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通过宇宙线大气簇射模拟软件CORSIKA,对"膝区"宇宙线进行模拟,获得大气簇射次级粒子的种类和空间分布信息,然后重点对比铁核和质子的次级粒子的分布特征,采用单参数法和双参数法对两种原初宇宙线进行鉴别,并引入优质因子对两种方法的鉴别效果进行研究。结果表明,双参数法的区分效果明显优于单参数,单参数法的鉴别能力随求和区域的增大先升高后变差。 相似文献
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The characteristic gamma-ray spectrum of TNT in the soil induced by DT neutrons is measured by the PFTNA demining system. The GEANT4 toolkit is used to simulate the whole experimental procedure. The simulated spectra are compared with the experimental spectra, and they are mainly consistent. The share of the background sources such as neutrons and gamma is obtained and the contribution that the experimental apparatus to the background, such as shielding, detector sleeve and moderator, is analyzed. The effective gamma signal(from soil and TNT) is 29% of the full spectrum signal, and the background signal, more than 68%, this is mainly produced by shielding and the detector sleeve. By gradually optimizing the shielding and the cadmium sheet of the detector sleeve, the share of the effective gamma signal increases to 47%, and the background signal reduces to 18%. 相似文献
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情感分析是指通过提取文本特征对基于文本的情感倾向进行分类,是自然语言处理领域中的一项重要任务。为了提高文本情感分析的性能,该文将分类任务定义为一个比较问题,并提出了基于比较学习(Comparing to Learn, C2L)的分类模型。C2L的目标是通过与已标注的样本进行比较来对句子进行评分,实际上,通过比较方法进行分类比训练一个过于复杂的模型更加有效。在两个常用数据集上的实验结果表明,C2L的性能优于现有的许多模型;通过调整C2L的内部结构,可以在不同的任务和数据集上取得好的表现。 相似文献
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