铜(Ⅱ)--二肽配合物的配位形式、结构和稳定性研究进展

本文概述了近几十年来铜(Ⅱ)—二肽配合物的研究进展,介绍了铜(Ⅱ)—二肽体系几种常见的配位方式,以及溶液和晶体中的二肽铜配合物的结构。对配合物的稳定性进行了讨论,着重介绍了二肽的光学异构对配合物稳定性的影响。     

硫代乙酰胺体系电沉积法制备CdS纳米膜

The film of surface active agents spread out on the surface of the electrolyte of Thioacetamide and cadmium chloride. CdS nanofilm was deposited at the interface of surface active agents and electrolyt by the method of electrodeposition. The optimal conditions on which the nanofilm was prepared of the least crystals and uniform particles could be attained via analytical results of L₁₆(4⁵) orthogonal experiments. The optimal conditions: castor oil/hexadecanoll 0.06 mL·cm^-2，CdCl₂/CH₃CSNH₂ 4 mmol·L^-1, cell voltage 5 V, electrodeposition temperature 15 ℃. The effects on the grain size of temperature, surface-active agent, electrodyte concentration, cell voltage and pH become smaller in the series. If the temperature was high, the movement of molecules of surface-active agent and electrodyte would be faster, thus the preparation of the film would be difficult. The grain size of thinfilm varied with the surface-active agents, however, when the amount of surface-active agents reached a certain value, the grain size would remain unchanged. The higher the electrodyte concentration, the larger the grain size of nanofilm. The surface forms were changed at the same time. If the pH of the electrodyte was higher or lower, nanofilm could not be prepared successfully, thus the pH range should be is 3～6. SEM image of the nanofilm shows the occurance of dendrite. The sucessful preparation of nanofilm is closely related to the nature of surface activre agent due to the nanofilm growth mechanism.     

神经网络在挠性陀螺仪伺服回路故障诊断中的应用

本文用BP神经网络对挠性陀螺仪伺服回路的故障诊断进行了模拟,取得了满意的结果.同时还介绍了作者设计的这一通用型BP神经网络软件包及其特色.     

动脉中非平稳流动壁面剪切力及其Hilbert-Huang变换

本文通过数值方法求解均匀动脉中的非平稳脉动流,给出了通过测量非平稳脉动血流量确定壁面切应力的方法.作为算例,采用实测的大鼠颈总动脉流量信号,求出了均匀动脉壁面切应力波形.进一步对求得的切应力波形进行经验模态分解(EMD),得到了切应力波形的各内在模态(IMF),以及Hilbert幅值谱.从切应力波形经Hilbert-Huang变换得到的IMF和Hilbert谱图可以明显地看出切应力各频率成分的物理意义.所得结果为进一步深入研究非平稳脉动切应力与血管重建的关系提供了一种方法学基础.     

CONSERVATION OF ENDANGERED ENDEMIC SEABIRDS WITHIN A MULTI‐PREDATOR CONTEXT: THE BARAU'S PETREL IN RÉUNION ISLAND

Abstract Seabirds breeding on islands are vulnerable to introduced predators, such as rats and cats, and the removal of such predators is generally viewed as a priority for seabird conservation and restoration. However, multiple invasive mammal species interacting may generate unexpected outcomes following the removal (eradication) of one species. Generally these indirect interactions are not well understood or demonstrated. We propose and study a prey (seabird)‐mesopredator (rat)‐superpredator (cat) model, taking into account the juvenile stages in the prey population, in order to direct conservation management for seabird conservation. We give a more biologically realistic differential system than those studied before (Courchamp et al. [1999] ; Fan et al. [2005] ), in particular for long‐lived seabird species. We present a theoretical study and show existence and uniqueness of a positive solution as well as a qualitative study of the equilibria that may appear. Because standard numerical methods, usually implemented in scientific softwares, can fail to give the right biological approximations ( Anguelov et al. [2009] ), we propose a reliable algorithm that preserves most of the qualitative properties of the continuous system, using the theory of nonstandard finite difference methods. Finally, we use biologically realistic parameters available for the representative Barau's petrel (Pinet et al. [2008] ), an endemic species from Réunion island, to present numerical simulations that support the theoretical study. Cats play the major role in seabird prey population dynamics. Seasonality in seabird breeding delays but does not prevent extinction. In all scenarios, cat control (or preferably eradication) is imperative to prevent extinction of vulnerable long‐lived seabirds, like the Barau's petrel.     

Suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.     

Synthesis, Characterization, Crystal Structure and Stability of a Ternary Cu(Ⅱ) complex with 1,10-Phenanthroline and L-Valinate

Introduction It is important to research the mixed-ligand copper complexes containing bioligands,such as amino acids, nucleic acids and proteins,in exploring the functional mechanism of microelement copper in organism because the reaction of any micronutrient with two or more bioligands in the concentrated bioligands background gives mixed-ligand ternary complexes, which are more stable[1]and related with storage of substance and transportation of metal ions in the life process.     

γ-Al2O3负载Cr促进SO2-4/ZrO2固体超强酸研究

将Ｃｒ促进的ＳＯ＾２－４／ＺｒＯ２（ＳＺ）固体超强酸Ｃｒ－ＳＺ负载于γ－Ａｌ２Ｏ３载体上,制成Ｃｒ－ＳＺ／Ａｌ２Ｏ３系列固体超强酸,利用探针反应考察了其超强酸性,中强酸性和弱酸性的变化情况,详细研究了样品的比表面、硫含量、ＺｒＯ２晶化情况及正丁烷低温异构化反应活性,结果发现,负载后部分Ｃｒ－ＳＺ的正丁烷低温异构化反应活性显著提高,含铬样品酸强度和脱氢性能的增强对其正丁烷异构化反应活性的提高均有贡献,样品酸性和脱氢性之间的合适匹配使Ｃｒ－ＳＺ／Ａｌ２Ｏ３显示出很高的正丁烷异构化反应活性。     

晶态-非晶态复合锂离子导体的电学性质

本文研究了晶态LiCl-非晶态Li₂O·3B₂O₃复合锂离子导体的电学性质。实验发现这种晶态-非晶态新型复合离子导体的电学性质变化具有新的现象,即在宏观电导率σ_m-组成曲线上出现了电导率增加的“双峰”效应。相应地,在表观活化能E_m-组成曲线和介电常数ε_m-组成曲线上出现了“双谷”。本文还详细讨论了这些实验现象,得到了与理论相符合的结果。 关键词：