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HIGHLIGHTS-Current practice for managing nitrogen (N) use for cereal production are not environmentally sustainable. Over-use of N fertilizers is a global problem for millions of farmers who must decide on N applications-whether, when and how much.-A combination of improved advice on N management for specific cropping regimes is required, together with a breeding target of new commercial crop varieties with sustainable yields and a low N requirement.-While N use efficiency (NUE) has been a useful concept for quantifying the genetic differences in N uptake and utilization, the concept of an economic N optimum derived from N yield dose-response curves may provide new insights for lowering the N requirement Highlights

Indefinite optical properties, which are typically characterized by hyperbolic dispersion relations, have not been observed in naturally occurring materials, but can be realized through a metamaterial approach. We present here the design, fabrication and characterization of nanowire metamaterials with indefinite permittivity, in which allangle negative refraction of light is observed. The bottom-up fabrication technique, which applies electrochemical plating of nanowires in porous alumina template, is developed and demonstrated in achieving uniform hyperbolic optical properties at a large scale. We developed techniques to improve the uniformity and to reduce the defect density in the sample. The non-magnetic design and the off-resonance operation of the nanowire metamaterials significantly reduce the energy loss of electromagnetic waves and make the broad-band negative refraction of light possible.

Power transformers play a vital role in power transmission systems from the energy source to the consumption center. In situ diagnostics of the performance of power transformers provides a variety of benefits to ensure reliable electricity transmission. Immunity to electromagnetic interference, high sensitivity, high insulation as well as small dimensions of optical sensing make it very attractive for applications in power transformer monitoring. This paper presents a critical review of various diagnostic methods for power transformers such as partial discharge, dissolved gases, temperature and other important sensing, and optical detection. The advantages and disadvantages of different monitoring methods are carefully discussed and assessed. Finally, the existing technical barriers and future prospects of optical monitoring methods for power transformers are presented.

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Advanced Persistent Threat (APT) poses a serious threat to cyber security, and its unique high unpredictability, deep concealment and grave harmfulness make the traditional network monitoring technology facing unprecedented challenges in the background of massive and complicated network traffic. This paper aimed for the urgent demand of APT network monitoring. Relying on the rapid development of big data analysis and cloud computing technology, to draw lessons from biology gene concept, we put forward a new connotation of the network gene to depict the semantic-rich behavior characteristics pattern of network applications. Through the organic combination of network protocol reverse analysis and the network data stream processing technology, we established a set of basic theories and technical architecture of network gene construction and calculation, forming a new detection framework for APTs to support the construction of intrusion-tolerant network ecological environment.

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High performance of bacterial extracellular electron transfer (EET) is essentially important for its practical applications in versatile bioelectric fields. We developed a facile one-step approach to dramatically boost the bacterial EET activity 75-fold by exogenous addition of ethylenediamine tetraacetic acid disodium salt (EDTA-2Na, 1 mM) into the electrochemical cells, where the anodic process of microbial EET was monitored. We propose that EDTA-2Na enables both the alternation of the local environment around the c-type cytochromes located on the outer membrane channels (OMCs), which therefore changes the redox behavior of OMCs in mediating the EET process, and the formation of densely packed biofilm that can further facilitate the EET process. As a synergistic effect, the highly boosted bacterial EET activity was achieved. The method shows good generality for versatile bioelectrical bacteria. We envision that the method is also applicable for constructing various bioelectric devices.