地下硐室锚喷支护堵漏防渗处理实践

本文简要地介绍了我国几个地下矿在锚喷网联合支护的硐室工程中堵漏防渗处理所取得的良好效果，可供类似矿山参考。     

Dislocations and flux pinning in YBa2Cu3O7

The dislocation structures of bulk textured and epitaxial thin film YBa₂Cu₃O₇ superconductors are examined. Correlations between increases in flux pinning and dislocation densities are noted. A model for flux pinning by individual dislocations is presented. This gives a treatment of strain induced effects and effects of normal state region interactions. It is shown that the values of pinning predicted are in line with experimental observations.     

Evaluation of influence of external magnetic disturbance on superconducting magnet taking conservation of linkage flux into account

External magnetic disturbance influences the quality of the image obtained with a magnetic resonance imaging (MRI) system because it causes magnetic resonance frequency drift. When a superconducting magnet in persistent current mode operation is exposed to external magnetic disturbance coil current varies to keep linkage flux constant. Conventional analysis is usually formulated with constant current and does not provide correct evaluation of drift of magnetic field in the magnet. This paper proposes a method of numerical analysis of magnetic field considering conservation of linkage flux in a superconducting magnet under a persistent current mode operation. This method is applied to evaluate drift of the magnetic field in a superconducting magnet for magnetic resonance imaging due to external magnetic disturbance. Analysis results show good agreement with the experimental results.     

新型并条胶辊套筒的特点及运用

为了解决常规并条胶辊套筒存在的易发热、易漏油，芯轴易弯曲磨损以及保养、能耗等问题，介绍了新型免加油并条胶辊套筒的性能特点并以实际生产数据进行对比；说明实际使用该新型并条胶辊套筒综合效果好，具有省工省时、降低消耗、质量稳定、使用寿命长、总投资少等优点。     

三峡永久船闸结构缝渗漏处理技术

在三峡永久船闸结构缝处理过程中，认真分析了结构缝渗漏的原因，通过止水检查槽进行压水检查，确定了渗漏部位。结合渗漏具体情况，采取了结构缝表面嵌填止水材料和廊道周边止水检查槽灌浆相结合的处理方法。在实施过程中，采用了多种新材料和新工艺，取得了良好的效果。     

TOPSwitch集成电路在DC/DC电源设计中的应用

文章介绍了PWM／MOSFET二合一的TOPSwitch系列集成电路及其在DC／DC电源设计中的应用，还介绍了基本反馈方式的DC／DC拓扑结构及其改进措施，并对由TOPSwitch集成电路构成的DC／DC电源进行了抗中子实验。     

Synthesis of Nearly Monodisperse Iron Oxide and Oxyhydroxide Nanocrystals

Uniform magnetite, hematite, and goethite nanocrystals were prepared through an attractive method based on an oleic acid/alcohol/water system. By adjusting the synthetic parameters (base concentration, alcohol content, categories of alcohols, etc.), the controlled synthesis of uniform magnetite, hematite, and goethite nanocrystals can be easily achieved. Detailed investigations on the effect of the experimental parameters on the morphology of the final products and the phase transitions among the magnetite, hematite, and goethite phases were carried out. Finally, a method of doping other metal ions into magnetite was developed and the magnetic properties of magnetite doped with different metal elements were studied.     

求解电缆自感系数的一个佯谬

用求自感系数的两个常用公式求解实心电缆自感系数时，如果不注意对公式中Φm及I的正确理解，将会得到不一致的“佯谬”结果。本文通过将实心电缆等效为许多细线圈的方法，用2种公式求解得到了一致的结果。     

流场拟合法在缩微环境中的研究

流场拟合法是由何继善院士提出的物理探测技术。以流场拟合法为理论基础研制的管涌渗漏检测仪在堤坝检测及抗洪抢险中发挥了重要作用，本文提出了一种在缩微环境中模拟管涌渗漏，对流场拟合法进行模拟测试并获得了明显的结果。为管涌仪器的性能检测、校验、标定提供了便捷的测试方法，并为该仪器在生产过程中统一性能和企业标准的制订提供了理论依据。     

某供用电综合楼地下基础底板堵漏防水技术

结合工程概况，分析了负二层地下基础底板渗漏的原因，介绍了防水堵漏方案的设计与优选以及主要施工工艺，实践证明，该工程堵漏防水技术可靠，效果良好，保证了工程的顺利进行。