Ionization potential measurements of hydrogenated lithium clusters

Ionization Potentials of Li_nH_m clusters have been measured by photoionization. As in Li_n, odd-even alternations and shell closing effects are observed. In a first approximation, we find that Li_nH clusters behave like Li_n–1 and Li_nH₂ like Li_n–2. The results may be interpreted by assuming that the bonding of one hydrogen localizes one electron and that the other electrons remain delocalized.     

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提出了一种大功率四极管调制器的嵌入式反馈控制系统的设计方法。该系统以DSP为控制核心,采用闭环反馈控制,开发了大功率四极管的高压端控制器,并在系统反馈信号传输中采用一种新的改进型VF光纤隔离传输方案,提高了反馈信号的传输速度。实验结果表明,该嵌入式反馈控制系统简化了HL-2A装置原有的系统,极大地提高了系统响应速度,改善了四极管输出性能,且工作可靠稳定。     

Kinetic of Patent Blue VF Adsorption from Aqueous Solution on Activated Bone Charcoal

The effect of temperature of activation on bone charcoal, used as adsorbent for the removal of Patent Blue VF from water solutions was studied. The adsorbent was characterized by FTIR, XRD, SEM and EDS. The kinetic of adsorption of dye was carried out at 10 °C and 45 °C. Carbonization temperature (600–1000 °C) of the adsorbent has significant effect on the removal of dye from water solutions. The first order kinetic, Elovich, Bangham, parabolic diffusion and power function equations were found to fit the kinetic data. Activation energies of adsorption (Δ≠) have higher values for the charcoal activated at high temperatures and the other thermodynamic parameters like ΔH≠, ΔS≠ and ΔG≠ were also found.     

VT and VF classification using trajectory analysis

Visual classification of Ventricular Fibrillation (VF) and Ventricular Tachycardia (VT) patterns is a hard task for cardiologists. VT and VF signals are apparently similar in the time domain but their underlying information is totally different. In this paper, an image-based technique is presented which extracts discriminative information from the trajectories of VT and VF signals in the state space. In this way, first, signals are sketched in the state space by the delay time method. Then, the state space is considered as an image and trajectories of VT and VF signals are considered as two different images. The purpose is to design some masks, apply them on the images, and finally classify these masked images by a box counting method. These masks are designed to remove the common information between the two patterns and just discriminative pixels are flagged. After applying the masks, flagged pixels are counted and a threshold is determined through the cross validation phase under the receiver operator curve (ROC) criterion to classify the VT and VF trajectory images. The signals are selected from two different data sets include MIT/BIH and CCU of the Royal Infirmary of Edinburgh. Our experiments show brilliant results which provide 100% classification rate on the training and testing phases. Even, through the cross validation phase, the results remained the same also, so thep value is determined as less than 0.0001, that experimentally shows no over-fitting is occurred.     

Study of a plasticized‐unoriented P(VF2/VF3) (73/27 mol%) copolymer. I. The effects of crystallization conditions on morphology,physical, and thermal properties

The results of a study on the effects of a plasticizer, tricresyl phosphate, on the mechanical and thermal properties of unoriented films of poly(vinylidene fluoride–trifluoroethylene) (VF₂/VF₃) copolymer (73/27 mol%) are presented. Films were prepared by both quenching and slow‐cooling from the melt with plasticizer concentrations of 0, 5, and 10% by weight. For the slow‐cooled films, a reduction in crystallinity by 25% was observed for the heavily plasticized films, together with a reduced dynamic mechanical modulus (≈ 58%) and an increased dielectric constant (≈ 200%). For the quenched films, a small increase in crystallinity was observed together with a reduced modulus and an increased dielectric constant. Measurements of the temperature dependence of the modulus and dielectric constant at 10 Hz. were also carried out from −100°C to 100°C. This data showed that for slow‐cooled films the glass transition temperature decreased from −28°C to ‐52°C at the highest doping level. DSC thermal analysis shows a decrease in the Curie transition (≈ 4°C) and melting temperatures (≈ 9°C) for the quenched films, while the slow‐cooled films only showed a decrease in melting temperature (≈ 10°C), while the Curie transition temperature was unaffected. In addition, evidence of a two‐phase system or a nonferroelectric crystal phase is noted by the presence of two Curie transition temperature peaks. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 19–28, 1999     

大功率四极管调制器的嵌入式控制设计

提出了一种大功率四极管调制器的嵌入式反馈控制系统的设计方法。该系统以DSP为控制核心,采用闭环反馈控制,开发了大功率四极管的高压端控制器,并在系统反馈信号传输中采用一种新的改进型VF光纤隔离传输方案,提高了反馈信号的传输速度。实验结果表明,该嵌入式反馈控制系统简化了HL-2A装置原有的系统,极大地提高了系统响应速度,改善了四极管输出性能,且工作可靠稳定。     

基于DSP的数字图像处理系统的设计和调试

提出了一种数字图像处理系统的设计方案,并阐述了基于TMS320C5402的数字图像处理系统的硬件设计和实现。以SST39VF400A型号为例,对FLASH的烧写及程序加载的方法进行了介绍。     

一种在无机晶体结构中检索特定子结构的计算机方法

提出了一种针对无机晶体化合物的子结构检索方法.该方法以VF2子图同构算法为基础,针对无机晶体化合物的结构特点,采用了两种策略以提高子结构检索的效率:(1)引入晶体的对称性信息避免了在等价原子间进行的大量重复性计算;(2)采用结构编码预筛选可以有效地减少目标结构的数量.我们以在无机微孔分子筛数据库中进行子结构检索为例测试该方法的有效性.测试结果表明,该方法可以快速且准确地在分子筛数据库中检索包含特定子结构的记录.两种检索策略的引入大大降低了子结构检索的复杂度,检索速度可提高3-5个数量级.该方法通过Perl语言实现,具有较好的可移植性.