A digital filtering scheme for SQUID based magnetocardiography

Considering the properties of slow change and quasi-periodicity of magnetocardiography (MCG) signal, we use an integrated technique of adaptive and low-pass filtering in dealing with two-channel MCG data measured by high $T_{\rm c}$ SQUIDs. The adaptive filter in the time domain is based on a noise feedback normalized least-mean-square (NLMS) algorithm, and the low-pass filter with a cutoff at 100Hz in the frequency domain characterized by Gaussian functions is combined with a notch at the power line frequency. In this way, both relevant and irrelevant noises in original MCG data are largely eliminated. The method may also be useful for other slowly varying quasi-periodical signals.     

Mathematical concepts and their physical foundation in the nonstandard analysis theory of turbulence

Main mathematical concepts and their physical foundation in the nonstandard analysis theory of turbulence are presented and discussed. The underlying fact is that there does not exist the absolute zero fluid-volume. Therefore, the physical object corresponding to the absolute point is just the uniform fluid-particle. The fluid-particle, in general, corresponds to the monad. The uniform fluid-particle corresponds to the uniform monad, while the nonuniform fluid-particle to the nonuniform monad. There are two kinds of the differentiations, one is based on the absolute point, and the other based on the monad. The former is adopted in the Navier--Stokes equations, and the latter in the fundamental equations presented in this paper for the nonstandard analysis theory of turbulence. The continuity of fluid is elucidated by virtue of the concepts of the fluid-particle and fluid-particle at a lower level. Furthermore, the characters of the continuity in two cases, i.e. in the standard and nonstandard analyses, are presented in this paper. And the difference in discretization between the Navier--Stokes equations and the fundamental equations given herein is also pointed out.     

Singular value decomposition with normalized period for magnetocaridiography signal processing

In this paper, we have developed an algorithm based on singular value decomposition (SVD) for matrix. And the novel SVD algorithm with normalized period of cardiac cycles is presented. The results from real magnetocardiography (MCG) data processing show that the new algorithm is better than the standard one not only in suppressing noises, but also in providing high-fidelity MCG signals.     

铁(Ⅲ)-柠檬酸盐配合物光解引发橙黄Ⅱ的脱色

光降解;铁(Ⅲ)-柠檬酸盐配合物光解引发橙黄Ⅱ的脱色     

结晶聚合物的辐射效应 Ⅰ.γ-辐照尼龙1010的聚集态结构

本文通过WAXD和DSC等方法研究了γ-辐照尼龙1010聚集态结构的变化,结晶损伤和无定形化的过程。这些过程和结晶与非晶界面原子参与化学反应密切相关,结晶损伤从结晶表面开始,随着辐照剂量增加逐渐向结晶内伸展,直到完全无定形化。     

悬链式单点系泊浮筒主尺度可行域研究北大核心CSCD

为了能够设计合理的单点浮筒主尺度,归纳提出了悬链式单点浮筒5条主要设计原则.基于实际工程经验给出了浮筒重量的母型预估方法,探讨储备浮力,提出等干舷方案集,基于静力学原理和水动力分析探讨了浮筒的自由漂浮稳性及浮筒的运动响应,梳理了垂荡及摇摆随浮筒直径的变化规律.以25 m和100 m水深的浮筒直径上限和下限为边界建立可行域,分别以三个实际项目采纳的浮筒直径和45 m水深下单点浮筒直径的可行范围为参考,开展浮筒直径可行域的验证.研究表明:环境条件等不同因素也会引起相同水深下浮筒直径可行域的变化,因此在可行域的实际应用中应进一步考虑一定的偏差裕量.该文的可行域研究对于悬链式单点浮筒的主尺度确定具有积极的指导意义.     

CHARACTERIZATION OF γ-IRRADIATED CRYSTALLINE POLYMERS Ⅱ ISOTHERMAL CRYSTALLIZATION KINETICS OF γ-RADIATION INDUCED CROSSLINKED POLYAMIDE 1010

Polyamide 1010 is a γ-radiation crosslinkable polymer. After irradiation, it is possible to raise its service temperature up to 240℃. Network formation greatly changes the crystallization behaviour of the polymer. In the present work, DSC was used to examine its isothermal crystallization kinetics. It is found that in addition to the necessity of more undercooling and the lowering of crystallization rate, the primary crystallization stage of the irradiated polymer is shortened. This effect is more evident with increasing radiation dose and content of enhanced difunctionai erosslinking agent. However, the crystallization mechanism of the primary stage is not changed as evidenced by the constancy of Avrami exponent. The lamella end surface free energy σ_e calculated according to Hoffman's equation is very sensitive to γ-radiation. It increases abruptly in 2—3 fold even though the radiation dose is not high enough. The origin of this phenomenon may be accounted for in terms of network structure of the polymer.     

聚酰胺—1010的辐射裂解与后裂解机理的ESR研究

用电子顺磁共振技术（ＥＳＲ）研究了ｒ－辐射聚酰胺－１０１０中俘获自由基的结构、升温中的转化与行为，及它们与其结构和转变多得性的联系，讨论了聚酰胺－１０１０辐射解和后裂解的反应机理及反应区域等问题。     

结晶聚合物的辐照效应——Ⅰ.尼龙-1010的聚集态结构对其辐射化学反应的影响

本文用DSC,WAXD,ESR和介电谱以及凝胶分数测定等技术,研究Nylon-1010的聚集态对γ-辐射化学反应以及辐照后热处理结果的影响。结果表明,辐照Nylon-1010的交联与裂解反应主要发生在非晶区或结晶表面,进一步证明了非晶区也是辐射后交联和后裂解主要反应区。     

聚酰胺1010的60Coγ-射线辐照后效应

用ESR测定了在室温下⁶⁰COγ-射线辐照的聚酰胺1010和添加N,N'-双马来酰亚胺-4,4’-二苯基甲烷的聚酰胺1010的自由基,以及在升温和高温恒温过程中自由基的衰减。热处理引起俘陷自由基消亡,导致聚酰胺1010凝胶含量增加,起补充交联作用。