A new hyperchaos system and its circuit simulation by EWB

This paper reports a new hyperchaotic system evolved from the three-dimensional Lü chaotic system. The Lyapunov exponents spectrum and the bifurcation diagram of this new hyperchaotic system are obtained. Hyperchaotic attractor, periodic orbit and chaotic attractor are obtained by computer simulation. A circuit is designed to realize this new hyperchaotic system by electronic workbench.     

细丝直径测量的设计性实验

设计性实验是高校实验教学的重要内容,其中最关键的环节是实验方案的设计。本文列举了细丝直径测量设计性实验的几种测量方案。     

Temperature-dependent photoluminescence of size-tunable ZnAgInSe quaternary quantum dots

Colloidal ZnAgInSe (ZAISe) quantum dots (QDs) with different particle sizes were obtained by accommodating the reaction time. In the previous research, photoluminescence (PL) of ZAISe QDs only could be tuned by changing the composition. In this work the size-tunable photoluminescence was observed successfully. The red shift in the photoluminescence spectra was caused by the quantum confinement effect. The time-resolved photoluminescence indicated that the luminescence mechanisms of the ZAISe QDs were contributed by three recombination processes. Furthermore, the temperature-dependent PL spectra were investigated. We verified the regular change of temperature-dependent PL intensity, peak energy, and the emission linewidth of broadening for ZAISe QDs. According to these fitting data, the activation energy (ΔE) of ZAISe QDs with different nanocrystal sizes was obtained and the stability of luminescence was discussed.     

近红外光谱结合一类支持向量机算法检测鸡蛋的新鲜度

研究利用近红外光谱技术结合模式识别方法识别鸡蛋的新鲜度,在识别模型建立过程中,引入一类支持向量机(OC-SVM)算法解决新鲜蛋和非新鲜蛋训练样本数量不平衡问题。首先获取鸡蛋在10 000～4 000 cm-1范围内的近红外漫反射光谱,通过主成分分析方法提取光谱数据中的特征信息,优选了3个主成分作为模型的输入向量,然后采用OC-SVM区分新鲜蛋和非新鲜蛋。在模型建立过程中,对相关参数进行了优化,试验结果显示在相同条件下,OC-SVM模型识别结果较传统的支持向量机模型好。最优OC-SVM模型对新鲜蛋和非新鲜蛋的识别率均为80%,传统的支持向量机对新鲜度的识别率为100%,对非新鲜度的识别率却为0%。研究结果表明利用近红外光谱快速识别鸡蛋新鲜度方法是可行的;OC-SVM算法为训练样本数量不平衡提供了一种有效的解决方法。     

A specific state variable for a class of 3D continuous fractional-order chaotic systems

A specific state variable in a class of 3D continuous fractional-order chaotic systems is presented.All state variables of fractional-order chaotic systems of this class can be obtained via a specific state variable and its (q-order and 2q-order) time derivatives.This idea is demonstrated by using several well-known fractional-order chaotic systems.Finally,a synchronization scheme is investigated for this fractional-order chaotic system via a specific state variable and its (q-order and 2q-order) time derivatives.Some examples are used to illustrate the effectiveness of the proposed synchronization method.     

Cross-Correlation of Excitation Functions for Different Fragments and Different Scattering Angles in ^27Al（^19F,x）y Reactions

Excitation functions have been measured for different projectile-like fragments produced in ^27Al（^19F, x ）y reactions at incident energies from 110. 25 to 118. 75 Me V in 250 ke V steps. Strong cross section fluctuations of the excitation functions are observed. The cross-correlation coefficients of the excitation functions for different atomic number Z and for different scattering angle θcm have been deduced. These coefficients are much larger than the statistical theoretical calculated ones. This indicates that there are strong correlations between different exit channels in the dissipative heavy ion collision of ^27Al（^19F, x）y.     

用改进的屏蔽氢离子模型计算离子的能量

:用改进的屏蔽氢离子模型[1]计算了离子的电离势和次壳层能量。大量计算数据表明,改进模型计算的结果在低Z低离化时与实验相符;在高Z高离化时与MCDF的结果相符,从而弥补了R.M.More屏蔽氢离子模型、Slater单电子模型、WBEPM模型的不足。     

改进的屏蔽氢离子模型中量子修正Δ_nl的推算

此文用等电子系列实验抛物线关系推算出了改进的屏蔽氢离子模型中量子修正Δnl的值,从而提高了屏蔽氢离子模型计算离子能量的精度     

天然生物材料壳聚糖支架上人胚肺成纤维细胞的生长

采用不同粒度的硅胶粒子作为致孔剂,按硅胶和壳聚糖重量比9：1,制备了三组不同孔径的壳聚糖多孔支架．以无孔壳聚糖支架为参照,对多孔支架的有效孔径、吸水性进行了比较．结果表明：孔径大小由硅胶尺寸控制,吸水性随孔径增大而增大．为研究支架孔径大小对其生物相容性的影响,在系列支架上进行了人胚肺成纤维细胞的培养．细胞种植1d后,多孔支架上的细胞粘附较多,而无孔支架上的细胞伸展情况较好;细胞培养5d后,所有支架上细胞伸展情况良好,孔径越大的支架上细胞增殖越多．该研究结果将为天然生物材料壳聚糖作为组织工程支架材料的应用提供有益的指导．     

针头式滤器水溶出物对样品分析的影响

滤膜材质分别为混合纤维素酯、尼龙、聚四氟乙烯、聚偏氟乙烯、聚醚砜的针头式滤器经去离子水过滤后有溶出物,对样品中F-、Cl-、SO2-4、Br-或NO-3等阴离子的分析可产生显著影响,另有组分可干扰样品的脉冲安培检测。采用电喷雾质谱或气相色谱-质谱能检出混合纤维素酯针头式滤器溶出物中的添加剂成分。对不同品牌及滤膜材质针头式滤器水溶出物的定量分析结果表明,F-、Cl-、SO2-4浓度多在10μg/L以上。针头式滤器对所滤样品的影响不容小觑,亟需相关标准来规范针头式滤器的质量。