摘要：With the strict control of sulfur content in fuels,oxidative desulfurization(ODS),a promising desulphurization technology,needs to be continuously *** this study,we integrated multiple approaches(fabricating a porous structure,increasing phosphomolybdic acid(PMo)loading,improving amphiphilicity,and enhancing the intrinsic activity of PMo using a reductive framework)into PAF-54 carriers to improve ODS catalytic *** catalytic performance suggested that PAF-54 was not simply used as a carrier for PMo by physical *** the binding process,electron transfer between PAF-54 and PMo formed Mo^(5+)with superior catalytic *** to the presence of PAF-54,the catalytic activity of PMo as the active component qualitatively improved to achieve rapid and efficient *** importantly,we found that other nitrogen-rich porous organic polymers can also reduce some of Mo^(6+)in PMo during loading,and its formation mechanism was *** work provides a feasible strategy for designing highly efficient DOS catalysts.

摘要：由可见光驱动的将CO_(2)转化为高附加值燃料是一种清洁可再生的技术,有助于控制全球变暖和应对能源短缺.近年来,二维的金属偶氮盐框架(2D MAFs)因其特定的电子传输路径、高度暴露的表面活性位点及可调节的吸光能力,在CO_(2)光还原研究中备受关注.然而,对其在该领域的研究仍处于初级阶段.本文设计了一种新型二维MAFs(compound 1),通过四-(4-四唑基苯基)乙烯(H;4;TTPE)与钴的自组装实现了对CO_(2)的光还原.作为对比,通过类似的合成过程构建了具有三维结构的compound 2.非均相光催化实验结果显示,2D compound 1的光还原性能明显优于3D compound 2,在相同条件下,其CO产率高达11.56 mmol g^(-1)h^(-1),是compound 2(1.94 mmol g^(-1)h^(-1))的6倍.这一性能优势源于compound 1独特的二维结构,其不仅具有有利于CO_(2)还原的能级,还能在整个CO_(2)光还原过程中促进电子-空穴高效分离.本工作为设计适用于高效CO_(2)光还原的2D MAFs光催化剂指引了方向.

摘要：Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this study, a novel TiN/C3N4/CdS nanotube arrays core/shell structure is designed to improve the photoelectrochemical catalytic performance of the g-C3N4-based heterojunctions. Among them, TiN nanotube arrays do not respond to simulated solar light, and thus only serve as an excellently conductive nanotube arrays backbone for supporting g-C3N4/CdS heterojunctions. g-C3N4 prepared by simple liquid atomic layer deposition, which possesses appropriate energy band position, mainly acts as the electron acceptor to transport and separate electrons. Deposited CdS quantum dots obtained by successive ionic layer adsorption reaction can effectively absorb visible light and thus act as a light absorber. The TiN/C3N4/CdS nanotube arrays core/shell structure could be verified by X-ray diffractions, Raman spectra, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy elemental mappings and X-ray photoelectron spectroscopy. Compared with TiN/C3N4 nanotube arrays, the TiN/C3N4/CdS samples greatly improve the photoelectrochemical performance, which can be evaluated by photoelectrochemical tests and photoelectrochemical catalytic degradation. Especially, the optimized photocurrent density of TiN/C3N4/CdS has almost 120 times improvement on TiN/C3N4 at 0 V bias under simulated sunlight, which can be ascribed to the effective expansion of the light absorption range and separation of electron-hole pairs.

摘要：An integrated implementation framework of an intelligent recommendation system for outdoor video advertising is proposed, which is based on the analysis of audiences＇ characteristics. Firstly, the images of the scene and the people who view the video advertisements are captured by the net- work camera deployed on the video advertising terminal side. Then audiences＇ characteristics can be obtained by applying computer vision technologies ： face detection, face tracking, gender recogni- tion and age estimation. Finally, an intelligent recommendation algorithm is designed to decide the most fitting video ads for each terminal according to multi-dimensional statistical information of its reover, a novel face detection method and a new face tracking method have been proposed to meet the practical requirements of the system, of which the average Fl-score is O. 988 and 0. 951 respec- tively.

摘要：Covalent organic frameworks （COFs）, established as an emerging class of crystalline porous polymers with high surface area, structural diversity, and esignability, attract much interest and exhibit potential applications in catalysis. In this review, we summarize the use of COFs as a versatile platform to develop heterogeneous catalysts for a variety of chemical reactions. Catalytic COFs are categorized in accordance with the types of active sites, involving single functional active sites, bifunctional active sites, and metal nanoparticles （NPs） embedded in pores. Special emphasis is placed on the deliberate or incidental synthesis strategies, the stability, the heterogeneity, and the shape/size selectivity for COF catalysis. Moreover, a description of the application of COFs as photocatalysts and electrocatalysts is presented. Finally, the prospects of COFs in catalysis and remaining issues in this field are indicated.

摘要：A field experiment was carried out from 2003 to 2013 in the Wanzhong Farm of the Hainan Island, China, to determine the effects of two long-term banana rotations on the abundance and trophic groups of soil nematode communities in the island. The experiment was set out as a randomized complete block design with three replications of three treatments： banana-pineapple rotation （AB）, banana-papaya rotation （BB） and banana monoculture （CK） in a conventional tillage system. Soil samples were taken at depths of 0-10, 10-20 and 20-30 cm, and nematodes were extracted by a modified cotton-wool filter method and identified to the genus level. Nematode ecological indices of Shannon-Weaver diversity （Ht）, dominance index （A）, maturity index （MI）, plant parasite index （PPI）, structure index （SI）, enrichment index （EI）, and channel index （CI） were calculated. A total of 28 nematode genera with relative abundance over 0.1% were identified, among which Tylenchus and Paratylenchus in the AB, Thonus in the BB, Tylenchus and Helicotylenchus in the CK were the dominant genera. The rotation soils favored bacterivores, fungivores and omnivores-predators with high colonizer-persister （c-p） values. Soil food web in the rotation systems was highly structured, mature and enriched as indicated by SI, MI and EI values, respectively. Higher abundance of bacterivores and lower values of CI suggested that the soil food web was dominated by a bacterial decomposition pathway in rotation soils. Nematode diversity was much higher after a decade of rotation. Soil depth had significant effects on the abundance of soil nematodes, but only on two nematode ecological indices （λ and MI）.

摘要：An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The surfaces of graphene are densely covered by Fe3O4 or Ni nanoparticles with a narrow size distribution, and the magnetic nanoparticles are well distributed on each graphene sheet without significant conglomeration or large vacancies. The coated graphene materials exhibit remarkably improved electromagnetic （EM） absorption properties compared to the pristine graphene. The optimal reflection loss （RL） reaches -46.4 dB at 15.6 GHz with a thickness of only 1.4 mm for the Fe3O4/graphene composites obtained by applying 100 cycles of Fe2O3 deposition followed by a hydrogen reduction. The enhanced absorption ability arises from the effective impedance matching, multiple interfacial polarization and increased magnetic loss from the added magnetic constituents. Moreover, compared with other recently reported materials, the composites have a lower filling ratio and smaller coating thickness resulting in significantly increased EM absorption properties. This demonstrates that nanoscale surface modification of magnetic particles on graphene by ALD is a very promising way to design lightweight and high-efficiency microwave absorbers.

摘要：As an emerging class of crystalline porous materials, covalent organic frameworks（COFs） have been widely used as catalysts or catalyst supports. Flexible regulation of the pores and easy introduction of functional active sites onto the skeleton of COFs make them promising platforms for many catalysis applications. However, only a single function is generally observed in these COFs. Herein, we synthesized a negatively charged ionic COF（I-COF） and successfully incorporated functionalized counter ions, that is, metallic Mn2＋ and a coordination complex of manganese（Ⅱ） bipyridine complexes（[Mn（bpy）2]2＋）, via a simple ion exchange process. The resulting I-COFs can act as effective heterogeneous catalysts for epoxidation reactions. We envisage that with this type of ionic architecture, a variety of other functional cations could be exchanged into the frameworks, thus making the COF a versatile platform for different applications.

摘要：Covalent organic frameworks(COFs),with two dimensional(2D-)or three dimensional(3D-)structures,have accessible open channels or nanopores,with uniform sizes ranging from angstroms to nanometers and have emerged as an excellent and promising platform for designing catalysts or catalyst ***,a 2 D-COF grafted with a 1-alkyl-3-methylimidazolium-based ionic liquid(AMIMBr@H2 P-DHPh COF)on the channel walls was synthesized and utilized as a highly efficient heterogeneous catalyst for the chemical fixation of CO2 via a reaction with epoxides under solvent-free and co-catalyst-free *** as-synthesized AMIMBr@H2 P-DHPh COF shows excellent catalytic activity in promoting the cycloaddition reactions between epoxide and CO2;the excellent catalytic activity was maintained for up to five *** like high porosity,functional versatility,easy modification of COFs,and high catalytic activity of ionic liquids,have been realized in a single material.

摘要：Sluggish water dissociation kinetics severely limits the rate of alkaline electrocatalytic hydrogen evolution reaction(HER).Therefore,finding highly active electrocatalysts and clarifying the mechanism of water dissociation are challenging but *** this study,we report an integrated nanoporous nickel(np-Ni)catalyst with high alkaline HER performance and the origin of the corresponding enhanced catalytic *** 1 mol L^(-1) KOH solution,this np-Ni electrode shows an HER overpotential of 20 mV at 10 mA cm^(-2),along with fast water dissociation *** excellent performance is not only attributed to the large surface area provided by the three-dimensional interconnected conductive network but also from the enhanced intrinsic activity induced by the unique surface *** studies reveal that the types of oxygen species that naturally form on the Ni surface play a key role in water ***,when the lattice oxygen almost disappears,the Ni surface terminates with_(ads)orbed oxygen(O_(ads)),exhibiting the fastest water dissociation *** functional theory calculation suggests that when O_(ads)acts as the surface termination of Ni metal,the orientation and configuration of polar water molecules are strongly affected by O_(ads).Finally,the H–OH bond of interfacial water molecules is effectively activated in a manner similar to hydrogen *** work not only identifies a high-performance and low-cost electrocatalyst but also provides new insights into the chemical processes underlying water dissociation,thus benefiting the rational design of electrocatalysts.