Primordial black holes and Holeums as progenitors of Galactic diffuse gamma-ray background

Diffuse Galactic gamma-ray flux resulting from the evaporation of primordial black holes has been the subject of intensive research work during the last few decades. Theoretical work addressing this issue started in the 1970s whereas data started pouring in only in the 1990s. We discuss in this paper a model of the potential contribution to the Galactic gamma-ray flux of primordial black holes in binary systems and extend the argument to include stable gravitational bound states called Holeums. The model has a predictive power and can be tested by looking for gamma-ray excess in the vicinity of violent events occurring in the Galaxy such as supernova explosions.     

飞机铆接电阻专用测量仪的研制

飞机铆接电阻专用测量仪是用于测量飞机铆接部件接触质量的专用仪器,它对保证飞机机载电子设备和通讯系统正常工作具有重要作用,在飞机维护中也常常要检测机体电阻是否符合要求.本文介绍了该测量仪的研制目的、工作原理和电路组成.     

A multi-epoch study of the C IV absorption variability in the broad absorption line quasar APM 08279+5255

Broad absorption line (BAL) variability potentially represents a powerful tool to investigate the physical nature and the structure of gas outflows in active galactic nuclei. Most existing BAL variability studies rely on observations taken at a few epochs for samples of tens of BAL QSOs. In this study we present the first “monitoring” of a single object, APM 08279+5255, which has been observed more than 20 times since 2003. All available spectra from the literature have also been analysed, including two high resolution spectra, extending the time interval from 1998 to 2012. A relative stability of the shape of the absorption profile is found. At the same time significant variations of the equivalent width are observed. A correlation of the BAL equivalent width with the QSO luminosity is found for the first time. These results suggest that changes in the ionisation state of the gas are causing opacity changes.     

Low ionization lines in high luminosity quasars: The calcium triplet

In order to investigate where and how low ionization lines are emitted in quasars we are studying a new collection of spectra of the CaII triplet at λ8498, λ8542, λ8662 observed with the Very Large Telescope (VLT) using the Infrared Spectrometer And Array Camera (ISAAC). Our sample involves luminous quasars at intermediate redshift for which CaII observations are almost nonexistent. We fit the CaII triplet and the OI λ8446 line using the Hβ profile as a model. We derive constraints on the line emitting region from the relative strength of the CaII triplet, OI λ8446 and Hβ.     

宇宙膨胀动因的另类物理解释

利用磁流体力学的基本概念，试图对宇宙膨胀——总星系扩张的动因，提出另类物理解释如下：磁压是导致磁力线疏散的一种斥力。由于宇宙磁场是冻凝场，故当磁力线在空问疏散时，必将带着与之冻结的宇宙物质一起在空问疏散；从而使宇宙物质的密度减少，各星彼此远离。因此可以认为，磁压是宇宙膨胀的主要动因。并就有关问题进行了讨论。     

AN ANALYSIS OF PROPELLER LIFTING－LINE THEORY BY MATCHED ASYMPTOTIC EXPANSIONS

ＡＮＡＮＡＬＹＳＩＳＯＦＰＲＯＰＥＬＬＥＲＬＩＦＴＩＮＧ－ＬＩＮＥＴＨＥＯＲＹＢＹＭＡＴＣＨＥＤＡＳＹＭＰＴＯＴＩＣＥＸＰＡＮＳＩＯＮＳＣｈｅｎＺｅｍｉｎ；ＰａｎＪｉｅｙｕａｎ；ＷｕＬｉｙｉ（ＩｎｓｔｉｔｕｔｅｏｆＦｌｕｉｄＭｅｃｈａｎｉｃｓ，Ｂｅｉ...     

变壁厚气冷涡轮叶片结构参数化设计方法

叶片叶身截面内腔型线的光滑过渡是航空发动机变壁厚涡轮叶片结构设计的关键.为解决变壁厚插值在最大壁厚点处出现拐点而导致过渡不光滑的问题,提出变壁厚叶片结构设计方法即变壁厚抛物线插值法.该方法基于管道相交投影线拟合中弧线法,利用壁厚系数及其对应关系控制壁厚,实现变壁厚涡轮叶片结构参数化设计.设计实例结果表明:应用变壁厚抛物线插值法对不同壁厚气冷涡轮叶片进行结构设计,叶身截面内腔型线光滑,在最大壁厚点处不会出现拐点过渡.     

Remnants of compact binary mergers

We investigate the long-term evolution and observability of remnants originating from the merger of compact binary systems and discuss the differences to supernova remnants. Compact binary mergers expel much smaller amounts of mass at much higher velocities, as compared to supernovae, which will affect the dynamical evolution of their remnants. The ejecta of mergers consist of very neutron rich nuclei. Some of these neutron rich nuclei will produce observational signatures in form of gamma ray lines during their decay. The composition of the ejecta might even give interesting constraints about the internal structure of the neutron star. We further discuss the possibility that merger remnants appear as recently discovered ‘dark accelerators’ which are extended TeV sources which lack emission in other bands.     

钢筋砼轴对称扁壳基于双剪屈服准则的极限分析的塑性屈服线方法

文章利用基于双剪屈服线准则所导出的钢筋砼壳体的屈服条件，并利用塑性屈服线方法求解钢筋砼轴对称双曲扁壳在竖向荷载下的极限载荷。     

质量准则在分析《雷雨》台词原文与译文中的应用

众所周知，翻译的要旨在于忠实于原文。从语用学的合作原则来看，译者首先须遵循质量准则。基于此，本文选取《雷雨》中的两组台词的原文与译文进行了分析和评鉴。