天气雷达塔楼感应雷防护

分析湛江当地的地理环境、气候条件、雷暴规律等,根据雷达系统的雷电防护原则,介绍塔楼防雷分类与等级的确定,新一代天气雷达塔楼的感应雷防护措施,包括接地装置、接地线的设计与施工,雷达机房的屏蔽、电涌保护器的设置等。     

Scanning tunneling microscopy investigations of electropolymerized tetra-arylporphyrin complexes

Scanning tunneling microscopy (STM) studies on poly(Zinc-tetraphenylporphyrin) (poly(ZnTPP)) and poly(Zn- or Pt-tetradimethoxyphenylporphyrins) (poly(Zn8OMeTPP) or poly(Pt8OMeTPP)) deposited through anodic oxidation on platinum surfaces are reported. STM investigations on these metalloporphyrin films were conducted to obtain informations on the supramolecular architecture of these polymers. These STM images indicate that poly(ZnTPP) covered the metallic electrode with a layered structure. For poly(Zn8OMeTPP) and poly(Pt8OMeTPP) a tendency to form regular molecular assemblies is obvious.     

金属结单电子晶体管的模型建立及实验验证

在正统理论的基础上,使用主方程法建立了金属结单电子晶体管的器件模型和算法流程.将电容、电阻和温度等参数代入器件模型得到的I-Ⅴ特性曲线与实验结果吻合较好,从而验证了模型、算法以及程序流程的正确性.此外,通过详细讨论模拟与实验的三组曲线差别,得到模型使用主方程的稳态解是导致模拟与实验之间结果存在差别的主要原因,即求解含有时间的主方程将增加模拟精度;而且,指出镜像电荷引起的电势使电流随电压呈现指数增加的主要影响因素,明显偏离理论模拟的线性增加趋势.     

Fundamentals of MRAM Technology

Developments in portable communication and computing systems are creating a growing demand for nonvolatile random access memory that is dense and fast. None of the existing solid-state memories can provide all the needed attributes in a single memory solution. Therefore, to achieve the required multiple functionality requirements, a number of different memories are being used while compromising performance and adding cost to the system. Magnetoresistive Random Access Memory (MRAM) has the potential to replace these memories in various systems with a single, universal memory solution. Key attributes of MRAM technology are nonvolatility and unlimited read and write endurance. In addition, MRAM can operate at high-speed and is expected to have competitive densities. In this paper we describe several fundamental technical and scientific aspects of MRAM with emphasis on recent accomplishments that enabled our successful demonstration of a 256 kbit memory chip.     

综合录井仪的电磁干扰及其抑制

该文在分析综合录井仪电磁环境的基础上,介绍了构成综合录井仪电磁干扰的基本要素及其抑制方法,系统阐述了SLZ综合录井仪设计生产中抑制干扰的措施。     

Scanning tunnelling microscopy imaging of [3 × 3] Mn nonanuclear grids

The scanning tunnelling microscopy imaging of [3 × 3] Mn(II) nonanuclear grids on gold substrates is described. Self‐assembled behaviour is observed at both high and low coverage, with submolecular resolution of individual molecules displayed at low deposition concentrations. The importance of proper image processing techniques is demonstrated in resolving the layer structure at high coverage.     

金属结单电子晶体管的模型建立及实验验证

在正统理论的基础上，使用主方程法建立了金属结单电子晶体管的器件模型和算法流程．将电容、电阻和温度等参数代入器件模型得到的I-V特性曲线与实验结果吻合较好，从而验证了模型、算法以及程序流程的正确性．此外，通过详细讨论模拟与实验的三组曲线差别，得到模型使用主方程的稳态解是导致模拟与实验之间结果存在差别的主要原因，即求解含有时间的主方程将增加模拟精度；而且，指出镜像电荷引起的电势使电流随电压呈现指数增加的主要影响因素，明显偏离理论模拟的线性增加趋势．     

Specific aspects on crack advance during J-test method for structural materials at cryogenic temperatures

Cryogenic elastic plastic, J‐integral investigations on metallic materials often show negative crack extension values with respect to resistance curve J‐R. According to the present ASTM standard, the use of unloading compliance technique relies on the estimation procedure of the crack lengths during the unloading sequences of the test. The current standard, however, does not give any specific procedure for treating such negative data. To date, the applied procedure uses the shifting of the negative crack extension values either to the onset of the blunting line or to the offset of the resistance curve. The present paper represents a solution of the negative crack length problem on the basis of a mechanical evaluation procedure of the unloading slopes. The achieved progress using this evaluation technique is demonstrated on different materials such as cryogenic high toughness stainless steels, low carbon ferritic steel and aluminum alloys from the series of 7000 and 5000. In addition, this work deals with the crack tunnelling phenomenon, observed for high toughness materials, and shows the reduction of this crack extension appearance by using electro discharge machining (EDM) side groove technique. The differences between EDM processed side grooves and standard V‐notch machining have been investigated within these test series.     

Direct observation of the stacked structure in substituted copper phthalocyanine LB films with STM

The in-plane molecular structures of octa-alkyl substituted copper phthalocyanine LB films deposited on graphite have been resolved with a scanning tunnelling microscope (STM). The face-to-face stacking of Pc macrocycles has been observed in the topographies of R₈PcCu monolayers. The stacking period was found to be 3.8–4 Å and the molecular rows were separated by 19 Å and 16 A for (C₆H₁₃)PcCu and (C₅H₁₁)PcCu respectively.