The wastewater from coal-mine industry varies greatly and is resistant to biodegradation for containing large quantities of inorganic and organic pollutants. Microorganisms in activated sludge are responsible for the pollutants' removal, whereas the microbial community composition and structure are far from understood. In the present study, the sludges from five coal-mine wastewater treatment plants were collected and the microbial communities were analyzed by Illumina high-throughput sequencing. The diversities of these sludges were lower than that of the municipal wastewater treatment systems. The most abundant phylum was Proteobacteria ranging from 63.64% to 96.10%, followed by Bacteroidetes (7.26%), Firmicutes (5.12%), Nitrospira (2.02%), Acidobacteria (1.31%), Actinobacteria (1.30%) and Planctomycetes (0.95%). At genus level, Thiobacillus and Comamonas were the two primary genera in all sludges, other major genera included Azoarcus, Thauera, Pseudomonas, Ohtaekwangia, Nitrosomonas and Nitrospira. Most of these core genera were closely related with aromatic hydrocarbon degradation and denitrification processes. Identification of the microbial communities in coal-mine wastewater treatment plants will be helpful for wastewater management and control.

Teaching English in a classroom setting where EFL learners were usually sitting at desks and doing English learning tasks using paper and pencil is inefficient. It has considerable potential problems that could lead to students learning in a passive state. More specifically, the teaching materials are inconsistent with students’ authentic experiences, which decreases the learning efficiency, learning motivation, and levels of interactivity. An annotatable multimedia E-reader (AME) was developed to address these problems. The provided various annotation tools to help students create dramas with authentic contexts. The study participants were 48 junior high school students and divided into the experimental group (EG) and control group (CG). Results revealed that learning English through drama with AME assistance in authentic contexts significantly improved the participants’ learning achievements. In other words, the learning achievements of the EG were superior to those of the CG. Moreover, the results indicated that different learning behaviors were significantly related to different learning achievements. Thus, the greater the diversity of learning behaviors practiced by the students in the drama activity in authentic contexts, the higher the students’ learning scores on different dimensions. Finally, the results indicated that using the AME in authentic contexts was beneficial for English learning through drama.

Facilitating navigation in pedestrian environments is critical for enabling people who are blind and visually impaired (BVI) to achieve independent mobility. A deep reinforcement learning (DRL)–based assistive guiding robot with ultrawide-bandwidth (UWB) beacons that can navigate through routes with designated waypoints was designed in this study. Typically, a simultaneous localization and mapping (SLAM) framework is used to estimate the robot pose and navigational goal; however, SLAM frameworks are vulnerable in certain dynamic environments. The proposed navigation method is a learning approach based on state-of-the-art DRL and can effectively avoid obstacles. When used with UWB beacons, the proposed strategy is suitable for environments with dynamic pedestrians. We also designed a handle device with an audio interface that enables BVI users to interact with the guiding robot through intuitive feedback. The UWB beacons were installed with an audio interface to obtain environmental information. The on-handle and on-beacon verbal feedback provides points of interests and turn-by-turn information to BVI users. BVI users were recruited in this study to conduct navigation tasks in different scenarios. A route was designed in a simulated ward to represent daily activities. In real-world situations, SLAM-based state estimation might be affected by dynamic obstacles, and the visual-based trail may suffer from occlusions from pedestrians or other obstacles. The proposed system successfully navigated through environments with dynamic pedestrians, in which systems based on existing SLAM algorithms have failed.

Appropriate resource allocation has great significance to enhance the energy efficiency (EE) for cooperative communication system. The objective is to allocate the resource to maximize the energy efficiency in single-cell multiuser cooperative communication system. We formulate this problem as subcarrier-based resource allocation and solve it with path planning in graph theory. A twolevel neural network model is designed, in which the users and subcarrier are defined as network nodes. And then we propose an improved intelligent water drops algorithm combined with Genetic Algorithm; boundary condition and initialization rules of path soil quantity are put forward. The simulation results demonstrate that the proposed resource allocation scheme can effectively improve the energy efficiency and enhance QoS performance.

The treated distillate aromatic extract (TDAE) is widely used in tread compounds. However, polycyclic aromatic hydrocarbons (PAHs) contained in TDAE is serious harm to the environment and human. In this paper, liquid polybutadiene (LPB) of different brands was used to replace TDAE to plasticize solution polymerized styrene-butadiene rubber/cis-1,4-polybutadiene rubber (SSBR/BR). The effects of liquid polybutadiene instead of TDAE on crosslinking network and mechanical properties of matrix rubber were studied. LPB could participate in vulcanization reaction (different from TDAE).The results showed that LPB effectively reduced the critical strain amplitude of Payne effect (ameliorated filler dispersion) compared with TDAE plasticizing SSBR/BR. The degree of crosslinking decreased slightly, but there was no significant difference in rolling resistance and wet skid resistance at the same sulfur content. Changing the sulfur content, the wet skid resistance of tread and tensile strength of SSBR/BR vulcanizate plasticized by LPB were significantly improved, and the effect of LPB with high 1,2-vinyl content was better. In a