电化学法制备铜基超疏水结构及其耐蚀性能研究

目的改善铜在海洋环境中的耐腐蚀性能。方法将化学刻蚀与电化学氧化成膜相结合,在金属铜表面制备超疏水结构,采用单因素实验分别考察了硬脂酸浓度、苯并三氮唑浓度、电沉积电压以及电沉积时间对所制备表面结构接触角的影响规律,通过动电位极化曲线和电化学阻抗谱研究了铜基超疏水结构在3.5%NaCl溶液中的耐蚀性能。结果当硬脂酸浓度为0.02 mol/L,苯并三氮唑质量浓度为40 mg/L,电沉积电压为8 V,腐蚀时间为12 h时,所制备的铜基超疏水膜接触角达到了158°,滚动角为3°。动电位极化测试表明,超疏水表面同时抑制了阳极和阴极反应,经超疏水处理的铜在3.5%NaCl溶液中的自腐蚀电流密度相比未经处理时减小了约2个数量级,缓蚀效率高达99%。电化学阻抗结果表明,电荷转移电阻由1.61 kΩ·cm~2增大至41.3 kΩ·cm~2,铜基超疏水膜具有优异的耐蚀性能。结论通过化学刻蚀与电化学氧化成膜可在铜表面构筑超疏水结构,使其在海洋环境下具有优异的耐蚀性能。     

W-Grid: A scalable and efficient self-organizing infrastructure for multi-dimensional data management,querying and routing in wireless data-centric sensor networks

Data-centric sensor networks are advanced ad hoc networks that act like a distributed database managing and indexing sensed data in order to efficiently perform advanced in-network tasks, such as routings, searches, data processing, fusion and analysis. The supplied distributed services, such as routing, content location and information sharing should be provided anywhere and at any time optimizing energy consumptions, computational resources, memory occupation and radio transmissions. Moreover, the network traffic should be equally balanced among participants in order to avoid premature discharge of some devices that may partition the network. This work describes a fully decentralized infrastructure able to self-organize nodes in ad hoc networks by exploiting local interactions and topology learning among devices. In this solution all nodes are peers and nothing prevent the approach to be used in wireless mesh networks as well. Differently from existing solutions, our proposal does not require global information or external help, such as the Global Positioning System, which works only outdoor with a precision and an efficacy both limited by weather conditions and obstacles. The infrastructure natively enables devices to perform routing and data management without using message broadcast/flooding operations. The work introduces also a feature, called full learning, that improves routing performances while balancing the traffic among devices. We report an extensive number of simulations comparing the new solution results with four existing proposals, two of which deriving from preceding versions of the infrastructure.     

不同侧链BPPO阴离子交换膜的制备及其抗污染性能

采用含有不同碳链长度的4-乙基吡啶、3-丁基吡啶与3-己基吡啶,通过亲核取代反应分别对溴化聚苯醚（BPPO）进行季铵化,制得三种阴离子交换膜（QBPPO-1、QBPPO-2、QBPPO-3）并对其电化学性能、脱盐性能以及抗污染性能进行了研究。实验结果表明随着吡啶环上烷基碳链的增长,制得的离子交换膜的离子交换容量呈现下降趋势,由1.92 mmol/g降至1.34 mmol/g,而膜面电阻逐渐增加,由2.99 Ω·cm²增加到10.59 Ω·cm²;在电渗析实验中,与商业日本Fuji阴离子交换膜相比,本实验制备的三种离子交换膜均呈现出较高的脱盐率;在污染实验中,随着高分子骨架侧链碳链的增长,离子交换膜在污染实验中的的转折时间逐渐变短,抗污染能力下降;计算模拟结果表明疏水作用在有机污染物（十二烷基苯磺酸钠）与离子交换膜内高分子骨架侧链的亲和相互作用中占有重要地位。     

Localized corrosion in an electrical submergible pump (ESP)

A failure analysis was performed on bolts (Monel K-500) that serve to support and join critical components of an electrical submergible pump (ESP) located in a saline solution environment. Based on the experimental results, it can be concluded that pitting corrosion was the primary cause of failure. All fracture surfaces displayed an initial zone of intergranular fracture promoted by pitting corrosion and a propagation zone with transgranular fracture due to mechanical load. High concentrations of sulfur (S) and chlorine (Cl) were found on two corrosion product layers covering the bolt surface, revealing that an aggressive electrochemical reaction occurred in the stagnant environment. Under these layers, small pits of 10–30 μm in depth were observed that initiated the cracking paths that eventually became complete fractures.     

PEI交联的PECH/nylon复合阴离子交换膜的制备及性能研究

聚环氧氯丙烷（PECH）是一种线性高分子聚合物,具有较好的稳定性和成膜性能,且以PECH为基体制备阴离子交换膜,可避免致癌物质如氯甲醚、双氯甲醚的使用,但存在机械强度差与吸水性较大等缺点。本研究采用聚乙烯亚胺（PEI）作为交联剂,通过其与PECH发生交联反应,在其内部形成网状结构限制PECH膜在水中的过度溶胀,从而增强膜的机械强度,同时引入尼龙网布（nylon）作为支撑材料进一步提高膜的力学性能,制备了QCPECH/nylon复合阴离子交换膜。研究结果表明,制备的P1膜在电渗析应用过程中的脱盐效率（94.8%）比商业膜（Neosepta AMX）的脱盐效率（92.4%）更高,由此可见,用PEI交联的PECH/nylon复合阴离子交换膜在电渗析脱盐中具有潜在的发展前景。     

Solvent-induced supramolecular isomers: Two dimensional coordination polymers constructed by Cu(II) and fluconazole

Two Cu(II)–fluconazole supramolecular isomers 1 and 2 formulated as (flu)₂Cu(SCN)₂ (flu = fluconazole) have been synthesized and structurally characterized by single crystal X-ray diffraction. Different solvent media lead to the different binding modes of anion SCN⁻ and the flexible C–C chain of fluconazole has been rotated in the two isomers. Complex 1 exhibits a two dimensional square grid-like layer and complex 2 exhibits a two dimensional framework with a parquet motif. Different H-bonds and stacking modes are observed in the two isomers. Complex 1 is nonemissive, whereas complex 2 exhibits photoluminescence property.     

Development of Venturi negative-pressure secondary dedust device and application of local spray closure technique

In order to enhance the spray for dust suppression performance in a fully-mechanized mining face, based on orthogonal test, comparison test, numerical simulation and field application, the Venturi negative-pressure secondary dedust device was developed. Meanwhile, the local spray closure technique was proposed, which can not only effectively prevent the escape of coal dust from entering the footway space, but also remove coal dust around the respiratory zone from the footway space successfully. The results demonstrated that, under spray pressure of 6?MPa, the Sauter mean droplet size, negative pressure suction flow rate and effective spray distance of the novel dedust device with a throat-to-nozzle distance and throat diameter of 20?mm and 65?mm were 47.37?µm, 11.21?m³/min and 5.4?m respectively. Moreover, the novel dedust device produced droplets to a smaller scale than a single-nozzle. Additionally, the negative pressure and airflow velocity in the negative pressure suction inlet of novel dedust device were within the range from ?0.97?Pa to ?541.04?Pa and from 2.96?m/s to 27.29?m/s respectively. Finally, compared with the original dust suppression measures, the local spray closure technique can enhance the removal ratio of respiratory dust by an average of 44.3%.     

4,4'-二叠氮二苯乙烯-2,2-二磺酸钠的应用及发展前景

4,4'-二叠氮二苯乙烯-2,2-二磺酸钠（DAS）是一种带有磺酸基团的芳香类双叠氮化合物。分子中的叠氮基既可在Cu(Ⅰ)催化的点击化学反应体系中与端炔基形成三唑结构，也能在紫外辐射条件下于两端生成高活性氮宾自由基并插入聚合物链段。本文简单介绍了DAS参与的点击化学反应，简述了DAS的光化学交联原理及其相较于其他化学交联剂的优点，重点论述了近些年DAS在光刻、电池隔膜、分子印迹、医用材料、药物缓释和离子交换膜等领域相关的研究应用及发展前景。此外，提出将DAS与石墨烯、金属有机框架材料（MOF）、聚电解质及脂肪族聚合物等结合应用；设计与DAS结构相似的新型叠氮类分子；深入地探究光化学反应机理；实现叠氮基团的选择性插入等是未来研究的重要趋势。     

VIBE: An energy efficient routing protocol for dense and mobile sensor networks

We present a new protocol that manages wireless sensor networks in several scenarios including large scale, high density and high mobility deployments. An example of one of the main applications is to communicate important information from inaccessible areas by spreading “enough” mobile sensors which must self-configure and assemble. According to our protocol, virtual infrastructure-based energy-efficient (VIBE) routing, the information is routed in a multihop, cluster level fashion by enabling each sensor to make individual decisions regarding its mode of operation. The aim is to prolong the network's lifetime by minimising the average energy spent for each communication. VIBE is capable of addressing mobility requirements as it is completely independent of any kind of topological knowledge and control messages. We show by extended experiments that VIBE performs very well in terms of consumed energy by comparing it to standard directed flooding and greedy forwarding protocols. We also compare it to LEACH (Rabiner Heinzelman et al., 2000) and a more recent protocol, namely MECH (Chang and Kuo, 2006). VIBE proves to save large amounts of energy when compared to the first three and up to 15% compared to MECH.