In situ prepared polypyrrole for low humidity QCM sensor and related theoretical calculation

In situ preparation of polypyrrole (Ppy) by photo-polymerization coated on a quartz crystal microbalance (QCM) as a low humidity sensor was reported. Different concentrations of Ppy films say 0 wt.% (as blank), 0.1, 1, and 10 wt.% were investigated to measure humidity concentrations between 14.7 and 5412.5 ppm_v. The adsorption/desorption behavior was also examined at humidity concentration 510.2 ppm_v. The sensitivities of 0, 0.1 and 1 wt.% Ppy films at 51.5 ppm_v were 0.143, 0.219 and 0.427, respectively. For 1 wt.% Ppy, the highest sensitivity was obtained. The slope and correlation coefficients (R²) for 1 wt.% Ppy at the ranges of 14.7–898.6 ppm_v were 0.0646 and 0.9909, respectively. A series of molecular simulations have been carried out to calculate bond energy for the water molecule interaction with Ppy, which was found to be 3 kcal/mol indicating the existence of hydrogen bonding during the sorption process. Based on Langmuir isotherm adsorption assumption, for 0.1 and 1 wt.% Ppy films, the association constants were 2606.30 and 5792.98, respectively. This larger association constant for 1 wt.% Ppy film explains higher sensitivity.     

一种有效吸附Pb(Ⅱ)的Zr基金属有机凝胶的合成

以合成的 4,4,4-三甲酸三苯胺(H₃TCA)为主配体,通过溶剂热法合成了一种超分子无定型的锆基金属有机凝胶(Zr-MOG)。并通过一种简单的恒定时间控制晶化方法,使UIO-66(即Zr-MOF)凝胶化合成非晶态的Zr-MOG。结果表明,所制备的Zr-MOG拥有凝胶软材料的多层结构和非晶聚合物网络,对Pb(Ⅱ)具有良好的吸附能力。此外,以冰醋酸为晶化促进剂,成功地实现了晶态MOF和高分散非晶态MOG的转化。     

用于锂离子电池的凝胶聚合物电解质的制备与性能

以丙烯腈(AN)、丙烯酸甲酯(MA)和衣康酸锂(IALi)为自由基共聚反应的主要单体, 采用溶液聚合方法, 合成轻度交联的P(AN-MA-IALi)聚合物电解质膜.通过FTIR, DSC和SEM等测试方法对共聚物的结构进行了表征, 利用交流阻抗等电化学方法对该膜的导电性能进行了研究.实验结果表明, 所制备的交联聚合物的室温电导率达到10-5~10-4 S/cm, 当IALi的质量分数为3%时, 所制备的聚合物电解质膜的电导率最大可达到1.89×10-4 S/cm.     

Synchronization of coupled metronomes on two layers

Coupled metronomes serve as a paradigmatic model for exploring the collective behaviors of complex dynamical systems, as well as a classical setup for classroom demonstrations of synchronization phenomena. Whereas previous studies of metronome synchronization have been concentrating on symmetric coupling schemes, here we consider the asymmetric case by adopting the scheme of layered metronomes. Specifically, we place two metronomes on each layer, and couple two layers by placing one on top of the other. By varying the initial conditions of the metronomes and adjusting the friction between the two layers, a variety of synchronous patterns are observed in experiment, including the splay synchronization (SS) state, the generalized splay synchronization (GSS) state, the anti-phase synchronization (APS) state, the in-phase delay synchronization (IPDS) state, and the in-phase synchronization (IPS) state. In particular, the IPDS state, in which the metronomes on each layer are synchronized in phase but are of a constant phase delay to metronomes on the other layer, is observed for the first time. In addition, a new technique based on audio signals is proposed for pattern detection, which is more convenient and easier to apply than the existing acquisition techniques. Furthermore, a theoretical model is developed to explain the experimental observations, and is employed to explore the dynamical properties of the patterns, including the basin distributions and the pattern transitions. Our study sheds new lights on the collective behaviors of coupled metronomes, and the developed setup can be used in the classroom for demonstration purposes.     

一种有效吸附Pb（Ⅱ）的Zr基金属有机凝胶的合成

以合成的4,4,4-三甲酸三苯胺(H₃TCA)为主配体,通过溶剂热法合成了一种超分子无定型的锆基金属有机凝胶(Zr-MOG)。并通过一种简单的恒定时间控制晶化方法,使UIO-66(即Zr-MOF)凝胶化合成非晶态的Zr-MOG。结果表明,所制备的Zr-MOG拥有凝胶软材料的多层结构和非晶聚合物网络,对Pb(Ⅱ)具有良好的吸附能力。此外,以冰醋酸为晶化促进剂,成功地实现了晶态MOF和高分散非晶态MOG的转化。     

鱼中铅、镉、汞和砷的测定

采用二种消化方法并用原子吸收分光光度法和原子荧光光谱法测定了鱼肉和鱼肝中铅、镉、汞、砷的含量。改进了国标每种元素需要一种方法测定的不足。结果表明在污染的河水中鱼肉的重金属元素含量比河水中的高,在同一条鱼中鱼肝中的重金属元素含量比鱼肉中的高。测定值与国标测定值以及标准物质推荐值一致。该方法快速、简便、准确。     

Cover Picture

The cover picture shows how protein matrices can regulate the spatial arrangement and orientation of a heme-based donor (Zn-heme: ZnPP)-sensitizer (Ru²⁺(bpy)₃)-acceptor (cyclic viologen: BXV⁴⁺) triad. A U-shape conformation of the triad without protein matrix changes into a triangle arrangement by incorporation into apocytochrome b₅₆₂ (Cyt-b₅₆₂), or into a further extended conformation by apomyoglobin (Mb) matrix. The electron transfer pathways and the lifetimes of the photoinduced charge-separated states were remarkably affected by the protein wrapping effect.     

Cluster synchronization in complex network of coupled chaotic circuits: An experimental study

By a small-size complex network of coupled chaotic Hindmarsh-Rose circuits, we study experimentally the stability of network synchronization to the removal of shortcut links. It is shown that the removal of a single shortcut link may destroy either completely or partially the network synchronization. Interestingly, when the network is partially desynchronized, it is found that the oscillators can be organized into different groups, with oscillators within each group being highly synchronized but are not for oscillators from different groups, showing the intriguing phenomenon of cluster synchronization. The experimental results are analyzed by the method of eigenvalue analysis, which implies that the formation of cluster synchronization is crucially dependent on the network symmetries. Our study demonstrates the observability of cluster synchronization in realistic systems, and indicates the feasibility of controlling network synchronization by adjusting network topology.     

New Quantum Private Comparison Protocol Using χ-Type State

We present a new quantum private comparison protocol based on the four-particle χ-type states. Different from previous protocols using the four-particle χ-type states, our protocol have some advantages. Without using the entangled character, we only need to prepare one type of χ-type state and N χ-type states. And we use the Pauli local unitary operation on particles to encode the information and to extract information by measurement. We also discuss that our protocol can withstand all various kinds of outside attacks and participant attacks.     

Viscoelastic measurement of complex fluids using forced oscillating torsion resonator with continuously varying frequency capability

Traditional torsional resonators, often obtaining the viscoelastic moduli of complex fluids only at one or several given discrete frequencies, lack the continuously varying frequency capability. This is an obvious disadvantage of the traditional torsional resonator technique. This paper presents an improved strategy, based on our previous discrete-frequency-measuring method (Wang et al., J Rheol 52:999–1011, 2008), to overcome such restriction and thus accomplish the continuously varying frequency capability of the traditional torsional resonator for measuring the viscoelastic properties of complex fluids. The feasibility of this strategy is demonstrated with the Newtonian fluids (several water–glycerol solutions) of viscosities varying from 10 to 1,400 cp by using our homemade torsion resonator apparatus in the 10 ~ 2,500 rad/s frequency range (continuous frequencies). Some results for typical viscoelastic polymers (two polyethylene oxide (PEO) aqueous solutions) are also given. Additionally, a comparison of the PEO results is made with the common rheometer technique. It is demonstrated that this improved strategy could enable the traditional torsional resonators, with one oscillating resonance mode, to work as the microrheological technique and the common rheometer technique in the continuous frequency range.