排序方式: 共有73条查询结果,搜索用时 15 毫秒
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吉家洼金矿床位于豫西熊耳山上宫金矿集区的西部。通过对矿床地质、主要矿脉地质特征研究,对F1、F2和WF1矿脉进行了矿体趋势预测和找矿前景分析。分析结果表明,WF1矿脉北中部125~119线间、中部123~107线间及南部100~114线间,深部具有较大的找矿潜力;F1、F2矿脉11~8线为找矿有利地段,具有进一步找矿空间。 相似文献
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G.A.B. GálI. Rajta S.Z. SzilasiZ. Juhász S. BiriC. Cserháti A. CsikB. Sulik 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(20):2322-2325
Polycarbonate membranes containing statistically scattered heavy ion track nanocapillaries have been studied by scanning transmission ion microscopy (STIM) method. The geometry of the samples was characterized by pore diameters of about 172 nm and by 30 μm membrane thickness. The porosity has to be relatively low in order to avoid too many overlapping capillaries. The transparency of the sample is reduced by changing its tilt angle to the beam. While the acceptance angle for transmission of a single capillary is below 0.3°, the STIM results have showed that the angular spread was about 1° full width at half maximum (FWHM). This indicates that the capillaries are not perfectly parallel, i.e. the capillary directions have a finite angular spread.Our results are important for the recent use of these types of insulator membranes in ion guiding studies, and the related potential applications. 相似文献
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HAN Xiu-you Photonics Research Center School of Physics & Optoelectronic Engineering Dalian University of Technology Dalian CHN PANG Fu-fei FANG Zu-jie ZHAO Ming-shan 《半导体光子学与技术》2008,14(3):158-161
Based on the measurement of the contrast ratios of the transmission spectra from the throughput and drop ports of ring resonator, an efficient method is proposed to extract the coupling ratio and round-trip loss of the integrated optical waveguide ring resonator. The parameters of a racetrack resonator prepared by ion-exchange technique in K9 optical glass substrate are examined, which demonstrates the validity of this method. The accuracy and applicable range of this method are also discussed. 相似文献
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多重测量矢量模型下的稀疏步进频率SAR成像算法 总被引:2,自引:0,他引:2
基于压缩感知(Compressed Sensing, CS)的合成孔径雷达(SAR)成像算法可以用低于Nyquist采样率的采样数据完成稀疏目标高分辨成像。然而已有的算法在重构1维距离像时采用的大都是单重测量矢量(Single Measurement Vectors, SMV)模型,存在着重构耗时长、受噪声干扰大的缺点。该文从压缩感知的多重测量矢量(Multiple Measurement Vectors, MMV)模型出发,利用多重测量矢量恢复具有相同稀疏结构的联合稀疏目标信号源,从理论与实验角度分析了基于MMV模型的SAR 1维距离像成像性能,提出了一种距离向基于MMV模型,方位向基于SMV模型的2维SAR成像算法。该算法从耗时上、重构精度上均优于SMV模型下的CS成像算法。通过对仿真数据和地基雷达实测数据的处理,验证了算法的有效性。 相似文献
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细间距QFP的焊接技术发展到今天,遇到了一些新问题,如当无铅QFP和有铅焊料混装时,如何解决兼容性的问题,如何去除细间距QFP引脚上的氧化层,如何用激光焊接解决细间距QFP焊接的短路问题,如何用激光清洗的方法去除细间距QFP引脚之间的白色残留物,以及如何对印制板组件进行边界扫描测试等。详细介绍了解决这些问题的新工艺、新方法。实践证明,这些方法都是非常有效和切实可行的。 相似文献
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NX软件采用复合(混合)建模技术,本文以“敏于行”为宗旨,运用建模实战领会NX复合建模;本文提出了几种建模方法,分享了NX复合建模的乐趣。 相似文献