Һ����Ȼ�����о���չ�����������̽��

随着对清洁能源需求量的日益增长,天然气国际贸易量正在不断加大。远隔重洋地区的天然气贸易是依靠将天然气液化后通过船运来完成的,因而LNG船就成为了完成天然气远洋贸易的关键设备。文章回顾了LNG船的发展史,介绍了LNG船的技术特点和一些配套设施,同时还阐述了我国需要建立自己的LNG船队,从而保证我国LNG进口的重要意义。     

Demand-side management impact on the transmission and distributionsystem

A project to assess the impact on the transmission and distribution (TD) system due to the implementation of demand-side management (DSM) programs is described. Traditional TD planning methods are reviewed and procedural changes necessary to fully integrate DSM strategy analysis with the system planning process are discussed. Test procedures and results are discussed for a study conducted at a host utility. Several DSM strategies are analyzed to assess the impacts on a TD system serving a large metropolitan area     

Low-frequency noise behavior of 0.15-μm gate-lengthlattice-matched and lattice-mismatched MODFETs on InP substrates

Experimental data are presented on equivalent gate noise voltage from 1 to 10⁵ Hz obtained from lattice-matched and strained InGaAs quantum-well modulation-doped field effect transistors (MODFETs). In both types of devices excess generation-recombination (g-r) noise is observed at or below 100 Hz above an `apparent' background 1/f noise with spectral intensity ranging from 0.5×10^-17 to 2×10^-17 V²-Hz^-1-cm² at 1 Hz. These results are comparable to those reported by S.M.J. Liu et al. (1986) for the pseudomorphic MODFETs     

Invention from War: a circumstantial modernism for Australian architecture

Between 1942 and 1945, Australian architects and engineers within the Allied Works Council and the US Army Corps of Engineers undertook a vast programme of building works to assist the campaign to drive Japanese forces northward through the Southwest Pacific and avoid invasion.¹ Huge distances, lack of time and the need to wage a campaign from the air lay behind US General Douglas Macarthur's phrase that it would be an 'engineer's war'. By necessity, buildings such as airfields, hospitals, camps, warehouses, and other structures had to be light weight, constructed quickly, and inevitably dropped in by air as easily handled pre-cut packages. With the lack of American and European softwoods in the Australasian region, an unlikely local material was pressed into war service - unseasoned or 'green' Australian hardwood. It was a material choice that would have profound implications for two reasons. First, in the years of conflict, circumstances dictated the unprecedented innovation and experiment in light-weight timber structures. Second, in an echo of Lewis Mumford's poignant maxim that 'war is the health of the machine'², the systematisation and ruthless economy inherent in wartime timber buildings would influence the development and practice of a particular form of modern architecture in Australia in the late 1940s and the 1950s.     

Explosive vapor bubble growth in uniformly superheated liquids: R-113 and mercury

Based on experimental and analytical work conducted previously with R-113, the results of an analytical study of the vapor bubble dynamics for mercury associated with nucleation and growth are presented here. The simulations show that a growing mercury vapor bubble can be substantially unstable under sufficiently high superheat, as with a superheat level of 100 °C, and that surface tension tends to stabilize the process. At a superheat level of 30 °C, the growth is marginally stable due to the high surface tension, and quite stable in the very early stages of the growth. For most cases, the wavelength of growing perturbations appear to be relatively large compared to that for water, again due to the large surface tension of mercury. As a result of the high liquid-to-vapor density ratio, the growth rates of mercury vapor bubbles can be quite high, reaching a diameter of 1 m in 1 s, with an initial superheat of 100 °C and pressure of 0.1 atm. The effects of system pressure are also considered here.     

Picosecond mid-IR laser induced surface damage on Gallium Phosphate (GaP) and Calcium Fluoride(CaF<Subscript>2</Subscript>)

Picosecond mid-IR USPL induced surface damage on a Gallium Phosphate (GaP) and Calcium Fluoride (CaF₂) is reported. A semiconductor GaP and a dielectric material CaF₂, that are transparent over3–10μm, were exposed to one picosecond mid-IR light (4.7μm) to investigate laser-induced surface morphological changes on the target The initiation of damage along the polishing scratch line of GaP and the random location of damage digs on the CaF₂ suggests that the mid-IR picosecond laser-induced damage on targets started from intrinsic surface defects. Multiple pulse irradiations produced periodic corrugated surface structures (ripples) perpendicular to the polarization of light on both GaP and CaF₂. In terms of the orientation and the spacing between ripples, observed ripples have common features with previously reported ripples.