几乎一切Mersenne数与Fermat数都是素数

在本文中,我们用模型论方法证明:几乎一切Mersenne数与Fermat数都是素数.     

牙轮钻机动态轴压扭矩数据处理

本文对YZ-55型牙轮钻机的动态轴压和扭矩实测数据进行了处理。在数据测取中,采用了遥测技术。在数据的采集、预处理及检验中,利用微机实现了计算程序化。通过对数据的时域和频域分析,揭示了轴压和扭矩数据的特性,为研究牙轮钻机的振动和动态载荷谱提供了依据。     

寒冷地区碾压混凝土坝喷涂聚氨酯施工仿真

碾压混凝土坝表面防护是防止表面裂缝的重要措施.通过现场试验和计算分析,为工程提出合理的保温保湿方案提供了依据,进而研究了喷涂聚氨酯的碾压混凝土坝的施工仿真,并和实测结果进行了对比.研究表明:在大坝表面喷涂聚氨酯泡沫材料具有良好的保温保湿效果,施工仿真分析和实测结果吻合良好.     

蒙特卡洛方法在高能核物理研究中的一些应用

文章分析了蒙特卡洛方法的基本思想和高能核物理中理想气体模型的特点,并利用蒙特卡洛方法研究了高能核物理中理想气体模型中粒子的一些物理量的分布规律.     

微型计算机交互式绘图软件的设计及其功能

本文介绍了一套适用于APPLE-Ⅱ微型计算机的会话式绘图软件(简称CDS)及其功能和特点。绘图过程全部采用人机会话方式。可用于曲线拟合、图案设计、教学演示以及绘制机械图、地形图和其他工程图样。从打印机上可直接输出图形。不熟悉计算机绘图和算法语言的人员使用也十分方便。     

法珀干涉仪干涉级小数部分的误差计算

本文给出了法珀干涉仪中央条纹干涉级小数部分的误差计算。计算结果表明,从亮环图中第一个亮环和第七至第十个亮环的一个的直径求中央干涉级小数部分的误差较小。     

国产电子分色机横向倍率缩放系统

本文对彩色制版的关键设备——国产电子分色机作了简单介绍。提出了电子分色机的横向倍率缩放功能系统的实现方法及其设计方案,在设计方案中采用了锁相环及PWM脉宽调制器以及其他集成电路。     

Biodistribution of fullerene derivative C60(OH)x(O)y

The biological behavior of fullerene derivatives shows their considerable potential application in medicine field. To understand the biodistribution of C₆₀ derivatives as drugs or drug carriers, a simple water-soluble derivative C₆₀(OH)_x(O)_y was labeled with^99mTc. A γ-counter and a single photo emission computed tomography (SPECT) were used to assess the biodistribution and metabolism of the labeled compound in mice and rabbits, respectively. The results showed that the compound could be absorbed rapidly by tissues, especially by coronal bone, breastbone, backbone, extremity honeycomb, liver and spleen. The clearance was slow from all tissues except for brain. The compound might be excreted through urine and enteron. The biodistribution shows some difference from that of Yamago et al. In this note, we discuss the possible reason leading to the difference. Further study is needed to find out to what extent the C₆₀ itself determines the biodistribution of derivatives.     

香兰素合成技术研究进展

综述了以各种原料生产香兰素的合成工艺和萃取分离技术的进展及发展趋势.     

动力学控制合成原子精确的银纳米团簇及催化还原4-硝基苯酚

Synthesizing atomically precise Ag nanoclusters (NCs), which is essential for the general development of NCs, is quite challenging. In this study, we report the synthesis of high-purity atomically precise Ag NCs via a kinetically controlled strategy. The Ag NCs were prepared using a mild reducing agent via a one-pot method. The as-prepared Ag NCs were confirmed to be Ag₄₉(D-pen)₂₄ (D-pen: D-penicillamine) on the basis of their matrix-assisted laser desorption ionization time-of-flight mass spectrometric and thermogravimetric characteristics. The interfacial structures of the Ag NCs were illustrated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The Ag NCs were supported on activated carbon (AC) to form Ag NCs/AC, which displayed excellent activity for the catalytic reduction of 4-nitrophenol with a kinetic reaction rate constant k of 0.21 min?1. Such a high k value indicates that the composite could outperform several previously reported catalysts. Moreover, the catalytic activity of Ag NCs/AC remained nearly constant after six times of recycle, which suggests its excellent stability.