利用旋转流动提高冷却塔汽水回收效率的实验研究

本文介绍了一种可广泛应用的旋转流动汽水回收原理性实验研究,与传统的波纹板汽水回收方法相比较,旋流流动收水方法通过改变气(汽)流的上升流动为旋转上升流动,利用离心力将气流中的颗粒状水滴直接甩到器壁回收,保证湿空气基本均能够与壁面接触并且增大湿空气与壁面的接触时间,在接触旋转流动过程中使湿空气中的水蒸汽尽可能多地凝结成水滴回收。通过实验研究,旋转流动收水方法能达到比较理想的收水效果,收水效率相比较具有很大程度的提高。通过与现有波纹收水方法收水性能的比较实验,其他指标与波纹收水方法相当的情况下,收水效率提高10％～20％。旋转流动汽水回收方法可广泛适用于冶金、石油、化工、动力、纺织、大型中央空调等几乎所有需要回收水节能的行业中。特别适合应用与火力发电厂的大型冷却塔。本方法具有广泛的应用价值和经济价值。特别

Traducciones al español de canciones de los Beatles (1963–1996)

460 pgs.

Time and space-resolved measurement of a gas-puff laser-plasma x-ray source

The dynamic interaction processes between a nano-second laser pulse and a gas-puff target, such as those of plasma formation, laser heating, and x-ray emission, have been investigated quantitatively. Time and space-resolved x-ray and optical measurement techniques were used in order to investigate time-resolved laser absorption and subsequent x-ray generation. Efficient absorption of the incident laser energy into the gas-puff target of 17%, 12%, 38%, and 91% for neon, argon, krypton, and xenon, respectively, was shown experimentally. It was found that the laser absorption starts and, simultaneously, soft x-ray emission occurs. The soft x-ray lasts much longer than the laser pulse due to the recombination. Temporal evolution of the soft x-ray emission region was analyzed by comparing the experimental results to the results of the model calculation, in which the laser light propagation through a gas-puff plasma was taken into account. (C) 2003 American Institute of Physics.

Electron acceleration by an intense short-pulse laser in underdense plasma

Electron acceleration from the interaction of an intense short-pulse laser with low density plasma is considered. The relation between direct electron acceleration within the laser pulse and that in the wake is investigated analytically. The magnitude and location of the ponderomotive-force-caused charge separation field with respect to that of the pulse determine the relative effectiveness of the two acceleration mechanisms. It is shown that there is an optimum condition for acceleration in the wake. Electron acceleration within the pulse dominates as the pulse becomes sufficiently short, and the latter directly drives and even traps the electrons. The latter can reach ultrahigh energies and can be extracted by impinging the pulse on a solid target. (C) 2003 American Institute of Physics.

Laser wakefield and self-modulation of driving pulse

A self-consistent theory of plasma response to a single laser beam is proposed. The driving pump is not viewed as invariant during its interaction with the plasmas. Its modulation by the plasmas has an obvious influence on the strength of the wakefield behind the pulse. This suggests that the compression of the low-intensity pulse by the plasmas might be a possible way to excite largae-amplitude wakefield. (C) 2003 American Institute of Physics.

Photon-photon scattering in a plasma channel

The Heisenberg-Euler correction due to photon-photon scattering, a still unverified quantum electrodynamics effect, on electromagnetic wave interaction inside a plasma channel is investigated theoretically. From a signal laser beam in the relativistic overdense plasma channel, photon-photon scattering can produce a detectable output beam of different frequency and polarization. (C) 2003 American Institute of Physics.