高负荷下带重尾服务强占优先排队的扩散逼近

考虑的排队系统是单服务台,顾客的初始到来是依泊松过程来到服务台,顾客的服务时间是重尾分布,服务的原则是强占优先服务.在高负荷条件下对此模型进行研究,获得了系统中的负荷过程,离去过程和队长过程的扩散逼近.     

Where galaxies really come from

The fundamental paradox of the incompatibility of the observed large-scale uniformity of the Universe with the fact that the age of the Universe is finite is overcome by the introduction of an initial period of superluminal expansion of space, called cosmic inflation. Inflation can also produce the small deviations from uniformity needed for the formation of structures in the Universe such as galaxies. This is achieved by the conjunction of inflation with the quantum vacuum, through the so-called particle production process. This mechanism is explained and linked with Hawking radiation of black holes. The nature of the particles involved is discussed and the case of using massive vector boson fields instead of scalar fields is presented, with emphasis on its distinct observational signatures. Finally, a particular implementation of these ideas is included, which can link the formation of galaxies, the standard model vector bosons and the observed galactic magnetic fields.     

Synthesis and Characterization of Magnetic Polymer Microspheres

In this study, amino group–modified magnetic polymer microspheres were synthesized in a well‐shaped spherical form with a size range of 0.6 μm to 0.8 μm by mini‐emulsion polymerization. The morphology, composition, and thermal properties of the magnetic polymer microspheres were characterized by infrared (IR) spectra, transmission electron microscopy (TEM) photographs, particle size analysis, and thermogravimetric analysis (TGA) spectra. The results demonstrate that acrylic acid used for stabilizing the reaction system greatly affects the particle size, magnetite contents, and thermal stability of magnetic polymer microspheres.     

Negative viscosity due to magnetic properties of a non-dilute suspension composed of ferromagnetic rod-like particles with magnetic moment normal to the particle axis

The negative viscosity of a colloidal dispersion composed of ferromagnetic rod-like particles, which have a magnetic moment normal to the particle axis, have been investigated. A simple shear flow problem has been treated to clarify the particle orientational distribution and rheological properties of such a semi-dense dispersion, under circumstances of an external magnetic field applied in the direction normal to the shear plane of a simple shear flow. The results obtained here are summarized as follows. For the cases of a very strong magnetic field and magnetic interactions between particles, the magnetic moment of the rod-like particles is significantly restricted in the magnetic field direction, so that the particle approximately aligns in the shear flow direction. Also, the particle can easily rotate around the axis of the cluster almost freely even in a simple shear flow. Characteristic orientational properties of the particle cause negative viscosity, as in the previous study for a dilute dispersion. However, magnetic particle-particle interactions have a function to make such negative viscosity decrease.     

The Effects of Storage on CR-39

The effects of storage temperatures on the track registration of CR-39 as a solid state nuclear track detectors have been investigated. The results show that the storage CR-39 detectors cause partial or complete removal of tracks depending on storaged time and temperatures. The bulk activation energy for CR-39 has been found to be 0.883 eV.     

Comment on “On the Anomalon Interpretation of 40Ar + Cu Collisions at 0.9 and 1.8 AGeV”

A recent article interpreted the experiment by Dersch et al. on the formation of ²⁴Na in ⁴⁰Ar + Cu interactions in a very simple manner. The results from emulsion experiments performed with 3.6 AGeV ²²Ne were adapted for the interpretation of the experiments with 1.8 AGeV ⁴⁰Ar. The model used the same mean value for the energy of minimum ionizing protons and pions at all angles. It is argued that a more complex approach is needed for a satisfactory interpretation.     

Alpha Particle Response of CR-39 Polycarbonated Detector

The alpha particle response which is characteristic of polycarbonate detectors CR-39 has been investigated. The track diameter as a function of alpha energy in the range from 5.1–22.2 MeV was examined. The mean track diameter or size of the tracks are found to be energy dependent which decreases as alpha energy increases with a trend at about 14 MeV alpha energy. With regard to the spectroscopy of alpha from track radii, it was stated that the discrimination of lower alpha energies shows better results than the high energies for the present etching condition.

Es wurde die charakteristische Wirkung von Alpha-Teilchen auf die Polycarbonatdetektoren CR-39 untersucht. Der Spurendurchmesser als Funktion der Alpha-Energie wurde im Energiebereich 5,1… 22,2 MeV verfolgt. Der mittlere Spurendurchmesser oder die Spurengroβe waren energieabhängig und nahmen mit zunehmender Alpha-Energie bei einem Trend von ungefähr 14 Me V ab. In being auf die Spektroskopie von Alpha-Teilchen von den Spurenradien wurde festgestellt, daβeine Unterscheidung von niederen Alpha-Energien bessere Ergebnisse brachte als solche bei hohen Energien für die vorliegende Ätzbedingung.     

Comparison of Makrofol-E and CR-39 as Solid State Nuclear Track Detectors

A comparison of the etching parameters as well as the neutron response for Makrofol-E and CR-39 was considered as solid state nuclear track detectors. The calculated sensitivity for both detectors was compared with the measured one. It is found that CR-39 has higher response to fast neutrons than Makrofol-E. The response increase due to decreasing the rate of layer removed and increasing the etch-pits per unit area.     

Untersuchung von Mischvorgängen bei der Herstellung von Kohlenstoffund SiC-Werkstoffen mit Hilfe der Methodik der radioaktiven Markierung

Fūr die Herstellung von Kohlenstoff- und SiC-Werkstoffen ist eine gute Vermischung der festen und flüssigen Komponenten die notiwendige Voraussetzung. Da andere Methoden meist zu zeitaufwendig sind, wurden im VEB EKL seit mehr als 10 Jahren Versuchsreihen mit der Methodik der radioaktiven Markierung einer der Mischungskomponenten zur Untersuchung des Mischvorgangs für Maschinen bis zu 2000 kg Fülung angewandt, wobei sich die Fremdmarkierung mit ⁸²Br-Naphthalin als vorteilhaft erwiesen hat. Der Mischungszustand wird durch statistische Auswertung der Radioaktivität von Probenserien, deren γ-Strahlung gemessen wird und deren Masse in Abhängigkeit von der Mischergröβ 1 bis 100 g je Probe beträgt, charakterisiert. Zusätzlich wird die Feinverteilung durch Kontaktautoradiographie von ebenen Probenoberflächen, ebenfalls für Probenserien, bestimmt.     

组合几何蒙特卡罗粒子输运支撑软件框架JCOGIN介绍

介绍了JCOGIN支撑软件框架层次式、模块化的体系结构及其核心数据结构。这些使得JCOGIN软件框架能够支撑大规模复杂几何的蒙特卡罗（MC）粒子输运并行计算。同时介绍了在JCOGIN支撑软件框架下研发的JMCT程序,并进行了性能测试,在2万处理器核上模拟20亿粒子,并行效率达到70%。