有机化合物极谱催化氢波研究进展

通过50多篇文献简要地综述了有机化合物极谱催化氢波的历史进程，其过去与现在的发展状况。并由此展望了催化氢波的发展前景。     

黑洞物理研究进展

在现代物理学中,黑洞是最错综复杂的物体之一。它们为类星体和其他活动星系核提供能量,也有助于透彻地理解量子引力。我们回顾一下黑洞的观测上的证据并简单地讨论它们的一些特性,也阐述了一些近年来涉及宇宙监督和黑洞熵统计起源的进展情况。     

LM317可调式集成稳压电源的设计

LM317系列芯片是目前应用较为灵活的集成稳压器,本文对由LM317构成可调式稳压电源的各部份电路组成、基本工作原理、器件的要求、电源保护功能等作了较为详细的介绍,给出了设计过程的基本理论及实测数据。     

A Novel Electromagnetic Bandgap Structure for Filter

Electromagnetic bandgap (EBG) materials are periodic structures capable of prohibiting the propagation of electromagnetic waves within a certain band of frequencies. This characteristic of EBG has wide application. The structures to be studied here are mainly planar EBG materials of two dimensions, which are periodic arrays of holes etched in the ground plane of a conventional microstrip line. EBG structures are calculated with finite-difference time-domain (FDTD) method in this paper. Technique of the perfectly matched layer is used for the absorption of electromagnetic waves in FDTD. The FDTD method is programmed with the blend of C^ and Matlab languages, which makes the program both simple and fast computing. A kind of new EBG structure is brought out through a lot of experiments and analyses. A filter with wide stop-band and another filter with two stop-bands are designed.     

A study on dynamic response of slopes under wave action using simulation tests

1. Introduction At present, the construction of large-scale reservoirworks has given rise to many large-scale reservoirareas, the stabilization of slopes in these reservoirdistricts will be influenced by water waves. Thecirculating hydraulic loading caused by the waveproduces a great force on the slope, and especiallyforms a vibration wave force on the boundary of water surface and the slope earth, and even breaks the water-soil interface, leading to the excess pore pressurechanging along diff…     

Na?ve Students’ Conceptual Development and Beliefs: The Need for Multiple Analyses to Determine what Contributes to Student Success in a University Introductory Physics Course

This research involved na?ve physics learners who were interested in majoring in science or engineering. In a semester-long quasi-experimental study, open-ended pretests and weekly interviews were used to analyse the progressive development of students’ conceptions relating to sound and wave motion. Semi-structured interviews were also conducted to elucidate: (1) how their conceptions developed from everyday conceptions to unclear scientific conceptions to scientific conceptions, and (2) their beliefs of physics knowledge. Despite efforts to enable these students to learn physics, the findings showed that only two out of ten students developed acceptable physics conceptions during the course that would enable them to pursue the subject to a higher level. Also, students’ conceptual development was found to be related to their cognitive understanding and to epistemological beliefs of physics. Therefore, to facilitate na?ve physics learners’ success in a general physics course, in addition to the acquisition of content knowledge, explicit emphasis needs to be placed on the nature of physics knowledge.     

数字梳状滤波器

高清晰度的数字电视和模拟电路为主的普通电视,主要区别在于对亮色信号的分离处理上,数字电视亮色分离的关键器件是数字梳状滤波器,本文对数字梳状滤波器特性进行了较为详细的分析.     

广义PC方程的孤立波解

为了进一步研究Pochha mmer-Chree方程孤立波解的特性,考虑了Pochhammer-Chree方程广义形式的孤立波解的存在性．运用双曲函数法和指数函数法求出广义Pochhammer-Chree方程的孤立波解,并给出此方程多个新的显式精确孤立波解,表明广义Pochhammer-Chree方程的孤立波解是存在的,也说明双曲函数法和指数函数法是求方程孤立波解的有效工具．     

Surface-mounted bender elements for measuring horizontal shear wave velocity of soils

The bender element testing features its in-plane directivity, which allows using bender elements to measure the shear wave velocities in a wider range of in-plane configurations besides the standard tip-to-tip alignment. This paper proposed a novel bender element testing technique for measuring the horizontal shear wave velocity of soils, where the bender elements are surface- mounted and the axes of the source and receiver elements are parallel to each other. The preliminary tests performed on model ground of silica sand showed that, by properly determining the travel distance and time of the shear waves, the surface-mounted bender elements can perform as accurately as the conventional ＂tip-to-tip＂ configuration. Potentially, the present system provides a promising nondestructive tool for characterizing geomaterials and site conditions both in laboratory and in the fields.     

侧面波的研究

当球面声波由介质1进入介质2时,如果波速c1相似文献