β－环糊精衍生物的合成及对脲酶的抑制作用

β┐环糊精衍生物的合成及对脲酶的抑制作用＊丁志刚任维衡习玲玲罗天顺宋发军（中南民族学院化学系，武汉４３００７４）关键词β－环糊精，衍生物，脲酶，配合物近年来，随着生物医学工程的迅速发展，新型医用级吸附树脂的研制取得了较大进步．其中有关铵离子和尿素的吸...     

多波长线性回归—导数分光光度法同时测定镍,铜,钒三组分混合物

用5-Br-PADAP做显色剂,采用多波长线性回归-导数分光光度法同时测定镍、铜、钒。该法灵敏、准确。与CPA矩阵等方法相比,由于不需进行矩阵运算,只进行简单的数学处理,因而更方便。     

Global existence for the derivative nonlinear Schrödinger equation by the method of inverse scattering

We develop inverse scattering for the derivative nonlinear Schrödinger equation (DNLS) on the line using its gauge equivalence with a related nonlinear dispersive equation. We prove Lipschitz continuity of the direct and inverse scattering maps from the weighted Sobolev spaces H^2,2(?) to itself. These results immediately imply global existence of solutions to the DNLS for initial data in a spectrally determined (open) subset of H^2,2(?) containing a neighborhood of 0. Our work draws ideas from the pioneering work of Lee and from more recent work of Deift and Zhou on the nonlinear Schrödinger equation.     

Synthesis of magnetic γ-Fe2O3-based nanomaterial for ultrasonic assisted dyes adsorption: Modeling and optimization

γ-Fe₂O₃ nanoparticles were synthesized and loaded on activated carbon. The prepared nanomaterial was characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transforms infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The γ-Fe₂O₃ nanoparticle-loaded activated carbon (γ-Fe₂O₃-NPs-AC) was used as novel adsorbent for the ultrasonic-assisted removal of methylene blue (MB) and malachite green (MG). Response surface methodology and artificial neural network were applied to model and optimize the adsorption of the MB and MG in their individual and binary solutions followed by the investigation on adsorption isotherm and kinetics. The individual effects of parameters such as pH, mass of adsorbent, ultrasonication time as well as MB and MG concentrations in addition to the effects of their possible interactions on the adsorption process were investigated. The numerical optimization revealed that the optimum adsorption (>99.5% for each dye) is obtained at 0.02 g, 15 mg L⁻¹, 4 min and 7.0 corresponding to the adsorbent mass, each dye concentration, sonication time and pH, respectively. The Freundlich, Langmuir, Temkin and Dubinin–Radushkevich isotherms were studied. The Langmuir was found to be most applicable isotherm which predicted maximum monolayer adsorption capacities of 195.55 and 207.04 mg g⁻¹ for the adsorption of MB and MG, respectively. The pseudo-second order model was found to be applicable for the adsorption kinetics. Blank experiments (without any adsorbent) were run to investigate the possible degradation of the dyes studied in presence of ultrasonication. No dyes degradation was observed.     

On the differential properties of the support function of the∈-subdifferential of a convex function

We study differential properties of the support function of the-subdifferential of a convex function; applications in algorithmics are also given.     

导数光谱法络合物稳定常数的测定

本文利用导数光谱法消除体系中共存有关物种干扰,直接测定游离配体浓度。基于此仿照对应溶液法的图解法,我们拟订两个测定络合物稳定常数的新方法。方法简便可靠,试用于La-BPR体系获得了令人满意结果。     

导数光谱法测定松香中枞酸和脱氢枞酸

本文用导数光谱法对松香中枞酸和脱氢枞酸的测定进行了方法研究和比较,并用四阶导数光谱对几种不同松香中枞酸和脱氢枞酸进行了同时测定,结果令人满意。该法灵敏度高,能较好地消除背景干扰。相对标准偏差0.17％;枞酸回收率99.17％;脱氢枞酸回收率96.27％。     

导数技术在植物叶片荧光研究中的应用

本文首次采用导数技术于植物叶片的活体叶绿素荧光性质研究,探讨了其生物学意义。该方法降低了不同叶绿素存在形式光谱干扰程度,提高了谱带分辩率。衰老期植物叶片的导数荧光光谱和常规荧光光谱相比,对叶衰老的敏感程度增加,导数技术的应用便于植物状态的评估。     

Thematization of derivative schema in university students: nuances in constructing relations between a function's successive derivatives

This study is part of a more extensive research project that addresses the understanding of the derivative concept in university students with prior instruction in differential calculus. In particular, we focus on the analysis of students’ responses to a sequence of tasks that require a high level of understanding of the concept, and complement this information with clinical interviews. APOS (Action-Process-Object-Schema) theory and the configuration of the derivative concept that is characterized by: mathematical elements, logical relations and the representation modes that students use to solve a task were used in the analysis of students’ responses. The results obtained suggest that thematizing the derivative schema is difficult to achieve. In addition, nuances were observed in responses given by those students who succeeded, indicating differences in the construction of relations between the successive derivatives of a function.     

壳聚糖及其衍生物在化妆品中的应用

从壳聚糖及其衍生物的性能以及适用于化妆品的特性出发,讨论了壳聚糖及其衍生物在化妆品中的广泛应用。