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Improving the transfer hydrogenation of N-heteroarenes is of key importance for various industrial processes and remains a challenge so far. We reported here a microcapsule-pyrolysis strategy to quasi-continuous synthesis S, N co-doped carbon supported Co single atom catalysts (Co/SNC), which was used for transfer hydrogenation of quinoline with formic acid as the hydrogen donor. Given the unique geometric and electronic properties of the Co single atoms, the excellent catalytic activity, selectivity and stability were observed. Benefiting from the quasi-continuous synthesis method, the as-obtained catalysts provide a reference for the large-scale preparation of single atom catalysts without amplification effect. Highly catalytic performances and quasi-continuous preparation process, demonstrating a new and promising approach to rational design of atomically dispersed catalysts with maximum atomic efficiency in industrial.

A facile and environmentally-friendly strategy for increasing antioxidant activity is a crucial issue for value-added lignin and lignin-carbohydrate complex (LCC) as alternative antioxidants. However, the antioxidant activities of lignin and LCC by the traditional solid-liquid extraction (SLE) methods were restricted by the relatively lower solubility induced from high molecular weight (Mw), and the less functional groups including, phenolic hydroxyl and carboxyl. To improve the antioxidantion of lignin and LCC, lithium chloride/dimethyl sulfoxide (LiCl/DMSO) solvent fractionation (LDSF) was conducted to increase the functional groups and reduce Mw, in which LiCl/DMSO acted triple roles as solvent, acid, and metal chloride catalyst for the depolymerization reaction synchronously. The β-O-4′ linkages were cleaved to release the phenolic hydroxyl, resulting in decreasing Mw; the hydroxyl of the side-chain of lignin was oxidized into carboxyl. Thus, the lignin (LD-RL) and LCC (LD-LCC) samples from LDSF had a higher syringyl (S)/guaiacyl (G) ratio, phenolic hydroxyl, and carboxyl contents, but less Mw than control groups from SLE. Consequently, they presented more excellent scavenging rates toward DPPH and ABTS radicals, up to 90%. This work provided panoramic perspectives and basics of the green and convenient approach to isolate and modify lignin and LCC for great antioxidantion with LDSF.

Lignin-carbohydrate complex (LCC) was proven to possess antioxidant activities. To understand structures and antioxidant activities of LCC, water-soluble LCC-stalk, LCC-sheath and LCC-leaf were isolated from ball-milled wheat straw stalk, sheath and leaf by successive dissolution in LiCl/DMSO solvent, water extraction and purification. LCCs were later structurally characterized by wet chemistry, chromatography and spectroscopy respectively. Their antioxidant activities were evaluated by ferric reducing antioxidant power (FRAP) and DPPH radical scavenging assays. The results showed that three LCCs were carbohydrate-rich (≈70%) and presented relatively narrow molecular weight distribution (PI 2.0). The lignin moieties of LCCs were mainly connected with β-O-4' structures, and phenyl glycoside and γ-ester linkages were main LCC linkages in LCCs. However, guaiacyl units were the predominant lignin units in LCC-stalk and LCC-sheath, while syringyl units were predominant in LCC-leaf. Intermolecular cross-linkages were mainly pCA-bridges in LCC-stalk and FA-bridges in LCC-sheath and LCC-leaf. Besides, LCC-sheath featured higher polysaccharide content exhibited higher molecular weight, fewer LCC linkages and better antioxidant activities (DPPH radical scavenging rate up to 74.91%) than both LCC-stalk (74.55%) and LCC-leaf (64.52%). This work helped to know LCCs in wheat straw well and inspire the application of LCC as potential antioxidants.

An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors and α-Fe2O3 as a support. The catalyst with Pt content as low as 0.2 wt% exhibits high activities, chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes. The conversion of nitrobenzene can reach 3170 molconv h−1 molPt−1 under mild conditions (30 °C, 5 bar), which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions. The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity, which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles. The unique surface properties of α-Fe2O3 play an important role in the reaction process. It provides active sites for hydrogen spillover and reactant adsorption, and ultimately completes the hydrogenation of the nitro group on the catalyst surface.

This paper proposes an enhanced discrete-time Markov chain algorithm in predicting dominant speaker(s) for multipoint video communication system in the presence of transient speech. The proposed algorithm exploits statistical properties of the past speech patterns to accurately predict the dominant speaker for the next time state. Non-linear weights-based coefficients are employed in the enhanced Markov chain for both the initial state vector and transition probability matrix. These weights significantly improve the time taken to predict a new dominant speaker during a conference session. In addition, a mechanism to dynamically modify the size of the transition probability matrix window/container is introduced to improve the adaptability of the Markov chain towards the variability of speech characteristics. Simulation results indicate that for an 11 conference participants test scenario, the enhanced Markov chain prediction algorithm registered an 85% accuracy in predicting a dominant speaker when compared to an ideal case where there is no transient speech. Misclassification of dominant speakers due to transient speech was also reduced by 87%.

Smart meters are progressively deployed to replace its antiquated predecessor to measure and monitor consumers’ consumption in smart grids. Although smart meters are equipped with encrypted communication and tamper-detection features, they are likely to be exposed to multiple cyber attacks. These meters may be easily compromised to falsify meter readings, which increases the chances and diversifies the types of energy theft. To thwart energy fraud from smart meters, utility providers are identifying anomalous consumption patterns reported to operation centers by leveraging on consumers’ consumption data collected from advanced metering infrastructure. In this paper, we put forward a new anomaly detection framework to evaluate consumers’ energy utilization behavior for identifying the localities of potential energy frauds and faulty meters. Metrics known as the loss factor and error term are introduced to estimate the amount of technical losses and capture the measurement noise, respectively in the distribution lines and transformers. The anomaly detection framework is then enhanced to detect consumers’ malfeasance and faulty meters even when there are intermittent cheating and faulty equipment, improving its robustness. Results from both simulations and test rig show that the proposed framework can successfully locate fraudulent consumers and discover faulty smart meters.

In this study, novel geopolymers based on solid wastes (coal gangue and red mud) were used in the adsorption of heavy metals (Pb2+ and Cu2+) from solution. The correlations between the composition and quantity of the geopolymer gels and heavy metal adsorption were investigated under various conditions using hydrochloric acid dissolution and spectroscopic techniques. The results showed that the geopolymer gel positively correlated with the Pb2+ and Cu2+ adsorption capacities in the absence of external silica and aluminum. Moreover, external silica and aluminum sources promoted Al2O3 and SiO2 dissolution in the raw materials, which increased and decreased the specific surface areas, respectively. All of the tested geopolymers exhibited Pb2+ and Cu2+ adsorption based on the Langmuir isotherm and the pseudo-second-order kinetic model, with adsorption maxima of 137.7 and 90 mg g−1, respectively. This research first determined the correlation between the geopolymer gel and its heavy metal adsorption performance, and demonstrated industrial waste-based geopolymers could be effectively applied for the removal of heavy metal which can help reduce the burden of waste management and provide new insights about the resource recovery of solid wastes.

The utility providers are estimated to lose billions of dollars annually due to energy theft. Although the implementation of smart grids offers technical and social advantages, the smart meters deployed in smart grids are susceptible to more attacks and network intrusions by energy thieves as compared to conventional mechanical meters. To mitigate non-technical losses due to electricity thefts and inaccurate smart meters readings, utility providers are leveraging on the energy consumption data collected from the advanced metering infrastructure implemented in smart grids to identify possible defective smart meters and abnormal consumers’ consumption patterns. In this paper, we design two linear regression-based algorithms to study consumers’ energy utilization behavior and evaluate their anomaly coefficients so as to combat energy theft caused by meter tampering and detect defective smart meters. Categorical variables and detection coefficients are also introduced in the model to identify the periods and locations of energy frauds as well as faulty smart meters. Simulations are conducted and the results show that the proposed algorithms can successfully detect all the fraudulent consumers and discover faulty smart meters in a neighborhood area network.

Anomalous transport is ever-present in many disordered organic semiconductor materials. The long-tail behavior observed in the transient photocurrent is a manifestation of anomalous transport. Owing to the fact that anomalous transport has dispersive and non-Gaussian transport dynamics, thus anomalous transport cannot be adequately described by the standard drift-diffusion equation which is a framework commonly used to model normal diffusive transport. In this work, we generalized the standard drift-diffusion equation to time fractional drift-diffusion equation (TFDDE) using the fractional calculus approach to model the anomalous transport in the regio-random poly(3-hexylthiophene) (RRa-P3HT) and regio-regular poly(3-hexylthiophene) (RR-P3HT). Physical elucidation of TFDDE is given by stressing how the influence of the multiple-trapping mechanisms and energy disorder lead to the long-tail behavior in the transient photocurrent curves. TFDDE is solved numerically using finite difference scheme to obtain the profiles of charge carriers density evolution and hence to reproduce the corresponding transient photocurrents of RRa-P3HT and RR-P3HT. Poisson solver is also included in the model to account for the fluctuation of localized electric field due to the evolution of charge carriers. It is found that charge carriers acquire additional energy from high electric field that helps them to escape from the trap centers more easily and then propagating at higher velocity, which yields higher transient current. Higher concentration of charge carriers can be generated at higher light intensity and they can occupy energy levels close to the mobility edge, where charge carriers will encounter smaller capturing rate and hop at a longer length in each hopping event. Thus, the transport dynamic of charge carriers at high light intensity is less dispersive than that of the low light intensity. Besides, the transport dynamic of charge carriers in RR-P3HT is relatively less dispersive and has higher mobility than that of the RRa-P3HT since RR-P3HT has lower capturing rate and is less energy disordered.

Optimized giant magnetoimpedance effect of Fe 75.5 Cu 1 Nb 3 Si 13.5 B 7 amorphous ribbon/Fe 80 Ga 20 film composites has been investigated. FeCuNbSiB amorphous ribbons as the substrates are commercially available, magnetostrictive FeGa films are deposited on one or both sides of the ribbons by ion-beam sputtering. Compared with the GMI curves without FeGa layer, the GMI effect of FeCuNbSiB amorphous ribbon has been obviously improved with FeGa film covered (from 4% to 16%). Moreover, the details exhibit an interesting phenomenon: at a certain frequency, when the FeGa film covered on one side of the ribbon, the GMI ratio decreases with the thickness of the FeGa film; however, when the FeGa films covered on both sides of the ribbon, the GMI ratio increases with the thickness of the FeGa film. We mainly attribute the reason to strain-induced anisotropy, which is induced by magnetostrictive effect under a longitudinal applied magnetic field.

The gastrointestinal endoscopy in this study refers to conventional gastroscopy and wireless capsule endoscopy (WCE). Both of these techniques produce a large number of images in each diagnosis. The lesion detection done by hand from the images above is time consuming and inaccurate. This study designed a new computer-aided method to detect lesion images. We initially designed an algorithm named joint diagonalisation principal component analysis (JDPCA), in which there are no approximation, iteration or inverting procedures. Thus, JDPCA has a low computational complexity and is suitable for dimension reduction of the gastrointestinal endoscopic images. Then, a novel image feature extraction method was established through combining the algorithm of machine learning based on JDPCA and conventional feature extraction algorithm without learning. Finally, a new computer-aided method is proposed to identify the gastrointestinal endoscopic images containing lesions. The clinical data of gastroscopic images and WCE images containing the lesions of early upper digestive tract cancer and small intestinal bleeding, which consist of 1330 images from 291 patients totally, were used to confirm the validation of the proposed method. The experimental results shows that, for the detection of early oesophageal cancer images, early gastric cancer images and small intestinal bleeding images, the mean values of accuracy of the proposed method were 90.75%, 90.75% and 94.34%, with the standard deviations (SDs) of 0.0426, 0.0334 and 0.0235, respectively. The areas under the curves (AUCs) were 0.9471, 0.9532 and 0.9776, with the SDs of 0.0296, 0.0285 and 0.0172, respectively. Compared with the traditional related methods, our method showed a better performance. It may therefore provide worthwhile guidance for improving the efficiency and accuracy of gastrointestinal disease diagnosis and is a good prospect for clinical application.

Background and Aims Endoscopic submucosal tunnel dissection (ESTD) has been used for dissection of large esophageal neoplastic lesions, but there are still some technical problems in treating circumferential superficial esophageal neoplastic lesions. This study aimed to assess the efficacy and safety of endoscopic submucosal multi-tunnel dissection (ESMTD) for circumferential superficial esophageal neoplastic lesions in selected patients followed up for 1 to 12 months. Methods From July 2014 to February 2015, the first series of 7 consecutive patients with circumferential superficial esophageal neoplastic lesions underwent ESMTD at our endoscopic center. The macroscopic types were classified according to the Paris endoscopic classification of superficial neoplastic lesions. Results The average length of lesions was 6.1 cm in 7 selected patients. The operative time ranged from 69 to 169 minutes (mean 121 minutes). En bloc dissection with negative basal margins was achieved in all lesions without serious intraoperative adverse events. Esophageal stricture was observed in all patients 1 to 3 months after the operation and was relieved after a retrievable metal stent was placed or esophageal water balloon dilatation was performed; however, one patient died of cerebral infarction 2 months after ESMTD. Conclusions ESMTD is feasible, safe, and effective for the treatment of circumferential superficial esophageal neoplastic lesions in select patients.

Carcinogenesis was postulated as the result of the local buildup of strong acids such as hydrogenchloride which may trigger metastasis. A previous study revealed that bicarbonate raised tumor pH and suppressed metastases. The phosphate groups in DNA on neutrophil extracellular traps possess hydrogen bonding capacity and can accept protons. The proteins commonly found in neutrophil extracellular traps such as CCDC25, myeloperoxidase (MPO), histone H3, peptidylarginine deiminase 4 (PAD4) possess basic amino acid content at about 20.2%, 12.8%, 24.3% and 13.0% respectively, which attracts anions such as chloride. The striking 20.2% basic amino acid content in CCDC25 is similar to that of typical oncoproteins. Local hydrogenchloride may be the dominant impetus for metastasis, accounting for the anticancer effects of virtually all weak organic acids, acetic acid and lactic acid in particular.

Although CeO2-supported Au single atoms (Au1/CeO2) have great potential in preferential oxidation of CO (PROX) reaction, the large-scale synthesis of such single-atom catalysts (SACs) is still greatly challenging. Herein, we develop a dry ball milling method for the mass production of Au1/CeO2 SACs in large quantities (>1 kg). The as-prepared Au1/CeO2 SACs were demonstrated as highly active, selective, and stable catalysts for PROX at 120 °C with 100% CO conversion. The TOFs of Au1/CeO2 SACs for H2 oxidation at 120 °C (

Carbon fiber/Fe-based soft magnetic alloys coaxial composites have been prepared and the enhanced giant magnetoimpedance effect has been investigated by applying a tensile stress. Carbon fibers as the inner core are commercially available, the outer layers respectively are Fe, Ni, FeNi and FeCo alloys, which are fabricated by electrochemical deposition. The composite with Fe80Ni20 alloy shows the best static magnetic property and giant magnetoimpedance ratio (about 26%) compared to other metals or alloys without tensile stress at 70 MHz. When applying a tensile stress, the giant magnetoimpedance ratios of all samples show large improvements. With the increase of the tensile stress, the ratio increases to the maximum value (about 200%) when the tensile stress is 350 MPa, which is about eightfold over the original sample and higher than traditional materials.

The ferrimagnetic mixed-spin Ising model on a decorated Bethe lattice with the coordination number q , consisting of three kinds of magnetic atoms, is exactly solved here. We mainly analyze the critical temperature curves and the sub-lattice and total magnetization curves in this model. The effect of uniaxial single-ion anisotropy acting on two different kinds of decorated atoms and next-nearest-neighbor interaction is taken into account in particular. It has been found that the critical temperature versus uniaxial single-ion anisotropy dependence is not a monotonically increasing function for some chosen parameters. And there is also a reentrant phase transition with the coordination number q equal to 4 in the narrow region of the uniaxial single-ion anisotropy.

A kind of highly efficient and low cost supported-Pt catalyst for oxidation of toluene is obtained through controlling both the chemical state of Pt active sites and surface properties of supports. The optimized Pt/Al2O3 catalyst with Pt loading as low as 0.1 wt% could completely convert toluene (1000 ppm) to CO2 at about 180 ℃ under a space velocity of 24,000 mL g−1 h−1. It also exhibits a high stability and moisture resistance properties under reaction atmosphere. TOF value calculated with the dispersion of Pt can reach 0.0685 s-1, representing a high utilization efficiency of Pt. A series of characterizations are carried out to investigate the key factors affecting the catalytic performance of Pt/Al2O3, and disclose the concrete role of Pt and Al2O3 in the activation of molecular oxygen and toluene. In situ DRIFTS and EPR results show that Pt is the active center for O2 activation. Metallic Pt nanoparticles (Pt0) can activate the molecular O2 even at room temperature. Al2O3 offers sites for the adsorption of toluene and desorption of CO2 product. The weak and medium strength of acid-base sites favorite the adsorption and desorption process. The oxidation of toluene over Pt/Al2O3 obeys modified L-H mechanism. The synergistic effect of metallic Pt nanoparticles and suitable Al2O3 support is critical for obtaining highly efficient Pt-based catalysts with low Pt contents for toluene oxidation.

We present a novel image denoising method based on multiscale sparse representations. In tackling the conflicting problems of structure extraction and artifact suppression, we introduce a correlation coefficient matching criterion for sparse coding so as to extract more meaningful structures from the noisy image. On the other hand, we propose a dictionary pruning method to suppress noise. Based on the above techniques, an effective dictionary training method is developed. To further improve the denoising performance, we propose a multi-stage sparse coding framework where sparse representations are obtained in different scales to capture multiscale image features for effective denoising. The multi-stage coding scheme not only reduces the computational burden of previous multiscale denoising approaches, but more importantly, it also contributes to artifact suppression. Experimental results show that the proposed method achieves a state-of-the-art denoising performance in terms of both objective and subjective quality and provides significant improvements over other methods at high noise levels.

An improved fabrication technique for conventional hot-pressed membrane electrode assemblies (MEAs) with carbon supported cobalt triethylenetetramine (CoTETA/C) as the cathode catalyst is investigated. The V – I results of PEM single cell tests show that addition of glycol to the cathode catalyst ink leads to significantly higher electrochemical performance and power density than the single cell prepared by the traditional method. SEM analysis shows that the MEAs prepared by the conventional hot-pressed method have cracks between the cathode catalyst layer and Nafion membrane, and the contact problem between cathode catalyst layer and Nafion membrane is greatly suppressed by addition of glycol to the cathode catalyst ink. Current density–voltage curve and impedance studies illuminate that the MEAs prepared by adding glycol to the cathode catalyst ink have a higher electrochemical surface area, lower cell ohmic resistance, and lower charge transfer resistance. The effects of CoTETA/C loading, Nafion content, and Pt loading are also studied. By optimizing the preparation parameters of the MEA, the as-fabricated cell with a Pt loading of 0.15 mg cm −2 delivers a maximum power density of 181.1 mW cm −2 , and a power density of 126.2 mW cm −2 at a voltage of 0.4 V.

A new efficient image codec called embedded wavelet coding based on list structure (EWCBL) is proposed in this paper. By combining the techniques of morphological representation and quadtree partitioning, EWCBL effectively exploits both within-subband clustering and cross-subband similarity of wavelet coefficients. Based on the list structure, a fine fractional bit-plane coding is employed to achieve excellent rate-distortion performance. The patterned morphological dilation is introduced to greatly reduce the redundant test operations. Experimental results show that the proposed EWCBL outperforms state-of-the-art embedded codecs for both lossy and lossless compression. Moreover, the good performance and features of embeddedness and scalability are achieved with relatively low complexity.