搜索结果: 91-105 共查到“理学 X-ray”相关记录739条 . 查询时间(0.078 秒)
Angular distribution of Bremsstrahlung photons and of positrons for calculations of terrestrial gamma-ray flashes and positron beams
Bremsstrahlung pair production analytical integration of Bethe-Heitler equation distribution of scattering angles
2012/2/28
Within thunderstorms electrons can gain energies of up to hundred(s) of MeV. These electrons can create X-rays and gamma-rays as Bremsstrahlung when they collide with air molecules. Here we calculate ...
The Gamma-Ray Blazar PKS 0208-512, a Multi-Wavelength Investigation
Gamma-Ray Blazar PKS 0208-512 Multi-Wavelength Investigation
2012/2/23
The gamma-ray blazar PKS 0208-512 has shown strong periods of flaring, at all frequencies from radio to gamma-ray. This has led to its inclusion in the TANAMI project, which tracks the jets of souther...
Thermonuclear X-ray bursts from the 401 Hertz accreting pulsar IGR J17498-2921: indication of burning in confined regions
Thermonuclear X-ray bursts pulsar IGR J17498-2921 indication confined regions
2012/2/23
We use the 2011 Rossi X-ray Timing Explorer (RXTE) proportional counter array (PCA) data of the 401 Hz accreting pulsar and burster IGR J17498-2921 to perform timing analysis and time-resolved spectro...
Assessing the Feasibility of Cosmic-Ray Acceleration by Magnetic Turbulence at the Galactic Center
Feasibility Cosmic-Ray Acceleration Magnetic Turbulence the Galactic Center
2012/2/23
The presence of relativistic particles at the center of our galaxy is evidenced by the diffuse TeV emission detected from the inner $\sim$$2^\circ$ of the Galaxy. Although it is not yet entirely clear...
The Search for High-Mass X-ray Binaries in the Phoenix Dwarf Galaxy
High-Mass X-ray Binaries Phoenix Dwarf Galaxy
2012/2/23
We report on the first X-ray images of the Phoenix dwarf galaxy, taken with \emph{XMM-Newton} in July 2009. This local group dwarf galaxy shares similarities with the Small Magellanic Cloud (SMC) incl...
Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
Fermi-LAT Observations Diffuse Gamma-Ray Emission Implications Cosmic Rays the Interstellar Medium
2012/2/23
The gamma-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissio...
英国Ray Dixon教授访问中国科学院微生物研究所
英国 Ray Dixon 教授 访问 中国科学院微生物研究所 生物固氮分子生物学 大肠杆菌 一氧化氮感应 转录因子
2012/2/24
2012年2月17日上午， 英国John Innes Centre的Ray Dixon教授应谭华荣研究员的邀请，对中国科学院微生物研究所进行了学术访问。Ray Dixon教授是世界著名的生物固氮分子微生物学家，是国际上最早开展生物固氮分子生物学研究的先驱者，在本领域已经发表高水平研究论文百余篇，其中8篇发表在Nature，1999年被选为英国皇家学会会员(FRS)，现任John Innes Cen...
Frame-dragging, disk warping, jet precessing, and dipped X-ray lightcurve of Sw J1644+57
Frame-dragging disk warping jet precessing dipped X-ray lightcurve Sw J1644+57
2012/2/23
The X-ray transient source Sw J1644+57 recently discovered by Swift is believed to be triggered by tidal disruption of a star by a rapidly spinning supermassive black hole (SMBH). For such events, the...
The contribution from blazar cascade emission to the extragalactic gamma-ray background: What a role does the extragalactic magnetic field play?
diffuse radiation galaxies active gamma rays general
2012/2/21
We estimate the contribution to the extragalactic gamma-ray background (EGRB) from both intrinsic and cascade emissions produced by blazars using a simple semi- analysis method for two models of the b...
Rebirth of X-ray Emission from the Born-Again Planetary Nebula A 30
Rebirth X-ray Emission Born-Again Planetary Nebula
2012/2/23
The planetary nebula (PN) A 30 is believed to have undergone a very late thermal pulse resulting in the ejection of knots of hydrogen-poor material. Using multi-epoch HST images we have detected the a...
Synchrotron based Transmission x-ray microscopy reveals smectite fine structure in an aqueous environment
Synchrotron Transmission x-ray microscopy reveals smectite fine structure aqueous environment
2012/3/30
The unusual behaviour of smectites, the ability to change volume when wetted (swelling) or dried (shrinking), make soil containing smectites very unstable and hazardous for the building industry due t...
MINERALOGICAL ABUNDANCES AS DETERMINED BY X-RAY DIFFRACTION IN SELECT SAMPLES OF THE UPPER FLORIDA AQUIFER
MINERALOGICAL ABUNDANCES X-RAY DIFFRACTION FLORIDA AQUIFER
2011/11/11
Analysis of 53 bulk powders derived from various rocks of the Upper Floridan Aquifer reveal calcite, dolomite/ankerite, quartz, apatite, and smectite to be the dominant minerals, with the clay and apa...
TRACE ELEMENT DETERMINATIONS COMPARED WITH X-RAY DIFFRACTION RESULTS OF BROWN CLAY IN THE CENTRAL PACIFIC
BROWN CLAY X-RAY DIFFRACTION THE CENTRAL PACIFIC
2011/11/8
Prior to DSDP Leg 17, no sites drilled in the central Pacific had continuously cored a thick section of pelagic brown clay. On Leg 6 several sites were drilled through brown clay, but poor recovery du...
Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of sepiolite and palygorskite
X-ray diffraction sepiolite palygorskite
2011/11/4
Real-time, temperature-resolved synchrotron powder X-ray diffraction data and Rietveld refinements provide unprecedented insights into mineral behaviors and mechanisms of crystal structure transformat...
In-Situ Identification of Palygorskite in Maya Blue Samples Using X-Ray Powder Diffraction
Palygorskite X-Ray Powder Diffraction Maya Blue Samples
2011/11/4
In spite of the abundance of colors found in the murals and other objects that correspond to the Classic Mayan period (600-900 A.D.), a peculiar hue captured the interest of researchers. The most well...