Vibration analysis of waffle floors

Two-way grillage or waffle floors are used extensively in semiconductor factories as they provide high impedance mounts for manufacturing equipment that is extremely vibration sensitive. This paper presents a mathematical model for the analysis of vibration at the center of a bay and the transmission of vibration along a waffle floor. The mathematical model is compared with finite element models and experimental results from several manufacturing buildings, and shows good agreement. Trends are shown for the displacement and resonance frequency of the floor as the thickness of the floor, size of the bays and the stiffness of the columns are varied.     

基于Intranet环境的现代装备采办技术研究

简要介绍了Intranet技术的内容、国外发展现状和前景、它对传统采办工作的影响以及引起的变革，随后对我军应用Intranet技术面临的形势和挑战进行了简要分析。     

用于放射性砹(碘)标记蛋白质的偶联剂SPC的合成及表征

以5-溴烟酸为起始物，通过3步主要反应合成了一种适用于蛋白质放射性砹(碘)标记的偶联剂——5-(三正丁基锡)-3-吡啶甲酸N-琥珀酰亚胺酯(SPC)，并用核磁共振(NMR)、质谱(MS)、高效液相色谱(HPLC)等进行了表征。以该试剂为双功能偶联剂，实现了IgG的^125I标记，标记率达30％以上。标记产物在体外具有较高的稳定性。     

Atomic Afterimages

This article examines the recirculation of Robert Del Tredici's photographs of the Cold War nuclear weapons complex. Originally published in his groundbreaking book, At Work in the Fields of the Bomb (1987), a number of Del Tredici's photographs have been republished in a series of post‐Cold War US Department of Energy reports. The article examines the post‐Cold War circulation of Del Tredici's images in these official government reports and analyzes shifts in their meaning across different historical periods. Ultimately, this paper raises questions about the critical stance of Del Tredici's photographs as they are republished in government reports and examines ways in which the meaning of his photographs responds to both Cold War and post‐Cold War contexts.     

基于AT89S51的可与计算机交互的电子血压计设计

电子血压计使用简单方便,所得数据客观稳定。本文从示波法血压测试原理出发,设计出电子血压计的系统原理框架。然后以AT89S51单片机为核心,采用BP300T型压力传感器和RS232通信电路,并结合合适的单片机内嵌软件,实现可以与计算机交互的电子血压计。特点是可以与PC机通信,血压测量受PC机控制,由PC机对被测人的血压状况进行监测、分析、存储,因此本系统可在体格检查、医疗监护等各个领域获得广泛的应用。     

Selective nanoshaving of self-assembled monolayers of 2-(4-pyridylethyl)triethoxysilane

Single molecular layers of 2-(4-pyridylethyl)triethoxysilane have been deposited on native oxide surfaces of silicon, with the triethoxysilylethyl groups towards the silicon oxide interface and pyridine at the surface. It is possible to “shave” or mechanically break the molecular bonds at the alkoxy-silane (Si-C) bond using scanning atomic force microscope, leaving large swaths of surface area cut to a depth of 0.64 ± 0.06 nm, exposing the silicon of the alkoxy-silane ligand. Mechanical cleavage of the pyridine ligand alone is also possible, but more difficult to control selectively.     

Effects of oxygen pressure on n-ZnO/p-Si heterojunctions fabricated using pulsed laser deposition

ZnO films were prepared on p-Si substrates using pulsed laser deposition (PLD) and n-ZnO/p-Si heterojunctions were fabricated at different oxygen partial pressures. The effects of oxygen pressures on crystallinity and surface morphology of ZnO films and the I-V characteristics of n-ZnO/p-Si heterojunctions were studied. It was found that the films grown in the oxygen pressure range from 10⁻⁵-10⁻² Torr were all c-axis oriented. The surface morphologies were strongly dependent on the oxygen partial pressure. The current-voltage (I-V) characteristics of the heterojunctions could be classified into two categories depending on the oxygen pressure. At low pressure (10⁻⁵-10⁻⁴ Torr), the I-V curves were similar to those of common p-n junctions. As the oxygen pressure increased to 10⁻³ Torr, the I-V curves changed markedly. Based on the I-V characteristics, an energy band diagram of n-ZnO/p-Si was proposed.     

某待建滨海核电厂厂址年均大气扩散因子计算模式与参数的实验研究

本文在某待建滨海核电厂厂趣现场野外实验基础上提出了计算该核电厂年均大气扩散因子的计算模型。此模型既考虑了向岸流与离岸流的差别，又考虑了混合层与热内边界层，混合释放与扩散参数随陆距变化等因素的综合影响。模型中所需要的各类参数，包括在１９９５，１９９６年间在该厂趣野外大气试验中获取的百米气象铁塔４个不同高度上的风，温逐时三维联合频率；湍流测量结合风洞实验获取的离岸流与向岸流的扩散参数。     

旋风器同侧双进口蜗向回转通道内气尘分离状况分析

建立了同侧双进口蜗向回转通道内三个分离区域内分级效率的公式，理论上分析了同侧双进口蜗向回转通道有利于提高旋风器的分离性能。以收集效率为基础，部分实验验证了这一结论。     

Correction of the method of current-voltage characteristics for determination of density of surface states in the system of germanium-rare-earth element fluoride

The results of studies of the interface of Ge with fluorides of Dy, La, and Sm in the metal-insulator-semiconductor structure are reported. The character of the energy spectrum and density of surface states for the interface of Ge with various fluorides of rare-earth elements is determined. For this purpose, the comparative analysis of the results obtained based on two methods, namely, the methods of current-voltage and capacitance-voltage characteristics, was carried out. The analysis showed that the information found from the current-voltage characteristics should be corrected taking into account the results obtained using other measurements, for example, the capacitance-voltage characteristics. This comparison also provided additional data on the properties of the interface; specifically, the thickness of the layer of the tunneling-thin insulator was determined.