基于分形理论的麻醉监测诱发脑电信号识别方法研究

提出了一种基于分形理论的麻醉监测诱发脑电信号识别方法.首先给出了麻醉监测中潜伏期听觉诱发脑电信号的数学模型,产生与实际信号相符的模拟脑电信号,然后对脑电信号进行小波降噪,提取降噪后脑电信号的关联维数,最后通过关联维数的大小识别麻醉状态下中潜伏期听觉诱发脑电信号的类型.实验仿真结果表明:提出的识别方法具有较高的识别率.     

一种改进的WLAN-3G融合网络认证协议

本文在分析了现有3GPP WLAN-3G融合网络接入认证协议EAP-AKA的优势和不足的基础上,引入WAPI证书鉴别机制,提出WAPI-3G互联结构模型,并针对该互联模型设计了一种接入认证协议EAP-WAPI.本文提议的WLAN-3G互联结构模型及接入认证机制解决了融合组网环境下WLAN终端统一接入认证的问题.分析和仿真结果表明,相比于原有的WAPI认证协议WAPI-XG1,本文所提议的协议具有较高的安全性和执行效率.     

DFT Study on the Correlation between Thermodynamical Property and Molecular Structure of Polybromo-phenoxathiin

Complete optimization was conducted for 136 polybromo-phenoxathiin congeners(PBPTs) on the B3LYP/6-31G* level with Gaussian 03 program.The structural parameters and thermodynamical parameters of each molecule were obtained under the standard state of 298.15 K and 1.013×105 Pa.Reverse linear regression was employed to establish the quantitative structure-property correlation models between heat capacity at constant volume(CVθ),entropy(Sθ),standard heat of formation(△fHθ) and standard free energy of formation(△fGθ) of PBPTs and the structural parameters(the most negative atomic charge(q-) and molecular average polarizability(α)).These models presented better correlations(r20.97).And they were validated by variance inflation factor(VIF) and t-test,which can better explain the regularity of thermodynamical property of PBPTs,and has good stability and great prediction ability.     

壳聚糖维生素C复合物的合成及性能

通过离子间静电引力作用合成了壳聚糖维生素C复合物。采用红外光谱和差热分析测试技术表征了复合物的结构。溶解度测定结果表明,该复合物具有水溶性。邻苯三酚自氧化速率测定结果表明,该复合物对.O2-的清除作用优于壳聚糖。     

电感耦合等离子体-质谱法测定高纯ZnS粉末中痕量金属杂质

建立了用电感耦合等离子体-质谱(ICP-MS)法测定高纯ZnS粉末中Mg、Al、Mn、Ni等11种痕量金属杂质含量的方法。样品溶解后可直接进样分析。加标回收率为89%~120%。各金属杂质均为10 ng/mL的混合标准溶液平行7次进样的相对标准偏差均小于5%。方法能够满足纯度在99.99%~99.999%范围的ZnS样品中杂质测定的需要。     

数字微镜近红外光谱仪光学系统设计与实验

针对传统光谱仪体积大、成本高、检测速度慢、需样品前处理等不足,提出了利用数字微镜面阵(DMD)实现光谱谱面分割分时选通的近红外光谱仪光学系统.首先,对比传统光路介绍单探测器微型光谱仪系统测量原理;然后结合DMD特性提出光路方案,根据几何光学原理进行初步光学元件选型和光路结构设计,利用ZEMAX光学软件对光路进行仿真,确...     

关于超音速多普勒效应的思考

超音速多普勒效应由于其不便于测量,基本停留在纯理论分析阶段,导致人们产生了一些错误的观点.本文通过逻辑分析、计算机软件模拟等手段,对超音速多普勒效应的音频时序进行了分析研究,找出了错误观点产生的原因,作出了相应的解释,并对错误观点进行了修正,提供了解决方案.     

Study of radiation background at the north crossing point of the BEPCⅡ in collision mode

Understanding the radiation background at the north crossing point (NCP) in the tunnel of BEPCII is crucial for the performance safety of the High Purity Germanium (HPGe) detector, and in turn of great significance for long-term stable running of the energy measurement system. Therefore, as the first step, a NaI(Tl) detector is constructed to continuously measure the radiation level of photons as background for future experiments. Furthermore, gamma and neutron dosimeters are utilized to explore the radiation distribution in the vicinity of the NCP where the HPGe detector will be located. Synthesizing all obtained information, the shielding for neutron irradiation is studied based on model-dependent theoretical analysis.     

GISAXS and SAXS studies on the spatial structures of Co nanowire arrays

The spatial structures of magnetic Co nanowire array embedded in anodic aluminium membranes were investigated by grazing incidence small angle X-ray scattering (GISAXS) and conventional small angle X-ray scattering (SAXS) techniques. Compared with SEM observation, the GISAXS and SAXS measurements can get more overall structural information in a large-area scale. In this study, the two-dimensional GISAXS pattern was well reconstructed by using the IsGISAXS program. The results demonstrate that the hexagonal lattice formed by the Co nanowires is distorted (a ≈ 105 nm, b ≈ 95 nm). These Co nanowires are isolated into many structure domains with different orientations with a size of about 2 μm. The SAXS results have also confirmed that the nanopore structures in the AAM can be retained after depositing Co nanowires although the Co nanowires can not completely but only just fill up the nanopores. These results are helpful for understanding the global structure of the Co nanowire array.