Sustainable Route for Synthesizing Aluminosilicate EU-1 Zeolite

Developing sustainable routes for the synthesis of zeolites is still a vital and challenging task in zeolite scientific community. One of the typical examples is sustainable synthesis of aluminosilicate EU-1 zeolite, which is not very efficient and environmental-unfriendly under hydrothermal condition due to the use of a large amount of water as solvent. Herein, we report a sustainable synthesis route for aluminosilicate EU-1 zeolite without the use of solvent for the first time. The physicochemical properties of the obtained EU-1 zeolite are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), N₂ sorption, inductively coupled plasma (ICP) analysis, and solid nuclear magnetic resonance (NMR), which show the product has high crystallinity, uniform morphology, large BET surface area, and four-coordinated aluminum species. Moreover, the impact of synthesis conditions is investigated in detail. The sustainable synthesis of aluminosilicate EU-1 zeolite under solvent-free     

Enhanced photovoltaic properties of polymer-fullerene bulk heterojunction solar cells by thermal annealing

The effect of a thermal annealing treatment on the performance of bulk heterojunction photovoltaic cells based on poly[2-methoxy-5-(2′-ethyl-hexyloxy)-p-phenylene vinylene] (MEH-PPV) and fullerene (C₆₀) composites is investigated. Upon thermal annealing at 120 ^°C, short-circuit current and power conversion efficiency (η) are more than tripled, while a sharp rise by eight times in and η is found for the device annealed at 200 ^°C. It is concluded that the improved phase separation between MEH-PPV and C₆₀ leads to the enhancement of and η at 120 ^°C, while thermodynamic molecule arrangement at the higher temperature of ∼200 ^°C induces a significant increase in all photovoltaic parameters of composite devices except the open-circuit voltage .     

Robust anti-synchronization of a class of delayed chaotic neural networks

This paper deals with the anti-synchronization problem of a class of delayed neural networks. Based on the Lyapunov stability theory and the Halanay inequality lemma, a kind of controller is designed. It is proved that this kind of controller can achieve anti-synchronization of neural networks with delays. Numerical simulations demonstrate the effectiveness and robustness of the proposed anti-synchronization scheme.     

Direct immobilization of iodine-loaded silver-coated silica gel with silicate glass powders at low temperature

Journal of Radioanalytical and Nuclear Chemistry - To long-term immobilization of secondary iodine-waste, iodine loaded silver-coated silica-gel (AgIs), glass-powder was used to directly solidify...     

基于氮杂Mn咔咯二维纳米材料的单原子Mn中心催化氧化烷烃制醇

咔咯是由四个吡咯共轭相连而形成的具有芳香性的新型卟啉类大环化合物,但咔咯分子中存在一个直接连结两个吡咯环的C?C键,与卟啉相比,仅仅是少了一个“meso”位置的C原子.因此,在结构上,咔咯含有三个“吡咯型”氮原子和一个“吡啶型”氮原子,当咔咯失去三个内氢原子后变成了三价阴离子,易与金属形成高价态的稳定配合物.氮杂咔咯是一种咔咯的meso位上的C被取代为N的咔咯衍生物.与正常的咔咯相比,它更易于与过渡金属形成稳定配合物.正是由于这些独特的结构特点,使其在金属催化、染料敏化太阳能电池、光敏剂、金属传感器、甚至在医学上都有很好的应用前景.金属有机大环均相催化剂的非均相化,是改进反应产物分离和实现催化剂循环使用的最简单有效方法之一.环境友好的Mn氮杂咔咯催化剂,在温和条件下可以利用氧气直接将有机底物氧化.本文选用Mn氮杂咔咯催化剂作为基本构建单元,通过理论计算,构建了一种新型的具有高催化活性的含Mn氮杂咔咯环结构单元的二维纳米催化材料.我们分别使用高斯软件(Gaussian 09)和维也纳从头算模拟软件包(VASP)对孤立分子和周期性体系进行结构优化以及性质的计算.在这种二维材料中,每一个Mn原子作为相对独立的金属单原子中心(SAC),保留了单环中Mn金属中心的高催化活性.在温和的光照条件下,Mn金属中心可以直接活化氧气生成类自由基[Mn]-O-O中心,随后[Mn]-O-O中心可以有效地通过夺取有机底物中的H和紧接着新生自由基的偶合反应,选择性氧化C?H键为C?OH键.另外,通过沿[Mn]-O-O反应轴施加不同强度的外电场,可对此二维纳米材料的催化反应活性进行精细调控.本文为实验上制备基于Mn氮杂咔咯的非均相催化剂以及单原子Mn基催化剂提供了理论依据.     

Cu/MoS2的熔盐电解法制备及其在碱性条件下析氢反应性能的提高

通过熔盐电解法并掺杂过渡金属Cu制备2种不同纳米结构的Cu/MoS_2。采用涂敷法制备工作电极,通过X射线衍射(XRD)、透射电子显微镜(TEM)、能量散射X射线谱(EDS)、扫描电子显微镜(SEM)、选区电子衍射(SAED)以及各种电化学手段验证了其结构和性能。结果表明,纳米片状Cu/MoS_2在碱性溶液(1 mol·L~(-1)KOH)中表现出优异的析氢催化性能:在电流密度为10 mA·cm~(-2)时过电位为199.6 mV,Tafel斜率为59 mV·dec~(-1),双电层电容为26.1 mF·cm~(-2),等效电荷转移电阻为12.4Ω,具有较为良好的电化学耐久性和稳定性。     

某型雷达高频舱数字电路测试系统的设计

某型引进装备雷达高频舱部位数字电路随着使用年限的增长,使用频率的增多,故障率逐年增高,已严重制约装备功能的发挥;针对原有备件必须在所属装备测试的验证方式,对装备本身消耗大、验证手段单一,无法满足维修保障需求的问题,开发了基于实物数据采集、分析、测试于一体的自动测试系统,有效地解决了装备作为唯一验证手段的现状,同时大大提高了测试验证的工作效率及验证的准确性,对装备整体功能以及局部功能的检测产生很大的作用,实用性强,适于推广应用。     

微通道换热器复合翅片的传热特性研究

研究了管径对微通道换热器传热性能的影响,并在百叶窗翅片的基础上开发了两种复合翅片。计算结果表明:在同一迎面风速下,1mm管径的百叶窗翅片Nu数分别比1.5mm和1.8mm管径的大4.8%~10.5%和24.6%~25.8%。JF值增加11%~15%和26%~28%,说明管径为1mm时微通道换热器的综合性能更好。与百叶窗翅片相比,百叶窗-三角翼复合翅片的换热系数减小1.9%~5.4%,但压降降低7.8%~12.7%,表明复合翅片是一种高效低阻翅片。     

Theoretical studies of cobalt(I)‐catalyzed hydroacylation of vinylsilanes and alkyl aldehydes

Density functional theory (DFT) was used to investigate computationally cobalt(I)‐catalyzed hydroacylation of vinylsilanes and alkyl aldehydes to give ketones. Calculation indicated that cobalt(I)‐catalyzed hydroacylation had eight possible reaction pathways. In the cobalt‐hydride complexes IM2a and IM2b, the hydrogen migration occurred prior to the carbon–carbon bond‐forming reaction. In the complexes IM3a1 and IM3b1, the carbonyl elimination reaction occurred prior to the direct reductive elimination reaction. In the cobalt–carbonyl complexes IM4a and IM4b, the carbonyl insertion reaction was much easier to achieve than the decarbonylation reaction. The dominant reaction pathway was the reaction channel IM1a → TS1a → IM2a → TS2a1 → IM3a1 → TS4a → IM4a → TS5a → IM5a → TS6a → IM6a, and the reductive elimination reaction was the rate‐determining step for this channel, so the dominant product predicted theoretically was the linear ketone. Furthermore, the solvation effect was remarkable, and it decreased generally the free energies of the species. Copyright © 2015 John Wiley & Sons, Ltd.     

Syntheses and Crystal Structures of Two New Pentaborates Templated by Transition-Metal Complexes

Two new pentaborates [M(dap)₃][B₅O₆(OH)₄]₂·H₂O (M = Co (1) and Ni (2); dap = 1,2-diaminopropane) have been hydrothermally synthesized. Both structures were determined by single crystal X-ray diffraction and further characterized by elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence spectroscopy. Two compounds are isostructural and consist of isolated pentaborate [B₅O₆(OH)₄]^? anions and [M(dap)₃]²⁺ complex cations. The anionic [B₅O₆(OH)₄]^? groups are linked by extensive hydrogen bonds to form a 3-D supramolecular framework with large channels, in which the transition-metal complex templates are located. The luminescent properties of 1 and 2 were studied, and blue luminescence occurs with an emission maximum at 405 and 408 nm upon excitation at 332 and 328 nm respectively. Crystal data: 1, monoclinic, space group P2₁/c (No. 14), a = 9.7159(5) Å, b = 29.3372(19) Å, c = 11.5121(6) Å, β = 103.286(5)°, V = 3193.6(3) ų, Z = 4; 2, monoclinic, space group P2₁/c, a = 9.7264(4) Å, b = 29.3810(16) Å, c = 11.5185(6) Å, β = 103.249(4)°, V = 3204.0(3) ų, Z = 4.