Effects of surface adsorbed oxygen, applied voltage, and temperature on UV photoresponse of ZnO nanorods

The ultraviolet（UV） photoresponses of ZnO nanorods directly grown on and between two micro Au-electrodes by using electric-field-assisted wet chemical method are measured comprehensively under different conditions, including ambient environment, applied bias voltage, gate voltage and temperature. Experimental results indicate that the photoresponses of the ZnO nanorods can be modulated by surface oxygen adsorptions, applied voltages, as well as temperatures. A model taking into account both surface adsorbed oxygen and electron-hole activities inside ZnO nanorods is proposed. The enhancement effect of the bias voltage on photoresponse is also analyzed. Experimental results shows that the UV response time（to 63%） of ZnO nanorods in air and at 59°C could be shortened from 34.8 s to 0.24 s with a bias of 4 V applied between anode and cathode.

Effective Field Theory Techniques Applied to the Properties of the Axion

We utilize the effective field theory approach to study the properties of the axion. In particular, with s as well as u and d quarks regarded to be relatively light we derive a formula for the mass of the axion; a rough estimate of the rate for its dominant decay mode at low energy is also carried out.

Research on the New Technology and System of Ultrasonic Honing

In recent years, the new technology of ultrasonic vibration cutting has been drawing general attention. And great advancement in theory and applications in production of the technology have been achieved. Ultrasonic vibration honing system developed in North China Institute of Technology and Nanjing University of Aeronautics and Astronautics of cast iron cylinder (47×97) and thin cylinder of 20# (86×95) has been successfully applied to productive experiment and the technological effect obtained is ideal. In comparison with ordinary honing, ultrasonic vibration honing possesses apparent characteristics: Firstly, it has high processing precision (precision in size ranks IT6, roughness Ra0.05, circularty and cylindericity in size ranks IT6); Secondly, it has small cutting force and low temperature so that no deformation occurs; Thirdly, it has high efficiency. In this paper, the application of a new technique to honing is introduced, and the ultrasonic honing systems of thin cylinder and cast cylinder which have been successfully manufactured and their applying effect are illustrated. This paper analyzes the cutting principle of ultrasonic honing in terms of cutting motion, grain performance and cutting quantity. The study of this technique starts a new approach to which is efficient higher quality and lower consumption to hole’s precise and superprecise machining. At last,the paper introduce the conclution: Ultrasonic honing sharpens grain, which is favorable for raising cutting efficiency; Ultrasonic vibration honing may increase honing depth and raise cutting efficiency. It may also decrease honing power and system deformation; Undergoing practice we can find that the ultrasonic honing system as above discribed can be extended and applied to production. The system not only can be applied to conventional honing machine, its technology effect as good as high precision machine tool, but also can be applied to develop and study ultrasonic vibrating numbrical controlling honing machine tool which will provide a new type, efficient, high quality low consumption, equipment for working precision hole; Appling the same parament as W40 oilstone bar, under the same condition, is very valuable for product and application. Rough machining and finish machining once time finished, which not only improve location accuracy, but also have a high effiency.The honing system not only can be suitable for honing cast cylinder, but also can be applied for honing engineer ceramics as well as hard, crisp material; The dimension and technology paraments of 47 mm honing system as above discribed, can be suitable for honing the cast cylinder of motorcycle or minicar. And the cylinder diameter can be randomly selected from 45 to 65. The dimension and technology paramagnets of 86 honing system as above discribed,can be applied for honing all kinds of cylinder of light or heavy passenger-cargo vehicle, and the cylinder diameter can be randomly selected from 65 to 100; It is easy to achieve new technology of flat roof honing by applying ultrasonic honing.After the flat roof honing, fuel consumption of engine is 1g/Hp, while conventional engine is 3g/Hp.Life expectancy of engine is prolonged greatly after the cylinder by flat roof honing.