs和FSRQs的中间态.这意味着它们之间的能谱分布形状是有差异的,因而有助于了解其内部辐射机制. 展开更多
关键词 BLAZARS 峰值频率 谱能分布 非热辐射
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电子设备太阳辐射模拟试验分析与探讨 被引量:5
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作者 马志宏 李金国 张景飞 《环境技术》 2007年第6期11-13,17,共4页
阐述了太阳辐射对电子产品的影响,介绍了试验的种类和进行选择的标准,重点分析了日辐射强度及其谱能分布、试验温度、湿度和风速等基本参数的确定依据和有关试验技术,并对太阳辐射试验模拟设备的研制提出设计要求,为我国自行研制非标环... 阐述了太阳辐射对电子产品的影响,介绍了试验的种类和进行选择的标准,重点分析了日辐射强度及其谱能分布、试验温度、湿度和风速等基本参数的确定依据和有关试验技术,并对太阳辐射试验模拟设备的研制提出设计要求,为我国自行研制非标环境试验设备提供了依据。 展开更多
关键词 电子设备 太阳辐射 辐射强度 谱能分布
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Beryllium-distribution in metallic glass matrix composite containing beryllium 被引量:1
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作者 郭振玺 王永胜 +7 位作者 朱陆军 张跃飞 张振华 柯小行 林均品 郝国建 张泽 隋曼龄 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期110-116,共7页
The morphologies, sizes, compositions and volume fractions of dendritic phases in in situ Ti-based metallic glass matrix composites (MGMCs) containing beryllium (Be) with the nominal composition of Tia7Zr19Cu5V12B... The morphologies, sizes, compositions and volume fractions of dendritic phases in in situ Ti-based metallic glass matrix composites (MGMCs) containing beryllium (Be) with the nominal composition of Tia7Zr19Cu5V12Be17 (mole fraction, %) were investigated using XRD, SEM, EBSD, TEM, EDS and three-dimensional reconstruction method. Moreover, visualized at the nanoscale, Be distribution is confirmed to be only present in the matrix using scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS). Based on these findings, it has been obtained that the accurate chemical compositions are Wi28.3Zr19.7Cu8V6.4Be37.6 (mole fraction, %) for glass matrix and Wi62.nZr18.aCu2.6V16.6 (mole fraction, %) for the dendritic phases, and the volume fractions are 38.5% and 61.5%, respectively. It is believed that the results are of particular importance for the designing of Be-containing MGMCs. 展开更多
关键词 metallic glass COMPOSITES microstructure electron energy loss spectroscopy Be-distribution
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Energy Dependence of Interface Trap Density——Investigated by Relaxation Spectral Technique
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作者 霍宗亮 毛凌锋 +1 位作者 谭长华 许铭真 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第1期18-23,共6页
According to the definition of interface traps,a new application of relaxation spectral technique to sub-threshold swing shift and sub-threshold gate voltage shift is proposed to extract interface trap density in 1.9n... According to the definition of interface traps,a new application of relaxation spectral technique to sub-threshold swing shift and sub-threshold gate voltage shift is proposed to extract interface trap density in 1.9nm MOSFET.And thus the energy distribution of interface trap can be determined.According to the two methods,the energy profile of interface traps agrees with those reported in literature.Compared to other methods,this method is simpler and more convenient. 展开更多
关键词 relaxation spectral technique interface trap MOS structure
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Conformations and Metal Ion Affinities of Glutamine Binding with Alkali and Alkaline Earth Metal Cations: an ab initio Study
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作者 庞瑞 带子敬 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第2期189-199,I0004,共12页
Conformations and reaction energetics are important for understanding the interactions be- tween biomolecules and metal ions. In this work, we report a systematic ab initio study on the conformations and metal ion aff... Conformations and reaction energetics are important for understanding the interactions be- tween biomolecules and metal ions. In this work, we report a systematic ab initio study on the conformations and metal ion affinities of glutamine (Gln) binding with alkali and alkaline earth metal ions. An efficient and reliable method of searching low energy conformations of metalated Gln is proposed and applied to the complexes of Gln.Gln.M^+/++(M+/++=Li^+、Na^+、K^+、Rb^+、Cs^+、Be^++、Mg^++、Ca^++、Sr^++ and Ba^++).. In addition to all conformers known in literatures, many new important conformations are located, demonstrating the power of the new method and the necessity of the conformational search performed here. The metal coordination modes, relative energies, dipole moments, and equilibrium distributions of all important conformations of Gln.M^+/++ are calculated by the methods of B3LYP, BHandHLYP, and MP2. IR spectra and metalation enthalpies and free energies are also presented and compared with the available experiments. The results form an extensive database for systematic examination of the metalation properties of Gln. 展开更多
关键词 Conformational search method Complexation structure Conformational distribution IR spectrum Binding energy
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A cooperative spectrum sensing results transmission scheme with LT code based on energy efficiency priority
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作者 Song Xiaoqin Jin Hui +2 位作者 Tan Yazhu Hu Jing Song Tiecheng 《Journal of Southeast University(English Edition)》 EI CAS 2018年第4期444-450,共7页
To deal with a sharp increase in transmission energy consumption due to the presence of a large number of secondary users( SUs),an energy-efficient cooperative spectrum sensing results transmission scheme is proposed ... To deal with a sharp increase in transmission energy consumption due to the presence of a large number of secondary users( SUs),an energy-efficient cooperative spectrum sensing results transmission scheme is proposed for cognitive radio systems. First,a cluster-based structure is introduced into the sensing results transmission scheme to reduce the transmission power. Then,the centralized sensing results transmission model is employed,and the non-fixed code rate Luby transform( LT)code is selected as the channel coding since its code rate can dynamically adapt to channel conditions and therefore avoid unnecessary redundancy in the transmission power.Furthermore,an improved optimal degree distribution( ODD)is designed for the LT code. The simulation results show that the choice of the appropriate parameters in degree distribution is very helpful for the LT code to achieve a promising performance. The ODD with optimized parameters can achieve more than 2 d B performance gain than other typical degree distributions when the bit error rate( BER) is 10-3. The energy consumption of the proposed scheme is not only at least71. 4% lower than that of the non-coding system,but also lower than that of the convolutional coding system with different code rates. Meanwhile, the energy consumption can be further reduced in the case that a suitable clustering method is selected. 展开更多
关键词 cooperative spectrum sensing ENERGY-EFFICIENT cluster-based Luby transform (LT) code degree distribution
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The Statistical Distribution for 0-Deformed Crystal Lattice Vibration for Generic Atomic String
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作者 Nguyen Thi Ha Loan 《Journal of Physical Science and Application》 2014年第2期136-138,共3页
In this paper, a g-deformation of crystal lattice vibration for generic atomic string is suggested. The expression for energy spectrum depends on g-deformed parameter have been obtained. The statistical distribution o... In this paper, a g-deformation of crystal lattice vibration for generic atomic string is suggested. The expression for energy spectrum depends on g-deformed parameter have been obtained. The statistical distribution of g-deformed crystal lattice vibration is calculated and this result is very much different from there of q-deformed crystal lattice vibration. 展开更多
关键词 Quantum CRYSTAL LATTICE VIBRATION
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Proton angular distribution research by a new angle-resolved proton energy spectrometer 被引量:1
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作者 SU LuNing ZHENG Yi +14 位作者 LIU Meng HU ZhiDan WANG WeiMin YUAN XiaoHui XU MiaoHua SHENG ZhengMing SHEN ZhongWei FAN HaiTao LI YuTong MA JingLong LU Xin CHEN LiMing WANG ZhaoHua WEI ZhiYi ZHANG Jie 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第5期844-848,共5页
The proton spectral and angular distributions simultaneously within the target normal direction and laser propagation direction by using an angle-resolved proton energy spectrometer are studied.For the protons generat... The proton spectral and angular distributions simultaneously within the target normal direction and laser propagation direction by using an angle-resolved proton energy spectrometer are studied.For the protons generated in the interactions of 100 fs,800nm laser pulses with aluminum foil targets,the deviations of proton beam centers of different energies from the target normal direction towards the laser propagation direction are different.This is probably because of the toroidal magnetic fields generated at the rear target surface,which deflect protons transversely.As a result,protons in low energy range have large deviation angles,protons in middle energy range have the smallest deviation angles,while protons in high energy tail have large deviation angles. 展开更多
关键词 LASER-DRIVEN PROTON ACCELERATION
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The nature of[S Ⅲ]λλ9096,9532 emitters at z=1.34 and 1.23
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作者 AN FangXia ZHENG XianZhong +3 位作者 MENG YanZhi CHEN Yang WEN ZhangZheng L GuoLiang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第11期2226-2235,共10页
A study of[S Ⅲ]λλ9096,9532 emitters at z=1.34 and 1.23 is presented using our deep narrow-band H2S 1(centered at 2.13μm)imaging survey of the Extended Chandra Deep Field South(ECDFS).We combine our data with multi... A study of[S Ⅲ]λλ9096,9532 emitters at z=1.34 and 1.23 is presented using our deep narrow-band H2S 1(centered at 2.13μm)imaging survey of the Extended Chandra Deep Field South(ECDFS).We combine our data with multi-wavelength data of ECDFS to build up spectral energy distributions(SEDs)from the U to the Ks-band for emitter candidates selected with strong excess in H2S 1 Ks and derive photometric redshifts,line luminosities,stellar masses and extinction.A sample of 14[S Ⅲ]emitters are identified with H2S 1<22.8 and Ks<24.8(AB)over 381 arcmin2area,having[S Ⅲ]line luminosity L[S Ⅲ]=~1041.5 42.6erg s 1.None of the[S Ⅲ]emitters is found to have X-ray counterpart in the deepest Chandra 4 Ms observation,suggesting that they are unlikely powered by AGNs.The HST/ACS F606W and HST/WFC3 F160W images show their rest-frame UV and optical morphologies.About half of the[S Ⅲ]emitters are mergers and at least one third are disk-type galaxies.Nearly all[S Ⅲ]emitters exhibit a prominent Balmer break in their SEDs,indicating the presence of a significant post-starburst component.Taken together,our results imply that both shock heating in post-starburst and photoionization caused by young massive stars are likely to excite strong[S Ⅲ]emission lines.We conclude that the[S Ⅲ]emitters in our sample are dominated by star-forming galaxies(SFGs)with stellar mass 8.7<log(M/M⊙)<9.9. 展开更多
关键词 galaxies: evolution galaxies: high-redshift galaxies: emission lines [S Ⅲ]
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Effects of binary interactions on the color evolution of M33
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作者 KANG XiaoYu ZHANG FengHui ZHANG Yu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第8期1505-1509,共5页
In this work, predictions of the spectral energy distribution from populations of single and binary stars are incorporated into a galactic chemical and color evolution model to explore the significance of the effects ... In this work, predictions of the spectral energy distribution from populations of single and binary stars are incorporated into a galactic chemical and color evolution model to explore the significance of the effects of the binary interactions on the color evolution of M33. We first constructed a model without binary interactions, and the model is able to reproduce most of the available observational constraints on the distribution of stellar parameters. We then run simulations with the same set of model parameters but with binary interactions considered. By comparing the results for the populations with and without binary interactions, we find that the inclusion of binary interactions makes the surface brightness greater (~0.1 mag arcsec 2) in FUV-band but smaller (~0.7 mag arcsec 2) in K-band, while it results in the FUV K color bluer (~0.8 mag). To reproduce the observations, a model that considers the binary interactions should make more gas fall onto the disk in the early time of the galaxy evolution, or increase the total stellar mass, or both. 展开更多
关键词 M33 EVOLUTION binary stars
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