A Highly Selective and Sensitive Ratiometric Fluorescent Probe for Hypochlorite and Its Application

A novel water-soluble hybrid fluorescein-coumarin dye(FLNC) fluorescence ratiometric probe to recognize OCl^- was designed and synthesized. The most prominent feature of the probe is that the molecular structure contains two different fluorophores, and the fluorescein moiety was connected to coumarin moiety by diacylhydrazine linker. When OCl^- was added, the two fluorophores in the FLNC probe could have a rapid respond simultaneously, with high selectivity and sensitivity towards OCl^- among other reactive oxygen species/reactive nitrogen species(ROS/RNS) and anions, and the detection limit was measured to be 0.30 μmol/L. In addition, the color changes of the solution could be observed by the naked eye and have a short response time(completed within 1 min), which suggestes that the probe FLNC has the potential to be used for real-time detection.     

黄孢展齿革菌对镉离子的吸附

选用黄孢展齿革菌进行生物吸附镉离子的研究。比较多种处理方法发现采用甲醛交联-碱处理能显著提高吸附效果。当溶液pH为4.5,吸附温度为25-35℃,菌丝球粒径在1.5-2.0mm范围内,吸附时间为12h,吸附效果最佳。此时,镉离子浓度从10mg/L下降至0.04mg/L,达到国家污水综合排放标准。此外,该生物吸附过程是由快速吸附和缓慢吸附两个阶段所组成的。     

Biodegradable electrospun poly(l-lactide) fibers containing antibacterial silver nanoparticles

Biodegradable poly(l-lactide) (PLA) ultrafine fibers containing nanosilver particles were prepared via electrospinning. Morphology of the Ag/PLA fibers and distribution of the silver nanoparticles were characterized. The release of silver ions from the Ag/PLA fibers and their antibacterial activities were investigated. These fibers showed antibacterial activities (microorganism reduction) of 98.5% and 94.2% against Staphylococcus aureus and Escherichia coli, respectively, because of the presence of the silver nanoparticles.     

An iterative algorithm to determine the number of time steps in path generation methods

The construction of Brownian motion paths is the most important part of simulation methods for option pricing. Particularly, there are several commonly used path generation methods in the context of quasi‐Monte Carlo, including the standard method and the Brownian bridge method. To apply each method, an inevitable step is to decide how many points are used to discretize the time interval. This paper implements an iterative algorithm to select a suitable number of time steps by successively adding discretization nodes until a specific convergence criterion is met. Numerical results with this algorithm are presented in the valuation of Asian options. Copyright © 2016 John Wiley & Sons, Ltd.     

Aggregation states of rhodamine 6G in electrospun nanofibrous films

Novel fluorescent composite nanofibrous films of rhodamine 6G (Rh6G) and polyacrylonitrile (PAN) are first prepared by electrospinning. The aggregation states of Rh6G in electruspun nanofibrous films are studied as a function of concentrations and characterized by UV–vis absorption spectroscopy and emission and excitation fluorescence spectroscopy. We have also used casting films as reference material to compare the effect of incorporation of Rh6G in electrospun nanofibrous films and casting films. The large specific surface area of the nanofibers and fast evaporation of the solvents in the electrospinning process reduced the aggregation of Rh6G. The appearance of fluorescent J-type dimers, even at higher dye concentration in elctrospun films, demonstrates that the electrospun films are an ideal material for incorporation of fluorescent dyes.     

分光计望远镜与平行光管的共轴调节

目前分光计的调节方法仅能实现望远镜、平行光管的轴线相互平行,但无法实现共轴且垂直相交于中心转轴.这种调节方法虽然不影响夹角的测量,但是无法准确确定光束的传输方向.在本论文中,我们给出了一种调节望远镜、平行光管的轴线共轴且垂直相交中心转轴的方法.     

Variational piecewise constant level set methods for shape optimization of a two-density drum

We apply the piecewise constant level set method to a class of eigenvalue related two-phase shape optimization problems. Based on the augmented Lagrangian method and the Lagrange multiplier approach, we propose three effective variational methods for the constrained optimization problem. The corresponding gradient-type algorithms are detailed. The first Uzawa-type algorithm having applied to shape optimization in the literature is proven to be effective for our model, but it lacks stability and accuracy in satisfying the geometry constraint during the iteration. The two other novel algorithms we propose can overcome this limitation and satisfy the geometry constraint very accurately at each iteration. Moreover, they are both highly initial independent and more robust than the first algorithm. Without penalty parameters, the last projection Lagrangian algorithm has less severe restriction on the time step than the first two algorithms. Numerical results for various instances are presented and compared with those obtained by level set methods. The comparisons show effectiveness, efficiency and robustness of our methods. We expect our promising algorithms to be applied to other shape optimization and multiphase problems.     

A novel approach to prepare silver chloride nanoparticles grown on the surface of PAN nanofibre via electrospinning combined with gas–solid reaction

Well-defined silver chloride nanoparticles grown on the surface of PAN nanofibre were synthesized by electrospinning technology combined with gas–solid reaction. This method can avoid the possibility of the waste of raw material as well as enhance the usage rate of AgNO₃. The PAN nanofibre can be recycled easily. X-ray powder diffraction (XRD) shows the presence of crystal AgCl, X-ray photoelectron spectroscopy (XPS) confirm that there are chemical bonds and interaction between the surface modified PAN nanofibre and Ag ions. This will be propitious to prevent nanoparticles from aggregation. Field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) gave the direct evidence that AgCl nanoparticles have been dispersed on the surface of PAN nanofibre homogeneously.     

Mysovskii-type theorem for the Secant method under Hölder continuous Fréchet derivative

The Mysovskii-type condition is considered in this study for the Secant method in Banach spaces to solve a nonlinear operator equation. We suppose the inverse of divided difference of order one is bounded and the Fréchet derivative of the nonlinear operator is Hölder continuous. By use of Fibonacci generalized sequence, a semilocal convergence theorem is established which matches with the convergence order of the method. Finally, two simple examples are provided to show that our results apply, where earlier ones fail.     

Chemical variation in lipophilic composition of Lamiophlomis rotata from the Qinghai-Tibetan Plateau

Lipophilic extracts from flowers, leaves, and roots of Lamiophlomis rotata (Benth.) were analyzed using GC-MS. A total of 67 compounds were identified. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 423–425, September–October, 2006.