GRB 980703射电、光学和红外余辉的数值模拟研究

GRB 980703有丰富的多波段余辉观测数据. 特别是它的射电余辉非常明亮以至于在爆发后1000多天还能被观测到. 此外, 它的多波段余辉光变曲线中没有特殊的特征, 也就是说没有增亮、平台、快速衰减或缓慢衰减等现象. 以上这些特点使得GRB 980703成为伽玛暴研究领域中一个十分难得的样本. 在本文中利用GRB 980703的观测数据来详细地检验伽玛暴余辉的标准火球模型, 计算结果表明火球模型可以满意地解释伽玛暴多波段余辉光变曲线的行为. 拟合得到的GRB 980703的物理参数如下： 喷流的半张角约为Θ0≈0.23 radian; 暴周围环境介质密度约为n≈27cm-3; 火球各向同性总能量约为E0≈3.8×1052 ergs; 伽玛暴寄主星系对视线方向的消光贡献约为AV≈2.5 mag.     

伽玛暴光学余辉中的双喷流成份行为

伽玛暴余辉的双拐折行为可以用双喷流成份结构模型得到较好的解释,但至今其物理参数还未解。为给出其相应的物理参数,文中将对具有双喷流成份的伽玛暴光学余辉进行统计分析,用外激波模型时域指数α和频域指数β的关系(closure relation)对数据进行限制,得到GRB 071003,GRB 080319B,GRB 090426和GRB 100219A共4个具有外激波模型的伽玛暴双成份喷流特征。这些伽玛暴第一个喷流成份的张角都在1°以内,而第二个喷流成份的张角增大到2°~7°,与单成份喷流的张角一致。其各向同性辐射能量在1051~1054erg,电子谱指数p约为2,比典型值2.3硬。长暴能较好符合Amati关系。     

费米GRB170826B时间分辨谱的同步辐射拟合

采用光滑截断双幂律谱(Band)、单幂率同步(SYNPL)和拐折幂率同步(SYNBPL)三个模型拟合费米GBM亮暴GRB170826B的时间分辨谱,并计算谱宽度W和谱锐度角θ,得到以下结果:(1)三个模型对该暴的能谱拟合较好并且拟合结果基本一致,表明同步模型能够解释该暴的能谱;(2)GRB170826B的单幂率同步p指数在4.88左右,Band和SYNBPL给出它的高能光谱比较陡,并且需要更多的高能光子来准确限制高能谱指数;(3)使用谱宽度W和谱锐度角θ等辅助量来测试同步模型解释伽马暴谱能力的方法存在争议,因为比较同步谱和伽马暴谱的这两个量表明有些伽马暴谱不能被同步解释,而这些谱却能被同步模型拟合.     

从谱演化方面的信息探讨GRB 061007的暴周环境

GRB 061007是一个明亮的、长时标的伽玛射线暴(简称伽玛暴),其红移为1.261.一方面,Swift/XRT观测到的数据显示,此暴X射线波段的光变曲线呈现出单一幂率形态,且幂率指数αXRT=1.68±0.01.另一方面,经由Faulkes Telescope South(简写为FTS)提供的BVRi'多波段光学余辉数据,作者分析发现其各波段光变曲线的幂率指数αOptical均在1.6左右.拟合得到的2个波段幂率指数如此相近,也就意味着此暴的X射线波段和光学波段具有同一起源.作者通过分析X射线波段和光学波段的谱演化情况,探究GRB 061007的暴周环境.分析的结果显示,X射线波段的谱指数β没有演化,而光学波段的谱有向蓝端演化的趋势.根据其光学波段谱的演化趋势,推测此暴的暴周环境不是均匀介质,而应是星风环境.     

伽玛射线暴内光度和峰值能量关系的统计分析

以前的研究表明:在伽玛射线暴(简称伽玛暴)间各向同性等值光度Liso和静止系中vFv谱的峰值能量E′p之间存在关系式LisooE′p2.Liang等人用Preece等人给出的91个BATSE伽玛暴的2408个时间分辨谱样本对这一关系式进行了验证,得出这一关系式不但在伽玛暴内成立,而且在伽玛暴之间也是成立的.为了进一步验证这一关系式,我们收集了Kaneko等人2006年发表的350个BATSE伽玛暴能谱的数据,并对其中185个伽玛暴能谱的5218个时间分辨谱样本进行统计分析,我们得出的结果与Liang等人的结果是一致的.     

从谱演化方面的信息探讨 GRB 061007 的暴周环境

GRB 061007是一个明亮的、长时标的伽玛射线暴（简称伽玛暴）,其红移为1．261．一方面,Swift／XRT观测到的数据显示,此暴X射线波段的光变曲线呈现出单一幂率形态,且幂率指数αXRt=1．68±0．01．另一方面,经由Faulkes Telescope South（简写为FTS）提供的BVRi’多波段光学余辉数据,作者分析发现其各波段光变曲线的幂率指数αOptical均在1．6左右．拟合得到的2个波段幂率指数如此相近,也就意味着此暴的X射线波段和光学波段具有同一起源．作者通过分析X射线波段和光学波段的谱演化情况,探究GRB061007的暴周环境．分析的结果显示,X射线波段的谱指数JB没有演化,而光学波段的谱有向蓝端演化的趋势．根据其光学波段谱的演化趋势,推测此暴的暴周环境不是均匀介质,而应是星风环境．     

考虑同步自吸收的γ暴能谱

重点讨论有自吸收的γ射线暴余辉的能谱，考虑了在火球模型中同步加速辐射中的自吸收效应，用含有吸收系数的同步加速辐射谱公式计算了GRB970508余辉的辐射谱．解释了GRB970508射电和光学波段余辉的光变曲线的特征．     

γ射线暴火球模型的光学余辉辐射

按照γ射线暴火球模型的动力学演化规律,利用相对论电子在磁场中作同步加速辐射时谱分布的特点,用求峰值频率辐射的方法,计算了γ射线暴红光波段余辉辐射流量随时间的变化与γ射线暴GRB970228的观测结果比较,符合甚好,说明同步加速辐射是γ射线暴余辉主要的辐射机制,也进一步证明了火球模型的正确。     

探讨GRB光变曲线的Flux与T90的关系

探讨了GRB(Gamma-Ray Burst,伽玛射线暴)光变曲线的Flux(光子峰值流量)与T90(GRB光子计数在5%~95%之间的持续时标)的关系.分别采用两颗卫星的最新数据,对Flux与T90进行相关分析.结果为:Flux与T90的对数值之间不显相关性,相关系数分别为R~0.12和R~0.04,表明GRB的持续时间与光变曲线的光子峰值流量不相关.     

磁场对中微子主导吸积盘粒子丰度的影响

中微子主导吸积盘被认为可能是伽玛射线暴中心能源机制的一种模型.为了详细地考虑微观粒子分布,计算了伪牛顿势框架下磁场对中微子主导吸积盘微观粒子丰度的影响.结果表明,在吸积盘的外区,磁场对粒子丰度和电子简并度几乎没有影响；而在吸积盘的内区,考虑和没考虑磁场时,电子简并度,电子、中子等粒子丰度具有比较大的差异.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to