Ag_2S/CdS复合物的制备及甲基橙降解性能

以硝酸镉、硝酸银及硫脲为镉源、银源和硫源,用水热法在水溶剂中合成CdS、Ag2S和Ag2S/CdS复合材料,采用XRD对复合材料进行表征。另外,还探讨了照射时间、焙烧温度、焙烧时间、催化剂的用量、初始浓度等变化条件下对甲基橙降解的影响。结果表明:催化剂的量为1.00g·L-1、染料初始浓度为10.00mg·L-1时,Ag2S/CdS(55)、焙烧温度为400℃,焙烧时间为90min和超声波清洗器的功率为50 W时,对甲基橙染料的降解效果最佳。     

Fast filtering algorithm based on vibration systems and neural information exchange and its application to micro motion robot

This paper develops a fast filtering algorithm based on vibration systems theory and neural information exchange approach. The characters, including the derivation process and parameter analysis, are discussed and the feasibility and the effectiveness are testified by the filtering performance compared with various filtering methods, such as the fast wavelet transform algorithm, the particle filtering method and our previously developed single degree of freedom vibration system filtering algorithm, according to simulation and practical approaches. Meanwhile, the comparisons indicate that a significant advantage of the proposed fast filtering algorithm is its extremely fast filtering speed with good filtering performance. Further, the developed fast filtering algorithm is applied to the navigation and positioning system of the micro motion robot, which is a high real-time requirement for the signals preprocessing. Then, the preprocessing data is used to estimate the heading angle error and the attitude angle error of the micro motion robot. The estimation experiments illustrate the high practicality of the proposed fast filtering algorithm.     

非标记型双底物检测核酸适配体传感器研究

采用电沉积法制备了铁氰化镍(NiHCF)氧化还原电化学探针, 以金纳米粒子(GNPs)为固定核酸适配体的载体构建了非标记型测定凝血酶(TB)和腺苷(AD)的核酸适配体传感器. 采用循环伏安法(CV)和SEM对NiHCF膜进行了表征; 利用电化学阻抗(EIS)对传感器的组装过程进行了监测; 用CV和差分脉冲伏安法(DPV)对该传感器的电化学行为进行了研究. 该传感器对凝血酶的检测在1.0 fg·mL^-1～1.0 μg·mL^-1范围内成良好的线性关系, 相关系数为0.997, 检测限为0.27 fg·mL^-1; 对腺苷的检测在1.0 fg·mL^-1～1.0 ng·mL^-1范围内成良好的线性关系, 相关系数为0.997, 检测限为0.36 fg/mL. 该传感器制备简单, 灵敏度高, 抗干扰能力强.     

CFD simulation of particle suspension in a stirred tank

Particle suspension characteristics are predicted computationally in a stirred tank driven by a Smith turbine. In order to verify the hydrodynamic model and numerical method, the predicted power number and flow pattern are compared with designed values and simulated results from the literature, respectively. The effects of particle density, particle diameter, liquid viscosity and initial solid loading on particle suspension behavior are investigated by using the Eulerian–Eulerian two-fluid model and the standard k–? turbulence model. The results indicate that solid concentration distribution depends on the flow field in the stirred tank. Higher particle density or larger particle size results in less homogenous distribution of solid particles in the tank. Increasing initial solid loading has an adverse impact on the homogeneous suspension of solid particles in a low-viscosity liquid, whilst more uniform particle distribution is found in a high-viscosity liquid.     

二次电子衬度曲线法研究PVC/MBS共混物断面的分形特征

利用二次电子衬度曲线法测定了聚氯乙烯甲基丙烯酸甲酯丁二烯苯乙烯共聚物(PVCMBS)共混物冲击断面的形貌特征及对应的分形维数值.结果表明,材料的断口或微观结构并不是严格的分形结构,这种自相似性仅存在于一定尺码范围内,不同断面形貌特征所对应的分形维数测量值不同,随着MBS用量增加,PVCMBS共混物缺口冲击强度随满足自相似原理的形貌特征所对应的分形维数值增大而增大.本文从理论上讨论了材料断裂韧性与分形维数的关系.     

武威医用重离子加速器同步环的准直安装

武威医用重离子加速器是目前世界上最紧凑的重离子加速器治癌装置,同步环周长小至56.1 m,其中很多关键元件的安装定位精度要求达到亚毫米量级,四极透镜的定位精度要求0.1 mm。结合激光跟踪仪的特点和测量学知识通过三维控制网及多重坐标系的转换,探索了一种在元件自身坐标系下调节准直的方法,提高了准直安装的工作效率,使得最后所有的元件安装各向误差均控制在0.1 mm以内,其结果优于该装置的精度要求,使得同步环在短时间内顺利调束成功,从而验证了同步环准直测量的可靠性与准确性。Wuwei Heavy ion medical machine (HIMM) is the most compact accelerator facility for heavy ion therapy in the world,which has a circumference about 56.1 m.The alignment accuracy of many components of the machine should be submillimeter level.For example,the positioning accuracy of quadrupoles should be within 0.1 mm according to design target.With the combination of laser tracker and surveying knowledge,we develop a method that adjusts and collimates elements under the elements themselves coordinates via three-dimensional control network and the transformation of multiple coordinates to improve the efficiency of installation alignment.By this way,the deviation of each direction from all elements is under 0.1 mm and the result is better than the design target,which leads to the successful commission of Wuwei HIMM.Consequently,the feasibility of this method developed is verified.     

3,3-双(N-辛基-2-甲基吲哚)邻苯二甲内酯荧烷在乙醇溶液中的显色性能

测试了3,3-双(N-辛基-2-甲基吲哚)邻苯二甲内酯荧烷(ck-16)在显色前后的¹³C NMR谱图,揭示了其显色前后的结构变化及其显色机理。 利用紫外可见吸收光谱法研究了ck-16在乙醇溶液中与不同显色剂作用后的光谱性质,测定了其与常用显色剂间的络合比和不稳定常数,并进一步研究了外界条件的改变对ck-16在乙醇溶液中与特定显色剂作用后显色性能的影响。 研究发现,亲电阳离子进攻ck-16荧烷分子的苯酞环,使苯酞环断裂,推电子的N原子和吸电子的羰基O原子之间建立π电子迁移通道使分子显色。 在乙醇介质中,ck-16与不同显色剂作用后具有不同的显色效果;对路易斯酸和有机弱酸这两类显色剂而言,ck-16与所测的四种显色剂(FeCl₃、草酸、CuCl₂、水杨酸)均以1:1的形式络合,ck-16与Fe³⁺的不稳定常数最小,结合最稳定,草酸其次,与Cu²⁺的相近,ck-16与水杨酸的结合最弱;在乙醇中,放置时间对ck-16/FeCl₃和ck-16/H₂C₂O₄两个体系的吸光度影响不大,但两体系表现出随水含量变化不同的敏感性,ck-16/FeCl₃体系具有比ck-16/H₂C₂O₄体系更为灵敏和快速的水致褪色性能。     

表面引发原子转移自由基聚合法合成无机/有机核壳复合纳米粒子

原子转移自由基聚合(ATRP)是目前为止最具工业化应用前景的活性/可控自由基聚合方法之一,其最大特点是可以得到分子量分布窄、链结构规整的聚合物,而且可聚合的单体种类多,反应条件温和并易控制。表面引发ATRP(SI-ATRP)特别适合于无机材料表面接枝聚合物或无机/有机复合材料的制备,近年来引起了国内外研究者的高度关注。本文首先对SI-ATRP的反应过程与特点做了阐述,然后重点述评了用SI-ATRP法合成以非金属氧化物纳米粒子、金属氧化物纳米粒子、金属纳米粒子或其他无机纳米粒子为核的无机/有机复合纳米粒子的研究进展,最后对未来用SI-ATRP法合成无机/有机复合纳米粒子的发展方向和研究前景进行展望。     

Lebesgue constants of Gaussian cardinal interpolation operators from l (ℤ) into L (ℝ)

Summary In recent years, with the attention to the radial-basis function by mathematicians, more and more research is concentrated on the Gaussian cardinal interpolation. The main purpose of this paper is to discuss the asymptotic behavior of Lebesgue constants of the Gaussian cardinal interpolation operator ℒ_λ from l (ℤ) into L (ℝ), that is, ∥ℒ_λ∥₁. We obtain the strong asymptotic estimate of the Lebesgue constants which improves the results of Riemenschneider and Sivakumar in [11].