Search

Taking Chizhou City, which was located in the southwest of Anhui Province as the test area, test points were selected to observe and compare the temperature and dust retention effects of different vegetation types. The methods of the study: The temperature is measured by a combination of manual measurement and self-calculating thermometer. By using the formula "dust reduction rate = (dust content of dust source-dust content of green space) / dust content of dust source", calculate the dust reduction rate, and analyze the data. The results of the study showed that urban green space had obvious cooling and dust retention effects. In terms of air temperature, the variation range of bare land was the largest, followed by that of grassland, and that of shrub and herbaceous vegetation was small, while temperature variation range of shrub and herbaceous vegetation with arbors was the smallest, and this kind of vegetation arrangement had the strongest ability to adjust temperature and the best cooling effect. In terms of dust retention, the effect of the shrub and herbaceous vegetation with arbors was the best, followed by shrub and herbaceous vegetation and grassland, and the results also showed that the dust retention effect of the road green space was better than that of the park green space and the residential green space. The result of the study is that: The Trees, shrubs and herbs has the greatest ability to regulate temperature, with a difference of 3 to 7 °C. The temperature adjustment range of Shrubs and herbs is 2~3 °C; all the urban green space of different vegetation types has the effect of cooling and dust retention. The cooling and dust retention effects of different vegetation types were studied in order to provide some theoretical basis for the planning and construction of urban green space.

The effects of oxygen plasma treatment on the surface properties of indium-tin-oxide (ITO) anodes and its ageing were investigated by chemical composition and work function measurements. We found that oxygen plasma treatment optimized the chemical composition and increased the work function, and thereby improved the surface properties of ITO. Yet such an improvement in the surface properties of ITO anodes due to oxygen plasma decayed with the increment of storage time after treatment. Furthermore, we studied the effect of ageing variation of surface properties of treated ITO anodes on the performance of organic light-emitting devices (OLEDs), in terms of the electroluminescence lifetime, efficiency, luminance and driving voltage. Experimental results reveal that the device performance of the OLEDs tends to become worse as the storage time increases. The performance of the device fabricated with treated ITO at 21 h after storage is almost the same as that of the untreated ITO. We suggest that the ITO substrates for OLEDs should be retreated by oxygen plasma treatment 21 h after storage. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In this paper we have derived the generalized QNLS equation with considering the third-order dispersion and Kerr dispersion, which can be applicable to the femtosecond regime and is suitable for discussing the quantum properties of femtosecond solitons in single-mode optical fibers, as compared with its classical counterpart. This quantum operator equation can be solved by many methods such as the linearized perturbations and phase-space methods. Moreover, owing to the fact that this quantum equation is rather similar to its classical counterpart, all these methods can be facilitated to a great extent by citing correctly the classical results obtained before.

In this paper, a limited-view optical tomography technique is presented, which contains an orthographic holography system, an image processing system and the simultaneous algebraic reconstruction technique (SART). Using this technique, the temperature field of a cross section in the flow of hot air from a nozzle is measured. The measured results are satisfactory.

An (AB)N(BA)N-type one-dimensional photonic crystal is made from common material A(SiO2) and electric single-negative material B. Numerical calculation results indicate that there is a very sharp tunneling model at 1907.3 nm of the original band. When the incident angle increases, the transmittance and the full-width half-maximum of the tunneling mode remains the same, but its position is blue shifted. The value of |d/d| turns larger when the incident angel is in a range from 15 to 65. When permeability of B medium B increases from 5 to 10, the position of the tunneling model is only red shifted. When geometric thickness of the dielectric increases, the transmittance of the tunneling model remains unchanged, but its position is red shifted obviously and its full-width half-maximum increase slightly.