Research of the active reflector antenna using laser angle metrology system

Active reflector is one of the key technologies for constructing large telescopes, especially for the millimeter/sub-millimeter radio telescopes. This article introduces a new efficient laser angle metrology system for the active reflector antenna of the large radio telescopes, with a plenty of active reflector experiments mainly about the detecting precisions and the maintaining of the surface shape in real time, on the 65-meter radio telescope prototype constructed by Nanjing Institute of Astronomical Optics and Technology (NIAOT). The test results indicate that the accuracy of the surface shape segmenting and maintaining is up to micron dimension, and the time-response can be of the order of minutes. Therefore, it is proved to be workable for the sub-millimeter radio telescopes.Comment: 10 pages, 15 figure

Hydrogenation of Alkali Lignin Catalyzed by Pd/C

AbstractHydrogenation of alkali lignin was carried out in the presence of Pd/C catalyst at hydrogen pressure 1∼5 MPa. Catalytic activity of Pd/C catalyst was investigated according to the structure changes of alkali lignin, which were characterized by UV and 1H-NMR spectroscopy. The measurement of average molecular weight undertook by gel permeation chromatography (GPC). Changes on function groups of alkali lignin were analyzed through chemical methods. Results show that total hydroxyl, phenolic hydroxyl and alcoholic hydroxyl increase 64.23%, 37.10% and 89.67%, respectively, while carbonyl and carboxyl decrease separately 43.50% and 53.41%. No significant differences of the total acidic groups and the phenyl structure were found after reaction. GPC analysis shows the weight average molecular weight (Mw) and number average molecular weight (Mn) are both decreased, and the polydispersity of alkali lignin is increased The active function groups of alkali lignin are increased obviously, and reactive activity of alkali lignin is enhanced as a result. The present results demonstrate Pd/C catalyst shows an excellent catalytic activity on reductive reaction of alkali lignin and hydrogen

Fuzzy reasoning spiking neural P system for fault diagnosis

Spiking neural P systems (SN P systems) have been well established as a novel class of distributed parallel computing models. Some features that SN P systems possess are attractive to fault diagnosis. However, handling fuzzy diagnosis knowledge and reasoning is required for many fault diagnosis applications. The lack of ability is a major problem of existing SN P systems when applying them to the fault diagnosis domain. Thus, we extend SN P systems by introducing some new ingredients (such as three types of neurons, fuzzy logic and new firing mechanism) and propose the fuzzy reasoning spiking neural P systems (FRSN P systems). The FRSN P systems are particularly suitable to model fuzzy production rules in a fuzzy diagnosis knowledge base and their reasoning process. Moreover, a parallel fuzzy reasoning algorithm based on FRSN P systems is developed according to neuron’s dynamic firing mechanism. Besides, a practical example of transformer fault diagnosis is used to demonstrate the feasibility and effectiveness of the proposed FRSN P systems in fault diagnosis problem.Ministerio de Ciencia e Innovación TIN2009–13192Junta de Andalucía P08-TIC-0420

The properties of the high-mass star formation region IRAS22475+5939

IRAS22475+5939 has been well researched by previous astronomers. But we still get some new characteristics about it, using the first observations in lines of CO J=2-1,13CO J=2-1,13CO J=3-2 by the KOSMA 3 m telescope. The mapping of the intensity ratio of 13CO J=3-2 and 13CO J=2-1 shows the distribution of the temperature with two peaks, which don't coincide with IRAS22475+5939 source and the center of the HII region, but at the edge of the HII region. The overlays of the Spitzer IRAC 8um and CO contours indicate that they are associated with each other and the strongest polycyclic aromatic hydrocarbons (PAHs) emission is at the position of IRAS22475+5939 source. While the IRAS LRS spectrum at 7-23 um and the PHT-s spectrum at 2-12 um of IRAS22475+5939 source also exhibit strong PAHs emission characters at the main PAH bands. The diversity of PAH family should be responsible for the plateaus of PAHs emission in the PHT-s spectrum and the IRAS-LRS spectrum. An analysis and modeling in infrared bands suggest that IRAS22475+5939 is more likely to be a Class I YSO. Where this is the case, the star is likely to have a temperature T_{EFF} \sim 9995.8 K, mass \sim15.34 M_(sun), luminosity \sim 1.54*10^4 L_(sun) and age \sim 1.54*10^4 yr. The model shows that the circumstellar disc emission is important for the wavelength between 1 and 10 um, otherwise, envelope fluxes for lambda >10 um. The bipolar outflow is confirmed in the molecular cloud. The excited star of the HII region has the chance to be the driving source of the outflow. The high resolution is required.Comment: 12 pages, 20 figures and 5 tables, Accepted for publication in RA

Isospin dependence of projectile-like fragment production at intermediate energies

The cross sections of fragments produced in 140 $A$ MeV $^{40,48}$Ca + $^9$Be and $^{58,64}$Ni + $^9$Be reactions are calculated by the statistical abration-ablation(SAA) model and compared to the experimental results measured at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The fragment isotopic and isotonic cross section distributions of $^{40}$Ca and $^{48}$Ca, $^{58}$Ni and $^{64}$Ni, $^{40}$Ca and $^{58}$Ni, and $^{48}$Ca and $^{64}$Ni are compared and the isospin dependence of the projectile fragmentation is studied. It is found that the isospin dependence decreases and disappears in the central collisions. The shapes of the fragment isotopic and isotonic cross section distributions are found to be very similar for symmetric projectile nuclei. The shapes of the fragment isotopic and isotonic distributions of different asymmetric projectiles produced in peripheral reactions are found very similar. The similarity of the distributions are related to the similar proton and neutron density distributions inside the nucleus in framework of the SAA model.Comment: 7 pages, 4 figures; to be published in Phys Rev