Early-warning signals for an outbreak of the influenza pandemic

Over the course of human history, influenza pandemics have been seen as major disasters, so studies on the influenza virus have become an important issue for many experts and scholars. Comprehensive research has been performed over the years on the biological properties, chemical characteristics, external environmental factors and other aspects of the virus, and some results have been achieved. Based on the chaos game representation walk model, this paper uses the time series analysis method to study the DNA sequences of the influenza virus from 1913 to 2010, and works out the early-warning signals indicator value for the outbreak of an influenza pandemic. The variances in the CGR walk sequences for the pandemic years (or + -1 to 2 years) are significantly higher than those for the adjacent years, while those in the non-pandemic years are usually smaller. In this way we can provide an influenza early-warning mechanism so that people can take precautions and be well prepared prior to a pandemic.     

不同尺寸纳米氧化锌的制备及其抗菌性能研究

溶液化学方法在制备ZnO纳米材料时最为常用,通常情况下,可以采用水或其它有机溶剂作为反应介质,制备不同尺寸和形貌的ZnO纳米粒子。本文以油酸钠为表面活性剂,乙酸锌为前驱体,使用不同醇溶剂(乙醇、正丁醇、正己醇),通过控制反应温度,在较为温和的反应条件下,成功制备了不同尺寸的球形纳米ZnO粒子。使用透射电子显微镜(TEM)和高分辨透射电子显微镜(HRTEM)、X-射线衍射(XRD)和紫外-可见吸收光谱(UV-vis)等方法对所得到的ZnO纳米粒子进行了表征,在此基础上,选取其中五种不同尺寸的ZnO纳米粒子,使用平板浇注法,探究不同尺寸ZnO纳米粒子对大肠杆菌和金黄葡萄杆球菌的抗菌效果。结果表示:随着醇溶剂碳链长度和温度的增加,ZnO纳米粒子的尺寸会逐渐增加;随着ZnO纳米粒子的尺寸的减小,其抗菌效果逐渐增强。相比于金黄葡萄杆球菌,ZnO纳米粒子对大肠杆菌的抗菌效果较差。当ZnO纳米粒子的浓度为6×10^-3mol·L^-1时,对金黄葡萄杆球菌和大肠杆菌的抑菌率分别达到了96.6%和91.4%。     

Chaos game representation walk model for the protein sequences

A new chaos game representation of protein sequences based on the detailed hydrophobic--hydrophilic (HP) model has been proposed by Yu et al (Physica A 337 (2004) 171). A CGR-walk model is proposed based on the new CGR coordinates for the protein sequences from complete genomes in the present paper. The new CGR coordinates based on the detailed HP model are converted into a time series, and a long-memory ARFIMA(p, d, q) model is introduced into the protein sequence analysis. This model is applied to simulating real CGR-walk sequence data of twelve protein sequences. Remarkably long-range correlations are uncovered in the data and the results obtained from these models are reasonably consistent with those available from the ARFIMA(p, d, q) model.     

熔渣颗粒碰壁的相变沉积热过程模拟

离心粒化方法在高温熔渣余热回收方面具有结构紧凑、能耗低、得到的渣粒粒径小等优势。但受到粒化仓空间限制,会出现高温熔融渣粒碰撞、黏附在壁面的现象,影响装置运行的稳定性。本文针对该问题建立了熔融渣粒碰撞壁面的三维对称模型,结合VOF(流体体积)方法和凝固/融化模型来模拟熔渣动态形变和凝固换热过程。模拟得到,两个同粒径熔融渣粒在壁面上相继沉积会出现碰撞、铺展、回缩、飞溅、稳定的动态行为。进一步,讨论了熔渣初始温度和冷却风速对其形变和凝固换热的影响。结果表明,熔渣初始温度越小,铺展因数越小,凝固所需时间延长。而冷却风速(1~3 m/s)对熔渣碰壁过程中的铺展形变和换热的影响都很微小。     

基于离子液体和二芳基乙烯的离子凝胶的光致变色、导电、自修复及柔性传感性能

在丙烯酸聚合中原位引入4,4''-(全氟环戊烯-1,2-二基)双(5-甲基噻吩-2-甲醛)(DEA)和离子液体1-丁基-3-甲基咪唑四氟硼酸盐((BMIm) BF₄),制备了一种同时具有光致变色、导电、自黏附且具有宽温度工作区间等性能的新型离子自修复凝胶DPZI。由于(BMIm) BF₄的高热稳定性和低蒸气压,所获得的DPZI凝胶在-20~40℃较宽的温度下表现出高度稳定的机械和离子导电性能。DPZI系统中引入的Zn²⁺与—COO^-形成动态配位键,使得凝胶具有快速的自修复能力,0.06 s即可超快恢复电阻响应;离子液体的引入同时赋予了凝胶优异的抗冻性。DPZI因光致变色单元DEA的异构化可在10 s内快速发生黄-蓝颜色可逆转变,且光致变色单元的开环/闭环异构化能够实现对凝胶导电性的调节。此外,DPZI凝胶应变/压力式传感器可迅速、精准感知人体不同部位的运动并做出相应的响应;也可对呼吸、心率、声音做出精准识别,应变灵敏度为0.2%。     

弹道输运与高温超导电性

本文在引入了弹道输运的概念后,对高温超导体正常态下电阻率和霍耳效应的各向异性以及它们奇异的温度特性统一地进行了解释;对温差电势率的各向异性及其温度行为进行了讨论;也分析了高温超导体由正常态向超导态转变的过程,并给出了超导转变温度与材料一些物理参数的关系.     

高效液相色谱法同时测定妊娠合并乙型肝炎患者血浆中的吲哚与3-甲基吲哚

建立了一种高效液相色谱-荧光检测法用于同时测定血浆中的吲哚与3-甲基吲哚。样本经液液萃取法提取,采用Shim-Pack VP-ODS柱(150 mm×4.6 mm,4.6μm),以15 mmol/L磷酸二氢钠溶液-甲醇(40∶60,v/v)为流动相,甲奈酚为内标,荧光激发和发射波长分别为274 nm和340 nm。吲哚和3-甲基吲哚的线性范围分别为2.22~88.89μg/L和1.11~44.44μg/L;检出限分别为0.11μg/L(吲哚)和0.06μg/L(3-甲基吲哚);平均回收率为95.5%~112.3%,日内与日间相对标准偏差均小于6.8%。利用该方法对妊娠合并乙肝患者(n=29)和正常孕妇(n=46)的血浆进行了测定,结果表明妊娠合并乙肝患者血浆中吲哚和3-甲基吲哚水平均显著高于正常对照组,且与肝损伤指标转氨酶水平呈正相关。     

集值优化问题强有效解集的连通性

在局部凸拓扑线性空间中给出了集值向量优化问题强有效解的连通性定理.该定理是在可行域为弧连通的条件下得到的.     

具有五对特殊方向的一类平面齐五次系统的全局拓扑结构

研究了一类具有五对特殊方向的平面齐五次系统的全局拓扑分类及系数条件.     

具有六对特殊方向的一类平面齐五次系统的全局拓扑结构

In this paper,a class of plane homogeneous fifth system with six special direction is studied,and the global topological classification and coefficient conditions is discussed.