激光诱导Al等离子体连续辐射研究

分析了Ａｌ等离子体连续辐射特征。根据连续辐射强度的同时分布,简要讨论了激光诱导等离子了体连续辐射的产生机理。我们认为激光诱导等离子体的连续辐射的主要机制提轫致辐射和复合辐射。在激光脉冲作用到靶上的瞬间,轫致辐射占主导地位,在等离子体演化初期,复合辐射和轫致辐射共同产生等离子体连续辐射,在等离子体演化后期,连续辐射主要是轫致辐射产生的。     

一种用于个人通信移动终端的四单元宽带微带天线阵

本文分析设计了一种宽带微带天线,该天线为四单元微带天线阵。在宽带单单元微带天线的基础上,采用宽带功率分配网络,组成了适用于个人通信移动终端的宽带微带天线阵。并且给出了电压驻波比的测试结果,以及对测试结果的简单分析。     

单透镜成象系统的分数维傅立叶变换分析

在菲涅耳衍射与分数维傅立叶变换关系的理论基础上 ,给出了这一关系的另一表示方式 ,以此理论和透镜的分数维傅立叶变换特性分析了放大率大于 1和小于 1的单透镜成象系统。结果表明 ,作为菲涅耳衍射的分数维傅立叶变换可以与透镜的分数维傅立叶变换组成分数维傅立叶变换群 ,两次分数维傅立叶变换完成了一次成象过程     

细长导体目标的雷达图像特征

本文讨论如高速公路护拦、铁路轨道等细长导体目标的雷达图像特征。从电磁波与地物目标相互作用的角度,说明了它们在雷达图像上显示为强信号或弱信号的原因。     

Plasma-induced charging damage in ultrathin (3-nm) gate oxides

Plasma-induced damage in various 3-nm-thick gate oxides (i.e., pure oxides and N₂O-nitrided oxides) was investigated by subjecting both nMOS and pMOS antenna devices to a photoresist ashing step after metal pad definition. Both charge-to-breakdown and gate leakage current measurements indicated that large leakage current occurs at the wafer center as well as the wafer edge for pMOS devices, while only at the wafer center for nMOS devices. These interesting observations could be explained by the strong polarity dependence of ultra thin oxides in charge-to-breakdown measurements of nMOS devices. In addition, pMOS devices were found to be more susceptible to charging damage, which can be attributed to the intrinsic polarity dependence in tunneling current between nand p-MOSFETs. More importantly, our experimental results demonstrated that stress-induced leakage current (SILC) caused by plasma damage can be significantly suppressed in N₂O-nitrided oxides, compared to pure oxides, especially for pMOS devices. Finally, nitrided oxides were also found to be more robust when subjected to high temperature stressing. Therefore, nitrided oxides appear to be very promising for reducing plasma charging damage in future ULSI technologies employing ultrathin gate oxides     

Improved lightpath (wavelength) routing in large WDM networks

We address the problem of efficient circuit switching in wide area networks. The solution provided is based on finding optimal routes for lightpaths and semilightpaths. A lightpath is a fully optical transmission path, while a semilightpath is a transmission path constructed by chaining several lightpaths together, using wavelength conversion at their junctions. The problem thus is to find an optimal lightpath/semilightpath in the network in terms of the cost of wavelength conversion and the cost of using the wavelengths on links. In this paper, we first present an efficient algorithm for the problem which runs in time O(k²n+km+kn log(kn)), where n and m are the number of nodes and links in the network, and k is the number of wavelengths. We then analyze that the proposed algorithm requires O(d ²nk₀²+mk₀ log n) time for a restricted version of the problem in which the number of available wavelengths for each link is bounded by k₀ and k₀=o(n), where d is the maximum in-degree or out-degree of the network. It is surprising to have found that the time complexity for this case is independent of k. It must be mentioned that our algorithm can be implemented efficiently in the distributed computing environment. The distributed version requires O(kn) time and O(km) messages. Compared with a previous O(k²n+kn²) time algorithm, our algorithm has the following advantages. (1) We take into account the physical topology of the network which makes our algorithm outperform the previous algorithm. In particular, when k is small [e.g., k=O(log n)] and m=O(n), our algorithm runs in time O(n log² n), while the previous algorithm runs in time O(n log n). (2) Since our algorithm has high locality, it can be implemented on the network distributively     

紫外线诱变固体DNA的拉曼光谱研究

报道了用拉曼光谱法测定紫外线诱变脱氧核糖核酸（ＤＮＡ）前后的拉曼散射结果。实验结果表明,经过紫外线诱变以后,Ａ－ＤＮＡ型结构特征谱线８１０ｃｍ＾－１减弱;分别反应脱氧核糖磷酸盐链振动和Ｃ０Ｏ伸缩振动的谱带８８４ｃｍ＾－１和１０１０ｃｍ＾－１、１０６８ｃｍ＾－１都有不同程度的 减弱;属于脱氧核糖在１４６８ｃｍ＾－１处的谱线显著减弱;还有个别咸基谱带出现（在６７０ｃｍ＾－１处的胸腺嘧啶Ｔ）、增强（在     

激光重熔处理工艺对等离子喷涂热障涂层组织的影响

研究了激光不同工艺参数对等离子喷涂ＺｒＯ２热障涂层组织结构的影响,结果表明：随着激光输出功率的增大,重熔组织由单一柱晶结构变为等轴晶＋柱晶双层结构。ＺｒＯ２层最高显微硬度也随之增大,这与等轴晶的存在有关。对两种不同晶体相结构进行ＸＲＤ分析表明：柱晶结构表现出一定的择优取向。     

TFT工艺中的反应性离子刻蚀

对ＴＦＴ器件工艺中的反应性离子刻蚀技术进行了研究,给出了ＴＦＴ器件工艺中常见薄膜刻蚀速率的实验结果,并讨论了掺杂气体（如Ｈ２、Ａｒ等）对刻蚀速率的影响。     

虚拟专用网络技术

对ＶＰＮ的基本概念作简要介绍后,着重分析了ＶＰＮ的三种典型的应用方式,即Ｉｎｔｒａｎｅｔ ＶＰＮ,远程接入ＶＰＮ和Ｅｘｔｒａｎｅｔ ＶＰＮ,并对现有的一些ＶＰＮ技术进行了总结,提出了一个一般的ＶＰＮ体系结构模型。