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Growing computation requirements in emerging intelligently connected vehicle (ICV) networks has posed a big challenge for vehicles to process computation-intensive tasks on-board, and thus computation partition and offloading plays a critical role. Owing to broadcast nature of wireless channels, confidential messages without proper security protection in ICVs may be easily exposed to malicious users. In this paper, a mobile crowdsourcing (MCS) based mobile crowd computing framework for ICV networks is proposed, where multiple vehicles act as workers to provide computing services for end user (EU). In particular, artificial noise (AN) assisted physical (PHY) layer security approaches are used to enhance the security in offloading links. Ergodic secrecy rates in different offloading phases in time-varying channels are derived. In addition, an incentive-driven mechanism is introduced to encourage workers to share their idle computing resources, and an optimization problem is formulated to minimize the overall price paid for computing tasks, subject to energy consumption and delay constraints. Finally, Monte Carlo simulations verify the analysis on the ergodic secrecy rates.

Vehicle-to-vehicle (V2V) underlay cellular communication plays an important role in the fifth-generation (5G) and beyond communications and its security issues attract a lot of attention. Physical layer security, which explores channel characteristics to protect wireless communications, is very attractive due to its low latency. This paper focuses on secrecy capacity maximization in V2V underlay cellular communications, where the secrecy capacity of vehicular user equipments (VUEs) is optimized first, followed by sum proportional fairness function optimization for both VUEs and cellular user equipments (CUEs). The optimization problems can be solved in two sub-problems, e.g., power and subcarrier allocation problems. The power allocation can be done with the first strategy using a one-dimensional searching algorithm, whereas a genetic algorithm (GA) is used to solve the second optimization problem. In addition, as VUEs share uplink resources with CUEs, the co-channel interference exists and the subcarrier allocation sub-problem is a 3D search problem, which is solved by a two-step iterative Hungarian algorithm (IHA). Finally, simulations are performed to validate the performance of the proposed schemes.

This article aims to provide a comprehensive overview on PHY layer security assisted ICV networks. Beginning with a discussion from a general perspective of the ICV network architecture, this work summarizes the major security threats faced by ICV networks. To achieve confidential data transmission with a low latency and a high data rate, several physical layer security schemes are surveyed in this article, which include RRM, cooperative jamming, multi-antenna technologies, and PHY-layer key generation. In addition, the performances of the aforementioned schemes are compared in terms of different aspects, followed by a discussion on some major challenges that need to be tackled in the implementation of ICV networks.

In order to synthesize adsorbent that can effectively absorb heavy metals in a simple and economical way, this study described the fabrication of adsorbents based on cellulose acetate (CA). CA modified first by polyethyleneimine grafting (CAP) and then by ethylenediamine (CAPE) for enhancing Cu(II) and Pb(II) removal from water. The physico-chemical properties of the modified celluloses were analyzed. It was found that the adsorption functional groups (amino groups) were successfully grafted on cellulose and CAP converted from semi-crystalline to cellulose II after enhancement of ethylenediamine (EDA). Adsorption isotherm results showed that the Cu(II) and Pb(II) removal efficiency by CAPE was significantly higher than that by CAP, and CAP showed a higher adsorption capacity of Cu(II) and Pb(II) than CA, of which the adsorption isotherm modeled with Langmuir isotherms well. The adsorption capacity can significantly be affected by ionic strength and humic acid. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) results demonstrated the complexation between amino groups and Cu(II)/Pb(II) played an important role for adsorption onto CAPE.

The advanced oxidation process of peroxymonosulfate activated by solid catalyst is one of the main technologies to solve the pollution of antibiotics in water environment.In this work, a series of composites (MCW) containing Mn, Co, and W were synthesized using green ball milling, which does not produce the three wastes (waste gas, waste water and industrial residue). It shows a unique and high catalytic activity for peroxymonosulfate-based degradation of doxycycline (DC) under the pH condition between 4 and 9, and it can be reused five times. MCW composites remove DC using singlet oxygen and superoxide free radicals, as well as a large number of oxygen vacancies for electron storage. The formation rate of free radicals is determined by the conversion rates of Mn3+/Mn2+ and Co3+/Co2+. In addition, there are three ways to degrade DC to form 18 kinds of intermediates, and the toxicity of all the intermediates were predicted by ECOSAR program. The highly active catalysts obtained using a green synthetic route for the activation of peroxymonosulfate show a great potential for decontamination of antibiotics wastewater.

Nanoplastics (NPs) nano-scale effects and have strong mobility, posing potential risks to ecosystems and human health. Therefore, it is of great significance to study the interactions of minerals and NPs in water to understand the migration, transformation, and fate of NPs in the environment. This study investigated the flocculation of NPs on layered double hydroxides (LDHs) in water via heteroaggregation under various conditions such as different Mg/Al ratios of LDHs, calcination temperatures, coexisting ions, solution pH, and contact time. We found that the overall reaction achieved high efficiency that almost surpassed 70% and varied with solution pH. The highest flocculation performance (85.87%) was achieved at a Mg:Al ratio of 3:1, followed by 4:1 and 2:1. Moreover, the highest removal rate (80.85%) of NPs on cLDHs was achieved at calcination temperature of 300 °C. The heteroaggregation mechanism, bonding type, and interface reaction of the NPs–LDHs system were analyzed using the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, spectroscopy, and microscopy. At short separation distance within 5 nm, the total interaction energy was governed by electrostatic repulsion. However, at longer distance, the interparticle forces became dominated by van der Waals and electrostatic attractions, leading to attachment of two types of particles. The NPs could be removed by attachment onto the surface of LDHs without forming other functional groups. However, the calcined LDHs and those prepared by hydrothermal reactions showed different attachment morphologies under scanning electron microscopy, which revealed the mechanisms of surface attachment and encased precipitation. These results provided new insights and theoretical support for controlling NPs pollution in surface water, which could reduce the risks of NPs to ecosystems and human health.

Advanced oxidation processes based on persulfate activation can produce strong reactive oxygen species, which can effectively degrade a variety of organic pollutants. However, finding cost-effective activation methods and materials have become the key in the research process of this oxidation technology. With the discovery of the catalytic activity of biochar, the application of carbonaceous materials in persulfate activation has recently emerged. In this study, recyclable magnetic biochar was prepared from dewatered piggery sludge, and was used to activate peroxymonosulfate to degrade antibiotic tetracycline. Results showed that the catalytic activity of magnetic biochar was stronger than that of unmagnetized sludge biochar, and magnetic biochar showed better separation and sustainability in recovery and reuse. Neutral pH condition was also favorable for biochar and magnetic biochar to activate peroxymonosulfate. Peroxymonosulfate activation using magnetic biochar is an economical, efficient and environmentally friendly method for organic pollutants degradation.

Zeolite-Mg/Fe chloride dual enhanced coagulation is a cost-effective method for advanced treatment of swine wastewater, but the sludge generated after the enhanced coagulation remains to be a problem. In this study, the precipitate from a swine wastewater coagulation unit was regenerated by pyrolysis treatment in an O2-limited environment to develop a high efficient adsorbent (biochar-mineral composite, BMC) for the removal of Pb(II) from wastewater. SEM images indicate that complex Mg/Fe oxides and sludge biochar gathered around zeolite particles. Effects of different influencing factors such as Pb(II) initial concentration, pH, adsorption time and ion concentration on the adsorption performance were investigated. The results show that the Langmuir isotherm model can better express the adsorption of Pb(II) on BMC than Freundlich model and Temkin model. BMC pyrolyzed at 500 °C showed the maximum adsorption capacity of 450.58 mg/g under experimental condition of 25 °C, 100 mg/L Pb(II) initial concentration and the initial pH of 5.6. The adsorption mechanisms on BMC mainly include ion exchange, electrostatic interaction. Therefore, it is a cost-effective and environmental-friendly strategy to obtain biochar-mineral composite from recycled sludge, which can efficiently remove Pb(II) from wastewater.

Fenton reaction has been widely applied as a unique oxidative method in the treatment of industrial wastewater. However, it generates a massive amount of Fe sludge, which mostly contains other hazardous heavy metal waste that can harm the environment and humans. In this study, we proposed a sustainable method to eliminate the side effect of the Fenton reaction and turn the Fenton sludge containing Cu into an efficient catalyst in the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). The existence of Cu, which can increase the oxygen vacancies of the sludge, is attributed to the activation efficiency compared with Fe sludge devoid of Cu. X-ray diffraction and X-ray photoelectron spectroscopy results show that Fe is present in the form of α- Fe2O3 and γ- Fe2O3, whereas Cu mostly exists in the valence state of Cu(II). The influence of catalyst and PMS dosage, pH, and recycling times on the PMS reaction is illustrated. OH , SO4 − O2– and 1O2 are the critical reactive oxygen species. TC can be decomposed into CO2 and H2O through six possible pathway processes with these free radicals. Given its sustainable treatment and high catalytic efficiency, dealing with Fe sludge that contains heavy metals serves as a modal practice for harmful waste treatment and can be popularized for a broader application.

Hydrothermal carbonization is a novel technology for dewatering of sewage sludge. Layered double hydroxides (LDHs) are a widely used functional material, which can be prepared by hydrothermal method. In this study, we proposed a new process combining hydrothermal carbonization of sludge and in-situ preparation of LDHs. The addition of Mg and Al salts (as LDHs precursor) to the slurry before hydrothermal treatment can act as a sludge conditioner to effectively accelerate the sludge sedimentation. The obtained products hydrochar/LDHs (HL) composites with various mass ratios were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that the well-crystallized LDHs slice is thinner after combining with hydrochar. The HL products can be used as a highly effective adsorbent for removal of Pb2+ from water. The adsorption experiment results showed that the adsorption behavior of Pb2+ onto HL composites can be well expressed by a pseudo-second-order kinetic model and Langmuir isotherm with the maximum adsorption capacity of 62.441 mg/g. Ionic strength had no significant effect on the adsorption capacity. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectra indicated that the adsorption mechanisms of Pb2+ by HL composites mainly included electrostatic interaction and surface coprecipitation. Therefore, this is a cost-effective method to obtain a high efficiency adsorbent.

Aberrant expression of microRNAs (miRNAs) has been widely recognized to play critical roles in the pathogenic processes of colon cancer. However, the expression and functions of miR-3653 in colon cancer remain uncovered. This study revealed for the first time that miR-3653 expression was significantly decreased in colon cancer tissues and cell lines. MiR-3653 overexpression led to decreased migration and invasion of HCT116 cells while miR-3653 knockdown resulted in opposite influence of the metastatic behaviors of HT29 cells. qRT-PCR and western blot demonstrated that miR-3653 suppressed the epithelial-mesenchymal transition (EMT) of colon cancer cells using both gain- and loss- of function assay. Mechanically, miR-3653 was found to interact with the 3'-UTR of Zeb2 through the complementary sequences and inhibited the expression of Zeb2 in colon cancer cells. Rescue experiments demonstrated that the inhibitory effect of miR-3653 overexpression on cell metastasis and EMT was abrogated by forced expression of Zeb2. This study demonstrates that miR-3653 suppresses the metastasis and EMT of colon cells by targeting Zeb2, and serves as a promising biomarker and therapeutic target in colon cancer.

Performance of automatic speech recognition system drops dramatically in the presence of background noise unlike the human auditory system which is more adept at noisy speech recognition. This paper proposes a novel auditory modelling algorithm which is integrated with a feature extraction front-end. The proposed algorithm simulates properties of the human auditory system and applies it to the speech recognition system to enhance its robustness. It integrates simultaneous masking, forward masking and temporal integration effects into traditional mel-frequency cepstral coefficients (MFCC) feature extraction algorithm for robust speech recognition. The proposed method sharpens the power spectrum of the signal in both the frequency domain and the time domain. Experiments carried out on AURORA2 database show that the word recognition rate using our proposed feature extraction method has been effectively increased.