Theoretical Study on One- and Two-Photon Absorption Properties of PPV Derivative with Electron-Donor Phenylanthracene as Pendent Group

Based on the equilibrium structures from quantum mechanics AM1 method, employing INDO/CI method and the sum-over-state （SOS） formula, the one-photon absorption （OPA） and two-photon absorption （TPA） properties as well as the second hyperpolarizabilities were discussed in detail for a kind of PPV derivative poly 2-（9-phenylanthracen-10-yl）-1,4-phenylenevinylene （P1）. The results indicate that the two-photon cross section （3） increases with the increasing of the number of repeating segment （n）, however only a slight increase corresponds to the increasing of molecular weight when the repeating unit number arrives at a certain number. From this point of view, the TPA cross section values of P1 were extrapolated through the linear fit of 3 value vs. 1/n. The δ value of P1 is as high as 181 GM （1 GM=10^-50 cm^4·s·photon^-1）. Concerning the influence of pendent group and extension of π-conjugation on 3 values, another four oligomers P2, PPV, P1-1, and P2-1 were investigated for comparison. The calculation results reveal that the position and property of pendent group have great influence on the OPA and TPA properties. A most crucial role for relatively larger 3 value was played by the extension of π-conjugation.     

基于吡咯并四硫富瓦烯结构的D-π-A型化合物的合成及其非线性光学性质的理论计算

以吡咯并四硫富瓦烯衍生物(1)为原料,经过Vilsmeier甲酰化、Wittig反应或交叉偶联反应得到D-π-A型化合物(6a,7a),为了比较N-甲基的影响,以N-甲基吡咯并四硫富瓦烯衍生物(2)出发,用同样的方法合成了N-甲基化的D-π-A型化合物(6b,7b). 用循环伏安法(CV)和UV-Vis研究了目标化合物的电化学和光物理性质,并进行了非线性光学性质的理论计算. 结果表明,目标化合物的紫外最大吸收波长在325～383 nm之间,具有较长共轭结构的化合物7a和7b显示出较好的三阶非线性光学性质, 它们在λ=1 064 nm基频下的三阶非线性系数γ值达5×10-33 esu.     

离子交换色谱测定原油中的单双石油磺酸盐

建立了一种新的离子交换高效液相色谱在线测定原油中单双石油磺酸盐的方法,通过使用六通阀切换,在一根强阴离子交换柱上完成在线纯化和分离。原油样品经过二氯甲烷-甲醇(体积比60∶40)溶剂稀释后进入HPLC测定。原油中单石油磺酸盐的检出限为10.0μg/g,双石油磺酸盐的检出限为12.5μg/g。2-萘磺酸钠和萘-1,5-二磺酸钠分别在4.8~120.0 mg/L和4.0~100.1 mg/L范围内有良好的线性。该方法准确、重复性好,可以满足原油中石油磺酸盐的分离测定。     

基于马尔可夫随机场的改进Metropolis混凝土CT的图像分割方法

提出一种基于马尔可夫随机场改进的Metropolis模拟退火算法.该算法中阈值α的选取优化了Metropolis算法.根据Beyes理论将图像分割问题转化为最大后验概率求取问题,并给出了参量预测算法.在实验中,将本文提出的算法与ICM、传统的Metropolis和Gibbs采样模拟退火算法进行比较.结果表明改进的Metropolis算法在图像分割效率和分割准确度上都有明显的提高.通过混凝土CT图像分割实验,改进Metropolis的应用能够较完整地反映出混凝土材料的内部结构和缺陷.     

金银花绿原酸提取方法研究

采用高效液相色谱法测定金银花中绿原酸的含量,通过热回流法优化金银花绿原酸提取条件并进行正交试验分析. 试验结果表明,金银花中绿原酸最佳提取条件为乙醇体积分数80%、提取温度100 ℃、料液比1∶20 （g/mL）、提取时间2 h时,绿原酸提取率为7.1%. 方法分析准确、操作简便、设备要求低,可用作金银花的质量控制和开发利用.     

Demodulation of acoustic telemetry binary phase shift keying signal based on high-order Duffing system

In order to grasp the downhole situation immediately, logging while drilling(LWD) technology is adopted. One of the LWD technologies, called acoustic telemetry, can be successfully applied to modern drilling. It is critical for acoustic telemetry technology that the signal is successfully transmitted to the ground. In this paper, binary phase shift keying(BPSK) is used to modulate carrier waves for the transmission and a new BPSK demodulation scheme based on Duffing chaos is investigated. Firstly, a high-order system is given in order to enhance the signal detection capability and it is realized through building a virtual circuit using an electronic workbench(EWB). Secondly, a new BPSK demodulation scheme is proposed based on the intermittent chaos phenomena of the new Duffing system. Finally, a system variable crossing zero-point equidistance method is proposed to obtain the phase difference between the system and the BPSK signal. Then it is determined that the digital signal transmitted from the bottom of the well is ‘0' or ‘1'. The simulation results show that the demodulation method is feasible.     

预付款融资下基于改进收益共享与回购联合契约的双渠道供应链协调研究

随机需求下,考虑了制造商存在资金约束的双渠道供应链在采用预付款融资时,如何实现供应链协调的问题。在制造商为主方的Stackelberg博弈下,研究了制造商和零售商分散决策时的最优库存决策问题,并通过设计改进收益共享与回购联合契约使得供应链达到协调。在此基础上,讨论了供应链的帕累托改进区间。最后,通过算例验证了联合契约对双渠道供应链协调及帕累托改进的有效性,并分析了契约参数和融资参数对供应链的影响。     

微囊藻毒素-LR的特征红外光谱

利用傅里叶变换红外(FTIR)光谱仪研究了微囊藻毒素-LR在扫描范围4 000～600 cm-1的红外吸收光谱图,微囊藻毒素-LR分子构成中的主要官能团,如带有单一取代基的苯环、胍基、γ-羧基等特征红外吸收带在谱图上均得到了确认。     

高效液相色谱法分离蛋白质的大孔硅质固定相的制备及分离机理

介绍了不同孔径的大孔硅胶基质的制备，二醇基和氨基固定相的合成，及其蛋白质的分离特性。探讨了流动相中的盐浓度和pH对蛋白质保留时间的影响，以及在此两种固定相上蛋白质分离机理的比较。由于大孔填料具有小的比表面积、往容量也低，从而有利于作蛋白质等生物大分子的高效快速分离分析。     

例析智慧课堂下数学教学的有效提升

基于建构主义学习理论,结合智慧课堂优势,立足教材内容、授课班级学情、学生预习反馈的总体分析,确定教学方式、教学资源以及时间分配.借助智慧课堂优势,在与学生立体互动的交流过程中,用问题驱动学生主动类比思考、积极探索,形成对知识的深度理解,逐步发展学生数学素养,以期达到课堂效率的有效提升.