铁氰化钾-钙黄绿素体系流动注射化学发光法测定孔雀石绿

基于在碱性条件下,孔雀石绿可以增强铁氰化钾-钙黄绿素的化学发光,且其浓度在一定范围内与化学发光强度呈线性关系,结合流动注射技术,建立了化学发光法测定孔雀石绿的新方法。在优化的实验条件下,方法的线性范围为3.0×10-8～1.0×10-6 g/mL,检出限为2.5×10-9 g/mL,对浓度为1.0×10-7g/mL的孔雀石绿溶液进行11次平行测定,相对标准偏差为2.3%。方法可应用于环境水样的测定。     

古紫质等光驱质子泵以及该类活性蛋白质与聚合物的功能复合材料

将具有生物活性的蛋白质与具有良好加工和力学性能的合成高分子相结合制备高性能的杂化材料是材料科学一个新的生长点.本专论聚焦于对具有光驱质子泵功能的两类活性蛋白质——细菌视紫红质(BR)与古紫质4(AR4)的研究,其中BR作为一个著名的膜蛋白已有四十余年的研究历史,而AR4则为中国科研人员十余年前所发现.综述了AR4的研究,并对AR4和BR进行了对比,进一步介绍了光敏蛋白质(BR和AR4)与聚合物基质复合制备新型功能高分子材料的工作,还介绍了该类光敏蛋白质的基因工程改造以及蛋白质/聚合物复合膜用于信息材料方面的探索工作.论文总结了一系列创新成果,如(1)在光敏蛋白质的质子泵机理方面,提出了"弱偶联模型"并解释了AR4具有与BR相反的质子释放和提取时间顺序的内在机理;(2)光敏蛋白质与聚合物复合膜相关的高分子水凝胶和蛋白质聚集状态的研究,并发现与均聚物和两亲性小分子不同,两亲性嵌段共聚物可导致光敏蛋白质中间体的寿命有数量级的延长;(3)发展了光敏蛋白质与聚合物复合膜的制备技术,所得到的材料不仅保持了光学活性,其蛋白质的光学响应性能还得到进一步改善;(4)发现了含光敏蛋白质的紫膜强烈抗拒哺乳动物细胞黏附的新功能;(5)尝试将该蛋白质和聚合物的复合膜作为信息材料,实现了全光宽带图像显示.进一步展望了此类光敏蛋白质的后续研究和潜在的应用前景.     

Regioselective oxyalkylation of vinylarenes catalyzed by diatomite-supported manganese oxide nanoparticles

A regioselective oxyalkylation reaction of vinylarenes with cyclic ethers was developed under the catalysis of a new heterogeneous catalyst, the diatomite-supported Mn(3)O(4) nanoparticles (SMONP-1). The use of this heterogeneous catalyst provided a novel approach for the synthesis of α-carbonyled β-alkylated aryl derivatives via a sp(3) C-H bond functionalization under mild aerobic conditions.     

Polyprenylated Xanthones and Benzophenones from the Bark of Garcinia oblongifolia

A new polyprenylated xanthone (=9H‐xanthen‐9‐one) and a new polyprenylated benzophenone, namely oblongifolixanthone A ( 1 ) and garciniagifolone A ( 2 ), were isolated from the bark of Garcinia oblongifolia, together with five known compounds including the four xanthones 3 – 5 and 7 and a benzophenone 6 . The structures of 1 and 2 were established by detailed analysis of their spectroscopic data, especially 1D‐ and 2D‐NMR spectra and HR‐ESI‐MS data. All these compounds were assayed for their cytotoxic activities against three human tumor cell lines (HeLa, SGC7901, and HepG2). The 1,3,6,7‐tetrahydroxy‐9H‐xanthen‐9‐one ( 3 ) was inactive, and the other compounds showed weak to moderate activity.     

Autocorrelation type,timescale and statistical property in financial time series

Earlier studies have documented that three types of autocorrelations exist in financial time series: sign, volatility, and return autocorrelation. In this paper, we examine how each type of the above autocorrelations affects the statistical properties of financial time series and its role in maintaining such statistical properties. Using three different shuffling series that correspondingly destroy each type of autocorrelation upon different timescales, we find that: (1) the statistical properties of the shuffling series significantly vary from the original ones; (2) volatility and return autocorrelations show greater impacts than sign autocorrelation; (3) the effects on the statistical properties are intensified as time scale expands; (4) the nonlinear component of autocorrelation is the major drive of the effect.     

Semi-global finite-time output feedback stabilization for a class of large-scale uncertain nonlinear systems

This paper addresses the problem of semi-global finite-time decentralized output feedback control for large-scale systems with both higher-order and lower-order terms. A new design scheme is developed by coupling the finite-time output feedback stabilization method with the homogeneous domination approach. Specifically, we first design a homogeneous observer and an output feedback control law for each nominal subsystem without the nonlinearities. Then, based on the homogeneous domination approach, we relax the linear growth condition to a polynomial one and construct decentralized controllers to render the nonlinear system semi-globally finite-time stable.     

原位活体骨铅X射线荧光光谱分析

报道了应用X射线荧光光谱技术在中国本土获得的普通人群原位人体活体骨铅数据,发表了中国大陆普通居民的胫骨和根骨活体骨铅浓度及其研究结果。采用Pb的K系谱线进行了原位活体分析人胫骨和根骨骨铅含量。普通人群样本中所测骨铅含量加权平均值在0.4～22.7μg.(g骨矿物质)-1之间,不确定度在7.0～12.5μg.(g骨矿物质)-1之间,平均最小检出限20.3μg.(g骨矿物质)-1。在污染调查区居民中发现骨铅最高可达73.9μg.(g骨矿物质)-1。     

基于非线性振荡和混沌分析的单相AC-DC变流电路的摄动解析

针对单相交直流全桥变流电路,推导出其在脉宽调制下的连续等效摄动解析模型.首先通过研究非线性振荡过程得到其连续微分方程,该方程含有控制参数和摄动参数.随后通过数学理论证明正则摄动方法能够求出其近似解.求解后对比PSCAD/EMTDC的仿真结果从而验证了解析的正确性.该方法在大规模计算中具有优势.最后分析了控制参数和摄动参数的物理意义,指出这两个参数能够影响变流器的工作状态,甚至引发倍周期混沌.该摄动建模方法不仅适用于单相变流电路,也适用于三相变流电路甚至多相变流电路.     

基于微分同调和混沌分析的集成三相变流电路的降阶方法

本文针对两单元并联集成三相交直流变流电路, 推导出其在正弦脉宽调制 (SPWM) 下的一般仿射方程. 通过微分同调原理得到了降阶化简的判定条件和主要等值参数算法. 通过混沌分析的轨迹图描述了系统参数与不同条件的关系, 并针对该电路进行特征值计算, 证实该方法可以回避特征值的直接求解而降阶系统. 最后, 根据上述参数进行仿真分析, 验证了近似化简方法的有效性和适用范围.     

Synchrotron infrared measurements of dense hydrogen to 360 GPa

Diamond-anvil-cell techniques have been developed to confine and measure hydrogen samples under static conditions to pressures above 300 GPa from 12 to 300 K using synchrotron infrared and optical absorption techniques. A decreasing absorption threshold in the visible spectrum is observed, but the material remains transparent at photon energies down to 0.1 eV at pressures to 360 GPa over a broad temperature range. The persistence of the strong infrared absorption of the vibron characteristic of phase III indicates the stability of the paired state of hydrogen. There is no evidence for the predicted metallic state over these conditions, in contrast to recent reports, but electronic properties consistent with semimetallic behavior are observed.