On the inverse Compton scattering model of radio pulsars

Some characteristics of the inverse Compton scattering (ICS) model are reviewed. At least the following properties of radio pulsars can be reproduced in the model: core or central emission beam, one or two hollow emission cones, different emission heights of these components, diverse pulse profiles at various frequencies, linear and circular polarization features of core and cones.Comment: 5 pages, no figures, LaTeX, a proceeding paper for Pacific Rim Conference on Stellar Astrophysics, Aug. 1999, HongKong, Chin

Influences of the disease resistance conferred by the individual transgenes, Pi-d2, Pi-d3 and Xa21, on the transgenic rice plants in yield and grain quality

To research possible influences of the disease resistance conferred by different trans-resistance genes on the transgenic rice plants in their yields and grain quality, three transgenic rice lines, including two with the resistance genes Pi-d2 and Pi-d3, respectively, for rice blast, and one with the resistance gene Xa21 for rice bacterial blight, which all showed the highest resistance to their respective pathogen races, were used to analyze and measure their respective characters in yield and grain quality as compared to those of the transgenic control line with the empty vector that was used to transfer Pi-d2, Pi-d3 and Xa21, respectively. Both yield and grain quality of all three transgenic materials with the respective trans-resistance genes decreased significantly. Grain weight per plant of Pi-d2, Pi-d3 and Xa21 transgenic individuals decreased by 7.7%, 29.6 and 44.4%, respectively, compared to the control. Grain quality of Pi-d2 and Pi-d3 transgenic plants were both the third class according to the Industrial Standard, ‘Grain Quality of Edible Rice Variety’ and one class worse than that of the control, but the third class still belongs to edible grains. However, grain quality of Xa21 transgenic plants was too bad to be edible

Experimental investigation of a solar collector integrated with a pulsating heat pipe and a compound parabolic concentrator

The paper reports an experimental investigation of a newly proposed solar collector that integrates a closed-end pulsating heat pipe (PHP) and a compound parabolic concentrator (CPC). The PHP is used as an absorber due to its simple structure and high heat transfer capacity. The CPC has a concentration ratio of 3.4 and can be readily manufactured by three-dimensional printing. The CPC can significantly increase the incident solar irradiation intensity to the PHP absorber and also reduce the heat loss due to the decrease in the area of the hot surface. A prototype of the solar collector has been built, consisting of a PHP absorber bent by 4 mm diameter copper tube, CPC arrayed by 10 × 2 CPC units with the collection area of 300 × 427.6 mm2, a hot water tank and a glass cover. HFE7100 was utilized as the working fluid at a filling ratio of 40%. The operating characteristics and thermal efficiency of the solar collector were experimentally studied. The steady and periodic temperature fluctuations of the evaporation and condensation sections of the PHP absorber indicate that the absorber works well with a thermal resistance of about 0.26 °C/W. It is also found that, as the main factor to the the thermal performance of the collector, thermal resistance of the PHP absorber decreases with increasing evaporation temperature. The collector apparently shows start-up, operational and shutdown stages at the starting and ending temperatures of 75 °C. When the direct normal irradiance is 800 W/m2, the instantaneous thermal efficiency of the solar collector can reach up to 50%.The work was financially supported by the National Natural Science Foundation of China (51506004), Beijing Natural Science Foundation (3162009), Scientific Research Project of Beijing Educational Committee (KM201410016001) and Research Fund of Beijing University of Civil Engineering and Architecture

Induction of resistance in cucumber against seedling damping-off by plant growth-promoting rhizobacteria (PGPR) Bacillus megaterium strain L8

Bacillus megaterium L8, a plant growth-promoting rhizobacterium (PGPR), was isolated and evaluated for its ability to induce resistance in cucumber against seedling damping-off caused by Pythium aphanidermatum. Root-splitting challenge experiments showed that L8 treatment of cucumber roots more effectively suppressed seedling damping-off than did the control as judged by seedling survival rate (83.45 versus 31.68% at 28 days), indicating that strain L8 is capable of inducing systemic disease resistance in cucumber. To explore the potential mechanism underlying the induced systemic resistance (ISR) mediated by L8, the expression profile of several plant defense-related enzymes: superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) were monitored in the roots treated with L8 or P. aphanidermatum and untreated leaves in a time course of 13 days. Levels of SOD, POD, CAT, PPO and PAL activities in the treated roots and untreated leaves of cucumber seedlings were all significantly higher as compared with the control and respectively peaked in the roots at 3, 3, 5, 5 and 5 days and correspondingly in the leaves at 5, 3, 5, 5 and 5 days post-inoculation. The enhanced expression patterns of the above enzymes following L8 or P. aphanidermatum treatment suggested that systemic induction of plant defense enzymes by L8 might account for its ability to provide effective protection for cucumber from seedling damping-off caused by the soil-borne fungal pathogen P. aphanidermatum.Key words: Plant growth-promoting rhizobacteria (PGPR), defense enzymes, damping-off of cucumber seedlings, induced resistance

The effect of thermal annealing on the properties of indium tin oxide thin films

ITO thin films were deposited on glass substrates using e-beam evaporation. The influence of post-deposition annealing on the optical properties of the films was investigated in detail. It was found that the annealing conditions strongly affect the optical properties of the films. The transmittance of films annealed in forming gas (mixed 80% N 2 and H 2) at first increases dramatically with increasing annealing temperatures up to 300°C but then drops for higher temperature anneals around 400°C. An interesting phenomenon is that the transmittance of the darkened film can recover under further 400°C annealing in air. Atomic force microscopy, X-ray diffraction and X-ray photoemission spectroscopy have been employed to obtain information on the chemical state and crystallization of the films. Analysis of this data suggests that incorporation and decomposition reactions of oxygen can be controlled to reversibly change the optical properties of the ITO thin film. © 2005 IEEE.published_or_final_versio

Influence of gaseous annealing environment on the properties of indium-tin-oxide thin films

The influence of postannealing in different gaseous environments on the optical properties of indiu-tin-oxide (ITO) thin films deposited on glass substrates using e-beam evaporation has been systematically investigated. It is found that the annealing conditions affect the optical and electrical properties of the films. Atomic force microscopy, x-ray diffraction, and x-ray photoemission spectroscopy (XPS) were employed to obtain information on the chemical state and crystallization of the films. These data suggest that the chemical states and surface morphology of the ITO film are strongly influenced by the gaseous environment during the annealing process. The XPS data indicate that the observed variations in the optical transmittance can be explained by oxygen incorporation into the film, decomposition of the indium oxide phases, as well as the removal of metallic In. © 2005 American Institute of Physics.published_or_final_versio

The effect of Ga-doped nanocrystalline ZnO electrode on deep-ultraviolet enhanced GaN photodetector

published_or_final_versio

Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of AuGaN Schottky contacts

Under identical preparation conditions, AuGaN Schottky contacts were prepared on two kinds of GaN epilayers with significantly different background electron concentrations and mobility as well as yellow emission intensities. Current-voltage (I-V) and variable-frequency capacitance-voltage (C-V) characteristics show that the Schottky contacts on the GaN epilayer with a higher background carrier concentration and strong yellow emission exhibit anomalous reverse-bias I-V and C-V characteristics. This is attributed to the presence of deep level centers. Theoretical simulation of the low-frequency C-V curves leads to a determination of the density and energy level position of the deep centers. © 2006 American Institute of Physics.published_or_final_versio

Effects of annealing temperature on the characteristics of Ga-doped ZnO film metal-semiconductor-metal ultraviolet photodetectors

published_or_final_versio

Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of Au/GaN Schottky contacts

Author name used in this publication: X. M. Tao2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe