Coexistence of superconductivity and ferromagnetism in La1.85Sr0.15CuO4-La2/3Sr1/3MnO3 matrix composites

In order to clarify the interaction between superconductivity and magnetism, a series of (La_1.85Sr_0.15CuO₄)_1−x (La_2/3Sr_1/3MnO₃)_x matrix composites (x = 0-0.2, mole fraction) was successfully prepared by solid-state reaction method. Based on the electrical transport measurements, it is found that the superconductivity is gradually suppressed as increasing the content of La_2/3Sr_1/3MnO₃ (LSMO) manganites and that the superconductivity still exists in the composites even though plenty of LSMO is introduced into La_1.85Sr_0.15CuO₄ (LSCO) superconducting cuprate. At the same time, the results of the magnetic measurements also demonstrate the coexistence between superconductivity and ferromagnetism when the CuO₂ planes are intact as follows from the results of X-ray diffraction (XRD). In the whole, the present experiments show that the ferromagnetism in the microscale does not destroy superconductivity for LSCO cuprate in this kind of the matrix composites, and the intercalation of LSMO may lead to an electronic phase separation in LSCO with the hole rich and/or hole poor regions.     

滕县煤田红层微观赋存与水-岩作用研究

滕县煤田红层作为煤层的间接充水水源,对煤矿的安全开采形成了一定的威胁,该文综合大量的勘探资料,并利用对典型钻孔试样进行化学成分、矿物成分、微观形态的分析测试,揭示了红层的赋存特征及水—岩作用规律,为有效地防治红层水提供了理论依据。     

对氯苯异氰酸酯的合成

以对氯苯胺和三光气为原料，合成对氯苯异氰酸酯。通过考察溶剂、反应时间、原料摩尔比、反应温度和缚酸剂等因素的影响，获得了最佳反应条件，收率可达81％。     

基于PLC的XA6132型卧式万能铣床改造

文中对三菱可编程序控制器（PLC）应用于XA6132型卧式万能铣床电气控制系统的改造作了介绍,对系统的硬件组成和软件设计进行了阐述.实践证明,在应用PLC进行技术改造后,该控制系统的硬件电路得到了简化,工作更加可靠,提高了机床工作效率.     

高速铁路客运站内空间组织优化设计研究

本文引入空间句法的理论方法,通过理论研究与实例分析相结合的方式,对高速铁路客运站的内部空间组织进行研究。提取空间句法中的连接值、集成度和智能值这三个评价指标来量化分析空间的可达性和可理解性,完成了对高速铁路客运站内部空间组织的定量性评价和优化,改变了以往单凭经验设计造成的偏差,提出了高速铁路客运站空间组织设计的方法。     

Influence of division cone angles between the fuel-rich and the fuel-lean ducts on gas–particle flow and combustion near swirl burners

Radial bias combustion pulverized coal swirl burners are used in boilers when burning low-grade coals, which are often low-volatility anthracite and lean coals that do not burn stably. In a gas–particle test facility, a three-dimensional particle-dynamics anemometer was used to measure gas–particle flows in the near-burner region. Division cones between the fuel-rich and the fuel-lean ducts of the burner were set at angles of 43.2° and 0°. Velocity and particle volume flux profiles were obtained and the influence of the cones on combustion was analyzed. Burners with a division cone angle of 43.2° were used in a lean-coal fired boiler (volatility 13.2% as received, ash 27.46% as received), rated at 670 t/h. Pulverized coal was conveyed by cold moisture-laden exhaust air from the pulverizer. In situ aerodynamic field measurements in cold state were made and combustion tests were carried out. Low NO_x emission and high thermal efficiency resulted and the turn-down ratio was 50%.     

基于双门限能量检测的自适应协作频谱感知

针对认知无线电中传统单门限能量检测由于单一门限造成的低信噪比情况下容易误判从而导致错失频谱接入机会的不足,提出了一种基于双门限能量检测方法的自适应协作频谱感知模型.该模型以加性高斯白噪声信道模型为基础,由传统双门限能量检测方法改进而成,针对接收到的能量统计值的大小采用不同的判决方法,各个判决结果直接由所采用的判决方法决定.仿真结果表明,在较低信噪比条件下,与传统单门限能量检测模型相比,该自适应协作频谱感知模型具有更好的识别性能,随着用户数量的增加,识别性能更优.     

Experimental study of the combustion efficiency and formation of NOx in an industrial pulverized coal combustor

With horizontal bias combustion burners, experiments have been carried out on a 670 t h^?1, corner‐fired, pulverized‐coal fired boiler burning bituminous coal. At 200 MWe load, the furnace excess O₂ remains stable. The different horizontal fuel biases are obtained by changing the tilt angle of all the Louvre enrichers' regulating blades. The tilt angles of the blades are 0, 15, 24, 32°; the result is that the enriching ratios of the fuel‐rich primary air increase from 2.2 to 2.6 at No. 2 corner, and from 1.2 to 4.2 at No. 3 corner. The gas temperature increases in the burner region. The application of the horizontal bias combustion burners results in a reduction in NO_x formation from 545.7 mg Nm^?3 (O₂=6%) to 287.9 mg Nm^?3, and a substantial reduction in carbon in ash content from 5.24 to 2.48%. The boiler operated stably at a load of 80 MWe without auxiliary fuel oil. Copyright © 2004 John Wiley & Sons, Ltd.     

当代生态建筑的美学新模式

生态建筑是当代先锋建筑中独具特色的一个分支，在美学模式上已突破以工业文明为基础的现代主义原则，汲取了哲学、美学、生态学等学科的基本原理。透过当前剧烈变动的建筑美学发展动向，分析了当代生态建筑潜在的意义与美学价值，侧重的不是提供某种创作手法，而在于能展现一些新的艺术模式和在新的艺术模式影响下的建筑现象，并对当代生态建筑美学观念的作品体现进行了合乎当代文化语境的解释。     

MAK-Ⅱ和СГДT-HB测井仪在辽河油田的应用

MAK-Ⅱ仪器和СГДТ-НВ仪器是从俄罗斯引进的测井仪器。MAK-Ⅱ仪器又称声波水泥胶结测井仪器,它用于评价套管井水泥胶结质量;СГДТ-НВ仪器又称伽马密度-套管壁厚度测井仪,它是一种用放射性方法检测水泥胶结质量和套管技术状况的仪器。简单介绍了MAK-Ⅱ仪器和СГДТ-НВ仪器的测井原理及解释方法,着重阐述MAK-Ⅱ和СГДТ-НВ测井仪器在辽河油田的应用情况。