OFDM技术及其应用

首先对OFDM的发展以及应用做了简要的介绍,然后讨论了当前OFDM研究过程中的两个关键技术问题,最后展望了OFDM的未来发展。     

Fuzzy-Fusion Classifier for MMV Full-Polarization Radar Target Recognition Using One-Dimensional Scattering Centers

One-dimensional (1-D) scattering centers on a target can be used for radar target recognition purpose. In this paper, a new classifier based on fuzzy techniques is proposed, which is very much suitable for target recognition using 1-D scattering centers. Furthermore, information fusion techniques for full polarimetric receiver data are utilized at the decision level. The performance of the proposed fuzzy-fusion classifier is evaluated using a dataset of five aircraft models measured by millimeter-wave (MMW) full-polarization stepped-frequency radar in the compact range facility.     

软土基坑工程中劈裂注浆防渗机理与应用

结合紧邻市政管线的软土基坑工程 ,分析劈裂注浆力学和防渗性能 ,确定技术方案 ,控制施工参数 ,在控制管线位移的前提下达到基坑防渗要求 ,为类似工程提供借鉴     

基于虚拟仪器功率测试分析系统

介绍基于虚拟仪器的功率测试分析系统的构成，软件设计以及数据采集、信号处理和整体结构。该系统已在实际应用中取得很好效果。     

低电阻率气层测井评价方法

粘土矿物成份是造成气层电阻率低的主要原因。用灰色静态模型计算孔隙度，用BP神经网络计算束缚水饱和度等参数。与岩心分析结果比较，储层参数计算结果精度有所提高。用储层参数建立气层和水层的判别式，判别结果与试油有较好的一致性。综合数字处理结果建立了气层产能评价模型，处理结果与试油结果比较，符合率82％。     

叠后地震剖面的线性化波阻抗反演

本文提出了由井旁道出发逐道进行的叠后地震剖面的线性化波阻抗反演方法。每一道反演采用逐次线性化对波阻抗进行修正，反演的纵向分辨率为一个采样时间间隔，并以合成记录道与实际地震道的相似系数作为迭代收敛准则，已处理的地震道波阻抗作为下一道反演初始值。实际资料处理表明，该方法具有较高的分辨率和运算速度快的优点。     

Crosslinking of poly(vinyl chloride) with bismaleic compound. II. Rheological behavior and mechanical properties of crosslinked PVC

In this study the rheological behavior of crosslinking PVC was studied. We carefully probed the effects of styrene and initiators on crosslink course and further verified PVC's crosslink mechanism suggested previously. St as auxiliary crosslinker was very important for PVC crosslink, no matter whether at lower temperature or at higher temperature, in the absence of initiator or in the presence of initiator. With higher decay temperature cumvl hydroperoxide (CHP) was a very appropriate initiator for PVC crosslinking. By controlling technological conditions, the crosslinked PVC with different cross density was obtained. We found that PVC with THF-insoluble fraction of about 7% had the best tenacity and maximum breaking energy. The tensile strength would increase as the gel-fraction content increased. By citing T. Kurauchi's ROF toughening theory, we satisfactorily explained the good ductility of crosslinked PVC with low cross density and the high fragility of over-crosslinked PVC. Because the motion of segments is hindered in thoroughly crosslinked PVC, its glass transition was so weak that we hardly found out T_g.     

Characterization of protease-catalyzed hydrolysis of cyanine-labeled angiotensin using capillary electrophoresis with laser-induced fluorescence detection

The hydrolytic cleavage of a cyanine (Cy3)-labeled angiotensin, catalyzed by various proteases, was studied by capillary electrophoresis (CE) with laser-induced fluorescence detection (LIF). The end-labeled peptides and the Cy3 diacid internal standard were separated on a 20-microns x 27-cm capillary with LIF detection (emission, 580 nm) using a frequency-doubled solid-state diode laser emitting at 532 nm or a He-Ne laser emitting at 543 nm. Hydrolysis of the Cy3-labeled angiotensin I, catalyzed by proteinase K, is a sequential process beginning from the C-terminal of the peptide, instead of from random cleavages. Trypsin catalyzes a specific cleavage of Cy3-angiotensin I to Cy3-Asp-Arg as anticipated. Using a combination of endopeptidase and carboxypeptidases, the remnant of the labeled species was characterized by CE-LIF. The method provides a general tool for studying the mechanism of protease-catalyzed hydrolysis of peptide.     

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本文在肯定聚合物泥浆提高钻井速度的同时,也指出了该种泥浆在井内使用较长时间以后将会出现网架结构强、包被抑制性能减弱的弊病。为此,文中强调推出新的聚合物材料,研究泥浆中聚合物剩余浓度的测定方法及控制浓度的要领,提高固控效率净化泥浆等措施以解决之。