On the semilocal convergence behavior for Halley’s method

The present paper is concerned with the semilocal convergence problems of Halley’s method for solving nonlinear operator equation in Banach space. Under some so-called majorant conditions, a new semilocal convergence analysis for Halley’s method is presented. This analysis enables us to drop out the assumption of existence of a second root for the majorizing function, but still guarantee Q-cubic convergence rate. Moreover, a new error estimate based on a directional derivative of the twice derivative of the majorizing function is also obtained. This analysis also allows us to obtain two important special cases about the convergence results based on the premises of Kantorovich and Smale types.     

Hydrothermal etching assisted crystallization: a facile route to functional yolk-shell titanate microspheres with ultrathin nanosheets-assembled double shells

We report a facile "hydrothermal etching assisted crystallization" route to synthesize Fe(3)O(4)@titanate yolk-shell microspheres with ultrathin nanosheets-assembled double-shell structure. The as-prepared microspheres possess a uniform size, tailored shell structure, good structural stability, versatile ion-exchange capability, high surface area, large magnetization, and exhibit a remarkable catalytic performance.     

Highly Ordered Mesoporous Tungsten Oxides with a Large Pore Size and Crystalline Framework for H2S Sensing

An ordered mesoporous WO₃ material with a highly crystalline framework was synthesized by using amphiphilic poly(ethylene oxide)‐b‐polystyrene (PEO‐b‐PS) diblock copolymers as a structure‐directing agent through a solvent‐evaporation‐induced self‐assembly method combined with a simple template‐carbonization strategy. The obtained mesoporous WO₃ materials have a large uniform mesopore size (ca. 10.9 nm) and a high surface area (ca. 121 m² g^?1). The mesoporous WO₃‐based H₂S gas sensor shows an excellent performance for H₂S sensing at low concentration (0.25 ppm) with fast response (2 s) and recovery (38 s). The high mesoporosity and continuous crystalline framework are responsible for the excellent performance in H₂S sensing.     

Synthesis of silica nanospheres with Ni2+-iminodiacetic acid for protein separation

Silica (SiO₂) nanospheres (NSs) with immobilized metal ligands have been prepared for the affinity separation of proteins. First, SiO₂ NSs were prepared by controlled hydrolysis of tetraethoxysilane in a basic aqueous-ethanol solution. Then through reaction of iminodiacetic acid (IDA) with 3-glycidoxypropyltrimethoxysilane and immobilization of them onto the surfaces of above SiO₂ NSs, novel affinity adsorbents with IDA chelating groups were obtained. After chelating Ni²⁺ ions, the SiO₂–IDA–Ni²⁺ NSs were applied to separate his-tagged proteins directly from the mixture of lysed cells. The SiO₂–IDA–Ni²⁺ NSs present negligible nonspecific protein adsorption and high protein binding ability (28.3 mg/g).     

水介质初始参数设置对水下爆炸载荷的影响

针对数值计算中水介质初始参数设置对水下爆炸载荷特性的影响开展了深入分析。基于参考状态参数确定了水介质状态方程形式;从热力学角度分析了常用的两种初始参数设置方式,提出了一种按等温假设设置初始参数的方式,并对LS-DYNA中INITIAL_EOS_ALE关键字给出的参数设置结果进行了分析;采用LS-DYNA程序进行一维球形装药水下爆炸数值计算,分析了3种设置方式下爆炸载荷特性的差异,并与已有研究成果进行了对比。结果表明:当仅改变水介质内能项时,参数按等容过程变化,流场压力源于外界传热,与实际深水环境严重不符;INITIAL_EOS_ALE关键字给出的参数设置结果与仅改变水介质密度（等内能过程）接近,水温变化规律与真实环境不符;按等内能过程和等温过程设置初始参数时,水下爆炸载荷特性计算结果基本相同,与已有成果吻合;综合分析认为,按等温形式进行初始参数设置方式较优。研究成果可为水下爆炸尤其是深水爆炸数值仿真提供参考。     

Free-standing anion-exchange PEO–SiO2 hybrid membranes

Free-standing anion-exchange polyethylene oxide (PEO)–SiO₂ hybrid membranes with higher flexibility and good mechanical strength (tensile strength (TS) as high as 20.55 MPa) as well as high temperature tolerance (thermal degradation temperature in air, T_d, in the range of 220–240 °C) were prepared through sol–gel reaction of different precursors: charged alkoxysilane-functionalized PEO-1000 (PEO-[Si(OCH₃)₃]₂(+)), N-triethoxysilylpropyl-N,N,N-trimethylammonium iodine (A-1100(+)), monophenyltriethoxysilane (EPh) and in some cases also tetraethoxysilane (TEOS). Properties of the hybrid membranes, such as the thermal stability, tensile properties, hydrophilicity, and electrical performances, can be controlled by changing the feed ratio of the different sol–gel precursors. The results showed that some of the membranes have relatively good conductivity (∼0.003 S/cm) and so may find potential applications in alkaline membrane fuel cells.     

无味红霉素的极谱研究及应用

无味红霉素是一种广谱临床抗生素,其分析方法已见报道的有薄层分离、生物自显影法和分光光度法。本文首次研究了无味红霉素的单扫极谱测定法,方法灵敏度可达0.05μg/mL,应用于血清和片剂分析,结果令人满意。并对极谱波性质作了初步探讨。 1 实验部分     

Microporous Silica-supported Poi yoxometal ate Catalyst H3PW12O400/SiO2 with High Activity for Acetal Reaction between Benzaldehyde and Ethylene Glycol

Keggin-type polyoxometalates (POMs) whose representative is H3PW12O40(PW12) exhibits a unique combination of physical and chemical properties. They have been widely used as acid catalysts in homogeneous and heterogeneous reaction systems. However, the catalytic activity of PW12 is so limited due to its very low specific surface area (≤9 m2/g)[1] that polar molecules can only react on its surface.     

EXISTENCE OF POSITIVE PERIODIC SOLUTION OF MUTUALISM SYSTEM WITH INFINITE DELAYS

In this paper, by using Mawhin coincidence degree, some sufficient conditions are obtained for the global existence of positive periodic solution of a mutualism system with infinite delays. Our results generalize those of Yang etc. [8] and Gopalsamy and He [7].