基于灰色预测和KID离群点检测的AUV故障诊断

提高故障诊断能力对于确保水下机器人AUV系统的稳定运行具有重要意义。针对水下机器人推进器系统,提出一种基于离群点检测的AUV故障检测方法。首先,将传感器采集的数据进行灰色预测处理;然后,提出了一种结合K-mean和DBSCAN的改进迭代聚类(Iterative K-mean DBSCAN,IKD)算法进行离群点检测;最后,与K-mean和DBSCAN算法相比,仿真实验结果表明基于灰色预测和KID离群点检测算法的故障检测准确率高,能够有效地实现水下机器人AUV的无监督故障诊断。     

聚（3，4-二氯）噻吩的制备及表征

以四氯噻吩为原料,采用化学合成法制备了聚（3,4-二氯）噻吩．对影响合成材料结构规整度的溶剂极性进行了初步探讨,并采用元素分析、红外光谱、^13C NMR核磁谱等对目标产物进行了表征．结果表明,当采用极性较低的乙二醇二甲醚作溶剂时,可得到规整度较高的目标产物．     

A possible experimental observable for the determination of neutron skin thickness

The dependence between neutron skin thickness and neutron abrasion cross section （σnabr） for neutron-rich nuclei is investigated within the framework of the statistical abrasion ablation model. Assuming that the density distributions for proton and neutron are of Fermi-type, and adjusting the diffuseness parameter of neutron density distribution in the droplet model, we find out the good linear correlation between the neutron skin thickness and the abrasion cross section σnabr for neutron-rich nuclei. The uncertainty of neutron skin thickness determined from σnabr is very small. It is suggested that σnabr can be used as a new experimental observable to extract the neutron skin thickness for neutronrich nucleus. The scaling behaviours between neutron skin thickness and σnabr, separately, for isotopes of ^26-35Na, ^44-56Ar, ^48-60Ca, ^67-78Ni are also investigated.     

One-Proton Halo Structure in ^23Al

The Glauber theory is used to investigate the reaction cross section of proton-rich nucleus ^23Al. A core plus a proton structure is assumed for ^23Al. HO-type density distribution is used for the core while the density distribution for the valence proton is calculated by solving the eigenvalue problem of Woods-Saxon potential The transparency function in an analytical expression is obtained by adopting multi-Gaussian expansion for the density distribution. Coulomb correction and finite-range interaction are introduced. This modified G1auber model is suitable for halo nuclei. A dominate s-wave is suggested for the last proton in ^23Al from our analysis which is possible in the calculation of relativistic mean-field theory.     

Shanghai laser electron gamma source and its applications

Shanghai Laser Electron Gamma Source, a high intensity beam line of γ-ray, is expected to generate γ-rays up to the maximum energy of 22 MeV by Compton backscattering between a CO₂ laser and electrons in the 3.5 GeV storage ring of the Shanghai Synchrotron Radiation Facility. The luminosity of SLEGS γ-ray beam is estimated to be 7×10⁷ A^－1W^－1s^－1 in a optimized setup. Indirect measurement of cross section of the key nuclear-astrophysics reaction ¹²C(α,γ)¹⁶O and γ-ray-triggered transmutation of long-lived radioactive wastes are discussed based on the estimated SLEGS γ-ray beam properties.     

β-碳苷硝酸酯的合成

以β-碳苷酮为母体化合物,经选择性保护糖环4,6-位羟基及在发烟硝酸-乙酸酐体系中的硝化反应,合成了一系列结构新颖的β-碳苷硝酸酯类化合物,为新药研发及构效关系的研究提供全新的候选化合物。     

同位旋标度规律的动力学和统计衰变效应

通过同位旋相关的量子分子动力学模型和统计级联衰变模型, 计算了两个相似的同位旋不同的反应系统的同位旋标度规律, 计算的结果表明对于轻粒子碎片, 同位旋标度系数α随反应时间的增加有所变大, 而对于重的余核产物, α随反应时间的增加有所减小; 轻粒子碎片的α基本上保持不变化, 中等质量和重的余核, α与产物的大小相关, 产物越重α越大. 统计级联衰变可以稍微增加同位旋标度参数α, 但是不改变α对于轻粒子和重产物的变化规律.