用焦渣沸腾燃烧系统中的灰为热载体进行动力煤的热分解

在石油及天然气短缺并不断增涨价格的情况下,世界上对于发展煤的动力化学加工新方法增加了注意;这尤其涉及到煤贮量大而石油及天然气少的国家(西德、波兰)。现今,在燃料——动力平衡中增加煤的比例,已成为许多国家在近期和远期国民经济增长的重要因素之一。研究煤的动力化学加工新方法,在许多国家,其中如美国和波兰,已列入国家研究发展规划之内。波兰现在已经出现的液体和气体燃料     

全球电子废物的研究(中)

(续接本刊2007年第7期第36页)2电子废物管理方式和立法提案2.1延伸生产者责任制延伸生产者责任制(EPR)作为废物管理的新模式得以广泛推广。OECD将EPR定义为一种新的环境制度,在该制度下,生产者对其产品的责任延伸到产品销售后的整个生命周期,包括最终处置(OECD,2001)。与污染者付费原则一致,     

Degree of polarization estimation in the presence of nonuniform illumination and additive Gaussian noise

Within the general framework of active imaging we address the degree of polarization (DOP) estimation in the presence of additive Gaussian detector noise. We first study the performance of standard DOP estimators and propose a method to increase estimation precision using physically relevant a priori information. We then consider the realistic case of nonuniform illumination distribution. We derive the Cramer-Rao lower bound and determine a profile likelihood-based estimator. We demonstrate the efficiency of this new estimator and compare its performance with other standard estimators as a function of the degree of nonuniformity of the illumination.     

Epitaxial integration of the highly spin-polarized ferromagnetic semiconductor EuO with silicon and GaN

Doped EuO is an attractive material for the fabrication of proof-of-concept spintronic devices. Yet for decades its use has been hindered by its instability in air and the difficulty of preparing and patterning high-quality thin films. Here, we establish EuO as the pre-eminent material for the direct integration of a carrier-concentration-matched half-metal with the long-spin-lifetime semiconductors silicon and GaN, using methods that transcend these difficulties. Andreev reflection measurements reveal that the spin polarization in doped epitaxial EuO films exceeds 90%, demonstrating that EuO is a half-metal even when highly doped. Furthermore, EuO is epitaxially integrated with silicon and GaN. These results demonstrate the high potential of EuO for spintronic devices.     

基于集中参数模型的HOFFELL低温地热田热储模拟与评价

低温地热田热储研究有利于地热资源的开发与利用。通过介绍以供暖为主要目的的冰岛Hoffell低温地热田地质概况、地热地质特征、地热系统概念模型和资源潜力,论述了集中参数模型的实现原理和数学基础。基于201d的开采试验和集中参数模型,模拟了热储水位在开采过程中的响应。模拟结果表明,集中参数模型中的双容器封闭模型和双容器开放模型模拟的水位拟合度较高,分别为98.7%和99.3%,并进一步采用以上两种模式,预测了热储水位在四种开采流量(28.6、21.4、14.3、7.15L/s)下稳定开采10年的变化趋势。研究成果对我国中低温地热资源的开发利用有一定的借鉴意义。     

A Scheduling Policy of Short Video Clips for VoD Systems Based on Optical Jukeboxes

1　IntroductionVideo on Demand (VoD)isapromisinginter activemultimediaapplicationthatiscapableofhand ingbothlongvideoprograms,suchasmovies,andshortvideoclips,e.g .news.MuchofpreviousstudiesofVoDsystemsweremainlyfocusedonlongprogramapplicationssuchasmovie on de mand[1～2 ] .Butshortvideoclipscanbemorepreva lentinapplicationslikedigitallibrary ,news on de mandandelectroniccommercewhereavideocliponlylasts 2 - 3minutes[3～4] .StudiesofVoDsys temsforshortclipsareofsignificanceforthatkindofapplic…     

制氧工问题浅解

1．问:2．5型制氩装置粗氩纯度达不到,是什么原因?答:配 KFS－860－1型空分设备的制氩装置(YF－2．5型)都是经过试车检验,产品合格后出厂的。一般在配上空分设备后,都能正常运转,但由于运输、安装、操作等各种原因,调试时,粗氩纯度可能达不到要求,引起的原因很多,主要有以下几点:     

小型空分设备增产,提纯及其节能的方式方法

一、综述我国自1953年试制成功第一套30m~3/h(氧)的小型空分设备以来。由本行业各厂家生产的各类空分设备、气体液化设备以及天然气石油分离设备等已有102个品种,截止到1987年底,我国已拥有空分设备总量为3646套,其中20—800m~3/h(氧)的小型空分设备为3159套,制氧能力为1914845m~3/h,其单位制氧能耗设计值为1.2—1.6kw.h/m~3O_2,而实际运转值高达1.7—1.96,有的甚至超过2,差不多高出设计值的20％左右。     

W/C, W/Ti, Ni/Ti, and Ni/V Multilayers for the Soft-X-ray Range: Experimental Investigation with Synchrotron Radiation

An experimental investigation of W/C, W/Ti, Ni/Ti, and Ni/V multilayers is presented that uses synchrotron radiation in the soft-x-ray energy region between 100 and 1500 eV with special emphasison the water window. The multilayers were designed as normal incidence reflectors and for polarimetry purposes around the Brewster angle. Both reflection and transmission multilayers were prepared for use as linear polarizers and phase retarders, respectively, to produce or analyze circularly polarized light. Their period was optimized to achieve maximum reflectance at the 1s absorption edge of C (284 eV) and the 2p edges of Ti (454 eV) and V (512 eV), respectively. At these edges the multilayers show an enhancement of reflectance and energy resolution that is in accordance with theoretical calculations.     

建设“三型”马克思主义执政党的思考

每个时代总有属于它自己的问题,问题是时代的声音,只有树立强烈的问题意识,才能实事求是地对待问题,才能找到引领时代进步的路标。从“建设一个什么样的党,怎样建设党”到“为什要建设学习型政党,怎样建设学习型政党”再到十八大提出“建设学习型、服务型、创新型的马克思主义执政党”,是我们党在理论与实践上提出的重大理论和现实问题。因此,“三型”执政党的提出及其建设目标问题的确定是深深植根于自己所处的时代,回应自己所要解答的时代问题。