基于多传感器融合的摔倒检测算法的研究

针对传统摔倒检测算法中误报和漏报率高的不足,提出一种基于多传感器融合的摔倒检测算法。该算法分别以人体的加速度和姿态角值为判定依据。首先,采用三轴加速度传感器和电子罗盘对上述两种数据进行采集,并通过无线模块发送至PC机。之后对采集数据进行分析和处理,进而根据阈值进行异常姿态检测。最终,综合加速度和姿态角的分析结果给出准确的检测结论。实验结果表明,该算法检测的准确率达99.2%、与传统检测算法相比具有更强的稳定性与可靠性。     

火焰原子吸收光谱法测定金属锂中钠

锂作为21世纪的能源金属,在近年得到迅猛发展。它以其特有的核性质成为一种极具发展潜力的稀有元素,由于锂无裂变产物,不会造成辐射污染,已成为发展尖端技术的重要材料。但由于锂中钠、硅、钙等杂质元素的存在,影响了锂的物理化学性质。所以测定金属锂中钠的含量对保证产品的质量至关重要。锂的化合物中微量元素的测定多采用原     

A digital transmission system for high intensity pulsed radial detection

A digital transmission system with 900 MHz bandwidth and over 40 dB linear dynamic range for high intensity pulsed radial detection is designed. The transient signals (with a subnanoseconds rising edge) from the detectors can be transmitted to diagnosing systems kilometers away with high fidelity. It can adapt to interference and a hostile detecting environment by using the intelligent functions of this system. The feasibility and reliability of this system is verified by system evaluation tests.     

小展弦比调节级三维多目标气动优化设计

大功率汽轮机调节级动叶是典型小展弦比叶片。动叶通道内上下通道涡交汇,流动呈现强烈的三维特性,其设计优化本质上是一个三维优化问题。结合自适应多目标差分进化算法、基于能量法的三维叶片造型方法和RANS方程求解技术,发展了轴流式叶栅三维多目标气动优化设计方法。利用该方法,完成了某典型大功率汽轮机调节级多目标气动优化设计。优化后小展弦比调节级气动性能明显提高,表明该方法具有良好的优化性能和应用前景。     

Operation Mechanism of Double-Walled Carbon Nanotubes Transistors Investigated By ab initio Calculations

Recently, a new switching characteristic of double-walled carbon nanotubes （DWNTs） transistors is found in during experiments. We carry out a series of ab intio calculations on DWNTs＇ electronic properities, together with verification on the electronic response under the electric field. Our results reveal that the peculiar energy states relation in DWNTs and related contact modes should account for the distinct switching behavior of DWNT transistors. We believe these results have important implications in the fabrication and understanding of electronic devices with DWNTs.     

CVD人造金刚石核辐射探测器研究进展

金刚石探测器具有体积小、抗辐照能力强、时间响应快等优点,在核辐射领域应用优势显著。早期金刚石核辐射探测器均采用天然金刚石材料,化学气相沉积(chemical vapor deposition, CVD)金刚石人工合成技术的进步,极大地促进了金刚石核辐射探测器的发展与应用。本文从CVD人造金刚石材料入手,分析了制约金刚石探测器性能的杂质与缺陷、CVD金刚石的合成工艺、探测器级金刚石中杂质与缺陷的表征方法,并基于载流子迁移率与寿命乘积、探测器的电荷收集效率等性能指标,总结了CVD金刚石中的杂质与缺陷对探测器性能的影响规律,介绍了国外金刚石核辐射探测器的应用现状并展望了国内金刚石核辐射探测器的发展前景。     

重子相互作用和双重子

本文提出了一个新的夸克势模型──夸克脱定域色屏蔽模型．此模型不用介子交换就给出既有排斥心又有中程吸引的核力,并且定性符合Ｎ－Ｎ散射相移１Ｓ０、３Ｓ１、１Ｐ１和３Ｐ１ａ首次从动力学证明了可能存在两类双重子．一类是像氘核那样的低自旋、弱束缚的双重子,另一类是高自旅、强束缚的六夸克态,ｄ就是一个典型例子,它很可能是一个窄双重子共振态．一个平行的相对论性夸克势模型证实了与上述非相对论势模型有关的双重子态的预言． A new quark potential model, called quark delocalization and color screening model, has been proposed.This model yields both N-N repulsive core and intermediate range attraction without involving the meson exchange and fits the N-N 1S0,3S1,1p1and 3Pls phase shifts qualitatively. It verified dynamically that there might be two kinds of dibaryons.One is the deuteron like low spin, loosely binding two baryon states.The other is the high spin, strong binding six quark states, d. is a typical example and is...