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Fluid catalytic cracking (FCC) is an important process in petroleum processing. Effective monitoring of the status and quality of FCC is vital. Accurate description of the relationship between process and quality variables is the basis of quality-driven monitoring. Many process variables affect the quality of FCC; some of these effects are linear, and others are nonlinear. We propose a combination method from the perspective of linearity and nonlinearity to improve the monitoring performance of FCC quality. Partial least squares (PLS) is initially used to extract linear features, and its residual space is saved as the input of the deep feedforward neural network (DFNN). DFNN is then used to extract nonlinear features for the further decomposition of subspaces. The PLS-DFNN method accurately describes processes involving linearity and nonlinearity. We construct three monitoring statistics to characterize the types of faults. The proposed method proves its excellent effect on a numerical simulation data set. It effectively distinguishes the types of faults on the Tennessee Eastman process data set, and the fault detection rate is superior to other related methods. Finally, we apply this method to the actual FCC and verify the superiority of this combination. [ABSTRACT FROM AUTHOR]

[Display omitted] Air filtration systems have difficulty avoiding problems of leakage and breakage of the filter medium, which aggravates the emission of dust particles. In this study, a numerical calculation model is established to study the dust-laden air filtration performance of a filter medium with pin holes. The calculation model is verified using experiments and by comparing the values of the filtration resistance and efficiency. The results demonstrated that, with the existence of leakage, the filtration efficiency decreased with time, decreased with an increase in the leakage ratio, and increased first and then decreased with an improvement in the filter medium accuracy. An extremely high filter medium accuracy was not conducive to improve the filtration efficiency, but it obviously increased the filtration resistance. The larger the leakage ratio, Lr , the smaller the optimal filter accuracy, e F , opt , and the maximum filtration efficiency, e T , max. The functional relationships between e F , opt , e T , max and Lr , as well as Q T , were obtained. With an increase in the leakage ratio, the filtration resistance and its rising rate decreased. The system quality factor decreased with the increase of the leakage ratio and increased with the increase of the filter quality factor. [ABSTRACT FROM AUTHOR]

Ionic radius of interfacial molecular can affect the interface property and key electron transfer processes occurring at interface in polymer solar cells. To study the effects of different ionic radius of electron transfer layer on device performances, we introduce various stearate salts (Na + , K + and Cs + ) as electron transfer layer to fabricate polymer solar cells. Interestingly, it is found that the key device parameters such as V oc , J sc , fill factor and PCE of polymer solar cells present regular change with the ionic radius increasing. We systematically study the effects of different ionic radius of electron transfer layer on the various parameters of polymer solar cells and believe this regularity paves a way for further understanding and improving the performances of polymer solar cells. [ABSTRACT FROM AUTHOR]

Zinc oxide is an attractive material applied for electron-transporting interlayers of polymer solar cells. Some factors limited the efficiency and performance of the ZnO-based PSCs, such as the poor conductivity and the traps existing on ZnO film. Here, we introduce a novel approach to optimize the property of ZnO electron-transporting interlayers for the further improvement of device performance by doping bis (trifluoromethane)-sulfonimide lithium salt (Li-TFSI) in ZnO film. It is found that this way not only increased electrical conductivity and charge extraction ability of the electron-transporting interlayers but also reduced charge recombination occurred at interface that was very important for fill factor improvement. Therefore, an optimized power conversion efficiency (PCE) of 9.94% was achieved, which was observed with 13.2% enhancement (9.94% vs 8.78%) compared to that of pure ZnO-based ones. This indicates that doping Li-TFSI in ZnO film is a promising strategy to optimize the ZnO film and enhance the performance of regular polymer solar cells. [ABSTRACT FROM AUTHOR]

A facile and efficient approach to the synthesis of secondary thioamides from ketoximes via Beckmann rearrangement has been established, using phosphorus pentasulfide as a dehydrating and thiating agent. It is also efficient for the preparation of primary thiobenzamide from benzaldoxime. This approach features simple-operation, easy-control and good to excellent yields. [ABSTRACT FROM AUTHOR]

A novel domino cross dehydrogenative coupling of 2-aryl acetals with unmodified ketones has been developed, using DDQ as both the oxidant and reactant precursor. [ABSTRACT FROM AUTHOR]

Satellite networks provide complete connectivity and worldwide data transmission capability for constructing the Internet of Things. However, because of the varying Internet of Things traffic density, satellite networks may endure imbalanced traffic requirements and frequent link congestion. To effectively resolve these problems and optimally transmit Internet of Things data, a novel hybrid global-local load balancing routing scheme for Low Earth Orbit satellite networks is proposed in this article. Hybrid global-local load balancing routing scheme enables satellites to route Internet of Things traffic through global planning and local real-time adjustments in two steps. In hybrid global-local load balancing routing scheme, given the predictive nature of Internet of Things traffic distribution and Low Earth Orbit satellite networks, the inter-satellite traffic demand is decomposed into a predictable long-range baseline and unpredictable short-range fluctuations. A global strategy is employed first for preliminary global traffic allocation based on long-range baselines, and a local strategy is then employed for route adjustments based on short-range fluctuations. With the combination of global planning and local real-time adjustments, network traffic can eventually obtain a near-optimal allocation. Numerical simulations indicate that in contrast to single-strategy schemes, hybrid global-local load balancing routing scheme can more thoroughly eliminate congestion, and it performs better in measures such as packet loss rate, average queuing delay, traffic distribution, route oscillation, and communication overhead. [ABSTRACT FROM AUTHOR]

Doping impure atoms into host semiconductor nanocrystals is used to tune the properties and functions of semiconductor nanocrystals (NCs). Here, we demonstrate a solution method for preparing O doped ZnS (ZnS(O)) colloidal NCs. The as-prepared NCs have been proved to be consistent with the crystal structure of ZnS and Zn 3d-O 2p hydrization existed in the as-prepared NCs as certified by O k-edge X-ray absorption spectra (XAS). The average size was measured to be about 8.5 nm by Transmission Electron Microscope (TEM). The role of pyridines was to control the size and tune the surface property. By doping oxygen into ZnS lattice, the energy levels of as-prepared NCs were moved down, giving a better band alignment for photovoltaic application. When it was applied to modify ZnO interlayer and form ZnO/ZnS(O) bilayer in the polymer solar cells (PSCs), the optimal power conversion efficiency (PCE) of the device based on ZnO/ZnS(O) reached 8.85% (8.59 ± 0.49%), which increased by 10% compared to ZnO-only control device with the optimal PCE of 8.00% (7.46 ± 0.54%). The novel approach has been proved to be facile and scalable, paving the way for synthetizing O doped semiconductor nanocrystal. [ABSTRACT FROM AUTHOR]

A catalyst‐free strategy has been established for the synthesis of β‐oxo sulfones via visible light‐induced oxysulfonylation of alkenes with arylazo sulfones with dioxygen in air. The present photoinduced transformation proceeds smoothly at room temperature in the absence of an external photosensitizer, which not only provides a mild and efficient approach to various β‐oxo sulfones, but also opens a different reaction mode for the photochemical reaction of arylazo sulfones. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel colliding pulse-jet mode for filter cleaning is put forward and tested. • Cleaning intensity can be remarkably improved using an colliding pulse jet. • The trigger time difference between top and bottom pulse jets is analyzed. Abstract Pleated filter cartridges with high pleat ratios and large filter surface are found to have great instances of patchy cleaning. In order to improve the intensity and uniformity of filter cleaning, a novel colliding pulse-jet cleaning method was designed and tested in this study. An experimental pulse-jet cleaning dust collector (the filtration chamber is 1225 × 750 × 1000 mm (width × depth × height)) was built with two nozzles installed over the filter cartridge (ϕ 320 × ϕ 240 × 660 mm) and on the cartridge bottom. The nozzle outlet pressure, pulse jet performance (intensity and uniformity), and compressed air consumption were studied. The effect of the trigger time difference between the top and bottom pulse jets on the performance was researched. This study demonstrated that the non-time-differenced colliding pulse-jet mode increased the pulse-jet intensity obviously to 2.56 times compared with the top-jet-only mode with some more air consumption (about 1.85 times than that in top-jet-only mode), but the pulse-jet uniformity slightly worsened. The pulse-jet intensity could be enhanced remarkably to 5.49 times if the colliding pulse jet was controlled in the strategy of varying trigger time difference, with the uniformity also increased obviously. [ABSTRACT FROM AUTHOR]

Abstract Self-support silver nanofibers with excellent electrocatalytic performance for oxygen reduction reaction (ORR) are successfully fabricated through a hybrid method combining an electrospinning process with an electroplating technique. This nanofiber-based catalyst demonstrated superior long-term stability and an unusually high methanol-tolerant effect that its ORR activity was enhanced, instead of lessened in 3 M methanol. The impact of microstructure and crystal facet on ORR activity is examined through quantifying the performance of the catalysts by electrochemical measurements. Through tuning the synthesis parameters, the onset potential, half-wave potential, and peak potential of 1.041 V, 0.848 V, and 0.864 V are achieved for the silver nanofibers with thorny structure, even superior to those of commercial Pt/C catalyst. Such excellent performance is attributed to two major factors, the micro morphology, i.e. thorn-on-fiber structure, and the crystal facet. The special thorny structure leads to the accumulation of electrons on the tip to act as highly active sites and better confinement of the oxygen between thorns, while the high ratio of (110) facets on the tip favors high catalytic activity. This kind of low-cost silver nanofiber-based catalyst exhibits a highly beneficial prospect as a potential alternative catalyst for oxygen reduction reaction. Graphical abstract Image 1 Highlights • Supportless AgNFs with thorny structures were synthesized. • The best ORR activity among the reported Ag-based catalysts. • Superior long-term stability and an unusual methanol response. • Electron enrichment and high (110) facet exposure appear at thorny tips. • Their synergetic roles greatly contribute to high ORR activity. [ABSTRACT FROM AUTHOR]

Recently, ZnCdS nanocrystals (NCs) have attracted intense attention because of their specific optical properties and electrical characteristics. In this paper, a green and facile solution method is reported for the preparation of ZnCdS nanocrystals using dimethylsulfoxide as small molecular ligands. The ZnCdS nanocrystals are used as an interface modification material in the photovoltaic devices. It is found that the modification of ZnCdS on TiO 2 surface not only suppresses the recombination loss of carriers but also reduces the series resistance of TiO 2 /active layer. Consequently, both of the short circuit current ( J sc ) and the fill factor (FF) of the solar cells were significantly improved. Power conversion efficiency (PCE) of 7.75% based on TiO 2 /ZnCdS was achieved in contrast to 6.65% of the reference devices based on pure TiO 2 film in organic solar cells. Furthermore, the PCE of perovskite solar cells based on TiO 2 /ZnCdS was observed with 8.3% enhancement compared to that of pure TiO 2 -based ones. [ABSTRACT FROM AUTHOR]

Hole-transporting materials play an important role in perovskite solar cells. In this study, we introduced a novel hole-transporting material without p-type dopant, a tetrathiafulvalene derivative anchored with eight carboxyl groups (TTA) into inverted structure perovskite solar cells. The devices with TTA as hole-transporting layer showed high power conversion efficiency of 16.7%, which was 44.5% improvement compared with the reference devices without hole-transporting layer. The performance improvement was ascribed to three factors: 1) the better match of energy level between ITO and perovskite layer; 2) enhanced hole extraction at anode interface; 3) improved perovskite morphology. [ABSTRACT FROM AUTHOR]

A metal-ion-mediated cyclization of a linear peptide to the corresponding cyclohexadepsipeptide, a stereoisomer of �hirsutellide A, was studied. The presence of AgBF4 improved the cyclization yield from 14% to 61%. The effect of silver ion on the macrocyclization was further investigated by NMR and molecular mechanics calculations. [ABSTRACT FROM AUTHOR]