•Acinetobacter junii YB was isolated from activated sludge and identified.•The strain exhibited efficient removal of ammonium at varying culture conditions.•Hydroxylamine, nitrite and nitrate could ...be utilized by strain YB.•The strain showed capacities for aggregation and hydrophobicity.
A novel heterotrophic nitrifying bacterium was isolated from activated sludge and was identified as Acinetobacter junii YB. The strain exhibited efficient heterotrophic nitrification–aerobic denitrification ability at a broad range of ammonium loads and had the capability to utilize hydroxylamine, nitrite and nitrate as a sole nitrogen source. Based on the nitrogen removal and enzyme assay, the nitrogen removal pathway was speculated to be achieved through heterotrophic nitrification coupled with aerobic denitrification. In addition, single-factor experiments showed that efficient heterotrophic nitrification and growth of strain YB occurred with succinate as the carbon source, pH 7.5, 37°C, and high C/N ratio and dissolved oxygen. Furthermore, the new isolate showed capacities for aggregation and hydrophobicity. Regular variations of the flocculating ability and relative hydrophobicity were observed during the whole cultivation. The ability to perform heterotrophic nitrification–aerobic denitrification and cell aggregation demonstrated the great potential of the strain YB for future applications.
To meet the demands for screening out the optimal utilization channel for biomass from wheat straw, a number of researches have been reported in the comprehensive utilization about wheat straw ...including cellulose, hemicellulose and lignin. By reviewing the research status, processing method and comprehensive application of wheat straw, this paper summarizes the application fields, main pretreatment processing methods and bio-products of wheat straw. The paper also detailed novel pretreatment methods and bio-products during the comprehensive utilization of wheat straw. The assessment of more effective pretreatment methods has enabled the examination of wheat straw materials’ potential in the field of lignocellulose that, today, is little exploited. Bioconversion of lignocellulose to bioproducts e.g. bioethanol, biohydrogen and bio-composites has made achievements, however, several limitations such as pretreatment methods remain to be solved.
Extensive acidic soils, which suffer from accelerated soil acidification, are found in southern China. Soil acidity, aluminum toxicity, and nutrient deficiencies severely limited crop productivity in ...acidic soils. It has been widely reported that crop residue biochars can ameliorate acidic soils and increase crop productivity. Here, we summarized the positive effects and mechanisms involved in the correction of soil acidity, the alleviation of aluminum toxicity and the increase of soil pH buffering capacity by crop residue biochars. The carbonate, oxygen-containing functional groups and silicates in biochars are the major components responsible for their efficacy in amending acidic soils and resisting soil re-acidification. We conclude that application of crop residue biochars may be a better option than traditional liming to ameliorate acidic soils. Nonetheless, further researches into soil acidification are still required to address some issues that are controversial and poorly understood.
We develop a cellular automata model with finer discretization of space and higher walking velocities more than one cell. The model is used to simulate the evacuation process of pedestrians from a ...room with an exit. By simulation experiments, we find subtle effects of the discretization degree and walking velocities on the shape of the crowd near the exit, the evacuation time of each individual at different locations, and the evacuation efficiency of pedestrians formulated by two time indicators. We also investigate the relations between the exit flow and the exit width, formulated by the model, and compare the flow–width relations with those obtained by laboratory experiments in the existing literatures. This study is helpful for the validation and calibration of microscopic pedestrian models with discrete space representation and further narrowing the gap between these models’ theory and their application to engineering.
•Develop a cellular automata model with finer discretization of space.•Simulate the evacuation process of pedestrians from a room with an exit.•Find the effects of the discretization degree and walking velocities.•Investigate the relations of the exit flow to the exit width.
An enantioselective synthesis of spiropyrazolones from allenoate‐derived MBH acetates and pyrazolones through a phosphine‐mediated 4+1 annulation process has been developed. Spiropyrazolones were ...readily prepared in good chemical yields and good to high enantioselectivities. This is the first asymmetric example in which α‐substituted allenoates were utilized as a C4 synthon for phosphine‐catalyzed 4+1 annulation.
Optically enriched 4‐spiro‐5‐pyrazolones were prepared through phosphine‐catalyzed enantioselective 4+1 annulation. In this study, substituted pyrazolones were used as a C1 synthon in cycloaddition for the first time. Moreover, this is the first report in which α‐substituted allenoates were utilized in an asymmetric 4+1 annulation.
Future wireless networks have a substantial potential in terms of supporting a broad range of complex compelling applications both in military and civilian fields, where the users are able to enjoy ...high-rate, low-latency, low-cost and reliable information services. Achieving this ambitious goal requires new radio techniques for adaptive learning and intelligent decision making because of the complex heterogeneous nature of the network structures and wireless services. Machine learning (ML) algorithms have great success in supporting big data analytics, efficient parameter estimation and interactive decision making. Hence, in this article, we review the thirty-year history of ML by elaborating on supervised learning, unsupervised learning, reinforcement learning and deep learning. Furthermore, we investigate their employment in the compelling applications of wireless networks, including heterogeneous networks (HetNets), cognitive radios (CR), Internet of Things (IoT), machine to machine networks (M2M), and so on. This article aims for assisting the readers in clarifying the motivation and methodology of the various ML algorithms, so as to invoke them for hitherto unexplored services as well as scenarios of future wireless networks.
Microfluidics have aroused a new surge of interest in recent years in environmental and energy areas, and inspired novel applications to tackle the worldwide challenges for sustainable development. ...This book aims to present readers with a valuable compendium of significant advances in applying the multidisciplinary microfluidic technologies to address energy and environmental problems in a plethora of areas such as environmental monitoring and detection, new nanofluid application in traditional mechanical manufacturing processes, development of novel biosensors, and thermal management. This book will provide a new perspective to the understanding of the ever-growing importance of microfluidics.
Next-generation wireless networks are expected to support extremely high data rates and radically new applications, which require a new wireless radio technology paradigm. The challenge is that of ...assisting the radio in intelligent adaptive learning and decision making, so that the diverse requirements of next-generation wireless networks can be satisfied. Machine learning is one of the most promising artificial intelligence tools, conceived to support smart radio terminals. Future smart 5G mobile terminals are expected to autonomously access the most meritorious spectral bands with the aid of sophisticated spectral efficiency learning and inference, in order to control the transmission power, while relying on energy efficiency learning/inference and simultaneously adjusting the transmission protocols with the aid of quality of service learning/inference. Hence we briefly review the rudimentary concepts of machine learning and propose their employment in the compelling applications of 5G networks, including cognitive radios, massive MIMOs, femto/small cells, heterogeneous networks, smart grid, energy harvesting, device-todevice communications, and so on. Our goal is to assist the readers in refining the motivation, problem formulation, and methodology of powerful machine learning algorithms in the context of future networks in order to tap into hitherto unexplored applications and services.
Recently, hybrid satellite-terrestrial networks (H-STNs) are expected to support extremely high data rates and exponentially increasing demands of data, which require new spectrum sharing and ...interference control technology paradigms. By achieving an efficient spectrum sharing among H-STN, traffic offloading is a promising solution for boosting the capacity of traditional cellular networks. In this paper, a software-defined network-based spectrum sharing, and traffic offloading mechanism is proposed to realize the cooperation and competition between the ground base stations (BSs) of the cellular network and beam groups of the satellite-terrestrial communication (STCom) system. Assume that all BSs are operated by the same mobile network operator (MNO). Under the cooperation mode, all the BSs stop occupying a corresponding channel, and a selected beam group of the satellite helps offload the traffic from the BSs by exclusively using this channel. To facilitate the offloading negotiation between the MNO and satellite, we design a second-price auction mechanism which presents positive allocative externalities, i.e., other uncooperative beam groups of the satellite can benefit from the cooperation between BSs and the beam group performing offloading. Meanwhile, the unique optimal biding strategies for different beam groups of the satellite to achieve the symmetric Bayesian equilibrium as well as the expected utility of the MNO are derived and obtained in this paper. The performance of the proposed traffic offloading mechanism is validated in the simulations, which also reveal that there exists the unique optimal offloading threshold for the MNO to achieve the maximum expected utility.
The dual role of biochar for inhibiting soil acidification induced by nitrification was determined through two-step incubation experiments in this study. Ca(OH)2 or biochar was added respectively to ...adjust soil pH to the same values (pH 5.15 and 5.85), and then the amended soils were incubated in the presence of urea for 70 days. The results showed that compared with Ca(OH)2 treatment, both rice straw biochar and peanut straw biochar inhibited the decrease in soil pH and the increase in exchangeable acidity during the incubation. The application of biochars suppressed soil nitrification during the incubation, and thus reduced 7.5 mmol kg−1 and 1.4 mmol kg−1 protons released from nitrification compared to Ca(OH)2 treatments. Compared with Ca(OH)2 treatment, the ammonia-oxidizing bacteria population size was decreased by 8% and 12% in rice straw biochar and peanut straw biochar treatments respectively, which was the main responsibility for the inhibited nitrification after biochar application. In addition, the application of rice straw biochar and peanut straw biochar increased soil pH buffering capacity (pHBC) respectively by 22% and 32%. The increased pHBC played the main role (75%) in inhibiting the acidification of the soil amended with peanut straw biochar, while the rice straw biochar inhibited soil acidification mainly through suppressing nitrification during the incubation. Overall, compared with lime application, biochars can inhibit soil acidification caused by urea application through suppressing the nitrification process and improving the resistance of soils to acidification. The crop residue biochars presented a longer-lasting effect on ameliorating acidic soils than mineral lime.
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•Biochar played a dual role in inhibiting soil acidification from nitrification.•Biochar decreased proton release through suppressing soil nitrification.•Biochar increased soil pH buffering capacity and the resistance to acidification.•Biochar would be a better option to ameliorate acidic soils than liming.
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