A simple and an efficient strategy to synthesize multi-component nanocomposites for biosensor applications

We demonstrate that core–shell multi-component nanocomposites can be grown in situ at room temperature by a novel one-step approach without adding any reductant and stabilizer. We have presented a one-step method for the synthesis of multi-component nanocomposites in water solution, the multi-component nanocomposites could be produced directly and quickly in an in situ wet-chemical reaction. Here, Au–polypyrrole (PPy)/Prussian blue (PB) nanocomposites have been synthesized successfully under the same circumstance. With the addition of pyrrole monomers into mixture solutions, the autopolymerization of pyrrole into PPy and AuCl₄⁻ was reduced to elemental Au instantaneously as well as simultaneously. At the same time, PB produced along with elemental Au serving as a catalyst. Furthermore, we investigated the performance of Au–PPy/PB nanocomposites as amperometric sensor toward the reduction of H₂O₂, which displayed high sensitivity, fast response and good stability. The peak current of H₂O₂ increased linearly with the concentration of H₂O₂ in the range from 2.5 × 10⁻⁹ to 1.2 × 10⁻⁶ M, and the low detection limit of 8.3 × 10⁻¹⁰ M (S/N = 3) was obtained. Therefore, this work provides a new pathway to design and fabricate novel multi-component nanocomposites, which have unique characteristics and hold great applications in the fields of sensors, electrocatalysis and others.     

Two numerical methods for a Cauchy problem for modified Helmholtz equation

We consider a Cauchy problem for the modified Helmholtz equation. A conditional stability estimate is proved. Two order optimal regularization methods and error estimates are investigated. Numerical experiment shows that these methods work well.     

e~＋－Kr和e~＋－Xe弹性散射截面的模型势计算

用模型势方法计算了低能正电子与Ｋｒ、Ｘｅ原子弹性散射总截面与动量转移截面，并将本文的计算结果与理论计算及实验值作了比较。     

The complete synchronization of Morris–Lecar neurons influenced by noise

The influence of noise on the complete synchronization in a Morris–Lecar (ML) model neuronal system is studied in this work. Two individual ML neurons with different initial conditions can discharge completely synchronously when the noise intensity is large enough, and for a smaller reversal potential (V _Ca), the uncoupled neuronal system could be induced to a complete synchronization state under smaller noise intensity. Two coupled ML neurons could be synchronized under very small noise intensity even in the case of weak coupling, the synchronization characteristics of the two coupled neurons are discussed by analyzing the Similarity Function (S(0)) of their membrane potentials, which proves that noise can promote the complete synchronization. The critical noise intensity (D _j ) to induce complete synchronization in coupled ML neurons will decrease with the increase of V _Ca. This result is helpful to study the synchronization and the code of a neural system.     

GC Analysis of the Fatty Acid Composition of Yak Kidney

To obtain valuable information for development of potential commercial products from yak kidney, which is usually treated as waste, the fatty acid composition of kidneys from yak reared in Gansu province, China, was investigated by gas chromatography. Fifteen different fatty acids were identified. The major fatty acids are oleic acid (33.3%), stearic acid (20.2%), and palmitic acid (18.4%). More interestingly, several important and essential fatty acids were also identified, including conjugated linoleic acid (2.94%), omega-3 fatty acids, for example docosahexaenoic acid (1.47%), eicosapentaenoic acid (1.11%) and alpha linolenic acid (0.37%), and omega-6 fatty acids, for example arachidonic acid (2.86%) and linoleic acid (1.98%). The results show that the fatty acid composition of yak kidney is of reasonable value and is suitable for further development of possible commercial products. This is the first report of the fatty acid profile of yak kidney.

     

Highly efficient oxidation of alcohols using Oxone as oxidant catalyzed by ruthenium complex under mild reaction conditions

Aromatic and alkyl alcohols were oxidized to the corresponding aldehydes or ketones at room temperature with high conversion and selectivity using Oxone （2KHSOs-KHSO4.K2SO4） as oxidant catalyzed by ruthenium complex Quin-Ru-Quin （where Quin = 8-hydroxyquinoline）. The reaction time is very short and the preparation of complex is simple.     

Optimal birth control of free horizon problems for predator-prey system with age-structure

We study optimal birth policies for three age-dependent populations in a predator-prey system, which is controlled by fertility. New results on problems with free final time and integral phase constraints are presented, the approximate controllability of system is discussed.     

Synthesis and decoloration capacity of well-defined and PMMA-grafted palygorskite nanocomposites

Structurally well-defined PMMA-grafted palygorskite nanoparticles were prepared by modifying the surface of palygorskite nanoparticles with initiators for reverse atom transfer radical polymerization (reverse ATRP) and by using these initiator-modified nanoparticles as macroinitiators. Reverse ATRP from palygorskite nanoparticles was then performed to attach well-defined polymer on to an inorganic core. It has been found that the dispersibility of palygorskite particles in organic solvents is significantly improved by grafting polymers onto the surface of palygorskite particles. The polymer-grafted palygorskite nanoparticles possess excellent decoloration capacity in organic solvents.     

相对平坦模的$\aleph$-积

设$M$是右$R$-模, $\aleph$是一个无穷基数. 称右$R$-模$N$是$\aleph$-$M$-凝聚的,如果对任意的$B/A\hookrightarrow mR$,其中设$M$是右$R$-模, $\aleph$是一个无穷基数. 称右$R$-模$N$是$\aleph$-$M$-凝聚的,如果对任意的$B/A\hookrightarrow mR$,其中设$M$是右$R$-模, $\aleph$是一个无穷基数. 称右$R$-模$N$是$\aleph$-$M$-凝聚的,如果对任意的$B/A\hookrightarrow mR$,其中设$M$是右$R$-模, $\aleph$是一个无穷基数. 称右$R$-模$N$是$\aleph$-$M$-凝聚的,如果对任意的$B/A\hookrightarrow mR$,其中$0\leq A相似文献   

Optimal control for a population dynamics with age-dependent and diffusion in a periodic environment

Here we consider the optimal harvesting problem for a periodic age-dependent population dynamics with diffusion. Namely, we investigate the model with periodic vital rates and a periodic forcing term that sustains oscillations. By using Mazur’s theorem, we demonstrate existence of solutions of the optimal control problem and by the conception of normal cone, we also obtain the first order necessary conditions of optimality for the problem. Our results extend some known criteria.