Showing papers by "Henan University of Technology published in 2019"

Finite/Fixed-Time Pinning Synchronization of Complex Networks With Stochastic Disturbances

Abstract: This brief proposes a unified theoretical framework to investigate the finite/fixed-time synchronization of complex networks with stochastic disturbances. By designing a common pinning controller with different ranges of power parameters, both the goals of finite-time and fixed-time synchronization in probability for the network topology containing spanning trees can be achieved. Moveover, with the help of finite-time stochastic stability theory, two types of explicit expressions of finite/fixed (dependent/independent on the initial values) settling times are calculated as well. One numerical example is finally presented to demonstrate the effectiveness of the theoretical analysis.

Microwave vacuum pyrolysis of waste plastic and used cooking oil for simultaneous waste reduction and sustainable energy conversion: Recovery of cleaner liquid fuel and techno-economic analysis

Abstract: Microwave vacuum pyrolysis was examined and compared to conventional pyrolysis for its technical and economic feasibility in co-processing of waste plastic and used cooking oil simultaneously to generate fuel product. The pyrolysis demonstrated beneficial process features with respect to high heating rate (29 °C/min) to provide fast heating, high process temperature for extensive cracking (581 °C), short process time (20 min), and low electrical energy consumption (0.38 kWh). The combined use of microwave vacuum pyrolysis and activated carbon reaction bed produced up to 84 wt% yield of liquid oil, containing light hydrocarbons and higher heating value (49 MJ/kg) than diesel and gasoline, hence showing great promise for application as fuel. The use of activated carbon reaction bed showed beneficial effect in creating a reduction environment that prevented the oxidation or formation of oxygenated by-products. A positive synergistic effect between waste plastic and used cooking oil was also observed. The liquid oil obtained from this pyrolysis approach presented a low oxygen and nitrogen content, and free of sulphur, showing ‘cleaner’ properties with respect to reduced char residues, sludge formation, corrosiveness, degradation of oil quality, and emission of undesired SOx and NOx during its utilization in combustion process. The techno-economic analysis indicated that this pyrolysis approach showed low production cost (USD 0.25/L compared to USD 0.523/L of diesel price in Malaysia). Our results demonstrate that microwave vacuum pyrolysis is potentially economically feasible and show promise as a sustainable approach for energy conversion in providing improved process features and production of cleaner liquid fuel.

ZIF-67-Derived N-Doped Co/C Nanocubes as High-Performance Anode Materials for Lithium-Ion Batteries

Abstract: Co nanoparticles embedded in nitrogen-doped carbon nanocubes (Co/NCs) for applications as anode materials in rechargeable lithium-ion batteries were synthesized by calcining Co-based metal-organic framework. Sizes of Co nanoparticles were ∼15 nm according to X-ray diffraction (XRD) and transmission electron microscopy. Electrochemical performances of the as-prepared anode nanocube composite at 700 °C showed a high initial capacity of 1375.1 mAh g-1 in the voltage range of 0.01-3.0 V at the current rate of 0.1 A g-1. After 100 cycles, capacity remained at 688.6 mAh g-1. Thereinto, the role of Co nanoparticles in electrochemical reaction was also elucidated by in situ XRD experiment. Capacity increase of Co/NCs at the high currents was observed, which are potentially caused by the activation of electrode and pseudocapacitance during cycling. High surface area and abundant mesopores contributed to the improved electrochemical performances of the anode, providing numerous pathways and sites for Li+ transfer and storage and accordingly contributing to pseudocapacitance capacity.

Conjugated Carbonyl Compounds as High-Performance Cathode Materials for Rechargeable Batteries

Abstract: In search for novel cathode materials for lithium, sodium, and potassium ion batteries, organic electrode materials are expected to be the next powerful candidates owing to their high theoretical c...

Yolk-Shell-Structured Bismuth@N-Doped Carbon Anode for Lithium-Ion Battery with High Volumetric Capacity.

Abstract: As an anode for lithium-ion batteries, metallic bismuth (Bi) can provide a superb volumetric capacity of 3800 mA h cm–3, showing perspective value for application. It is a pity that the severe volu...

An Efficient and Provably Secure Authenticated Key Agreement Protocol for Fog-Based Vehicular Ad-Hoc Networks

Abstract: The maturity of cloud computing, the Internet of Things technology, and intelligent transportation system has promoted the rapid development of vehicular ad-hoc networks (VANETs). To keep pace with real-world demands (mobility, low latency, etc.) in a practical VANETs deployment, there have been attempts to integrate fog computing with VANETs. To facilitate secure interaction in fog-based VANETs, we design a new authenticated key agreement protocol without bilinear pairing. This protocol achieves mutual authentication, generates a securely agreed session key for secret communication, and supports privacy protection. We also give a strict formal security proof and demonstrate how the proposed protocol meets the security requirements in the fog-based VANETs. We then evaluate the efficiency of the proposed protocol, and it shows the practicality of the protocol.

Effect of roasting treatment on the chemical composition of sesame oil

Abstract: Sesame oil is rich in highly concentrated bioactive components including tocopherols, phytosterols and lignans (e.g., sesamolin, sesamin, and sesamol). The chemical composition and quantification of oil extracted from roasted sesame seeds was investigated and compared with unroasted sesame oil in relation to health-promoting and potentially harmful substances (particularly polycyclic aromatic hydrocarbons, abbreviated as PAHs). With roasting, the peroxide value and color development of oils was elevated obviously while the total tocopherols and sesamolin decreased steadily. The acid values in the current experiment were expected to grow as the roasting time increased at the same temperature, and the acid value decreased in the first 30 min of roasting at 160 °C. Increased roasting temperature or time facilitates sesamol formation in sesame oil. The fatty acid profiles are almost independent of roasting conditions. There was a significant increase in PAHs with elevated temperatures and extended times. In general, favorable sensory qualities accompanied by a beneficial healthy composition of sesame oil may be attributed to the treatment by roasting at a temperature from 160 °C to 180 °C and a roasting time of less than 20 min.

T-PBFT: An EigenTrust-based practical Byzantine fault tolerance consensus algorithm

Abstract: Blockchain with these characteristics of decentralized structure, transparent and credible, time-series and immutability, has been considering as a promising technology. Consensus algorithm as one of the core techniques of blockchain directly affects the scalability of blockchain systems. Existing probabilistic finality blockchain consensus algorithms such as PoW, PoS, suffer from power consumptions and low efficiency; while absolute finality blockchain consensus algorithms such as PBFT, HoneyBadgerBFT, could not meet the scalability requirement in a large-scale network. In this paper, we propose a novel optimized practical Byzantine fault tolerance consensus algorithm based on EigenTrust model, namely T-PBFT, which is a multi-stage consensus algorithm. It evaluates node trust by the transactions between nodes so that the high quality of nodes in the network will be selected to construct a consensus group. To reduce the probability of view change, we propose to replace a single primary node with a primary group. By group signature and mutual supervision, we can enhance the robustness of the primary group further. Finally, we analyze T-PBFT and compare it with the other Byzantine fault tolerant consensus algorithms. Theoretical analysis shows that our T-PBFT can optimize the Byzantine fault-tolerant rate, reduce the probability of view change and communication complexity.

Transition-metal-free decarboxylative C3-difluoroarylmethylation of quinoxalin-2(1H)-ones with α,α-difluoroarylacetic acids

Abstract: A facile transition-metal-free decarboxylative radical coupling reaction of α,α-difluoroarylacetic acids with quinoxalin-2(1H)-ones has been developed. This methodology provided a highly attractive approach to synthesize a series of difluoroarylmethylated quinoxalin-2(1H)-ones that contain various functional groups in moderate to good yields under mild conditions. Moreover, experimental studies reveal that the CF2 group of α,α-difluoroarylacetic acids plays a vital role in this transformation.

Chemical Analysis and Simulated Pyrolysis of Tobacco Heating System 2.2 Compared to Conventional Cigarettes

Abstract: Introduction Tobacco Heating System 2.2 (THS 2.2, marketed as iQOS) is a heat-not-burn (HNB) tobacco product that has been successfully introduced to global markets. Despite its expanding market, few independent and systematic researches into THS 2.2 have been carried out to date. Methods We tested a comprehensive list of total particulate matter (TPM), water, tar, nicotine, propylene glycol, glycerin, carbon monoxide, volatile organic compounds, aromatic amines, hydrogen cyanide, ammonia, N-nitrosamines, phenol, and polycyclic aromatic hydrocarbon under both ISO and HCI regimes. We also simulated pyrolysis of THS 2.2 heating sticks and made comparisons with conventional cigarette tobacco fillers using comprehensive gas chromatography-mass spectrometry (GC × GC-MS) to determine whether the specially designed ingredients help reduce harmful constituents. Results Other than some carbonyls, ammonia, and N-nitrosoanabasine (NAB), the delivered releases from THS 2.2 were at least 80% lower than those from 3R4F. Tar and nicotine remained almost the same as 3R4F. Interestingly, the normalized yield of THS 2.2 to 3R4F under the HCI regime was lower than that under the ISO regime. Conclusions THS 2.2 delivered fewer harmful constituents than the conventional cigarette 3R4F. Simulated pyrolysis results showed that the lower temperature instead of specially designed ingredients contributed to the distinct shift. In particular, if smoking machines are involved to evaluate the HNB products, smoking regimes of heat-not-burn tobacco products should be carefully chosen. Implications To our knowledge, few independent studies of HNB products have been published. In this paper, a comprehensive list of chemical releases was tested systematically and compared to those from 3R4F. Although THS 2.2 generates lower levels of harmful constituents, the nicotine and tar levels were almost identical to 3R4F.The results should be discussed carefully in the future when assessing the dual-use with other conventional cigarettes, nicotine dependence of HNB products, etc. This study also suggests that regulatory agencies should pay attention to the smoking regimes that are adopted to evaluate HNB tobacco products.

Parallelized Convolutional Recurrent Neural Network With Spectral Features for Speech Emotion Recognition

Abstract: Speech is the most effective way for people to exchange complex information Recognition of emotional information contained in speech is one of the important challenges in the field of artificial intelligence To better acquire emotional features in speech signals, a parallelized convolutional recurrent neural network (PCRN) with spectral features is proposed for speech emotion recognition First, frame-level features are extracted from each utterance and, a long short-term memory is employed to learn these features frame by frame At the same time, the deltas and delta-deltas of the log Mel-spectrogram are calculated and reconstructed into three channels (static, delta, and delta-delta); these 3-D features are learned by a convolutional neural network (CNN) Then, the two learned high-level features are fused and batch normalized Finally, a SoftMax classifier is used to classify emotions Our PCRN model simultaneously processes two different types of features in parallel to better learn the subtle changes in emotion The experimental results on four public datasets show the superiority of our proposed method, which is better than the previous works

Surface‐Driven Energy Storage Behavior of Dual‐Heteroatoms Functionalized Carbon Material

Abstract: Oxygen/sulfur dual‐functionalized carbon (OS–C) is obtained by chemically activating C6H4O4S, where the heteroatoms are in situ introduced into the carbon skeleton to form CO/CS bonds. The as‐proposed energy storage mechanism consists of three parts in different potential windows: Faradaic reactions → adsorption → intercalation. The electrode shows effective storage of Li/Na, providing lifetimes in excess of thousands of cycles.

Fabrication and characterization of Ag3PO4/TiO2 heterostructure with improved visible-light photocatalytic activity for the degradation of methyl orange and sterilization of E.coli

Abstract: Ag3PO4/TiO2 heterostructure photocatalysts were prepared by the hydrolysis of TiCl4 and NH3· H2O, microwave calcination, and chemical precipitation method. A series of techniques, such as XRD, SEM,...