电-声相互作用对金属氢磁性的影响

本文运用Hirsch的自旋—极化铁磁理论,并考虑了电—声相互作用对单中心、双中心以及电子有效质量的修正后,讨论了金属氢在T=OK时的自发磁化强度随晶体的Wigner-Seitz半径r_(s)的变化。结果指出:金属氢的自发磁化强度m_(s)≠0的区域随参数P的增大而收缩,但m_(s)的值不一定比未考虑电—声相互作用时的值小。     

汤河水库雷达监测站防雷改造措施

本篇文章首先介绍了汤河水库概况和雷达监控系统的建立背景和系统组成,随后分析了汤河水库雷达监测站设备曾经多次遭遇雷击的现象以及产生的问题和原因,详细研究现有防雷系统组成和安装情况,针对存在的问题进行防雷系统改建的设计和具体措施,从而实现保护设备安全运行和提高水库整体水质的目的。     

Attachment in the Classroom

Attachment influences students’ school success. This is true of students’ attachment to their parents, as well as to their teachers. Secure attachment is associated with higher grades and standardized test scores compared to insecure attachment. Secure attachment is also associated with greater emotional regulation, social competence, and willingness to take on challenges, and with lower levels of ADHD and delinquency, each of which in turn is associated with higher achievement. These effects tend to be stronger for high-risk students. In this era of accountability, enhancing teacher–student relationships is not merely an add-on, but rather is fundamental to raising achievement. Understanding the role of attachment in the classroom will help educators be more effective, particularly with challenging students. Twelve suggestions to improve teacher–student relationships and school bonding are provided.     

Analysis of dipole-like ultra high frequency RFID tags close to metallic surfaces

It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas, such as the impedance matching, the radiation efficiency and the radiation pattern, are seriously affected by the metallic surface. This paper presents the characteristics of the dipole-like antennas of ultra high frequency （UHF） radio frequency identification （RFID） tags that are placed close to metallic surfaces. The finite element method （FEM） and method of moment （MoM） were used to simulate the changes of the antenna parameters near the metallic surface. Two typical dipole-like antennas close to the metallic surface, a closed loop antenna and a loaded meander antenna, were modeled, and the performance was evaluated. Experiment was carried out and the results were in good agreement with the simulation, showing that a distance of 0.05λ-0.1λ （λ is the free space wavelength） from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable.     

用有限元方法分析玻璃载芯片封装中的热力耦合问题

超薄液晶显示器(LCD)模块在经历了热压键合后,由于驱动芯片和玻璃基板之间的温度差异较大,会引起一定程度上的翘曲,并最终导致连接点界面分层现象的发生,影响器件连接可靠性。用实验的方法对比进行研究比较困难,我们用有限元数值模拟的方法并选择通用软件ANSYS对这一现象进行了分析;并详细分析了键合压力、温度、基板温度和IC/玻璃厚度对翘曲的影响。从分析中得知,导致玻璃翘曲的主要原因是键合温度。     

Enamel insert restorations on Limoges painted enamels: A study on a remarkable nineteenth-century restoration technique with particular attention to the original paillon designs

Two sixteenth-century Limoges painted enamel plaques by Léonard Limosin in the collection of the J. Paul Getty Museum, Los Angeles, show a remarkable restoration technique consisting of separately enameled pieces that have been inserted into areas where original enamel was lost. A detailed investigation of the two plaques brought information about this former restoration method and the materials used. Investigation included optical microscopy, UV-A examination, and X-radiography for identification and mapping of the insert restorations, scanning electron microscopy with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and gas chromatography-mass spectroscopy for analyzing organic restoration material as well as X-ray fluorescence for studying the enamel compositions. A survey of six other Limoges painted enamel collections in the USA was carried out, which revealed many more of these insert restorations and indicated particular damages related to the so-called paillon designs on silver or gold foils. A literature review was undertaken focusing on possible causes of the damage as well as on persons and workshops that may have executed the insert restorations.     

冲击对泵浦激光器反馈片紫外胶连接性能的影响

通过试制样品的有功率性能测试和无功率性能测试的冲击实验,分析了超小型泵浦激光器反馈片紫外胶连接抗冲击性能影响因素,结果表明,样品外壳冲击变形的局部应力导致反馈片胶连接产生冲击裂纹损伤;样品冲击后的功率一电流一温度（P一,一T）性能测试的热胀冷缩产生热应力,促进了胶连接内亚裂纹扩展并形成了絮状纹,且促进反馈片胶连接冲击裂纹扩展并成为新的裂纹生长的潜在因素,劣化了胶连接性能．     

浅谈建筑物的等电位联结

阐述建筑物的等电位联结的概念、分类、安装及它对用电安全、防雷以及电子信息设备的正常工作和安全使用的必要性,针对现实问题提出解决问题的建议和措施。