核科学百年讲座第七讲核科学技术在材料科学中的应用

核科学技术和材料科学的结合产生了一门新兴的交叉学科——核材料(也称核固体)，主要指核技术在材料分析、物质改性和新材料研制合成中的应用．文章介绍核技术在材料科学中的应用历史、现状及其前景，包括基本物理原理．     

贝叶斯公式的几个应用

介绍了贝叶斯公式的一些应用实例及分析,以使在教学中能帮助学生更深入地理解该公式.     

全概率公式及其应用技巧

对全概率公式的内涵进行剖析、引申与扩展,构造性地运用全概率公式计算一些复杂事件的概率,通过实例探讨其应用技巧.     

时间序列预测模型研究综述

介绍了时间序列预测模型的产生和发展,呈现了时间序列模型研究方向的理论、方法和应用,并就未来的发展势态进行了初步的探讨.     

Matlab软件在高等数学教学中的应用

Matlab是当今最优秀的科技应用软件之一。基于Matlab在科学计算中的强大功能,本文探讨了Matlab软件在高等数学教学中的应用。针对高等数学中的极限、导数、积分、极值等问题,在教学中融入Matlab辅助计算,把所学理论转化为实践,不仅大大地提高了教学的实效性,并且为学生今后运用所学知识解决专业、实际等问题奠定了基础。     

Fiber Optical Bragg Grating Refractometer

We have demonstrated an evanescent field refractive indexfiber sensor comprising a 42-mm Bragg grating in an etched fiber together with a tunable Distributed Bragg Reflector (DBR) laser. Characterization of different aqueous sucrose solutions resulted in a resolution of roughly 10 mM sucrose. The sensor in the presented form has a theoretical sensitivity of higher than 10 5 refractive index unit (riu) in a refractive index region close to the cladding index of the fiber. However, the technique allows for an even higher sensitivity than 10 6 riu with a proper signal processing scheme.     

13C-Leucin-Atemtest zur Beurteilung der anabolen Verwertung von diätetischen Aminosäurengemischen bei Phenylketonurie

It is essential to establish whether and how environmental factors affect the reliability of [¹³C]methacetin breath test (¹³C-MBT). In 12 healthy volunteers (smokers), a standard ¹³C-MBT with 75 mg [¹³C]methacetin was performed twice in random order: on a control day without smoking and on another day with smoking two cigarettes antecedently. A considerable flattening of the curve of the momentary ¹³C recovery within the expiratory air was observed when the ¹³C-MBT was performed after smoking. The maximum of the momentary ¹³C recovery, D _max, decreased from 37.20±2.58 to 25.39±2.29% dose/h (p=0.00052). Moreover, the time to reach D _max was prolonged after cigarette smoking (26.5±3.1 vs. 16.5±1.9 min, p=0.0199). The curve of the cumulative ¹³C recovery on the cigarette smoking day appeared to be shifted downwards, and statistically significant differences relative to the control situation were found between the 24th and 75th minute following [¹³C]methacetin administration. Smoking cigarettes immediately prior to the ¹³C-MBT diminishes the ability of the liver to handle methacetin, and hence a possibility of such an interaction should be excluded in order to interpret the results of the test correctly.     

Improved dynamic MRI reconstruction by exploiting sparsity and rank-deficiency

In this paper we address the problem of dynamic MRI reconstruction from partially sampled K-space data. Our work is motivated by previous studies in this area that proposed exploiting the spatiotemporal correlation of the dynamic MRI sequence by posing the reconstruction problem as a least squares minimization regularized by sparsity and low-rank penalties. Ideally the sparsity and low-rank penalties should be represented by the l₀-norm and the rank of a matrix; however both are NP hard penalties. The previous studies used the convex l₁-norm as a surrogate for the l₀-norm and the non-convex Schatten-q norm (0 < q ≤ 1) as a surrogate for the rank of matrix. Following past research in sparse recovery, we know that non-convex l_p-norm (0 < p ≤ 1) is a better substitute for the NP hard l₀-norm than the convex l₁-norm. Motivated by these studies, we propose improvements over the previous studies by replacing the l₁-norm sparsity penalty by the l_p-norm. Thus, we reconstruct the dynamic MRI sequence by solving a least squares minimization problem regularized by l_p-norm as the sparsity penalty and Schatten-q norm as the low-rank penalty. There are no efficient algorithms to solve the said problems. In this paper, we derive efficient algorithms to solve them. The experiments have been carried out on Dynamic Contrast Enhanced (DCE) MRI datasets. Both quantitative and qualitative analysis indicates the superiority of our proposed improvement over the existing methods.     

非链式HF/DF激光器的研究进展

HF/DF激光器是中红外波段能提供最高能量输出的激光光源,也是中红外波段应用非常广泛的相干光源。本文介绍了近几年国内外关于非链式HF/DF激光器的研究进展及其成果应用,分析了非链式HF/DF激光器在应用方面的优缺点,总结了实现非链式HF/DF激光输出的关键技术和存在的问题,指出了该技术的未来发展方向。     

由历史看数学的应用研究

本文从历史的角度 ,研究了数学应用的情况 .